stilbenes and Diabetic-Nephropathies

Diabetic nephropathy (DN) is manifested as increased urinary protein level, decreased glomerular filtration rate, and final renal dysfunction. DN is the leading cause of end-stage renal disease worldwide and causes a huge societal healthcare burden. Since satisfied treatments are still limited, exploring new strategies for the treatment of this disease is urgently needed. Oxidative stress takes part in the initiation and development of DN. In addition, nuclear factor erythroid 2-related factor 2 (Nrf2) plays a key role in the cellular response to oxidative stress. Thus, activation of Nrf2 seems to be a new choice for the treatment of DN. In current review, we discussed and summarized the therapeutic effects of Nrf2 activation on DN from both basic and clinical studies.

Topics: Animals; Anticarcinogenic Agents; Antioxidant Response Elements; Antioxidants; Curcumin; Cysteine Proteinase Inhibitors; Diabetic Nephropathies; Enzyme Inhibitors; Humans; Isothiocyanates; Leupeptins; Molecular Targeted Therapy; NF-E2-Related Factor 2; Oxidative Stress; Resveratrol; Rutin; Signal Transduction; Stilbenes; Sulfoxides; Trace Elements; Zinc

Diabetic nephropathy (DN) is a severe microvascular complication of diabetes mellitus and a primary reason for end-stage renal disease (ESRD). Isorhapontigenin (ISO), a natural derivative of stilbene, has significant anti-inflammatory and antioxidant effects. Nevertheless, its impact on DN remains elusive.. Human vascular endothelial cells (HUVECs) and podocytes were damaged by high glucose (HG). Cell viability and apoptosis were testified by the cell counting kit-8 (CCK-8) assay and flow cytometry, respectively. The mRNA profiles of antioxidant factors HO-1, NQO1, and Prx1 were monitored by real-time quantitative polymerase chain reaction (RT-qPCR). Western blotting (WB) was implemented to verify the expression of apoptosis-related proteins (Bax, Bad, and Bcl-XL), antioxidant factors (HO-1, NQO1, and Prx1), autophagy-related proteins (Beclin-1, ATG5, p62), podocalyxin (podocin, nephrin, and synaptopodin) and the AMPK/Nrf2 pathway. The levels of oxidative stress-related markers MDA, SOD and CAT were assessed with the corresponding kits. Compound C (CC), an inhibitor of AMPK, was deployed to probe the effects of modulating the AMPK/Nrf2 pathway on ISO in oxidative stress and autophagy in HUVECs and podocytes. Streptozotocin (STZ) was injected intraperitoneally into mice to establish an animal model of diabetes mellitus and to clarify the impact of ISO on the renal parameters such as serum creatinine, urea nitrogen and urinary protein in diabetic mice.. ISO notably facilitated cell proliferation, impeded apoptosis, elevated the expression of antioxidant-related factors, alleviated HG-induced oxidative stress and activated autophagy in HUVECs and podocytes. ISO activated the AMPK/Nrf2 pathway. Attenuating AMPK diminished the protective effect of ISO on HUVECs and podocytes, curbed cell proliferation, intensified apoptosis and oxidative stress, and dampened autophagy. In-vivo experiments also displayed that ISO reduced histopathological damage, lowered serum creatinine, urea nitrogen and urinary ACR levels, and eased kidney damage in DN mice.. ISO attenuates HG-induced oxidative stress and activates autophagy by motivating the AMPK/Nrf2 pathway, exerting a protective effect on HUVECs and podocytes and reducing renal injury in DN mice.

Topics: AMP-Activated Protein Kinases; Animals; Antioxidants; Apoptosis; Autophagy; Creatinine; Diabetes Mellitus, Experimental; Diabetic Nephropathies; Endothelial Cells; Glucose; Humans; Mice; NF-E2-Related Factor 2; Oxidative Stress; Podocytes; Signal Transduction; Stilbenes; Urea

Diabetic kidney disease is a major cause of global end-stage renal diseases. Ectopic lipid deposition in the renal tissues of diabetic kidney disease is one major factor leading to renal fibrosis and chronic kidney disease. Pterostilbene has been reported to display lipid-lowing activity and participate in many kidney diseases. However, the influence of pterostilbene on the ectopic lipid deposition is unclear. We intend to explore the influence of pterostilbene on the ectopic lipid deposition in the kidneys of mice induced by high fat.. A high-fat diet-induced diabetic mouse model was established to detect the alleviative effect of pterostilbene on the ectopic lipid deposition in the kidneys of diabetic mice. A biochemical analysis was performed to examine the levels of urine albumin, urine creatinine, serum creatinine, and blood urea nitrogen in mice after pterostilbene treatment. Histological analysis was conducted to detect the degree of renal injury and fibrosis. Oil red O staining and immunohistochemical staining were carried out to evaluate lipid droplets and the expression of adipose differentiation-related protein in renal tissues of the mice treated by pterostilbene. The protein levels were assessed by Western blotting.. Pterostilbene inhibits the expression of the TGF-β1 and p-smad3 and suppresses the protein levels of SREBP-1 and FAS, and it ultimately reduces the ectopic lipid deposition, alleviates the renal tubular damage and renal fibrosis in the kidneys of diabetic mice induced by high fat, and improves kidney function.. Pterostilbene alleviates renal fibrosis and ectopic lipid deposition in the kidneys of diabetic mice induced by high-fat diet by inhibiting the TGF-β1/smad3 signaling.

Topics: Animals; Diabetes Mellitus, Experimental; Diabetic Nephropathies; Diet, High-Fat; Fibrosis; Kidney; Lipids; Mice; Resveratrol; Stilbenes; Transforming Growth Factor beta1

To investigate the effect of polydatin on glucose transporter, blood glucose homeostasis and renal injury in streptozotocin (STZ)-induced diabetic rats. The in vitro inhibitory effect of polydatin on sodium-glucose cotransporter-1 (SGLT1) and 2 (SGLT2) was determined using HEK293 cells. The inhibitory effect of polydatin on GLUT1 and GLUT4 was evaluated using 3T3-L1 adipocytes. Streptozotocin-induced diabetic rats were used for this study. Fasting blood glucose (FBG), glycosylated hemoglobin (HbA1c), urea nitrogen, serum creatinine and urinary protein were determined using biochemical analyzer. Histopathological examination was performed on renal tissue. Serum levels of interleukin 1β (IL-1β), tumor necrosis factor α (TNF-α), monocyte chemoattractant protein 1 (MCP-1) and C-reactive protein (CRP) were also determined. Polydatin significantly inhibited SGLT1/2 and exhibited high selectivity for both GLUT1 and GLUT4. It significantly and dose-dependently decreased hyperglycemia, enhanced urine glucose excretion in the diabetic rats. The polydatin treatment significantly ameliorated symptoms of DN such as polyuria, polydipsia and hyperphagia. The hypoglycemic effect of polydatin was maintained throughout the treatment period. In addition,the levels of IL-1β, TNF-α, MCP-1 and CRP were significantly reduced in treated group. Treatment with polydatin significantly ameliorated most of the structural and morphological changes induced by STZ. Moreover, the levels of urinary protein, serum creatinine and urea nitrogen were significantly reduced after treatment with polydatin.  As a potential dual inhibitor of SGLT1/2, polydatin has high selectivity for GLUT1 and GLUT4. Its long-term administration delays the development of DN, protects renal function and ameliorates renal tissue injury.

Topics: 3T3-L1 Cells; Animals; Blood Glucose; Diabetes Mellitus, Experimental; Diabetic Nephropathies; Glucose Transporter Type 1; Glucose Transporter Type 4; Glucosides; HEK293 Cells; Humans; Hyperglycemia; Inflammation; Mice; Sodium-Glucose Transporter 1; Sodium-Glucose Transporter 2; Stilbenes

Our study investigated the therapeutic role and potential mechanisms of pterostilbene (PS) in diabetic nephropathy (DN) rats.. DN models were established by high-fat diet after streptozotocin injection. A total of 50 Sprague-Dawley rats were randomly divided into control, DN, PS-treated groups (PS-H, PS-M, PS-L). PS was administered to rats by gavage for 8 weeks at 3 different doses (25, 10, and 5 mg/kg/day). The levels of oxidative stress activity (superoxide dismutase [SOD], malondialdehyde [MDA], glutathione peroxidase [GSH-PX]) and inflammatory factors (tumor necrosis factor [TNF]-α, interleukin (IL)-6, IL-1β, monocyte chemoattractant factor [MCP]-1) were detected by -ELISA. TGF-β, Smad1, and fibronectin (FN) were measured through immunohistochemistry. The relative expressions of phospho-IκBα/IκBα, phospho-IκB kinases (IKK)β/IKKβ, phospho-nuclear factor-κB (NF-κB) p65/NF-κB p65 were detected by western blot.. Compared with DN group, the levels of TNF-α, IL-6, IL-1β, and MCP-1 were decreased in the PS-H group (p < 0.05). Meanwhile, the levels of SOD, MDA, GSH-PX improved in kidney and serum in PS-H groups (p< 0.05). PS also significantly decreased the level of phospho-NF-κB p65 and increased the levels of phospho- IKKβ and phospho-Iκ-Bα (p < 0.05). The results showed that PS treatment decreased TGF-β, Smad1, and FN expressions.. PS had potential therapeutic effects on DN, which may be related to the regulation of NF-κB pathway.

Topics: Animals; Diabetes Mellitus, Experimental; Diabetic Nephropathies; Diet, High-Fat; Drug Evaluation, Preclinical; Fibronectins; Humans; Kidney; Male; NF-kappa B; Oxidative Stress; Rats; Rats, Sprague-Dawley; Signal Transduction; Smad1 Protein; Stilbenes; Streptozocin; Transforming Growth Factor beta; Treatment Outcome

Podocyte injury and loss contribute to the progression of glomerular diseases, including diabetic kidney disease. We previously found that the glomerular expression of Sirtuin-1 (SIRT1) is reduced in human diabetic glomeruli and that the podocyte-specific loss of SIRT1 aggravated albuminuria and worsened kidney disease progression in diabetic mice. SIRT1 encodes an NAD-dependent deacetylase that modifies the activity of key transcriptional regulators affected in diabetic kidneys, including NF-κB, STAT3, p53, FOXO4, and PGC1-α. However, whether the increased glomerular SIRT1 activity is sufficient to ameliorate the pathogenesis of diabetic kidney disease has not been explored. We addressed this by inducible podocyte-specific SIRT1 overexpression in diabetic OVE26 mice. The induction of SIRT1 overexpression in podocytes for six weeks in OVE26 mice with established albuminuria attenuated the progression of diabetic glomerulopathy. To further validate the therapeutic potential of increased SIRT1 activity against diabetic kidney disease, we developed a new, potent and selective SIRT1 agonist, BF175. In cultured podocytes BF175 increased SIRT1-mediated activation of PGC1-α and protected against high glucose-mediated mitochondrial injury. In vivo, administration of BF175 for six weeks in OVE26 mice resulted in a marked reduction in albuminuria and in glomerular injury in a manner similar to podocyte-specific SIRT1 overexpression. Both podocyte-specific SIRT1 overexpression and BT175 treatment attenuated diabetes-induced podocyte loss and reduced oxidative stress in glomeruli of OVE26 mice. Thus, increased SIRT1 activity protects against diabetes-induced podocyte injury and effectively mitigates the progression of diabetic kidney disease.

Topics: Albuminuria; Animals; Blood Glucose; Boronic Acids; Cell Line; Diabetes Mellitus, Type 1; Diabetic Nephropathies; Disease Models, Animal; Enzyme Induction; Mice, Transgenic; Mitochondria; Oxidative Stress; Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; Podocytes; Signal Transduction; Sirtuin 1; Stilbenes

Podocyte apoptosis coincides with albuminuria onset and precedes podocytopenia in diabetic nephropathy. However, there is a lack of effective therapeutic drugs to protect podocytes from apoptosis. Here, we demonstrated that resveratrol relieved a series of indicators of diabetic nephropathy and attenuated apoptosis of podocytes in db/db diabetic model mice. In addition, resveratrol induced autophagy in both db/db mice and human podocytes. Furthermore, inhibition of autophagy by 3-methyladenine (3-MA) and autophagy gene 5 (Atg5) short hairpin RNA (shRNA) reversed the protective effects of resveratrol on podocytes. Finally, we found that resveratrol might regulate autophagy and apoptosis in db/db mice and podocytes through the suppression of microRNA-383-5p (miR-383-5p). Together, our results indicate that resveratrol effectively attenuates high glucose-induced apoptosis via the activation of autophagy in db/db mice and podocytes, which involves miR-383-5p. Thus, this study reveals a new possible strategy to treat diabetic nephropathy.

Topics: Albuminuria; Animals; Apoptosis; Autophagy; Diabetic Nephropathies; Disease Models, Animal; Mice; Mice, Inbred C57BL; Podocytes; Protective Agents; Resveratrol; RNA, Small Interfering; Stilbenes

Polydatin (PD), a resveratrol glycoside, has been shown to protect renal function in diabetic nephropathy (DN), but the underlying molecular mechanism remains unclear. This study demonstrates that PD stabilize the mitochondrial morphology and attenuate mitochondrial malfunction in both KKAy mice and in hyperglycemia (HG)-induced MPC5 cells. We use Western blot analysis to demonstrate that PD reversed podocyte apoptosis induced by HG via suppressing dynamin-related protein 1 (Drp1). This effect may depend on the ability of PD to inhibit the generation of cellular reactive oxygen species (ROS). In conclusion, we demonstrate that PD may be therapeutically useful in DN, and that, podocyte apoptosis induced by HG can be reversed by PD through suppressing Drp1 expression.

Topics: Animals; Apoptosis; Blood Glucose; Cell Line; Cytoprotection; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Disease Models, Animal; Down-Regulation; Dynamins; Glucosides; Mice, Inbred C57BL; Mitochondria; Mitochondrial Dynamics; Podocytes; Reactive Oxygen Species; RNA Interference; Signal Transduction; Stilbenes; Transfection

Diabetic nephropathy is one of the major microvascular complications of diabetes mellitus which ultimately gives rise to cardiovascular diseases. Prolonged hyperglycaemia and chronic renal inflammation are the two key players in the development and progression of diabetic nephropathy. Nuclear factor kB (NF-kB)-mediated inflammatory cascade is a strong contributor to the renovascular inflammation in diabetic nephropathy. Here, we studied the effects of piceatannol, a potent NF-kB inhibitor, on various oxidative stress markers and NF-kB dependent diabetic renoinflammatory cascades in rat induced by alloxan (ALX). Experimental diabetes was induced in male Wistar rats by a single intraperitoneal dose, 150 mg/kg body-weight (b.w.) of ALX. Diabetic rats were treated with Piceatannol (PCTNL) at a dose of 30 and 50 mg/kg b.w. After 14 days of oral treatment, PCTNL significantly restored blood sugar level, glomerular filtration rate, serum markers and plasma lipids. PCTNL administration also reversed the declined activity of cellular antioxidant machineries namely superoxide dismutase and glutathione and the elevated levels of malondialdehyde and nitric oxide. Moreover, piceatannol-treated groups showed marked inhibition of renal pro-inflammatory cytokines and NF-kB p65/p50 binding to DNA. Renal histopathological investigations also supported its ameliorative effects against diabetic kidney damage. Importantly, effects were more prominent at a dose of 50 mg/kg, and in terms of body-weight gain, PCTNL failed to effect significantly. However, overall findings clearly demonstrated that PCTNL provides remarkable renoprotection in diabetes by abrogating oxidative stress and NF-kB activation - and might be helpful in early stage of diabetic nephropathy.

Topics: Alloxan; Animals; Antioxidants; Diabetes Mellitus, Experimental; Diabetic Nephropathies; Dose-Response Relationship, Drug; Glomerular Filtration Rate; Glutathione; Inflammation; Kidney; Male; Malondialdehyde; NF-kappa B; Oxidative Stress; Rats; Rats, Wistar; Stilbenes; Superoxide Dismutase

Oxidative stress plays an important role in the development and progression of diabetic nephropathy (DN). We aimed to investigate if resveratrol (RSV) could ameliorate hyperglycemia-induced oxidative stress in renal tubules via modulating the SIRT1/FOXO3a pathway.. The effects of RSV on diabetes rats were assessed by periodic acid-Schiff, Masson staining, immunohistochemistry, and western blot analyses. Additionally, oxidative indicators (such as catalase, superoxide dismutase, reactive oxygen species, and malondialdehyde), the deacetylase activity of SIRT1 and protein expressions of SIRT1, FOXO3a, and acetylated-FOXO3a were measured. These indicators were similarly evaluated in an in vitro study. Furthermore, the silencing of SIRT1 was used to confirm its role in the resistance to oxidative stress and the relationship between SIRT1 and FOXO3a in vitro.. After 16weeks of RSV treatment, the renal function and glomerulosclerosis of rats with DN was dramatically ameliorated. RSV treatment increased SIRT1 deacetylase activity, subsequently decreasing the expression of acetylated-FOXO3a and inhibiting the oxidative stress caused by hyperglycemia both in vivo and in vitro. The silencing of SIRT1 in HK-2 cells aggravated the high glucose-induced oxidative stress and overexpression of acetylated-FOXO3a; RSV treatment failed to protect against these effects.. RSV modulates the SIRT1/FOXO3a pathway by increasing SIRT1 deacetylase activity, subsequently ameliorating hyperglycemia-induced renal tubular oxidative stress damage. This mechanism provides the basis for a new approach to developing an effective DN treatment, which is of great clinical significance for reducing the morbidity and mortality associated with DN.

Topics: Animals; Catalase; Cytoprotection; Diabetic Nephropathies; Forkhead Box Protein O3; Hyperglycemia; Kidney Tubules; Male; Oxidative Stress; Rats; Rats, Wistar; Reactive Oxygen Species; Resveratrol; Signal Transduction; Sirtuin 1; Stilbenes; Superoxide Dismutase

Our previous study indicated that Casein kinase 2 interacting protein-1 (CKIP-1) could promote the activation of the nuclear factor E2-related factor 2 (Nrf2)/ antioxidant response element (ARE) pathway, playing a significant role in inhibiting the fibrosis of diabetic nephropathy (DN). Polydatin (PD) has been shown to possess strong resistance effects on renal fibrosis which is closely related to activating the Nrf2/ARE pathway, too. Whereas, whether PD could resist DN through regulating CKIP-1 and consequently promoting the activation of Nrf2-ARE pathway needs further investigation. Here, we found that PD significantly reversed the down-regulation of CKIP-1 and attenuated fibronectin (FN) and intercellular cell adhesion molecule-1 (ICAM-1) in glomerular mesangial cells (GMCs) exposed to high glucose (HG). Moreover, PD could decrease Keap1 expression and promote the nuclear content, ARE-binding ability, and transcriptional activity of Nrf2. The activation of Nrf2-ARE pathway by PD eventually led to the quenching of hydrogen peroxide (H

Topics: Animals; Antioxidants; Carboxylic Ester Hydrolases; Carrier Proteins; Diabetic Nephropathies; Fibronectins; Gene Expression Regulation; Glucose; Glucosides; Humans; Hydrogen Peroxide; Intercellular Adhesion Molecule-1; Kelch-Like ECH-Associated Protein 1; Mesangial Cells; Mice; Mice, Inbred NOD; NF-E2-Related Factor 2; Signal Transduction; Stilbenes; Superoxides

Type 2 diabetic nephropathy (DN) is a serious end-stage kidney disease worldwide. Multiple studies demonstrate that resveratrol (RSV) has a beneficial effect on DN. However, whether RSV-induced improvement in kidney function in diabetes is due to the regulation of autophagy remains unclear. Here, we investigated the mechanisms underlying RSV-mediated protection against DN in diabetic rats, with a special focus on the role of NAD-dependent deacetylase sirtuin 1 (Sirt1) in regulating autophagy. We found that long-term RSV treatment in rats promoted Sirt1 expression and improved related metabolic levels in the diabetic kidney. Our study showed that, in cultured NRK-52E cells, Sirt1 knockdown inhibited the autophagy levels of proteins Atg7, Atg5, and LC3 and impaired the RSV amelioration of dysfunctional autophagy under hypoxic condition. Furthermore, exposed to 1% O2 over time induced autophagy dysfunction and apoptosis in NRK-52E cells, which could be improved by RSV treatment. Our data highlight the role of the Sirt1-mediated pathway in the effects of RSV on autophagy in vivo and in vitro, suggesting RSV could be a potential new therapy for type 2 DN.

Topics: Animals; Antioxidants; Autophagy; Blotting, Western; Cell Hypoxia; Cell Line; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Enzyme-Linked Immunosorbent Assay; Gene Knockdown Techniques; Male; Rats; Rats, Sprague-Dawley; Resveratrol; Reverse Transcriptase Polymerase Chain Reaction; Sirtuin 1; Stilbenes

Adiponectin has multiple functions including insulin sensitization, anti-inflammation and antiatherogenesis in various organs. Adiponectin activates 5'-adenosine monophosphate-activated protein kinase (AMPK) and peroxisome proliferator-activated receptor (PPAR)α via the adiponectin receptor (AdipoR) 1 and 2, which are critical for regulating lipids and glucose homeostasis and for controlling oxidative stress. We investigated whether resveratrol can inhibit renal damage in type 2 diabetic db/db mice and the underlying mechanisms of its effects.. Four groups of male C57 BLKS/J db/m and db/db mice and human glomerular endothelial cells (HGECs) were used. Resveratrol was administered to diabetic and nondiabetic mice by oral gavage for 12 weeks starting at 8 weeks of age.. In db/db mice, resveratrol increased serum adiponectin levels and decreased albuminuria, glomerular matrix expansion, inflammation and apoptosis in the glomerulus. Resveratrol increased the phosphorylation of AMPK and silent information regulator T1 (SIRT1), and decreased phosphorylation of downstream effectors class O forkhead box (FoxO)1 and FoxO3a via increasing AdipoR1 and AdipoR2 in the renal cortex. Furthermore, resveratrol increased expression of PPARγ coactivator (PGC)-1α, estrogen-related receptor-1α, and phosphorylated acetyl-CoA carboxylase and decreased sterol regulatory element-binding protein 1. This effect lowered the content of nonesterified fatty acid and triacylglycerol in the kidneys, decreasing apoptosis, oxidative stress and activating endothelial nitric oxide synthase. Resveratrol prevented cultured HGECs from undergoing high-glucose-induced oxidative stress and apoptosis by activating the AMPK-SIRT1-PGC-1α axis and PPARα through increases in AdipoR1 and AdipoR2 expression.. These results suggest that resveratrol prevents diabetic nephropathy by ameliorating lipotoxicity, oxidative stress, apoptosis and endothelial dysfunction via increasing AdipoR1 and AdipoR2 expression.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Acetyl-CoA Carboxylase; AMP-Activated Protein Kinases; Animals; Apoptosis; bcl-2-Associated X Protein; Collagen Type IV; Deoxyguanosine; Diabetic Nephropathies; Fatty Acids; Fluorescent Antibody Technique; Forkhead Transcription Factors; In Situ Nick-End Labeling; Kidney; Male; Mice, Inbred C57BL; Nitric Oxide Synthase Type III; Phenotype; Phosphorylation; PPAR alpha; Receptors, Adiponectin; Resveratrol; Signal Transduction; Sirtuin 1; Sterol Regulatory Element Binding Protein 1; Stilbenes; Transforming Growth Factor beta1; Triglycerides

The development of diabetic nephropathy (DN) relays mainly on control of blood glucose and restrains hyperglycemic-induced oxidative stress. Hence, the effect administration of resveratrol (RSV) (5mg/kg) alone or in combination with rosuvastatin (RSU) (10mg/kg) on development and progression of diabetic nephropathy (DN) was evaluated. Oral treatment of diabetic rats with RSV alone or co-administered with RSU improved renal dysfunction indicated by a significant decrease in serum creatinine, urinary protein and urinary TGF-β1 when compared with diabetic control rats. Also, a significant increase in body weight, relative kidney weight with a significant decrease in serum glucose and glycated hemoglobin in diabetic treated groups when compared with diabetic control group. Hyperglycemic-induced oxidative stress in diabetic control rats indicated by a significant decrease in renal activities of catalase, superoxide dismutase, glutathione peroxidase and reduced glutathione level with a significant increase in malondialdehyde levels. However, oral treatment of diabetic rats with RSV alone or co-administered with RSU improved the antioxidant status back to control values. Similarly, mRNA analysis of quantitative real time-PCR substantiated that RSV with RSU notably normalizes the renal expression of TGF-β1, fibronectin, NF-κB/p65, Nrf2, Sirt1 and FoxO1 in the diabetic group of rats. The histopathological observations of the combined treated diabetic rats effectively protect the kidneys from hyperglycemic-induced oxidative damage. These findings confirmed the renoprotective effects of RSV with RSU treatment through improving glycemic control and attenuating oxidative stress damage in renal tissues of diabetic rats.

Topics: Animals; Antioxidants; Blood Glucose; Body Weight; Diabetes Mellitus, Experimental; Diabetic Nephropathies; Fibronectins; Gene Expression Regulation; Glycated Hemoglobin; Kidney; Male; Nerve Tissue Proteins; NF-kappa B; Oxidative Stress; Rats, Wistar; Real-Time Polymerase Chain Reaction; Resveratrol; Rosuvastatin Calcium; Sirtuin 1; Stilbenes; Transforming Growth Factor beta1

Renal interstitial fibrosis is a major pathologic feature of diabetic nephropathy, while the pathogenesis and therapeutic interventions of diabetic renal interstitial fibrosis are not well established. In this study, we first demonstrated that high glucose could induce renal fibroblast (NRK-49F) cell proliferation and activation to myofibroblasts, accompanied by a significant increase in the intracellular levels of reactive oxygen species (ROS) derived from nicotinamide adenine dinucleotide phosphate oxidase 4 (NOX4). ROS-mediated ERK1/2 activation was found to play a crucial role in high glucose-induced fibroblast proliferation and activation. Resveratrol, like the NOX4-targeting small interfering RNA (siRNA), markedly inhibited high glucose-induced fibroblast proliferation and activation by reducing NOX4-derived ROS production. It was then revealed that the increase in the expression of NOX4 induced by high glucose was due to the inactivation of AMP-activated protein kinase (AMPK), which could be reversed by resveratrol. Further in vivo investigation demonstrated that resveratrol treatment significantly attenuated renal fibrosis in db/db mice, accompanied by an evident increase in phospho-AMPK and decrease in NOX4. In summary, our results suggest that high glucose can directly promote renal fibroblasts proliferation and activation in a ROS-dependent manner, and resveratrol is a potential therapeutic agent against diabetic renal fibrosis via regulation of AMPK/NOX4/ROS signaling.. Resveratrol inhibits high glucose-induced NRK cell activation by decreasing NOX4-derived ROS. Resveratrol inhibits high glucose-induced NOX4 expression in NRK cells via activation of AMPK. ROS-activated ERK1/2 signaling is involved in high glucose-induced NRK cell activation. Resveratrol attenuated renal fibrosis in db/db mice via regulation of AMPK/NOX4/ROS signaling.

Topics: AMP-Activated Protein Kinases; Animals; Antioxidants; Cell Differentiation; Cell Line; Cell Proliferation; Diabetic Nephropathies; Fibroblasts; Fibrosis; Gene Expression Regulation; Glucose; Kidney; Male; Mice, Inbred C57BL; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Myofibroblasts; NADPH Oxidase 4; Rats; Reactive Oxygen Species; Resveratrol; Signal Transduction; Stilbenes

2,3,5,4'-Tetrahydroxystilbene-2-O-β-d-glucoside (TSG), an active component from the functional and medicinal herb Polygonum multiflorum Thunb, has the capacity of blocking angiotensin II (ANG II) signaling, a pathway within the renin-angiotensin system (RAS) which plays a critical role in the development of diabetic nephropathy (DN), and blockade of the RAS is currently used for the treatment of DN. Here we investigated the beneficial effect of TSG therapy on renal damage in the streptozotocin (STZ)-induced diabetes model. The STZ-treated C57BL/6J diabetic mice developed progressive albuminuria and renal tubular interstitial fibrosis within 10 weeks, accompanied by increased production of ANG II, fibronection, TGF-β, CTGF, TNF-α, RANTES and MCP-1 and decreased expression of slit diaphragm proteins in the kidney. The treatment of the diabetic mice with a TSG ameliorated kidney mass increase prevented albuminuria, and reduced tubular interstitial fibrosis. The TSG treatment suppressed the induction of fibronection, CTGF, TGF-β, and MCP-1 and reversed the decline of slit diaphragm proteins Neph-1, ZO-1, and FAT-1. These were accompanied by blockade of renal renin and ANG II accumulation induced by hyperglycemia. These data demonstrated that the inhibition of the RAS with TSG effectively prevented renal injury in diabetic nephropathy.

Topics: Albuminuria; Animals; Diabetes Mellitus, Experimental; Diabetic Nephropathies; Gene Expression Regulation; Glucosides; Kidney; Male; Mice; Mice, Inbred C57BL; RNA, Messenger; Stilbenes

The role of oxygen radicals are known for the pathogenesis of kidney damage. The aim of the present study was to investigate the antioxidative effects of melatonin, quercetin, and resveratrol on streptozotocin (STZ)-induced diabetic nephropathy in rats. A total of 35 male Wistar rats were divided into 5 groups as follows: control, diabetes mellitus (DM), DM + melatonin, DM + quercetin, and DM + resveratrol. All the injections started on the same day of single-dose STZ injection and continued for 30 days. At the end of this period, kidneys were removed and processed for routine histological procedures. Biochemical parameters and morphological changes were examined. In DM group, blood glucose levels were significantly increased, whereas body weights were decreased compared with the control group. Significant increases in blood urea nitrogen and tissue malondialdehyde (MDA) levels and decreases in superoxide dismutase and catalase activities were detected in DM group. Administration of melatonin, quercetin, and resveratrol significantly reduced these values. Melatonin was more efficient in reducing MDA levels than other antioxidants (p < 0.05). STZ-induced histopathological alterations including epithelial desquamation, swelling, intracytoplasmic vacuolization, brush border loss and peritubular infiltration. Additionally, basement membrane thickening and sclerotic changes were observed in glomerulus. Transforming growth factor-β1 positive cells were also increased. Melatonin, quercetin, and resveratrol significantly reduced these histopathological changes. Our results indicate that melatonin, quercetin, and resveratrol might be helpful in reducing diabetes-induced renal damage.

Topics: Animals; Antioxidants; Blood Glucose; Blood Urea Nitrogen; Catalase; Creatinine; Diabetes Mellitus, Experimental; Diabetic Nephropathies; Glutathione; Kidney; Male; Malondialdehyde; Melatonin; Quercetin; Rats, Wistar; Resveratrol; Stilbenes; Superoxide Dismutase

Sirt1 and nuclear factor-E2 related factor 2 (Nrf2)-anti-oxidant response element (ARE) anti-oxidative pathway play important regulatory roles in the pathological progression of diabetic nephropathy (DN) induced by advanced glycation-end products (AGEs). Polydatin (PD), a glucoside of resveratrol, has been shown to possess strong anti-oxidative bioactivity. Our previous study demonstrated that PD markedly resists the progression of diabetic renal fibrosis and thus, inhibits the development of DN. Whereas, whether PD could resist DN through regulating Sirt1 and consequently promoting Nrf2-ARE pathway needs further investigation. Here, we found that concomitant with decreasing RAGE (the specific receptor for AGEs) expression, PD significantly reversed the downregulation of Sirt1 in terms of protein expression and deacetylase activity and attenuated FN and TGF-β1 expression in GMCs exposed to AGEs. Under AGEs-treatment condition, PD could decrease Keap1 expression and promote the nuclear content, ARE-binding ability, and transcriptional activity of Nrf2. In addition, PD increased the protein levels of heme oxygenase 1 (HO-1) and superoxide dismutase 1 (SOD1), two target genes of Nrf2. The activation of Nrf2-ARE pathway by PD eventually led to the quenching of ROS overproduction sharply boosted by AGEs. Depletion of Sirt1 blocked Nrf2-ARE pathway activation and reversed FN and TGF-β1 downregulation induced by PD in GMCs challenged with AGEs. Along with reducing HO-1 and SOD1 expression, silencing of Nrf2 increased FN and TGF-β1 levels. PD treatment elevated Sirt1 and Nrf2 levels in the kidney tissues of diabetic rats, then improved the anti-oxidative capacity and renal dysfunction of diabetic models, and finally reversed the upregulation of FN and TGF-β1. Taken together, the resistance of PD on upregulated FN and TGF-β1 induced by AGEs via oxidative stress in GMCs is closely associated with its activation of Sirt1-Nrf2-ARE pathway.

Topics: Animals; Cells, Cultured; Diabetes Mellitus, Experimental; Diabetic Nephropathies; Fibronectins; Gene Silencing; Glucosides; Glycation End Products, Advanced; Mesangial Cells; NF-E2-Related Factor 2; Oxidative Stress; Rats; Rats, Sprague-Dawley; Receptor for Advanced Glycation End Products; Receptors, Immunologic; Response Elements; Sirtuin 1; Stilbenes; Transforming Growth Factor beta1; Up-Regulation

Resveratrol (RSV) is reported to have renoprotective activity against diabetic nephropathy, while the mechanisms underlying its function have not been fully elucidated. In this study, we investigate the effect and related mechanism of RSV against high glucose-induced epithelial to mesenchymal transition (EMT) in human tubular epithelial cells (HK-2). A typical EMT is induced by high glucose in HK-2 cells, accompanied by increased levels of reactive oxygen species (ROS). RSV exhibits a strong ability to inhibit high glucose-induced EMT by decreasing intracellular ROS levels via down-regulation of NADPH oxidase subunits NOX1 and NOX4. The activation of extracellular signal-regulated kinase (ERK1/2) is found to be involved in high glucose-induced EMT in HK-2 cells. RSV, like NADPH oxidase inhibitor diphenyleneiodonium, can block ERK1/2 activation induced by high glucose. Our results demonstrate that RSV is a potent agent against high glucose-induced EMT in renal tubular cells via inhibition of NADPH oxidase/ROS/ERK1/2 pathway.

Topics: Antioxidants; Cell Line; Diabetic Nephropathies; Drug Evaluation, Preclinical; Epithelial Cells; Epithelial-Mesenchymal Transition; Glucose; Humans; Kidney; Kidney Tubules; MAP Kinase Signaling System; NADPH Oxidase 1; NADPH Oxidase 4; NADPH Oxidases; Reactive Oxygen Species; Resveratrol; Stilbenes

To compare the protective effects of resveratrol, gliclazide, and losartan, at biochemical and histopathological levels, on the rat kidney with experimentally induced type 1 diabetes.. A total of 35 adult male Wistar rats were divided into control, diabetic, diabetic gliclazide, diabetic resveratrol, and diabetic losartan groups. For biochemical analysis, based on one of the kidneys, superoxide dismutase, malondialdehyde, and catalase were used for measurement. The other kidney was stained for histochemical and immunohistochemical markers and examined by light microscopy.. Nephropathy due to diabetes was developed at the end of the third week in the diabetic group: in the glomeruli, contraction from Bowman distance, diffuse mesangial matrix increasing and tubular dilation, and cytoplasmic vacuolar changes were observed. In tubulointerstitial areas, some tubular structures, an increased expression of VEGF was observed.. As a result, in diabetic rats, the effects of gliclazide, resveratrol, and losartan cure were equivalent to each other according to the parameters which were followed. Resveratrol, gliclazide, and losartan significantly protected renal glomeruli and the proximal and distal tubules.

Topics: Angiotensin II Type 1 Receptor Blockers; Animals; Antioxidants; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 1; Diabetic Nephropathies; Enzyme-Linked Immunosorbent Assay; Gliclazide; Hypoglycemic Agents; Immunohistochemistry; Kidney; Losartan; Male; Rats; Rats, Wistar; Resveratrol; Stilbenes

Adiponectin is an adipocyte derived protein that plays pivotal roles in anti-oxidation, anti-inflammatory and insulin-sensitizing properties by activating two receptors, AdipoR1 and AdipoR2. Recent studies have shown that the down-regulation of AdipoR1 is a known cause of diabetic nephropathy (DN). Resveratrol (Resv), a natural polyphenol, has been identified as a potent activator of forkhead transcription factor O1 (FoxO1) which can up-regulate the expression of AdipoR1. In the present study, we have investigated whether Resv can up-regulate the expression of AdipoR1 by activating FoxO1 that is in kidney of DN rats and mesangial cells (MCs) cultured in high glucose (HG, 30 mmol/L) medium. In vivo, we show that, in the renal cortex of diabetic rats, the expression of AdipoR1 was significantly reduced and correlated with an increase in the generation of malondialdehyde (MDA), Collagen IV and fibronectin proteins. However, administration with Resv significantly increased the expression of AdipoR1. This correlated with not only a decrease in generation of MDA, Collagen IV and fibronectin proteins levels but also more improved kidney pathological and biochemical indicators changes. In vitro, we show that HG-induced depression of FoxO1 activity was associated with the expression of Adipor1 in MCs. Treatment with Resv (20 μmol/L) caused an elevation in the activity of FoxO1 and a significantly increase in the expression of AdipoR1. Furthermore, inhibition of FoxO1 through short hairpin RNA markedly reduced the expression of Adipor1 in MCs cultured by Resv. In conclusion, Resv can significantly increase the expression of AdipoR1 by activating FoxO1 in diabetic kidney. These data also suggest that Resv may serve as a promising agent for preventing or treating DN.

Topics: Animals; Body Weight; Collagen Type IV; Diabetic Nephropathies; Disease Models, Animal; Fibronectins; Forkhead Transcription Factors; Gene Expression Regulation; Glucose; Kidney; Lipid Peroxidation; Male; Mesangial Cells; Nerve Tissue Proteins; Oxidative Stress; Rats; Receptors, Adiponectin; Resveratrol; Stilbenes

Various mechanisms with a complex integrating paradigm have been implicated in diabetic complications. The present study was aimed to evaluate the aldose reductase (AR) and advanced glycation end products (AGEs) inhibitory activity of resveratrol (RSV) and its potential in the treatment of diabetic complications such as cataract and nephropathy.. RSV was studied for its inhibitory activity against rat lens AR (RLAR) and rat kidney AR (RKAR) in vitro along with its ability to inhibit formation of AGEs. Anticataract activity of RSV was demonstrated using sugar induced lens opacity model in isolated cattle lens. Furthermore the involvement of RSV in streptozotocin-induced diabetic nephropathy was investigated by assessing the key markers of kidney function along with the formation of AGEs. The potent AR inhibitor, fidarestat was as a standard.. RSV exhibited inhibitory activity against RLAR and RKAR with IC50 values of 4.99 μg/ml (21.9 μM) and 5.49 μg/ml (24.5 μM), respectively. It also showed a significant inhibition of AGEs formation in vitro. In sugar-induced lens opacity model, RSV displayed a significant protective effect preventing opacification and formation of polyols in cattle lens. RSV significantly improved glycaemic status and renal function in diabetic rats with a significant decrease in the formation of AGEs in the kidneys.. The results obtained in this study underline the potential of RSV as a possible therapeutic agent against long-term diabetic complications.

Topics: Aldehyde Reductase; Animals; Cataract; Cattle; Diabetes Mellitus, Experimental; Diabetic Nephropathies; Disease Models, Animal; Glycation End Products, Advanced; Imidazolidines; Inhibitory Concentration 50; Kidney Function Tests; Lens, Crystalline; Male; Rats; Rats, Wistar; Resveratrol; Stilbenes; Streptozocin

Diabetic nephropathy (DN) is the major cause of end-stage renal disease. Resveratrol has been shown to ameliorate hyperglycemia in diabetic rats. However, the effects of resveratrol on DN remain unknown. The aim of the present study is to investigate the effects of resveratrol on early-stage DN. Diabetes was induced by streptozotocin injection in male Wistar rats. The diabetic rats were treated with resveratrol at a dose of 20 mg/kg body weight for 8 weeks. Plasma glucose, creatinine, kidney/body weight ratio, and 24-h urinary protein were determined. The renal pathological changes were examined with periodic acid Schiff staining, and renal mesangial cells were cultured in high glucose concentrations with indicated concentrations of resveratrol (2.5, 5.0, and 10.0 μmol/L). The proliferation of mesangial cells was evaluated by methylthiazoletetrazolium assay. Expressions of glutathione S-transferases Mu (GSTM) and nuclear factor erythroid 2-related factor 2 (Nrf2) were detected by western blot, and apoptosis was analyzed using a flow cytometer. Resveratrol reduced plasma glucose, creatinine, and urinary protein excretion, and attenuated renal hypertrophy. Moreover, resveratrol also reduced the expression of GSTM in diabetic rats. In vitro, resveratrol inhibited the proliferation of mesangial cells caused by high glucose and down-regulated GSTM and Nrf2 expressions in a dose-dependent manner. These findings suggest that resveratrol help prevent the progression of DN. The renoprotection by resveratrol is in part mediated through the inhibition of high glucose-induced rat mesangial cell proliferation and downregulation of GSTM expression.

Topics: Animals; Diabetic Nephropathies; Down-Regulation; Glucose; Glutathione Transferase; Humans; Kidney; Male; Mesangial Cells; NF-E2-Related Factor 2; Rats; Rats, Wistar; Resveratrol; Stilbenes

Angiogenesis plays an important role in the pathogenesis of diabetic nephropathy (DN). In the present study, we investigated the therapeutic potential of resveratrol, a polyphenol with antiangiogenic activity in DN. In a type 1 diabetic rat model, resveratrol treatment blunted the increases of urine albumin excretion, kidney weight and creatinine clearance rate. The increases of glomerular diameter, mesangium accumulation, glomerular basement membrane thickness and renal fibrosis in diabetic rats were also reduced by resveratrol treatment. In the diabetic kidney, increased expression of vascular endothelial growth factor (VEGF), Flk-1 and angiopoietin 2, and reduced expression of Tie-2 were observed. These changes in angiogenic hormones and associated receptors were attenuated by resveratrol treatment. No changes in angiopoietin 1 expression were detected among each group of rats. Resveratrol also significantly downregulated high glucose-induced VEGF and Flk-1 expressions in cultured mouse glomerular podocytes and endothelial cells, respectively. These effects were attenuated by knocking-down silent information regulator 1 (Sirt1) expression. In contrast, upregulation of Sirt1 in cultured endothelial cells reduced Flk-1 expression. Increased permeability and cellular junction disruption of cultured endothelial cells caused by VEGF were also inhibited by resveratrol pretreatment. Taken together, the present study demonstrated that resveratrol may attenuate DN via modulating angiogenesis.

Topics: Angiogenesis Modulating Agents; Angiopoietin-2; Animals; Diabetes Mellitus, Experimental; Diabetic Nephropathies; Male; Mice; Rats; Rats, Sprague-Dawley; Receptor, TIE-2; Resveratrol; Sirtuin 1; Stilbenes; Vascular Endothelial Growth Factor A

Many of the effects of resveratrol are consistent with the activation of AMP-activated protein kinase (AMPK), silent information regulator T1 (SIRT1) and peroxisome proliferator-activated receptor (PPAR)γ co-activator 1α (PGC-1α), which play key roles in the regulation of lipid and glucose homeostasis, and in the control of oxidative stress. We investigated whether resveratrol has protective effects on the kidney in type 2 diabetes.. Four groups of male C57BLKS/J db/m and db/db mice were used in this study. Resveratrol was administered via gavage to diabetic and non-diabetic mice, starting at 8 weeks of age, for 12 weeks.. The db/db mice treated with resveratrol had decreased albuminuria. Resveratrol ameliorated glomerular matrix expansion and inflammation. Resveratrol also lowered the NEFA and triacylglycerol content of the kidney, and this action was related to increases in the phosphorylation of AMPK and the activation of SIRT1-PGC-1α signalling and of the key downstream effectors, the PPARα-oestrogen-related receptor (ERR)-1α-sterol regulatory element-binding protein 1 (SREBP1). Furthermore, resveratrol decreased the activity of phosphatidylinositol-3 kinase (PI3K)-Akt phosphorylation and class O forkhead box (FOXO)3a phosphorylation, which resulted in a decrease in B cell leukaemia/lymphoma 2 (BCL-2)-associated X protein (BAX) and increases in BCL-2, superoxide dismutase (SOD)1 and SOD2 production. Consequently, resveratrol reversed the increase in renal apoptotic cells and oxidative stress, as reflected by renal 8-hydroxy-deoxyguanosine (8-OH-dG), urinary 8-OH-dG and isoprostane concentrations. Resveratrol prevented high-glucose-induced oxidative stress and apoptosis in cultured mesangial cells through the phosphorylation of AMPK and activation of SIRT1-PGC-1α signalling and the downstream effectors, PPARα-ERR-1α-SREBP1.. The results suggest that resveratrol prevents diabetic nephropathy in db/db mice by the phosphorylation of AMPK and activation of SIRT1-PGC-1α signalling, which appear to prevent lipotoxicity-related apoptosis and oxidative stress in the kidney.

Topics: AMP-Activated Protein Kinases; Animals; Cells, Cultured; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Enzyme Activation; Kidney; Lipid Metabolism; Lipotropic Agents; Male; Mesangial Cells; Mice; Mice, Inbred C57BL; Mice, Mutant Strains; Oxidative Stress; Protective Agents; Protein Processing, Post-Translational; Resveratrol; RNA Interference; Signal Transduction; Sirtuin 1; Stilbenes; Transcription Factors

A number of studies have recently demonstrated the involvement of nuclear factor-kappa B (NF-κB) activation and the subsequent coordinated inflammatory responses in the pathogenesis of diabetic nephropathy (DN). Polydatin has been shown to have the ability of anti-adhesive inflammation. However, the possible protective and beneficial effects of polydatin on DN via suppressing inflammatory damage and extracellular matrix (ECM) accumulation are not fully elucidated. We found that the polydatin could inhibit the induction and activity of NF-κB, and meanwhile ameliorating ECM accumulation in streptozotocin-diabetic rats. We aimed to investigate the effect of polydatin on fibronectin (FN) protein expression, and to elucidate its potential mechanism involving the NF-κB inflammatory signaling pathway in rat glomerular mesangial cells (GMCs) cultured under high glucose. The results revealed that polydatin significantly suppressed high glucose-induced FN production, inhibited NF-κB nuclear translocation, reduced the DNA-binding activity of NF-κB, as well as decreased the protein expression of ICAM-1 and TGF-β in GMCs. These findings suggested that polydatin significantly represses high glucose-induced FN expression in rat GMCs, which may be closely related to its inhibition of the NF-κB signaling pathway. Hence, we elucidated the potential mechanisms of the anti-inflammatory effects and ECM accumulation alleviation of polydatin in GMCs of DN in vitro.

Topics: Active Transport, Cell Nucleus; Animals; Anti-Inflammatory Agents; Cell Nucleus; Cells, Cultured; Cytoprotection; Diabetes Mellitus, Experimental; Diabetic Nephropathies; Drugs, Chinese Herbal; Fibronectins; Gene Expression; Glucosides; I-kappa B Proteins; Intercellular Adhesion Molecule-1; Kidney; Male; Mesangial Cells; NF-kappa B; NF-KappaB Inhibitor alpha; Organ Size; Protein Binding; Proteolysis; Rats; Rats, Sprague-Dawley; Signal Transduction; Stilbenes; Transforming Growth Factor beta

Reactive oxygen species production has recently been established as an essential contributor in the development of diabetic nephropathy (DN). Resveratrol, a natural anti-oxidants with biological activity, is known to be an activator of sirtuin1 (Sirt1). Forkhead transcription factor O1 (FoxO1) plays a role not only in regulating metabolism but also in oxidant stress. The present study was carried out to examine whether resveratrol had protective effect on diabetic kidney by modulation of the Sirt1/FoxO1 pathway. To investigate the effect of FoxO1 on oxidant stress, male Sprague-Dawley rats were injected with a single dose of 60 mg/kg streptozotocin (STZ) to induce diabetes. Here we show that the FoxO1 activity was significantly reduced and with a concomitant decrease in the expression of FoxO1 target gene, catalase in diabetic kidney. The FoxO1 downregulation correlated with an increase in the generation of malondialdehyde (MDA), a decrease in the activity of SOD and an increase in the expression of collagen IV and fibronectin proteins in renal cortex of diabetic rats. Treatment with the sirtuin agonist resveratrol, with an increase in the expression of Sirt1, significantly increased FoxO1 activity in diabetic kidney. This correlated with a decrease in the generation of MDA, an increase in the activity of SOD, a partial reversal of collagen IV and fibronectin proteins levels and more improved kidney pathological and biochemical indicators changes. Together these results indicate that it is characterized by decreased activity of FoxO1 in diabetic kidney. These data also suggest that modulation of the Sirt1/FoxO1 pathway may be a potentially useful therapeutic target for DN.

Topics: Animals; Antioxidants; Body Weight; Catalase; Collagen Type IV; Diabetic Nephropathies; Fibronectins; Forkhead Transcription Factors; Gene Expression Regulation; Kidney; Male; Nerve Tissue Proteins; Organ Size; Rats; Rats, Sprague-Dawley; Reactive Oxygen Species; Resveratrol; Sirtuin 1; Stilbenes

Despite the beneficial effects of resveratrol (RSV) on cardiovascular disease and life span, its effects on type 2 diabetic nephropathy remain unknown. This study examined the renoprotective effects of RSV in db/db mice, a model of type 2 diabetes.. db/db mice were treated with RSV (0.3% mixed in chow) for 8 weeks. We measured urinary albumin excretion (UAE), histological changes (including mesangial expansion, fibronectin accumulation, and macrophage infiltration), oxidative stress markers (urinary excretion and mitochondrial content of 8-hydroxy-2'-deoxyguanosine [8-OHdG], nitrotyrosine expression), and manganese-superoxide dismutase (Mn-SOD) activity together with its tyrosine-nitrated modification and mitochondrial biogenesis in the kidney. Blood glucose, glycated hemoglobin, and plasma lipid profiles were also measured. The phosphorylation of 5'-AMP-activated kinase (AMPK) and expression of silent information regulator 1 (SIRT1) in the kidney were assessed by immunoblotting.. RSV significantly reduced UAE and attenuated renal pathological changes in db/db mice. Mitochondrial oxidative stress and biogenesis were enhanced in db/db mice; however, Mn-SOD activity was reduced through increased tyrosine-nitrated modification. RSV ameliorated such alterations and partially improved blood glucose, glycated hemoglobin, and abnormal lipid profile in db/db mice. Activation of AMPK was decreased in the kidney of db/db mice compared with db/m mice. RSV neither modified AMPK activation nor SIRT1 expression in the kidney.. RSV ameliorates renal injury and enhanced mitochondrial biogenesis with Mn-SOD dysfunction in the kidney of db/db mice, through improvement of oxidative stress via normalization of Mn-SOD function and glucose-lipid metabolism. RSV has antioxidative activities via AMPK/SIRT1-independent pathway.

Topics: AMP-Activated Protein Kinases; Animals; Blood Glucose; Blotting, Western; Cells, Cultured; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Immunohistochemistry; Immunoprecipitation; Kidney; Male; Mice; Oxidative Stress; Resveratrol; Reverse Transcriptase Polymerase Chain Reaction; Signal Transduction; Sirtuin 1; Stilbenes; Superoxide Dismutase

Diabetic nephropathy (DN) is the major cause of end-stage renal disease. The early changes in DN are characterized by an increased in kidney size, glomerular volume, and kidney function, followed by the accumulation of glomerular extracellular matrix, increased urinary albumin excretion (UAE), glomerular sclerosis, and tubular fibrosis. Resveratrol (RSV) has been shown to ameliorate hyperglycemia and hyperlipidemia in streptozotocin-induced diabetic rats. In the present study, we examined the beneficial effects of RSV on DN and explored the possible mechanism of RSV action. Male Sprague-Dawley rats were injected with streptozotocin at 65mg/kg body weight. The induction of diabetes mellitus (DM) was confirmed by a fasting plasma glucose level ≥300mg/dL and symptoms of polyphagia and polydipsia. The DM rats were treated with or without RSV at 0.75mg/kg body weight 3 times a day for 8 weeks. Animals were sacrificed and kidney histology was examined by microscopy. Urinary albumin excretion, glomerular hypertrophy and expressions of fibronectin, collagen IV, and TGF-β in the glomeruli were alleviated in RSV-treated DM rats, but not in untreated DM rats. In addition, RSV treatment reduced the thickness of the glomerular basement membrane (GBM) to the original thickness and increased nephrin expressions to normal levels in DM rats. Moreover, RSV inhibited phosphorylation of smad2, smad3 and ERK1/2 in diabetic rat kidneys. This is the first report showing that RSV alleviates early glomerulosclerosis in DN through TGF-β/smad and ERK1/2 inhibition. In addition, podocyte injuries of diabetic kidneys are lessened by RSV.

Topics: Animals; Collagen Type IV; Diabetes Mellitus, Experimental; Diabetic Nephropathies; Disease Models, Animal; Fibronectins; Hypoglycemic Agents; Kidney; Male; Membrane Proteins; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Phosphorylation; Rats; Rats, Sprague-Dawley; Resveratrol; Signal Transduction; Smad Proteins; Stilbenes; Transforming Growth Factor beta

Hyperglycemia-mediated oxidative stress plays a crucial role in the progression of diabetic nephropathy. Hence, the present study was hypothesized to explore the renoprotective nature of resveratrol by assessing markers of oxidative stress, proinflammatory cytokines and antioxidant competence in streptozotocin-nicotinamide-induced diabetic rats. Oral administration of resveratrol to diabetic rats showed a significant normalization on the levels of creatinine clearance, plasma adiponectin, C-peptide and renal superoxide anion, hydroxyl radical, nitric oxide, TNF-α, IL-1β, IL-6 and NF-κB p65 subunit and activities of renal aspartate transaminase, alanine transaminase and alkaline phosphatase in comparison with diabetic rats. The altered activities of renal aldose reductase, sorbitol dehydrogenase and glyoxalase-I and elevated level of serum advanced glycation end products in diabetic rats were also reverted back to near normalcy. Further, resveratrol treatment revealed a significant improvement in superoxide dismutase, catalase, glutathione peroxidase, glutathione-S-transferase and glutathione reductase activities and vitamins C and E, and reduced glutathione levels, with a significant decline in lipid peroxides, hydroperoxides and protein carbonyls levels in diabetic kidneys. Similarly, mRNA and protein analyses substantiated that resveratrol treatment notably normalizes the renal expression of Nrf2/Keap1and its downstream regulatory proteins in the diabetic group of rats. Histological and ultrastructural observations also evidenced that resveratrol effectively protects the kidneys from hyperglycemia-mediated oxidative damage. These findings demonstrated the renoprotective nature of resveratrol by attenuating markers of oxidative stress in renal tissues of diabetic rats.

Topics: Animals; Antioxidants; Base Sequence; Cytokines; Diabetic Nephropathies; DNA Primers; Hyperglycemia; Inflammation Mediators; Intracellular Signaling Peptides and Proteins; Kelch-Like ECH-Associated Protein 1; Kidney; Male; Microscopy, Electron, Transmission; NF-E2-Related Factor 2; Oxidative Stress; Polymerase Chain Reaction; Proteins; Rats; Rats, Wistar; Resveratrol; Stilbenes

Diabetic nephropathy (DN) has been recognized as the leading cause of end-stage renal disease. Resveratrol (RSV), a polyphenolic compound, has been indicated to possess an insulin-like property in diabetes. In the present study, we aimed to investigate the renoprotective effects of RSV and delineate its underlying mechanism in early-stage DN.. The protective effects of RSV on DN were evaluated in streptozotocin (STZ)-induced diabetic rats.. The plasma glucose, creatinine, and blood urea nitrogen were significantly elevated in STZ-induced diabetic rats. RSV treatment markedly ameliorated hyperglycemia and renal dysfunction in STZ-induced diabetic rats. The diabetes-induced superoxide anion and protein carbonyl levels were also significantly attenuated in RSV-treated diabetic kidney. The AMPK protein phosphorylation and expression levels were remarkably reduced in diabetic renal tissues. In contrast, RSV treatment significantly rescued the AMPK protein expression and phosphorylation compared to non-treated diabetic group. Additionally, hyperglycemia markedly enhanced renal production of proinflammatory cytokine IL-1β. RSV reduced IL-1β but increased TNF-α and IL-6 levels in the diabetic kidneys.. Our findings suggest that RSV protects against oxidative stress, exhibits concurrent proinflammation and anti-inflammation, and up-regulates AMPK expression and activation, which may contribute to its beneficial effects on the early stage of DN.

Topics: AMP-Activated Protein Kinases; Animals; Cytokines; Diabetes Mellitus, Experimental; Diabetic Nephropathies; Disease Progression; Gene Expression; Male; Oxidative Stress; Rats; Rats, Long-Evans; Resveratrol; Stilbenes

Recent studies suggest the involvement of the adenosine monophosphate-activated serine/threonine protein kinase (AMPK) pathway in the pathogenesis of diabetic nephropathy (DN). Resveratrol, an agent that activates AMPK, may have the potential to protect against the development of DN. This study was designed to investigate the therapeutic effects of resveratrol on renal hypertrophy in early-stage diabetes and the underlying mechanisms.. Molecular and structural changes involved in the pathogenesis of DN were tested in a rat model of early-stage diabetes. Renal mesangial cells (RMCs) were cultured in media containing different concentrations of glucose with or without resveratrol. Cellular DNA synthesis was assayed by measuring (3)H-thymidine incorporation. The phosphorylation status of AMPK, eukaryotic translation initiation factor 4E binding protein 1 (4E-BP1), and phospho- ribosomal protein S6 (S6) was analyzed by Western blot.. Resveratrol reduced plasma creatinine and urinary albumin excretion and attenuated renal hypertrophy without affecting blood glucose levels. Moreover, resveratrol activated AMPK and inhibited phosphorylation of 4E-BP1 and S6 in diabetic rat kidneys. In vitro, resveratrol blocked high glucose-induced dephosphorylation of AMPK and phosphorylation of 4E-BP1 and S6 and strongly inhibited both the DNA synthesis and proliferation of RMCs.. These findings suggest the possibility that resveratrol exerts antiproliferative, antihypertrophic effects by activating AMPK and reducing 4E-BP1 and S6 phosphorylation, thus suppressing the development and progression of DN.

Topics: AMP-Activated Protein Kinase Kinases; Animals; Diabetic Nephropathies; Hypertrophy; Kidney; Male; Phosphorylation; Protein Kinases; Rats; Rats, Sprague-Dawley; Resveratrol; Stilbenes

Oxidative stress caused by hyperglycaemia is believed to be a major molecular mechanism underlying diabetic nephropathy. 2,3,5,4'-tetrahydroxystilbene-2-O-β-d-glucoside (TSG), an active component extract from Polygonum multiflorum Thunb, exhibits antioxidative and anti-inflammatory effects. Possible protective mechanisms of TSG on diabetic nephropathy were investigated in rats and cultured rat mesangial cells. Total cholesterol and triglyceride levels of diabetic rats were clearly increased and these increases were diminished by treatment with TSG. Treatment of diabetic rats with TSG also significantly reduced blood urea nitrogen, creatinine, 24 h urinary protein levels, and kidney weight/body weight. The activities of superoxide dismutase and glutathione peroxidase in renal homogenate were increased markedly, whereas malonaldehyde levels were decreased significantly in TSG-treated diabetic rats. TSG dramatically inhibited diabetes-induced overexpression of TGF-β1 and COX-2, and restored the decrease of SIRT1 expression in diabetic rats. High glucose-induced overexpression of TGF-β1 in cultured mesangial cells was significantly inhibited, whereas the decease of SIRT1 expression was restored by pretreatment of TSG. Nicotinamide, the inhibitor of SIRT1, partially relieved the inhibitory effect of TSG on TGF-β1 expression under high glucose condition. These findings indicate that the protective mechanisms of TSG on diabetic nephropathy are involved in the alleviation of oxidative stress injury and overexpression of COX-2 and TGF-β1, partially via activation of SIRT1.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Antioxidants; Biomarkers; Cell Line; Cyclooxygenase 2; Diabetic Nephropathies; Dose-Response Relationship, Drug; Glucosides; Histone Deacetylase Inhibitors; Hyperglycemia; Kidney Cortex; Male; Mesangial Cells; Oxidative Stress; Random Allocation; Rats; Rats, Sprague-Dawley; Signal Transduction; Sirtuin 1; Stilbenes; Transforming Growth Factor beta1

Resveratrol has been reported to have a wide variety of biological effects. However, little is known regarding its role on phosphorylation of histone H3, MAP kinase p38, SIR2 and p53 in type I diabetic nephropathy (DN). Hence, the present study was undertaken to examine changes in the above said parameters by resveratrol treatment. Male Sprague-Dawley rats were rendered diabetic using a single dose of streptozotocin (55 mg/kg, i.p.). DN was assessed by measurements of blood urea nitrogen and creatinine levels. Phosphorylation of histone H3, SIR2, p53 and MAP kinase p38 expression were examined by western blotting. This study reports that treatment of resveratrol prevents the decrease in the expression of SIR2 in diabetic kidney. It also prevents increase in p38, p53 expression and dephosphorylation of histone H3 in diabetic kidney. This is the first report which suggests that protection against development of diabetic nephropathy by resveratrol treatment involves change in phosphorylation of histone H3, expression of Sir-2, p53 and p38 in diabetic kidney.

Topics: Animals; Antioxidants; Diabetes Mellitus, Experimental; Diabetic Nephropathies; Histones; Male; Oxidative Stress; p38 Mitogen-Activated Protein Kinases; Phosphorylation; Rats; Rats, Sprague-Dawley; Resveratrol; Sirtuin 1; Sirtuins; Stilbenes; Streptozocin; Tumor Suppressor Protein p53

Diabetic nephropathy is a serious microvascular complication and one of the main causes of end-stage renal disease. Various studies have revealed that increased oxidative stress is a major pathophysiological mechanism which is involved in the etiology of diabetic nephropathy. Resveratrol, a polyphenolic phytoalexin present in red wine, is known to possess potent antioxidant properties and thus we aimed to examine its effect on renal function and oxidative stress in streptozotocin (STZ)-induced diabetic rats. Diabetes was induced by a single intraperitoneal injection of STZ (65 mg/kg) in rats. After 4 weeks of STZ injection, rats were divided into four groups: the control rats, diabetic rats and diabetic rats treated with resveratrol (5 and 10 mg/kg, orally) respectively from week 4 up till week 6. At the termination of the experiments, urine albumin excretion, urine output, serum creatinine, blood urea nitrogen, creatinine and urea clearance were measured. The levels of the renal oxidative stress markers malonaldehyde and glutathione and the antioxidant enzymes superoxide dismutase and catalase were measured in kidney homogenate. STZ-injected rats showed significant increases in blood glucose, polyuria, proteinuria and a decrease in body weight compared with age-matched control rats. After 6 weeks, diabetic rats exhibited renal dysfunction, as evidenced by reduced creatinine and urea clearance, and proteinuria along with a marked increase in oxidative stress, as determined by lipid peroxidation and activities of key antioxidant enzymes. Treatment with resveratrol significantly attenuated renal dysfunction and oxidative stress in diabetic rats. The present study reinforces the important role of oxidative stress in diabetic kidney and points towards the possible antioxidative mechanism being responsible for the renoprotective action of resveratrol.

Topics: Animals; Antioxidants; Catalase; Diabetes Mellitus, Experimental; Diabetic Nephropathies; Dose-Response Relationship, Drug; Glutathione; Kidney; Kidney Function Tests; Lipid Peroxidation; Male; Malondialdehyde; Oxidative Stress; Phenols; Phytoalexins; Phytotherapy; Plant Extracts; Rats; Rats, Sprague-Dawley; Resveratrol; Sesquiterpenes; Stilbenes; Superoxide Dismutase; Terpenes