Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.4.23.15 (renin)
35,795 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Nephrin, a newly described protein, has been localized to the slit membrane between adjacent podocytes of the glomerulus. Its discovery followed the demonstration of the gene NPHS1 and its mutation, resulting in the absence of the protein product, nephrin, in the congenital nephrotic syndrome of the Finnish type. The link between permutations in nephrin expression and proteinuria has been shown in animal models by using neutralizing antibodies or studying mice with inactivation of the nephrin gene. Moreover, the expression of nephrin has been shown to be reduced in various animal models of proteinuric renal disease. The relationship between changes in nephrin expression and proteinuric renal disease in humans is not fully elucidated, with a reduction in expression of this protein reported in a range of renal diseases. Diabetic nephropathy, one of the major causes of end-stage renal disease, is associated with substantial proteinuria and in experimental models with a reduction in slit pore density. In experimental models of diabetes, nephrin expression has been described as being transiently increased in the first 8 weeks of diabetes, followed in longer-term studies with reduced nephrin expression in association with increasing proteinuria. An angiotensin II-receptor blocker has been shown to prevent depletion in glomerular nephrin expression in the diabetic kidney. Human studies in both type 1 and type 2 diabetes suggest down-regulation of nephrin expression in the diabetic kidney and it has been postulated that these changes may play a role in the pathogenesis of diabetic nephropathy, specifically the development of proteinuria in this condition. Although there are other proteins involved in the structure of the epithelial podocyte and specifically the slit pore, nephrin seems to play a pivotal role in preventing passage of protein through the glomerular barrier. Furthermore, it is suggested that the antiproteinuric effects of inhibition of the renin-angiotensin system may partly relate to the effects of these agents on nephrin expression.
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PMID:Role of nephrin in renal disease including diabetic nephropathy. 1222 46

Denys-Drash syndrome (DDS) is caused by dominant mutations of the Wilms' tumour suppressor gene, WT1, and characterized by a nephropathy involving diffuse mesangial sclerosis, male pseudohermaphroditism and/or Wilms' tumourigenesis. Previously, we reported that heterozygosity for the Wt1tmT396 mutation induces DDS in heterozygous and chimeric (Wt1tmT396/+<-->+/+) mice. In the present study, the fate of Wt1 mutant cells in chimeric kidneys was assessed by in situ marker analysis, and immunocytochemistry was used to re-examine the claim that glomerulosclerosis (GS) is caused by loss of WT1 and persistent Pax-2 expression by podocytes. Wt1 mutant cells colonized glomeruli efficiently, including podocytes, but some sclerotic glomeruli contained no detectable Wt1 mutant cells. The development of GS was preceded by widespread loss of ZO-1 signal in podocytes (even in kidneys where <5% of glomeruli contained Wt1 mutant podocytes), increased intra-renal renin expression, and de novo podocyte TGF-beta1 expression, but not podocyte Pax-2 expression or loss of WT1, synaptopodin, alpha-actinin-4 or nephrin expression. However, podocytes in partially sclerotic glomeruli that still expressed WT1 at high levels showed reduced vimentin expression, cell cycle re-entry, and re-expressed desmin, cytokeratin and Pax-2. The results suggest that: (i) GS is not due to loss of WT1 expression by podocytes; (ii) podocyte Pax-2 expression reflects re-expression rather than persistent expression, and is the consequence of GS; (iii) GS is mediated systemically and the mechanism involves activation of the renin-angiotensin system; and (iv) podocytes undergo typical maturational changes but subsequently de-differentiate and revert to an immature phenotype during disease progression.
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PMID:Murine Denys-Drash syndrome: evidence of podocyte de-differentiation and systemic mediation of glomerulosclerosis. 1291 83

Diabetic nephropathy is the most common cause world-wide of renal failure requiring renal replacement therapy, most patients having type 2 rather than type 1 diabetes. Cardiovascular risk increases progressively as nephropathy develops. In addition to abnormalities in the glomerular endothelium and mesangium, recent data suggest that changes are also seen in the glomerular epithelial cell or podocyte. The foot processes of the podocyte broaden and efface and there is loss of podocyte specific proteins such as nephrin. Eventually there is loss of podocytes themselves. These changes may contribute to proteinuria. The development of nephropathy can be prevented by good glucose and blood pressure control. Once microalbuminuria or proteinuria are present, control of intraglomerular pressure, using inhibitors of the renin-angiotensin system, and control of systemic blood pressure are paramount, and can delay the need for renal replacement therapy by many years. Aggressive management of cardiovascular risk factors also slows the progression of nephropathy and prevents cardiovascular events.
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PMID:Recent advances in diabetic nephropathy. 1524 65

Although abnormalities in the glomerular epithelial cell, the podocyte, have been appreciated for some time, it is only recently that their significance and the underlying mechanisms for the changes have begun to be explored. There is a decrease in podocyte number early in diabetes, with further decreases as albuminuria increases. The number of podocytes is inversely related to the degree of albuminuria in both cross-sectional and longitudinal studies. Foot process width is increased in proteinuria, the width correlating with albuminuria. Loss of nephrin - both mRNA and protein - occurs some time after the onset of diabetes and is also inversely related to proteinuria. The amount of the alpha3beta1 integrin on the basement-membrane surface of the foot process of the podocyte is also reduced in diabetes. Loss of nephrin and alpha3beta1 integrin is induced by both hyperglycaemia and mechanical stretch. Agents that inhibit the renin-angiotensin system, but not other agents that reduce proteinuria, restore nephrin expression and prevent the structural changes seen in the podocyte in diabetes. Thus, changes in the podocyte contribute to the proteinuria of diabetic nephropathy and can be ameliorated by inhibition of the renin-angiotensin system.
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PMID:The podocyte: a major player in the development of diabetic nephropathy? 1591 5

Over the last five years, much work has underlined the important role of the podocyte in the development of diabetic nephropathy. The metabolic and haemodynamic abnormalities of the diabetic milieu act in concert, perhaps via the common effector path of oxidative stress and development of reactive oxygen species, to promote podocyte damage. There is loss of nephrin from the slit diaphragm, increased synthesis of some of the components of the glomerular basement membrane, activation of pro-apoptotic and hypertrophic pathways, loss of the alpha3beta1 integrin and increased secretion of VEGF. These changes interact to lead to increased permeability, accumulation of abnormal extracellular matrix, apoptosis, foot process detachment and podocyte loss. The foot processes of the remaining podocytes hypertrophy and widen, with reduced filtration slit width. The end result is increasing proteinuria, basement membrane thickening and accumulation of mesangial matrix and declining renal function. Some currently used therapies, such as tight glucose control and inhibition of the renin angiotensin system, ameliorate these changes and prevent podocyte loss. Statins may also have a specific podocyte protective role. Other potential therapies include inhibitors of glycation, antioxidants, and inhibitors of growth factor and signalling pathways.
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PMID:The podocyte: a potential therapeutic target in diabetic nephropathy? 1789 15

1,25-Dihydroxyvitamin D3 negatively regulates the renin-angiotensin system (RAS), which plays a critical role in the development of diabetic nephropathy. We tested if mice lacking the vitamin D receptor (VDR) are more susceptible to hyperglycemia-induced renal injury. Diabetic VDR knockout mice developed more severe albuminuria and glomerulosclerosis due to increased glomerular basement membrane thickening and podocyte effacement. More fibronectin (FN) and less nephrin were expressed in the VDR knockout mice compared to diabetic wild-type mice. In receptor knockout mice, increased renin, angiotensinogen, transforming growth factor-beta (TGF-beta), and connective tissue growth factor accompanied the more severe renal injury. 1,25-Dihydroxyvitmain D3 inhibited high glucose (HG)-induced FN production in cultured mesangial cells and increased nephrin expression in cultured podocytes. 1,25-Dihydroxyvitmain D3 also suppressed HG-induced activation of the RAS and TGF-beta in mesangial and juxtaglomerular cells. Our study suggests that receptor-mediated vitamin D actions are renoprotective in diabetic nephropathy.
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PMID:Renoprotective role of the vitamin D receptor in diabetic nephropathy. 1816 10

Anti-cancer agent adriamycin (ADR) has demonstrated high anti-tumor efficacy. However, its use in chemotherapy has been limited largely due to its diverse toxicities, including renal toxicity, such as nephrotic syndrome with proteinuria. Podocyte injury leads to glomeruli proteinuria. Wulingsan (WLS) is a blended traditional Chinese herbal medicine specifically used for various kidney diseases. In the present study, we found that a water extract of WLS (480 mg/kg, p.o., x 28 days) reduced ADR-induced increase in urine protein excretion, plasma total cholesterol and triglyceride, and decrease in plasma total protein and albumin in rats. Furthermore, the results of electron microscopy demonstrated suppression by WLS of ADR-induced increase in width of foot process, increase in surface density and decrease in volume density. These results suggest that WLS ameliorates ADR-induced proteinuria and podocyte injury. Gene analysis results demonstrated a suppression of renal overexpression of nephrin mRNA and protein by WLS. Radioimmunoassay showed that WLS suppressed ADR-induced increased renal angiotensin II content in rats. Thus our results demonstrate that WLS ameliorates ADR-induced nephrotic syndrome in rats possibly by suppressing ADR-induced hyperactivity of renal renin-angiotensin system to modulate renal nephrin gene expression, thereby protecting podocyte from injury.
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PMID:Amelioration of anti-cancer agent adriamycin-induced nephrotic syndrome in rats by Wulingsan (Gorei-San), a blended traditional Chinese herbal medicine. 1821 52

The small GTPase RhoA is activated by the angiotensin II (AngII) type 1 receptor (AT1R), which is part of the local renin-angiotensin system that is involved in podocyte injury preceding glomerular crescent formation. We demonstrated previously that inhibition of AT1R protects against crescentic glomerular injury in Fc receptor-deficient mice (gamma -/-) with anti-glomerular basement membrane antibody-induced glomerulonephritis (anti-GBM GN). Here, we hypothesized that the RhoA kinase inhibitor, fasudil, attenuates AT1R-dependent crescentic GN. We examined anti-GBM GN in gamma -/- mice with or without fasudil treatment, and further investigated the underlying mechanisms in cultured differentiated podocytes and leukocytes. Fasudil markedly attenuated crescentic GN with a significant decrease in proteinuria and hematuria, infiltration of T cells and monocytes/macrophages as well as their local proliferation, and preservation of podocyte-specific proteins, including WT-1 and nephrin, in glomeruli. In vitro studies showed that AngII induced the down-regulation of both nephrin and WT-1 expression in podocytes, which was reversed by fasudil in a dose-dependent manner. Additionally, fasudil blocked the AngII-induced migration of both macrophages and T cells. Furthermore, we also examined lipopolysaccharide-induced nephrotic syndrome in severe combined immunodeficiency disease mice and found that fasudil failed to block the development of proteinuria because of a B7-1-dependent podocyte injury. In conclusion, fasudil treatment prevents crescent formation and disease progression in anti-GBM GN by preventing AngII-induced podocyte injury and leukocyte migration.
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PMID:Amelioration of crescentic glomerulonephritis by RhoA kinase inhibitor, Fasudil, through podocyte protection and prevention of leukocyte migration. 1824 10

The renin-angiotensin system (RAS) plays a critical role in the development of diabetic nephropathy, and blockade of the RAS is currently used for treatment of diabetic nephropathy. One major problem for the current RAS inhibitors is the compensatory renin increase, which reduces the efficacy of RAS inhibition. We have shown that vitamin D exerts renoprotective actions by transcriptionally suppressing renin. Here we demonstrated that combination therapy with an AT1 receptor blocker and a vitamin D analog markedly ameliorated renal injury in the streptozotocin (STZ)-induced diabetes model due to the blockade of the compensatory renin rise by the vitamin D analog, leading to more effective RAS inhibition. STZ-treated diabetic DBA/2J mice developed progressive albuminuria and glomerulosclerosis within 13 weeks, accompanied by increased intrarenal production of angiotensin (Ang) II, fibronection, TGF-beta, and MCP-1 and decreased expression of slit diaphragm proteins. Treatment of the diabetic mice with losartan or paricalcitol (19-nor-1,25-dihydroxyvitamin D(2), an activated vitamin D analog) alone moderately ameliorated kidney injury; however, combined treatment with losartan and paricalcitol completely prevented albuminuria, restored glomerular filtration barrier structure, and markedly reduced glomerulosclerosis. The combined treatment suppressed the induction of fibronection, TGF-beta, and MCP-1 and reversed the decline of slit diaphragm proteins nephrin, Neph-1, ZO-1, and alpha-actinin-4. These were accompanied by blockade of intrarenal renin and Ang II accumulation induced by hyperglycemia and losartan. These data demonstrate that inhibition of the RAS with combination of vitamin D analogs and RAS inhibitors effectively prevents renal injury in diabetic nephropathy.
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PMID:Combination therapy with AT1 blocker and vitamin D analog markedly ameliorates diabetic nephropathy: blockade of compensatory renin increase. 1883 78

Recent evidence suggests that mineralocorticoid receptor (MR) antagonism has beneficial effects on tissue oxidative stress and insulin metabolic signaling as well as reducing proteinuria. However, the mechanisms by which MR antagonism corrects both renin-angiotensin-aldosterone system (RAAS) impairments in renal insulin metabolic signaling and filtration barrier/podocyte injury remain unknown. To explore this potential beneficial interactive effect of MR antagonism we used young transgenic (mRen2)27 (Ren2) rats with increased tissue RAAS activity and elevated serum aldosterone levels. Ren2 and age-matched Sprague-Dawley (SD) control rats (age 6-7 wk) were implanted with a low dose of the MR antagonist spironolactone (0.24 mg/day) or vehicle, both delivered over 21 days. Albuminuria, podocyte-specific proteins (synaptopodin, nephrin, and podocin), and ultrastructural analysis of the glomerular filtration barrier were measured in relation to RAAS activation of reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, reactive oxygen species (ROS), and the redox-sensitive Rho kinase (ROK). Insulin metabolic signaling was determined via measurement of insulin receptor substrate-1 (IRS-1) phosphorylation, IRS-1 ubiquitin/proteasomal degradation, and phosphorylation of Akt. Ren2 rats exhibited albuminuria, loss of podocyte-specific proteins, and podocyte foot process effacement contemporaneous with reduced renal IRS-1 and protein kinase B/Akt phosphorylation compared with SD control rats (each P < 0.05). Ren2 kidneys also manifested increased NADPH oxidase/ROS/ROK in conjunction with enhanced renal tissue levels of angiotensin II (ANG II), ANG-(1-12), and angiotensin type 1 receptor. Low-dose spironolactone treatment reduced albuminuria and tissue RAAS activity and improved podocyte structural and protein integrity with improvements in IRS-1/Akt phosphorylation. Thus, in this model of RAAS activation, MR antagonism attenuates glomerular/podocyte remodeling and albuminuria, in part through reductions in redox-mediated impairment of insulin metabolic signaling.
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PMID:Mineralocorticoid receptor antagonism attenuates glomerular filtration barrier remodeling in the transgenic Ren2 rat. 1926 39


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