Relevant bibliographies by topics / Β-NGF

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Academic literature on the topic 'Β-NGF'

Author: Grafiati
Published: 3 December 2022

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Journal articles on the topic "Β-NGF"

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Alam, Nur, I. Made Budiarsa, and Dewi Tureni. "Prediksi Struktur Tiga Dimensi Protein β-NGF (Nerve Growth Factor) Burung Merpati (Columba livia)." JURNAL ILMIAH SAINS 20, no. 2 (September 13, 2020): 106. http://dx.doi.org/10.35799/jis.20.2.2020.28857.

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Protein β-NGF berperan dalam kelangsungan hidup sel neuron dan diferensiasi embrio aves yang diekspresikan oleh gen NGF. Informasi protein β-NGF telah diidentifikasi pada ayam dan masih terbatas dilaporkan pada merpati. Tujuan penelitian adalah memprediksi struktur tiga dimensi protein β-NGF merpati untuk menambah informasi karakter proteinnya. Protein target diperoleh dari server UniProt dengan kode akses B4ZE95. Prediksi struktur tiga dimensi dan karakterisasi protein β-NGF menggunakan server SWISS-MODEL dan program Chimera. Hasil analisis menunjukkan bahwa protein β-NGF merpati dan template memiliki nilai identity sebesar 89,91%, QMEAN 0,51 serta GMQE sebesar 0,44. Struktur tiga dimensi protein B4ZE95 memiliki asam amino hidrofobik (Ile, Leu, Trp, Phe, Val, Ala, Gly, Met, Cys); karboksil (Glu, Ser, Asp); amina (Lys, Thr) dengan 83 ikatan hidrogen.Kata kunci: columba livia, chimera, protein β-NGF, swiss-model Three Dimensional Protein Structure Prediction of β-NGF(Nerve Growth Factor) on Pigeon (Columba livia)ABSTRACTThe β-NGF protein plays a role in the survival of neuron cells and differentiation of avian embryo which is expressed by NGF gene. Information of β -NGF protein was identified in chicken and it is still limited reported in pigeon. The purpose of this study is to predict the three-dimensional structure of pigeon β-NGF protein to add information about its protein character. The target protein is obtained from UniProt server with access code B4ZE95. The prediction of three-dimensional structure and characterization of β-NGF protein were carried out using SWISS-MODEL server and Chimera program. The analysis showed that pigeon β-NGF protein and template had identity of 89,91%, QMEAN 0,51 and GMQE of 0,44. The three-dimensional structure of the B4ZE95 protein has hydrophobic amino acids namely (Ile, Leu, Trp, Phe, Val, Ala, Gly, Met, Cys); carboxyl namely (Glu, Ser, Asp); amine namely (Lys, Thr) with 83 hydrogen bonds.Keywords: columba livia, chimera, protein β-NGF, swiss model
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Zhao, Guang-Hua, Ping Yu, Xiao-Song Hu, and Lei Zhao. "Effect of Zn(II) on the Structure and Biological Activity of Natural β-NGF." Acta Biochimica et Biophysica Sinica 36, no. 2 (February 1, 2004): 99–104. http://dx.doi.org/10.1093/abbs/36.2.99.

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Abstract Only β-NGF, the subunit of the 7S NGF complex, exhibits NGF activity, but the function of the zinc ion in native β-NGF has received little attention. Flameless atomic absorption spectroscopy (FAAS) measurements reveal that native β-NGF contains Zn(II) with a Zn(II)/β-NGF stoichiometry of 1:14.6. The presence of Zn(II) in the native molecule results in significant changes of the secondary structure and local tertiary structure around Trp(s) with respect to those of apo β-NGF, as suggested by spectra of fluorescence and circular dichrosim. Stopped-flow studies show that there are at least two steps during the interaction of Zn(II) with the apo form. In comparison with its apo form, the native β-NGF shows a higher ability to trigger the proliferation of TF1 cells and mediate the survival of PC12. Thus it is most likely that the structural changes caused by the presence of Zn(II) directly lead to the increase in the biological activity of β-NGF. All results indicate that Zn(II) in native β-NGF plays an important role in the structure and the biological activity of the protein.
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Montagnoli, Claudia, Roberto Tiribuzi, Lucia Crispoltoni, Alessandra Pistilli, Anna Maria Stabile, Francesco Manfreda, Giacomo Placella, Mario Rende, and Giuliano G. Cerulli. "β-NGF and β-NGF receptor upregulation in blood and synovial fluid in osteoarthritis." Biological Chemistry 398, no. 9 (August 28, 2017): 1045–54. http://dx.doi.org/10.1515/hsz-2016-0280.

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Abstract Osteoarthritis (OA) of the knee is the most common form of non-traumatic joint disease. Previous studies have shown the involvement of β-NGF and its receptors TrKA and p75NTR in OA-related pain, but their role in its pathogenesis is still unclear. The aim of our study was to investigate the amount of β-NGF and the expression levels of its receptors on cells isolated from synovial fluid and blood from OA patients who had undergone total knee arthroplasty, in order to check any possible correlation with the disease staging. Our results show a progressive stage-related increase of β-NGF and its receptors both in serum and synovial fluid. Furthermore, with respect to control subjects, OA patients show an increased amount of inflammatory monocytes along with an increased expression of β-NGF, TrKA and p75NTR. In conclusion, our study suggests a stage-related modulation of β-NGF and its receptors in the inflammatory process of OA.
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Stuart, C. C., J. L. Vaughan, C. M. Kershaw-Young, J. Wilkinson, R. Bathgate, and S. P. de Graaf. "Effects of varying doses of β-nerve growth factor on the timing of ovulation, plasma progesterone concentration and corpus luteum size in female alpacas (Vicugna pacos)." Reproduction, Fertility and Development 27, no. 8 (2015): 1181. http://dx.doi.org/10.1071/rd14037.

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Ovulation in camelids is induced by the seminal plasma protein ovulation-inducing factor (OIF), recently identified as β-nerve growth factor (β-NGF). The present study measured the total protein concentration in alpaca seminal plasma using a bicinchoninic acid (BCA) protein quantification assay and found it to be 22.2 ± 2.0 mg mL–1. To measure the effects of varying doses of β-NGF on the incidence and timing of ovulation, corpus luteum (CL) size and plasma progesterone concentration, 24 female alpacas were synchronised and treated with either: (1) 1 mL 0.9% saline (n = 5); (2) 4 µg buserelin (n = 5); (3) 1 mg β-NGF protein (n = 5); (4) 0.1 mg β-NGF (n = 5); or (5) 0.01 mg β-NGF (n = 4). Females were examined by transrectal ultrasonography at 1–2-h intervals between 20 and 45 h after treatment or until ovulation occurred, as well as on Day 8 to observe the size of the CL, at which time blood was collected to measure plasma progesterone concentrations. Ovulation was detected in 0/5, 5/5, 5/5, 3/5 and 0/4 female alpacas treated with saline, buserelin, 1, 0.1 and 0.01 mg β-NGF, respectively. Mean ovulation interval (P = 0.76), CL diameter (P = 0.96) and plasma progesterone concentration (P = 0.96) did not differ between treatments. Mean ovulation interval overall was 26.2 ± 1.0 h. In conclusion, buserelin and 1 mg β-NGF are equally effective at inducing ovulation in female alpacas, but at doses ≤0.1 mg, β-NGF is not a reliable method for the induction of ovulation.
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Goins, William F., Kevin A. Lee, James D. Cavalcoli, Mark E. O’Malley, Steven T. DeKosky, David J. Fink, and Joseph C. Glorioso. "Herpes Simplex Virus Type 1 Vector-Mediated Expression of Nerve Growth Factor Protects Dorsal Root Ganglion Neurons from Peroxide Toxicity." Journal of Virology 73, no. 1 (January 1, 1999): 519–32. http://dx.doi.org/10.1128/jvi.73.1.519-532.1999.

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ABSTRACT Nerve growth factor β subunit (β-NGF) transgene delivery and expression by herpes simplex virus type 1 (HSV-1) vectors was examined in a cell culture model of neuroprotection from hydrogen peroxide toxicity. Replication-competent (tk− K mutant background) and replication-defective (ICP4−;tk− S mutant background) vectors were engineered to contain the murine β-NGF cDNA under transcriptional control of either the human cytomegalovirus immediate-early gene promoter (HCMV IEp) (e.g., KHN and SHN) or the latency-active promoter 2 (LAP2) (e.g., KLN and SLN) within the viral thymidine kinase (tk) locus. Infection of rat B103 and mouse N2A neuronal cell lines, 9L rat glioma cells, and Vero cells with the KHN or SHN vectors resulted in the production of β-NGF-specific transcripts and β-NGF protein reaching a maximum at 3 days postinfection (p.i.). NGF protein was released into the culture media in amounts ranging from 10.83 to 352.86 ng/ml, with the highest levels being achieved in B103 cells, and was capable of inducing neurite sprouting of PC-12 cells. The same vectors produced high levels of NGF in primary dorsal root ganglion (DRG) cultures at 3 days. In contrast to HCMV IEp-mediated expression, the LAP2-NGF vectors showed robust expression in primary DRG neurons at 14 days. The neuroprotective effect of vector produced NGF was assessed by its ability to inhibit hydrogen peroxide-induced neuron toxicity in primary DRG cultures. Consistent with the kinetics of vector-mediated NGF expression, HCMV-NGF vectors were effective in abrogating the toxic effects of peroxide at 3 but not 14 days p.i. whereas LAP2-NGF vector transduction inhibited apoptosis in DRG neurons at 14 days p.i. but was ineffective at 3 days p.i. Similar kinetics of NGF expression were observed with the KHN and KLN vectors in latently infected mouse trigeminal ganglia, where high levels of β-NGF protein expression were detected at 4 wks p.i. only from the LAP2; HCMV-NGF-driven expression peaked at 3 days but could not be detected during HSV latency at 4 weeks. Together, these results indicate that (i) NGF vector-infected cells produce and secrete mature, biologically active β-NGF; (ii) vector-synthesized NGF was capable of blocking peroxide-induced apoptosis in primary DRG cultures; and (iii) the HCMV-IEp functioned to produce high levels of NGF for several days; but (iv) only the native LAP2 was capable of long-term expression of a therapeutic gene product in latently infected neurons in vivo.
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Dünker, Nicole, Norbert Schuster, and Kerstin Krieglstein. "TGF-β modulates programmed cell death in the retina of the developing chick embryo." Development 128, no. 11 (June 1, 2001): 1933–42. http://dx.doi.org/10.1242/dev.128.11.1933.

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Programmed cell death (PCD) is a key phenomenon in the regulation of cell number in multicellular organisms. We have shown that reduction of endogenous transforming growth factor β (TGF-β) prevents apoptotic PCD of neurons in the developing peripheral and central nervous system, suggesting that TGF-β is an important mediator of ontogenetic neuron death. Previous studies suggested that there are other pro-apoptotic molecules, nerve growth factor (NGF) and brain-derived neurotrophic factor, that induce cell death in the nervous system. In the developing chick retina, NGF induces PCD by activation of the p75 receptor. We have studied the role of TGF-β and its putative interdependence with NGF-mediated PCD in the chick retina. We found that TGF-β is present in the developing chick retina during the period of PCD and is essentially required to regulate PCD of retinal cells. TGF-β2, TGF-β3 and the ligand-binding TGF-β receptor can be detected immunocytochemically in the central retina, a region where apoptosis is most prominent during the early period of PCD. Application of a TGF-β-neutralizing antibody to chick embryos in ovo resulted in a decrease in the number of TUNEL-positive cells and a reduction of free nucleosome levels. In terms of magnitude, reduction of PCD caused by the neutralization of endogenous TGF-β was equivalent to that seen after anti-NGF application. Neutralization of both factors did not result in a further decrease in apoptosis, indicating that NGF and TGF-β may act on the same cell population. Furthermore, neutralization of TGF-β did not affect the expression of NGF or the p75-receptor. Our results suggest that TGF-β and NGF are both required to regulate cell death in the chick retina in vivo.
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Wang, Fei, Kun Yuan, Xiaogang Zhou, Dawei Xu, Yuyu Sun, Feihu Chen, and Peiji Wang. "Nerve Growth Factors Promotes Osteogenic Differentiation Through TGF-β and BMP-9 Signaling Pathways in Bone Mesenchymal Stem Cells." Journal of Biomaterials and Tissue Engineering 10, no. 1 (January 1, 2020): 46–52. http://dx.doi.org/10.1166/jbt.2020.2199.

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Bone mesenchymal stem cells (BMSCs) are related to fracture healing. In this paper, we study the effect of Nerve growth factors (NGF) on osteogenic differentiation of BMSCs and related mechanisms. The results indicated that NGF has a dose-dependent promotion effect on osteogenic differentiation of BMSCs, ALP activity, and protein expression of OPN, Osterix, Runx2, COL1A1. Further investigation showed that NGF enhanced the expression of TGF-β and BMP9, and increased phosphorylation of Smad and p38 MAPK. Moreover, block of BMP and TGF-β pathway reduced the promoted effect of NGF on osteogenic differentiation. The data revealed that NGF increased osteogenic differentiation through increased phosphorylation of Smad and MAPK p38 by regulating TGF-β and BMP pathway in BMSCs. Thus, NGF may be used in bone growth and fracture healing by improving osteogenic differentiation of BMSCs.
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Koga, Takeru, Takaiku Sakamoto, Eiji Sakuradani, and Akihiro Tai. "Neurite Outgrowth-Promoting Activity of Compounds in PC12 Cells from Sunflower Seeds." Molecules 25, no. 20 (October 16, 2020): 4748. http://dx.doi.org/10.3390/molecules25204748.

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In the current super-aging society, the establishment of methods for prevention and treatment of Alzheimer’s disease (AD) is an urgent task. One of the causes of AD is thought to be a decrease in the revel of nerve growth factor (NGF) in the brain. Compounds showing NGF-mimicking activity and NGF-enhancing activity have been examined as possible agents for improving symptoms. In the present study, sunflower seed extract was found to have neurite outgrowth-promoting activity, which is an NGF-enhancing activity, in PC12 cells. To investigate neurite outgrowth-promoting compounds from sunflower seed extract, bioassay-guided purification was carried out. The purified active fraction was obtained by liquid-liquid partition followed by some column chromatographies. Proton nuclear magnetic resonance and gas chromatography-mass spectrometry analyses of the purified active fraction indicated that the fraction was a mixture of β-sitosterol, stigmasterol and campesterol, with β-sitosterol being the main component. Neurite outgrowth-promoting activities of β-sitosterol, stigmasterol, campesterol and cholesterol were evaluated in PC12 cells. β-Sitosterol and stigmasterol showed the strongest activity of the four sterol compounds (β-sitosterol ≈ stigmasterol > campesterol > cholesterol), and cholesterol did not show any activity. The results indicated that β-sitosterol was the major component responsible for the neurite outgrowth-promoting activity of sunflower seeds. Results of immunostaining also showed that promotion by β-sitosterol of neurite formation induced by NGF was accompanied by neurofilament expression. β-Sitosterol, which showed NGF-enhancing activity, might be a candidate ingredient in food for prevention of AD.
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Selvaraju, Vaithinathan, Jeganathan R. Babu, and Thangiah Geetha. "Salivary Neurotrophins Brain-Derived Neurotrophic Factor and Nerve Growth Factor Associated with Childhood Obesity: A Multiplex Magnetic Luminescence Analysis." Diagnostics 12, no. 5 (May 3, 2022): 1130. http://dx.doi.org/10.3390/diagnostics12051130.

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Obesity is linked with higher inflammatory markers and is characterized by chronic low-grade inflammation. Neurotrophins brain-derived neurotrophic factor (BDNF) and β-nerve growth factor (β-NGF), in addition to their neuronal functions, act on several immune cells and have been recently designated as metabokines due to their regulatory role in energy homeostasis and food intake. The current study evaluates the salivary BDNF and β-NGF and their association with anthropometric measurement, blood pressure, and salivary insulin in children. Anthropometric measurements and saliva samples were obtained from 76 children, aged 6–10 years. Multiplex analysis was carried out for the salivary analysis of BDNF, NGF, and insulin by human magnetic Luminex performance assay. Statistical analysis was performed to analyze the best fit diagnostic value for biomarkers and the relationship of the neurotrophic levels of BDNF and NGF with obesity measures and blood pressure. Salivary BDNF and β-NGF showed a significantly higher concentration in obese children than normal-weight children. Both neurotrophins are positively associated with obesity anthropometric measures, blood pressure, and salivary insulin. Multinominal regression analysis reported a significant association between salivary BDNF, β-NGF, insulin, and systolic pressure adjusted for age, gender, income, and maternal education. The salivary concentration of BDNF and NGF was higher in obese children, and it is positively associated with anthropometric measures, suggesting that neurotrophins can be used as a non-invasive predictor of obesity-related complications in children.
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Masdeu, M., R. M. Garcia-Garcia, R. Cardinali, P. Millan, M. Arias Alvarez, C. Castellini, P. L. Lorenzo, and P. G. Rebollar. "271 INDUCTION OF OVULATION IN RABBIT DOES USING PURIFIED NERVE GROWTH FACTOR AND CAMEL SEMINAL PLASMA." Reproduction, Fertility and Development 27, no. 1 (2015): 224. http://dx.doi.org/10.1071/rdv27n1ab271.

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The presence of an ovulation-inducing factor (OIF) in the seminal plasma (SP) of several species with spontaneous and induced ovulation, including the rabbit, has been documented. Recent studies have demonstrated that the OIF in the SP of camels (SPCAM) is a nerve growth factor (β-NGF). The aim of this study was to determine if purified β-NGF from mouse submandibular glands or SPCAM could provoke ovulation induction in the rabbit doe. A total of 35 females were synchronized with 25 IU of equine chorionic gonadotropin (Serigan, Laboratorios Ovejero, Spain) and allocated into 4 groups. Forty-eight hours later (Day 0), does were given a single dose (IM) of 1 mL of saline solution (SS; n = 8); 1 mL of gonadorelin (GnRH; Inducel, Laboratorios Ovejero, Spain; n = 9); 24 µg of β-NGF (2.5S-NGF; Promega, USA; n = 10); or 1 mL of centrifuged raw camel SP (SPCAM; 127 pg mL–1 NGF; n = 8). After treatment, an empty catheter was introduced through the vagina to simulate the nervous/mechanical stimulus of coitus (4 animals per group). Plasma LH concentrations were determined in blood samples taken 30 min before treatment and at 0, 30, 60, 90, and 120 min after injection. Progesterone concentrations were assessed at 0 and 120 min and every 2 days until Day 6 after treatment. Concentrations of β-NGF in camel SP and hormone determinations were made by enzyme immunoassay. Ovulation rate (OR) was determined after euthanasia on Day 7. Statistical analyses using CATMOD and MIXED procedures of the SAS program to compare OR data and hormone concentrations, respectively, were performed. Ovulation occurred in 100% of GnRH (9/9), 33% (3/10) of NGF, 25% (2/8) of SS, and 0% (0/8) of SPCAM groups. Both NGF and SS ovulated females had significantly lower LH concentration than GnRH group throughout all preovulatory surge (P < 0.001). When does were not stimulated with catheter introduction, only those from the GnRH (5/5) and NGF (1/6) groups ovulated. Total number of corpora lutea in ovulated does was similar (15.9 ± 1.9, 17.0 ± 4.2, and 14.3 ± 3.1 CL in GnRH, SS, and NGF groups, respectively). Plasma P4 concentrations were normally increased from Day 2 to 6 in ovulated rabbits of all groups, but were lower at 120 min (P < 0.001) for the NGF and SS does, reaching similar levels than GnRH does at 6 days post-treatment. In the present study, β-NGF from mouse submandibular glands, but not from raw camel SP, induced ovulation in rabbit females, independently of nervous stimulus. Nonetheless, the possible low dose of β-NGF used and the origin could have been responsible for the lack of a more acute effect.We acknowledge CM, FSE, and AGL2011-23822 for funding.
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Dissertations / Theses on the topic "Β-NGF"

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Paul, Alan Burnett. "β-NGF and its low-affinity receptor (p75LNGFR) in benign prostatic hyperplasia and adenocarcinoma of the prostate." Thesis, University of Edinburgh, 1999. http://hdl.handle.net/1842/29936.

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β-NGF was measured in human benign prostatic hyperplastic (BPH), adenocarcinomatous and normal tissues using an enzyme-linked immunosorbent assay. Concentrations were 1992pg/g wet weight in BPH tissue (SD = 684pg/g), 3100pg/g in adenocarcinomatous tissue (SD = 1503pg/g), and 2690pg/g in normal tissue. mRNA transcripts for β-NGF were demonstrated in prostate tissues by reverse transcription-polymerase chain reaction showing that the β-NGF measured in prostate tissue was endogenously produced. Western blotting allowed the demonstration that immunoreactive β-NGF in the prostate represented dimeric β-NGF and not behaviour β-NGF-like proteins which have been described elsewhere. Immunohistochemistry for β-NGF localised the hormone to the prostate epithelium in BPH, cancer and normal tissue. This epithelial localisation was confirmed by video-assisted tissue morphometric studies. Thereby it was shown that specimen β-NGF concentrations correlated well and statistically significantly with specimen prostatic glandular content. Morphometric studies also allowed the expression of β-NGF concentrations in terms of each specimen's contained, β-NGF secreting, glandular tissue. Thereby it was demonstrated that BPH glandular tissue produced greater concentrations of β-NGF (1597pg/100mg glandular tissue, SD = 788pg/100mg) than did malignant glandular tissue (1058pg/100mg glandular tissue, SD = 559pg/100mg), in spite of the higher concentrations of β-NGF found grossly in adenocarcinomatous tissue. β-NGF concentrations did not correlate with differential of adenocarcinomas or with the degree of neurodocrine differentiation therein. The thesis suggests that human prostatic β-NGF has a role similar to that described in other tissues. That is the maintenance and stimulation of adrenergic nerves. This may be relevant to the widespread use of sympatholytic drugs in the treatment of BPH.
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Ainani, Hassan. "Contrôle central de la reproduction chez le dromadaire : effet des saisons et du facteur inducteur d’ovulation (β-NGF) sur les neurones à kisspeptine et à RFRP-3." Thesis, Strasbourg, 2021. http://www.theses.fr/2021STRAJ110.

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Le dromadaire (Camelus dromedarius), un mammifère hautement adapté au désert, est sexuellement actif durant les jours courts. Cette période coïncide avec la disponibilité de la nourriture et des conditions climatiques favorables à la survie de la progéniture. A cette période, les femelles présentent une ovulation provoquée par le β-NGF présent dans le plasma séminal des mâles. A l’heure actuelle, les mécanismes impliqués dans le contrôle central de la reproduction et de l’induction de l’ovulation restent inconnus. Durant cette thèse nous avons montré que les neurones à Kp et RFRP-3, deux RFamides impliqués dans le contrôle de la reproduction saisonnière, sont présent dans l’hypothalamus du dromadaire. Ces deux neurones présentent des variations saisonnières opposés suggérant un rôle de ces RFamides dans la régulation saisonnière de la reproduction du dromadaire avec probablement des effets physiologiques différents. Par ailleurs, nous avons montré que l’effet ovulatoire du β-NGF est induit en activant majoritairement les neurones qui sont directement impliqués dans la reproduction, à savoir la Kp, le GnRH et le RFRP-3
The dromedary (Camelus dromedarius), a highly adapted mammal to the desert, is sexually active during short days. This period coincides with food availability and favourable climatic conditions to the survival of the offspring. At this time, females exhibit ovulation induced by neuronal growth factor beta (β-NGF) present in seminal plasma of males. Currently, the mechanisms involved in the central control of breeding and the induction of ovulation remain unknown. During this thesis we showed that Kp and RFRP-3 neurons, two RFamides involved in the control of seasonal breeding, are present in the hypothalamus of dromedaries. These two neurons present opposite seasonal variations suggesting a role of these RFamides in the seasonal regulation of dromedary reproduction with probably different physiological effects. Furthermore, we have shown that the ovulatory effect of β-NGF is induced by activating mainly the neurons that are directly involved in reproduction, namely Kp, GnRH and RFRP-3
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Spittau, Gabriele Verfasser], Bertram [Akademischer Betreuer] [Brenig, Christoph [Akademischer Betreuer] Knorr, and Kerstin [Akademischer Betreuer] Krieglstein. "Untersuchungen zur Rolle von Klf10 und Klf11 als Mediatoren von NGF- und TGF-β-vermittelten Effekten in Zellen neuraler Herkunft / Gabriele Spittau. Gutachter: Bertram Brenig ; Christoph Knorr ; Kerstin Krieglstein. Betreuer: Bertram Brenig." Göttingen : Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2012. http://d-nb.info/1043765980/34.

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Annerén, Cecilia. "The Tyrosine Kinase GTK : Signal Transduction and Biological Function." Doctoral thesis, Uppsala University, Department of Medical Cell Biology, 2001. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-1384.

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Protein tyrosine kinases play an important role in the regulation of various cellular processes such as

growth, differentiation and survival. GTK, a novel SRC-like cytoplasmic tyrosine kinase, was recently cloned from a mouse insulinoma cell line and the present work was conducted in order to find a biological function of GTK in insulin producing and neuronal cells. It was observed that kinase active GTK-mutants, expressed in RINm5F cells, transferred to the cell nucleus and increased the levels of the cell cycle regulatory protein p27KIP1, reduced cell growth and stimulated glucagon mRNA expression. Furthermore, wild type GTK induces neurite outgrowth in the rat adrenal pheochromocytoma PC12 cell line, through activation of the RAP1-pathway, suggesting a role of GTK for cell differentiation. Studies using transgenic mice, expressing GTK under the control of the rat insulin 1 promoter, demonstrated a dual role of GTK for β-cell growth: Whereas GTK increases the β-cell mass and causes enhanced β-cell proliferation in response to partial pancreatectomy it also induced β-cell death in response to proinflammatory cytokines and impaired the glucose tolerance in mice treated with the β-cell toxin streptozotocin suggesting a possible role of GTK for β-cell destruction in Type 1 diabetes. We have also observed that GTK-transgenic islets and GTK-expressing RINm5F cells exhibit a reduced insulininduced activation of the insulin receptor substrate (IRS-1 and IRS-2)-pathways, partly due to an increased basal activity of these. GTK was found to associate with and phosphorylate the SH2 domain adapter protein SHB, which could explain many of the GTK-dependent effects both in vitro and in vivo. In summary, the present work suggests that the novel tyrosine kinase GTK is involved in various signal transduction pathways, regulating different cellular responses, such as proliferation, differentiation and survival.

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Chaaya, Nancy. "Anticorps catalytiques et répertoires immuns murins : analyse génétique, biochimique et bio-informatique." Thesis, Compiègne, 2019. http://www.theses.fr/2019COMP2495.

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A la fin des années 80, des anticorps catalytiques ont été découverts dans le sérum de patients, en particulier de patients atteints de maladies auto-immunes. Certains anticorps catalytiques ont un effet bénéfique sur la santé, tandis que d'autres sont délétères. Afin de comprendre le lien existant entre anticorps catalytiques et pathologies auto-immunes, des travaux antérieurs ont mené à la synthèse de quatre banques de fragments d’anticorps (scFv) exposés en surface de phages, représentant différents fonds génétiques et états immunologiques. Les scFv, constitues des régions variables des chaines lourdes (H) et légères (L) des anticorps, sont codes par différents segments de gènes d'immunoglobuline : V-D- J pour la chaine lourde, V et J pour la chaine légère. Dans l'objectif de récolter des informations sur l’immunogénétique des anticorps catalytiques, la distribution des sous-groupes de gènes au sein de chaque répertoire a été étudiée, en se basant sur l’étude de plus de 300 000 séquences. L'analyse des données NGS a montré une expression différentielle des sous-groupes de gènes selon la banque d’origine, suggérant que le fond génétique et / ou l'état immunologique influencent l'expression du sous-groupe de gènes d'immunoglobuline. La présence d'anticorps potentiellement catalytiques à activité β-lactamase a ensuite été étudiée dans les quatre banques par une approche in silico de modélisation tridimensionnelle. Les résultats suggèrent que certaines banques expriment potentiellement plus d'anticorps catalytiques que d'autres. Enfin, dans le but de valider cette approche in silico, une approche in vitro a été initiée. Cinq scFv exposés à la surface des phages ont été sélectionnés lors d'un travail précèdent par un processus itératif sur la base de leur activité catalytique. Chacun possède une structure primaire et tertiaire unique. L’un d’entre eux, le scFv P90C2, a été cloné et exprimé dans des bactéries E. coli BL21 (DE3) sous forme de corps d'inclusion, puis solubilise et enfin renaturé. Bien que le scFv P90C2 soluble conserve son activité de reconnaissance, son pouvoir catalytique est complètement perdu. L’influence de différents paramètres sur la fonctionnalité du scFv a été évaluée : (i) optimisation des conditions du protocole de renaturation, (ii) choix des codons à l’origine de la séquence peptidique du scFv, et enfin (iii) influence de la protéine de fusion pIII
In the late 80s, catalytic antibodies have been discovered in the serum of patients, especially patients with auto-immune diseases. Some of the catalytic antibodies appear to have a beneficial effect on health while others are deleterious. In order to understand the link between catalytic antibodies and immune system pathologies, previous work leaded to 4 single chain Fragment variable (scFv) libraries exposed on phage surface, representing different genetic backgrounds and immunological states. The scFvs, composed with the variable regions of the heavy (H) and light (L) chains, are encoded by immunoglobulin gene subgroups V(H), D(H), J(H), V(L) and J(L). With the objective to decipher the potential origin of catalytic antibodies, a statistical representation of each subgroup within each repertoire has been done, based on more than 300 000 sequences. The NGS data analysis showed a variable expression of some gene subgroups (comprising “rare” ones) between the 4 libraries showing that the genetic background and/or the immunological state influence immunoglobulin gene subgroup expression. Then, we investigated the presence of antibodies with potent active sites in the libraries by molecular modelling. Libraries express more putative catalytic antibodies than others depending on the genetic background and the immunological state profile. Finally, in the objective to validate this in silico approach, an in vitro approach was considered. 5 scFvs exposed on phage surface have thus been selected during a previous work by iterative process on the basis of their catalytic activity: β-lactamase like activity. Each of them displays a unique primary and tertiary structure. The scFvs exposed on the phage surface must be catalytically active while expressed in soluble form too. One of the selected scFvs, P90C2, was optimized and expressed in E. coli BL21 (DE3) bacteria in the form of inclusion bodies and then solubilized and refolded. Although soluble P90C2 fully retained its binding activity, its catalytic potency was completely lost. Further experiments aimed to i) optimize refolding protocol, ii) study the impact of scFv codon-optimization, and iii) show the influence of the pIII fusion protein on the scFv catalytic activity
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Spittau, Gabriele. "Untersuchungen zur Rolle von Klf10 und Klf11 als Mediatoren von NGF- und TGF-β-vermittelten Effekten in Zellen neuraler Herkunft." Doctoral thesis, 2011. http://hdl.handle.net/11858/00-1735-0000-000D-EF49-C.

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Wang, Cheng-Ting, and 王澄霆. "NGF encapsulated into lactoferrin grafted liposomes for transporting across the blood-brain barrier and counteracting the degeneration of SK-N-MC cells induced apoptosis by β-amyloid peptide." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/99824918269394572452.

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碩士
國立中正大學
化學工程研究所
100
In order to improve the low permeability of nerve growth factor (NGF) in the brain. Here, use liposomes as drug carriers which were mixed with saturated phospholipids DPPC and cholesterol. The liposomes encapsulate NGF and surface modified with lactoferrin to increase cellular uptake. Investigating the NGF permeability of the in vitro blood brain barriers (BBB) model was established by human brain microvascular endothelial cells (HBMECs) and human astrocytes (HAs) on the transwell, and the protective effect of NGF against the in vitro Alzheimer’s disease (AD) neurodegenerative model was established by SK-N-MC neuroblastoma cell line induced apoptosis byAβ1-42 fibrils. The results indicated that an increase in molar percentage of cholesterol enhanced the average diameter and stability of liposomes, and decreased the entrapment efficiency and release rate of NGF. Moreover, an increase in grafted Lf enhanced the positive charge of Lf modified liposmoes, slightly increased the zeta potential and average diameter, the average diameter increased approximately 12 nm compared to unmodified liposomes and the loading efficiency of Lf was at least 87%. In this study, applied the Lf modified liposomes with 50 mol% cholesterol to encapsulate NGF (defined as Lf/NGF-liposomes) across in vitro BBB model, reduced the transendothelia electrical resistance (TEER) from 204 Ωcm2 to 137 Ωcm2. In addition, there was a three-fold enhancement of permeability with Lf/NGF-liposomes versus NGF encapsulated by unmodified liposomes, and over 5.7-fold increase over free NGF treatments. The results of NGF encapsulated into liposomes counteracted the degeneration of SK-N-MC cells induced apoptosis by fibrillar Aβ1-42 revealed that the cell viability of Lf/NGF-liposomes treatments was higher than the viability of free NGF treatments, and an increase in the concentration of Lf enhanced the viability significantly. Finally, HBMECs and SK-N-MC cells were incubated with fluorescent liposomes, and the fluorescent images indicated that Lf could enhance cellular uptake. These evidences suggested that NGF encapsulated into lactoferrin grafted liposomes can enhance the permeability against BBB and attenuate β-amyloid induced apoptosis in SK-N-MC cells. Therefore, Lf/NGF-liposomes can be of potential in Alzheimer’s disease therapy for clinical application.
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Lin, Chun Ching, and 林敬鈞. "NGF and Curcumin Encapsulated into Wheat Germ Agglutinin Grafted Cardiolipin Liposomes for Transporting across the Blood-brain Barrier and Counteracting the Degeneration of SK-N-MC Cells Induced Apoptosis by β-amyloid Peptide." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/70540685779515642775.

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碩士
國立中正大學
化學工程研究所
101
In order to improve the hydrophilic and poor bioavailability of curcumin and the low permeability of nerve growth factor (NGF) in the brain, liposomes were used to be drug carriers to encapsulate curcumin and NGF. The liposomes content with cardiolipin were provided with high affinity for β-amyloid (Aβ). The surface of liposomes was modified with wheat germ agglutinin (WGA) to increase cellular uptake. Investigating the curcumin NGF permeability of the in vitro blood brain barriers (BBB) model was established by human brain microvascular endothelial cells (HBMECs), human pericytes (HPs) and human astrocytes (HAs) on the transwell, and the protective effect of curcumin and NGF against the in vitro Alzheimer’s disease (AD) neurodegenerative model was established by SK-N-MC neuroblastoma cell line induced apoptosis by Aβ1-42 fibrils. The results indicated that an increase in molar percentage of cardiolipin enhanced the average diameter and zeta potential. The average diameter increased approximately 6 nm compared to unmodified liposomes. HBMECs were incubated with fluorescent liposomes, and the fluorescent images indicated that WGA could enhance cellular uptake. SK-N-MC cells were incubated with fluorescent liposomes and fibrillar Aβ1-42, and the fluorescent images indicated that the liposomes content with cardiolipin could bind on the fibrillar Aβ1-42. These evidences suggested that cuecumin and NGF encapsulated into WGA grafted cardiolipin liposomes can enhance the permeability against BBB and attenuate β-amyloid induced apoptosis in SK-N-MC cells. Therefore, WGA/curcumin-NGF-cardiolipin liposomes can be a potential drug in Alzheimer’s disease therapy for clinical application.
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Book chapters on the topic "Β-NGF"

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Houlgatte, R., D. Wion, P. Barrand, E. Dicou, and P. Brachet. "Serum Influences β-NGF Gene Expression in Mouse L Cells." In Proceedings in Life Sciences, 40–42. Berlin, Heidelberg: Springer Berlin Heidelberg, 1986. http://dx.doi.org/10.1007/978-3-642-70690-5_8.

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Ebendal, Ted, Finn Hallböök, Carlos Ibañez, Håkan Persson, Lars Olson, and Lena Lärkfors. "Activity and Immunological Properties of Recombinant Nerve Growth Factor (β-NGF)." In Brain Repair, 57–71. London: Macmillan Education UK, 1990. http://dx.doi.org/10.1007/978-1-349-11358-3_5.

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Čarman-Kržan, Marija, Damijana M. Juric, and Vesna Pahor. "Interleukin-1 β Receptor Mediated NGF Synthesis and Secretion from Rat Cortical Astrocytes." In Neurochemistry, 501–6. Boston, MA: Springer US, 1997. http://dx.doi.org/10.1007/978-1-4615-5405-9_84.

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Conference papers on the topic "Β-NGF"

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Shenoy, B. Satish, Rammohan S. Pai B., Raghuvir Pai B., and Shrikanth Rao D. "Effect of Turbulence and Offset Loading on the Performance of a Single Pad Externally Adjustable Fluid Film Bearing." In ASME 2012 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/imece2012-85760.

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Paper deals with the effect of turbulence on steady state performance characteristics of an eccentrically loaded 120° single pad externally adjustable fluid film bearing. The bearing has an aspect ratio of one and operates over a wide range of eccentricity ratios and adjustments. Two load-offset positions (β/χ) of 0.45 and 0.55 are considered in the present analysis. Reynolds equation incorporated with the Linearized turbulence model of Ng and Pan is solved numerically using finite difference method. A comparative study predicts that, load capacity of a bearing operating with β/χ = 0.55 and Re = 16000 is superior for negative radial and tilt adjustment configuration of the pad.
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Van, Adriana Le, Nazia Rahman, Nelson Dozier, Patrick Mc Gann, James Regeimbal, Andrea Mccoy, Olusegun Soge, Eric Garges, and Ann Jerse. "P645 Peruvian gonococcal strains reveal novel NG-MAST types and false-positive β-lactamase isolates withblatemgene mutations." In Abstracts for the STI & HIV World Congress (Joint Meeting of the 23rd ISSTDR and 20th IUSTI), July 14–17, 2019, Vancouver, Canada. BMJ Publishing Group Ltd, 2019. http://dx.doi.org/10.1136/sextrans-2019-sti.713.

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SILVEIRA, ANA CAROLINA ATAIDE, JEFFERSON JOE MOREIRA ALVES, LUAN SOUZA DE PAULA GOMES, MATHEUS HENRIQUE TEIXEIRA, and DEMERSON ARRUDA SANGLARD. "VALIDAÇÃO DE UM PROTOCOLO ÁGIL E EFICAZ PARA EXTRAÇÃO DE DNA DE FOLHAS MADURAS DE ACESSOS DE MILHOS CRIOULOS." In III Congresso Brasileiro de Ciências Biologicas. Revista Multidisciplinar de Educação e Meio Ambiente, 2022. http://dx.doi.org/10.51189/iii-conbracib/7280.

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Introdução: A extração de DNA é um dos principais procedimentos para a utilização de técnicas moleculares. Possui enorme importância nos protocolos de amplificação via Reação em Cadeia da Polimerase (Polymerase Chain Reaction - PCR). Esta, por sua vez, permite estimar a dissimilaridade genética entre acessos de uma população, selecionar genes específicos, realizar estudos de alelismo, construir mapas genéticos, obter clonagens posicionais, dentre muitos outros procedimentos úteis ao melhoramento genético.Objetivos: Validar um protocolo de extração de DNA com rapidez e elevada pureza, a partir de folhas maduras de 44 acessos de milhos crioulos prospectados no Norte de Minas Gerais. (Zea mays L.).Material e métodos: Testou-se procedimentos modificados baseados no protocolo de base CTAB (Brometo de Cetil Trimetilamonio ou Cetyl trimethylammonium bromid). Nesse protocolo foram utilizadas diferentes concentrações de β-mercaptoetanol no tampão de extração (0,0; 0,2; 10; 15; 25; e 50 uL de β-mercaptoetanol/mL), considerando o seguinte tampão de extração: Tris-HCl 100 mM em pH 8; EDTA 20 mM; NaCl 1,4 mM; CTAB 2% e; PVP 1%). Os procedimentos foram conduzidos no Laboratório de Biotecnologia da Universidade Federal de Minas Gerais (campus Montes Claros), fomentados pelo Banco do Nordeste (Fundo de Desenvolvimento Econômico, Científico, Tecnológico e de Inovação - FUNDECI).Resultados: O protocolo foi eficiente no isolamento de DNA livre de polissacarídeos e polifenóis, com rendimento do DNA de alto peso molecular e concentrações acima de 120 ng/uL, utilizando-se valores superiores a 1% de β-mercaptoetanol no tampão de extração. Outras modificações importantes se ativeram aos passos da maceração, substituindo o uso do nitrogênio líquido (trituração das amostras em cadinho e pistilo), por uma ação direta do aparelho disruptor/homogeneizador de amostras biológicas, nos microtubos acrescidos do tampão. Além disso, adicionou-se duas rodadas para desproteinização (clorofórmio álcool isomílico 24:1), sendo os dois passos de pousios resfriados das amostras realizados apenas em ultrafreezer (-75oC) durante 10 min (cerca de 48 h poupadas).Conclusão: O protocolo de base CTAB para extração de DNA, inicialmente proposto para folhas de plantas leguminosas (largas), também foi eficaz em folhas maduras de acessos de milhos crioulos (gramíneas), levando em conta adaptações que permitiram pureza e celeridade ao processo.
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Ariatabar, B., R. Koch, and H. J. Bauer. "Short Helical Combustor: Concept Study of an Innovative Gas Turbine Combustor." In ASME Turbo Expo 2015: Turbine Technical Conference and Exposition. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/gt2015-42963.

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An innovative design of a gas turbine annular combustor is investigated analytically and numerically. Its principal feature is the helical arrangement of the burners around the turbine shaft. Hence, a shorter combustor with lower aerodynamical losses and cooling air demand might be realized. A generic model of the combustor is developed and analyzed by means of a parametric study. Scaling laws for the geometry of the flame tube and the burners are derived. Thereby, the relevant similarity parameters for fluid flow, combustion and heat transfer are maintained constant. Subsequently, non-reacting and reacting flow regimes of selected design variants are numerically investigated. It is shown that a double annular configuration with a tilting angle of β = 45°, where circumferentially adjacent swirls are co-rotating and radially are counter-rotating, is the superior design in terms of 1. Maintaining the relevant similarity rules 2. Size and location of the recirculation zones and swirl flames 3. Flow pattern at the combustor exit The deflection angle of the NGV as well as the axial length of such a Short Helical Combustor could be reduced by approx. 30%.
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Sugihara, T., J. Takamatsu, T. Kamiya, H. Saito, K. Kimata, and K. Kato. "A SENSITIVE ENZYME-LINKED IMMUNOSORBENT ASSAY(ELISA) FOR SERUM LAMININ." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1643554.

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Laminin, a large glycoprotein, is a major and specific component of basement membrane. There were little or no circulating laminin in normal persons, although some recent reports have showed increased values in various diseases(ex. diabetes mellitus and liver disease) by a radioimmunoassay(RIA) using laminin fragment. The minimum detectable sensitivity of RIA was reported to be 20 ng/ml of serum sample. We describe here a more sensitive immunoassay system, and also the concentrations of laminin in sera from healthy subjects and patients. A sandwich ELISA method for measurement of laminin was established by use of purified antibodies to mouse laminin. The assay system consisted of poly-stylene balls with immobilized antibody F(ab’)2 fragments and the same antibody Fab1 fragments labeled with β-D-galactosidase from E.Coli. The assay was highly sensitive and can detect as small as 0.5 ng/ml of serum laminin.Coefficients of variation in within-run and between-run precision studies for serum laminin were good. Serum laminin levels in healthy subjects of various ages ranged from 1.5 to 3.9 ng/ml(n=60). Fifty eight patient sera (collagen disease(n=18), hepatic disease(n=20), and renal disease (n=20)) were examined. Significant differences between the normal sera and 3 diseases sera were observed as shown belowIt is concluded that circulating laminin apparently exists in normal persons and there are higher laminin level in some diseases which appears to involve basement membrane-rich organ
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Hashimoto, Y., A. Kobayashi, N. Yamazaki, Y. Sugawara, Y. Takada, and A. Takada. "RELATIONSHIP BETWEEN AGE AND t-PA ANTIGEN, PA INHIBITOR ACTIVITY AND PA ACTIVITY." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1643125.

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A positive correlation between age and the occurrence of thrombosis has been suggested. We studied relationship between age and fibrinolytic activities; namely levels of tissue plasminogen activator (t-PA) antigen, activity of t-PA inhibitor (PA inhibitor activity) and activity of t-PA (PA activity). Plasma samples were obtained from 88 apparently healthy volunteers. t-PA antigen was measured by enzyme immunoassays(EIA). Monoclonal and polyclonal anti-t-PA antibodies were employed as the first and the second antibodies for EIA, respectively. Polyclonal t-PA antibody was raised in a rabbit after injection of purified t-PA and was labeled with β-D-galactosidase. Monoclonal anti-t-PA was obtained from IMCO Co., Ltd (Stockholm, Sweden). PA inhibitor activity was measured by inhibition of purified t-PA by diluted plasma. PA activity in the euglobulin fraction of plasma samples was measured by the hydrolysis of S-2251 after the addition of Glu-plasminogen. PA activity was calculated from the standard curve of t-PA. Plasma levels of t-PA antigen increased with increase in age. The leveles of t-PA antigen increased from 4.31 ± 1.55 ng/ml (mean ± SD) at the age range of 10 to 20, to 9.18 ± 2.34 ng/ml at the age range of 50 to 60. Increase in levels of t-PA antigen was quite linear with respect to increase in age. In 30 healthy volunteers, plasma PA inhibitor activity also increased with increase in age. PA activity in plasma of 20 healthy volunteers decreased with age, indicating that free t-PA antigen levels decreased with age. In conclusion, dramatic increase in both t-PA antigen and PA inhbitor activity was shown in persons with increasing age. PA activity decreased with age. Therefore it is suggested that tendency of decreased PA activity with increasing age may be related to high incidence of thrombosis in older persons.
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Del Maschio, A., M. Albors, F. Bucchi, M. Tomasiak, V. Bertele, C. Cerletti, and G. de Gaetano. "HUMAN POLYMORPHONUCLEAR LEUKOCYTE ACTIVATION INDUCED BY PLATELET ACTIVATING FACTOR (PAF)." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1643482.

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Human polymorphonuclear leukocytes (PMNs) loaded with the photoprotein Aequorin, were exposed to PAF in the presence of extracellular Ca2+ (1 mM). PMNs aggregation measured In the “Platelet Ionized Calcium Aggregometer” (P.I.C.A.) was dependent on the concentration of the stimulus. Ca2+ cytoplasmatic increase was monitored in parallel at concentrations of PAF which did not modify cellular integrity (10-7-10-5M). The intracellular Ca2+ flux (up to 19±3 µM) triggered by PAF was also concentration-dependent. In order to establish the role played by this intracellular messenger, we studied some cellular responses possibly related to Ca2+ mobilization: enzymatic release, oxygen radicals production, and arachidonic acid metabolism. PAF induced release of both lysozyme , and β-glucuronldase (15% to 20% of the total enzyme content at the maximal concentration). However PAF (10-712-10“Vl) stimulated the production of only small amounts of oxygen radicals as compared to Phorbol Myristate Acetate (PMA). Leukotriene B4 (LTB4), the main arachidonic acid metabolite in PMNs and the products of its catabolism (20-OH and 20-C00H LTBO were assayed by two different technics (HPLC and RIA) in the same cellular suspensions. PAF (10-4 M)-stimulated PMNs (0.5-2xl07 cells/ml) did not produce any detectable amount of these arachidonic acid metabolites. In contrast, calcium ionophore A 23187 (2 μM)-stimulated PMNs (in the same range of cellular concentration) produce up to 170 ng/ml of LTB4. In conclusion, cytoplasmatic Ca2+ increase in PAF-stimulated PMNs was not accompanied either by oxygen radicals production or by activation of arachidonic acid metabolism catalyzed by 5-1 ipoxygenase.
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Loskutoff, D. J., J. Mimuro, and C. Hekman. "PLASMINOGEN ACTIVATOR INHIBITOR." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1644763.

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Plasminogen activation provides an important source of localized proteolytic activity not only during fibrinolysis, but also during ovulation, cell migration, epithelial cell differentiation, tumor invasion and a variety of other physiological processes. Precise regulation of plasminogen activator (PA) activity thus constitutes a critical feature of many biological processes. This control is achieved in large part through the action of specific PA inhibitors (PAIs). Although 4 distinct PAIs have been detected,1the endothelial cellTderived inhibitor (PAI-1) is the only one that efficiently inhibits both urokinase (Kd=2.3×10−13M; Kassoc =1.6×108 M−1s−1) and single-chaintissue-type PA (tPA; Kd=1.3×lO−15 M Kd=3.9×lO7M−1s−1). It also inhibits trypsin (Kassoc=6.8×106M−1 s−1 ) ancl Plasmin (Kassoc=7.6×l05 M−1 s5 Analysis of the effect of PAI-1 on the rate of plasminogen activation revealed a competitive type of inhibition when urokinase was employed but a linear mixed type of inhibition when single chain tPA was employed. These results suggest that the interaction of PAI-1 with tPA, in contrast to its interaction with urokinase, may involve 2 sites on the tPA molecule.PAI-1 has been purified from medium conditioned by cultured bovine aortic endothelial cells and partially characterized. It is a major biosynthetic product of these cells, accounting for as much as 12% of the total protein released by the cells in 24 h. It has an M of 50,000, an isoelectric point of 4.5-5.0, and is immunologically and biochemically related to the rapidly acting inhibitor present in human platelets and in the plasma of some patients at risk to develop thrombotic problems. Although it is relatively stable to conditions which inactivate most protease inhibitors (acid pH, SDS), it is extremely sensitive to oxidants. The molecular cloning of the PAI-1 gene revealed that the mature human protein is 379 amino acids long, contains an NH2-terminal valine, lacks cysteines and has a methionine at the Pi position of it's reactive center. The conversion of this methionine to methionine sulfoxide may be responsible for the rapid inactivation of PAI-1 by oxidants. Human PAI-1 has extensive (30%) homology with α1-antitrypsin and antithrombin III and is thus a member of the serine proteinase inhibitor (serpin) family; a group of related molecules that control the major protease cascades of the blood. The PAI-1 gene is approximately 12.2 kilobase pairs in length and is organized into nine exons and eight introns.The production of PAI-1 by endothelial cells is stimulated by endotoxin, interleukin-1, tumor necrosis factor, and transforming growth factor β(TGFβ). The cells are extremely sensitive to TGFβwith maximal effects (100-fold stimulation) observed with 1-2 ng/ml. These changes were relatively specific for PAI-1, and could be detected at both the protein and the RNA level. Interestingly, TGFgalso stimulated the amount of PAI-1 present in the extracellular matrix (ECM) of BAEs. PAI-1 was one of the primary ECM components of these cells, constituting 10-20% of the ECM proteins detected after SDS-PAGE.One of the most unusual properties of PAI-1 is that it exists in blood and in various cellular samples in both an active and an inactive (latent) form, the ratio depending on the source. The latent form can be converted into the active one by treatment with denaturants like SDS or guanidine-HCl. Although the majority of the cell-associated PAI-1 is active, it rapidly decays (t1/2=3 h) into the latent form once it is released from the cells. In contrast, the half-life of ECM associated PAI-1 was greater than 24 h. These data suggest that PAI-1 is produced by BAEs in an active form, and is then either released into the medium where it is rapidly inactivated, or released into the subendothelium where it binds to ECM. The specific binding of PAI-1 to ECM protects it from this inactivation.
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