Dissertations / Theses on the topic 'Collagen Type 1 CTGF'
To see the other types of publications on this topic, follow the link: Collagen Type 1 CTGF.
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 39 dissertations / theses for your research on the topic 'Collagen Type 1 CTGF.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Zhou, Zhenqing. "BIOLOGICAL SIGNIFICANCE OF HEPARIN-BINDING GROWTH FACTORS HB-EGF AND CTGF." Miami University / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=miami1258498601.
Full text
2
Mackay, Katrina. "Molecular analysis of type 1 collagen genes in inherited disorders." Thesis, University of Leicester, 1992. http://hdl.handle.net/2381/34442.
Full textAbstract:
The collagens are a family of related proteins which contain at least one triple-helical domain, a structure which is determined by the unique amino acid sequence of the polypeptide subunits. These proteins each have a specific function in the extracellullar matrices of connective tissues of multicellular organisms. In humans, type I collagen, the most abundant collagen type, is the major structural component of skin, tendon and bone. Mutations in the two genes encoding the subunits of type I collagen, COL1A1 and COL1A2, result in heterogeneous phenotypes. Some mutations result in osteogenesis imperfecta, the "brittle bone disorder", which itself has a wide range of phenotypes from mild to lethal in utero and others result in Ehlers-Danlos syndrome type VII, which is characterized by skin hyperextensibility and joint laxity. In this study, mutations were detected in these two genes using an adaptation of a recently-developed technique, single strand conformation polymorphism analysis, and DNA sequencing. Several silent changes in COL1A1 were identified and characterized. Two of these, an intronic HaeIII restriction fragment length polymorphism and an AciI polymorphism, are both of sufficient frequency to be potentially useful as markers in linkage analysis studies. The AciI polymorphism, resulting in substitution of an alanine residue with threonine, and a proline to alanine change were both found in normal individuals and therefore the altered amino acid residues do not appear to have any crucial role in the type I collagen molecule. Four patients with Ehlers-Danlos syndrome were studied but no mutations were identified. Several different mutations, assumed to result in the disorder, were found in coding sequences of COL1A1 or COL1A2 in patients with lethal and non-lethal forms of osteogenesis imperfecta. The discovery of these mutations has extended the knowledge of the relationship between the type and position of the mutation and the resulting phenotype.
3
Tang, Ming. "Atomic-scale biophysics modelling of type I collagen in the extracellular matrix." Thesis, Queensland University of Technology, 2019. https://eprints.qut.edu.au/124650/1/Ming_Tang_Thesis.pdf.
Full textAbstract:
This thesis explores the biophysics of collagen in the extracellular matrix under external stimuli, by performing cutting edge MD simulations. The obtained results provide significant insights into the design and manufacturing of artificial biomaterials for surgical tissue treatments, of collagen for regenerative medicine applications, and of gold nanoparticles for biomedical applications. The probed biophysical properties consist of the structural properties and the mechanical properties, where the mechanical properties of collagen are regulated by its structure at different levels of hierarchies.
4
Dzobo, Kevin. "Matrix-mediated regulation of type 1 collagen synthesis and degradation in cultured fibroblasts." Doctoral thesis, University of Cape Town, 2009. http://hdl.handle.net/11427/3125.
Full textAbstract:
Includes abstract.Includes bibliographical references (leaves 122-157).
Stromal cells and the extracellular matrix (ECM) components provide the microenvironment that is pivotal for cell growth, motility, attachment and differentiation. Fibroblasts are some of the cells responsible for the synthesis of most of the extracellular matrix proteins. Type I collagen is the most abundant extracellular matrix protein in the human body and is found in tissues requiring high tensile strength. In this study we investigated the effect of a pre-formed fibroblast-derived extracellular matrix on the expression of type I collagen and associated matrix metalloproteinases in fibroblasts.
5
Soininen, Raija. "Structure of the gene for the [alpha] 1 chain of human type IV collagen." Oulu, Finland : University of Oulu, 1989. http://catalog.hathitrust.org/api/volumes/oclc/20482376.html.
Full text
6
Seehra, Kamaljit Jyoti Kaur. "An investigation into mechanisms inhibiting human microvascular endothelial cell (HMEC-1) capillary cord formation on collagen type 1." Thesis, University of Nottingham, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.438638.
Full text
7
Стужук, Анастасія Юріївна. "Способи отримання та перспективи застосування колагену типу 1." Магістерська робота, Київський національний університет технологій та дизайну, 2021. https://er.knutd.edu.ua/handle/123456789/19255.
Full textAbstract:
Дипломна магістерська робота присвячена вивченню способів отримання та перспектив застосування колагену типу 1 у різних галузях промисловості. У роботі наведено критичний огляд літературних джерел, присвячених застосуванню та отриманню колагену, обґрунтовано технологічну схему отримання сухого препарату колагену з відходів шкіряного виробництва за допомогою Bacillus subtilis, яка передбачає, в тому числі, стадії отримання посівного матеріалу, вирощування культури та культивування, поділ отриманого гідролізату на фракції та фільтрацію. Обґрунтовано вибір технологічного обладнання для реалізації виробництва. Дипломна робота включає біотехнологічні аспекти отримання колагену типу 1 та опис методів контролю стадій його виробництва та готового продукту.The master's thesis is devoted to the study of methods of obtaining and prospects for the use of collagen type 1 in various industries. The thesis provides a critical review of the literature on the usage and production of collagen, substantiates the technological scheme of obtaining of a dry preparation of collagen from leather waste using Bacillus subtilis, which includes, inter alia, stages of seed production, cultivation, separation of hydrolyzate on fractions and filtration. The choice of technological equipment for the realization of production is substantiated. Thesis includes biotechnological aspects of obtaining of collagen type land a description of methods for controlling the stages of its production and finished product.
8
Miles, Benjamin Nicholas. "On the use of collagen type-I in the growth of hydroxyapatite on micro-fabricated biomimetic dentin." Thesis, Imperial College London, 2015. http://hdl.handle.net/10044/1/58203.
Full textAbstract:
Dentin hypersensitivity is a condition that affects 4 – 14% of western populations like the U.K. It is characterised by a short sharp pain in the gums, usually experienced when an individual consumes cold food or drink. Typical treatments that are primarily delivered by sensitive toothpastes initially relied upon disruption of neuronal activity with potassium ions. However, more recently the most advanced over the counter treatments now act to occlude the tubules present in dentin that are involved in the hydrodynamic cause of dentinal pain. Pre-clinically, the efficacy of these occlusive treatments are assessed in a hydraulic conductance apparatus. This apparatus forces a simulated saliva through a thin section of dentin known as a Pashley dentin disc to determine a volumetric flow rate before and after treatment with the active of interest. Due to the innate variability of dentin a high degree of variability makes the assessment of novel actives difficult and unreliable. This body of work covers the attempt to fabricate a synthetic dentin disc that replicates the microstructure of the dentin and its tubules and in addition, the surface chemistry of the collagen and hydroxyapatite composite observed in dentin in vivo. The focus of this thesis is largely on the exploration of using collagen immobilised at the surface of this silicon mimetic dentin disc to template the growth of hydroxyapatite via a biomineralisation-like processes. An automated perfusion apparatus is used in attempt to mineralise a collagen coated mimetic dentin disc under conditions of continuous flow. A study of this flow mineralisation process over time was undertaken largely by Scanning Electron Microscopy. Whilst deposition of material was achieved at the mimetic dentin surface the full composition and morphology remained inconclusive however this work made significant headway into highlighting suitable routes forward in terms of fabrication and characterisation.
9
Afifi, Amal. "A molecular investigation into type 1 collagen genes in Osteogenesis imperfecta and an evaluation of targeted gene repair." Thesis, University of Sheffield, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.422178.
Full text
10
Ndlovu, Matladi N. "The role of DNA methylation in transcriptional regulation of the human type 1 alpha 2 collagen (COL1A2) gene." Master's thesis, University of Cape Town, 2002. http://hdl.handle.net/11427/3144.
Full textAbstract:
Bibliography leaves 70-97.Type I collagen is the most abundant collagen molecule in vertebrate connective tissue and it consists of a heterotrimer of two alpha 1 (COL1A1) and one alpha 2 (COL1A2) chains. Reduced collagen gene expression is almost always correlated with pathological conditions and cellular transformation. Numerous studies have suggested that methylation of the cytosines in CpG dinucleotides is inversely correlated with transcriptional activity and plays a critical role in differential gene expression.
11
Wei, Yi. "Type XII Collagen, Fibroblast Growth Factor-1, and Fibroblast Growth Factor-4 in Newt Limb and Tail Regeneration /." The Ohio State University, 1996. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487935125882142.
Full text
12
Grant, Struan F. A. "Studies on genetic susceptibility to osteoporosis : analysis of cis-acting sequences in the collagen type I alpha 1 gene." Thesis, University of Aberdeen, 1995. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU543267.
Full textAbstract:
In osteogenesis imperfecta, an osteoporotic phenotype results from mutations in the protein coding regions of the collagen type I genes - COLIA1 and COLIA2. Genetic factors are known to play an important role in determining bone mass. For this reason, it was considered that more subtle mutations in the transcriptional control regions of the collagen type I genes might be associated with osteoporosis. The polymerase chain reaction was used, followed by single-stranded conformation polymorphism detection (PCR/SSCP) to screen for polymorphisms in the transcriptional control regions (the promoter and first intron) of the type I 1 collagen gene. Three polymorphisms were found; two were rare (allelic frequency 3% and 4%) but the third was more common (allelic frequency 23%) and comprised a guanosine to thymidine substitution at the first base of a consensus sequence for an Sp1 binding motif - an important regulator of transcription in this collagen gene and many other genes. Since osteoporosis is a common disease and the polymorphism was at a functional site, this was investigated further. Electrophoresis mobility shift and supershift assays revealed that the G to T polymorphism was indeed an Sp1 binding motif. This technique also revealed that the T variant (designated "s") had twice the affinity for Sp1 than the G variant (designated "S"). Differential allelic expression analysis showed an increased rate in transcription associated with "s". On analysis of bone mineral density (BMD) in a cohort of 156 women, those with the "Ss/ss" genotype had significantly reduced BMD at the lumbar spine (p<0.03) when compared with "SS" homozygotes. A significant over-representation of the "s" containing genotypes was found in osteoporotic individuals with vertebral fracture (2=6.76;p<0,01). In combination with VDR genotypes, an 'at risk' genotype of "bb/s" was identified.
13
Salomonsson, Maya. "Exploring innate type B cells in an animal model for autoimmune arthritis." Thesis, Uppsala universitet, Institutionen för biologisk grundutbildning, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-229792.
Full textAbstract:
B cells have a central role in the pathogenesis of collagen-induced arthritis (CIA), an animal model of the autoimmune disease rheumatoid arthritis. In this report, a specific subset of an innate type of B cells, B-1 B cells, have been studied for the involvement in CIA. The B-1 B cells were shown to produce small amounts of collagen-specific antibodies upon stimulation in vitro, suggesting that they play a minor role in the development of CIA. This report also includes how marginal zone B cells, another innate type of B cells with natural collagen-reactivity, can be identified in the medullary sinuses of lymph nodes of collagen-immunized mice, implying involvement in auto antigen trapping.
14
Pillusky, Fernanda Maia. "INFLUÊNCIA DO FOTOSSENSIBILIZADOR AZUL DE METILENO DISSOLVIDO EM ETANOL NA TERAPIA FOTODINÂMICA ANTIMICROBIANA SOBRE O STATUS OXIDATIVO SISTÊMICO E COLÁGENO GENGIVAL EM MODELO EXPERIMENTAL DE PERIODONTITE." Universidade Federal de Santa Maria, 2015. http://repositorio.ufsm.br/handle/1/6173.
Full textAbstract:
The purpose of this study was to evaluate the effects of an antimicrobial photodynamic therapy (aPDT) employing the photosensitizer methylene blue dissolved in ethanol on the systemic oxidative status likewise on the gingival collagen content of rats with periodontitis. Male Wistar rats were randomly divided into two main groups: NC (negative control; no periodontitis) and the remaining animals were submitted to periodontitis induction group. In the last group, the cotton ligature was placed at the first right mandibular molar of each animal in a submarginal position to induce experimental periodontitis. The animals with periodontitis were subdivided into groups according to the periodontal treatment as follow: SRP group (scaling and root planing), aPDT I group (SRP+aPDT+MB dissolved in water), and aPDT II group (SRP+aPDT+MB dissolved in ethanol). After 7 days, the ligature was removed and periodontal treatments were performed. At 7, 15 and 30 days, rats were euthanized and gingival tissue was removed for morphometric analysis. The erythrocytes were used to evaluate systemic oxidative status. Besides that, it indicated a protective influence of aPDT II in erythrocytes already at 15 days observed by the elevation in levels of systemic antioxidant defense. The morphometric findings showed that aPDT II group was the only one that restored the percentage of total collagen area also in 15 days, as well as, aPDT II group recovered the type I collagen area at the same time-point. According to this study we could suggest that aPDT employed as an adjunct to the standard treatment of periodontitis (SRP) increases systemic protective response against oxidative stress periodontitis-induced facilitating and accelerating the periodontal healing particularly when methylene blue is dissolved in ethanol.O objetivo deste estudo foi avaliar os efeitos da terapia fotodinâmica antimicrobiana (TFDa) usando o fotossensibilizador azul de metileno (AM) dissolvido em etanol sobre o status oxidativo sistêmico, bem como sobre o conteúdo de colágeno gengival de ratos com periodontite. Ratos machos Wistar foram divididos aleatoriamente em dois grupos principais: CN (controle negativo; sem periodontite) e os animais restantes foram o grupo submetido a indução de periodontite. No último grupo, a ligadura de algodão foi colocada no primeiro molar inferior direito de cada animal em uma posição subgengival para induzir a periodontite experimental. Os animais com periodontite foram subdivididos em grupos de acordo com o tratamento periodontal, como segue: grupo RAR (raspagem e alisamento radicular), TFDa I grupo (RAR + TFDa + AM dissolvido em água), e grupo TFDa II (RAR + TFDa + AM dissolvido em etanol). Após 7 dias, a ligadura foi removida e foram realizados os tratamentos periodontais. Aos 7, 15 e 30 dias, os ratos foram submetidos à eutanásia e foi removido o tecido gengival para análise morfométrica. Os eritrócitos foram usados para avaliar o status oxidativo sistêmico. O status oxidativo demostrou maiores níveis de peroxidação lipídica no grupo CP em 7, 15 e 30 dias, e indicou uma influência protetora da TFDa II, nos eritrócitos, já em 15 dias, observada a partir da elevação dos níveis de defesa antioxidante sistêmica. Os achados morfométricos mostraram que o grupo TFDa II restabeleceu o percentual de área total de colágeno também em 15 dias, bem como recuperou a área de colágeno tipo I no mesmo tempo. A partir deste estudo podemos sugerir que TFDa utilizada como um adjuvante ao tratamento padrão periodontal (RAR) aumenta a resposta protetora sistêmica contra o estresse oxidativo induzido pela periodontite, facilitando e acelerando a cicatrização periodontal, particularmente quando o azul de metileno é solubilizado em etanol.
15
Welander, Maria. "Soft tissue integration to dental implants /." Göteborg : Deptartment of Periodontology, Institute of Odontology, The Sahlgrenska Academy at University of Gothenburg, 2008. http://hdl.handle.net/2077/18196.
Full text
16
Young, Gregory Scott. "The application of thermal microscopy, differential scanning calorimetry, and fourier transform infrared microspectroscopy to characterize deterioration and physiochemical change in fibrous Type 1 collagen." Thesis, University College London (University of London), 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.420072.
Full text
17
Rahal, Andrés. "Improved specificity of MRI diagnosis of collagenous lesions in tendon : a dissertation /." San Antonio : UTHSC, 2007. http://proquest.umi.com/pqdweb?did=1397911041&sid=1&Fmt=2&clientId=70986&RQT=309&VName=PQD.
Full text
18
LOCATELLI, LUIGI. "Expression of aVB6 integrin by Pkhd1-defective cholangiocytes links enhanced ductal secretion of Macrophage chemokines to progressive portal fibrosis in Congenital Hepatic Fibrosis." Doctoral thesis, Università degli Studi di Milano-Bicocca, 2013. http://hdl.handle.net/10281/41733.
Full textAbstract:
BACKGROUND AND AIMS: Congenital Hepatic Fibrosis (CHF) is caused by mutations in PKHD1, a gene encoding for fibrocystin, a protein of unknown function, expressed in cholangiocyte cilia and centromers. In CHF, biliary dysgenesis is accompanied by severe progressive portal fibrosis and portal hypertension. The mechanisms responsible for portal fibrosis in CHF are unclear. The αvβ6 integrin mediates local activation of TGFβ1 and is expressed by reactive cholangiocytes during cholestasis. To understand the mechanisms of fibrosis in CHF we studied the expression of αvβ6 integrin and its regulation in Pkhd1del4/del4 mice.
METHODS: In Pkhd1del4/del4 mice we studied, at different ages (1-12 months): a) portal fibrosis (Sirius Red) and portal hypertension (spleen weight/body weight); b) αvβ6 mRNA and protein expression (RT-PCR, IHC); c) α-SMA and TGFβ1 mRNA expression (RT-PCR); d) portal inflammatory infiltrate (IHC for CD45 and FACS analysis of whole liver infiltrate); f) cytokines secretion from cultured monolayers of primary cholangiocytes (Luminex assay); g) cytokine effects on monocyte/macrophage proliferation (MTS assay) and migration (Boyden chamber); h) TGFβ1 and TNFα effects on β6 integrin mRNA expression by cultured cholangiocytes before and after inhibition of the TGFβ receptor type II (TGFβRII); i) TGFβ1 effects on collagen type I (COLL1) mRNA expression by cultured cholangiocytes.
RESULTS: Pkhd1del4/del4 mice showed a progressive increase in αvβ6 integrin expression on biliary cyst epithelia. Expression of αvβ6 correlated with portal fibrosis (r=0.94, p<0.02) and with enrichment of a CD45+ve cell infiltrate in the portal space (r=0.97, p<0.01). Gene expression of TGFβ1 showed a similar age-dependent increase. FACS analysis showed that 50-75% of the CD45+ve cells were macrophages (CD45/CD11b/F4/80+ve). Cultured polarized Pkhd1del4/del4 cholangiocytes secreted from the basolateral side significantly increased amounts of CXCL1 and CXCL10 (p<0.05). Both cytokines were able to stimulate macrophage migration (p<0.05). Basal expression of β6 mRNA by cultured Pkhd1del4/del4 cholangiocytes (0.015±0.002 2^-dCt) was potently stimulated by the macrophage-derived cytokines TGFβ1 (0.017±0.002 2^-dCt, p<0.05) and TNFα (0.018±0.003 2^-dCt, p<0.05). Inhibition of TGFβRII completely blunted TGFβ1 (0.014±0.003 2^-dCt, p<0.05) but not TNFα effects (0.017±0.001 2^-dCt, p=ns) on β6 mRNA. COLL1 mRNA expression by cultured Pkhd1del4/del4 cholangiocytes (0.0009±0.0003 2^-dCt) was further and significantly increased after TGFβ1 stimulation (0.002±0.0005 2^-dCt, p<0.05).
CONCLUSIONS: Pkhd1del4/del4 cholangiocytes possess increased basolateral secretory functions of chemokines (CXCL1, CXCL10) able to orchestrate macrophage homing to the peribiliary microenvironment. In turn, by releasing TGFβ1 and TNFα, macrophages up-regulate αvβ6 integrin in Pkhd1del4/del4 cholangiocytes. αvβ6 integrin activates latent TGFβ1, further increasing the fibrogenic properties of cholangiocytes.
19
Fell, Cody Alexander. "Soft robotic devices for emulating vascular mechanobiology." Thesis, Queensland University of Technology, 2021. https://eprints.qut.edu.au/213109/1/Cody%20Alexander_Fell_Thesis.pdf.
Full textAbstract:
This thesis comprises two research projects undertaken as part of the dual biofabrication master's program between Queensland University of Technology and Utrecht University. The two projects focused on leveraging biofabrication, tissue-culture, and soft robotics to develop novel methods for fabricating 3D vascular and colon tissue, respectively. The first project developed a novel approach for conditioning cells using soft robotics that emulate vascular biomechanics, whereas the second project combined bioink micromoulding and melt electrospinning writing to fabricate 3D colon organoid constructs that mimic colon crypt morphology. Together, these projects contribute innovative biofabrication methods for creating tissue-culture models with enhanced biomimicry.
20
Hyry, M. (Marjo). "Lysyl hydroxylases 1 and 2:characterization of their in vivo roles in mouse and the molecular level consequences of the lysyl hydroxylase 2 mutations found in Bruck syndrome." Doctoral thesis, Oulun yliopisto, 2012. http://urn.fi/urn:isbn:9789514298424.
Full textAbstract:
Abstract The extracellular matrix is not just a scaffold for cells and tissues, but rather a dynamic part of the human body. Characteristics of collagens, the major protein components of the extracellular matrix, are determined already during synthesis and mutations in genes encoding collagens, unbalance of regulators or dysfunction of collagen modifying enzymes, for instance, can lead to severe clinical complications. Certain hydroxylysine residues formed by lysyl hydroxylases (LHs) function in collagens as precursors of collagen cross-links that stabilize collagenous structures and thereby tissues. In humans, a deficiency of LH1, which is known to hydroxylate lysines in the helical regions of collagen polypeptides, causes Ehlers-Danlos syndrome VIA (EDS VIA). It is characterized e.g. by progressive kyphoscoliosis and hypermobile joints. Mutations in LH2, which is known to hydroxylate lysines in the telopeptides of collagen polypeptides, cause Bruck syndrome type 2 (BS2). BS2 patients suffer from fragile bones and congenital joint contractures, for instance, but the syndrome is usually not lethal. In this work we have generated and analyzed genetically modified LH1 and LH2 null mouse lines to study the in vivo functions and roles of these enzymes. Analyses concentrated also on collagen cross-links that were determined from several null or heterozygous mouse tissues. In the present work we also studied the effects of known BS2 mutations on recombinant human LH2 polypeptides to understand the molecular pathology of the syndrome. As an animal model for human EDS VIA, LH1 null mice had certain characteristics typical for EDS VIA, such as muscular hypotonia, but generally the symptoms were milder. Like EDS VIA patients, the mice have an increased risk of arterial ruptures and ultrastructural changes can be seen in the wall of the aorta, explained by inadequate helical lysine hydroxylation accompanied by a changed cross-linking state of tissues. Similarly, analysis of the LH2 null mouse line demonstrated the importance of the enzyme in cross-link formation. We showed that even a reduced amount of LH2 in adult mice changes the cross-linking pattern in tissues and a total lack of the enzyme leads to embryonic lethality. Furthermore, we demonstrated that LH2 is particularly important in tissue structures supporting blood vessels in the developing mouse embryo or in extraembryonic tissues. Finally, our in vitro studies with recombinant human LH2 polypeptides revealed that the known BS2 mutations severely affect the activity of the enzyme thus explaining the clinical symptoms of the patients, but the mutations do not lead to a total inactivation of the enzyme, which may be critical for the survival of patientsTiivistelmä Solunulkoinen matriksi ei ole ainoastaan soluja ja kudoksia tukeva rakenne, vaan se on dynaaminen osa ihmiskehoa. Kollageenien, solunulkoisen matriksin yleisimpien proteiinien ominaisuudet määräytyvät jo kollageenien synteesivaiheessa ja mutaatiot kollageeneja koodittavissa geeneissä, säätelytekijöiden epätasapaino tai esimerkiksi kollageeneja muokkaavien entsyymien toimintahäiriöt voivat johtaa vaikeisiin kliinisiin komplikaatioihin. Tietyt lysyylihydroksylaasien (LH) muodostamat hydroksilysiinitähteet toimivat kollageeneissa kollageeniristisidosten esiasteina. Ristisidokset vakauttavat kollageenirakenteita ja siten myös kudoksia. LH1 hydroksyloi lysiinejä kollageenipolypeptidien kolmoiskierteisellä alueella ja ihmisellä entsyymin puutos aiheuttaa tyypin VIA Ehlers-Danlosin syndrooman (EDS VIA), jossa potilailla on esimerkiksi etenevää kyfoskolioosia ja yliliikkuvat nivelet. Mutaatiot LH2-entsyymissä, joka hydroksyloi lysiinejä kollageenipolypeptidien telopeptidialueilla, aiheuttavat tyypin 2 Bruckin syndrooman (BS2). BS2-potilaat kärsivät mm. luiden hauraudesta ja niveljäykkyydestä, mutta syndrooma ei yleensä ole letaali. Tässä työssä loimme ja analysoimme geneettisesti muunnellut LH1 ja LH2 hiirilinjat, joiden kyseinen LH-geeniaktiivisuus on hiljennetty. Linjojen avulla halusimme tutkia näiden entsyymien toimintaa ja merkitystä in vivo. Analyysit keskittyivät myös kollageeniristisidoksiin, joita tutkittiin useista poistogeenisten tai heterotsygoottisten hiirten kudoksista. Ymmärtääksemme BS2:n molekyylipatologiaa, tutkimme tässä työssä myös tunnettujen BS2-mutaatioiden vaikutuksia ihmisen LH2-rekombinanttiproteiinissa. EDS VIA:n eläinmallina LH1 poistogeenisillä hiirillä on joitakin ominaisuuksia, kuten lihashypotonia, jotka ovat tyypillisiä EDS VIA:lle, mutta yleisesti oireet ovat lievempiä. Kuten EDS VIA-potilailla, hiirillä on kohonnut valtimoiden repeytymisriski ja aortan seinämän ultrarakenteessa voidaankin havaita muutoksia. Oireita voidaan selittää riittämättömällä kollageenien kolmoiskierteisen alueen lysiinien hydroksylaatiolla, joka muuttaa kollageenien ristisidostilaa kudoksissa. Myös LH2-hiirilinjan analysointi osoitti kyseisen entsyymin tärkeyden ristisidosten muodostamisessa. Jo alentunut LH2:n määrä aikuisissa hiirissä muuttaa kudosten kollageeniristisidoksia ja täydellinen entsyymin puuttuminen johtaa sikiön kuolemaan. Lisäksi osoitimme, että LH2 on erityisen tärkeä kudosrakenteissa, jotka tukevat kehittyvän hiiren sikiön tai sikiön ulkopuolisten kudosten verisuonia. In vitro-tutkimukset ihmisen LH2-rekombinanttiproteiinilla paljastivat, että tunnetut BS2-mutaatiot vaikuttavat erittäin haitallisesti entsyymin toimintaan, mikä selittää potilaiden kliiniset oireet, mutta mutaatiot eivät kuitenkaan aiheuta entsyymin täydellistä inaktivaatiota, mikä voi olla kriittistä potilaiden selviytymisen kannalta
21
Yang, Yueh-Hsun. "Development of hydrodynamically engineered cartilage in response to insulin-like growth factor-1 and transforming growth factor-beta1: formation and role of a type I collagen-based fibrous capsule." Diss., Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/49072.
Full textAbstract:
Articular cartilage which covers the surfaces of synovial joints is designed to allow smooth contact between long bones and to absorb shock induced during joint movement. Tissue engineering, a means of combining cells, biomaterials, bioreactors and bioactive agents to produce functional tissue replacements suitable for implantation, represents a potential long-term strategy for cartilage repair. The interplay between environmental factors, however, gives rise to complex culture conditions that influence the development of tissue-engineered constructs. A fibrous capsule that is composed of abundant type I collagen molecules and resembles fibrocartilage usually forms at the outer edge of neocartilage, yet the understanding of its modulation by environmental cues is still limited. Therefore, this dissertation was aimed to characterize the capsule formation, development and function through manipulation of biochemical parameters present in a hydrodynamic environment while a chemically reliable media preparation protocol for hydrodynamic cultivation of tissue-engineered cartilage was established. To this end, a novel wavy-wall bioreactor (WWB) that imparts turbulent flow-induced shear stress was employed as the model system and polyglycolic acid scaffolds seeded with bovine primary chondrocytes were cultivated under varied biochemical conditions.
The results demonstrated that tissue morphology, biochemical composition and mechanical strength of hydrodynamically engineered cartilage were maintained as the serum content decreased by 80% (from 10% to 2%). Transient exposure of the low-serum constructs to exogenous insulin-like growth factor-1 (IGF-1) or transforming growth factor-β1 (TGF-β1) further accelerated their development in comparison with continuous treatment with the same bioactive molecules. The process of the capsule formation was found to be activated and modulated by the concentration of serum which contains soluble factors that are able to induce fibrotic processes and the capsule development was further promoted by fluid shear stress. Moreover, the capsule formation in hydrodynamic cultures was identified as a potential biphasic process in response to concentrations of fibrosis-promoting molecules such as TGF-β. Comparison between the capsule-containing and the capsule-free constructs, both of which had comparable tissue properties and were produced by utilizing the WWB system in combination with IGF-1 and TGF-β1, respectively, showed that the presence of the fibrous capsule at the construct periphery effectively improved the ability of engineered cartilage to integrate with native cartilage tissues, but evidently compromised its tissue homogeneity.
Characterization of the fibrous capsule and elucidation of the conditions under which it is formed provide important insights for the development of tissue engineering strategies to fabricate clinically relevant cartilage tissue replacements that possess optimized tissue homogeneity and properties while retaining a minimal capsule thickness required to enhance tissue integration.
22
Le, Cao cuong. "Rôle de LRP-1 dans la prolifération des cellules issues de cancer du côlon en matrice tridimensionnelle de collagène de type I." Thesis, Reims, 2020. http://www.theses.fr/2020REIMS026.
Full textAbstract:
Le récepteur low-density lipoprotein receptor-related protein-1 (LRP-1) est un récepteur d’endocytose multifonctionnel impliqué dans de nombreux processus physiologiques et pathologiques. Plusieurs études ont montré que LRP-1 joue un rôle crucial lors des processus de tumorigenèse et durant la progression tumorale, notamment en régulant l’expression de protéines membranaires. Des études antérieures ont montré l'implication des récepteurs du collagène de type I de la famille des Discoidin Domain Receptors (DDRs) dans la régulation de la prolifération des cellules cancéreuses en 3D. Le but de ce travail est d'étudier s’il existe une interaction fonctionnelle entre LRP-1 et DDR1 et si celle-ci pourrait moduler la prolifération des cellules de cancer colorectal (CRC) cultivées dans une matrice 3D de collagène de type I.Nos résultats ont permis de montrer qu'une invalidation de LRP-1 ou une inhibition de son activité par l’utilisation d’antagonistes sélectifs (RAP, anticorps bloquants) altère la prolifération des cellules de CRC LS174T et HT-29, uniquement lorsque qu’elles sont intégrées dans une matrice 3D de collagène de type I. De plus, la surexpression de DDR1-GFP dans les cellules HT-29 (HT-29DDR-GFP) diminue leur taux de croissance, tandis que l’inhibition de LRP-1 par RAP induit un arrêt du cycle cellulaire et une augmentation de l’apoptose dans les cellules HT-29 et HT-29DDR-GFP. Nous avons montré que la quantité de DDR1 à la surface cellulaire était augmentée et que l’endocytose de DDR1 était réduite de moitié lors du traitement par RAP, mettant ainsi en évidence une nouvelle voie d’internalisation pour DDR1. De plus, LRP-1 et DDR1 co-immunoprécipitent ensemble indiquant que ces récepteurs sont fortement associés au sein d’un même complexe moléculaire dans les cellules de CRC.Nos résultats mettent en évidence l’existence d’une interface fonctionnelle entre LRP-1 et DDR1 I soutenant la prolifération des cellules de CRC dans une matrice 3D de collagèneLow-density lipoprotein receptor related protein-1 (LRP-1) is a multifunctional endocytic receptor mediating the clearance of various molecules from the extracellular matrix, including metalloproteases and various glycoproteins. Several studies have shown that LRP-1 plays crucial roles in tumorigenesis and during tumor progression. LRP-1 also functions as a main regulator of signaling pathway by interacting with other cell-surface receptors. Previous studies have highlighted the involvement of Discoidin Domain Receptors (DDRs), type I collagen receptors with tyrosine kinase activity, in the regulation of cancer cell proliferation in 3D experimental models. The aim of this work is to study the potential functional interplay between LRP-1 and DDR1 in order to investigate whether this interaction may modulate the proliferation of colorectal cancer (CRC) cells in highly relevant 3D type I collagen matrices.In this study, we demonstrated that inhibition of LRP-1-mediated endocytosis using RNA interference or selective antagonists (RAP and R2629 blocking antibodies) impaired LS174T and HT-29 carcinoma cell proliferation, but only when embedded in a 3D collagen matrix. Using 3D cultures, DDR1-GFP overexpressing HT-29 (HT-29DDR-GFP) reduced the colorectal carcinoma cell growth rate, whereas RAP treatment led to cell cycle arrest and induced apoptosis in both HT-29 and HT-29DDR-GFP. By streptavidin/biotin-based immunoassays, we demonstrated that membrane-anchored DDR1 amount was increased upon RAP treatment while DDR1 uptake was reduced by a half upon LRP-1 inhibition, highlighting a new way for DDR1 internalization and dynamics. Consistently, co-immunoprecipitations confirmed the existence of a LRP1:DDR1 biomolecular complex at the cell surface of CRC cells.Our results suggest a role for LRP-1 in promoting CRC cell proliferation in 3D collagen environment by mediating DDR1 endocytosis
23
Guignel, Nadine Joëlle. "Skeletal Status and Bone Turnover in Overweight Young Men with and without Sleep Apnea Syndrome." Thesis, Virginia Tech, 2005. http://hdl.handle.net/10919/33725.
Full textAbstract:
Obesity is a worldwide epidemic increasing at an alarming rate among youth who are facing similar health problems as adults. Sleep Apnea Syndrome (SAS) is an underdiagnosed comorbidity of obesity, characterized by repetitive nocturnal interruptions in breathing. Obesity is associated with delayed skeletal maturation in overweight youth, but mechanisms contributing to this problem are unclear. Obesity and SAS both have been shown to disrupt regulatory hormones and cytokines that influence bone accretion during adolescence. PURPOSE: The purpose of this study was to assess the combined effects of excess body weight and SAS on bone mineral density (BMD) and content (BMC), bone turnover, and on the regulatory hormones leptin and IGF-1 known to potentially influence bone accretion during adolescence. METHODS: Men aged 18-28 years were assigned to groups as follows: normal weight controls (CON: AHI <3, n=8); overweight without SAS (OWT: BMI < 26 kg/m2 and AHI <3, n=9); and overweight with SAS (SAS: BMI >26 kg/m2 and AHI >5, n=8). The apnea/hypopnea index (AHI) expresses the score for disrupted nighttime breathing events/hr and was obtained in this study with results from a home sleep screening test. Health history and Epworth Sleepiness Scale (ESS) questionnaires also were administered. Bone mineral parameters and body composition variables were measured with dual-energy X-ray absorptiometry. Serum osteocalcin, leptin, IGF-1, and NTx-1 were measured, respectively, by radioimmunoassay and enzyme-linked immunoabsorbent assay. RESULTS: Fat-free mass, intra-abdominal fat, and fat mass were higher in the SAS and OWT groups (p<0.03). ESS scores revealed that SAS individuals were sleepier than CON and OWT groups (p<0.009). Total body and site-specific BMD and BMC values (lumbar spine, hip, and forearm) were similar between groups and did not relate to the estimated AHI score. Serum OC and NTx-1 did not differ between groups. Leptin levels were 30% higher in OWT and SAS than in the CON group (p<0.02), but did not correlate with the AHI score. Across all subjects (n=25), only lumbar spine BMC (p<0.005) was correlated to AHI (r=-.52; p<0.01). The preponderance of this relationship between AHI and lumbar spine BMC was attributable to the close inverse association of these two variables within the SAS group (r = -.81; p<0.001). CONCLUSION: The effects of SAS were not influenced by the amount of whole-body, intra-abdominal adiposity or lean body mass. Neither leptin nor IGF-1 predicted bone status across all groups. Daytime fatigue and sleepiness, a cardinal symptom of SAS, combined with overweight may contribute to lower lumbar BMC by chronically reducing weight-bearing physical activity and thereby reduce exposure time for mechanical loading of the spine in affected individuals. Further research is needed to explore the biochemical, physiological, and apparently the physical activity implications of SAS on skeletal status and turnover.Master of Science
24
Matsui, Yuto. "Visualization of procollagen IV reveals ER-to-Golgi transport by ERGIC-independent carriers." Kyoto University, 2020. http://hdl.handle.net/2433/259728.
Full text
25
POLITO, UMBERTO. "THE MENISCUS: BASIC SCIENCE TO IMPROVE KNOWLEDGE FOR TISSUE ENGINEERING." Doctoral thesis, Università degli Studi di Milano, 2020. http://hdl.handle.net/2434/707236.
Full textAbstract:
This thesis was thought with the intent to try to fill some lacunae in the knowledge of the anatomic-dependent features of the meniscus. In particular, the study of the effects of endogenous and exogenous factors upon the development of this structure will be outlined. Endogenous factors have been considered those factors that cannot be attributed to external or experimental factors: the effect of age and growth has been investigated focusing on the variation of the, matrix components (collagen types, GAGs and decorin), cellular phenotypic modifications and meniscal morpho-functional structure, with additional focus on possible differences presented in different animal models. On the other hand, exogenous factors have been considered those factors that are in any way attributable to the external interventions operated by the experimenter or by the application of forces upon meniscus. As exogenous factors, the effects of physiologic (compression and traction to which meniscus is naturally subjected) and non-physiologic (continuous compression without flexion) forces applied to meniscus during growth were evaluated. Furthermore, the effect of hypoxia in meniscal tissue-culture was also evaluated in a neonatal committed cell population in order to assess a faster maturation of the tissue. The importance of these investigations is linked to the possible application of these notions in the field of tissue engineering of the meniscus and may improve the current knowledge on the morpho-functional effect that external factors exercise on its structure.
26
Rizzato, Vanessa Rodrigues. "Envolvimento da neuraminidase-1 na atrofia muscular." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/5/5138/tde-01122014-094857/.
Full textAbstract:
Sialidose é uma doença neurossomática causada pela deficiência congênita da neuraminidase-1 (Neu1), enzima envolvida na regulação do catabolismo de sialoglicoconjugados nos lisossomos. Com o acúmulo de sialoglicoconjugados, ocorre comprometimento sistêmico e neurológico. Achados histológicos musculares incluem expansão da matriz extracelular (MEC) devido à proliferação anormal de fibroblastos, invasão das fibras musculares por componentes da MEC, fragmentação do citoplasma, formação vacuolar e atrofia das fibras musculares. Entretanto o mecanismo da atrofia muscular na deficiência de Neu1 não está completamente esclarecido, sendo o objetivo desse estudo. Desnervou-se o músculo gastrocnêmio direito de camundongos com deficiência de Neu1 (Neu1 -/-) e de controles Neu1 +/+. Os animais foram eutanasiados 0, 3, 7, 14 e 21 dias pós desnervação. Os músculos desnervados e contralaterais foram submetidos às seguintes análises: 1) histologia geral e medida da área transversa das fibras; 2) autofagia, através da avaliação da presença de vacúolos autofágicos por estudo ultraestrutural e da análise da expressão da proteína LC3; 3) ativação do sistema lisossomal, por reação de fosfatase ácida e análise da expressão proteica de catepsina L e lamp1; 4) deposição de colágeno e infiltração de tecido conjuntivo no tecido muscular; 5) níveis das proteínas Akt e GSK3b; 6) expressão dos atrogenes MuRF1 e Atrogina-1; 7) níveis da proteína MyoD, relacionada à diferenciação muscular; e 8) expressão dos genes Neu1, Neu2, Neu3 e Neu4. Os animais Neu1-/- apresentaram menor peso corporal e muscular compararando-se com animais Neu1 +/+. Houve redução progressiva da área das fibras dos músculos desnervados em relação aos músculos contralaterais. Os animais Neu1-/- apresentaram atrofia muscular basal, com aumento acentuado dos espaços endomisiais e perimisiais. Ocorreu formação de vacúolos autofágicos a partir de 14 dias de desnervação tanto em animais Neu1+/+ quanto em Neu1-/-. Os níveis de expressão proteica de catepsina L e de lamp1 aumentaram a partir de 14 dias de desnervação, mais notadamente em músculos desnervados de camundongos Neu1-/-. A expressão proteica de colágeno III mostrou-se aumentada em animais Neu1-/-, principalmente após desnervação. A expressão proteica da forma fosforilada do Akt (forma ativada) diminuiu após 21 dias de desnervação principalmente em músculos desnervados de animais Neu1+/+. Os níveis de PGSK3 b, forma inativa de GSK3b, diminuíram após a desnervação, em animais Neu1+/+ e animais Neu1-/-. Houve aumento na expressão gênica de Atrogina-1 e MuRF1 após 3 e 7 dias de desnervação, respectivamente; a expressão gênica de Atrogina-1 nos camundongos Neu1-/- teve um aumento atrasado, mostrando diferença significante após 7 dias de desnervação. Não houve diferença significativa entre níveis proteicos de MyoD. A expressão gênica de Neu1 mostrou-se elevada em músculos desnervados de animais Neu1+/+. Conclui-se, portanto, que a Neu1 parece atuar na regulação da massa muscular principalmente controlando o processo de ativação do sistema lisossomal, porém aparentemente sem afetar a autofagiaSialidosis, a severe neurosomatic disease, results from congenital neuraminidase-1 (Neu1) deficiency. This enzyme regulates the catabolism of sialoglycoconjugates in the lysosomes. Systemic and neurologic manifestations occur due to the sialoglycoconjugates accumulation. In the mouse model for Neu1 deficiency, the muscle histologic findings include extracellular matrix (ECM) expansion, due to abnormal fibroblast proliferation, muscle fibers invasion by ECM components, cytoplasm fragmentation, vacuolar formation and muscle atrophy. Nevertheless the mechanisms of muscle atrophy in Neu1 deficiency are not completely known. This study was designed to investigate Neu1 involvement in muscle atrophy process. Denervation of gastrocnemius muscle was performed by sectioning sciatic nerve from Neu1 deficient mice (Neu1 -/-) and from normal control Neu1 +/+; the animals were euthanized 0, 3, 7, 14 and 21 days after denervation. Denervated and control muscles were collected and submitted to several analysis: 1) histological; 2) autophagic vacuoles formation, performed by ultrastructural analysis and LC3 protein expression; 3) acid phosphatase reaction, lamp1 and cathepsin L protein expression, to analyze lysosomal activation; 4) collagen deposition and fibrous formation; 5) proteins involved with muscle trophism, Akt and GSK3b; 6) MuRF1 and Atrogin-1 gene expression; 7) MyoD protein expression; 8) Neu1, Neu2, Neu3 and Neu4 genes expression. Neu1 -/- mice presented decreased body and muscle weight comparing to Neu1 +/+ animals. Muscle fiber cross-sectional area was reduced in denervated muscles comparing to contralateral muscles. Neu1 -/- mice muscles presented basal atrophy and increase of endomisial and perimisial spaces, which became more evident after denervation. After 14 days of denervation, autophagosome formation was noticed on Neu1 +/+ and Neu1-/- animals. Cathepsin L protein levels were increased after 14 and 21 days of denervation, especially in denervated muscles from Neu1 -/- mice. Lamp1 protein expression was increased in Neu1-/- animals. Type III collagen protein levels were increased in Neu1-/- animals. There were no significant differences between MyoD protein levels. P-Akt, active form of Akt protein levels, decreased after 21 days of denervation, especially in denervated muscles from control group animals, indicating that protein synthesis is decreased. P-GSK3b, inactive form of GSK3b decreased in denervated muscles from Neu1 -/- and Neu1 +/+ animals, which indicates that this protein remained activated during muscle atrophy process. There were significant differences in Atrogin-1 and MuRF1 gene expression levels after 3 and 7 days of denervation. Neu1 -/- animals muscles presented a delayed Atrogin-1 response. Neu1 gene expression was increased in denervated muscles from Neu1 +/+ mice. These findings suggest that Neu1 seems to act in the regulation of muscle mass mainly by controlling the process of lysosomal system activation, but apparently without affecting autophagy
27
Kanno, Cláudia Misue. "Efeitos da ciclosporina, fenitoína e nifedipina sobre a síntese e degradação de colágeno da gengiva de macacos-prego (Cebus apella) : estudo histoquímico e através de RT-PCR /." Araçatuba : [s.n.], 2006. http://hdl.handle.net/11449/102345.
Full textAbstract:
Orientador: Alvimar Lima de CastroBanca: Renata Tucci
Banca: José Fernando Garcia
Banca: Sérgio Roberto Peres Line
Banca: José Américo de Oliveira
Resumo: INTRODUÇÃO: As alterações em gengiva induzidas por medicamentos têm sido pouco estudadas quanto à expressão in vivo dos genes das metoloproteinases (MMPs). O objetivo do presente trabalho foi avaliar o padrão histológico de distribuição de fibras colágenas após a administração de ciclosporina, nifedipina ou fenitoína e correlacionar com a expressão dos genes do colágeno do tipo I, MMP-1 e MMP2. MATERIAL E MÉTODO: Amostras da gengiva da área de canino superior direito foram obtidas de doze macacos prego (Cebus apella) machos. A extremidade mesial de cada amostra foi imediatamente congelada em nitrogênio líquido enquanto que a distal foi processada para inclusão em parafina. Após uma semana, os animais foram divididos em três grupos que receberam doses diárias de ciclosporina, fenitoína ou nifedipina, durante 120 dias. Procedeu-se à remoção de amostras da gengiva da área do canino superior esquerdo de dois animais de cada grupo aos 52 e 120 dias. Os cortes histológicos foram corados pelas técnicas da hematoxilina e eosina, vermelho picrosirius, além da marcação imunoistoquímica para colágeno do tipo IV. O RT-PCR semiquantitativo foi realizado para se determinar os níveis de mRNA. RESULTADOS: No grupo controle, houve o predomínio de fibras colágenas maduras, evidenciadas com a cor vermelha em cortes corados pela técnica do vermelho picrosirius analisados com microscópio de luz polarizada. Observou-se nos grupos tratados aos 52 e 120 dias um aumento da porcentagem de áreas ocupadas por fibras imaturas, em todos os grupos, independentemente da idade do animal. No entanto, não foram observadas diferenças morfológicas entre os grupos controle e tratado nos cortes corados pela hematoxilina e eosina. Houve uma tendência a valores médios mais baixos ...(Resumo completo, clicar acesso eletrônico abaixo)
Abstract: Background: Few studies have focused on the in vivo expression of matrix metalloproteinase (MMP) genes in gingival changes induced by drugs. The aim of the present study was to evaluate the histological pattern of collagen fiber distribution after phenytoin, cyclosporine or nifedipine medication and correlate with collagen type 1, MMP-1 and MMP-2 gene expression levels. Methods: Gingival samples were obtained from superior right canine area of twelve male capuchin monkeys (Cebus apella). The mesial part of the biopsy specimens was immediately frozen in liquid nitrogen, while the distal one was processed for paraffin inclusion. One week after the control biopsy, the animals were divided in three groups that received daily doses of cyclosporine, phenytoin or nifedipine during 120 days. Gingival samples were obtained from left superior canine area on 52nd and 120th day of treatment (two animal of each experimental group). Histologic sections were subjected to hematoxylin and eosin, picrosirius red stainings, and to immunohistochemical reaction for collagen type IV. MMP-1, MMP-2 and collagen type I mRNA levels were determined by RT-PCR. Results: Predominance of mature collagen fibers was observed in the control group after picrosirius red staining, visualized as red fibers under polarized microscope. Increased percentage of areas occupied by immature collagen fibers was observed on 52 and 120 experimental periods, in all groups, despite the animal age. However, no morphological differences between treated and control groups were observed on hematoxilin and eosin stained sections. There was a trend to lower levels of MMP-1 expression on 52-day samples. However, MMP-2 and collagen type I gene expressions seemed to be phased and drug-related. Conclusions: The results allowed the ...(Complete abstract click electronic access below)
Doutor
28
Kanno, Cláudia Misue [UNESP]. "Efeitos da ciclosporina, fenitoína e nifedipina sobre a síntese e degradação de colágeno da gengiva de macacos-prego (Cebus apella): estudo histoquímico e através de RT-PCR." Universidade Estadual Paulista (UNESP), 2006. http://hdl.handle.net/11449/102345.
Full textAbstract:
Made available in DSpace on 2014-06-11T19:32:06Z (GMT). No. of bitstreams: 0
Previous issue date: 2006-03-27Bitstream added on 2014-06-13T20:22:59Z : No. of bitstreams: 1
kanno_cm_dr_araca.pdf: 1730975 bytes, checksum: 620b9c72f44529033f574688f3ea9bde (MD5)INTRODUÇÃO: As alterações em gengiva induzidas por medicamentos têm sido pouco estudadas quanto à expressão in vivo dos genes das metoloproteinases (MMPs). O objetivo do presente trabalho foi avaliar o padrão histológico de distribuição de fibras colágenas após a administração de ciclosporina, nifedipina ou fenitoína e correlacionar com a expressão dos genes do colágeno do tipo I, MMP-1 e MMP2. MATERIAL E MÉTODO: Amostras da gengiva da área de canino superior direito foram obtidas de doze macacos prego (Cebus apella) machos. A extremidade mesial de cada amostra foi imediatamente congelada em nitrogênio líquido enquanto que a distal foi processada para inclusão em parafina. Após uma semana, os animais foram divididos em três grupos que receberam doses diárias de ciclosporina, fenitoína ou nifedipina, durante 120 dias. Procedeu-se à remoção de amostras da gengiva da área do canino superior esquerdo de dois animais de cada grupo aos 52 e 120 dias. Os cortes histológicos foram corados pelas técnicas da hematoxilina e eosina, vermelho picrosirius, além da marcação imunoistoquímica para colágeno do tipo IV. O RT-PCR semiquantitativo foi realizado para se determinar os níveis de mRNA. RESULTADOS: No grupo controle, houve o predomínio de fibras colágenas maduras, evidenciadas com a cor vermelha em cortes corados pela técnica do vermelho picrosirius analisados com microscópio de luz polarizada. Observou-se nos grupos tratados aos 52 e 120 dias um aumento da porcentagem de áreas ocupadas por fibras imaturas, em todos os grupos, independentemente da idade do animal. No entanto, não foram observadas diferenças morfológicas entre os grupos controle e tratado nos cortes corados pela hematoxilina e eosina. Houve uma tendência a valores médios mais baixos...
Background: Few studies have focused on the in vivo expression of matrix metalloproteinase (MMP) genes in gingival changes induced by drugs. The aim of the present study was to evaluate the histological pattern of collagen fiber distribution after phenytoin, cyclosporine or nifedipine medication and correlate with collagen type 1, MMP-1 and MMP-2 gene expression levels. Methods: Gingival samples were obtained from superior right canine area of twelve male capuchin monkeys (Cebus apella). The mesial part of the biopsy specimens was immediately frozen in liquid nitrogen, while the distal one was processed for paraffin inclusion. One week after the control biopsy, the animals were divided in three groups that received daily doses of cyclosporine, phenytoin or nifedipine during 120 days. Gingival samples were obtained from left superior canine area on 52nd and 120th day of treatment (two animal of each experimental group). Histologic sections were subjected to hematoxylin and eosin, picrosirius red stainings, and to immunohistochemical reaction for collagen type IV. MMP-1, MMP-2 and collagen type I mRNA levels were determined by RT-PCR. Results: Predominance of mature collagen fibers was observed in the control group after picrosirius red staining, visualized as red fibers under polarized microscope. Increased percentage of areas occupied by immature collagen fibers was observed on 52 and 120 experimental periods, in all groups, despite the animal age. However, no morphological differences between treated and control groups were observed on hematoxilin and eosin stained sections. There was a trend to lower levels of MMP-1 expression on 52-day samples. However, MMP-2 and collagen type I gene expressions seemed to be phased and drug-related. Conclusions: The results allowed the ...(Complete abstract click electronic access below)
29
Ivanoff, Jyrki. "Migration on extracellular matrix surface and infiltration into matrix - two distinguishable activities of human T cells." Doctoral thesis, Umeå University, Clinical Microbiology, 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-159.
Full textAbstract:
Migration of T-lymphocytes on a surface coated with extracellular matrix (ECM) components (two-dimensional (2-D) migration) and migration (infiltration) into a matrix (Three-dimesional (3-D) migration) are complex events and the underlying mechanisms are not yet fully understood. Here 2-D and 3-D migration were studied by use of seven leukemic T-cell lines representing discrete differentiation stages, a non-leukemic T-cell clone, and normal peripheral blood T cells. peripheral blood lymphocytes and the T-cell clone produced nanogram quantities of various chemokines, as compared to a production of ≤ 0.05 ng/ml by the T leukemia cell lines. In a Boyden chamber system, the leukemic T-cell lines showed haptotactic migration on fibronectin. The migration was augmented bu exposure to chemokines, including RANTES, MIP-1α, MIP-1β, and IL-8. The T-cell lines showed a peak response at a chemokine concentration of 10-50 ng/ml, whereas the T-cell clone responded optimally at 100 ng/ml. In contrast to a general capability of T-cells to migrate on 2-D ECM, only some of the T-cell lines were capable of 3-D migration into Matrigel or a collagen matrix. The infiltrative capacity was unrelated to the capacity to migrate on or adhere to the substrata. T-cell lines with a capacity to infiltrate produced matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of matrix metalloproteinases-1 (TIMP-1), whereas non-infiltrating cell lines did not produce MMP-9. T-cell lines capable of infiltrating Matrigel or collagen responded to chemokines exposure with increased infiltration, but the chemokines did not render non-infiltrative cell lines infiltrative. Stimulation of infiltration of T-cell lines into collagen by the chemokine SDF-1α was inhibited by somatostatin, a neuropeptide with immunosuppressive properties. In conclusion, the ability to migrate on 2-D substrata and to infiltrate into 3.D substrata was found to be distinguishable properties of T cells. failure of some T-cell lines to infiltrate correlated with the lack of expression of MMP-9. Chemokines stimulated infiltration of infiltrative T-cell lines into collagen and Matrigel but did not render non-infiltrative T-cell lines infiltrative. Finally, a possible physiological mechanism for modulation of the chemokine-stimulated 3-D migration was demonstrated.
30
Gonçalves, Fernanda Magalhães. "Efeitos do LDL oxidado em macrófagos M2. Implicações na aterosclerose." Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/5/5146/tde-29112017-101149/.
Full textAbstract:
A aterosclerose é uma doença crônica onde duas características marcantes são observadas: retenção de lipídios e inflamação. Compreender as interações entre as células do sistema imunológico e as lipoproteínas envolvidas na aterogênese são desafios urgentes, uma vez que as doenças cardiovasculares são a principal causa de morte no mundo. Os macrófagos são cruciais para o desenvolvimento de placas ateroscleróticas e para a perpetuação da inflamação em tais lesões; estas células também estão diretamente envolvidas na ruptura de placa instável. Recentemente diferentes populações de macrófagos estão sendo identificadas nas lesões ateroscleróticas. Embora macrófagos M2 tenham sido identificados, a função destas células na aterosclerose ainda não está definida. Neste projeto, avaliamos se a adição de LDLox altera a função de macrófagos M2. Resultados: 1- Foi possível observar que os M2 se mantem viáveis após o estímulo com as lipoproteínas. 2- Quando avaliamos a expressão de moléculas co-estimulatórias, receptores Scavenger, lectinas e integrinas na superfície das células, observamos que a adição de LDLn ou LDLox em 2 concentrações diferentes (5 e 50ug/ml), por diferentes períodos de tempo não alterou a expressão de nenhum dos marcadores avaliados. A presença de LDL também não alterou outra função primordial dos M2, a capacidade de fagocitose. 3- Quando investigamos a presença de citocinas no sobrenadante das culturas estimuladas ou não com as lipoproteínas, identificamos um aumento na secreção de IL-8, uma citocina pró-inflamatória, na presença de LDLox, semelhante ao observado com a população de macrófagos M1. 4- Avaliamos se os macrófagos M2 estimulados ou não com LDL mantem sua capacidade de favorecer a angiogênese. Observamos que nas culturas estimuladas com o sobrenadante das culturas dos M2 mantidos na presença de LDLox houve uma inibição significativa da formação de túbulos pelas HUVECs. 5- Observamos que na presença do meio condicionado dos M2 estimulados com LDLox ocorreu uma intensa degradação dos filamentos de matriz extracelular produzida por MEFs. 6- Avaliamos a expressão gênica de componentes de matriz, membrana basal, moléculas de adesão, proteases e também inibidores de protease nestas células. Dos 96 genes avaliados, observamos que a adição de LDLox reduziu a expressão de 10 genes de maneira significativa, entre eles: beta-Actina (ACTB), Colágeno 6A2 (Col6A2), Integrina alfa 6 (ITGA6), Metaloproteinase 15 (MMP15), molécula de adesão celular endotelial plaquetária (PECAM) e Inibidor de metalopeptidase 2 (TIMP2). A adição de LDLox aumentou significativamente somente a expressão de trombospondina (TSP1). A adição de LDLn não alterou a expressão de nenhum gene de forma significativa. 7- A adição de LDLox induziu aumento da expressão da TSP1 e redução da expressão de colágeno 6, quando comparadas aos macrófagos M2 sem estímulo. Nossos resultados indicam que a adição de LDLox altera diversas funções dos macrófagos M2 in vitro. Em especial detectamos uma inibição significativa na angiogênese e também a secreção de mediadores que induzem a degradação da matriz extracelular. A adição de LDLox também inibiu a expressão de genes envolvidos com a estabilização da matriz extracelular. Nossos resultados sugerem que esta população de células pode contribuir para a perpetuação do processo inflamatório e degradação tecidual observados na lesão dos pacientes. Assim, acreditamos que este projeto contribuiu para o esclarecimento da participação dos M2 na patologia da ateroscleroseAtherosclerosis is a chronic disease where two key characteristics are observed: lipid retention and inflammation. Understanding the interactions between the cells of the immune system and the lipoproteins involved in atherogenesis are urgent challenges, since cardiovascular diseases are the leading cause of death in the world. Macrophages are crucial for the development of atherosclerotic plaques and for the inflammation in such lesions; These cells are also directly involved in unstable plaque rupture. Recently different populations of macrophages are being identified in atherosclerotic lesions. Although M2 macrophages has been identified, the function of these cells in atherosclerosis has not yet been defined. This project, we evaluated whether the addition of OxLDL alters the function of M2 macrophages. Results: 1- M2 macrophages remain viable after stimulation with the lipoproteins. 2- When evaluated the expression of co-stimulatory molecules, Scavenger receptors, lectins and integrins on the surface of the cells. We observed that the addition of LDLn or OxLDL at 2 different concentrations (5 and 50 ?g / ml) for different time periods did not alter the expression of any of the evaluated markers. 3- The presence of LDL also did not alter other primordial function of M2 cells, phagocytosis. 4- Was observed that cultures stimulated with conditioned medium of OxLDL-stimulated M2 there was a significant inhibition of tubule formation by HUVECs. 5- We observed that in the presence of OxLDL-stimulated M2 cells conditioned médium an intense degradation of the matrix filaments occurred. 6- We evaluated the gene expression of matrix components, basement membrane, adhesion molecules, proteases and also protease inhibitors in these cells. Of the 96 evaluated genes, we observed that the addition of OxLDL significantly reduced the expression of 10 genes, among them: Actin-beta (ACTB), Collagen 6A2 (Col6A2), Integrin alfa 6 (ITGA6), Metaloproteinase 15 (MMP15), Platelet endothelial cell adhesion molecule (PECAM) and metallopeptidase 2 inhibitor (TIMP2). The addition of OxLDL significantly increased only the expression, thrombospondin-1 (TSP1). Addition of LDLn did not significantly alter the expression of any gene. 7- That OxLDL addition induced increased TSP1 expression and reduced collagen 6 expression, when compared to M2 macrophages without stimulation. Our results indicate that the addition of OxLDL alters several M2 macrophages functions in vitro. In particular we detected a significant inhibition in angiogenesis and also the secretion of mediators that induce the degradation of the extracellular matrix. The addition of OxLDL also inhibited the expression of genes involved in extracellular matrix stabilization. Our results suggest that this cell population may contribute to the perpetuation of the inflammatory process and tissue degradation observed in the lesion of the patients. Thus, we believe that this project contributed to better understand the participation of M2 in the pathology of atherosclerosis
31
Urzel, Vanessa. "Apport de la résonance magnétique nucléaire des solides à la caractérisation chimique et à la datation des os en anthropologie médico-légale." Thesis, Bordeaux, 2014. http://www.theses.fr/2014BORD0019/document.
Full textAbstract:
L’estimation du délai post mortem est une étape fondamentale en anthropologie médico-légale. À ce jour, peu de méthodes précises et fiables existent. Les objectifs de notre travail étaient d’étudier le tissu osseux et son évolution dans les années et siècles suivant le décès en développant la Résonance Magnétique Nucléaire (RMN) des solides du carbone13C et du proton1H. Nous avons analysé une centaine d’os humains et animaux pour lesquels nous connaissions l’âge au décès, le sexe, la date de décès et les conditions de conservation. Nous avons caractérisé les os au niveau moléculaire en identifiant le collagène, les lipides et l’hydroxyapatite constitutifs du tissu osseux. Nous avons développé une méthode RMN permettant de distinguer des altérations de certains échantillons attestant de la présence d’adipocire au sein du tissu osseux, ou des dégradations sur des échantillons très anciens. L’étude de l’âge au décès et du sexe des sujets n’a pas mis en évidence une grande influence de ces facteurs sur les données RMN même si, pour des délais post mortem de 0 ou 1 an, les sujets féminins présentent quantitativement plus de lipides que les sujets masculins. L’analyse des conditions de conservation des individus montre un développement plus important d’adipocire pour les os laissés à l’air libre comparés aux os enterrés. Enfin, nous rapportons une décroissance quantitative du collagène et des lipides présents au sein du tissu osseux lorsque l’intervalle post mortem augmente. Cette décroissance est beaucoup plus rapide pour les lipides (quelques années) que pour le collagène (plusieurs millénaires) alors que l’hydroxyapatite présente une relative stabilité dans les premiers siècles suivant le décèsThe post mortem interval estimation is a fundamental step in forensic anthropology and up to now there are little accurate and reliable methods to do so. The objectives of our study were to investigate the bone composition and its evolution over years and centuries following the death by developing carbon 13C and proton 1H solid-state nuclear magnetic resonance (NMR). We analyzed about one hundred human and animal bones for which the age at death, sex, date of death and the storage conditions were known. Bones were characterized at the molecular level by identification of collagen, lipids and hydroxyapatite embedded in the bone matrix. We have designed a NMR-based method that allows determining alterations on some samples, evidencing the presence of adipocere (bone wax) within the bone, or finding bone tissue deterioration on some very old samples. Subject age at death and sex did not reveal significant changes on NMR data, except for post mortem interval ranging between 0 to 1 year, where female subjects had quantitatively more lipids in their bones than males. Storage conditions may promote a greater development of adipocere especially for bones left in the open air compared to those buried. Finally, we report a quantitative decrease of collagen and lipids present in the bone tissue when the post mortem interval increases. This decrease is much faster for lipids than for collagen where as the hydroxyapatite has a relative stability in the first centuries after the death. Decreases occur with very different time constants, ranging from years to millennia
32
Ferreira, Yuri Afonso. "Análise da expressão das metaloproteinases e seus inibidores teciduais no músculo detrusor de pacientes com obstrução infravesical por hiperplasia prostática benigna." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/5/5153/tde-13012015-111245/.
Full textAbstract:
Introdução: A obstrução infravesical (OIV) de longo prazo secundária a hiperplasia prostática benigna (HPB) pode causar alterações funcionais e morfológicas na bexiga. Um dos principais eventos consiste no aumento da deposição de colágeno e perda de complacência vesical, levando a alteração de armazenamento e esvaziamento urinário. O aumento da deposição de colágeno na matriz extracelular (MEC) da musculatura detrusora é a principal razão para a diminuição da complacência vesical. Na bexiga, assim como em outros órgãos, este fenômeno depende da atividade equilibrada de enzimas proteolíticas, incluindo as metaloproteinases (MMP) e os seus inibidores endógenos (inibidores teciduais de metaloproteinases-TIMPs). Como estes fenômenos são desconhecidos na bexiga obstruída, o objetivo deste estudo foi avaliar a expressão gênica de colágeno, MMPs e seus inibidores na bexiga de pacientes com obstrução infravesical. Material e Métodos: Foi realizada uma análise prospectiva e controlada de 43 pacientes com OIV devido a HPB, que foram submetidos à ressecção transuretral da próstata (RTUP) entre 2011 e 2012. Como grupo controle foram selecionados espécimes de músculo detrusor de 10 pacientes que foram submetidos a prostatectomia radical retropúbica devido adenocarcinoma de próstata. Todos estes pacientes tinham idade menor que 60 anos, tamanho de próstata menor que 30 gramas ao ultra-som e escore internacional de sintomas prostáticos (IPSS) menor que 7. Todos os pacientes foram submetidos a estudo urodinâmico pré e pós operatório (após 6 meses). A biópsia de fragmento de músculo da bexiga foi realizada ao final da RTUP e colocada em solução estabilizadora de RNA para quantificação da expressão de colágenos I e III, metaloproteinases de matriz 1, 2 e 9, e inibidores de MMPs (TIMP1, TIMP2 e RECK) na bexiga de pacientes com HPB. Os genes descritos foram avaliados através da técnica de reação em cadeia da polimerase quantitativa em tempo real (qRT-PCR). Resultados: Todos os pacientes com HPB tinham confirmado OIV, através da análise do estudo urodinâmico (média de pressão detrusora no fluxo máximo de 78,5 cmH2O e fluxo urinário máximo de 7,7 ml / s). O gene MMP1 mostrou-se superexpresso em pacientes com HPB (mediana = 1,87). MMP9, TIMP1 e RECK estavam subexpressos na maioria dos casos, enquanto TIMP2, colágeno I e III foram superexpressos (1,5, 4,4 e 1,9 vezes, respectivamente). No que diz respeito às características clínicas e urodinâmicas encontramos que MMP2 foi mais expresso entre pacientes com um baixo IPSS global (0,005) e sem urgência (p=0,035). Colágeno III foi mais expresso em pacientes com contrações vesicais não inibidas (p = 0,049). Os outros genes não mostraram nenhuma correlação estatística com quaisquer características clínicas ou urodinâmicas. Após 6 meses de RTU, pacientes que possuíam expressão aumentada de duas ou mais MMPs, apresentaram resolução da CNI em 66,6% dos casos, contra 14,0% quando apenas uma ou nenhuma MMP estava aumentada (p=0,038) Conclusões: Encontramos um perfil de superexpressão de MMP1, TIMP2, colágenos I e III, e expressão baixa de MMP9, TIMP1 e RECK nos pacientes com OIV. Considerando o escore de sintomas prostáticos e a urgência miccional, encontramos curiosamente uma maior expressão de MMP2 em pacientes menos sintomáticos e sem urgência miccional. Encontramos uma associação entre a maior expressão de colágeno III com HD. A expressão aumentada de duas ou mais MMPs está relacionada à maiores taxas de resolução das CNIs.Introduction: Long-term Bladder outlet obstruction (BOO) secondary to Benign prostatic Hyperplasia (BPH) can cause functional and morphological abnormalities in the bladder, such as increased collagen deposition and loss of compliance, leading to urinary storage and voiding symptoms. A decrease in bladder compliance is known to be correlated with deterioration of renal function. Increased deposition of collagen in the extracellular matrix (ECM) is the primary reason for a decreased compliance. In the bladder, as in other organs, this phenomenon is dependent on the balanced activity of proteolytic enzymes, including matrix metalloproteinases (MMPs) and their endogenous inhibitors, tissue inhibitors of metalloproteinases (TIMPs). The imbalance between MMPs and TIMPs is a key regulator in ECM turnover. Since these mechanisms are unknown in the obstructed bladder, the objective of this study was to evaluate gene expression of collagen, MMPs and their inhibitors in patients with bladder outlet obstruction due to BPH. Material and Methods: We performed a prospective and controlled analysis of 43 patients with BOO due to BPH who underwent transurethral resection of the prostate (TURP) from 2011 to 2012. The control group was comprised of 10 bladder specimens from patients with < 60 years who underwent radical prostatectomy with an International Prostatic Symptom Score (IPSS) < 8 and prostate volume < 30 grams. All patients underwent urodynamic analysis pre and post operatively after 6 months. A biopsy of the bladder muscle was performed at the end of TURP for analysis of collagen, metalloproteinases and TIMPs gene expressions. For this purpose we used the quantitative real time polymerase chain reaction method (qRT-PCR). Results: All patients with BPH had confirmed BOO confirmed through urodynamic analysis (mean detrusor pressure at maximun flow 78.5 cmH2O and mean maximun flow 7.7 ml/s). MMP1 gene showed an important an overexpression in patients with BPH (median = 1.87). A similar phenomenon occurred in a lesser extent to MMP2, to which 13 of 23 subjects had under-expression (mean = 1.2). MMP9, TIMP1 and RECK were under-expressed in the majority of cases, while TIMP2, colagen I and III were over-expressed (1.5, 4.4 and 1.9x respectively) (figure). With regard to clinical and urodynamic characteristics we found that MMP2 was more over-expressed among patients with a low global IPSS (0.005) and without urgency (p=0.035). Colagen III was more over-expressed in patients with non-inhibited bladder contractions (p=0.049), RECK was more over-expressed in patients with a decreased complacence (p=0.049). The other genes showed no statistical correlation with any clinical or urodynamic characteristics. After 6 months of TURP, patients with non-inhibited bladder contractions showed resolution in 66.6% of cases, when had increased expression of two or more (> 02) MMPs in patients compared with 14.0% when only 01 MMP was increased (p = 0.038) Conclusions: BOO is related with an over-expression of MMP1, TIMP2, colagens I and III, and with an under-expression of MMP9, TIMP1 and RECK. Detrusor overactivity is related with higher collagen III expression, this fact may be due to a lower MMP1 expression. A lower global IPSS and no urgency were related to a higher expression of MMP2, sugesting that this gene may be inhibiting collagen deposition in the bladder. The increased expression of two or more MMPs isrelated to greater rates of resolution of non-inhibited bladder contractions
33
Lusito, E. "A Network-based Approach to Breast Cancer Systems Medicine." Doctoral thesis, Università degli Studi di Milano, 2015. http://hdl.handle.net/2434/265572.
Full textAbstract:
Breast cancer is the most commonly diagnosed cancer and the second leading cause of cancer death in women. Although recent improvements in the prevention, early detection, and treatment of breast cancer have led to a significant decrease in the mortality rate, the identification of an optimal therapeutic strategy for each patient remains a difficult task because of the heterogeneous nature of the disease. Clinical heterogeneity of breast cancer is in part explained by the vast genetic and molecular heterogeneity of this disease, which is now emerging from large-scale screening studies using “-omics” technologies (e.g. microarray gene expression profiling, next-generation sequencing). This genetic and molecular heterogeneity likely contributes significantly to therapy response and clinical outcome. The recent advances in our understanding of the molecular nature of breast cancer due, in particular, to the explosion of high-throughput technologies, is driving a shift away from the “one-dose-fits-all” paradigm in healthcare, to the new “Personalized Cancer Care” paradigm. The aim of “Personalized Cancer Care” is to select the optimal course of clinical intervention for individual patients, maximizing the likelihood of effective treatment and reducing the probability of adverse drug reactions, according to the molecular features of the patient. In light to this medical scenario, the aim of this project is to identify novel molecular mechanisms that are altered in breast cancer through the development of a computational pipeline, in order to propose putative biomarkers and druggable target genes for the personalized management of patients. Through the application of a Systems Biology approach to reverse engineer Gene Regulatory Networks (GRNs) from gene expression data, we built GRNs around “hub” genes transcriptionally correlating with clinical-pathological features associated with breast tumor expression profiles. The relevance of the GRNs as putative cancer-related mechanisms was reinforced by the occurrence of mutational events related to breast cancer in the “hub” genes, as well as in the neighbor genes. Moreover, for some networks, we observed mutually exclusive mutational patterns in the neighbors genes, thus supporting their predicted role as oncogenic mechanisms. Strikingly, a substantial fraction of GRNs were overexpressed in Triple Negative Breast Cancer patients who acquired resistance to therapy, suggesting the involvement of these networks in mechanisms of chemoresistance. In conclusion, our approach allowed us to identify cancer molecular mechanisms frequently altered in breast cancer and in chemorefractory tumors, which may suggest novel cancer biomarkers and potential drug targets for the development of more effective therapeutic strategies in metastatic breast cancer patients.
34
Wan-Hsuan, Tung, and 董宛璇. "The Role of Rac1/MLK3/JNK/AP-1 in CTGF-Induced Type I Collagen Expression in Lung Fibroblasts." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/53899417254003645945.
Full textAbstract:
碩士臺北醫學大學
醫學科學研究所
98
Several evidences suggest that connective tissue growth factor (CTGF) overproduction underlies the development of lung fibrosis. Development of lung fibrosis is characterized by excessive deposition of collagens in the lung interstitium. Mixed linage kinase 3 (MLK3) can be regulated by Rac and then activate downstream molecule JNK, which in turns activates transcription factor activator protein-1(AP-1). In this study, we found that CTGF could induce collagen expression, and overexpression of wild-type MLK3 also enhanced collagen expression. Overexpressed dominant negative of MLK3 (MLK3 DN) and K252a (a MLK3 inhibtor) concentration-dependently inhibited CTGF-induced collagen expression. CTGF also induced phosphorylation of MLK3 at Thr277/Ser281. Pretreatment of SP600125 (a JNK inhibtor) or transfection with JNK1/2 DN decreased CTGF-induced collagen expression in WI38 fibroblasts. CTGF also induced JNK phosphorylation in time-dependent manner. We also found that curcumin (an AP-1 inhibtor) reduced CTGF-induced collagen expression in a concentration-dependent manner. CTGF induced increase in c-Jun phosphorylation and AP-1-luciferase activity and also increased binding of AP-1 to collagen promoter region. In addition, CTGF induced increases in Rac1 activity, and RacN17 DN inhibit CTGF-induced collagen expression, MLK3 phosphorylation and JNK phosphorylation. CTGF-mediated AP-1 activation was inhibited by RacN17 DN、MLK3 DN and JNK1/2 DN. Taken together, these results suggest that the Rac1/MLK3-dependent JNK/AP-1 signaling pathway plays an important roles in CTGF-induced collagen expression in WI38 fibroblasts.
35
Yang, Hui Lin, and 楊慧霖. "Mechanism of TGF-β1 on the expression of CTGF and type I collagen in hepatic stellate cells." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/74315930419119430793.
Full textAbstract:
碩士長庚大學
中醫學系天然藥物
101
Liver fibrosis is a significant health issue worldwide and continues to increase in prevalence in Taiwan. The main character of liver fibrosis is excessive production of extracellular matrixes and pro-inflammatory factors. Activated hepatic stellate cells (aHSCs) produce high concentrations of transforming growth factor-β1 (TGF-β1), connective tissue growth factor (CTGF), and type I collagen which are closely related to the pathogenesis of liver fibrosis. However, the effects and action mechanisms of TGF-β1 on CTGF and type I collagen expression remain controversial in HSC. Also, the mechanism of CTGF on collagen expression is still not confirmed. In this study, we demonstrated that TGF-β1 significantly induced the protein and mRNA expression of CTGF and type I collagen in concentration- and time-dependent manners in LX-2 cells, a human HSC cell line. Furthermore, we demonstrated that signaling through TGF-β type I receptor was required for TGF-β1-induced CTGF and type I collagen production. Additional experiments were performed to investigate the role of CTGF in type I collagen production. First, CTGF siRNA abrogated TGF-β1-induced CTGF protein expression, but partially inhibited TGF-β1-induced type I collagen protein expression. Second, recombinant CTGF induced expression of type I collagen in HSCs. Multiple observations made in the study suggested that TGF-β1 induced type I collagen expression through a TGF-β type I receptor-mediated Smad2/3 and Akt signaling pathways. Then, activation of Smad2/3 was responsible for TGF-β1-induced CTGF synthesis. Interestingly, by depleting endogenous CTGF and adding recombinant CTGF show that TGF-β1-induced CTGF production has a positive feedback action on type I collagen expression through Akt signaling pathway. In conclusion, our study can contribute to the pro-fibrotic TGF-β signaling and suggest that this pathway may be beneficial for the treatment of liver fibrosis.
36
Lee, Hyejin (Rosa). "Critical role of membrane-type 1 matrix metalloproteinase in collagen phagocytosis by fibroblasts." 2007. http://link.library.utoronto.ca/eir/EIRdetail.cfm?Resources__ID=452972&T=F.
Full text
37
Tang, Ja-Reng, and 湯家潤. "The Regulation of Type II Collagen Gene Expression by Interleukin-1 in Rabbit Chondrocytes." Thesis, 1997. http://ndltd.ncl.edu.tw/handle/28148486945984848271.
Full textAbstract:
碩士台北醫學院
醫學研究所
85
Progressive and irreversible destruction of the extracellular matrix in articular cartilage is a major feature of arthritis. When the joint is destroyed, the prothesis of artificial joint is indicated. However, the metallic joint prothesis often causes severe ankylosis and some complications such as wear problems. Therefore, a biomaterial, collagen template, manufactured in this laboratory was designed to regenerate the articular cartilage.IL-1 is thought to play a major role in the inflammatory and destructive processes associated with the breakdown of cartilage matrix. The regulation of interleukin-1 on cultured chondrocytes was extensively studied. According to previous studies, the synthesis of cartilage-specific collagen is decreased while the synthesis of type I and III collagen are increased in protein and mRNA levels. In order to understand the mechanism of tissue regeneration by implants of the collagen template, the regulatory meIn this study, the regulation of type II collagen gene expression by IL-1, PGE1 and PGE2 in the chondrocyte was determined. In the same time, the suspension cultured chondrocytes for mimicking in vivo cell model also be established.According this study, the expression of type II collagen gene in human chondrocytes is suppressed by IL-1 alone. And IL-1 with indomethacin induced suppression of type II collagen gene expression by human chondrocytes is partially reversed by exogenous prostaglandins (PGE1, PGE2) in a dose- dependent manner. In cell model study, the monolayer cultured chondrocytes assume a fibroblast-like cuboid morphology and may secrete little cartilage-specific intercellular matrix material (they express type I rather t
38
Taylor, Ian Wesley. "The relative contribution of vitamin D receptor (VDR), collagen type 1, α-1 (COL1A1), tumor necrosis factor receptor 2 (TNFR2), polymorphisms, physical activity and bone mineral-free lean mass to bone parameters in children." Thesis, 2002. http://hdl.handle.net/2429/13993.
Full textAbstract:
Background: This study sought to investigate the relationship of physical activity (PA), dietary calcium and 3 candidate gene (VDR, COL1A1 and TNFR2) genotypes on bone mass in children (n = 327, age 10.33 ± 0.65). The study also sought to investigate the effect of PA and genotype on bone mineral-free lean mass (BMFL). Finally, the relationships between bone mass and BMFL and PA, BMFL and genotype and PA and genotype interactions were investigated. Methods: Anthropometric data (height, sitting height and weight) was determined using standard techniques. Bone mass, and BMFL were assed using total body DXA scan using a Hologic QDR 4500. Dietary calcium, PA and maturity were assessed using previously validated questionnaires. VDR FokI and VDR BsmI genotypes were determined by standard restriction fragment length polymorphism techniques. COL1A1 genotype was determined by a novel TaqMan technique and TNFR2 genotypes and haplotypes were determined by a novel automated sequenceing protocol. Associations between PA or candidate gene genotype and either BMFL or bone mass was first controlled for inter-subject differences in body size and maturity. Results: PA was significantly associated with BMFL in boys (p = 0.038). PA score was associated with a 3-5% difference in proximal femur BMC, femoral neck BMC and femoral neck aBMD but not lumbar spine BMC in boys as well as a 4% difference in femoral neck aBMD in girls. Average dietary calcium intake was not associated with differences in bone mass in children. VDR Bsml and VDR Fokl genotype did not have a relationship to bone mass or BMFL in children. COL1A1 Ss or ss genotype is associated with 4.8% higher femoral neck BMC in boys but not BMFL in either sex. TNFR2 A593G gg genotype was associated with a 3.8% higher BMFL in boys (p =0.038) and a 3.4% higher femoral neck BMC in boys (p = 0.045). Girls with a TNFR2 T598G tg genotype had a 3.3% higher femoral neck BMC (p = 0.029). TNFR2 G593-G598/G593-T598 haplotype was associated with a 10% higher femoral neck BMC in girls. For boys, when the BMFL by PA interaction term was added to the model it explained significantly more (2.5-3.9%, p = 0.004) of the variance in femoral neck BMC, femoral neck aBMD and lumbar spine aBMD than the main effect for PA alone. When the BMFL by VDR Fokl genotype interaction was added to the model the main effect of the VDR Fokl genotype became significant where boys with the FF genotype had a 1.4% greater femoral neck aBMD than boys with the Ff or ff genotype. For girls, significant interactions between TNFR2 haplotype and BMFL changed the model such that girls with the G593-G598/G593-T598 haplotype had a 10-11% greater femoral neck BMC or aBMD than girls with other TNFR2 haplotypes. Girls with the Ss or ss genotype had a 4% greater femoral neck aBMD after a significant interaction between COL1A1 genotype and PA was accounted for. Conclusions: High levels of PA are associated with increased BMFL and bone mass. TNFR2 genotypes are associated with both lean mass and bone mass in a complex fashion suggesting that the TNFR2 genotypes and interactions between BMFL and TNFR2 genotypes affect and moderate a combined lean mass/bone mass effect. COL1A1 Ss and ss genotypes are associated with high bone mass particularly in girls with high PA.
39
Bertrand, Marie-Jeanne. "Validation de modalités d’imagerie innovantes de l’athérosclérose par cathéter intravasculaire bimodal combinant fluorescence (NIRF) et ultrasons (IVUS) couplé à l’injection locale de sondes moléculaires in vivo ciblant ICAM-1 et le collagène." Thèse, 2018. http://hdl.handle.net/1866/22544.
Full text