scholarly journals CYLD Deubiquitinase Negatively Regulates High Glucose-Induced NF-κB Inflammatory Signaling in Mesangial Cells

2017 ◽  
Vol 2017 ◽  
pp. 1-9
Author(s):  
Yanhui Li ◽  
Wei Huang ◽  
Youhua Xu ◽  
Luping Zhou ◽  
Yaling Liang ◽  
...  
Keyword(s):  
High Glucose ◽  
Mesangial Cells ◽  
Pressure Control ◽  
Ubiquitin Proteasome System ◽  
Negative Regulator ◽  
Dependent Manner ◽  
Glomerular Mesangial Cells ◽  
Inflammatory Signaling ◽  
Mediated Effects ◽  
Elevated Glucose

Nuclear factor-kappa B (NF-κB) is the key part of multiple signal transduction of inflammation in the pathogenesis of diabetic nephropathy (DN). The ubiquitin-proteasome system is extensively involved in the regulation of the NF-κB pathway. Cylindromatosis (CYLD) has deubiquitinase activity and acts as a negative regulator of the NF-κB signaling pathway. However, the association between CYLD and NF-κB inflammatory signaling in DN is unclear. In the present study, mouse glomerular mesangial cells (GMCs) and rat GMCs were stimulated by elevated concentrations of glucose (10, 20, and 30 mmol/L high glucose) or mannitol as the osmotic pressure control. CYLD was overexpressed or suppressed by transfection with a CYLD expressing vector or CYLD-specific siRNA, respectively. Our data showed that high glucose significantly inhibited the protein and mRNA expression of CYLD in a dose- and time-dependent manner (both p<0.05). siRNA-mediated knockdown CYLD facilitated the high glucose-induced activation of NF-κB signaling and triggered the release of MCP-1, IL-6, and IL-8 (all p<0.05). However, these high glucose-mediated effects were blunted by overexpression of CYLD (p<0.05). The present results support the involvement of CYLD in the regulation of NF-κB inflammatory signaling induced by elevated glucose, implicating CYLD as a potential therapeutic target of DN.

scholarly journals SUMO E3 Ligase PIASy Mediates High Glucose-Induced Activation of NF-κB Inflammatory Signaling in Rat Mesangial Cells

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Wei Huang ◽  
Yaling Liang ◽  
Jianhua Dong ◽  
Luping Zhou ◽  
Chenlin Gao ◽  
...  
Keyword(s):  
High Glucose ◽  
Mesangial Cells ◽  
E3 Ligase ◽  
Time Dependent ◽  
Dependent Manner ◽  
Glomerular Mesangial Cells ◽  
Inflammatory Signaling ◽  
Potential Therapeutic Target ◽  
Sumo E3 Ligase ◽  
Signaling Components

Background. Sumoylation is extensively involved in the regulation of NF-κB signaling. PIASy, as a SUMO E3 ligase, has been proved to mediate sumoylation of IκB kinase γ (IKKγ) and contribute to the activation of NF-κB under genotoxic agent stimulation. However, the association of PIASy and NF-κB signaling in the pathogenesis of diabetic nephropathy (DN) has not been defined. Methods. Rat glomerular mesangial cells (GMCs) were stimulated by high glucose; siRNA was constructed to silence the expression of PIASy; the expression of PIASy, SUMO isoforms (SUMO1, SUMO2/3), and NF-κB signaling components was analyzed by Western blot; the interaction between IKKγ and SUMO proteins was detected by coimmunoprecipitation; and the release of inflammatory cytokines MCP-1 and IL-6 was assayed by ELISA. Results. High glucose significantly upregulated the expression of PIASy, SUMO1, and SUMO2/3 in a dose- and time-dependent manner (P<0.05), induced the phosphorylation and sumoylation of IKKγ (P<0.05), and then triggered NF-κB signaling whereas MCP-1 and IL-6 were released from GMCs (P<0.05). Moreover, these high glucose-induced effects were observably reversed by siRNA-mediated knockdown of PIASy (P<0.05). Conclusion. The SUMO E3 ligase PIASy mediates high glucose-induced activation of NF-κB inflammatory signaling, suggesting that PIASy may be a potential therapeutic target of DN.

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

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
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.

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

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.

scholarly journals Effect of Elevated Glucose on Endothelin-Induced Store-Operated and Non-Store-Operated Calcium Influx in Renal Mesangial Cells

2000 ◽  
Vol 11 (7) ◽  
pp. 1225-1235
Author(s):  
LETA K. NUTT ◽  
ROGER G. O'NEIL
Keyword(s):  
Calcium Signaling ◽  
High Glucose ◽  
Mesangial Cells ◽  
Calcium Influx ◽  
Calcium Entry ◽  
Calcium Signal ◽  
Glomerular Mesangial Cells ◽  
Glucose Levels ◽  
Elevated Glucose ◽  
Acute And Chronic Exposure

Abstract. Early diabetic nephropathy exhibits renal glomerular hyperfiltration and an increase in renal plasma flow. The hyperfiltration is a dysfunctional state that may arise from a hyperglycemic-induced hypocontractility of glomerular mesangial cells that may be associated with depressed Ca2+signaling events. The present study was designed to determine the effects of acute (minutes) and chronic (days) elevated glucose levels on endothelin-induced calcium signaling with a particular emphasis on the potential influence on stores and store-operated Ca2+influx (SOCI ; also called capacitative calcium entry) in glomerular mesangial cells. Primary cultures of rat mesangial cells were grown in either high (30 mM) or normal (5 mM) glucose-containing media and tested in the presence of either high (30 mM) or normal (5 mM) glucose levels. Intracellular calcium levels were monitored with the calcium-sensitive fluorophore fura-2 before and after treatment with either endothelin-1 (10 nM), to induce typical Ca2+signals, or the endoplasmic reticulum (ER) Ca-ATPase inhibitor thapsagargin (1 μM), to unload ER Ca2+stores. Both acute and chronic exposure to high glucose levels depressed the endothelin-induced calcium signal. However, neither release of Ca2+from stores nor SOCI were depressed by high glucose levels. In contrast, an endothelin-induced calcium entry pathway (likely receptor-operated calcium influx), separate from SOCI, was markedly depressed in the presence of both acute and chronic high glucose levels. The depressant effect of high glucose was rapidly (minutes) reversible upon returning to normal glucose levels. It is concluded that high glucose levels depress endothelin-induced calcium signaling in rat mesangial cells by inhibiting non-SOCI Ca2+entry pathways, namely the receptor-operated Ca2+influx pathway. The glucose-induced alterations in the receptor-operated calcium influx pathway may, in part, contribute to the depressed contractile state of glomerular cells during periods of hyperglycemia.

scholarly journals Trigonelline regulates Wnt/β-catenin signaling in glomerular mesangial cells under high glucose conditions

2021 ◽  
Author(s):  
Chen Chen ◽  
Yan Shi ◽  
Zhen Chen ◽  
Xiangjun Li ◽  
Bo Sun ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Flow Cytometry ◽  
High Glucose ◽  
Cell Cycle Progression ◽  
Cell Injury ◽  
Mesangial Cells ◽  
Animal Experiments ◽  
Glomerular Mesangial Cells ◽  
Glucose Levels ◽  
Elevated Glucose

Abstract Background: Trigonelline have hypoglycemic effects. In previous animal experiments, we observed that trigonelline (TRL) treat-ment attenuated metabolic abnormalities associated with hyperglycemic conditions in the experimental DN model. In streptozotocin (STZ)-induced rats, TRL treatment reduced albuminuria, lowered blood sugar, improved renal function and alleviated the pathological alterations within the glomerulus. Methods: We stimulated human mesangial cells (HMC) with high glucose (30 mmol / L) medium. HMCs were transfected with β-catenin plasmid or siRNA to investigate the effect of trigonelline on high glucose-induced excessive proliferation and apoptosis of HMCs, and to understand its mechanism of action. Cell viability was measured by MTT assay. Flow cytometry was used to detect the cell cycle. Cell apoptosis was evaluated by flow cytometry and terminal dUTP transferase nick end labeling (TUNEL) assay. Protein and mRNA expression of β-catenin, Wnt5a, TCF4, Cyclin D1, and CDK4 were detected by western blotting and RT-PCR, respectively. Results: Trigonelline inhibited cell proliferation by blocking cell-cycle progression at the G1 phase and decreased apoptosis via the Wnt/β-catenin pathway. Elevated glucose levels enhanced the expression of β-catenin, an important modulator of diabetic nephropathy, while trigonelline restored up-regulation. Conclusions: High glucose and high expression of β-catenin could lead to cell injury; however, this effect was mitigated by trigonelline via managing the canonical Wnt/β-catenin signaling pathway.

scholarly journals Inhibitor of myogenic differentiation family isoform a, a new positive regulator of fibronectin production by glomerular mesangial cells

2020 ◽  
Vol 318 (3) ◽  
pp. F673-F682
Author(s):  
Parisa Yazdizadeh Shotorbani ◽  
Sarika Chaudhari ◽  
Yu Tao ◽  
Leonidas Tsiokas ◽  
Rong Ma
Keyword(s):  
Diabetic Nephropathy ◽  
High Glucose ◽  
Protein Level ◽  
Transforming Growth Factor ◽  
Mesangial Cells ◽  
Myogenic Differentiation ◽  
Mrna Levels ◽  
Dependent Manner ◽  
Glomerular Mesangial Cells ◽  
Significant Difference

Overproduction of extracellular matrix proteins, including fibronectin by mesangial cells (MCs), contributes to diabetic nephropathy. Inhibitor of myogenic differentiation family isoform a (I-mfa) is a multifunctional cytosolic protein functioning as a transcriptional modulator or plasma channel protein regulator. However, its renal effects are unknown. The present study was conducted to determine whether I-mfa regulated fibronectin production by glomerular MCs. In human MCs, overexpression of I-mfa significantly increased fibronectin abundance. Silencing I-mfa significantly reduced the level of fibronectin mRNA and blunted transforming growth factor-β1-stimulated production of fibronectin. We further found that high glucose increased I-mfa protein content in a time course (≥48 h) and concentration (≥25 mM)-dependent manner. Although high glucose exposure increased I-mfa at the protein level, it did not significantly alter transcripts of I-mfa in MCs. Furthermore, the abundance of I-mfa protein was significantly increased in the renal cortex of rats with diabetic nephropathy. The I-mfa protein level was also elevated in the glomerulus of mice with diabetic kidney disease. However, there was no significant difference in glomerular I-mfa mRNA levels between mice with and without diabetic nephropathy. Moreover, H2O2 significantly increased I-mfa protein abundance in a dose-dependent manner in cultured human MCs. The antioxidants polyethylene glycol-catalase, ammonium pyrrolidithiocarbamate, and N-acetylcysteine significantly blocked the high glucose-induced increase of I-mfa protein. Taken together, our results suggest that I-mfa, increased by high glucose/diabetes through the production of reactive oxygen species, stimulates fibronectin production by MCs.

Platelet-activating factor and the kidney

1986 ◽  
Vol 251 (1) ◽  
pp. F1-F11 ◽  
Author(s):  
D. Schlondorff ◽  
R. Neuwirth
Keyword(s):  
De Novo ◽  
Mesangial Cells ◽  
Biological Activities ◽  
Platelet Activating Factor ◽  
Calcium Ionophore ◽  
Initial Step ◽  
Renal Physiology ◽  
Dependent Manner ◽  
Glomerular Mesangial Cells ◽  
Isolated Kidney

Platelet-activating factor (PAF) represents a group of phospholipids with the basic structure of 1-alkyl-2-acetyl-sn-glycero-3-phosphocholine. A number of different cells are capable of producing PAF in response to various stimuli. The initial step of PAF formation is activation of phospholipase A2 in a calcium-dependent manner, yielding lyso-PAF. During this step arachidonic acid is also released and can be converted to its respective cyclooxygenase and lipoxygenase products. The lyso-PAF generated is then acetylated in position 2 of the glycerol backbone by a coenzyme A (CoA)-dependent acetyltransferase. An additional pathway may exist whereby PAF is generated de novo from 1-alkyl-2-acetyl-sn-glycerol by phosphocholine transferase. PAF inactivation in cells and blood is by specific acetylhydrolases. PAF exhibits a variety of biological activities including platelet and leukocyte aggregation and activation, increased vascular permeability, respiratory distress, decreased cardiac output, and hypotension. In the kidney PAF can produce decreases in blood flow, glomerular filtration, and fluid and electrolyte excretion. Intrarenal artery injection of PAF may also result in glomerular accumulation of platelets and leukocytes and mild proteinuria. PAF increases prostaglandin formation in the isolated kidney and in cultured glomerular mesangial cells. PAF also causes contraction of mesangial cells. Upon stimulation with calcium ionophore the isolated kidney, isolated glomeruli and medullary cells, and cultured mesangial cells are capable of producing PAF. The potential role for PAF in renal physiology and pathophysiology requires further investigation that may be complicated by 1) the multiple interactions of PAF, prostaglandins, and leukotrienes and 2) the autocoid nature of PAF, which may restrict its action to its site of generation.

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