scholarly journals Lovastatin Inhibits Transforming Growth Factor-β1 Expression in Diabetic Rat Glomeruli and Cultured Rat Mesangial Cells

2000 ◽  
Vol 11 (1) ◽  
pp. 80-87
Author(s):  
SUNG IL KIM ◽  
DONG CHEOL HAN ◽  
HI BAHL LEE
Keyword(s):  
Diabetic Nephropathy ◽  
Blood Glucose ◽  
Transforming Growth Factor ◽  
Mesangial Cells ◽  
Diabetic Rats ◽  
Kidney Weight ◽  
Urine Albumin Excretion ◽  
Urine Albumin ◽  
Ecm Proteins ◽  
Tgf Β1

Abstract. Diabetic nephropathy is a leading cause of end-stage renal disease and is characterized by excessive deposition of extracellular matrix (ECM) proteins in the glomeruli. Transforming growth factor-β (TGF-β) is the major mediator of excessive accumulation of ECM proteins in diabetic nephropathy through upregulation of genes encoding ECM proteins as well as downregulation of genes for ECM-degrading enzymes. It has been shown that lovastatin, an inhibitor of 3-hydroxy-3-methylglutaryl CoA reductase, delays the onset and progression of different models of experimental nephropathy. To evaluate the effect of lovastatin on the development and progression of diabetic nephropathy, streptozotocin-induced diabetic rats were studied for 12 mo. In untreated diabetic rats, there were significant increases in blood glucose, urine albumin excretion, kidney weight, glomerular volume, and TGF-β1 mRNA expression in the glomeruli compared with normal control rats treated with citrate buffer only. Treatment with lovastatin in diabetic rats significantly suppressed the increase in urine albumin excretion, kidney weight, glomerular volume, and TGF-β1 mRNA expression despite high blood glucose levels. To elucidate the mechanisms of the renal effects of lovastatin, rat mesangial cells were cultured under control (5.5 mM) or high (30 mM) glucose with lovastatin alone, mevalonate alone, or with both. Under high glucose, TGF-β1 and fibronectin mRNA and proteins were upregulated. These high glucose-induced changes were suppressed by lovastatin (10 μM) and nearly completely restored by mevalonate (100 μM). These results suggest that lovastatin has a direct cellular effect independent of a cholesterol-lowering effect and delays the onset and progression of diabetic nephropathy, at least in part, through suppression of glomerular expression of TGF-β1.

scholarly journals Transcriptional Suppression of Diabetic Nephropathy with Novel Gene Silencer Pyrrole-Imidazole Polyamides Preventing USF1 Binding to the TGF-β1 Promoter

2021 ◽  
Vol 22 (9) ◽  
pp. 4741
Author(s):  
Makiyo Okamura ◽  
Noboru Fukuda ◽  
Shu Horikoshi ◽  
Hiroki Kobayashi ◽  
Akiko Tsunemi ◽  
...  
Keyword(s):  
Diabetic Nephropathy ◽  
High Glucose ◽  
Transforming Growth Factor ◽  
Mesangial Cells ◽  
Diabetic Rats ◽  
Glomerular Injury ◽  
Upstream Stimulatory Factor ◽  
Injury Score ◽  
Upstream Stimulatory Factor 1 ◽  
Tgf Β1

Upstream stimulatory factor 1 (USF1) is a transcription factor that is increased in high-glucose conditions and activates the transforming growth factor (TGF)-β1 promoter. We examined the effects of synthetic pyrrole-imidazole (PI) polyamides in preventing USF1 binding on the TGF-β1 promoter in Wistar rats in which diabetic nephropathy was established by intravenous administration of streptozotocin (STZ). High glucose induced nuclear localization of USF1 in cultured mesangial cells (MCs). In MCs with high glucose, USF1 PI polyamide significantly inhibited increases in promoter activity of TGF-β1 and expression of TGF-β1 mRNA and protein, whereas it significantly decreased the expression of osteopontin and increased that of h-caldesmon mRNA. We also examined the effects of USF1 PI polyamide on diabetic nephropathy. Intraperitoneal injection of USF1 PI polyamide significantly suppressed urinary albumin excretion and decreased serum urea nitrogen in the STZ-diabetic rats. USF1 PI polyamide significantly decreased the glomerular injury score and tubular injury score in the STZ-diabetic rats. It also suppressed the immunostaining of TGF-β1 in the glomerulus and proximal tubules and significantly decreased the expression of TGF-β1 protein from kidney in these rats. These findings indicate that synthetic USF1 PI polyamide could potentially be a practical medicine for diabetic nephropathy.

scholarly journals Protective effect of syringaresinol on rats with diabetic nephropathy via regulation of Nrf2/HO-1 and TGF- β1/Smads pathways

2022 ◽  
Vol 20 (2) ◽  
pp. 275-280
Author(s):  
Lei Ji ◽  
Xue Zhong ◽  
Xingxing Xia ◽  
Wei Yu ◽  
Yuping Qin
Keyword(s):  
Diabetic Nephropathy ◽  
Blood Glucose ◽  
Protective Effect ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Enzyme Linked Immunosorbent Assay ◽  
Heme Oxygenase 1 ◽  
Related Factor ◽  
Pathological Changes ◽  
Tgf Β1

Purpose: To investigate the protective role of syringaresinol in a rat model of diabetic nephropathy (DN). Methods: Streptozotocin was injected intraperitoneally into rats to establish the diabetic model. Streptozotocin-induced rats were orally administered syringaresinol, and pathological changes in kidneys were assessed using hematoxylin and eosin staining. Enzyme-linked immunosorbent assay (ELISA) was used to determine kidney injury indicators, 24-h urine proteins, blood urea nitrogen (BUN), and serum creatinine (SCR). Blood glucose was measured using a blood glucose meter, while levels of malonaldehyde (MDA), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-PX) in kidney were also measured using ELISA. Results: Pathological changes in the kidneys were observed in rats post-streptozotocin treatment. Administration of syringaresinol reduced the lesion degree, with improved pathological morphology in kidney. Syringaresinol administration significantly attenuated streptozotocin-increased levels of BUN, SCR, 24-h urine protein, and blood glucose (p < 0.01). Streptozotocin-induced oxidative stress, shown by enhanced MDA level and reduced levels of SOD, CAT, and GSH-PX, was reversed in rat kidneys following syringaresinol administration. However, the expression levels of nuclear factor erythropoietin- 2-related factor 2 (Nrf2) and heme oxygenase 1 (HO-1) proteins decreased, while transforming growth factor-beta 1 (TGF-β1) and signal transducer and transcriptional modulator (Smad) 2/3/7 proteins increased in rats post-streptozotocin treatment. Syringaresinol administration reversed the effects of streptozotocin on protein expression of Nrf2, HO-1, TGF-β1, and Smad 2/3/7. Conclusion: Syringaresinol exerted a protective effect against DN through activation of Nrf2 and inactivation of TGF-β1/Smad pathways. Thus, the compound can potentially be developed for management of diabetic nephropathy.

Calcineurin is activated in diabetes and is required for glomerular hypertrophy and ECM accumulation

2003 ◽  
Vol 284 (1) ◽  
pp. F144-F154 ◽  
Author(s):  
Jennifer L. Gooch ◽  
Jeffrey L. Barnes ◽  
Sergio Garcia ◽  
Hanna E. Abboud
Keyword(s):  
Diabetic Nephropathy ◽  
Transforming Growth Factor ◽  
Mesangial Cells ◽  
Transforming Growth Factor Β ◽  
Rapid Onset ◽  
Diabetic Rats ◽  
Glomerular Hypertrophy ◽  
Renal Hypertrophy ◽  
Calcineurin Phosphatase ◽  
Calcineurin Inhibition

Diabetic nephropathy is characterized by the rapid onset of hypertrophy and ECM expansion. Previously, we showed that calcineurin phosphatase is required for hypertrophy and ECM synthesis in cultured mesangial cells. Therefore, we examined the effect of calcineurin inhibition on renal hypertrophy and ECM accumulation in streptozotocin-induced diabetic rats. After 2 wk of diabetes, calcineurin protein was increased in whole cortex and glomeruli in conjunction with increased phosphatase activity. Daily administration of cyclosporin A blocked accumulation of both calcineurin protein and calcineurin activity. Also associated with calcineurin upregulation was nuclear localization of the calcineurin substrate NFATc1. Inhibition of calcineurin reduced whole kidney hypertrophy and abolished glomerular hypertrophy in diabetic rats. Furthermore, calcineurin inhibition substantially reduced ECM accumulation in diabetic glomeruli but not in cortical tissue, suggesting a differential effect of calcineurin inhibition in glomerular vs. extraglomerular tissue. Corresponding increases in fibronectin mRNA and transforming growth factor-β mRNA were observed in tubulointerstitium but not in glomeruli. In summary, calcineurin plays an important role in glomerular hypertrophy and ECM accumulation in diabetic nephropathy.

scholarly journals Involvement of p300/CBP and epigenetic histone acetylation in TGF-β1-mediated gene transcription in mesangial cells

2013 ◽  
Vol 304 (5) ◽  
pp. F601-F613 ◽  
Author(s):  
Hang Yuan ◽  
Marpadga A. Reddy ◽  
Guangdong Sun ◽  
Linda Lanting ◽  
Mei Wang ◽  
...  
Keyword(s):  
Diabetic Nephropathy ◽  
Histone Acetylation ◽  
Transforming Growth Factor ◽  
Mesangial Cells ◽  
Mrna Levels ◽  
Creb Binding Protein ◽  
Diabetic Mice ◽  
Plasminogen Activator Inhibitor 1 ◽  
Tgf Β1 ◽  
Pai 1

Transforming growth factor-β1 (TGF-β1)-induced expression of plasminogen activator inhibitor-1 (PAI-1) and p21 in renal mesangial cells (MCs) plays a major role in glomerulosclerosis and hypertrophy, key events in the pathogenesis of diabetic nephropathy. However, the involvement of histone acetyl transferases (HATs) and histone deacetylases (HDACs) that regulate epigenetic histone lysine acetylation, and their interaction with TGF-β1-responsive transcription factors, are not clear. We evaluated the roles of histone acetylation, specific HATs, and HDACs in TGF-β1-induced gene expression in rat mesangial cells (RMCs) and in glomeruli from diabetic mice. Overexpression of HATs CREB binding protein (CBP) or p300, but not p300/CBP-activating factor, significantly enhanced TGF-β1-induced PAI-1 and p21 mRNA levels as well as transactivation of their promoters in RMCs. Conversely, they were significantly attenuated by HAT domain mutants of CBP and p300 or overexpression of HDAC-1 and HDAC-5. Chromatin immunoprecipitation assays showed that TGF-β1 treatment led to a time-dependent enrichment of histone H3-lysine9/14-acetylation (H3K9/14Ac) and p300/CBP occupancies around Smad and Sp1 binding sites at the PAI-1 and p21 promoters. TGF-β1 also enhanced the interaction of p300 with Smad2/3 and Sp1 and increased Smad2/3 acetylation. High glucose-treated RMCs exhibited increased PAI-1 and p21 levels, and promoter H3K9/14Ac, which were blocked by TGF-β1 antibodies. Furthermore, increased PAI-1 and p21 expression was associated with elevated promoter H3K9/14Ac levels in glomeruli from diabetic mice. Thus TGF-β1-induced PAI-1 and p21 expression involves interaction of p300/CBP with Smads and Sp1, and increased promoter access via p300/CBP-induced H3K9/14Ac. This in turn can augment glomerular dysfunction linked to diabetic nephropathy.

High glucose-induced RhoA activation requires caveolae and PKCβ1-mediated ROS generation

2012 ◽  
Vol 302 (1) ◽  
pp. F159-F172 ◽  
Author(s):  
Y. Zhang ◽  
F. Peng ◽  
B. Gao ◽  
A. J. Ingram ◽  
J. C. Krepinsky
Keyword(s):  
Diabetic Nephropathy ◽  
Nadph Oxidase ◽  
High Glucose ◽  
Transforming Growth Factor ◽  
Mesangial Cells ◽  
Ros Generation ◽  
Caveolin 1 ◽  
Rhoa Activation ◽  
Rhoa Signaling ◽  
Tgf Β1

Glomerular matrix accumulation is a hallmark of diabetic nephropathy. We previously showed that RhoA activation by high glucose in mesangial cells (MC) leads to matrix upregulation (Peng F, Wu D, Gao B, Ingram AJ, Zhang B, Chorneyko K, McKenzie R, Krepinsky JC. Diabetes 57: 1683–1692, 2008). Here, we study the mechanism whereby RhoA is activated. In primary rat MC, RhoA activation required glucose entry and metabolism. Broad PKC inhibitors (PMA, bisindolylmaleimide, Gö6976), as well as specific PKCβ blockade with an inhibitor and small interfering RNA (siRNA), prevented RhoA activation by glucose. PKCβ inhibition also abrogated reactive oxygen species (ROS) generation by glucose. The ROS scavenger N-acetylcysteine (NAC) or NADPH oxidase inhibitors apocynin and DPI prevented glucose-induced RhoA activation. RhoA and some PKC isoforms localize to caveolae. Chemical disruption of these microdomains prevented RhoA and PKCβ1 activation by glucose. In caveolin-1 knockout cells, glucose did not induce RhoA and PKCβ1 activation; these responses were rescued by caveolin-1 reexpression. Furthermore, glucose-induced ROS generation was significantly attenuated by chemical disruption of caveolae and in knockout cells. Downstream of RhoA signaling, activator protein-1 (AP-1) activation was also inhibited by disrupting caveolae, was absent in caveolin-1 knockout MC and rescued by caveolin-1 reexpression. Finally, transforming growth factor (TGF)-β1 upregulation, mediated by AP-1, was prevented by RhoA signaling inhibition and by disruption or absence of caveolae. In conclusion, RhoA activation by glucose is dependent on PKCβ1-induced ROS generation, most likely through NADPH oxidase. The activation of PKCβ1 and its downstream effects, including upregulation of TGF-β1, requires caveolae. These microdomains are thus important mediators of the profibrogenic process associated with diabetic nephropathy.

scholarly journals Contribution of TGF-β1 and Effects of Gene Silencer Pyrrole-Imidazole Polyamides Targeting TGF-β1 in Diabetic Nephropathy

Molecules ◽  
2020 ◽  
Vol 25 (4) ◽  
pp. 950 ◽  
Author(s):  
Shu Horikoshi ◽  
Noboru Fukuda ◽  
Akiko Tsunemi ◽  
Makiyo Okamura ◽  
Masari Otsuki ◽  
...  
Keyword(s):  
Diabetic Nephropathy ◽  
Target Genes ◽  
Mesangial Cells ◽  
Diabetic Rats ◽  
Histological Evaluation ◽  
Renal Diseases ◽  
Podocyte Injury ◽  
Tgf Β1

TGF-β1 has been known to induce diabetic nephropathy with renal fibrosis and glomerulosclerosis. DNA-recognized peptide compound pyrrole-imidazole (PI) polyamides as novel biomedicines can strongly bind promoter lesions of target genes to inhibit its transcription. We have developed PI polyamide targeting TGF-β1 for progressive renal diseases. In the present study, we evaluated the contribution of TGF-β1 in the pathogenesis of diabetic nephropathy, and examined the effects of PI polyamide targeting TGF-β1 on the progression of diabetic nephropathy in rats. For in vitro experiments, rat renal mesangial cells were incubated with a high (25 mM) glucose concentration. Diabetic nephropathy was established in vivo in eight-week-old Wistar rats by intravenously administering 60 mg/kg streptozotocin (STZ). We examined the effects of PI polyamide targeting TGF-β1 on phenotype and the growth of mesangial cells, in vitro, and the pathogenesis of diabetic nephropathy in vivo. High glucose significantly increased expression of TGF-β1 mRNA, changed the phenotype to synthetic, and increased growth of mesangial cells. STZ diabetic rats showed increases in urinary excretions of protein and albumin, glomerular and interstitial degenerations, and podocyte injury. Treatment with PI polyamide targeting TGF-β1 twice weekly for three months improved the glomerular and interstitial degenerations by histological evaluation. Treatment with PI polyamide improved podocyte injury by electron microscopy evaluation. These findings suggest that TGF-β1 may be a pivotal factor in the progression of diabetic nephropathy, and PI polyamide targeting TGF-β1 as a practical medicine may improve nephropathy.

scholarly journals Effect of Oral carnosine supplementation on urinary TGF-β in diabetic nephropathy: a randomized controlled trial

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Narongrit Siriwattanasit ◽  
Bancha Satirapoj ◽  
Ouppatham Supasyndh
Keyword(s):  
Renal Function ◽  
Diabetic Nephropathy ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Controlled Trial ◽  
Oral Supplementation ◽  
Urine Albumin ◽  
Baseline Values ◽  
Growth Factor Beta ◽  
Baseline Characteristics

Abstract Background Activation of the transforming growth factor beta (TGF-β) pathway is a significant contributor to the pathogenesis of diabetic nephropathy. Carnosine is a dipeptide that can inhibit TGF-β synthesis. We tested the hypothesis that carnosine supplement added to standard therapy will result in reduced urinary TGF-β levels among patients with diabetic nephropathy. Methods We randomly assigned 40 patients with diabetic nephropathy and albuminuria 30–299 mg/day to treatment with carnosine (2 g/day) or placebo for 12 weeks. Urinary TGF-β level was determined using ELISA, urine albumin was ascertained by immunonephelometric assay, and renal function and metabolic profiles were determined at baseline and during 12 weeks of active treatment. Primary outcome was decrease in urinary levels of TGF-β. Results The 2 groups were comparable for baseline characteristics, blood pressure, urine albumin, urine TGF-β and renal function measurements. Urinary TGF-β significantly decreased with carnosine supplement (− 17.8% of the baseline values), whereas it tended to increase with placebo (+ 16.9% of the baseline values) (between-group difference P < 0.05). However, blood urea nitrogen, serum creatinine, glomerular filtration rate and other biochemical parameters remained unchanged during the study period including urinary albuminuria. Both groups were well tolerated with no serious side-effects. Conclusions These data indicated an additional renoprotective effect of oral supplementation with carnosine to decrease urinary TGF-β level that serves as a marker of renal injury in diabetic nephropathy. Trial registration Thai Clinical Trials, TCTR20200724002. Retrospectively Registered 24 July 2020.

Sequoyitol ameliorates diabetic nephropathy in diabetic rats induced with a high-fat diet and a low dose of streptozotocin

2014 ◽  
Vol 92 (5) ◽  
pp. 405-417 ◽  
Author(s):  
Xian-Wei Li ◽  
Yan Liu ◽  
Wei Hao ◽  
Jie-Ren Yang
Keyword(s):  
Diabetic Nephropathy ◽  
Blood Glucose ◽  
High Fat Diet ◽  
Low Dose ◽  
Serum Insulin ◽  
Fasting Blood Glucose ◽  
Diabetic Rats ◽  
High Fat

Sequoyitol decreases blood glucose, improves glucose intolerance, and enhances insulin signaling in ob/ob mice. The aim of this study was to investigate the effects of sequoyitol on diabetic nephropathy in rats with type 2 diabetes mellitus and the mechanism of action. Diabetic rats, induced with a high-fat diet and a low dose of streptozotocin, and were administered sequoyitol (12.5, 25.0, and 50.0 mg·(kg body mass)−1·d−1) for 6 weeks. The levels of fasting blood glucose (FBG), serum insulin, blood urea nitrogen (BUN), and serum creatinine (SCr) were measured. The expression levels of p22phox, p47phox, NF-κB, and TGF-β1 were measured using immunohistochemisty, real-time PCR, and (or) Western blot. The total antioxidative capacity (T-AOC), as well as the levels of malondialdehyde (MDA) and reactive oxygen species (ROS) were also determined. The results showed that sequoyitol significantly decreased FBG, BUN, and SCr levels, and increased the insulin levels in diabetic rats. The level of T-AOC was significantly increased, while ROS and MDA levels and the expression of p22phox, p47phox, NF-κB, and TGF-β1 were decreased with sequoyitol treatment both in vivo and in vitro. These results suggested that sequoyitol ameliorates the progression of diabetic nephropathy in rats, as induced by a high-fat diet and a low dose of streptozotocin, through its glucose-lowering effects, antioxidant activity, and regulation of TGF-β1 expression.

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