Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.10.2 (focal adhesion kinase)
 44,029 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The role of hypertension for the combined occurrence of incipient diabetic nephropathy and diabetic retinopathy (RP) was evaluated in 155 insulin-dependent diabetic patients (74 male/81 female); mean age 32.4 +/- 12.2 STD years; means diabetes duration 12.8 +/- 10 STD years). Albumin excretion rate (AER) was measured in 24 hours urine samples by RIA, retinal status was determined by both, fundoscopy and fluorescein angiography. Analysis of the data revealed a statistically significant correlation between the duration of disease and elevated AER (p less than 0.012), and the occurrence of retinopathy (p less than 0.0001). Although there was a close correlation between retinopathy and elevated AER (p less than 0.0001), it is remarkable that 31% of the patients with normal AER (less than 15 micrograms/min) showed signs of non proliferative RP. On the other hand 30% of patients without retinal changes showed an elevated AER (less than 15 micrograms/min). In the group of microalbuminuric patients (greater than 15 micrograms/min) systolic (p less than 0.004) and diastolic (p less than 0.04) blood pressures were significantly higher than in normoalbuminuric patients (less than 15 micrograms/min). Patients with proliferative retinopathy showed significantly higher systolic and diastolic (p less than 0.015) blood pressures compared to patients without retinal changes, though albumin excretion rates were not different in both groups of patients. In conclusion, our results show that diabetic nephropathy and diabetic retinopathy do not develop simultaneously in a representative number of insulin-dependent diabetic patients, but hypertension may be a major risk factor for the development of both microangiopathic complications.
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PMID:[Significance of arterial blood pressure for the development of microalbuminuria and retinopathy in type I diabetes mellitus]. 323 57

The glomerular epithelial cells and the glomerular basement membrane are important constituents of the permselective barrier in the kidney. These are affected in diabetic nephropathy, one of the long-term complications in diabetic patients. Nonenzymatic glycosylation resulting in the accumulation of advanced glycosylation end products correlates with the development of long-term complications in diabetes. The interaction of cells with extracellular matrix proteins plays a critical role in a variety of biological processes. Recent studies show that cell-matrix interactions mediated by integrins can transduce biochemical signals to the cell interior and regulate cell behavior. In this paper we demonstrate that interactions of human glomerular epithelial cells with a nonenzymatically glycated matrix are altered with defective cell spreading, reduced phosphorylation of focal adhesion kinase and reduced activity of mitogen-activated protein kinase. These data suggest that matrix glycation interferes with normal cell-matrix interactions and intracellular signaling that can potentially result in differential gene expression contributing to the changes seen in diabetic nephropathy.
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PMID:Alterations in human glomerular epithelial cells interacting with nonenzymatically glycosylated matrix. 934 47

Based upon the importance of integrins as receptors for extracellular matrix components as well as transducers of extracellular signals, and since major alterations take place in the renal extracellular matrix during diabetes, it is important to study the role played by integrins in the development of the diabetic glomerulosclerosis. Expression of the beta1 subunit by renal glomerular cells was evaluated by biochemical and morphological means in short- and long-term diabetic rats. Western blots of isolated rat renal glomeruli demonstrated that the expression of beta1 increases along with age as well as with the hyperglycaemic state. These changes were significant as early as 6 weeks of hyperglycaemia. This was further demonstrated by immunocytochemistry, which revealed the presence of the beta1 subunit at the level of the plasma membranes of endothelial, epithelial, and mesangial cells. Quantitation of the immunolabelings confirmed the increased expression of beta1 under diabetic conditions. Further to this, expression of the focal adhesion kinase (FAK) was evaluated by immunoblotting showing little increase in diabetic conditions. On the other hand, testing the tyrosine phosphorylation of FAK, revealed significant increases in diabetes. To recover the fraction of FAK associated with the beta1 subunit, immunoprecipitation of isolated glomeruli homogenates was carried out with the anti-beta1 antibody. This demonstrated that the amounts of FAK co-precipitated with beta1, as well as its tyrosine-phosphorylation, are in fact reduced in diabetic conditions. Since the changes reported were observed at time points prior to any morphological alteration of the renal extracellular matrix, it appears that modifications in integrins and in their intracellular relays constitute early events that precede the onset of the diabetic nephropathy and must then be associated with the hyperglycaemic condition.
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PMID:Expression of beta1 integrins in glomerular tissue of Streptozotocin-induced diabetic rats. 1042 88

Advanced glycation end product (AGE) is important in the pathogenesis of diabetic nephropathy, which is characterized by cellular hypertrophy/hyperplasia leading to renal fibrosis. However, the signal transduction pathways of AGE remain poorly understood. The Janus kinase (JAK)/signal transducers and activators of transcription (STAT) pathway has been associated with cellular proliferation in some extra-renal cells. Because interstitial fibroblast proliferation might be important in renal fibrosis, we studied the role of the JAK/STAT pathway in NRK-49F (normal rat kidney fibroblast) cells cultured in AGE/BSA and non-glycated BSA. We showed that AGE dose-dependently (10-200 microgram/ml) increased cellular mitogenesis in NRK-49F cells at 5 and 7 days. However, cellular mitogenesis was unaffected by the simultaneous presence of BSA. Regarding the JAK/STAT pathway, AGE (100 microgram/ml) induced tyrosine phosphorylation of JAK2 (but not JAK1, JAK3 or TYK2) at 15-60 min; it also induced the tyrosine phosphorylation of STAT1 and STAT3 at 1-2 h and 0.5-4 h respectively. Being a transcription factor, AGE also increased the DNA-binding activities of STAT1 and STAT3 AG-490 (a specific JAK2 inhibitor) (5 microM) inhibited tyrosine phosphorylation of JAK2 and the DNA-binding activities of STAT1 and STAT3. The same results were obtained by using specific 'decoy' oligodeoxynucleotides (ODNs) that prevented STAT1 and STAT3 from binding to DNA. Meanwhile, the STAT1 or STAT3 decoy ODN and AG-490 were effective in reversing AGE-induced cellular mitogenesis. We concluded that the JAK2-STAT1/STAT3 signal transduction pathway is necessary for AGE-induced cellular mitogenesis in NRK-49F cells.
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PMID:Role of the Janus kinase (JAK)/signal transducters and activators of transcription (STAT) cascade in advanced glycation end-product-induced cellular mitogenesis in NRK-49F cells. 1043 21

Advanced glycation end-product (AGE) is important in the pathogenesis of diabetic nephropathy (DN), and captopril (an angiotensin converting enzyme inhibitor) is effective in treating this disorder. We have shown that the Janus kinase (JAK)/signal transducers and activators of transcription (STAT) cascade is responsible for AGE-induced mitogenesis in NRK-49F (normal rat kidney fibroblast) cells, but its role in renal fibrosis in DN remains unknown. Therefore, we have sought to determine whether JAK/STAT is involved in AGE-regulated collagen production in NRK-49F cells. We found that AGE time (1-7 days) and dose (10-200 microg/ml)-dependently increased collagen production in these cells. Additionally, AGE increased RAGE (receptor for AGE) protein expression. AGE-induced RAGE expression was dose-dependently inhibited by antisense RAGE oligodeoxynucleotide (ODN) and captopril. AGE-induced type I collagen production and JAK2-STAT1/STAT3 activation were decreased by AG-490 (a specific JAK2 inhibitor), antisense RAGE ODN and captopril. Meanwhile, STAT1 and STAT3 decoy ODNs also suppressed the induction of collagen by AGE. We concluded that RAGE and the JAK2-STAT1/STAT3 pathway were involved in AGE-induced collagen production in NRK-49F cells. Furthermore, captopril was found to reverse AGE-induced collagen production, probably by attenuating RAGE expression and JAK2-STAT1/STAT3 activities.
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PMID:Role of receptor for advanced glycation end-product (RAGE) and the JAK/STAT-signaling pathway in AGE-induced collagen production in NRK-49F cells. 1118 Apr 1

Advanced glycation end products (AGEs) are important in the pathogenesis of diabetic nephropathy, which leads to renal fibrosis. Previously, we found that the janus kinase (JAK)/signal transducers and activators of transcription (STAT) signaling pathway is necessary for AGE-induced cellular proliferation in normal rat kidney interstitial fibroblast (NRK-49F) cells. However, a direct link between JAK/STAT and cell-cycle progression has not been well established. In this regard, STAT5 has been found to induce cyclin D1 and proliferation in hematopoietic cells. Therefore, we examined effects of AGE on STAT5 and cell-cycle-dependent mitogenesis in NRK-49F cells. We found that AGE increased cyclin D1 expression and cyclin-dependent kinase (cdk)4 activity while decreasing p21(WAF1/CIP1) expression. We also found that AGE (100 microg/mL) induced STAT5 tyrosine phosphorylation. Meanwhile, AGE induced STAT5 protein-DNA binding activity, which was reversed by AG-490 (a specific JAK2 inhibitor) and STAT5 decoy oligodeoxynucleotide (ODN). In addition, STAT5 decoy ODN reversed AGE-induced cell-cycle-dependent cellular proliferation and cyclin D1 protein expression. We concluded that AGE induced cell-cycle-dependent cellular proliferation by inducing the JAK2-STAT5-cyclin D1 and cdk4 pathways in NRK-49F cells.
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PMID:Advanced glycation end product-induced proliferation in NRK-49F cells is dependent on the JAK2/STAT5 pathway and cyclin D1. 1168 65

Tensin, a focal adhesion protein, is expressed in renal tubular epithelial cells (TECs). Tensin-null mice develop multiple large cysts in the renal proximal tubules. However, the role of tensin in human glomeruli remains unclear. In this study, we assessed tensin localization in human kidney and interaction between tensin and other adhesion components. In human mesangial cells (MCs) and TECs, we confirmed mRNA and protein expressions of tensin by RT-PCR and immunoprecipitation. In normal kidney, immunohistochemistry revealed that tensin was localized in MCs and parietal epithelial cells as well as TECs. In biopsy specimens, the expression of tensin was significantly increased in areas of mesangial expansion in patients with IgA nephropathy and diabetic nephropathy. These results suggest that the expression of tensin is associated with extracellular matrix (ECM) production. In vitro, immunocytochemistry revealed that MCs express tensin mainly at the ends of actin stress fibers and apparently in the focal adhesion areas. Integrin alpha5, but not alpha1 and alpha3, colocalized with tensin. Vinculin and focal adhesion kinase (FAK) were coprecipitated by tensin, suggesting that tensin can mediate signal transduction between cell and ECM through these molecules. Tensin may play important roles in mesangial ECM production through an adhesion complex with integrin alpha5, FAK, and vinculin.
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PMID:Tensin is potentially involved in extracellular matrix production in mesangial cells. 1499 32

Connective tissue growth factor [CTGF]/CCN2 is a prototypic member of the CCN family of regulatory proteins. CTGF expression is up-regulated in a number of fibrotic diseases, including diabetic nephropathy, where it is believed to act as a downstream mediator of TGF-beta function; however, the exact mechanisms whereby CTGF mediates its effects remain unclear. Here, we describe the role of CTGF in cell migration and actin disassembly in human mesangial cells, a primary target in the development of renal glomerulosclerosis. The addition of CTGF to primary mesangial cells induced cell migration and cytoskeletal rearrangement but had no effect on cell proliferation. Cytoskeletal rearrangement was associated with a loss of focal adhesions, involving tyrosine dephosphorylation of focal adhesion kinase and paxillin, increased activity of the protein tyrosine phosphatase SHP-2, with a concomitant decrease in RhoA and Rac1 activity. Conversely, Cdc42 activity was increased by CTGF. These functional responses were associated with the phosphorylation and translocation of protein kinase C-zeta to the leading edge of migrating cells. Inhibition of CTGF-induced protein kinase C-zeta activity with a myristolated PKC-zeta inhibitor prevented cell migration. Moreover, transient transfection of human mesangial cells with a PKC-zeta kinase inactive mutant (dominant negative) expression vector also led to a decrease in CTGF-induced migration compared with wild-type. Furthermore, CTGF stimulated phosphorylation and activation of GSK-3beta. These data highlight for the first time an integrated mechanism whereby CTGF regulates cell migration through facilitative actin cytoskeleton disassembly, which is mediated by dephosphorylation of focal adhesion kinase and paxillin, loss of RhoA activity, activation of Cdc42, and phosphorylation of PKC-zeta and GSK-3beta. These changes indicate that the initial stages of CTGF mediated mesangial cell migration are similar to those involved in the process of cell polarization. These findings begin to shed mechanistic light on the renal diabetic milieu, where increased CTGF expression in the glomerulus contributes to cellular dysfunction.
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PMID:Connective tissue growth factor [CTGF]/CCN2 stimulates mesangial cell migration through integrated dissolution of focal adhesion complexes and activation of cell polarization. 1531 69

Diabetic nephropathy (DN) is characterized by glomerulopathy and tubulointerstitial expansion followed by renal fibrosis. Angiotensin II (Ang II) and connective tissue growth factor (CTGF) are involved in the pathogenesis of DN, while Janus kinase 2 (JAK2) is important in advanced glycation end-product (AGE)-induced effects in renal interstitial (NRK-49F) fibroblasts. Thus, we studied the role of Ang II, CTGF, and JAK2 in AGE-induced effects in NRK-49F cells. We found that AGE (150 microg/ml) increased mitogenesis and type I collagen production at 7 days while Ang II (10(-7)M) increased mitogenesis and type I collagen production at 3 days. We also found that AGE (150 microg/ml) increased angiotensinogen protein at 2 days, which was attenuated by AG-490 (a JAK2 inhibitor). AGE (150 microg/ml) increased CTGF mRNA and protein expression at 3 and 5 days, respectively. Ang II (10(-7)M) increased CTGF mRNA and protein expression at 1 and 2 days, respectively, which were attenuated by AG-490. Moreover, losartan (a type I angiotensin receptor blocker) and captopril (an angiotensin converting enzyme inhibitor) attenuated AGE-induced CTGF mRNA/protein expression while attenuating AGE-induced mitogenesis and type I collagen production. AG-490 and CTGF antisense (but not sense) oligodeoxynucleotide (ODN) attenuated Ang II (10(-7)M) and AGE-induced mitogenesis and type I collagen production at 3 and 7 days, respectively. We concluded that AGE (150 microg/ml)-induced mitogenesis and type I collagen production are dependent on the Ang II-JAK2-CTGF pathway in NRK-49F cells. Moreover, Ang II-induced mitogenesis and type I collagen production are dependent on the JAK2-CTGF pathway.
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PMID:Advanced glycation end-product-induced mitogenesis and collagen production are dependent on angiotensin II and connective tissue growth factor in NRK-49F cells. 1577 Jun 49

Renal interstitial fibrosis is believed to play a key role in the development of diabetic nephropathy (DN), and advanced glycation end-products (AGE) may contribute importantly to this. Recent reports have shown that nitric oxide (NO) is closely linked to the renal interstitial fibrosis of DN. In this study, the mechanisms by which NO and its downstream signals mediate the AGE-induced proliferative response in normal rat kidney fibroblasts (NRK-49F) are examined. AGE decreased NO production, cyclic guanosine 5'monophosphate (cGMP) synthesis, and cGMP-dependent protein kinase (PKG) activation time- and dose-dependently. These effects were not observed when cells were treated with nonglycated BSA. NO and inducible nitric oxide synthase (iNOS) stimulated by NO donors S-nitroso-N-acetylpenicillamine (SNAP)/sodium nitroprusside (SNP) and PKG activator 8-para-chlorophenylthio-cGMP (8-pCPT-cGMP) prevented both AGE-induced proliferation and Janus kinase 2 (JAK2)-signal transducers and activators of transcription 5 (STAT5) activation but not p42/p44 mitogen-activated protein kinase (MAPK) activation. The ability of NO-PKG to inhibit AGE-induced cell cycle progression was verified by the observation that SNAP, SNP, and 8-pCPT-cGMP inhibited both cyclin D1 and cdk4 activation. Furthermore, induction of NO-PKG significantly increased p21Waf1/Cip1 expression in AGE-treated NRK-49F cells. The data suggest that the NO-PKG pathway inhibits AGE-induced proliferation by suppressing activation of JAK2-STAT5 and cyclin D1/cdk4 and induction of p21Waf1/Cip1.
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PMID:Effect of nitric oxide-cGMP-dependent protein kinase activation on advanced glycation end-product-induced proliferation in renal fibroblasts. 1595 24


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