Rozprawy doktorskie na temat „Insulin receptor gene”

The daf-2 gene is a key regulator of growth, metabolism and longevity in the nematode Caenorhabditis elegans. The DAF-2 receptor functions in a pathway that is analogous to mammalian insulin/insulin-like growth factor signalling and determines whether animals proceed with full reproductive development or arrest in a long-lived diapausal state known as the dauer larva. Temperature-sensitive hypomorphic mutants of daf-2 constitutively arrest as dauers when raised at non-permissive temperatures. At permissive temperatures the animals develop into adults that are long-lived compared to wild-type adults. These alleles of daf-2 can be separated into two distinct classes (1 and 2) based on their pleiotropic phenotypes. In addition to their phenotypic differences, the two classes also differ in their epistatic interactions with other genes involved in dauer formation, suggesting that the DAF-2 receptor has multiple signalling outputs. In this thesis I have investigated the nature of the daf-2 allele class difference using a range of methods, including sequence analysis and homology modelling of mutant receptors. This generated the prediction that signalling flux through the receptor is a determinant of the class difference, with class 2 alleles having an asymmetrical alteration in signal transduction through DAF-2. Experimental testing of these predictions suggest that some phenotypes such Eat and Unc may be associated with asymmetrical signalling, while others such as early larval arrest may be correlated with a reduction in receptor level at the plasma membrane. A comparative analysis of the DAF-2 receptor with its homologues from Caenorhabditis briggsae, Caenorhabditis remanei and the parasitic nematode Brugia malayi suggests the large C-terminal extension in the Caenorhabditis species, which shorter in Brugia and not present in vertebrates, is an adaptive trait that has evolved by exon duplication for rapid growth and development and may contribute to the shortevity of these species. In addition, I have also performed an analysis of ins-7 and ins-35, two putative ligands of DAF-2 that are differentially regulated by the transcription factor DAF-16, using RNAi. Knockdown of both these genes lead to slight lifespan extension (10-20%) at 20 °C in all genetic backgrounds and slight suppression (-10%) at 25 °C in long-lived daf-2 mutant backgrounds compared to controls. This suggests that INS peptides may function as agonists a 20 °C and antagonists at 25 °C, and that this behaviour may be independent of their transcriptional regulation.

Orientador: Mario Jose Abdalla Saad
Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas
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Resumo: Estudos recentes demonstram que a obesidade está associada com a resistência à insulina e com um estado de inflamação crônica subclínica. Os ¿Toll-Like Receptors¿ (TLRs) têm um papel fundamental na ativação do sistema imune através do reconhecimento de antígenos de microorganismos. O TLR4 é um subtipo de TLRs que é ativado pelo lipopolissacarídeo de bactérias gram-negativas e por outros agonistas, como os ácidos graxos saturados. A ativação do TLR4 estimula vias inflamatórias relacionadas à indução de resistência à insulina, como a JNK e a IKKß. Neste estudo, demonstrou-se que camundongos C3H/HeJ, que apresentam uma mutação inativadora do TLR4, estão protegidos da obesidade e da resistência à insulina induzidas por dieta hiperlipídica. Além disso, músculos sóleos isolados de camundongos C3H/HeJ estão protegidos da resistência à insulina induzida por ácidos graxos. Camundongos C3H/HeJ tratados com dieta hiperlipídica (DH) apresentam um menor ganho de peso, maior tolerância à glicose e maior sensibilidade à insulina em relação aos controles em DH. A análise morfométrica do tecido adiposo evidenciou que os adipócitos dos camundongos C3H/HeJ em DH são 30% menores em relação aos adipócitos dos camundongos controle tratados com a mesma dieta. Foi evidenciada uma maior fosforilação em tirosina do IRS-1 e maior fosforilação da Akt, após estímulo com insulina, em músculo, tecido adiposo e fígado de camundongos C3H/HeJ tratados com DH em relação aos controles. Observou-se uma maior ativação da JNK, da IKKß e da iNOS em músculo, tecido adiposo e fígado de animais controle tratados com DH quando comparado com camundongos C3H/HeJ tratados com a mesma dieta. O tratamento com palmitato reduziu a captação de glicose e a síntese de glicogênio em 40-50% em músculo sóleo isolado de camundongos controle, mas este efeito não foi observado em músculo sóleo isolado de camundongos C3H/HeJ. Em resumo, o nosso estudo demonstra que a inativação do TLR4 previne a obesidade induzida por dieta, a ativação da IKKß, da JNK, a resistência à insulina em camundongos em DH, além da resistência à insulina induzida por palmitato em músculo isolado. O estudo sugere que o TLR4 tem um papel importante na interligação entre o sistema imune inato e a resistência à insulina, sendo um possível alvo terapêutico para a obesidade, resistência à insulina e diabetes mellitus tipo 2
Abstract: Obesity is associated with insulin resistance and a state of abnormal inflammatory response. The Toll-like receptor 4 (TLR4) has an important role in inflammation and immunity and its expression has been reported in most tissues of the body, including the insulin-sensitive ones. Since it is activated by lipopolysaccharide (LPS) and saturated fatty acids, which are inducers of insulin resistance, TLR4 may be a candidate for participation in the cross-talk between inflammatory and metabolic signals. Here, we show that C3H/HeJ mice, which have a loss-of-function mutation in TLR4, are protected against the development of diet-induced obesity. In addition, these mice demonstrate decreased adiposity, increased oxygen consumption, a decreased respiratory exchange ratio, improved insulin sensitivity and enhanced insulin signaling capacity in adipose tissue, muscle and liver, as compared to control mice during high fat feeding. Moreover, in these tissues, control mice fed on a high fat diet show an increase in IKKß and JNK activity, which is prevented in C3H/HeJ mice. In isolated muscles from C3H/HeJ a protection from saturated fatty acid-induced insulin resistance is observed. Thus, TLR4 appears to be an important mediator of obesity and insulin resistance and a potential target for the therapy of these highly prevalent medical conditions
Doutorado
Ciencia Basica
Doutor em Clínica Médica

Thesis (M.A.) -- University of Maryland, College Park, 2005.
Thesis research directed by: Dept. of Kinesiology. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.

Breast cancer is the most common malignancy among women in the U.S. While many successful treatments exist for primary breast cancer, very few are available for patients with metastatic disease. The purpose of this study was to understand the role of Insulin Receptor Subtrate-2 (IRS-2) in breast cancer metastasis. IRS-2 belongs to the IRS family of cytoplasmic adaptor proteins that mediate signaling from cell surface receptors, many of which have been implicated in cancer. Although the IRS proteins are highly homologous in structure and have some complementary functions, growing evidence supports that the IRS proteins have unique roles in cancer. IRS-1 has been shown to promote tumor cell proliferation, while IRS-2 has been positively associated with cancer cell invasion, glycolysis and tumor metastasis. In the current work, we identified IRS-2 as a novel hypoxia-responsive gene in breast carcinoma cells. In contrast, IRS-1 expression does not increase in response to hypoxia, supporting the notion of their non-overlapping functions. Hypoxia promotes the adaptation and resistance of cancer cells to chemo- and radiation therapy, and also promotes tumor cell survival, invasion and metastasis by selecting for aggressive tumor cells that can survive under stressful low oxygen conditions. We have shown that IRS-2 upregulation in response to hypoxia promotes Akt signaling and tumor cell viability and invasion. We identified a cell context-dependent role for Hypoxia Inducible Factor (HIF) in the regulation of IRS-2 expression in hypoxia, with HIF-2 playing a more dominant role than HIF-1. We also demonstrate that binding of Snail, a regulator of the EMT, to the IRS-2 promoter keeps the chromatin in an open conformation that is permissive for HIF-dependent transcription of IRS-2 in hypoxia. IRS-2 is not upregulated by hypoxia in well-differentiated epithelial-like carcinoma cells that do not express Snail, implicating IRS-2 gene expression as part of the EMT programming. In summary, we have identified an endogenous mechanism by which cancer cells can shift the balance of IRS-1 and IRS-2 to favor IRS-2 expression and function, which promotes survival, invasion, and ultimately metastasis. Understanding the mechanism of IRS-2 regulation by hypoxia may reveal new therapeutic targets for metastatic breast cancer.

The metabolism of vitamin D commences with exposure of the skin to sunlight. The growing recognition of its role in insulin resistance, autoimmune disorders, infections, cancer, as well as the health of cells that influence physical and mental function have profound implications on how we define vitamin D requirements and why we should care whether they are met or not. Most of the actions of vitamin D are mediated by the vitamin D receptor (VDR), a protein whose gene sequence can vary, giving rise to polymorphic forms which are potent enough to affect the binding capacity of this protein to vitamin D. Some of these polymorphic forms of VDR gene may be associated with reduced effectiveness of vitamin D and hence predispose individuals to diseases such as type 2 diabetes and insulin resistance. An earlier study, the Surya Study, looked at the responsiveness of the South-Asian women living in Auckland to vitamin D. The research described here is an extension of this study and its focus was to identify the associations/linkages between certain polymorphic forms of the VDR gene and the disease conditions and intervention responsiveness in the same women. The first objective was to compare two well known techniques for genotyping single nucleotide polymorphisms (SNPs) of the VDR gene at the 3’ end, namely BsmI, ApaI and TaqI: the newer real-time polymerase chain reaction (qPCR) and the traditional restriction fragment length polymorphism polymerase chain reaction (RFLP-PCR) techniques. This comparison was performed to evaluate alternative methods for genotyping which consumed less time than RFLP-PCR. When the presence of each polymorphism by both the techniques was compared in this cohort of South-Asian women, it was found that RFLP-PCR proved to be a more reliable technique than qPCR for genotyping the VDR gene. Another objective of this project was to investigate the prevalence of the above three polymorphisms along with Cdx-2 and FokI SNPs which are present at the 5’ end of the VDR gene, in the population under study and their possible association with phenotypes such as vitamin D responsiveness and insulin resistance. These women were screened and biochemical data was collected during the earlier Surya Study. Of these, eighty-one women were then selected for intervention based on them having high insulin resistance (HOMA-IR>1.93) and serum 25(OH)D<50 nmol/L. Out of these eighty-one women, forty-two were given vitamin D supplement and thirty-nine were given a placebo for six months. Baseline and endpoint measurements included insulin resistance (HOMA-IR), insulin sensitivity (HOMA2%S) etc. How each individual responded to treatment in the intervention group was analysed in the context of the polymorphisms that they had. An association of insulin resistance with BsmI, ApaI and TaqI SNPs was observed in this cohort of 239 women. The response to insulin resistance in the vitamin D supplemented group significantly differed for FokI genotype compared to other genotypes. This explained why certain women responded to treatment better than the others. When the frequencies of the genotypes of these five SNPs of the VDR gene were compared to other studies of different ethnicities, the results of this study were consistent with few studies but contradictory to others. The possible reasons for these differences could be because of small sample size and different ethnicities under study due to which the frequency of alleles and hence the genotypes differed.

Wing polyphenism is a type of phenotypic plasticity present in several insect species whereby a genotype have the ability to develop alternative wing morphs when exposed to different environmental cues. One organism demonstrating a clear case of wing polyphenism is the water strider species, Gerris buenoi, which develop long- or short wings depending on exposure to different photoperiods (the time the organism is exposed to light during a 24 h period). The molecular mechanism behind wing polyphenism in insects in general, and in water striders in particular, is largely unknown. From a study on wing polyphenism in the Brown planthopper (Nilaparvata lugens), some candidate genes have been identified and include two insulin receptor genes and the Forkhead transcription factor (FOXO). Since these genes have been demonstrated to affect wing polyphenism in Brown planthopper (BPH) and since G. buenoi contains an additional insulin receptor homolog, the potential role of these genes in regulating wing polyphenism in G. buenoi have in this project been investigated. The functional genetic technique RNA interference (RNAi) was used to evaluate the function of the genes. This method knock down gene expression in the genes mentioned above, one at a time, to investigate if they have a function in wing polyphenism in G. buenoi. DsRNA with specific homology to each target gene was successfully produced. However, when attempting to inject the dsRNA through micro injection all injected liquid leaked out from the body cavity, and the RNAi was therefore not successful. Further optimisation of the injection protocol has to be done to be able to perform RNAi properly in the future. Thereafter, RT-qPCR was used to evaluate whether the insulin receptor genes and FOXO are differentially expressed between the two photoperiods giving rise to the different wing morphs. The differential gene expression experiment showed differences between the mRNA levels of all target genes between G. buenoi being reared in the two different photoperiods. More specific upregulation of the genes FOXO and insulin receptor 2 in short winged G. buenoi were demonstrated. Further, insulin receptor 1-like, was also demonstrated to be upregulated in the short winged morph. Results presented in this project are in line with the previously identified regulation pattern in BPH, still the results need further evaluation. Since gene expression differences were present for all candidate genes between G. buenoi reared in the different photoperiods, theses genes could still be seen as potential candidate genes in wing polyphenism in water striders.

A administração de deidroepiandrosterona (DHEA) tem resultado em efeitos anti-diabetogênicos em animais de experimentação e no homem. Assim, o objetivo desse trabalho é avaliar o efeito do DHEA in vitro na expressão protéica do IR, do IRS-1, IRS-2, PI3-K, Akt, ERK-1/2; na expressão gênica do PDX-1, do PGC-1, da insulina, do GLUT-2 e da glicocinase; e avaliar a secreção estática de insulina de ilhotas pancreáticas de ratos. O cultivo das ilhotas por 24 horas com DHEA, não induziu nenhuma alteração tanto na expressão das proteínas quanto na secreção estática de insulina estimulada por glicose. Ocorreu aumento da fosforilação de ERK-1/2 e na expressão gênica do PGC-1. As células RINm5F, cultivadas por 72 horas com DHEA, apresentaram aumento da expressão total de IRS-1 e IRS-2. Concluímos, que 24 horas de cultura com ilhotas não é tempo suficiente para observar nenhuma alteração induzida pelo DHEA, na secreção de insulina, e na expressão das proteínas da via IRS/PI3-K/Akt. Células RINm5F podem ser um modelo alternativo para investigar os efeitos diretos do DHEA.
The dehydroepiandrosterone (DHEA) administration has resulted in reduction of abdominal fat and protection against insulin resistance from experimental animals and humans. So, the purpose of this project is measure the in vitro effects from DHEA: on protein expression of insulin receptor, the proteins IRS-1, IRS-2, PI3-K, Akt, and ERK-1/2; on gene expression of transcriptional factors PDX-1 and PGC-1, insulin, glucose transport GLUT-2 and glicocinase; and to measure the static insulin secretion, on cultured pancreatic islets of the rat. The culture of pancreatic islet for 24 hours with DHEA, did not induce nothing alteration on protein expression of the IR, IRS-1, IRS-2, PI3-K, Akt-1 and ERK-1/2, and static insulin secretion induced by glucose. However, happened increase ERK-1/2 phosphorylation and PGC-1 gene expression. The RINm5F cells, cultured by 72 hours, showed increase of the IRS-1 and IRS-2 expression. We conclude that 24 hours of the pancreatic islets culture are not sufficient time to look any alteration induced by DHEA, on insulin secretion, and on protein expression involved on IRS/PI3-K/Akt pathway. RINm5F cells can be an alternative model to research the direct effects from DHEA.

O hepatoblastoma é uma neoplasia embrionária hepática que ocorre na faixa pediátrica, rara, sendo bastante heterogênea devido aos seus diferentes componentes epiteliais e mesenquimais. Pouco ainda se sabe a respeito de sua patogênese. Utilizando um microscópio de captura a laser foram dissecadas áreas de componente epitelial do hepatoblastoma e áreas de tecido hepático adjacente não acometido. Destas amostras obtidas de pacientes não submetidos ao tratamento prévio, foram extraídos RNA e confeccionados cDNA microarrays, para análise comparativa da expressão gênica, seguida de validação por método imunohistoquímico de alguns genes selecionados. Comparando neoplasia e tecido hepático em duas amostras criopreservadas foram identificados 70 genes diferencialmente expressos, sendo 19 hiperexpressos e 51 hipoexpressos no tumor. A maioria dos genes encontrados foi mapeada nos cromossomos 1 e 2. Dos genes selecionados para validação por método imuno-histoquímico, destacaram-se o receptor de Insulina e o TFE3 (genes hipoexpressos no cDNA microarray). A imunomarcação para o receptor de insulina foi positiva tanto no tecido hepático não acometido quanto no componente epitelial fetal do hepatoblastoma , mas foi consistentemente negativa nas amostras de componente embrionário (9/9). A imunomarcação para o TFE3 foi positiva no tecido hepático não acometido, e nos componentes epitelial fetal e embrionário, em proporção variável das células com expressão mais intensa no componente embrionário. As reações imuno-histoquímicas para os outros genes selecionados não permitiram interpretação conclusiva. A alta proporção dos genes diferencialmente expressos localizados nos cromossomos 1 e 2 reflete os achados citogenéticos relatados na literatura relacionada ao hepatoblastoma . Achados de imunoexpressão de proteínas relacionadas aos genes TFE3 e receptor de insulina no tecido hepático e nos diferentes componentes do hepatoblastoma são inéditos e sugerem participação da via sinalizadora da insulina na patogênese destes tumores
Hepatoblastoma is a rare tumor, and little is known about its pathogenesis and genetic alterations. Using a laser capture microdissection microscope we sampled areas of epithelial component of hepatoblastoma prior chemotherapy and their normal liver counterpart in order to perform the comparative gene expression analysis followed by the validation of selected genes by immunohistochemistry. Comparing tumor and non-diseased liver in two frozen samples, 70 differentially expressed genes were found, 19 overexpressed and 51 underexpressed in the tumor. Most of the genes were located at chromosomes 1 and 2. Of the genes selected for validation by immunohistochemistry, the most interesting findings came from Insulin receptor and TFE3 (both underexpressed genes). Insulin receptor was positive in non diseased liver and in the fetal component of the Hepatoblastoma but was consistently negative in the embryonal component (9/9 cases). The TFE3 staining was positive in the normal liver and fetal and embryonal components of the tumor in variable proportion of the cells, more marked in the embryonal component. The higher proportion of genes located at chromosomes 1 and 2 corroborates the cytogenetics findings reported in the literature related to Hepatoblastoma . The immunohistochemistry findings of different expression of insulin receptor in the fetal and embryonal components of Hepatoblastoma and the positivity of TFE3 in normal liver and in the tumors epithelial components deserves further investigation regarding the role of these genes to the pathogenesis of Hepatoblastoma

Migraine is a common, debilitating neurovascular disease charactensed by severe recurrent headache, nausea and vomiting, photophobia and phonophobia. It is clinically diagnosed based on criteria specified by the International Headache Society (IHS), defining two major classes of migraine: migraine with aura (MA) and migraine without aura (MO) MA sufferers experience neurovascular disturbances that precede the headache phase of an attack. Although migraine is partly influenced by environmental determinants, there is a significant genetic component, with disease heritability estimated to be up to 60% and mode of transmission multifactorial. The disorder is common with a large Dutch study reporting lifetime prevalence estimates of 33% in women and 13.3% in men, with an earlier study estimating 24% of women and 12% of men in the overall population. Mutations in various ion channel genes are responsible for neuromuscular and other neurological disorders. Inherited ion channel mutations or 'channelopathies' are increasingly found to be the cause of various neurological disorders in humans. In familial hemiplegic migraine (FHM), a rare subtype of migraine with aura, mutations in the CACNA1A gene (localised at C19p13) have been fbund (FHM1). This gene codes for the alphalA subunit of the neuronal voltage-dependent P/Q-type calcium channel. Recently a second gene, ATP1A2 (FHM2) (localised at C1q23), was implicated in some EHM families. The ATP1A2 ion channel gene, codes for the alpha2 subunit of the Na+, K+ ion ATPase pump. These findings of mutations in these genes have focused attention on central nervous system ionic channels and helped to better understand EHM pathophysiology, where the best genetic evidence providing molecular insight into migraine still comes flom the mutations detected in the rare form of migraine with aura; FHM. Migraine family studies, at the Genomic Research Centre (GRC), have utilised linkage analysis methods in providing results that have indicated suggestive linkage to the FHM1-CACNA1A region on l9p13, in a large multigenerational family (Migraine Family 1; MEl) affected with typical migraine. Also linkage studies conducted within the GRC have implicated an additional susceptibility region on chromosome 1q31, but still not ruling out a second susceptibility region on C1q23, with the possibility of there being two distinct loci, on the chromosome lq region. The focus of research in this thesis is on two main chromosomal regions, which were tested for migraine susceptibility on chromosome 1 and chromosome 19. The research involved a cross-disciplinary approach utilising association, linkage and mutation screening approaches. Allelic candidate gene studies can provide a suitable method for locating genes of small effect that contribute to complex genetic disorders, such as migraine. Family linkage studies are useful for detection of chromosomal susceptibility regions and association studies are powerful when a plausible candidate gene and a sequence variant with potential functional relevance is examined. Mutation screening studies can indicate a direct cause of disorders such as migraine, where possible sequence variants may alter the translation of proteins in genes, causing the disease. The first gene exanted on chromosome 19 was that of the Low Density Lipoprotein Receptor (LDLR) gene. The LDLR gene is a cell surface receptor that plays an important role in cholesterol homeostasis. We investigated the (TA)n polymorphism in exon 18 of the LDLR gene on chromosome l9pl3.2 performing an association analysis in 244 typical migraine affected patients, 151 suffering from migraine with aura, 96 with migraine without aura and 244 unaffected controls. The populations consisted of Caucasians only and controls were age and sex matched. The results showed no significant difference between groups for allele frequency distributions of the (TA)n polymorphism even after separation of the migraine affected individuals into subgroups of MA and MO affected patients. This is in contradiction to Mochi et al, 2003 who found a positive association of this variant with MO. Our study discusses possible differences between the two studies and extends this research by investigating circulating cholesterol levels in a migraine affected genetically-isolated population. Another gene examined on chromosome l9pl3 was the insulin receptor gene (1NSR). The aim of this study was to investigate through direct sequencing the INSR gene in DNA samples from a migraine affected family previously showing linkage to chromosome l9pl3 in an attempt to detect disease associated mutations. The insulin receptor gene (INSR) on chromosome 19pl3.3-13.2 is a gene of interest since a number of SNPs located within the gene have been implicated in migraine with (MA) and without aura (MO). Six DNA samples obtained from non-founding migraine affected members of migraine family one (MF 1) were used in this study. Genomic DNA was sequenced for the 1NSR gene in exons 1-22 and the promoter region. In the six migraine family member samples, previously reported single nucleotide polymorphisms (SNP5) were detected within two exonic DNA coding regions of the INSR gene. These SNPs, in exon 13 and 17, do not alter the normal INSR polypeptide sequence. In addition, intron 7 also revealed a DNA base sequence variation. For the 5' untranslated promoter region of the gene, no mutations were detected. In conclusion, this study detected no INSR mutations in affected members of a chromosome 19 linked migraine pedigree. Hence, migraine linkage to this chromosomal region may involve other candidate genes. The NOTCH3 gene on C19p13.2-p13.l has previously been shown to be a gene involved in cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) and may also be implicated in migraine as there are some symptom similarities between the two disorders. The TNFSF7 gene localised on Cl9pl3 is homologous to the ligands of the TNF receptor family, including TNF-alpha and TNF-beta, genes that have both been previously associated with migraine. This study investigated the migraine susceptibility locus at Cl9p13 studying two genes that may be involved in the disorder. The NOTCH3 gene was analysed by sequencing all exons with known CADASIL mutations in a family (MF1) that has previously been shown to be linked to Cl9pl3. The sequencing results for affected members of this pedigree proved to be negative for all known sequence variants giving rise to mutation causing amino acid changes for CADASIL. The direct sequencing results displayed that of a normal coding sequence for the NOTCH3 gene F or the TNFSF7 gene, this was investigated through SNP association analysis using a matched case-control migraine diagnosed population. Chi-square results showed non-significant P values across all populations tested against controls except for the MO subgroup which displayed a weak association with the TNFSF7 SNP (genotype, allele analysis P = 0.036, P = 0 017 respectively). Our results suggest that common migraine is not caused by any known CADASIL mutations in the NOTCH3 gene of interest however, the TNFSF7 gene displayed signs of involvement in a MO affected population, but, further studies are needed to confirm these results and to further explore a TNF receptor - migraine potential interaction. A final examination on chromosome 19 involved a case report of an extremely rare and severe form of migraine. As stated earlier Familial Hemiplegic Migraine (FHM) is a severe rare sub-type of migraine and gene mutations on chromosome 19 have been identified in the calcium channel gene CACNA1A (Cl9pl3) fOr FHM. Recently a gene mutation (S218L) for a dramatic syndrome originating from FHM, commonly named 'migraine coma', has implicated exon 5 of the CACNA1A gene. The occurrence of trivial head trauma, in FHM patients, may also be complicated by severe, sometimes even fatal, cerebral edema and coma occurring after a lucid interval. Hemiplegic migraine has also been found to be sporadic in which both forms share a similar spectrum of clinical presentations and genetic heterogeneity. The case report presented in this study enhances the involvement of the S218L CACNA1A mutation in the extremely rare disorder of minor head trauma induced migraine coma. It not only proves to be a powerful diagnostic tool in detecting cases of FHM head trauma induced coma but also for sporadic hemiplegic migraine (SHM) coma subjects. We conclude from this case study that the S218L mutation, in the CACNA1A calcium channel subunit gene, is involved in sporadic hemiplegic migraine (SHM), delayed cerebral edema and coma after minor head trauma. This thesis also involved analysis of chromosome 1 for migraine susceptibility, where FHM studies provided a foundation fOr common migraine research on chromosome 1. Studies have suggested that mutations in the CACNA1A gene on chromosome l9p cause FHM in only approximately 50% of affected pedigrees. The CACNAIA gene has previously been tested, within the Genomics Research Centre, in the common forms of migraine; however no new mutations or the FHM mutations were detected in these MA/MO affected samples. A second FHM susceptibility locus maps to chromosome 1q23 and mutations in the ATP1A2 gene have recently been implicated in two Cl-linked FHM pedigrees. As FHM is considered a rare and severe form of MA, it is possible that the chromosome 1q23 locus, and the ATP1A2 gene, may be involved in the common forms of migraine with (MA) and possibly without aura (MO). Also, we have previously reported evidence of linkage to microsatellite markers on chromosome 1q31 in a large pedigree affected predominately with MA, which suggests the possibility that there are two distinct loci for migraine susceptibility on chromosome 1. The objectives of this study were to extend our linkage analysis of chromosome lq microsatellite markers in predominantly migraine with aura pedigrees. Also, our aim was to test the novel FHM-2 ATP1A2 gene for involvement in these migraine affected pedigrees and a previous pedigree (Migraine Family 14; MF 14) showing evidence of linkage of markers to Clq31. This was performed by a chromosome 1 scan (31 markers) in 21 multiplex pedigrees affected mainly with MA. Also, the known FHM-2 ATP1A2 gene mutations were tested, by sequencing, fOr involvement in MA and MO in these pedigrees. Mutation screening by direct sequencing was also performed throughout the coding areas of the ATP1A2 gene in 3 MA individuals fiom MF14. The results of this study detected evidence for linkage in our migraine pedigrees at chromosome 1q23, to microsatellite markers spanning the ATP1A2 (FHM-2) gene. However testing of the known ATP1A2 gene mutations (for FHM) in migraine probands of pedigrees showing excess allele sharing was negative, with no mutations detected in these migraineurs. Sequencing of the entire coding areas of the gene through 3 MA affecteds from MF14, a pedigree showing significant linkage to this region, was also negative for mutations. In conclusion, this study reported that microsatellite markers on chromosome 1q23 show evidence of excess allele sharing in MA and some MO pedigrees, suggesting linkage to the common forms of migraine and the presence of a susceptibility gene in this region. The new FHM-2 (ATPIA2 gene) mutations reported by Fusco et al, 2003 do not cause migraine in probands of affected pedigrees showing excess allele sharing to markers in this genomic region. Also no mutations were detected in all exons of the ATP1A2 gene in 3 MA affected individuals from a large pedigree (MF14) showing linkage to this region. Investigation in this thesis continued on chromosome 1, with other genes being examined on C1q23, as well as the C1q31 region for a migraine susceptibility locus or gene. Previously in our laboratory, evidence for linkage was shown to migraine at C1q31 in one family predominantly affected with MA, with microsatellite markers in this region. The initial Cl study (above; ATP1A2 gene) has also provided evidence for linkage to the chromosome 1 locus 1q23, with evidence for excess allele sharing of markers in predominantly MA affected pedigrees. To further investigate both chromosome I loci, an investigation with six candidate genes that lie within the C1q23 and 1q31 regions through association analysis was undertaken. The results from this study reported non-significant chi-square results, showing P values greater than 0.05 across all SNPs (and a CA rpt) tested. An exception was the rs704326 SNP from exon 43 of the CACNA1E gene on C1q31. P values significantly less than 0.001 were obtained in the total migraine population and the MA subgroup, with similar frequency comparisons ascertained in both genotype and allele analysis. Examination through contingency table analysis of the CACNA1E flequency data indicated that the risk allele (A) was over-represented in the migraine group compared to the control group. Further comparison of the genotype data indicated a difference in frequency distributions (P less than 0 0001). Stratified analyses of migraine subtypes indicated that this association was specifically attributed to the MA subtype group. Odds ratios produced an OR of 4.14 with a 95% CI of 2.36 - 7.26 (P less than 0.0001). The positive association results obtained within the CACNA1E gene are interesting in the fact that FHM is considered to be a rare and severe form of migraine with aura (MA) and FHM-1 is caused by mutations contained within the calcium channel gene CACNA1A (localized at Cl9p13). The idea that FHM and specifically an FHM gene in the C1q31 genomic region may also contribute to susceptibility to the more common forms of migraine i e. migraine with aura, strongly supports and reinforces the idea that a common defective gene may be influencing both FHM and typical migraine. In conclusion, this thesis undertook a cross-disciplinary approach to genetic research of a complex disorder. The research involved linkage, association and mutation analysis strategies of migraine. This research implicated a specific variant on chromosome 1 and further supported the heterogeneic nature of migraine. Future directions into migraine research should involve further investigation of this specific variant and this genomic region. Such studies may aid in the development of more precise diagnosis and treatment methods for this complex disorder.

Migraine is a common, debilitating neurovascular disease charactensed by severe recurrent headache, nausea and vomiting, photophobia and phonophobia. It is clinically diagnosed based on criteria specified by the International Headache Society (IHS), defining two major classes of migraine: migraine with aura (MA) and migraine without aura (MO) MA sufferers experience neurovascular disturbances that precede the headache phase of an attack. Although migraine is partly influenced by environmental determinants, there is a significant genetic component, with disease heritability estimated to be up to 60% and mode of transmission multifactorial. The disorder is common with a large Dutch study reporting lifetime prevalence estimates of 33% in women and 13.3% in men, with an earlier study estimating 24% of women and 12% of men in the overall population. Mutations in various ion channel genes are responsible for neuromuscular and other neurological disorders. Inherited ion channel mutations or 'channelopathies' are increasingly found to be the cause of various neurological disorders in humans. In familial hemiplegic migraine (FHM), a rare subtype of migraine with aura, mutations in the CACNA1A gene (localised at C19p13) have been fbund (FHM1). This gene codes for the alphalA subunit of the neuronal voltage-dependent P/Q-type calcium channel. Recently a second gene, ATP1A2 (FHM2) (localised at C1q23), was implicated in some EHM families. The ATP1A2 ion channel gene, codes for the alpha2 subunit of the Na+, K+ ion ATPase pump. These findings of mutations in these genes have focused attention on central nervous system ionic channels and helped to better understand EHM pathophysiology, where the best genetic evidence providing molecular insight into migraine still comes flom the mutations detected in the rare form of migraine with aura; FHM. Migraine family studies, at the Genomic Research Centre (GRC), have utilised linkage analysis methods in providing results that have indicated suggestive linkage to the FHM1-CACNA1A region on l9p13, in a large multigenerational family (Migraine Family 1; MEl) affected with typical migraine. Also linkage studies conducted within the GRC have implicated an additional susceptibility region on chromosome 1q31, but still not ruling out a second susceptibility region on C1q23, with the possibility of there being two distinct loci, on the chromosome lq region. The focus of research in this thesis is on two main chromosomal regions, which were tested for migraine susceptibility on chromosome 1 and chromosome 19. The research involved a cross-disciplinary approach utilising association, linkage and mutation screening approaches. This research implicated a specific variant on chromosome 1 and further supported the heterogeneic nature of migraine. Future directions into migraine research should involve further investigation of this specific variant and this genomic region. Such studies may aid in the development of more precise diagnosis and treatment methods for this complex disorder.
Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Medical Science
Full Text

GH and the insulin like growth factor type I (IGF-I) have synergistic functions on protein synthesis and muscle mass. In adipose tissue, GH stimulates lipolysis and lipid oxidation, while IGF-I stimulates the differentiation of pre adipocytes to adipocytes. In glucose metabolism , GH and IGF-I have antagonist opposite actions, been GH antagonist and IGF-I synergetic to insulin sensitivity (IS). Heterozygous adults individuals for the mutation c.104 = 1G> A in the GH releasing hormone receptor gene (MUT/N), present a mild reduction of GH and normal IGF-I levels accompanied by a significant reduction in lean body mass (Kg), with a tendancy of reduction in fat mass (kg), compared to homozygous normal adults individuals (N/N). IS and the beta cell function are unknown in individuals MUT/ N. To evaluate them, it was performed the oral glucose tolerance test with administration of 75g of glucose and serum glucose and insulin were measured at 0, 30, 60, 90, 120 and 180 minutes in 25 individual MUT/ N (12 M / 13 F, 40.08 ± 10.87 years) and 25 N/N (14 M / F 11; 39.96 ± 12.49 years). There was no difference in height, nevertheless weight, BMI, waist and hip circunferences were lower in individuals MUT/N. IS was assessed by HOMAir, where lower values indicate a greater IS and the QUICKI, OGIS 2 and OGIS 3, where higher values indicate higher SI. The beta cell function was assessed by HOMA-beta, insulinogenic index and area under the curve of insulin / glucose ratio (ASC I/G). ANOVA showed no difference between glucose and insulin responses between the groups. The areas under the curve of glucose and insulin were also similar between the number of patients with pre diabetes and diabetes. No changes were observed in the HOMAir, QUICKI, OGIS 2 and OGIS 3, HOMA beta, insulinogenic index and ASC I/G between the two groups. In conclusion, insulin sensitivity and beta cell function in MUT/N individuals are similar to MUT/N individuals.
GH e o fator de crescimento semelhante à insulina tipo I (IGF-I) apresentam funções sinérgicas sobre a síntese protéica e massa muscular. No tecido adiposo, o GH estimula a lipólise e oxidação lípidica, enquanto o IGF-I estimula a diferenciação dos pré adipócitos em adipócitos. No metabolismo glicídico, GH e IGF-I têm ações opostas, sendo o GH antagônico e o IGF-I sinérgico à sensibilidade insulínica (SI). Indivíduos heterozigóticos adultos para a mutação c.104=1G>A gene do receptor do hormônio liberador do GH (MUT/N) no, apresentam discreta redução do GH e níveis normais de IGF-I acompanhada de redução significativa da massa magra (Kg), com tendência à redução da massa gorda (Kg), em relação aos indivíduos homozigóticos normais (N/N). A SI e a função das células beta são desconhecidas nos indivíduos MUT/N. Para avaliá-las, foi realizado o teste de tolerância oral à glicose com administração de 75g de glicose e dosagens de glicose e insulina nos tempos 0, 30, 60, 90, 120 e 180 minutos em 25 indivíduos MUT/N (12 M/ 13 F; 40,08 ± 10,87 anos) e 25 N/N (14 M/ 11 F; 39,96 ± 12,49 anos). Não houve diferença na altura, contudo o peso, o IMC, a cintura e o quadril foram menores nos indivíduos MUT/N. A sensibilidade à insulina (SI) foi avaliada pelo HOMAir, onde menores valores, indicam maior SI e pelos QUICKI, OGIS 2 e OGIS 3, onde maiores valores, indicam maior SI. A função da célula beta foi avaliada pelo HOMA-beta, índice insulinogênico e área sob a curva da razão insulina/ glicose (ASC I/G). ANOVA indicou que não houve diferença entre as respostas glicêmica e insulinêmica entre os grupos. As áreas sob a curva de glicose e insulina foram semelhantes como também entre o número de pacientes com pré diabetes e diabetes. Não foram verificadas variações no HOMAir, QUICK, OGIS 2 e OGIS 3, HOMA beta, índice insulinogênico e ASC I/G entre os dois grupos. Em conclusão, a sensibilidade insulínica e a função de célula beta nos indivíduos MUT/N são semelhantes a dos indivíduos N/N.

Crianças nascidas pequenas para a idade gestacional (PIG) apresentam maior risco de permanecerem com baixa estatura na vida adulta. Os fatores de crescimento insulina-símile 1 e 2 (IGF-1 e IGF-2) são os principais fatores endócrinos determinantes do crescimento fetal. Na vida pós-natal o GH, principal hormônio promotor de crescimento, exerce a maior parte de seus efeitos por meio do IGF-1. A grande maioria das ações conhecidas do IGF-1 e IGF-2 são mediadas via receptor tirosina quinase conhecido como receptor tipo 1 de IGFs (IGF-1R). Os objetivos deste trabalho foram estudar os genes IGF1 e IGF1R em crianças nascidas pequenas para a idade gestacional que não recuperaram o crescimento na vida pós-natal. Foram selecionados 145 pacientes nascidos PIG, 72 sem catch up e 73 com catch up. Em 54 PIG sem catch up foi estudado toda a seqüência codificadora do gene IGF1 por meio de PCR e seqüenciamento direto, nos demais PIG sem catch up e nos 73 PIG com catch up foi estudado apenas o exon 6 do IGF-1 por PCR e seqüenciamento direto para avaliação de um polimorfismo encontrado nesta região. Nos pacientes que apresentavam concentração sérica de IGF-1 e IGFBP-3 acima da média para idade e sexo e seqüência do IGF1 normal (n=23) foi realizada coleta de sangue periférico com posterior separação de leucócitos mononucleares pelo gradiente de ficoll seguido por extração de RNA pelo método de Trizol® Posteriormente, a partir do RNA, sintetizamos o cDNA (DNA complementar) utilizando primers randômicos. Foi realizado PCR e seqüenciamento direto do cDNA, além de análise da expressão do IGF1R por PCR em tempo real. Nenhuma mutação foi encontrada no gene IGF1. Entretanto um locus altamente polimórfico foi encontrada na região 3\' não traduzida do exon 6 deste gene, região esta envolvida no processo de poliadenilação. A freqüência das variantes alélicas foi semelhante em PIG com e sem catch-up e em controles nascidos AIG. Analisando o fenótipo de pacientes PIG que apresentavam a variante alélica wild type ou uma das três variantes alélicas mais freqüentemente encontradas, não observamos diferenças significativas entre peso e comprimento ao nascimento, níveis de IGF-1 e crescimento na vida pós-natal. No gene IGF1R encontramos duas variantes alélicas nunca descritas previamente. A primeira variante encontrada está localizada no exon 1, em uma região de peptídeo sinal do pro IGF-1R e consiste na troca do nucleotídeo guanina pelo nucleotídeo adenina na posição 16 da região codificadora (c.16G>A), levando a troca do aminoácido glicina por arginina na posição 6 da proteína (p.G6R). A outra mutação encontrada está localizada no exon 7 onde observamos uma troca do nucleotídeo citosina por timina na posição 1531 do cDNA (c.1531 C>T), levando a uma troca de arginina por triptofano na posição 511 do IGF1R (p.R511W). Adicionalmente, foi observada uma expressão do IGF1R diminuída em 5 pacientes estudados.Concluímos que as variantes alélicas encontradas na região de poliadenilação do IGF1 não influenciam significativamente as características ao nascimento e pós-natais de crianças nascidas PIG ou a altura adulta de indivíduos normais nascidos AIG. O estudo do IGF1R identificou duas novas variantes alélicas em heterozigose no gene IGF1R e, em cinco pacientes, observamos uma expressão reduzida deste gene. Pacientes com alterações no gene IGF1R não apresentam um fenótipo característico que os diferencie de outras crianças nascidas PIG sem alterações neste gene, mostrando a importância dos estudos moleculares.
Children born small for gestational age (SGA) have a higher risk of remaining short in adulthood. The insulin-like growth factors 1 and 2 (IGF-1 and IGF-2) are the main factors determining endocrine fetal growth. GH is the main promoter of linear growth in the postnatal life, exerting its effects mostly through the IGF-1. The vast majority of known actions of IGF-1 and IGF-2 are mediated by the insulin-like growth factor type 1 receptor (IGF-1R), a member of the tyrosine kinase receptors family. The aim of this study was to investigate IGF1 and IGF1R genes mutations in children born small for gestational age without catch up growth in postnatal life. We selected 145 patients born SGA, 72 without catch-up and 73 with catch up. The whole coding region of the IGF1 gene was sequenced in 54 patients without catchup. In the other SGA children without catch-up and in 73 SGA with catch-up, only the exon 6 of IGF1 was sequenced to assess the influence of allelic variants present in this region. In patients with normal IGF1 sequence and IGF-1 and IGFBP-3 serum levels above the mean for age and sex (n = 23) total RNA was extracted from peripheral blood lymphocytes followed by cDNA synthesis with random primers. The IGF1R cDNA was amplified using specific primers followed by direct sequencing. IGF1R expression was analyzed by real-time PCR. No mutations were found in the IGF1 gene. However a highly polymorphic sequence was identified in the upstream core polyadenylation signal (UCPAS) located in IGF1 3\' UTR at exon 6. The frequency of the identified allelic variants was similar in SGA children with and without catch-up and in controls. Furthermore, children homozygous for the wild-type allele and those carrying the allelic variants in homozygous or heterozygous state presented similar weight and length at birth, as well as serum IGF-1 levels and postnatal growth features. Two novel nonconservative allelic variants were identified in IGF1R in 23 SGA children (8.7%) in the heterozygous state. The first variant (c.16G>A) was located in the exon one, leading to a substitution of glicine by arginine in the pro-IGF-1R signaling peptide (p.G6R). The second variant was located in exon 7 (c.1531 C>T), leading to a substitution of arginine by tryptophan in the amino acid 511 of the IGF1-R (p.R511W). Moreover, a decreased IGF1R expression was observed in 5 of the 23 patients with elevated serum IGF-1 concentrations. We conclude that the UCPAS allelic variants did not significantly influence the birth and postnatal characteristics of children born SGA, neither the adult height of normal individuals born adequate for gestational age. The IGF1R study identified two novel allelic variants in two patients and a reduced expression of the IGF1R was observed in five patients. Patients with alterations in IGF1R did not have a distinctive phenotype when compared with other children born SGA without changes in this gene, indicating the importance of molecular studies.

Introdução: Os glicocorticoides (GCs) estão envolvidos na regulação e adaptação da resposta ao estresse, exercendo seus efeitos através de seus receptores. Variações polimórficas no gene do receptor de glicocorticoide (GR) têm sido caracterizadas funcionalmente. O polimorfismo A3669G do gene do GR está relacionado a modificações na sensibilidade aos GCs e mudanças no perfil metabólico. Concentrações fisiológicas de GCs estimulam a ingestão calórica e, na presença de insulina, modificam a preferência alimentar. A variante A3669G do gene do GR parece levar a um menor risco para diabetes, em pacientes com Síndrome de Cushing, e para o tabagismo, quando associado a um polimorfismo do gene do receptor de mineralocorticoide, sugerindo uma modulação na via de recompensa. O objetivo deste trabalho é avaliar a associação de variantes do polimorfismo A3669G do gene do GR com o comportamento alimentar e parâmetros metabólicos em uma amostra de estudantes, correlacionando com dados de neuroimagem funcional. Métodos: A amostra provém de alunos de 6 escolas de Porto Alegre, avaliados em 2008 e em 2013. Em 2008, 131 indivíduos apresentavam o protocolo completo de avaliação e, destes, 74 retornaram em 2013. A avaliação incluiu genotipagem, antropometria, exames laboratoriais, comportamento alimentar e um paradigma avaliando a ativação cerebral em resposta a visualização de imagens de alimentos palatáveis, não palatáveis e de objetos neutros. A análise da associação com os fenótipos foi realizada através do teste t de Student e Chi quadrado; os dados do estudo longitudinal foram analisados por meio de Equações de Estimatição Generalizada. Resultados: A variante G do polimorfismo A3669G do gene do GR foi encontrado em 17,6% em 2008 e em 14,9% da amostra em 2013. Não houve diferença entre os grupos de carreadores do alelo G e não carreadores quanto a diferentes confundidores; a comparação entre as médias dos dois grupos sobre o consumo calórico proveniente de proteínas, carboidratos e gorduras em 2008 não revelou diferenças significativas; nesta etapa, as análises evidenciaram maior consumo de açúcares e de calorias totais no grupo não carreador do alelo G. Em 2013, estes indivíduos não carreadores do alelo G do polimorfismo A3669G apresentaram maior insulinemia e além de aumento no índice de resistência à insulina, sem diferenças no consumo alimentar. Os dados de neuroimagem funcional indicaram que a visualização de imagens de alimentos palatáveis pelo grupo não carreador do alelo G ativou o giro occipital médio, uma região implicada no processamento visual, mostrando menor ativação em giro pré central e nas áreas de Brodmann 4 e 6, relacionadas ao planejamento motor e sensibilidade ao sabor. Conclusão: Os resultados mostram que os indivíduos não carreadores da variante G do polimorfismo A3669G do gene do GR apresentaram menor sensibilidade à insulina, precedidos pela modulação na preferência alimentar. Os achados em neuroimagem funcional indicam maior saliência de incentivo aos alimentos palatáveis e predisposição à impulsividade no grupo não carreador do alelo G. Sugere-se que a redução na sensibilidade em nível celular aos GCs relacionada à presença do alelo G, afete a ingestão alimentar, reduzindo o consumo de alimentos palatáveis, diminuindo o risco para doenças metabólicas.
Introduction: Glucocorticoids are involved in regulation and adaptation of the stress response, exerting effects through its receptors. Variations on the glucocorticoid receptors genes have been characterized functionally. The A3669G polymorphism of the glucocorticoid receptor gene is related to a change in the tissue sensitivity to glucocorticoids and altered metabolic profile. Physiological concentrations of glucocorticoids stimulate food intake and in the presence of insulin affect food preferences. The G variant of the A3669G polymorphism appears to lead to a lower risk for diabetes, in patients with Cushing's syndrome, and smoking, when associated with a polymorphism of the mineralocorticoid receptor gene, suggesting a modulation in reward pathways. The objective of this study is to evaluate the association of A3669G polymorphism variants with feeding behavior and metabolic parameters in a sample of students correlating with functional neuroimaging data. Methods: The sample includes students of 6 schools in Porto Alegre, evaluated at two occasions 2008 and in 2013. In 2008, 131 individuals had complete protocol assessment and, from these, 74 returned in for re- evaluation in 2013. The evaluation included genotyping, anthropometry, laboratory tests, feeding behavior and a functional MRI paradigm to verify brain activation in response to the visualization of palatable, non- palatable foods and neutral items. The association with phenotypes was performed using Student's t test and Chi-square; longitudinal study data were evaluated using Generalized Estimating Equations. Results: The variant of the A3669G polymorphism was found in 17.6% of the students in 2008 and 14.9% of the sample in 2013. There was no difference between groups in the sample composition; the comparison between groups of the mean caloric intake originating from proteins, carbohydrates and fats in 2008 revealed no significant differences; at this time, analysis showed lower consumption of sugars and total calories in the G carrier group. In 2013, these individuals showed a reduction in insulin level and resistance, with no differences in food intake. The fMRI data indicated that viewing a food palatable image by the wild-type allele carrier group activated a region involved in visual processing (middle occipital gyrus) and deactivated an area related to motor planning and sensitivity to taste (pre central gyrus). Conclusion: The results showed that G carriers of the A3669G polymorphism of glucocorticoid receptor gene had lower insulin resistance levels, preceded by modulation of their food preference. The findings in functional neuroimaging showed increased incentive salience on viewing palatable food images and a predisposition for impulsivity in noncarriers. Data suggest that reduction in glucocorticoids sensitivity at a cellular level affects food intake, by reducing consumption of palatable foods, possibly decreasing the risk for metabolic diseases.

Members of the insulin-like growth factor (IGF) family have been shown to play critical roles in normal growth and development, as well as in tumour biology. The IGF system is complex and the biological effects of the IGFs are determined by their diverse interactions between many molecules, including their interactions with extracellular matrix (ECM) proteins. Recent studies have demonstrated that IGFs associate with the ECM protein vitronectin (VN) through IGF-binding proteins (IGFBP) and that this interaction modulates IGF-stimulated biological functions, namely cell migration and cell survival through the cooperative involvement of the type-I IGF receptor (IGF-1R) and VN-binding integrins. Since IGFs play important roles in the transformation and progression of breast cancer and VN has been found to be over-expressed at the leading edge of breast tumours, this project aimed to describe the effects of IGF-I:VN interactions on breast cell function. This was undertaken to dissect the molecular mechanisms underlying IGF-I:VN-induced responses and to design inhibitors to block the effects of such interactions. The studies described herein demonstrate that the increase in migration of MCF-7 breast cancer cells in response to the IGF-I:IGFBP-5:VN complex is accompanied by differential expression of genes known to be involved in migration, invasion and/or survival, including Tissue-factor (TF), Stratifin (SFN), Ephrin-B2, Sharp-2 and PAI-1. This „migration gene signature‟ was confirmed using real-time PCR analysis. Substitution of the native IGF-I within the IGF-I:IGFBP:VN complex with the IGF-I analogue, \[L24]\[A31]-IGF-I, which has a reduced affinity for the IGF-1R, failed to stimulate cell migration and interestingly, also failed to induce the differential gene expression. This supports the involvement of the IGF-1R in mediating these changes in gene expression. Furthermore, lentiviral shRNA-mediated stable knockdown of TF and SFN completely abrogated the increased cell migration induced by IGF-I:IGFBP:VN complexes in MCF-7 cells. Indeed, when these cells were grown in 3D Matrigel™ cultures a decrease in the overall size of the 3D spheroids in response to the IGF-I:IGFBP:VN complexes was observed compared to the parental MCF-7 cells. This suggests that TF and SFN have a role in complex-stimulated cell survival. Moreover, signalling studies performed on cells with the reduced expression of either TF or SFN had a decreased IGF-1R activation, suggesting the involvement of signalling pathways downstream of IGF-1R in TF- and/or SFN-mediated cell migration and cell survival. Taken together, these studies provide evidence for a common mechanism activated downstream of the IGF-1R that induces the expression of the „migration gene signature‟ in response to the IGF-I:IGFBP:VN complex that confers breast cancer cells the propensity to migrate and survive. Given the functional significance of the interdependence of ECM and growth factor (GF) interactions in stimulating processes key to breast cancer progression, this project aimed at developing strategies to prevent such growth factor:ECM interactions in an effort to inhibit the downstream functional effects. This may result in the reduction in the levels of ECM-bound IGF-I present in close proximity to the cells, thereby leading to a reduction in the stimulation of IGF-1R present on the cell surface. Indeed, the inhibition of IGF-I-mediated effects through the disruption of its association with ECM would not alter the physiological levels of IGF-I and potentially only exert effects in situations where abnormal over expression of ECM proteins are found; namely carcinomas and hyperproliferative diseases. In summary, this PhD project has identified novel, innovative and realistic strategies that can be used in vitro to inhibit the functions exerted by the IGF-I:IGFBP:VN multiprotein complexes critical for cancer progression, with a potential to be translated into in vivo investigations. Furthermore, TF and SFN were found to mediate IGF-I:IGFBP:VN-induced effects, thereby revealing their potential to be used as therapeutic targets or as predictive biomarkers for the efficacy of IGF-1R targeting therapies in breast cancer patients. In addition to its therapeutic and clinical scope, this PhD project has significantly contributed to the understanding of the role of the IGF system in breast tumour biology by providing valuable new information on the mechanistic events underpinning IGF-I:VN-mediated effects on breast cell functions. Furthermore, this is the first instance where favourable binding sites for IGF-II, IGFBP-3 and IGFBP-5 on VN have been identified. Taken together, this study has functionally characterised the interactions between IGF-I and VN and through innovative strategies has provided a platform for the development of novel therapies targeting these interactions and their downstream effects.

Introdução: A patogênese molecular dos tumores adrenocorticais é heterogênea e ainda pouco compreendida. A hiperexpressão do gene do fator de crescimento semelhante à insulina II (IGF-II) tem sido demonstrada na maioria dos carcinomas adrenocorticais em adultos. Os efeitos mitogênicos do IGF-II são mediados pela interação com o receptor de IGF-I (IGF-IR). Adicionalmente, o fator esteroidogênico 1 (SF-1) e o fator codificado por uma região crítica do cromossomo X associada ao sexo reverso e à hipoplasia adrenal congênita (DAX-1), ambos envolvidos no desenvolvimento e na esteroidogênese adrenal, também têm sido implicados na tumorigênese adrenocortical. Objetivos: Analisar a expressão gênica e a imunorreatividade dos fatores IGF-II, IGF-IR, SF-1 e DAX-1 em tumores adrenocorticais de crianças e adultos. Avaliamos ainda os efeitos de um inibidor seletivo do IGF-IR (NVP-AEW541) na proliferação celular e apoptose de linhagens celulares de tumores adrenocorticais. Métodos: Neste estudo, a expressão gênica foi determinada por PCR quantitativa em tempo real em 57 tumores adrenocorticais (37 adenomas e 20 carcinomas). Vinte e três pacientes tinham idade inferior ou igual a 15 anos. A análise de imunohistoquímica foi realizada em 109 tumores adrenocorticais (71 adenomas e 38 carcinomas). Os efeitos do tratamento com NVP-AEW541 (0,3 a 30 M) na proliferação celular e apoptose foram avaliados nas células NCI H295 de carcinoma adrenocortical humano e em uma nova linhagem celular estabelecida a partir de um adenoma adrenocortical pediátrico da nossa casuística. Resultados: A hiperexpressão do gene IGF-II foi evidenciada nos tumores adrenocorticais benignos e malignos de crianças (média ± EPM, 50,8 ± 18,5 vs. 31,2 ± 3,7, respectivamente; p= 0,23). Em adultos, a expressão do gene IGF-II foi significativamente mais elevada nos carcinomas adrenocorticais quando comparada com os adenomas (270,5 ± 130,2 vs. 16,1 ± 13,3; p= 0,0001). O percentual das células neoplásicas imunorreativas para o IGF-II não foi significativamente diferente entre os adenomas e carcinomas adrenocorticais pediátricos (14,1 ± 2,8% vs. 31,1 ± 13,1%, respectivamente; p= 0,32). Em adultos, o percentual das células neoplásicas positivas para o IGF-II foi significativamente maior nos carcinomas adrenocorticais em relação aos adenomas (34,4 ± 5,8% vs. 14,2 ± 3,2, respectivamente; p= 0,03). Os valores de RNAm do IGF-IR foram significativamente mais elevados nos carcinomas adrenocorticais pediátricos em relação aos adenomas (9,1 ± 1,2 vs. 2,6 ± 0,3; p= 0,0001), enquanto a expressão deste receptor foi similar nos tumores adrenocorticais benignos e malignos de adultos (1,6 ± 0,3 vs. 1,8 ± 0,5, respectivamente; p= 0,75). Os valores de RNAm do IGF-IR [risco relativo (RR) 2,0, intervalo de confiança (IC) de 95% 1,2 a 3,1; p= 0,004] e os critérios histopatológicos de Weiss (RR 1,8, IC de 95% 1,2 a 2,7; p= 0,003) foram marcadores independentes de metástases em crianças e adultos, respectivamente. O NVP-AEW541 inibiu a proliferação celular estimulada por IGF-II de forma dose e tempo dependentes nas 2 linhagens celulares de tumores adrenocorticais através de uma significativa indução da apoptose. Adicionalmente, a hiperexpressão do gene SF-1 foi identificada em 13% e 15% dos tumores adrenocorticais diagnosticados em crianças e adultos, respectivamente. O percentual das células neoplásicas com imunorreatividade nuclear para SF-1 foi significativamente maior nos tumores adrenocorticais pediátricos em relação aos tumores diagnosticados em adultos (29,1 ± 5,4% vs. 8,3 ± 2,3%, respectivamente; p= 0,0001). Estes dados indicam que o aumento da expressão do SF-1 nos tumores adrenocorticais pediátricos ocorre em nível pós-traducional. A hiperexpressão do gene DAX-1 foi identificada em 39% dos tumores adrenocorticais, com uma prevalência semelhante em crianças e adultos. De forma similar, o aumento da expressão da proteína DAX-1 foi identificado em 36% e 27% dos tumores adrenocorticais diagnosticados em crianças e adultos, respectivamente. A imunorreatividade nuclear para DAX- 1 foi semelhante nos adenomas e carcinomas adrenocorticais (29,2 ± 3,8% vs. 21,4 ± 5,8% das células neoplásicas, respectivamente; p= 0,12). Conclusões: A hiperexpressão do IGF-II tem um papel relevante na tumorigênese adrenocortical. A hiperexpressão do gene IGF-IR foi um marcador biológico independente do carcinoma adrenocortical metastático em crianças. Os efeitos anti-tumorais in vitro do NVP-AEW541 sugerem que o IGF-IR constitui um potencial alvo terapêutico para o carcinoma adrenocortical humano. Adicionalmente, o aumento da expressão do SF-1 foi evidenciado predominantemente nos tumores adrenocorticais pediátricos. A hiperexpressão do DAX-1 constitui um evento importante na patogênese molecular dos tumores adrenocorticais benignos e malignos
Introduction: The molecular pathogenesis of adrenocortical tumors is heterogeneous and incompletely understood. Insulin-like growth factor II (IGF-II) overexpression has been demonstrated in adult adrenocortical carcinomas. IGF-II exerts its mitogenic effects through interaction with IGF-I receptor (IGF-IR). In addition, steroidogenic factor 1 gene (SF-1) and dosage-sensitive sex reversal-adrenal hypoplasia congenita critical region on the X chromosome gene (DAX-1), which regulate adrenal development and steroidogenesis, have been also involved in adrenocortical tumorigenesis. Objectives: To analyze gene and protein expression of IGF-II, IGF-IR, SF-1 and DAX-1 in pediatric and adult adrenocortical tumors. We also evaluated the effects of a selective IGF-IR kinase inhibitor (NVP-AEW541) on adrenocortical tumor cell lines. Methods: Gene expression was determined by quantitative real-time PCR in 57 adrenocortical tumors (37 adenomas and 20 carcinomas) from 23 children and 34 adults. Twenty and three patients were younger than 15 years. A tissue microarray analysis was performed on a large cohort of 109 ACT (71 adenomas and 38 carcinomas; 39 children and 70 adults) In addition, the effects of NVP-AEW541 treatment (0.3 to 30M) on proliferation and apoptosis were investigated in the NCI H295 cell line and in a new cell line established from a pediatric adrenocortical adenoma of our cohort. Results: IGF-II transcripts were overexpressed in pediatric adrenocortical carcinomas and adenomas (mean ± SE, 50.8 ± 18.5 vs. 31.2 ± 3.7, respectively; p= 0.23). IGF-II gene expression was significantly higher in adult adrenocortical carcinomas than in adenomas (270.5 ± 130.2 vs. 16.1 ± 13.3; p= 0.0001). The percentual of neoplastic cells immunostaining for IGF-II was not statistically different between pediatric adrenocortical adenomas and carcinomas (14.1 ± 2.8% vs. 31.1 ± 13.1%, respectively; p= 0.32). Otherwise, the percentual of positive neoplastic cells for IGF-II was significantly higher in adult adrenocortical carcinomas than in adenomas (34.4 ± 5.8% vs. 14.2 ± 3.2, respectively; p= 0.03). IGF-IR mRNA levels were significantly higher in pediatric adrenocortical carcinomas than in adenomas (9.1 ± 1.2 vs. 2.6 ± 0.3; p= 0.0001), whereas similar IGF-IR expression levels were identified in adult adrenocortical carcinomas and adenomas (1.6 ± 0.3 vs. 1.8 ± 0.5, respectively; p= 0.75). In a Cox multivariate analysis, IGF-IR gene expression [hazard ratio (HR) 2.0, 95% confidence interval (CI) 1.2 to 3.1; p= 0.004] and Weiss score (HR 1.7, 95% CI 1.2 to 2.7; p= 0.003) were independent biomarkers of metastasis in pediatric and adult adrenocortical tumors, respectively. Furthermore, NVP-AEW541 blocked cell proliferation in a dose- and time-dependent manner in both NCI H295 and pediatric adrenocortical cell lines through a significant increase of apoptosis. Additionally, SF-1 gene overexpression was identified in 13% and 15% of pediatric and adult adrenocortical tumors, respectively. The percentual of neoplastic cells with nuclear immunoreactivity for SF-1 was significantly higher in pediatric than in adult adrenocortical tumors (29.1 ± 5.4% vs. 8.3 ± 2.3%, respectively; p= 0.0001). These findings suggest that SF-1 overexpression occurs at the translational level in pediatric adrenocortical tumors. DAX-1 gene overexpression was identified in 39% of adrenocortical tumors with a similar frequency in children and adults. Similarly, DAX-1 protein overexpression was identified in 36% and 27% of pediatric and adult adrenocortical tumors, respectively. DAX-1 immunostaining on nuclei was not statistically different in benign and malignant adrenocortical tumors (29.2 ± 3.8% vs. 21.4 ± 5.8% of neoplastic cells, respectively; p= 0.12). Conclusion: IGF-II overexpression has a pivotal role to adrenocortical tumorigenesis. IGFIR overexpression was a potential biomarker of metastases in children with adrenocortical carcinoma. We demonstrated that a selective IGF-IR kinase inhibitor had anti-tumor effects in adult and pediatric ACT cell lines, suggesting that IGF-IR inhibitors represent a promising therapy for human adrenocortical carcinoma. In addition, SF-1 overexpression might be mainly involved in pediatric adrenocortical tumorigenesis. DAX-1 overexpression has an important role to molecular pathogenesis of benign and malignant adrenocortical tumors

Encapsulation d'adn dans des liposomes contenant du lactosylceramide dont le sucre terminal est reconnu specifiquement par des recepteurs presents sur la membrane plasmique des cellules visees, c. A. D. , les hepatocytes et les cellules endotheliales du foie et egalement les lymphocytes de la rate. Injection par voie intraveineuse des liposomes. Role de l'endocytose, dans leur internalisation. Modele genetique constitue du gene de la preproinsuline i de rat insere dans des vecteurs retroviraux permettant l'expression du gene dans des celules non insulogenes

A presente investigação teve por objetivo estudar o papel do eixo GH-IGF-IGFBP no tecido hepático e nos linfócitos T e B de pacientes portadores do vírus da hepatite C, em terapia com INF-alfa e ribavirina nos períodos pré e pós-tratamento. Dados da literatura têm evidenciado o envolvimento do IGF-I na modulação da resposta imune, bem como sua atuação como fator de crescimento para células imunológicas, além de apresentar valor preditivo na avaliação da reserva hepática desses pacientes. O número final de pacientes abordados perfez o total de 80. Destes, 39 iniciaram tratamento conforme protocolo estabelecido pela equipe clínica. Quatro pacientes foram excluídos durante o curso do tratamento, sendo 2 por óbito e 2 por transtorno depressivo grave com ideação suicida. Dos 35 pacientes que concluíram o tratamento, 18 apresentaram resposta virológica ao final do tratamento. Destes, 15 pacientes (43%) obtiveram resposta virológica sustentada (RVS). As médias das U.A. (unidades arbitrárias) das enzimas AST e ALT foram estatisticamente diferentes entre os períodos pré e pós-tratamento, tanto para os pacientes que apresentaram RVS quanto para aqueles que não apresentaram tal resposta. No grupo de pacientes com RVS, observou-se que a média dos níveis basais de AST foi menor quando comparada à do grupo de pacientes sem RVS. A média das concentrações plasmáticas basais de IGF-I livre no grupo de pacientes com RVS foi estatisticamente maior quando comparada à do grupo de pacientes não respondedores. As médias das concentrações de IGFBP3 circulante no período pós-tratamento foram estatisticamente diferentes entre os grupos com e sem RVS. Um aumento do conteúdo de mRNA do gene do IGF-IR foi observado em tecido hepático de todos os pacientes com HCC quando comparado com o tecido hepático normal. Este resultado foi confirmado por análise imuno-histoquímica para o IGF-IR. Nos pacientes que apresentaram RVS a magnitude de expressão de mRNA do IGF-IR em amostras de tecido hepático após o tratamento foram estatisticamente menores em relação ao basal. Tal fato não foi observado no grupo de pacientes não respondedores. Não houve diferença estatisticamente significativa entre a média do conteúdo de mRNA do IGF-I em tecido hepático dos grupos de pacientes com e sem RVS, pré ou pós-tratamento. A média do conteúdo de mRNA do IGF-I em linfócitos T no grupo de pacientes com RVS foi estatisticamente maior em relação à do grupo de pacientes não respondedores quando se consideram os períodos pré e pós-tratamento conjuntamente. Não se observou diferença estatisticamente significativa entre as médias do conteúdo de mRNA do IGF-IR nos grupos com e sem RVS, pré ou pós-tratamento. Não houve diferença estatisticamente significativa entre as médias do conteúdo de mRNA de IGF-I e IGF-IR em linfócitos B de pacientes portadores do VHC, com e sem RVS e nos períodos pré e pós-tratamento. A diminuição de expressão de mRNA do IGF-IR em tecido hepático, observada no grupo de pacientes com RVS, sugere uma melhora da doença hepática. A hipótese de que um efeito do INF-? sobre os componentes do sistema IGF possa contribuir para este achado não pode ser descartada, porém, é provável que este efeito não seja tão importante, pois não se observou diferença nos níveis de expressão do IGF-IR hepático no grupo de pacientes não respondedores. Embora a supra-regulação (\"up-regulation\") do IGF-IR possa participar da regeneração hepática, é preciso elucidar se o aumento da expressão do IGF-IR na HCC resulta da ativação direta do gene pelo VHC ou se é uma conseqüência da agressão ao parênquima. As concentrações plasmáticas de IGF-I livre >1,35 ng/mL puderam ser consideradas preditivas da resposta ao tratamento da hepatite C com uma razão de probabilidade (\"odds ratio\") de 17,33±1,02 (Limite de confiança: 2,26-127,34)
The current investigation aimed to study the role of the GH-IGF-IGFBP axis in liver tissue and in T and B lymphocytes in patients with hepatitis C virus (HCV) before and after therapeutic regimen based on interferon alfa-2a or alfa-2b (3 million U SC 3x/wk) and ribavirin (1000-1200 mg qid). It has been shown that IGF-I plays an important role in the modulation of the immune response, besides its role as a growth factor for the immunologic cells. It also presents a predictive value in the evaluation of the hepatic reserve of these patients. Among 80 patients enrolled for this investigation, 39 began treatment with interferon-? and ribavirin, according to an established protocol. Two patients were excluded during treatment due to severe depressive disorders accompanied by suicidal thoughts and 2 patients died. Of the 35 patients who concluded the treatment, 18 eventually presented virological response. Of these, 15 (43%) maintained sustained virological response (SVR). The levels of AST and ALT enzymes in both pre and post-treatment periods were statistically different for both patients with SVR and those who did not present such response. In the group with SVR, aminotransferases basal levels were statistically lower when compared to the group of patients without SVR. In the group of non-responsive patients, the average of the scores of parenchyma activity was statistically lower in post-treatment period when compared to pre-treatment period. Furthermore, comparing post-treatment periods in both groups with and without SVR, the average of the scores of parenchyma activity was statistically lower in the group without SVR when compared to the group with SVR. Mean plasma concentrations of free IGF-I before treatment in patients who eventually achieved SVR was statistically higher in comparison to the group of non-responsive patients. Mean plasma concentrations of IGFBP3 were statistically higher in the group with RVS when compared to the group of patients without SVR. An increase of IGF-IR mRNA content was observed in hepatic tissue from all patients with CHC in comparison to normal liver. These results were confirmed by immunohistochemical analysis for the IGF-IR. IGF-IR mRNA content in liver tissue samples from patients who achieved SVR after treatment was statistically lower than that observed before treatment There was not statistical difference between IGF-I mRNA content in hepatic tissues from both groups of patients with and without SVR, in pre and post-treatment periods. IGF-I mRNA expression in T lymphocytes from patients with SVR was statistically higher in comparison to the non-responsive group of patients, considering both pre and post-treatment periods altogether. No statistical difference was observed in IGF-IR mRNA expression in both groups of patients with and without SVR, in pre and post-treatment periods. The statistical analysis did not disclose any statistically significant differences in IGF-I or IGF-IR mRNA expressions in B lymphocytes from patients with or without SVR, in pre and post-treatment periods. A decrease in hepatic IGF-IR mRNA content observed in patients who achieved SVR after therapy, suggested an improvement in hepatic damage. The hypothesis that the INF-? affects components of the IGF system contributing to these findings could not be discarded. However, it is unlike that these effects would play relevant role because any differences were observed in the hepatic IGF-IR mRNA expression in non-responsive patients. It remains to be elucidated whether IGF-IR up-regulation would be involved in hepatocyte regeneration or CHC would result from direct activation of IGF-IR gene by HCV and/or as a consequence of chronic aggression to hepatic parenchyma. Plasma concentration of free IGF-I >1.35 ng/ml was considered to be a predictive response to the treatment of hepatitis C with a probability ratio (odds ratio) of 17.33±1.02 (confidence interval: 2.26 -127.34)

OBJETIVO: avaliação da expressão gênicado receptor do fator de crescimento semelhante à insulina de (Insulin-Like Growth Factor- IGF) 1 em células da granulosa luteinizadas do cumulusde mulheres não obesas, com sensibilidade à insulina normal, com síndrome dos ovários policísticos (SOP) tratadas e não tratadas com metformina. MODELO DO ESTUDO: prospectivo, longitudinal, randomizado. PACIENTES E MÉTODOS: avaliamos 12 mulheres com ciclosovulatórios, 9 mulheres com SOP e 8 mulheres com SOP e tratadas com metformina, ao menos 8 semanas na dose de 1.700 mg/dia. Todos os grupos foram similares com relação ao peso, ao índice de massa corporal (IMC), à circunferência da cintura e com sensibilidade à insulina normal. Todas as mulheres foram submetidas à estimulação ovariana controlada com uso de agonista de GnRH em protocolo longo e gonadotrofinas para ciclos de FIV/ICSI. As células da granulosa do cumulusforam obtidas por microdissecção dos cinco maiores folículos pré-ovulatórios. A expressão gênica do receptor de IGF-1 foi determinada com técnica da Reação da Polimerase em Cadeia a partir da Transcrição Reversa (Reverse transcriptase - Polymerase Chain ReactionRT-PCR) emiquantitativa. Foram avaliadas as concentrações séricas e foliculares de estradiol, progesterona, testosterona, hormônio folículo estimulante (Follicle-Stimulating Hormone- FSH), hormônio luteinizante (Luteinizing Hormone - LH), Sex Hormone-Binding Globulin(SHBG), glicose, insulina e IGF-1. Para análise estatística, foram utilizados os testes: ANOVA, Newman-Keuls, coeficiente de Pearsone regressão linear múltipla, sendo considerado nível de significância de 5%. RESULTADOS: não foram observadas diferenças com relação à expressão gênica do receptor de IGF-1 nos três grupos analisados (P>0,05). O número de oócitos (20,4 vs. 13,1 vs.11,5, P= 0,009), os níveis séricos de estradiol (1.896,00 pcg/mL vs. 985,20 pcg/mL vs.908,10 pcg/mL,P = 0,03) e testosterona (1,43 ng/mL vs.0,89 ng/mL vs. 0,82 ng/mL pcg/mL,P = 0,02) foram maiores no grupo de mulheres com SOP não tratadas com metformina em comparação com as mulheres com ciclos ovulatórios e tratadas com metformina, respectivamente. As mulheres com ciclos ovulatórios (50.710±42.520 ng/mL) apresentaram maiores concentrações foliculares de progesterona quando comparados com as mulheres com SOP tratadas (13.660±5.212 ng/mL) e não tratadas com metformina (17.680±6.644 ng/mL) (P=0,01). Na avaliação da regressão múltipla, a testosterona sérica não sofreu influência da expressão gênica do receptor de IGF-1 ou do IMC. CONCLUSÕES: as altas concentrações séricas de estradiol e testosterona, maior número de oócitos no grupo de mulheres com SOP não tratadas com metformina nos levam a concluir que mulheres com SOP provavelmente têm uma maior sensibilidade à estimulação da esteroidogênese ovariana quando comparadas com mulheres sem essa doença, embora não tenhasido encontrada diferença na expressão do receptor de IGF-1 nos trêsgrupos analisados. A similaridade dos resultados deste estudo entre mulheres com SOP tratadas com metformina e com ciclos ovulatórios nos levam a \"hipotetizar\" que um dos possíveis mecanismos de ação da metformina no sistema IGF-1 nas células da granulosa do cumulus poderia ser por mecanismos pós-receptores.
OBJECTIVE: evaluation of the gene expression of the IGF-I receptor in luteinized cumulus granulosa cells from non-obese women with normal insulin sensitivity and with polycystic ovarian syndrome (PCOS)treated or nor with metformin. STUDY MODEL: prospective,longitudinal, randomized. PATIENTS AND METHODS: we evaluated 12 women withovulatory cycles and 9 women with PCOS who had been treated for at least 8 weeks with a metformin dose of 1700 mg/day. All groups were similar interms of weight, body mass index (BMI), and waist circumference and all had normal insulin sensitivity. All women were submitted to controlled ovarian stimulation with a GnRH agonist in a long protocol and with gonadotropins for IVF/ICSI cycles. Cumulus granulosa cells were obtained by microdissection of the five largest pre-ovulatory follicles. Gene expression of the IGF-1 receptor was determined by semiquantitative RT-PCR. Serum and follicular concentrations of estradiol, progesterone, testosterone, FSH, LH, insulin, SHBG, and IGF-1 were determined. Data were analyzed statistically by ANOVA and by the Newman-Keuls test and the Pearson coefficient and linear multiple regression were calculated, with the level of significance set at 5%. RESULTS: no difference in geneexpression of the IGF-I receptor were observed between the three groups studied (P>0.05). The number of oocytes (20.4 vs. 13.1 vs. 11.5, P= 0.009) and the serum levels of estradiol (1,896.00 pcg/mL vs. 985.20 pcg/mL vs.908.10 pcg/mL,P = 0.03) and testosterone (1.43 ng/mL vs.0.89 ng/mL vs. 0.82 ng/mL pcg/mL,P = 0.02) were higher in the group of women with PCOS not treated with metformin than in women with ovulatory cycles and in women treated with metformin, respectively. The women with ovulatory cycles (50.710±42.520 ng/mL) presented higher follicular concentrations of progesterone compared with women with PCOS treated (13.660±5.212 ng/mL) or not with metformin (17.680±6.644 ng/mL) (P=0.01). Multiple regression revealed that serum testosterone was not affected by the gene expression of the IGF-1 receptor or by BMI. CONCLUSIONS: the high serum concentrations of estradiol and testosterone and the larger number of oocytes in the group ofwomen with PCOS not treated with metformin lead us to conclude that women with PCOS probably have greater sensitivity to stimulation ofovarian steroidogenesis than women without the disease, although no difference was detected in the expression of the IGF-I receptor between the three groups studied. The similarity ofthe present results for the women with PCOS treated with metformin and for the women with ovulatory cycles leads us to hypothesize that one of the possible mechanisms of action of metformin on the IGF-1 system in cumulus granulosa cells may be of the post-receptor type.

O Diabetes mellitus (DM) é um grande problema de saúde pública, projeções indicam que em 2030, 366 milhões de indivíduos sofrerão da doença. Durante os últimos anos, tornou-se evidente que a ausência de células produtoras de insulina é um denominador comum em todos os tipos de DM. Assim, várias pesquisas têm procurado desenvolver células produtoras de insulina in vitro. A betacelulina (BTC) é uma proteína ligante de EGFR, relacionada com a proliferação de células β pancreáticas in vitro e, com o aumento no metabolismo da glicose em modelos animais do diabetes. As células-tronco mesenquimais (MSCs) são células multipotentes, presentes na medula óssea, e vastamente estudadas para terapia celular. O objetivo do presente trabalho foi avaliar os efeitos da superexpressão do gene da betacelulina sobre células MSCs de ratos. Foi estabelecida uma cultura de longo termo de células MSCs. Após caracterização, estas foram submetidas à transfecção gênica com o gene da BTC por eletroporação. Células transfectadas foram cultivas em meio de cultivo D-MEM suplementado de 10mM Nicotinamida. Análises de radioimunoensaio demonstraram que 104 MSCs transfectadas com o gene da BCT foram capazes de produzir até 0,45 ng/mL de insulina in vitro. In vivo, as células MSC superexpressando BTC foram capazes de diminuir a hiperglicemia induzida por Streptozotocina em ratos. Nossos resultados demonstraram que os efeitos positivos da superexpressão de BTC em MSCs.
Betacellulin (BTC), a ligand of the epidermal growth factor receptor, has been shown to promote growth and differentiation of pancreatic β-cells and to improve glucose metabolism in experimental diabetic rodent models. Mesenchymal stem cells (MSCs) have already been proved to be multipotent. Recent work has attributed to rat and human MSCs the potential to differentiate into insulin secreting cells. Our goal was to evaluate the effects of betacellulin overexpression in rat MSCs. MSCs were characterized by flow cytometry and mesoderm differentiation markers. MSCs were electroporated with a plasmid containing BTC cDNA. Transfected cells were cultivated in H-DMEM with 10mM Nicotinamide. Radioimmunoassay analysis showed that 104 MSC-BTC cells produced up to 0,4ng/mL of insulin, in contrast, MSCs transfected with the empty vector produced insignificant levels of insulin. Also MSC-BTC cells were positive for insulin in immunohistochemistry. RT-PCR showed expression of pancreatic marker genes. When transplanted to streptozotocin diabetic rats, MSC-BTC cells could revert hyperglycemia. Our results demonstrate that BTC overabundance enhances glucose-induced insulin secretion in mesenchymal stem cells in vitro as well as in vivo.

Abstract Approximately 5.5% of all infants are born preterm (before 37 completed weeks of gestation) in Finland. Preterm birth is the cause of several life-threatening neonatal diseases and long-term morbidity. The most important risk factor for preterm birth is intrauterine infection and inflammation. Approximately 70% of preterm births have a spontaneous onset. Evidence suggests that genetic factors are involved in spontaneous preterm birth (SPTB), but knowledge about the actual genes conferring genetic predisposition is limited. The major aim of this work was to identify genetic factors that predispose to SPTB. Genome-wide linkage analysis was performed to identify genomic regions associating with SPTB in large northern Finnish families recurrently affected by SPTB. Genes near regions with linkage signals were subsequently analyzed in a Finnish case-control population of mothers and infants. Due to their roles in innate immunity, the genes encoding surfactant protein A (SP-A), SP-C, SP-D and mannose-binding lectin (MBL) were also investigated as candidates for SPTB in this population. In addition, expression of SP-C in human and mouse gestational tissues was examined. Linkage signals were detected on chromosome loci 15q26.3, Xq13.1 and Xq21.1 with the phenotype of being born preterm. In subsequent association analyses, the genes encoding the insulin-like growth factor 1 receptor (IGF1R) located within locus 15q26.3 and the androgen receptor (AR) located near locus Xq13.1 were identified as potential novel fetal SPTB susceptibility genes. These genes did not associate with SPTB in the mothers. An association was found between the Met31Thr polymorphism of the SFTPD gene encoding SP-D and SPTB in the infants. There was no association in the mothers. Polymorphisms of the genes encoding SP-A or MBL did not associate with SPTB. The Thr138Asn polymorphism of the SFTPC gene encoding SP-C did not associate with SPTB. However, this polymorphism associated strongly with the interval between preterm premature rupture of membranes and SPTB in the fetuses. Expression of SP-C was detected in human and mouse fetal membranes and placenta, and in mouse pregnant uterus. Currently, there is no effective method to prevent SPTB. The results of this study may help to clarify some of the biological mechanisms underlying SPTB and finally allow the development of specific treatment strategies for its prevention
Tiivistelmä Suomessa syntyy noin 5,5 % lapsista ennenaikaisina eli raskauden kestettyä vähemmän kuin 37 täyttä viikkoa. Näillä lapsilla on alttius hengenvaarallisiin sairauksiin, ja osalle heistä jää pysyvä kehitysvamma. Noin 70 % ennenaikaisista syntymistä käynnistyy spontaanisti. Tärkein ennenaikaisen syntymän riskitekijä on kohdunsisäinen tulehdusreaktio. Myös perinnöllisten tekijöiden tiedetään vaikuttavan spontaanin ennenaikaisen syntymän (SEAS) käynnistymiseen, mutta alttiusgeenejä tunnetaan huonosti. Työssä pyrittiin tunnistamaan SEAS:lle altistavia perinnöllisiä tekijöitä. Perimänlaajuista kytkentäanalyysiä käyttäen etsittiin SEAS:ään liittyviä perimän kohtia tutkimalla toistuvasti ennenaikaisia syntymiä kokeneita isoja pohjoissuomalaisia perheitä. Kytkentäsignaalien lähellä olevia geenejä tutkittiin tutkimusaineistossa, joka koostui suomalaisista äideistä ja lapsista. Surfaktanttiproteiini A:ta (SP-A), SP-C:tä, SP-D:tä ja mannoosia sitovaa lektiiniä (MBL) koodaavia geenejä tutkittiin ehdokasgeeneinä SEAS:lle tässä populaatiossa, koska nämä proteiinit osallistuvat elimistön puolustukseen ja voivat siten vaikuttaa SEAS:ään liittyvään tulehdusreaktioon. Lisäksi tutkittiin SP-C:n ilmentymistä ihmisen ja hiiren sikiökalvoilla, istukassa ja kohdussa. Kytkentäsignaaleja havaittiin kromosomikohdissa 15q26.3, Xq13.1 ja Xq21.1, kun tutkittavana ilmiasuna oli ennenaikaisena syntyminen. Lisätutkimukset osoittivat, että sikiön insuliininkaltaisen kasvutekijän 1 reseptoria koodaava IGF1R-geeni (kohta 15q26.3) ja androgeenireseptorigeeni AR (lähellä kohtaa Xq13.1) ovat mahdollisia uusia SEAS:n alttiusgeenejä. Nämä geenit eivät selittäneet SEAS:ää äideissä. Sikiön SP-D:tä koodaavan geenin Met31Thr-polymorfismi tunnistettiin mahdolliseksi riskitekijäksi, mutta tämä polymorfismi ei selittänyt SEAS:ää äideissä. SP-A:ta ja MBL:ää koodaavat geenit eivät liittyneet SEAS:ään. SP-C:tä koodaavan geenin Thr138Asn-polymorfismi ei ollut yhteydessä SEAS:ään. Sikiön Thr138Asn-polymorfismi liittyi kuitenkin vahvasti sikiökalvojen puhkeamisen ja SEAS:n väliseen kestoon. SP-C:n havaittiin ilmentyvän ihmisen ja hiiren sikiökalvoilla ja istukassa sekä raskaana olevan hiiren kohdussa. Tulokset antavat uutta tietoa SEAS:n perinnöllisestä taustasta. Tämä tieto voi auttaa selvittämään sen käynnistymiseen johtavia biologisia mekanismeja ja johtaa lopulta uusiin hoitokeinoihin, joilla pystytään estämään spontaaneja ennenaikaisia syntymiä

Na patogênese do diabete melito tipo 1 (DM1) vários genes e fatores ambientais, como as infecções virais, interagem para iniciar um ataque autoimune contra as células beta pancreáticas. Durante a fase inicial desse processo, as células beta desempenham um papel importante através da promoção de um “diálogo” com o sistema imune. Recentemente, o uso de técnicas de genotipagem em larga escala proporcionou um aumento significativo no número de genes conhecidos potencialmente associados ao desenvolvimento do DM1. Para compreender como esses novos genes candidatos modificam as respostas das células beta pancreáticas a mediadores inflamatórios e aos vírus, nós analisamos os dados de estudos prévios de array e um banco de dados online (www.t1dbase.org) para identificar os genes expressos nas células beta e modificados por citocinas ou pelo subproduto da replicação viral, RNA de fita dupla (RNAfd). Dois genes foram selecionados para serem estudados nesta tese, PTPN2 e MDA5. PTPN2 é uma proteína tirosina fosfatase que tem entre os seus alvos o STAT1, um fator de transcrição chave no processo de morte das células beta. Inicialmente, confirmamos a presença de PTPN2 pela quantificação do seu RNAm e produto protéico em uma linhagem de células beta (INS-1E), células beta primárias de rato purificadas por FACS e ilhotas humanas. Tratamento com citocinas ou RNAfd intracelular significativamente aumentou a sua expressão. O knockdown específico deste gene pela técnica de RNA de interferência aumentou significativamente a apoptose das células beta expostas a uma combinação de citocinas (interleucina-1! (IL-1!) + interferon-" (IFN-")) ou RNAfd intracelular, e converteu IFN-" isoladamente em um estímulo pró-apoptótico. O silenciamento do PTPN2 amplificou a fosforilação do STAT1. O duplo knockdown, PTPN2 + STAT1, protegeu as células beta contra a apoptose induzida por citocinas, sugerindo que PTPN2 age como um regulador negativo dos efeitos pró-apoptóticos do STAT1. Contudo, o silenciamento do PTPN2 não produziu nenhuma alteração maior na expressão de citocinas e quimiocinas. O segundo gene candidato, MDA5, é uma helicase associada com o reconhecimento de ácidos nucléicos virais intracelulares. A principal função do MDA5 é a detecção de infecções virais; sendo assim, esse gene foi avaliado apenas no contexto do mimético viral RNAfd. A transfecção de células INS-1E e células beta primárias de rato purificadas por FACS com RNAfd induziu um aumento significativo no RNAm codificando MDA5. O silenciamento do MDA5 e do RIG-I (outra helicase envolvida no reconhecimento do RNAfd intracelular) não modificou a frequência da apoptose induziu por RNAfd. Por outro lado, o knockdown do MDA5, mas não do RIG-I, significativamente reduziu a expressão de várias citocinas/quimiocinas produzidas pelas células beta expostas ao RNAfd intracelular. Concluindo, os dados apresentados sugerem que esses dois genes candidatos, através de suas funções nas células beta, podem ter importantes papéis no desenvolvimento do DM1. PTPN2 aparentemente previne a apoptose das células beta controlando a ativação do STAT1, enquanto MDA5 pode regular o ataque imune local através da diminuição no recrutamento e ativação das células do sistema imune.
In type 1 diabetes (T1D) several genes and environmental factors, such as viral infections, interact to trigger a chronic autoimmune assault against the insulin-producing pancreatic beta cells. During this process beta cells have an important role in maintenance/amplification of this autoimmune response via a cross-talk with the immune system. In recent years the development of high-throughput techniques for searching new genetic variants significantly increased the number of known genes potentially contributing for T1D. To clarify how these new candidate genes modify pancreatic beta responses to proinflammatory mediators and viruses, we used data from our previous array studies and an online beta cell database (www.t1dbase.org) to select candidate genes that are expressed in beta cells and modified by cytokines or the viral by-product double-stranded RNA (dsRNA). Two genes were identified, PTPN2 and MDA5, and further studied in this thesis. PTPN2 is a protein tyrosine phosphatase with several targets including STAT1, a key transcription factor involved in beta cell death. We confirmed at mRNA and protein levels the expression of PTPN2 in a beta cell linage (INS-1E), primary FACS-purified rat beta cells and human islets. Exposure to cytokines or to intracellular dsRNA increased PTPN2 expression. Knockdown of PTPN2, by using specific small interference (si)RNAs, exacerbated beta cell apoptosis after treatment with a combination of cytokines (interleukin-1! (IL-1!) + interferon-" (IFN-")) or intracellular dsRNA, and converted IFN-" alone in a pro-apoptotic stimulus. Importantly, PTPN2 silencing amplified STAT1 phosphorylation. The double knockdown of PTPN2 and STAT1 protected beta cells against cytokine-induced apoptosis, suggesting that PTPN2 acts as a negative regulator of the pro-apoptotic transcription factor STAT1. Knocking-down PTPN2, however, did not affect to any major extent the expression of cytokines and chemokines. The second candidate gene, MDA5, is an helicase involved in recognition of intracellular viral nucleic acids. Since MDA5 works as a receptor for detection of viral infection, this gene was only evaluated in the context of the viral mimetic dsRNA. Transfection of INS-1E cells and FACSpurified rat beta cells with dsRNA significantly upregulated the mRNA expression of MDA5. The silencing of MDA5 and RIG-I (another helicase involved in recognition of intracellular dsRNA) did not modify dsRNA-induced apoptosis. On the other hand, the knockdown of MDA5, but not of RIG-I, decreased the expression of several cytokines/chemokines in beta cells exposed to intracellular dsRNA. In conclusion, our data suggest that these two candidate genes may have important roles in the development of T1D via their actions at the beta cell level. PTPN2 seems to prevent beta cells apoptosis by controlling STAT1 activation, while MDA5 might regulate the local autoimmune assault via decreasing recruitment and activation of immune cells.

As doenças que comprometem o crescimento humano apresentam uma forte influência genética. O objetivo geral do projeto atual é desenvolver e aplicar a tecnologia de sequenciamento paralelo em larga escala para compreensão desses distúrbios de crescimento, com foco principal em crianças nascidas pequenas para idade gestacional (PIG), definida como criança com Escore-Z de comprimento e/ou peso ao nascimento menor ou igual a -2. PIG é uma condição heterogênea, que inclui como causa fatores maternos, placentários e fetal, dentre o qual, destacam-se as alterações genéticas. Crianças nascidas PIG e que não recuperaram seu déficit estatural espontaneamente nos primeiros anos de vida apresentam uma alta probabilidade de serem adultos baixos e costumam evoluir com quadros clínicos complexos, envolvendo retardo de crescimento persistente na vida pós-natal, dismorfismos, anomalias congênitas e distúrbios de desenvolvimento neuropsicomotor. Foi utilizada a tecnologia de sequenciamento Sure Select (Agilent Technologies, CA, USA) para estudar aproximadamente 390 genes escolhidos por pertencerem à via IGFs/IGF1R, principal eixo regulador hormonal do crescimento, genes sabidamente envolvidos em doenças associadas com distúrbio de crescimento, além de genes candidatos identificados em estudos prévios do laboratório, associados à regulação do crescimento, em um grande número de pacientes. Foram sequenciados 80 pacientes, obtendo uma cobertura média de 354 vezes e com mais de 99% da região alvo com cobertura > 10 reads. Nestas amostras foram identificadas 58 variantes, 18 consideradas patogênicas ou provavelmente patogênicas em 19 pacientes, 32 de significado incerto, 7 provavelmente benigna e 1 provavelmente patogênica para condição não associada a distúrbio de crescimento (\"achado acidental\"). Dentre as variantes consideradas patogênicas ou provavelmente patogênicas houve uma grande heterogeneidade entre os genes, sendo identificadas variantes nos genes PTPN11 (x3), BLM (x3), NPR2 (x2), ANKRD11 (x2), SRCAP (x2), FGFR3 (x2), IGF1R, SHOC2, SHOX, NIPBL e deleção 22q11. Podemos concluir que a técnica de sequenciamento paralelo em larga escala de genes alvo é eficiente em estabelecer o diagnóstico molecular de crianças nascidas PIG. Foi possível identificar a etiologia genética em 23,75% da casuística estudada, em sua maior parte, de pacientes com síndromes reconhecidas clinicamente. Contudo, defeitos no sistema IGFs/IGF1R não foram frequentes nesta condição
Diseases affecting human growth are most likely caused by genetic factors. The main goal of this project is to apply the technology of massive parallel sequencing to comprehend growth disturbs in children born small for gestational age (SGA), known as the children with Z-score of height and/or weight at birth less or equal -2. SGA is a heterogeneous condition, and as its causes we can find maternal, placental and fetal factors, of which, the most important are the genetic alterations. Children born SGA that do not have catch-up growth spontaneously up to the second year of life may remain with short stature when adults and they usually present other clinical features, such as dimorphisms, congenital anomalies and neuropsychomotor developmental delay. We used the Sure Select technology (Agilent Technologies, CA, USA) to study approximately 390 genes chosen by participate of the IGFs/IGF1R system, or genes already associated with growth disorders, or candidate genes found in previous studies of aCGH (Array Comparative Genomic Hybridization) or exome sequencing. We sequenced 80 patients, and had a mean coverage of 354x, with more than 99% of the target region with > 10 reads. We found 58 variants, 18 classified as pathogenic or probably pathogenic in 19 patients, 32 variants of unknown significance and 7 probably benign and 1 probably pathogenic for a condition non associated to short stature (``incidental finding``) Among the probably pathogenic and pathogenic we found a great heterogeneity in genes, with variants identified in 10 different genes PTPN11 (x3), BLM (x3), NPR2 (x2), ANKRD11 (x2), SRCAP (x2), FGFR3 (x2), IGF1R, SHOC2, SHOX, NIPBL and a 22q11 deletion. In conclusion, the technique of targeted gene panel sequencing is a useful tool to establish the molecular diagnose in children SGA. We could identify the molecular cause in 23.75% of the casuistic, mostly patients with clinically recognized syndromes. However, variants at IGFs/IGF1R system are not frequently associated with the studied condition

La croissance fœtale est sous la dépendance de nombreux facteurs environnementaux, génétiques et hormonaux dont les interactions vont en conditionner le bon déroulement. Le système des insulin-like growth factors (IGFs) joue un rôle prépondérant, à l’interface de ces différents facteurs, pour assurer une bonne croissance fœtale. Dans ce travail, nous nous sommes intéressés aux différents acteurs du système des IGFs dans des pathologies de la croissance fœtale. Dans une approche clinique et expérimentale, nous avons décrit les conséquences fonctionnelles d’anomalies génétiques ou épigénétiques intéressant IGF-I, IGF-II et leur récepteur commun IGF1R. Ainsi, nous avons mis au point un test fonctionnel permettant d’apprécier l’activité in vitro d’IGF1R chez les patients présentant une restriction de croissance fœtale et postnatale. Nous avons également documenté la biodisponibilité d’IGF-I chez des patients présentant un syndrome de Silver-Russell, qui est une pathologie liée à l’empreinte parentale responsable d’une restriction de croissance à début ante-natal. Enfin, nous avons caractérisé le chevauchement clinique et moléculaire entre les patients présentant un SRS ou un syndrome de Temple (autre pathologie liée à l’empreinte parentale), confirmant le rôle prépondérant du défaut d’expression d’IGF2 dans ces deux syndromes. Ces résultats confirment un fonctionnement des gènes soumis à empreinte en réseau et le rôle majeur du système des IGFs dans la croissance fœtale, particulièrement altérée en cas de pathologie intéressant ces gènes soumis à empreinte parentale
Fetal growth is dependant of environemental, genetic and hormonal factors which interact to ensure a proper development. Insulin-like growth factors (IGF) system plays a key role in fetal growth by interactions with these differents systems. In this work, we studied the roles of the IGF system in fetal growth restriction diseases. We used both clinical and experimental approaches to enhance knowledge on functional consequences of genetic ou epigenetic defects of IGF system actors. We set-up a functional test to assess IGF1R activity in vitro in patients with restricted fetal and postnatal growth. We also documented the IGF-I bioavailability in patients with Silver-Russell syndrome, which is an imprinting disorder responsible for fetal and postnatal growth restriction. We characterized the clinical and molecular overlap of Silver-Russell and Temple syndrome (another imprinting disease affecting growth and metabolism) and confirmed the central role of IGF2 in the physiopathology of these disorders. These results confirmed the integration of imprinted genes in a large co-regulation network and the major role of IGF system actors in fetal growth which is usually impaired when these imprinted genes are affected

博士
國防醫學院
生命科學研究所
90
The characteristics of high growth rate, easy breeding and maintenance have made the zebrafish (Danrio rerio) as world-wide recognized species and important embryo model for functional genomics and proteomics research in the post-genomics era. This dissertation focused on the zebrafish growth related genes and its function, especially IGF-1, IGF-2 and IGF-1R. In this study, we plan to dissect the mechanisms of paracrine/autocrine modes of IGF action in the thorax development. We cloned zebrafish (Danio rerio) IGF-1 cDNA and its genomic sequence from zebrafish brain cDNA library and an adult zebrafish genomic library, respectively. These two cDNA sequences differ from with each other in different length of 5- and 3-untranslated region (5UTR and 3UTR) and one nucleotide difference at glutamine (A9, CAG/IGF-1a and CAA/IGF-1b) of the A domain. The results of IGF-1 mRNA expression and genomic Southern blotting, RPA, 5悐ACE suggested that the zebrafish have more than two IGF-1 genes. All these findings suggest that the expression of pro-IGF-1 Ea-2 is not controlled by alternative splicing but alternative gene usage in the zebrafish. Results of RT-PCR and Southern blot analysis showed that, only one form of IGF-1 Ea-2 mRNA was expressed in all tested adult tissues of zebrafish, even under condition of growth hormone, prolactin or insulin administration and fasting. The encoding proIGF-1a Ea-2 protein is 100% identity to proIGF-1b Ea-2. So, we tested the hypothesis whether E domain can mimic IGF-1 function. In this research, a synthetic peptide of the predicted zebrafish Ea-2 polypeptide (designated as zfEa-2) was not only increased 3 fold of branchial cartilage specific sulfate uptake in vitro compared with control group but also increased the [3H]thymidine incorporation into DNA on the mouse spleen cell. For further understanding the zfEa-2 polypeptide action mechanism, the aIR-3 was used to block the IGF-1 signal transduction. We demonstrated that aIR-3 couldn掐 inhibit the zfEa-2 signal but inhibit the IGF-1 sulfate uptake capability. These findings strongly suggest that the zfEa-2 can mimic IGF-1 function as a local mediator in zebrafish. These findings strongly suggest that the zfEa-2 polypeptide has another receptor to trigger the sulfation signal in zebrafish. Finally, The IGFs system exhibits an important role on the zebrafish development. So, we are further cloning the IGF-2a cDNA and IGF-2b gene from library. Meantime, we are search one zebrafish IGF-1Ra EST clone and get the 5UTR sequence for morpholino gene knock-down functional assay. In conclusion, this dissertation hopes to provide a new vision on the IGF gene family (IGF-1, IGF-2, IGF-1R) to distribute onto the growth regulation mechanism. Based on these researches, it can provide some information to construct the growth gene-chip network in the future.

碩士
國立東華大學
生物技術研究所
96
Nuclear receptors are a family of transcription factors. They can bind to hormone response elements of target genes, control their expression, and many important physiology processes. The ligands of many nuclear receptors have not been identified, so they are called orphan receptors. TR4 is an orphan receptor. TR4 can control gene expression, animal growth and development, and the function of the liver. Collins and associates observed insulin-like growth factor-I (IGF-I) decreases in the blood and the liver of TR4 gene knockout mice in 2003. IGF-I regulated the body growth of human and mice. Therefore, we hypothesized TR4 was an potential activator of IGF-I gene expression. To demonstrate our hypothesis, we selected four sequence, IGF-DR2，IGF-DR4，IGF-DR6 and IGF-rDR4, to perform electrophoresis mobility assay (EMSA) and dual-luciferase assay. The result of EMSA suggested TR4 could bind to IGF-DR6 and IGF-rDR4. The result of dual-luciferase assay suggested TR4 interacted with IGF-DR6 and GF-rDR4 in HeLa cell line acted a repressor. However, the result was opposite our original hypothesis. The reason was that HeLa cell line wasn’t derived from the liver tissue. Our study showed TR4 might participate to regulate IGF-I gene expression. Furthermore, we will detect the effect of TR4 on IGF-I gene expression to demonstrate whether TR4 can regulate IGF-I gene expression in cells.

碩士
臺北醫學大學
公共衛生學研究所
96
The cross-sectional study was conducted to explore the relationships among arsenic methylation capability, genetic polymorphisms of insulin receptor substrate-1 (IRS-1) codon 972 and phosphatidylinositol 3-kinase (PI3-K) codon 326, cigarette smoking, betel nut chewing and metabolic syndrome. The study subjects were recruited from commuity health examination of Puzih, Taibao and Budai Township of Chayi County in southwestern Taiwan. A standardized personal interview based on structural questionnaire was carried out by well-trained interviewers. Information obtained from interview included demographic characteristics, environmental exposure, personal and familial disease history and lifestyle. There were 900 study subjects who gave their consent were recruited for questionnaire interview and collectd their blood and urine samples. Random selected 560 subjects to carry out the gene polymorphism experiment. DNA was extracted from buffy coat to analyze the gene polymorphism of the IRS-1 codon 972 and PI3-K codon 326 utilizing the polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) assay. Urine samples of these subjects were examined by high performance liquid chromatography (HPLC) to separate arsenite (AsIII), dimethyarsinic acid (DMAV) monomethylarsonic acid (MMAV) and arsenate (AsV), and then quantified by hydride generator combined with atomic absorption spectrometry (HG­AAS). It was found that metabolic syndrome prevalence was 28.89%. After adjusted potential confounders, subjects had cumulative betel nut exposure ＞7.49 × 104 year-quids compared to those who had cumulative betel nut exposure 0 year-quids, the metabolic syndrome risk was significantly increased, the odds ratio was 1.97, 95% confidence interval was 1.05 - 3.70. Subjects had cigarette smoking, alcohol drinking and betel nut chewing compared to non smoker, non drinking and non chewer, the metabolic syndrome risk was borderline significantly increased, the odds ratio was 1.86, and 95% confidence interval was 0.99 - 3.51. Total arsenic concentration, MMA%, DMA% and SMI were divided into three groups using their tertile of controls, respectively. The odds ratio of metabolic syndrome was significantly increased for those second tertile versus first tertile group. There were no associations among IRS-1 codon 972 or PI3-K codon 326 polymorphisms and the metabolic syndrome risk. The metabolic syndrome risk was significantly higher in the study subjects had cigarette smoking, alcohol drinking, betel nut chewing, worse arsenic methylation capability, and PI3-K codon 326 Met/Ile or Ile/Ile genotype than those with non smoker, non drinker, non betel nut chewer, better arsenic methylation capability, and PI3-K codon 326 Met/Met genotype.