Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0011860 (type 2 diabetes)
 57,723 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Autocrine activation of the IGF-I system in mesangial cells (MC) promotes glomerular scarring in a model of type 1 diabetes. Although estrogens protect against progressive nondiabetic glomerulosclerosis (GS), women with diabetes seem to loose the estrogen-mediated protection against cardiovascular disease. However, little is known about the local IGF-I system and its interactions with estrogens in the pathogenesis of type 2 diabetic GS. Therefore, we examined db/db B6 (db/db) mice, a model of type 2 diabetes and diabetic GS. The IGF-I system was activated in the glomeruli and MC of female diabetic db/db mice, but not in nondiabetic db/+ littermates. We found increased IGF-I receptor (IGFR) expression and activation, including activation of MAPK. Surprisingly, estrogens, via an estrogen receptor (ER)-independent mechanism(s), increased IGFR expression, IGFR and insulin receptor substrate phosphorylation, and extracellular signal-regulated kinase activation in db/db MC. In contrast, ER expression was decreased in MC and glomeruli of db/db mice. Treatment with a neutralizing antibody to IGF-I or the MAPK inhibitor PD98059 increased ER expression and transcriptional activity. This suggests that the local prosclerotic IGF-I system is activated in type 2 diabetes and diminishes ER-mediated protection against GS. Although estrogens may stimulate protective ER signaling, they also activate the IGF-I system via ER-independent mechanisms in db/db MC. The later estrogen effects appear to outweigh the antisclerotic effects of ER activation. This may in part account for loss of estrogen protection against the progression of diabetic GS in women with type 2 diabetes.
 ...
PMID:Autocrine activation of the local insulin-like growth factor I system is up-regulated by estrogen receptor (ER)-independent estrogen actions and accounts for decreased ER expression in type 2 diabetic mesangial cells. 1555 May 5

The aim of the study was to analyze the etiology, the factors for progression of chronic renal failure to end-stage-renal disease (ESRD), and the influence of ESRD on the survival rate among a cohort of 59 heart transplant patients (HTP) referred for the management of chronic renal failure (CRF). At the time of the first nephrology consultation (6 +/- 4.25 years after cardiac transplantation) the mean creatininemia was 261.5 +/- 99 micromol/L and mean creatinine clearance (Cockcroft formula) was 32 +/- 15 mL/min. The cause of CRF were calcineurin inhibitor toxicity in 38.9% of patients, vascular events in 15.2%, hemolytic uremic syndrome in 5%, membranous glomerulopathy in 3.3%, diabetes in two patients, focal/segmental glomerulosclerosis in 3.3%, renal hypoplasia in 1.7%, and unknown in 27%. Evolution to ESRD occurred in 38.9% of patients: 17 patients started hemodialysis, three peritoneal dialysis, and two received a preemptive kidney transplantation. Creatininemia (micromol/L) at the time of nephrology referral was 229.2 +/- 72.6 versus 315.8 +/- 113.4 (P < .001) and creatinine clearance (mL/min) was 34.9 +/- 15.1 versus 27.3 +/- 13.7 (P = .049) for patients with CRF versus ESRD, respectively. Both proteinuria (g/24 hours) of 1 +/- 2.2 versus 2.3 +/- 1.8 (P = .02) and tobacco use in 35.1% versus 54.4% (P = .045) were significantly associated with progression of CRF, while age at the time of heart transplantation, cause of cardiac failure and renal failure, high blood pressure, type 2 diabetes, dyslipidemia, alcoholism, cirrhosis, and cerebral vascular accident were not. Death occurred in 18 HTP: 50% of patients with ESRD and 18.5% of patients with CRF-a 2.6 relative risk of of death in HTP patients with ESRD compared with HTP with CRF only (P < .01).
 ...
PMID:Chronic renal failure and end-stage renal disease are associated with a high rate of mortality after heart transplantation. 1584 18

Diabetic kidney disease has been associated with the presence of lipid deposits, but the mechanisms for the lipid accumulation have not been fully determined. In the present study, we found that db/db mice on the FVB genetic background with loss-of-function mutation of the leptin receptor (FVB-Lepr(db) mice or FVBdb/db) develop severe diabetic nephropathy, including glomerulosclerosis, tubulointerstitial fibrosis, increased expression of type IV collagen and fibronectin, and proteinuria, which is associated with increased renal mRNA abundance of transforming growth factor-beta, plasminogen activator inhibitor-1, and vascular endothelial growth factor. Electron microscopy demonstrates increases in glomerular basement membrane thickness and foot process (podocyte) length. We found that there is a marked increase in neutral lipid deposits in glomeruli and tubules by oil red O staining and biochemical analysis for cholesterol and triglycerides. We also detected a significant increase in the renal expression of adipocyte differentiation-related protein (adipophilin), a marker of cytoplasmic lipid droplets. We examined the expression of sterol regulatory element-binding protein (SREBP)-1 and -2, transcriptional factors that play an important role in the regulation of fatty acid, triglyceride, and cholesterol synthesis. We found significant increases in SREBP-1 and -2 protein levels in nuclear extracts from the kidneys of FVBdb/db mice, with increases in the mRNA abundance of acetyl-CoA carboxylase, fatty acid synthase, and 3-hydroxy-3-methylglutaryl-CoA reductase, which mediates the increase in renal triglyceride and cholesterol content. Our results indicate that in FVBdb/db mice, renal triglyceride and cholesterol accumulation is mediated by increased activity of SREBP-1 and -2. Based on our previous results with transgenic mice overexpressing SREBP-1 in the kidney, we propose that increased expression of SREBPs plays an important role in causing renal lipid accumulation, glomerulosclerosis, tubulointerstitial fibrosis, and proteinuria in mice with type 2 diabetes.
 ...
PMID:Regulation of renal lipid metabolism, lipid accumulation, and glomerulosclerosis in FVBdb/db mice with type 2 diabetes. 1604 98

Diabetic nephropathy characterized by proteinuria and sclerosis is the leading cause of renal failure, but its mechanisms are not well understood. Zucker Obese (ZO) rat model of obesity, insulin resistance, and hypertension has been used to study nephropathy. We hypothesize that chronically elevated intrarenal angiotensin II (ANG II) down-regulates nephrin, a key slit-pore protein and up-regulates fibrogenic molecule transforming growth factor (TGFbeta1) and thus result in progression of nephropathy in type 2 diabetes. Untreated or angiotensin converting enzyme (ACE) inhibitor, captopril, treated ZO and control Lean (ZL) rats were used to measure intrarenal levels of ANG II, glomerular nephrin, TGFbeta1, collagen and fibronectin with age using radioimmunoassay, RT-PCR and immunoblot techniques. Progression of nephropathy was established by measuring proteinuria and sclerosis. ZO rats developed obesity, hyperglycemia, hyperinsulinimia, increase in intrarenal ANG II and proteinuria. Expression of glomerular nephrin decreased while expression of TGFbeta1 and matrix components increased in ZO rats. Captopril treatment prevented increase in intrarenal ANG II, and reversed expression of nephrin, TGFbeta1, collagen and fibronectin. We conclude that in this model of type 2 diabetic nephropathy, chronically elevated intrarenal ANG II causes proteinuria via decrease in nephrin and glomerulosclerosis via TGFbeta1 mediated increase in matrix component.
 ...
PMID:Chronically increased intrarenal angiotensin II causes nephropathy in an animal model of type 2 diabetes. 1614 87

Type 2 diabetes mellitus has reached epidemic proportions and diabetic nephropathy is the leading cause of end-stage renal disease. The metabolic syndrome constitutes a milieu conducive to tissue redox stress. This loss of redox homeostasis contributes to renal remodeling and parallels the concurrent increased vascular redox stress associated with the cardiometabolic syndrome. The multiple metabolic toxicities, redox stress and endothelial dysfunction combine to weave the complicated mosaic fabric of diabetic glomerulosclerosis and diabetic nephropathy. A better understanding may provide both the clinician and researcher tools to unravel this complicated disease process. Cellular remodeling of podocyte foot processes in the Ren-2 transgenic rat model of tissue angiotensin II overexpression (TG(mREN-2)27) and the Zucker diabetic fatty model of type 2 diabetes mellitus have been observed in preliminary studies. Importantly, angiotensin II receptor blockers have been shown to abrogate these ultrastructural changes in the foot processes of the podocyte in preliminary studies. An integrated, global risk reduction, approach in therapy addressing the multiple metabolic abnormalities combined with attempts to reach therapeutic goals at an earlier stage could have a profound effect on the development and progressive nature to end-stage renal disease and ultimately renal replacement therapy.
 ...
PMID:Renal redox stress and remodeling in metabolic syndrome, type 2 diabetes mellitus, and diabetic nephropathy: paying homage to the podocyte. 1621 Aug 38

Diabetic nephropathy is currently the most common cause of end-stage renal disease. Diabetic nephropathy patients, whether insulin dependent or not, develop fibrotic changes in glomeruli that manifest as overt nephropathy. Previously, we demonstrated that 5-chloro-2-{(1E)-3-[2-(4-methoxybenzoyl)-4-methyl-1H-pyrrol-1-yl]prop-1-en-1-yl}-N-(methylsulfonyl)benzamide (SMP-534) reduces extracellular matrix (ECM) production induced by transforming growth factor-beta (TGF-beta) in vitro and prevents the accumulation of ECM in glomeruli in rat Thy-1 nephritis models. In this study, we examined the long-term effects of SMP-534 on renal insufficiency and glomerulosclerosis in db/db mice, which are models of type 2 diabetes. A diet containing SMP-534 was given to the mice from the age of 9 to 25 wk, and blood and urine analysis were performed at 8, 17, and 25 wk. At the end of study, kidney tissues were analyzed histologically. Treatment with SMP-534 dose dependently suppressed the increase of urinary albumin and type IV collagen excretion in db/db mice. The renal histological analysis showed that SMP-534 dose dependently suppressed the increase of mesangial expansion in the kidney. In the immunohistological analysis, fibronectin and type IV collagen expression were lower in SMP-534-treated db/db mice compared with vehicle-treated db/db mice. This study suggested that SMP-534 ameliorated the increase of ECM production in kidney of db/db mice, possibly through the inhibition of TGF-beta action. Hence, antifibrotic agents such as SMP-534 might be a new therapeutic option for the treatment of diabetic nephropathy.
 ...
PMID:SMP-534 ameliorates progression of glomerular fibrosis and urinary albumin in diabetic db/db mice. 1627 77

The development of angiotensin receptor blockers (ARBs) has resulted in effective oral treatment for hypertension. One of the most recent members of this therapeutic class is olmesartan medoxomil (OM). The active metabolite, olmesartan, produces insurmountable AT1 receptor blockade and dose-dependently reduces BP. In both experimental and clinical studies, ARBs have been shown to exert renoprotective effects in addition to antihypertensive activity. In an SHR model of hypertensive renal injury, OM (3.0 and 10.0 mg/kg/day) dose-dependently reduced BP but also reduced urinary protein excretion by 65% and 75%, respectively (P < 0.05). Similar doses of OM, in a DOCA-salt hypertensive rat model, did not affect BP but reduced urinary protein excretion by 26% and 39% when compared to control hypertensive animals (P < 0.05). Hypertension is a major pathophysiological determinant of progressive arterial damage that can accelerate the development of diabetic nephropathy. At doses of 0.6 and 6.0 mg/kg/day, OM significantly reduces hypertension associated with type 2 diabetes. These doses of OM reduced BP and dose-dependently reduced proteinuria 31% and 76%, respectively, in hypertensive ZDF rats (P < 0.01). OM also reduced renocortical and renomedulla injury by 19% and 50% at doses of 0.6 and 6.0 mg/kg/day. The glomerular sclerosis index (GSI) was also reduced by 25% and 37% (P < 0.05). Thus, OM improves both functional and morphologic damage associated with diabetic nephropathy. These studies demonstrate that OM, a potent ARB, dose-dependently reduces BP and also provides a dose-related nephroprotective effect in animal models of diabetes. These studies show that the antihypertensive affect of OM is renoprotective but suggest that these renal benefits may also occur independently from a reduction in BP. A further evaluation of the effects of OM in diabetes is warranted.
 ...
PMID:The angiotensin-II (AT-II) receptor blocker olmesartan reduces renal damage in animal models of hypertension and diabetes. 1641 56

Neuronal nitric oxide synthase (nNOS) and cyclooxygenase-2 (COX-2) regulate the tubuloglomerular feedback (TGF) and renin-angiotensin system (RAS) in the kidney. In type 1 diabetic rats, renal overproduction of these enzymes and their relationship to the pathogenesis of diabetic nephropathy has been demonstrated. In the present study, we histologically and immunohistochemically investigated the kidneys of Otsuka Long-Evans Tokushima Fatty (OLETF) rats, as a model of type 2 diabetes, at 62 weeks of age (chronic phase of diabetes). The kidneys of OLETF rats showed typical diabetic nephropathy. Quantitative scores for glomerulosclerosis and interstitial fibrosis in OLETF rats were significantly higher than those of age-matched control Long-Evans Tokushima Otsuka (LETO) rats. nNOS- and COX-2-positive immunoreactions were observed in the distal tubules and collecting ducts. These reactions appeared to be more widely distributed in OLETF, and the number of nNOS-and COX-2-positive sites in the OLETF were significantly more than those in LETO rats. Expression of renin, angiotensin II, and inducible nitric oxide synthase (iNOS) were also examined immunohistochemically, and no differences between OLETF and LETO rats were observed in the distributions and the number of immunoreactive-sites. In conclusion, the overproduction of nNOS and COX-2 in the kidney of OLETF rats was confirmed, suggesting that the overproduction of nNOS and/or COX-2 does not affect the intrarenal RAS or iNOS production but does affect TGF.
 ...
PMID:Neuronal nitric oxide synthase and cyclooxygenase-2 in diabetic nephropathy of type 2 diabetic OLETF rats. 1650 8

Renal involvement in type 2 diabetes is a well known clinical occurrence. According to data from the literature, besides diabetic glomerulosclerosis, type 2 diabetic nephropathy may occur as a non specific chronic damage mostly related to vascular changes, or as a glomerular disease superimposed on or even unrelated to diabetic glomerulosclerosis. The most common picture remains in any case diabetic glomerulosclerosis (diabetic GS), that is characterized by variable degrees of mesangial sclerosis.
 ...
PMID:Histopathological atlas of renal diseases: diabetic nephropathy. 1652 18

Leptin is a peptide hormone that is mainly, but not exclusively, produced in adipose tissue and plays a pivotal role in regulating food intake and energy expenditure. Besides its effects on regulation of body weight, appetite and energy expenditure, leptin exhibits influence on the immune system and may contribute to the deterioration of renal function. These direct and indirect renal effects of leptin could partly explain obesity-associated kidney disease and may be also relevant for diabetic nephropathy in type 2 diabetes. Leptin is primarily metabolized in the kidney, presumably by binding to megalin, a multiligand receptor in the proximal tubule, tubular uptake and endocytosis. The kidney expresses abundant concentrations of the small isoform of the leptin receptor (Ob-Ra). In cultured renal rat endothelial cells and mesangial cells obtained from db/db mice, leptin can signal through the Ob-Ra receptor isoform. The peptide stimulates proliferation of glomerular endothelial cells, increases TGF-beta1 synthesis, and collagen type IV production. In contrast, leptin did not influence TGF-beta1 production in mesangial cells, but the peptide stimulates glucose transport in these cells, increased collagen type I synthesis, and lead to an upregulation of surface TGF-beta type II receptors through signal transduction pathways involving phosphatidylinositol-3-kinase. Leptin also stimulates hypertrophy, but not proliferation in cultured rat mesangial cells. Infusion of leptin for 3 weeks into normal rats fosters development of glomerulosclerosis and proteinuria. In addition, transgenic mice with leptin overexpression demonstrated a increase in collagen type IV and fibronectin mRNA in the kidney. Additional previously described direct and indirect effects of leptin on the kidney include natriuretic effects, an increase in sympathetic nervous activity, and stimulation of reactive oxygen species. These findings collectively suggest that the kidney is a target organ for leptin and that this hormone might play an important role in renal pathophysiology.
 ...
PMID:Leptin and renal fibrosis. 1692 41


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>