Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0948265 (metabolic syndrome)
 24,271 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Metabolic syndrome is an important risk factor for proteinuria and chronic kidney disease independent of diabetes and hypertension; however, the underlying mechanisms have not been elucidated. Aldosterone is implicated in target organ injury of obesity-related disorders. This study investigated the role of aldosterone in the early nephropathy of 17-wk-old SHR/NDmcr-cp, a rat model of metabolic syndrome. Proteinuria was prominent in SHR/NDmcr-cp compared with nonobese SHR, which was accompanied by podocyte injury as evidenced by foot process effacement, induction of desmin and attenuation of nephrin. Serum aldosterone level, renal and glomerular expressions of aldosterone effector kinase Sgk1, and oxidative stress markers all were elevated in SHR/NDmcr-cp. Mineralocorticoid receptors were expressed in glomerular podocytes. Eplerenone, a selective aldosterone blocker, effectively improved podocyte damage, proteinuria, Sgk1, and oxidant stress. An antioxidant tempol also alleviated podocyte impairment and proteinuria, along with inhibition of Sgk1. As for the mechanisms of aldosterone excess, visceral adipocytes that were isolated from SHR/NDmcr-cp secreted substances that stimulate aldosterone production in adrenocortical cells. The aldosterone-releasing activity of adipocytes was not inhibited by candesartan. Adipocytes from nonobese SHR did not show such activity. In conclusion, SHR/NDmcr-cp exhibit enhanced aldosterone signaling, podocyte injury, and proteinuria, which are ameliorated by eplerenone or tempol. The data also suggest that adipocyte-derived factors other than angiotensin II might contribute to the aldosterone excess of this model.
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PMID:Enhanced aldosterone signaling in the early nephropathy of rats with metabolic syndrome: possible contribution of fat-derived factors. 1708 36

Diabetic nephropathy is the leading cause of renal failure in the United States. The obese Zucker rat (OZR; fa/fa) is a commonly used model of type 2 diabetes and metabolic syndrome (MetS), and of the nephropathy and renal oxidative stress commonly seen in these disorders. Heterozygous lean Zucker rats (LZRs; fa/+) are susceptible to high-fat diet (HFD)-induced obesity and MetS. The present study was designed to investigate whether 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl (TEMPOL), a membrane-permeable radical scavenger, could alleviate the renal effects of MetS in OZR and LZR fed a HFD, which resembles the typical "Western" diet. OZR and LZR were fed a HFD (OZR-HFD and LZR-HFD) or regular diet (OZR-RD and LZR-RD) and allowed free access to drinking water or water containing 1 mmol/l TEMPOL for 10 weeks. When compared to OZR-RD animals, OZR-HFD animals exhibited significantly higher levels of total renal cortical reactive oxygen species (ROS) production, plasma lipids, insulin, C-reactive protein, blood urea nitrogen (BUN), creatinine (Cr), and urinary albumin excretion (P < 0.05); these changes were accompanied by a significant decrease in plasma high-density lipoprotein levels (P < 0.05). The mRNA expression levels of desmin, tumor necrosis factor-alpha (TNF-alpha), nuclear factor kappaB (NFkappaB), and NAD(P)H oxidase-1 (NOX-1) were significantly higher in the renal cortical tissues of OZR-HFD animals; NFkappaB p65 DNA binding activity as determined by electrophoretic mobility shift assay was also significantly higher in these animals. The same trends were noted in LZR-HFD animals. Our data demonstrate that TEMPOL may prove beneficial in treating the early stages of the nephropathy often associated with MetS.
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PMID:Diet-induced renal changes in Zucker rats are ameliorated by the superoxide dismutase mimetic TEMPOL. 1942 63

Metabolic syndrome (MS) is an independent risk factor for chronic kidney diseases. As the renin-angiotensin system (RAS) is known to have a key role in renal damage, blockade of RAS may show renoprotective effects in MS. In this study, we investigated the renoprotective effects and mechanisms of action of an angiotensin receptor blocker (ARB) in spontaneously hypertensive (SHR/NDmcr-cp) rats as a model of MS. Male SHR/NDmcr-cp rats at 9 weeks of age were divided into three groups, each of which was treated for 12 weeks with vehicle, hydralazine (7.5 mg kg(-1) per day, p.o.) or ARB (olmesartan, 5 mg kg(-1) per day, p.o.). Blood pressure and urinary protein (UP) excretion were monitored. Kidney tissues were subjected to histological, immunohistochemical and molecular analyses. UP excretion increased with age in vehicle-treated SHR/NDmcr-cp rats compared with that in age-matched WKY/Izm rats. In addition, there was significant glomerular damage (increased glomerular sclerosis index, desmin staining and proliferating cell nuclear antigen (PCNA)-positive cells, electron microscopic findings of podocyte injury) and tubulointerstitial damage (increased tubulointerstitial fibrosis index, type IV collagen staining, PCNA-positive cells and expression of TGF-beta mRNA) in vehicle-treated SHR/NDmcr-cp rats compared with that in control rats. All the findings that related to glomerular and tubulointerstitial damage were significantly improved by ARB. Hydralazine mitigated the observed renal damage but was much less effective than ARB, despite similar decreases in blood pressure. There were no significant differences in glucose and lipid metabolism among vehicle-treated, hydralazine-treated and ARB-treated SHR/NDmcr-cp animals. These data suggest that RAS is deeply involved in the pathogenesis of renal damage in MS, and ARBs could provide a powerful renoprotective regimen for patients with MS.
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PMID:Renoprotective effects of an angiotensin II receptor blocker in experimental model rats with hypertension and metabolic disorders. 1966 21

Metabolic syndrome increases the risk of developing diabetes as well as cardiovascular and kidney diseases. This research studied the effects of tesaglitazar, a dual-acting peroxisome proliferator-activated receptor (PPAR)alpha/gamma agonist, on metabolic abnormalities and kidney injury in obese Zucker rats (OZR). Lean Zucker rats (LZR) and OZR were used as control groups. Tesaglitazar (1 micromol/kg/day) was given for 8 weeks in the treatment group (OZR-T). Metabolic parameters, 24-hour urine albumin excretion, and tail blood pressure were measured. Glomerular filtration rate by inulin clearance, abdominal fat and renal histology were determined at the end of the study. In comparison with the OZR and OZR-T groups, the LZR control animals' parameters were significantly more favorable in all measures. Tesaglitazar treatment in OZR significantly reduced nonfasting glucose, C-reactive protein levels and improved dyslipidemia. Body weight, blood pressure and urine albumin excretion were lower, but the adjusted glomerular filtration rate higher, in the OZR-T group than in the OZR controls. Glomerular area, mesangial expansion and tubulointerstitial changes were ameliorated, and the glomerular expression of desmin was markedly more decreased in the OZR-T group than in the OZR controls. Therefore, the PPAR alpha/gamma agonist tesaglitazar significantly improved metabolic abnormalities and renal function, decreased blood pressure, and protected against glomerular and interstitial damage in OZR.
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PMID:Tesaglitazar, a dual peroxisome proliferator-activated receptor agonist (PPAR alpha/gamma), improves metabolic abnormalities and reduces renal injury in obese Zucker rats. 1988 47

The present study tested a hypothesis that excess accumulation of sphingolipid, ceramide, its metabolites, or a combination contributes to the development of obesity and associated kidney damage. Liquid chromatography/mass spectrometry analysis demonstrated that C57BL/6J mice on the high-fat diet (HFD) had significantly increased plasma total ceramide levels compared with animals fed a low-fat diet (LFD). Treatment of mice with the acid sphingomyelinase (ASMase) inhibitor amitriptyline significantly attenuated the HFD-induced plasma ceramide levels. Corresponding to increase in plasma ceramide, the HFD significantly increased the body weight gain, plasma leptin concentration, urinary total protein and albumin excretion, glomerular damage index, and adipose tissue ASMase activity compared with the LFD-fed mice. These HFD-induced changes were also significantly attenuated by treatment of mice with amitriptyline. In addition, the decline of plasma glucose concentration after an intraperitoneal injection of insulin (0.15 U/kg b.wt.) was more sustained in mice on the HFD with amitriptyline than on the HFD alone. Intraperitoneal injection of glucose (3 g/kg b.wt.) resulted in a slow increase followed by a rapid decrease in the plasma glucose concentration in LFD and HFD plus amitriptyline-treated mice, but such blood glucose response was not observed in HFD-fed mice. Immunofluorescence analysis demonstrated a decrease in the podocin and an increase in the desmin in the glomeruli of HFD-fed mice compared with the LFD and HFD plus amitriptyline-treated mice. In conclusion, our results reveal a pivotal role for ceramide biosynthesis in obesity, metabolic syndrome, and associated kidney damage.
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PMID:Role of sphingolipid mediator ceramide in obesity and renal injury in mice fed a high-fat diet. 2054 95

The mechanisms underlying insulin sensitivity and fat tissue distribution in chronic renal insufficiency remain unclear. Previous studies have shown the benefits of angiotensin II receptor blockers on moderately nourished to well-nourished patients with the metabolic syndrome. The current study explored the effect of losartan, the first selective angiotensin II receptor blocker, on insulin sensitivity and visceral fat tissue distribution in a 5/6 nephrectomized (N) rat model and investigated the expression of adipose tissue adipocytokines. Male Sprague-Dawley rats (200 g to 250 g) were subjected to 5/6 nephrectomy, and the adipocytes isolated from the visceral fat tissues were then studied. Results showed that desmin expression was significantly suppressed and systolic blood pressure was successfully normalized in the losartan-administered (NA) group. The weight of the visceral fat pad remarkably decreased in the N and NA groups (100 mg/500 ml drinking water) compared with the control group. The weight did not decrease further in the NA group compared with the N group. Insulin resistance was more remarkable in the N group compared with the control and NA groups. Moreover, the adipose tissue expression of adiponectin and leptin was downregulated whereas that of resistin was upregulated in the N group compared with the control group. However, the adiponectin, leptin, and resistin adipose tissue expression returned to their basal values in the NA group. These findings indicated that losartan administration ameliorated renal injury, systolic blood pressure, and adipocytokine imbalance of the adipose tissue in chronic renal insufficiency. Insulin sensitivity was not improved.
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PMID:Losartan ameliorates renal injury, hypertension, and adipocytokine imbalance in 5/6 nephrectomized rats. 2352 57