scholarly journals FBW7 Regulates the Autophagy Signal in Mesangial Cells Induced by High Glucose

2019 ◽  
Vol 2019 ◽  
pp. 1-9
Author(s):  
Chenlin Gao ◽  
Fang Fan ◽  
Jiao Chen ◽  
Yang Long ◽  
Shi Tang ◽  
...  
Keyword(s):  
Diabetic Nephropathy ◽  
Inflammatory Cytokines ◽  
High Glucose ◽  
Mesangial Cells ◽  
Negative Regulator ◽  
Inflammatory Factors ◽  
Gene Overexpression ◽  
F Box Protein ◽  
The Relationship

Aims. Abnormal regulation of autophagy participates in the development of diabetic nephropathy. mTOR is the most common negative regulator of the autophagy signaling pathway. FBW7 constitutes the SCF (Skp1–Cullin1–F-box protein) recognition subunit of E3 ubiquitin ligase, and mTOR is a substrate of FBW7 that can be modified by ubiquitination and be degraded via proteasomes. In this study, we explored the relationship between FBW7 and autophagy and examined the effects of FBW7 on the occurrence of diabetic nephropathy in vitro.Materials and Methods. We cultured mesangial cells induced by high glucose in vitro and used rapamycin as a specific mTOR inhibitor, performed FBW7 gene overexpression, and detected the expression of autophagy signal and inflammatory factors by WB, ELISA, RT-PCR, and immunofluorescence.Results. High glucose can downregulate the expression of FBW7 and activate mTOR signal, which leads to diminished autophagy in renal mesangial cells, as well as renal inflammatory cytokines and fibrotic factors. RAPA, as a specifically inhibitor of mTOR, can decrease inflammatory cytokines and fibrotic factors by inhibiting mTOR. Moreover, FBW7 gene overexpression can increase autophagy by inhibiting mTOR signal; at the same time, the inflammatory cytokines and fibrotic factors were decreased in mesangial cells.Conclusions. FBW7 was decreased in renal mesangial cells induced by high glucose, and FBW7 gene overexpression can increase autophagy by inhibiting mTOR signaling and ameliorate inflammation and fibrosis.

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 Metformin Regulating miR-34a Pathway to Inhibit Egr1 in Rat Mesangial Cells Cultured with High Glucose

2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
Can Wu ◽  
Ningning Qin ◽  
Huiwen Ren ◽  
Min Yang ◽  
Shuang Liu ◽  
...  
Keyword(s):  
Western Blot ◽  
Inflammatory Cytokines ◽  
High Glucose ◽  
Real Time Pcr ◽  
Small Interfering Rna ◽  
Mesangial Cells ◽  
Inflammatory Factors ◽  
Quantitative Real Time Pcr ◽  
Interfering Rna ◽  
Cells Cultured

Background. Activating AMPKα negatively regulates Egr1 to inhibit inflammatory cytokines in high glucose. miR-34a inhibition increases phosphorylated AMPKα through mediating SIRT1 to suppress the development of fatty liver. Aim of the Study. To clarify the function of Egr1 on the inflammation and fibrosis in high glucose-cultured MCs, as well as to explore the effects of metformin on miR-34a pathway and Egr1 expression. Methods. We transfected MCs with miR-34a inhibitor. And MCs were transfected with small interfering RNA for silencing Egr1 and SIRT1. Quantitative real-time PCR was used to assay the transcription levels of Egr1 mRNA and miR-34a. Western blot was used to test the protein. And ELISA was used to measure inflammatory factors. Results. High glucose upregulates Egr1 to aggravate the inflammation and fibrosis in MCs. miR-34a suppresses the activation of SIRT1/AMPKα and results in promoting Egr1 in high glucose-cultured MCs. Metformin attenuates high glucose-stimulated inflammation and fibrosis in MCs by regulating miR-34a-mediated SIRT1/AMPKα activity and the downstream Egr1 protein. Conclusion. We enriched the effects of miR-34a pathway regulating Egr1 in high glucose-cultured MCs. It provides a foundation for future researches considering Egr1 as a therapeutic target and a new direction for the clinical application of metformin in early DKD.

scholarly journals CircSMAD4 alleviates high glucose-induced inflammation, extracellular matrix deposition and apoptosis in mouse glomerulus mesangial cells by relieving miR-377-3p-mediated BMP7 inhibition

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Rina Wu ◽  
Zheli Niu ◽  
Guangwei Ren ◽  
Lin Ruan ◽  
Lijun Sun
Keyword(s):  
Extracellular Matrix ◽  
High Glucose ◽  
Mesangial Cells ◽  
Circular Rna ◽  
Inflammatory Factors ◽  
Luciferase Reporter ◽  
Protein Levels ◽  
Matrix Deposition

Abstract Background Diabetic nephropathy (DN) is a common complication of diabetes mellitus. Accumulating studies suggest that the deregulation of circular RNA (circRNA) is involved in DN pathogenesis. This study aimed to investigate the role of circSMAD4 in DN models. Methods Mice were treated with streptozotocin to establish DN models in vivo. Mouse glomerulus mesangial cells (SV40-MES13) were treated with high glucose to establish DN models in vitro. The expression of circSMAD4, miR-377-3p and bone morphogenetic protein 7 (BMP7) mRNA was measured by quantitative real-time PCR (qPCR). The releases of inflammatory factors were examined by ELISA. The protein levels of fibrosis-related markers, apoptosis-related markers and BMP7 were checked by western blot. Cell apoptosis was monitored by flow cytometry assay. The predicted relationship between miR-377-3p and circSMAD4 or BMP7 was validated by dual-luciferase reporter assay or pull-down assay. Results CircSMAD4 was poorly expressed in DN mice and HG-treated SV40-MES13 cells. HG induced SV40-MES13 cell inflammation, extracellular matrix (ECM) deposition and apoptosis. CircSMAD4 overexpression alleviated, while circSMAD4 knockdown aggravated HG-induced SV40-MES13 cell injuries. MiR-377-3p was targeted by circSMAD4, and miR-377-3p enrichment partly reversed the effects of circSMAD4 overexpression. BMP7 was a target of miR-377-3p, and circSMAD4 regulated BMP7 expression by targeting miR-377-3p. MiR-377-3p overexpression aggravated HG-induced injuries by suppressing BMP7. Conclusion CircSMAD4 alleviates HG-induced SV40-MES13 cell inflammation, ECM deposition and apoptosis by relieving miR-377-3p-mediated inhibition on BMP7 in DN progression.

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.

Klotho Restraining Egr1/TLR4/mTOR Axis to Reducing the Expression of Fibrosis and Inflammatory Cytokines in High Glucose Cultured Rat Mesangial Cells

2018 ◽  
Vol 127 (09) ◽  
pp. 630-640 ◽  
Author(s):  
Can Wu ◽  
Xiaoyu Ma ◽  
Yang Zhou ◽  
Yv Liu ◽  
Ying Shao ◽  
...  
Keyword(s):  
Inflammatory Cytokines ◽  
High Glucose ◽  
Mesangial Cells ◽  
Mammalian Target Of Rapamycin ◽  
Kidney Injury ◽  
Glomerular Injury ◽  
Diabetic Kidney ◽  
Function Mechanism ◽  
Age Related

AbstractAnti-aging protein Klotho is closely associated with a variety of chronic diseases and age-related diseases. And Klotho gene deficiency enhances the phosphorylation of mammalian target of rapamycin (mTOR), resulting in exacerbating streptozotocin-stimulated diabetic glomerular injury and promoting the progression of early diabetic kidney disease (DKD). However, it has not yet been elucidated that the mechanism of Klotho function on the pathogenesis of diabetic glomerular injury. What’s more, insulin represents the antilipolytic effect via the mTOR-early growth response factor 1 (Egr1) regulatory axis in mammalian organism. Valsartan reduced the high glucose-activated toll like report 4 (TLR4) expression and inflammatory cytokines via inhibiting Egr1 expression. In this study, we aim to explore the effects of Klotho on Egr1 expression and TLR4/mTOR pathways activity in high glucose cultured rat mesangial cells (RMCs) in vitro. Our study revealed that high glucose upregulated Egr1 to aggravate the inflammation and fibrosis in RMCs. And high glucose activates Egr1/TLR4/mTOR regulatory axis in MCs, indicating that one coherent feedforward loop is formed. Anti-aging protein Klotho may attenuate glomerular inflammation and fibrosis to provide protection against diabetic kidney injury via inhibiting the activity of Egr1/TLR4/mTOR regulatory axis in high glucose conditions. This study complements the function mechanism of Egr1/TLR4/mTOR regulatory axis playing in the pathogenesis of DKD, and provides a new direction and theoretical basis for anti-aging protein Klotho in DKD treatment.

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.

Heat shock protein expression in diabetic nephropathy

2008 ◽  
Vol 295 (6) ◽  
pp. F1817-F1824 ◽  
Author(s):  
Federica Barutta ◽  
Silvia Pinach ◽  
Sara Giunti ◽  
Ferdinando Vittone ◽  
Josephine M. Forbes ◽  
...  
Keyword(s):  
Diabetic Nephropathy ◽  
Heat Shock ◽  
Heat Shock Protein ◽  
High Glucose ◽  
Mesangial Cells ◽  
Hsp70 Expression ◽  
Target Cells ◽  
Cellular Stresses

Heat shock protein (HSP) HSP27, HSP60, HSP70, and HSP90 are induced by cellular stresses and play a key role in cytoprotection. Both hyperglycemia and glomerular hypertension are crucial determinants in the pathogenesis of diabetic nephropathy and impose cellular stresses on renal target cells. We studied both the expression and the phosphorylation state of HSP27, HSP60, HSP70, and HSP90 in vivo in rats made diabetic with streptozotocin and in vitro in mesangial cells and podocytes exposed to either high glucose or mechanical stretch. Diabetic and control animals were studied 4, 12, and 24 wk after the onset of diabetes. Immunohistochemical analysis revealed an overexpression of HSP25, HSP60, and HSP72 in the diabetic outer medulla, whereas no differences were seen in the glomeruli. Similarly, exposure neither to high glucose nor to stretch altered HSP expression in mesangial cells and podocytes. By contrast, the phosphorylated form of HSP27 was enhanced in the glomerular podocytes of diabetic animals, and in vitro exposure of podocytes to stretch induced HSP27 phosphorylation via a P38-dependent mechanism. In conclusion, diabetes and diabetes-related insults differentially modulate HSP27, HSP60, and HSP70 expression/phosphorylation in the glomeruli and in the medulla, and this may affect the ability of renal cells to mount an effective cytoprotective response.

scholarly journals circRNA_010383 acts as a sponge for miR-135a and its downregulated expression contributes to renal fibrosis in diabetic nephropathy

2020 ◽  
Author(s):  
Ada Admin ◽  
Fenfen Peng ◽  
Wangqiu Gong ◽  
Shuting Li ◽  
Bohui Yin ◽  
...  
Keyword(s):  
Diabetic Nephropathy ◽  
High Glucose ◽  
Renal Fibrosis ◽  
Transient Receptor Potential ◽  
Mesangial Cells ◽  
Receptor Potential ◽  
Vascular Complication ◽  
Diabetic Patients

Diabetic nephropathy (DN), a vascular complication of diabetes mellitus, is the leading cause of death in diabetic patients. The contribution of aberrantly expressed circRNAs to diabetic nephropathy <i>in vivo</i> is poorly understood. Integrated comparative circRNA microarray profiling was used to examine the expression of circRNAs in diabetic kidney of db/db mice. We found that circRNA_010383 expression was markedly downregulated in diabetic kidneys, mesangial cells and tubular epithelial cells cultured in high-glucose conditions. circRNA_010383 colocalized with microRNA-135a (miR-135a) and inhibited miR-135a function by directly binding to miR-135a. <i>In vitro,</i> the knockdown of circRNA_010383 promoted the accumulation of extracellular matrix (ECM) proteins <a></a><a>and </a>downregulated the expression of transient receptor potential cation channel, subfamily C, member (TRPC1), which is a target protein of miR-135a. Furthermore, <a></a><a>circRNA_010383 overexpression</a> effectively inhibited the high-glucose-induced accumulation of ECM and increased TRPC1 levels <i>in vitro</i>. More importantly, the kidney-target of circRNA_010383 overexpression inhibited <a></a><a>proteinuria</a> and renal fibrosis in db/db mice. Mechanistically, we identified that a loss of circRNA_010383 promoted proteinuria and renal fibrosis in DN by acting as a sponge for miRNA-135a. This study reveals that circRNA_010383 may be a novel therapeutic target for DN in the future.

scholarly journals The Role of Transcription Factor Ap1 in The Activation of Nrf2/ARE Pathway Through TET1 in Diabetic Nephropathy

2020 ◽  
Author(s):  
Yongshun Tan ◽  
Huaimin Cao ◽  
Qingfei Li ◽  
Jianjun Sun
Keyword(s):  
Transcription Factor ◽  
Diabetic Nephropathy ◽  
Renal Injury ◽  
Mesangial Cells ◽  
Diabetic Complication ◽  
Differentially Expressed ◽  
Inflammatory Factors ◽  
Enhanced Secretion ◽  
Differentially Expressed Mrna

Abstract Background: TET1 abnormal expression is related to tumorigenesis, but its role in diabetic nephropathy (DN), the most common diabetic complication, is unclear. We attempted to probe the possible mechanism of TET1 in DN.Methods: The DN rat model was established and verified by marker detection and histopathological observation. The in vitro model was established in human mesangial cells (HMCs) induced by high glucose (HG), and levels of IL-6, TNF-α, IV-C and FN were examined. The differentially expressed mRNAs were screened out by microarray analysis. The most differentially expressed mRNA (TET1) was overexpressed in DN rats and HMCs to evaluate inflammation, cell viability and apoptosis, biochemical indexes and renal injury. The upstream transcription factor of TET1 was verified, and overexpressed with/without TETE1 to access its role in inflammation and renal injury. The downstream gene and pathway were also verified.Results: TET1 was poorly expressed in DN rats and HG-HMCs. High expression of TET1 decreased biochemical indexes, and renal injury of DN rats, decreased the activity, fibrosis and inflammation of HG-HMCs. Ap1 inhibited TET1 expression, and enhanced secretion of inflammatory factors in HG-HMCs and renal injury in DN rats. TET1 overexpression inhibited the effect of Ap1 on DN. TET1 promoted the transcription of Nrf2. The Ap1/Tet1 axis mediated the Nrf2/ARE pathway activity.Conclusion: Ap1 inhibits TET1 expression and activates the Nrf2/ARE pathway in DN, thus aggravating inflammation and renal injury.

Mesangial cell-derived factors alter monocyte activation and function through inflammatory pathways: possible pathogenic role in diabetic nephropathy

2009 ◽  
Vol 297 (5) ◽  
pp. F1229-F1237 ◽  
Author(s):  
Danqing Min ◽  
J. Guy Lyons ◽  
James Bonner ◽  
Stephen M. Twigg ◽  
Dennis K. Yue ◽  
...  
Keyword(s):  
Diabetic Nephropathy ◽  
Conditioned Medium ◽  
High Glucose ◽  
Mesangial Cell ◽  
Mesangial Cells ◽  
Glomerular Mesangial Cells ◽  
Monocyte Chemoattractant Protein 1 ◽  
Tnf Α ◽  
Cell Conditioned Medium

Infiltration of macrophages to the kidney is a feature of early diabetic nephropathy. For this to happen monocytes must become activated, migrate from the circulation, and infiltrate the mesangium. This process involves degradation of extracellular matrix, a process mediated by matrix metalloproteinases (MMPs). In the present study we investigate the expression of proinflammatory cytokines TNF-α, IL-6, and MMP-9 in glomeruli of control and diabetic rodents and use an in vitro coculture system to examine whether factors secreted by mesangial cells in response to a diabetic milieu can induce monocyte MMP-9 expression and infiltration. After 8 wk of diabetes, the glomerular level of TNF-α, IL-6, and macrophage number and colocalization of MMP-9 with macrophage were increased ( P < 0.01). Coculture of THP1 monocytes and glomerular mesangial cells in 5 or 25 mM glucose increased MMP-9 (5 mM: 65% and 25 mM: 112%; P < 0.05) and conditioned media degradative activity (5 mM: 30.0% and 25 mM: 33.5%: P < 0.05). These effects were reproduced by addition of mesangial cell conditioned medium to THP1 cells. High glucose (25 mM) increased TNF-α, IL-6, and monocyte chemoattractant protein-1 in mesangial cell conditioned medium. These cytokines all increased adhesion and differentiation of THP1 cells ( P < 0.05), but only TNF-α and IL-6 increased MMP-9 expression (50- and 60-fold, respectively; P < 0.05). Our results show that mesangial cell-secreted factors increase monocyte adhesion, differentiation, MMP expression, and degradative capacity. High glucose could augment these effects by increasing mesangial cell proinflammatory cytokine secretion. This mesangial cell-monocyte interaction may be important in activating monocytes to migrate from the circulation to the kidney in the early stages of diabetic nephropathy.

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