scholarly journals The antioxidant silybin prevents high glucose-induced oxidative stress and podocyte injury in vitro and in vivo

2013 ◽  
Vol 305 (5) ◽  
pp. F691-F700 ◽  
Author(s):  
Khaled Khazim ◽  
Yves Gorin ◽  
Rita Cassia Cavaglieri ◽  
Hanna E. Abboud ◽  
Paolo Fanti
Keyword(s):  
Diabetic Nephropathy ◽  
Nadph Oxidase ◽  
High Glucose ◽  
Drop Out ◽  
Superoxide Production ◽  
Kidney Cortex ◽  
Active Constituent ◽  
Podocyte Injury

Podocyte injury, a major contributor to the pathogenesis of diabetic nephropathy, is caused at least in part by the excessive generation of reactive oxygen species (ROS). Overproduction of superoxide by the NADPH oxidase isoform Nox4 plays an important role in podocyte injury. The plant extract silymarin is attributed antioxidant and antiproteinuric effects in humans and in animal models of diabetic nephropathy. We investigated the effect of silybin, the active constituent of silymarin, in cultures of mouse podocytes and in the OVE26 mouse, a model of type 1 diabetes mellitus and diabetic nephropathy. Exposure of podocytes to high glucose (HG) increased 60% the intracellular superoxide production, 90% the NADPH oxidase activity, 100% the Nox4 expression, and 150% the number of apoptotic cells, effects that were completely blocked by 10 μM silybin. These in vitro observations were confirmed by similar in vivo findings. The kidney cortex of vehicle-treated control OVE26 mice displayed greater Nox4 expression and twice as much superoxide production than cortex of silybin-treated mice. The glomeruli of control OVE26 mice displayed 35% podocyte drop out that was not present in the silybin-treated mice. Finally, the OVE26 mice experienced 54% more pronounced albuminuria than the silybin-treated animals. In conclusion, this study demonstrates a protective effect of silybin against HG-induced podocyte injury and extends this finding to an animal model of diabetic nephropathy.

scholarly journals Effect of Tongxinluo on Nephrin Expression via Inhibition of Notch1/Snail Pathway in Diabetic Rats

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Fangqiang Cui ◽  
Dawei Zou ◽  
Yanbin Gao ◽  
Na Zhang ◽  
Jinyang Wang ◽  
...  
Keyword(s):  
Diabetic Nephropathy ◽  
Molecular Mechanism ◽  
High Glucose ◽  
Diabetic Rats ◽  
In Vitro Studies ◽  
Podocyte Injury ◽  
Snail Expression ◽  
Renal Structure

Podocyte injury is an important mechanism of diabetic nephropathy (DN). Accumulating evidence suggests that nephrin expression is decreased in podocyte in DN. Moreover, it has been demonstrated that tongxinluo (TXL) can ameliorate renal structure disruption and dysfunction in DN. However, the effect of TXL on podocyte injury in DN and its molecular mechanism is unclear. In order to explore the effect of TXL on podocyte injury and its molecular mechanism in DN, our in vivo and in vitro studies were performed. Our results showed that TXL increased nephrin expression in diabetic rats and in high glucose cultured podocyte. Meanwhile, TXL decreased ICN1 (the intracellular domain of notch), HES1, and snail expression in podocyte in vivo and in vitro. More importantly, we found that TXL protected podocyte from injury in DN. The results demonstrated that TXL inhibited the activation of notch1/snail pathway and increased nephrin expression, which may be a mechanism of protecting effect on podocyte injury in DN.

MAD2B contributes to podocyte injury of diabetic nephropathy via inducing cyclin B1 and Skp2 accumulation

2015 ◽  
Vol 308 (7) ◽  
pp. F728-F736 ◽  
Author(s):  
Hua Su ◽  
Qiang Wan ◽  
Xiu-Juan Tian ◽  
Fang-Fang He ◽  
Pan Gao ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Diabetic Nephropathy ◽  
High Glucose ◽  
Cyclin B1 ◽  
Cell Cycle Checkpoints ◽  
Checkpoint Control ◽  
Podocyte Injury ◽  
A Cell

It is well documented that mitotic arrest deficiency (MAD)2B can inhibit the anaphase-promoting complex/cyclosome (APC/C) via cadherin (Cdh)1 and, consequently, can destroy the effective mitotic spindle checkpoint control. Podocytes have been observed to rapidly detach and die when being forced to bypass cell cycle checkpoints. However, the role of MAD2B, a cell cycle regulator, in podocyte impairment of diabetic nephropathy (DN) is unclear. In the present study, we investigated the significance of MAD2B in the pathogenesis of DN in patients, an animal model, and in vitro podocyte cultures. By Western blot and immunohistochemistry analyses, we found that MAD2B was evidently upregulated under high glucose milieu in vivo and in vitro, whereas Cdh1 was inhibited with high glucose exposure. Overexpression of MAD2B in podocytes by plasmid DNA transfection suppressed expression of Cdh1 and triggered the accumulation of cyclin B1 and S phase kinase-associated protein (Skp)2, two key molecules involving in cell cycle regulation, and the subsequent podocyte insult. In contrast, MAD2B deletion alleviated the high glucose-induced reduction of Cdh1 as well as the elevation of cyclin B1 and Skp2, which rescued the podocyte from damage. Taken together, our data demonstrate that MAD2B may play an important role in high glucose-mediated podocyte injury of DN via modulation of Cdh1, cyclin B1, and Skp2 expression.

scholarly journals High Glucose and Lipopolysaccharide Prime NLRP3 Inflammasome via ROS/TXNIP Pathway in Mesangial Cells

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Hong Feng ◽  
Junling Gu ◽  
Fang Gou ◽  
Wei Huang ◽  
Chenlin Gao ◽  
...  
Keyword(s):  
Diabetic Nephropathy ◽  
Nlrp3 Inflammasome ◽  
High Glucose ◽  
Mesangial Cells ◽  
Central Component ◽  
Dependent Manner ◽  
Glomerular Mesangial Cells ◽  
Interacting Protein

While inflammation is considered a central component in the development in diabetic nephropathy, the mechanism remains unclear. The NLRP3 inflammasome acts as both a sensor and a regulator of the inflammatory response. The NLRP3 inflammasome responds to exogenous and endogenous danger signals, resulting in cleavage of procaspase-1 and activation of cytokines IL-1β, IL-18, and IL-33, ultimately triggering an inflammatory cascade reaction. This study observed the expression of NLRP3 inflammasome signaling stimulated by high glucose, lipopolysaccharide, and reactive oxygen species (ROS) inhibitor N-acetyl-L-cysteine in glomerular mesangial cells, aiming to elucidate the mechanism by which the NLRP3 inflammasome signaling pathway may contribute to diabetic nephropathy. We found that the expression of thioredoxin-interacting protein (TXNIP), NLRP3, and IL-1βwas observed by immunohistochemistry in vivo. Simultaneously, the mRNA and protein levels of TXNIP, NLRP3, procaspase-1, and IL-1βwere significantly induced by high glucose concentration and lipopolysaccharide in a dose-dependent and time-dependent manner in vitro. This induction by both high glucose and lipopolysaccharide was significantly inhibited by N-acetyl-L-cysteine. Our results firstly reveal that high glucose and lipopolysaccharide activate ROS/TXNIP/ NLRP3/IL-1βinflammasome signaling in glomerular mesangial cells, suggesting a mechanism by which inflammation may contribute to the development of diabetic nephropathy.

scholarly journals Increased long noncoding RNA maternally expressed gene 3 contributes to podocyte injury induced by high glucose through regulation of mitochondrial fission

2020 ◽  
Vol 11 (9) ◽  
Author(s):  
Qiongxia Deng ◽  
Ruowei Wen ◽  
Sirui Liu ◽  
Xiaoqiu Chen ◽  
Shicong Song ◽  
...  
Keyword(s):  
High Glucose ◽  
Noncoding Rna ◽  
Diabetic Kidney Disease ◽  
Mitochondrial Fission ◽  
Diabetic Mice ◽  
Podocyte Injury ◽  
Mitochondrial Translocation ◽  
Maternally Expressed Gene 3

Abstract Excessive mitochondrial fission plays a key role in podocyte injury in diabetic kidney disease (DKD), and long noncoding RNAs (lncRNAs) are important in the development and progression of DKD. However, lncRNA regulation of mitochondrial fission in podocytes is poorly understood. Here, we studied lncRNA maternally expressed gene 3 (Meg3) in mitochondrial fission in vivo and in vitro using human podocytes and Meg3 podocyte-specific knockdown mice. Expression of lncRNA Meg3 in STZ-induced diabetic mice was higher, and correlated with the number of podocytes. Excessive mitochondrial fission of podocytes and renal histopathological and physiological parameters were improved in podocyte-specific Meg3 knockdown diabetic mice. Elongated mitochondria with attenuated podocyte damage, as well as mitochondrial translocation of dynamin-related protein 1 (Drp1), were decreased in Meg3 knockout podocytes. By contrast, increased fragmented mitochondria, podocyte injury, and Drp1 expression and phosphorylation were observed in lncRNA Meg3-overexpressing podocytes. Treatment with Mdivi1 significantly blunted more fragmented mitochondria and reduced podocyte injury in lncRNA Meg3-overexpressing podocytes. Finally, fragmented mitochondria and Drp1 mitochondrial translocation induced by high glucose were reduced following treatment with Mdivi1. Our data show that expression of Meg3 in podocytes in both human cells and diabetic mice was higher, which regulates mitochondrial fission and contributes to podocyte injury through increased Drp1 and its translocation to mitochondria.

scholarly journals The Attenuation of Moutan Cortex on Oxidative Stress for Renal Injury in AGEs-Induced Mesangial Cell Dysfunction and Streptozotocin-Induced Diabetic Nephropathy Rats

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Minghua Zhang ◽  
Liang Feng ◽  
Junfei Gu ◽  
Liang Ma ◽  
Dong Qin ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Diabetic Nephropathy ◽  
Transforming Growth Factor Beta ◽  
High Glucose ◽  
Transforming Growth Factor ◽  
Mesangial Cell ◽  
Cell Dysfunction ◽  
Moutan Cortex

Oxidative stress (OS) has been regarded as one of the major pathogeneses of diabetic nephropathy (DN) through damaging kidney which is associated with renal cells dysfunction. The aim of this study was to investigate whether Moutan Cortex (MC) could protect kidney function against oxidative stressin vitroorin vivo. The compounds in MC extract were analyzed by HPLC-ESI-MS. High-glucose-fat diet and STZ (30 mg kg−1) were used to induce DN rats model, while 200 μg mL−1AGEs were for HBZY-1 mesangial cell damage. The treatment with MC could significantly increase the activity of SOD, glutathione peroxidase (GSH-PX), and catalase (CAT). However, lipid peroxidation malondialdehyde (MDA) was reduced markedlyin vitroorin vivo. Furthermore, MC decreased markedly the levels of blood glucose, serum creatinine, and urine protein in DN rats. Immunohistochemical assay showed that MC downregulated significantly transforming growth factor beta 2 (TGF-β2) protein expression in renal tissue. Our data provided evidence to support this fact that MC attenuated OS in AGEs-induced mesangial cell dysfunction and also in high-glucose-fat diet and STZ-induced DN rats.

scholarly journals METTL14 aggravates podocyte injury and glomerulopathy progression through N6-methyladenosine-dependent downregulating of Sirt1

2021 ◽  
Vol 12 (10) ◽  
Author(s):  
Zhihui Lu ◽  
Hong Liu ◽  
Nana Song ◽  
Yiran Liang ◽  
Jiaming Zhu ◽  
...  
Keyword(s):  
Diabetic Nephropathy ◽  
Posttranscriptional Regulation ◽  
Kidney Diseases ◽  
Luciferase Reporter ◽  
Podocyte Injury ◽  
Glomerular Function ◽  
Apoptosis And Inflammation ◽  
Dual Luciferase Reporter Assay

AbstractPodocytes are known to play a determining role in the progression of proteinuric kidney disease. N6-methyladenosine (m6A), as the most abundant chemical modification in eukaryotic mRNA, has been reported to participate in various pathological processes. However, its role in podocyte injury remains unclear. In this study, we observed the elevated m6A RNA levels and the most upregulated METTL14 expression in kidneys of mice with adriamycin (ADR) and diabetic nephropathy. METTL14 was also evidently increased in renal biopsy samples from patients with focal segmental glomerulosclerosis (FSGS) and diabetic nephropathy and in cultured human podocytes with ADR or advanced glycation end product (AGE) treatment in vitro. Functionally, we generated mice with podocyte-specific METTL14 deletion, and identified METTL14 knockout in podocytes improved glomerular function and alleviated podocyte injury, characterized by activation of autophagy and inhibition of apoptosis and inflammation, in mice with ADR nephropathy. Similar to the results in vivo, knockdown of METTL14 facilitated autophagy and alleviated apoptosis and inflammation in podocytes under ADR or AGE condition in vitro. Mechanically, we identified METTL14 knockdown upregulated the level of Sirt1, a well-known protective deacetylase in proteinuric kidney diseases, in podocytes with ADR or AGE treatment. The results of MeRIP-qPCR and dual-luciferase reporter assay indicated METTL14 promoted Sirt1 mRNA m6A modification and degradation in injured podocytes. Our findings suggest METTL14-dependent RNA m6A modification contributes to podocyte injury through posttranscriptional regulation of Sirt1 mRNA, which provide a potential approach for the diagnosis and treatment of podocytopathies.

scholarly journals MicroRNA-27a targets Sfrp1 to induce renal fibrosis in diabetic nephropathy by activating Wnt/β-Catenin signalling

2020 ◽  
Vol 40 (6) ◽  
Author(s):  
MingJun Shi ◽  
PingPing Tian ◽  
ZhongQiang Liu ◽  
Fan Zhang ◽  
YingYing Zhang ◽  
...  
Keyword(s):  
Diabetic Nephropathy ◽  
High Glucose ◽  
Renal Fibrosis ◽  
Negative Control ◽  
Luciferase Reporter ◽  
Mrna Levels ◽  
Expression Levels ◽  
Stage Renal Disease

Abstract Diabetic nephropathy (DN) commonly causes end-stage renal disease (ESRD). Increasing evidence indicates that abnormal miRNA expression is tightly associated with chronic kidney disease (CKD). This work aimed to investigate whether miR-27a can promote the occurrence of renal fibrosis in DN by suppressing the expression of secreted frizzled-related protein 1 (Sfrp1) to activate Wnt/β-catenin signalling. Therefore, we assessed the expression levels of miR-27a, Sfrp1, Wnt signalling components, and extracellular matrix (ECM)-related molecules in vitro and in vivo. Sfrp1 was significantly down-regulated in a high-glucose environment, while miR-27a levels were markedly increased. A luciferase reporter assay confirmed that miR-27a down-regulated Sfrp1 by binding to the 3′ untranslated region directly. Further, NRK-52E cells under high-glucose conditions underwent transfection with miR-27a mimic or the corresponding negative control, miR-27a inhibitor or the corresponding negative control, si-Sfrp1, or combined miR-27a inhibitor and si-Sfrp1. Immunoblotting and immunofluorescence were performed to assess the relative expression levels of Wnt/β-catenin signalling and ECM components. The mRNA levels of Sfrp1, miR-27a, and ECM-related molecules were also detected by quantitative real-time PCR (qPCR). We found that miR-27a inhibitor inactivated Wnt/β-catenin signalling and reduced ECM deposition. Conversely, Wnt/β-catenin signalling was activated, while ECM deposition was increased after transfection with si-Sfrp1. Interestingly, miR-27a inhibitor attenuated the effects of si-Sfrp1. We concluded that miR-27a down-regulated Sfrp1 and activated Wnt/β-catenin signalling to promote renal fibrosis.

scholarly journals NQO1 Alleviates Renal Fibrosis by Inhibiting TLR4/NF-κB and TGF-β/Smad Signaling Pathway in Diabetic Nephropathy

2021 ◽  
Author(s):  
Duojun Qiu ◽  
Shan Song ◽  
Yawei Bian ◽  
Chen Yuan ◽  
wei zhang ◽  
...  
Keyword(s):  
Diabetic Nephropathy ◽  
Protein Expression ◽  
Inflammatory Cytokines ◽  
High Glucose ◽  
Renal Tubular ◽  
Tgf Β1 ◽  
Cytokines Secretion ◽  
Pro Inflammatory Cytokines

Abstract Background: Diabetic nephropathy is one of the main complications of diabetes, inflammation and fibrosis play an important role in its progress. NAD (P) H: quinone oxidoreductase 1 (NQO1) protects cells from oxidative stress and toxic quinone damage. In present study, we aimed to investigate the protective effects and underlying mechanisms of NQO1 on diabetes-induced renal inflammation and fibrosis. Methods: In vivo, adeno-associated virus serotype 9 was used to infect the kidneys of type 2 diabetes model db/db mice to overexpress NQO1. In vitro, human renal tubular epithelial cells (HK-2) transfected with NQO1 pcDNA were cultured in high glucose. The gene and protein expression were assessed by quantitative real-time PCR, western blot, immunofluorescence, and immunohistochemical staining. Mitochondrial reactive oxygen species was detected by MitoSox red. Result: Our study revealed that the expression of NQO1 was markedly down-regulated, Toll-like receptor 4 (TLR4) and TGF-β1 upregulated in vivo and in vitro under diabetic conditions. Overexpression of NQO1 suppressed pro-inflammatory cytokines secretion (IL-6, TNF-α, MCP-1), extracellular matrix (ECM) accumulation (collagen Ⅳ, Fibronectin) and epithelial-mesenchymal transition (EMT) (α-SMA, E-cadherin) in db/db mice kidney and high glucose cultured human renal tubular cells (HK-2). Furthermore, NQO1 overexpression ameliorated high glucose-induced TLR4/NF-κB and TGF-β/Smad pathway activation. Mechanistic studies demonstrated that TLR4 inhibitor (TAK-242) suppressed TLR4/NF-κB signaling pathway, pro-inflammatory cytokines secretion, EMT and ECM-related protein expression in HG-exposed HK-2 cells. In addition, we found that antioxidants NAC and tempol increased the expression of NQO1, decreased the expression of TLR4, TGF-β1, Nox1, Nox4 and ROS production in HK-2 cells cultured with high glucose. Conclusions: These above data suggest that NQO1 alleviates diabetes-induced renal inflammation and fibrosis by regulating TLR4/NF-κB and TGF-β/Smad signaling pathways.

P0989VDR/ATG3 AXIS REGULATES SLIT DIAGRAM TO TIGHT JUNCTION TRANSITION VIA P62-MEDIATED AUTOPHAGY PATHWAY IN DIABETIC NEPHROPATHY

2020 ◽  
Vol 35 (Supplement_3) ◽  
Author(s):  
Jingyi Qian ◽  
Bin Wang ◽  
Bicheng Liu
Keyword(s):  
Diabetic Nephropathy ◽  
Tight Junction ◽  
Degradation Pathway ◽  
Serum Starvation ◽  
Autophagic Flux ◽  
Vdr Gene ◽  
Podocyte Injury ◽  
Autophagy Pathway

Abstract Background and Aims Vitamin D receptor (VDR) loss, slit diagram (SD) to tight junction (TJ) transition and impaired autophagic flux contribute to podocyte injury in diabetic nephrology. This study aims to examine the effect and mechanism of VDR on autophagic flux and SD-TJ transition in diabetic nephropathy. Method Renal biopsy tissues from DN patients at stage IIa, IIb, III, IV and patients with minimal lesions were used to evaluate the expression of VDR, autophagic flux and SD-TJ transition glomeruli. In vitro, cultured podocytes were treated with serum starvation (SS), autophagic inhibitors (3-methyladenine 3-MA or chloroquine CQ) to determine the degradation pathway of TJ marker ZO-1. Meanwhile, db/db mice and STZ-induced rats were used to explore the therapeutic effect and mechanism of VDR agonist in diabetic nephropathy. Results SD-TJ transition between foot processes could be observed under electron microscopy in DN patients at all stages, whereas foot processes were separated by the filtration slit and appeared to be single cross-strands in the normal glomeruli. There was a trend of increasing expression of autophagic marker p62 and ZO-1 and the expression of p62 is positively correlated with the changes of ZO-1 in the glomeruli of DN patients. In vitro, inhibiting autophagy with 3-MA and CQ resulted in the accumulation of ZO-1 in cultured podocytes. In addition, Co-IP experiments further convinced the interaction between p62 and ZO-1, which was enhanced by the activation of autophagy. Podocytes apoptosis and the activity of caspase 3 and caspase 8 were significantly increased in the presence of 3-MA or CQ, while these effects were rescued by silencing p62. According to VDR gene expression data in GEO database, VDR expression was decreased in diabetic nephropathy patients compared with normal people. Knocking down VDR lowered the expression of atg3 and leaded to the blockage of autophagy, which could be reversed by over-expressing Atg3. Podocytes treated with high glucose resulted in the decrease of VDR and Atg3, impaired autophagic flux and aggravated podocytes injury. However, VDR agonist treatment partially reversed all the changes. In vivo, db/db mice and STZ-induced rats (DN animal models) exhibited SD-TJ transition, massive proteinuria, decreased expression of VDR and podocin and the increased accumulation of p62 and ZO-1, all of which could be partially reversed by VDR agonist. Conclusion VDR loss contributed to the impairment of autophagic flux and SD-TJ transition via down-regulation Atg3 in diabetic nephropathy. Here, we identified a new mechanism and evidence for VDR agonist to treat diabetic nephropathy.

Salvia miltiorrhiza Lipophilic Fraction Attenuates Oxidative Stress in Diabetic Nephropathy through Activation of Nuclear Factor Erythroid 2-Related Factor 2

2017 ◽  
Vol 45 (07) ◽  
pp. 1441-1457 ◽  
Author(s):  
Lin An ◽  
Mei Zhou ◽  
Faiz M. M. T. Marikar ◽  
Xue-Wen Hu ◽  
Qiu-Yun Miao ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Diabetic Nephropathy ◽  
High Glucose ◽  
Mesangial Cells ◽  
Salvia Miltiorrhiza ◽  
Heme Oxygenase 1 ◽  
Related Factor ◽  
Nuclear Factor

Diabetic nephropathy (DN) is a common cause of chronic kidney disease and end-stage renal disease, which can be triggered by oxidative stress. In this study, we investigated the renoprotective effect of the ethyl acetate extract of Salvia miltiorrhiza (EASM) on DN and examined the underlying molecular mechanism. We observed that EASM treatment attenuated metabolic abnormalities associated with hyperglycemic conditions in the experimental DN model. In streptozotocin (STZ)-induced mice, EASM treatment reduced albuminuria, improved renal function and alleviated the pathological alterations within the glomerulus. To mimic the hyperglycemic conditions in DN patients, we used high glucose (25[Formula: see text]mmol/L) media to stimulate mouse mesangial cells (MMCs), and EASM inhibited high glucose-induced reactive oxygen species. We also observed that EASM enhanced the expression of nuclear factor erythroid-2-related factor 2 (Nrf2), which mediated the anti-oxidant response, and its downstream gene heme oxygenase-1 (HO-1) and NAD(P)H quinone dehydrogenase 1 (NQO1) with concomitant decrease of expression of kelch-like ECH-associated protein 1 (keap1) both in vitro and in vivo. Taken together, these results suggest that EASM alleviates the progression of DN and this might be associated with activation of Nrf2.

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