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

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.

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RIPK2-Mediated Autophagy and Negatively Regulated ROS-NLRP3 Inflammasome Signaling in GMCs Stimulated with High Glucose

Mediators of Inflammation ◽

10.1155/2019/6207563 ◽

2019 ◽

Vol 2019 ◽

pp. 1-13 ◽

Cited By ~ 1

Author(s):

Chenlin Gao ◽

Jiao Chen ◽

Fang Fan ◽

Yang Long ◽

Shi Tang ◽

...

Keyword(s):

Nlrp3 Inflammasome ◽

High Glucose ◽

Mesangial Cells ◽

Vital Role ◽

Dependent Manner ◽

Glomerular Mesangial Cells ◽

Interacting Protein ◽

High Glucose Group ◽

Glucose Group

Background. Hyperglycemia plays a vital role in diabetic nephropathy (DN); autophagy and its potential upregulator receptor-interacting protein kinase 2 (RIPK2) are associated with ROS, which play a potential role in regulating NLRP3, and may be involved in inflammation in DN. Aim. In this study, we aimed to explore the mechanisms mediated by RIPK2 in autophagy and the relationship with ROS-NLRP3 of DN, by investigating the levels of RIPK2 and autophagy in glomerular mesangial cells (GMCs) stimulated with high glucose. Material and Methods. GMCs were divided into the following groups: normal group (NC), high glucose group (HG), and RIPK2 siRNA group. RIPK2, LC3, caspase1, and IL-1β levels were measured by western blotting and RT-PCR. Autophagosomes were measured by GFP-RFP-LC3; ROS were detected by DCFH-DA. Results. High glucose upregulated RIPK2 and LC3 in GMCs during short periods (0-12 h) (p<0.01), while RIPK2 and LC3 were significantly downregulated in the long term (12-72 h) (p<0.01); these changes were positively correlated with glucose concentration (p<0.01). In addition, levels of ROS, caspase1, and IL-1β increased in a time- and dose-dependent manner in the high glucose group, even with an increased expression of LC3 (p<0.01). However, LC3 expression decreased in the siRIPK2 group, while levels of ROS, caspase1, and IL-1β increased (p<0.01). Conclusions. Autophagy was activated by high glucose at short time periods but was inhibited in the long term, demonstrating a dual role for high glucose in autophagy of GMCs. RIPK2 regulates ROS-NLRP3 inflammasome signaling through autophagy and may be involved in the pathogenesis of DN.

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Sweet Taste Receptors Mediated ROS-NLRP3 Inflammasome Signaling Activation: Implications for Diabetic Nephropathy

Journal of Diabetes Research ◽

10.1155/2018/7078214 ◽

2018 ◽

Vol 2018 ◽

pp. 1-15 ◽

Cited By ~ 9

Author(s):

Luping Zhou ◽

Wei Huang ◽

Youhua Xu ◽

Chenlin Gao ◽

Ting Zhang ◽

...

Keyword(s):

Diabetic Nephropathy ◽

Nlrp3 Inflammasome ◽

High Glucose ◽

Sweet Taste ◽

Taste Receptors ◽

Glomerular Mesangial Cells ◽

Sweet Taste Receptors ◽

Signaling Activation

Previous studies demonstrated that ROS-NLRP3 inflammasome signaling activation was involved in the pathogenesis of diabetic nephropathy (DN). Recent research has shown that sweet taste receptors (STRs) are important sentinels of innate immunity. Whether high glucose primes ROS-NLRP3 inflammasome signaling via STRs is unclear. In this study, diabetic mouse model was induced by streptozotocin (STZ) in vivo; mouse glomerular mesangial cells (GMCs) and human proximal tubular cells were stimulated by high glucose (10, 20, and 30 mmol/L) in vitro; STR inhibitor lactisole was used as an intervention reagent to evaluate the role and mechanism of the STRs in the pathogenesis of DN. Our results showed that the expression of STRs and associated signaling components (Gα-gustducin, PLCβ2, and TRPM5) was obviously downregulated under the condition of diabetes in vivo and in vitro. Furthermore, lactisole significantly mitigated the production of intracellular ROS and reversed the high glucose-induced decrease of Ca2+ and the activation of NLRP3 inflammasome signaling in vitro (p<0.05). These combined results support the hypothesis that STRs could be involved in the activation of ROS-NLRP3 inflammasome signaling in the pathogenesis of DN, suggesting that STRs may act as new therapeutic targets of DN.

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Suppressions of chronic glomerular injuries and TGF-β1 production by HGF in attenuation of murine diabetic nephropathy

AJP Renal Physiology ◽

10.1152/ajprenal.00199.2003 ◽

2004 ◽

Vol 286 (1) ◽

pp. F134-F143 ◽

Cited By ~ 69

Author(s):

Shinya Mizuno ◽

Toshikazu Nakamura

Keyword(s):

Diabetic Nephropathy ◽

Growth Factor ◽

Renal Dysfunction ◽

Transforming Growth Factor ◽

Mesangial Cells ◽

Renal Diseases ◽

Glomerular Mesangial Cells ◽

Diabetic Mice

Diabetic nephropathy is now the leading cause of end-stage renal diseases, and glomerular sclerotic injury is an initial event that provokes renal dysfunction during processes of diabetes-linked kidney disease. Growing evidence shows that transforming growth factor-β1 (TGF-β1) plays a key role in this process, especially in eliciting hypertrophy and matrix overaccumulation. Thus it is important to find a ligand system to antagonize the TGF-β1-mediated pathogenesis under high-glucose conditions. Herein, we provide evidence that hepatocyte growth factor (HGF) targets mesangial cells, suppresses TGF-β1 production, and minimizes glomerular sclerotic changes, using streptozotocin-induced diabetic mice. In our murine model, glomerular sclerogenesis (such as tuft area expansion and collagen deposition) progressed between 6 and 10 wk after the induction of hyperglycemia, during a natural course of diabetic disease. Glomerular HGF expression levels in the diabetic kidney transiently increased but then declined below a basal level, with manifestation of glomerular sclerogenesis. When anti-HGF IgG was injected into mice for 2 wk (i.e., from weeks 4 to 6 after onset of hyperglycemia), these glomerular changes were significantly aggravated. When recombinant HGF was injected into the mice for 4 wk (i.e., between 6 and 10 wk following streptozotocin treatment), the progression of glomerular hypertrophy and sclerosis was almost completely inhibited, even though glucose levels remained unchanged (>500 mg/dl). Even more important, HGF repressed TGF-β1 production in glomerular mesangial cells even under hyperglycemic conditions both in vitro and in vivo. Consequently, not only albuminuria but also tubulointerstitial fibrogenesis were attenuated by HGF. Overall, HGF therapy inhibited the onset of renal dysfunction in the diabetic mice. On the basis of these findings, we wish to emphasize that HGF plays physiological and therapeutic roles in blocking renal fibrogenesis during a course of diabetic nephropathy.

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Hyperoside Alleviates High Glucose-Induced Proliferation of Mesangial Cells through the Inhibition of the ERK/CREB/miRNA-34a Signaling Pathway

International Journal of Endocrinology ◽

10.1155/2020/1361924 ◽

2020 ◽

Vol 2020 ◽

pp. 1-10

Author(s):

Le Zhang ◽

Qian Dai ◽

Lanlan Hu ◽

Hua Yu ◽

Jing Qiu ◽

...

Keyword(s):

Diabetic Nephropathy ◽

Signaling Pathway ◽

High Glucose ◽

Mesangial Cells ◽

Viable Cell ◽

Underlying Mechanism ◽

Cell Counting ◽

Luciferase Reporter ◽

Dependent Manner ◽

Glomerular Mesangial Cells

Purpose. Hyperoside, a flavonoid isolated from conventional medicinal herbs, has been demonstrated to exert a significant protective effect in diabetic nephropathy. This study aimed to determine the underlying mechanisms, by which hyperoside inhibits high glucose-(HG-) induced proliferation in mouse renal mesangial cells. Methods. Mouse glomerular mesangial cells line (SV40-MES13) was used to study the inhibitory effect of hyperoside on cell proliferation induced by 30 mM glucose, which was used to simulate a diabetic condition. Viable cell count was assessed using the Cell Counting Kit-8 and by the 5-ethynyl-20-deoxyuridine incorporation assay. The underlying mechanism involving miRNA-34a was further investigated by quantitative RT-PCR and transfection with miRNA-34a agomir. The phosphorylation levels of extracellular signal-regulated kinases (ERKs) and cAMP-response element-binding protein (CREB) were measured by Western blotting. The binding region and the critical binding sites of CREB in the miRNA-34a promoter were investigated by the chromatin immunoprecipitation assay and luciferase reporter assay, respectively. Results. We found that hyperoside could significantly decrease HG-induced proliferation of SV40-MES13 cells in a dose-dependent manner, without causing obvious cell death. In addition, hyperoside inhibited the activation of ERK pathway and phosphorylation of its downstream transcriptional factor CREB, as well as the miRNA-34a expression. We further confirmed that CREB-mediated regulation of miRNA-34a is dependent on the direct binding to specific sites in the promoter region of miRNA-34a. Conclusion. Our cumulative results suggested that hyperoside inhibits the proliferation of SV40-MES13 cells through the suppression of the ERK/CREB/miRNA-34a signaling pathway, which provides new insight to the current investigation on therapeutic strategies for diabetic nephropathy.

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Exosomes from high glucose–treated macrophages activate glomerular mesangial cells via TGF‐β1/Smad3 pathway in vivo and in vitro

The FASEB Journal ◽

10.1096/fj.201802427rrr ◽

2019 ◽

Vol 33 (8) ◽

pp. 9279-9290 ◽

Cited By ~ 11

Author(s):

Qi‐Jin Zhu ◽

Mei Zhu ◽

Xing‐Xin Xu ◽

Xiao‐Ming Meng ◽

Yong‐Gui Wu

Keyword(s):

High Glucose ◽

Mesangial Cells ◽

Glomerular Mesangial Cells ◽

Tgf Β1

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

The American Journal of Chinese Medicine ◽

10.1142/s0192415x17500781 ◽

2017 ◽

Vol 45 (07) ◽

pp. 1441-1457 ◽

Cited By ~ 8

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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Heat shock protein expression in diabetic nephropathy

AJP Renal Physiology ◽

10.1152/ajprenal.90234.2008 ◽

2008 ◽

Vol 295 (6) ◽

pp. F1817-F1824 ◽

Cited By ~ 30

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.

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

10.2337/figshare.13177115.v1 ◽

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 in vivo 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. In vitro, 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 in vitro. 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.

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Tangshen Formula Attenuates Diabetic Kidney Injury by Imparting Anti-pyroptotic Effects via the TXNIP-NLRP3-GSDMD Axis

Frontiers in Pharmacology ◽

10.3389/fphar.2020.623489 ◽

2021 ◽

Vol 11 ◽

Author(s):

Nan Li ◽

Tingting Zhao ◽

Yongtong Cao ◽

Haojun Zhang ◽

Liang Peng ◽

...

Keyword(s):

Nlrp3 Inflammasome ◽

Kidney Injury ◽

Inflammasome Activation ◽

Dependent Manner ◽

Protective Effects ◽

Interacting Protein ◽

Diabetic Kidney ◽

Tangshen Formula

We previously reported that Tangshen formula (TSF), a Chinese herbal medicine for diabetic kidney disease (DKD) therapy, imparts renal protective effects. However, the underlying mechanisms of these effects remain unclear. Pyroptosis is a form of programmed cell death that can be triggered by the NLRP3 inflammasome. Recently, the association between the pyroptosis of renal resident cells and DKD was established, but with limited evidence. This study aimed to investigate whether the renal protective effects of TSF are related to its anti-pyroptotic effect. DKD rats established by right uninephrectomy plus a single intraperitoneal injection of STZ and HK-2 cells stimulated by AGEs were used. In vivo, TSF reduced the 24 h urine protein (24 h UP) of DKD rats and alleviated renal pathological changes. Meanwhile, the increased expression of pyroptotic executor (GSDMD) and NLRP3 inflammasome pathway molecules (NLRP3, caspase-1, and IL-1β) located in the tubules of DKD rats were downregulated with TSF treatment. In vitro, we confirmed the existence of pyroptosis in AGE-stimulated HK-2 cells and the activation of the NLRP3 inflammasome. TSF reduced pyroptosis and NLRP3 inflammasome activation in a dosage-dependent manner. Then, we used nigericin to determine that TSF imparts anti-pyroptotic effects by inhibiting the NLRP3 inflammasome. Finally, we found that TSF reduces reactive oxygen species (ROS) production and thioredoxin-interacting protein (TXNIP) expression in AGE-stimulated HK-2 cells. More importantly, TSF decreased the colocalization of TXNIP and NLRP3, indicating that ROS-TXNIP may be the target of TSF. In summary, the anti-pyroptotic effect via the TXNIP-NLRP3-GSDMD axis may be an important mechanism of TSF for DKD therapy.

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Tongxinluo Inhibits Renal Fibrosis in Diabetic Nephropathy: Involvement of the Suppression of Intercellular Transfer of TGF-β1-Containing Exosomes from GECs to GMCs

The American Journal of Chinese Medicine ◽

10.1142/s0192415x17500586 ◽

2017 ◽

Vol 45 (05) ◽

pp. 1075-1092 ◽

Cited By ~ 10

Author(s):

Xiao-Ming Wu ◽

Yan-Bin Gao ◽

Li-Ping Xu ◽

Da-Wei Zou ◽

Zhi-Yao Zhu ◽

...

Keyword(s):

Diabetic Nephropathy ◽

Mesangial Cells ◽

Glomerular Mesangial Cells ◽

Intercellular Transfer ◽

Beneficial Effects ◽

Renal Structure ◽

And Function

Glomerular mesangial cells (GMCs) activation is implicated in the pathogenesis of diabetic nephropathy (DN). Our previous study revealed that high glucose (HG)-treated glomerular endothelial cells (GECs) produce an increased number of TGF-[Formula: see text]1-containing exosomes to activate GMCs through the TGF-[Formula: see text]1/Smad3 signaling pathway. We also identified that Tongxinluo (TXL), a traditional Chinese medicine, has beneficial effects on the treatment of DN in DN patients and type 2 diabetic mice. However, it remained elusive whether TXL could ameliorate renal structure and function through suppression of intercellular transfer of TGF-[Formula: see text]1-containing exosomes from GECs to GMCs. In this study, we demonstrate that TXL can inhibit the secretion of TGF-[Formula: see text]1-containing exosomes from HG-treated GECs. Furthermore, exosomes produced by HG induced-GECs treated with TXL cannot trigger GMC activation, proliferation and extracellular matrix (ECM) overproduction both in vitro and in vivo. These results suggest that TXL can prevent the transfer of TGF-[Formula: see text]1 from GECs to GMCs via exosomes, which may be one of the mechanisms of TXL in the treatment of DN.

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