scholarly journals Lack of miRNA-17 family mediates high glucose-induced PAR-1 up-regulation in glomerular mesangial cells

Author(s):  
Zhuang-Zhuang Tang ◽  
Pan-Pan Gu ◽  
Xiao-Fei An ◽  
Ling-Shan Gou ◽  
Yao-Wu Liu

Abstract Up-regulation of thrombin receptor protease-activated receptor 1 (PAR-1) is verified to contribute to chronic kidney diseases, including diabetic nephropathy, however, the mechanisms are still unclear. In this study, we investigated the effect of PAR-1 on high glucose-induced proliferation of human glomerular mesangial cells (HMCs), and explored the mechanism of PAR-1 up-regulation from alteration of microRNAs. We found that high glucose stimulated proliferation of the mesangial cells whereas PAR-1 inhibition with vorapaxar attenuated the cell proliferation. Moreover, high glucose up-regulated PAR-1 in mRNA level and protein expression while did not affect the enzymatic activity of thrombin in HMCs after 48 h culture. Then high glucose induced PAR-1 elevation was likely due to the alteration of the transcription or post-transcriptional processing. It was found that miR-17 family members including miR-17-5p, -20a-5p, and − 93-5p were markedly decreased among the eight detected microRNAs only in high glucose-cultured HMCs, but miR-129-5p, miR-181a-5p, and miR-181b-5p were markedly decreased in both high glucose-cultured HMCs and osmotic press control compared with normal glucose culture. So miR-20a was selected to confirm the role of miR-17 family on PAR-1 up-regulation, finding that miR-20a-5p overexpression reversed the up-regulation of PAR-1 in mRNA and protein levels induced by high glucose in HMCs. In summary, our finding indicated that PAR-1 up-regulation mediated proliferation of glomerular mesangial cells induced by high glucose, and deficiency of miR-17 family resulted in PAR-1 up-regulation.

2021 ◽  
Author(s):  
Zhuang-Zhuang Tang ◽  
Pan-Pan Gu ◽  
Xiao-Fei An ◽  
Ling-Shan Gou ◽  
Yao-Wu Liu

Abstract Up-regulation of thrombin receptor protease-activated receptor 1 (PAR-1) is verified to contribute to chronic kidney diseases, including diabetic nephropathy, however, the mechanisms are still unclear. In this study, we investigated the effect of PAR-1 on high glucose-induced proliferation of human glomerular mesangial cells (HMCs), and explored the mechanism of PAR-1 up-regulation from alteration of microRNAs. We found that high glucose stimulated proliferation of the mesangial cells whereas PAR-1 inhibition with vorapaxar attenuated the cell proliferation. Moreover, high glucose up-regulated PAR-1 in mRNA level and protein expression while did not affect the enzymatic activity of thrombin in HMCs after 48 h culture. Then high glucose induced PAR-1 elevation was likely due to the alteration of the transcription or post-transcriptional processing. It was found that miR-17 family members including miR-17-5p, -20a-5p, and − 93-5p were markedly decreased among the eight detected microRNAs only in high glucose-cultured HMCs, but miR-129-5p, miR-181a-5p, and miR-181b-5p were markedly decreased in both high glucose-cultured HMCs and osmotic press control compared with normal glucose culture. So miR-20a was selected to confirm the role of miR-17 family on PAR-1 up-regulation, finding that miR-20a-5p overexpression reversed the up-regulation of PAR-1 in mRNA and protein levels induced by high glucose in HMCs. In summary, our finding indicated that PAR-1 up-regulation mediated proliferation of glomerular mesangial cells induced by high glucose, and deficiency of miR-17 family resulted in PAR-1 up-regulation.


Nutrients ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 356 ◽  
Author(s):  
Ha-Rim Kim ◽  
Seon-Young Kim

Perilla frutescens (L.) Britt. var. japonica (Hassk.) Hara (PF), is a medical herb of the Lamiaceae family. We have previously reported that the PF sprout extract (PFSE) is effective in treating hyperglycemia. However, the role of PFSE on glomerular mesangial cells (MCs) proliferation and the extracellular matrix (ECM) accumulation in a diabetic condition are still unclear. Therefore, in this study, we have investigated the role of PFSE on cell proliferation and ECM accumulation in murine glomerular MCs (MMCs), cultured under a high glucose (HG) condition. PFSE treatment attenuated HG-induced MMCs proliferation and hypertrophy. Moreover, the HG-induced ECM protein, collagen IV and fibronectin, overexpression was abolished by the PFFSE treatment. In addition, PFSE inhibited reactive oxygen species (ROS) overproduction and NOX2 and NOX4 expression in MMCs under a HG condition. Our data further revealed the involvement of mesangial cell damage in AMP-activated kinase (AMPK) activation. PFSE strongly activated AMPK in MMCs under hyperglycemic conditions. These results suggest that PFSE inhibits HG-medicated MC fibrosis through suppressing the activation of NOX2/4 and the AMPK activation mechanism. PFSE may be useful for the prevention or treatment of diabetic nephropathy.


2005 ◽  
Vol 289 (5) ◽  
pp. F1078-F1087 ◽  
Author(s):  
Helena Frecker ◽  
Snezana Munk ◽  
Hong Wang ◽  
Catharine Whiteside

In high glucose, glomerular mesangial cells (MCs) demonstrate impaired Ca2+ signaling in response to seven-transmembrane receptor stimulation. To identify the mechanism, we first postulated decreased release from intracellular stores. Intracellular Ca2+ was measured in fluo-3-loaded primary cultured rat MCs using confocal fluorescence microscopy. In high glucose (HG) 30 mM for 48 h, the 25 nM ionomycin-stimulated intracellular Ca2+ response was reduced to 82% of that observed in normal glucose (NG). In NG 5.6 mM, Ca2+ responses to endothelin (ET)-1 and platelet-derived growth factor (PDGF) were unchanged in cells cultured in 50 nM Ca2+ vs. 1.8 mM Ca2+. Depletion of intracellular Ca2+ stores with thapsigargin eliminated ET-1-stimulated Ca2+ responses. Incubation in 30 mM glucose (HG) for 48 h or stimulation with phorbol myristate acetate (PMA) for 10 min eliminated the Ca2+ response to ET-1 but had no effect on the PDGF response. Downregulation of protein kinase C (PKC) with 24-h PMA or inhibition with Gö6976 in HG normalized the Ca2+ response to ET-1. Because ET-1 and PDGF stimulate Ca2+ signaling through different phospholipase C pathways, we hypothesized that, in HG, PKC selectively phosphorylates and inhibits PLC-β3. Using confocal immunofluorescence imaging, in NG, a 1.6- to 1.7-fold increase in PLC-β3 Ser1105 phosphorylation was observed following PMA or ET-1 stimulation for 10 min. In HG, immunofluorescent imaging and immunoblotting showed increased PLC-β3 phosphorylation, without change in total PLC-β3, which was reversed with 24-h PMA or Gö6976. We conclude that reduced Ca2+ signaling in HG cannot be explained by reduced Ca2+ stores but is due to conventional PKC-dependent phosphorylation and inactivation of PLC-β3.


2001 ◽  
Vol 281 (4) ◽  
pp. F613-F619 ◽  
Author(s):  
Anoop Kumar ◽  
Karen S. Hawkins ◽  
Meredith A. Hannan ◽  
Michael B. Ganz

Changes in expression and activity of protein kinase C (PKC) isoforms and early transcription factors may account for alterations in cell behavior seen in diabetes. We studied the expression of PKC-βIin rat glomerular mesangial cells (MCs) cultured in normal or high glucose and compared it with the temporal and spatial expression of dimeric transcription factor (NF-κB) p50 and p65. The results show that in unstimulated cells PKC-βIand NF-κB p50 are distributed in the cytosol and, on stimulation, their distribution is perinuclear and they are localized to the membrane. Serum-starved MCs cultured in high-glucose medium exhibit a predominantly cytosolic localization of PKC-βIand both p50 and p65 NF-κB. However, phorbol 12-myristate 13-acetate (PMA) stimulation of cells grown in the presence of high glucose resulted in membrane translocation of PKC-βIthat was associated with nuclear translocation of NF-κB p65, but not NF-κB p50. Moreover, the translocation to the nucleus for NF-κB p65 was significantly higher in MCs exposed to high glucose compared with those exposed to normal glucose. These observations indicate that the NF-κB p65, but not NF-κB p50, expression and translocation pattern mirrors that of PKC-βI, which may be one important pathway by which signaling is enhanced in the high-glucose state.


1995 ◽  
Vol 269 (3) ◽  
pp. F389-F397 ◽  
Author(s):  
E. E. Seal ◽  
D. C. Eaton ◽  
L. M. Gomez ◽  
H. Ma ◽  
B. N. Ling

Abnormal cellular ion homeostasis is a well-recognized component of diabetic glomerular disease. In cultured rat glomerular mesangial cells, we have previously shown that insulin regulates Ca(2+)-dependent activation of 4-pS Cl- channels and 27-pS nonselective cation channels (NSCC) by angiotensin II (ANG II). To assess whether extracellular glucose also affects mesangial ion channels, we applied patch-clamp techniques to cells incubated in constant insulin (100 mU/ml) and either "normal" (5 mM) or "high" (30 mM) glucose for 1 wk. In normal glucose, 100 nM ANG II increased Cl- and NSCC activity by > 16-fold and > 60-fold, respectivley. Direct release of intracellular Ca2+ ([Ca2+]i) stores (0.25 microM thapsigargin) mimicked ANG II-induced channel stimulation. In high glucose, Cl- and NSCC stimulation by ANG II was attenuated (< 7-fold), whereas channel activation by thapsigargin was unaffected. Protein kinase C (PKC) inhibition (30-min exposure to 0.5 microM calphostin) or downregulation (24-h exposure to 0.1 microM 4 beta-phorbol 12-myristate 13-acetate), but not aldose reductase inhibition (0.5 mM sorbinil), restored channel responsiveness to ANG II despite high glucose. Channel responsiveness was also restored if mesangial cells were coincubated in both high glucose and 500 microM myo-inositol. Acute exposure to a synthetic diacylglycerol (100 microM 1-oleoyl-2-acetyl glycerol) reestablished channel unresponsiveness to ANG II. We conclude the following in rat mesangial cell cultures: 1) Activation of Ca(2+)-dependent Cl- and NSCCs by ANG II is reduced by high extracellular glucose.(ABSTRACT TRUNCATED AT 250 WORDS)


2018 ◽  
Vol 49 (5) ◽  
pp. 1747-1754 ◽  
Author(s):  
Deng Yunlei ◽  
Fan  Qiuling ◽  
Wang Xu ◽  
Zhao Qianwen ◽  
Cao Xu ◽  
...  

Background/Aims: Diabetic nephropathy is the one of the most serious microvascular complications of diabetes mellitus, and “metabolic memory” plays a vital role in the development of diabetic complications. To investigate the effect of epigenetics on metabolic memory, we analyzed the impact of transient high-glucose stimulation on the secretion of inflammatory factors from rat glomerular mesangial cells. Methods: Rat glomerular mesangial cells (HBZY-1) were divided into three groups: high-glucose group (25 mM glucose), hypertonic group (5.5 mM glucose+19.5 mM mannitol), and normal-glucose control group (5.5 mM glucose). Mesangial cells were cultured in high-glucose, hypertonic, and normal-glucose media for 24 h and transitioned to normal-glucose culture for 24, 48, and 72 h. Then, protein, mRNA, and supernatants were harvested. The expression of monomethylated H3K4 was determined by western blot analysis, and the expression of the NF-κB subunit p65 and histone methyltransferase set7/9 was determined by quantitative real-time PCR. The expression of monocyte chemoattractant protein 1 (MCP-1) and vascular cell adhesion molecule 1 (VCAM-1) was detected by an enzyme-linked immunosorbent assay. Results: Compared with the control group, H3K4me1 expression was upregulated after transient high-glucose stimulation, gradually downregulated in the following 48 h (P < 0.05), and reached the level of the control group at 72 h (P > 0.05). The expression of set7/9 was increased after 24 h of high-glucose stimulation and the following 24 h and 48 h (P < 0.05); it then returned to the level of the control group at 72 h. Compared with the control group, the increased expression of p65, VCAM-1, and MCP-1 was sustained for at least 72 h in the high-glucose group. Conclusion: Transient high-glucose stimulation can induce the persistent secretion of inflammatory factors from rat glomerular mesangial cells via histone modification.


Endocrinology ◽  
2006 ◽  
Vol 147 (1) ◽  
pp. 222-231 ◽  
Author(s):  
Howard J. Goldberg ◽  
Catharine I. Whiteside ◽  
Gerald W. Hart ◽  
I. George Fantus

Metabolic flux through the hexosamine biosynthetic pathway (HBP) is increased in the presence of high glucose (HG) and potentially stimulates the expression of genes associated with the development of diabetic nephropathy. A number of synthetic processes are coupled to the HBP, including enzymatic intracellular O-glycosylation (O-GlcNAcylation), the addition of single O-linked N-acetylglucosamine monosaccharides to serine or threonine residues. Despite much data linking flow through the HBP and gene expression, the exact contribution of O-GlcNAcylation to HG-stimulated gene expression remains unclear. In glomerular mesangial cells, HG-stimulated plasminogen activator inhibitor-1 (PAI-1) gene expression requires the HBP and the transcription factor, Sp1. In this study, the specific role of O-GlcNAcylation in HG-induced PAI-1 expression was tested by limiting this modification with a dominant-negative O-linked N-acetylglucosamine transferase, by overexpression of neutral β-N-acetylglucosaminidase, and by knockdown of O-linked β-N-acetylglucosamine transferase expression by RNA interference. Decreasing O-GlcNAcylation by these means inhibited the ability of HG to increase endogenous PAI-1 mRNA and protein levels, the activity of a PAI-1 promoter-luciferase reporter gene, and Sp1 transcriptional activation. Conversely, treatment with the β-N-acetylglucosaminidase inhibitor, O-(2-acetamido-2-deoxy-d-glucopyranosylidene)amino-N-phenylcarbamate, in the presence of normal glucose increased Sp1 O-GlcNAcylation and PAI-1 mRNA and protein levels. These findings demonstrate for the first time that among the pathways served by the HBP, O-GlcNAcylation, is obligatory for HG-induced PAI-1 gene expression and Sp1 transcriptional activation in mesangial cells.


2015 ◽  
Vol 36 (6) ◽  
pp. 2093-2107 ◽  
Author(s):  
Dan Wang ◽  
Mei-Ping Guan ◽  
Zong-Ji Zheng ◽  
Wen-Qi Li ◽  
Fu-Ping Lyv ◽  
...  

Backgroud: Diabetic nephropathy is one of the most frequent causes of end-stage renal disease and is associated with proliferation of glomerular mesangial cells (MCs) and excessive production of the extracellular matrix (ECM). Several studies have shown that early growth response factor 1 (Egr1) plays a key role in renal fibrosis by regulating the expression of genes encoding ECM components. However, whether Egr1 also contributes to diabetic nephropathy is unclear. Methods: In the present study, we compared the expression of Egr1 in kidneys from OLETF rats with spontaneous type 2 diabetes and healthy LETO rats. We also examined whether high glucose and TGF-β1 signaling up-regulated Egr1 expression in cultured MCs, and whether Egr1 expression influenced MC proliferation and expression of ECM genes. Results: We found that higher expression of Egr1 and TGF-β1, at both the mRNA and protein levels, the kidneys from OLETF rats vs. LETO rats. High glucose or TGF-β1 signaling rapidly up-regulated expression of Egr1 mRNA and protein in cultured MCs. Overexpressing Egr1 in MCs by transfection with M61-Egr1 plasmid or treatment with high glucose up-regulated expression of fibronectin, type IV collagen and TGF-β1, and promoted MC proliferation. Conversely, siRNA-mediated silencing of Egr1 expression down-regulated these genes and inhibited MC proliferation. Chromatin immunoprecipitation (ChIP) assays revealed that Egr1 bound to the TGF-β1 promoter. Conclusion: Our results provide strong evidence that Egr1 contributes to diabetic nephropathy by enhancing MC proliferation and ECM production, in part by interacting with TGF-β1.


2014 ◽  
Vol 306 (9) ◽  
pp. F1069-F1080 ◽  
Author(s):  
Sarika Chaudhari ◽  
Peiwen Wu ◽  
Yanxia Wang ◽  
Yanfeng Ding ◽  
Joseph Yuan ◽  
...  

The present study was conducted to determine whether and how store-operated Ca2+ entry (SOCE) in glomerular mesangial cells (MCs) was altered by high glucose (HG) and diabetes. Human MCs were treated with either normal glucose or HG for different time periods. Cyclopiazonic acid-induced SOCE was significantly greater in the MCs with 7-day HG treatment and the response was completely abolished by GSK-7975A, a selective inhibitor of store-operated Ca2+ channels. Similarly, the inositol 1,4,5-trisphosphate-induced store-operated Ca2+ currents were significantly enhanced in the MCs treated with HG for 7 days, and the enhanced response was abolished by both GSK-7975A and La3+. In contrast, receptor-operated Ca2+ entry in MCs was significantly reduced by HG treatment. Western blotting showed that HG increased the expression levels of STIM1 and Orai1 in cultured MCs. A significant HG effect occurred at a concentration as low as 10 mM, but required a minimum of 7 days. The HG effect in cultured MCs was recapitulated in renal glomeruli/cortex of both type I and II diabetic rats. Furthermore, quantitative real-time RT-PCR revealed that a 6-day HG treatment significantly increased the mRNA expression level of STIM1. However, the expressions of STIM2 and Orai1 transcripts were not affected by HG. Taken together, these results suggest that HG/diabetes enhanced SOCE in MCs by increasing STIM1/Orai1 protein expressions. HG upregulates STIM1 by promoting its transcription but increases Orai1 protein through a posttranscriptional mechanism.


2014 ◽  
Vol 25 (16) ◽  
pp. 2342-2350 ◽  
Author(s):  
Charles G. Miller ◽  
Ambra Pozzi ◽  
Roy Zent ◽  
Jean E. Schwarzbauer

The filtration unit of the kidney is the glomerulus, a capillary network supported by mesangial cells and extracellular matrix (ECM). Glomerular function is compromised in diabetic nephropathy (DN) by uncontrolled buildup of ECM, especially type IV collagen, which progressively occludes the capillaries. Increased levels of the ECM protein fibronectin (FN) are also present; however, its role in DN is unknown. Mesangial cells cultured under high glucose conditions provide a model system for studying the effect of elevated glucose on deposition of FN and collagen IV. Imaging of mesangial cell cultures and analysis of detergent-insoluble matrix show that, under high glucose conditions, mesangial cells assembled significantly more FN matrix, independent of FN protein levels. High glucose conditions induced protein kinase C–dependent β1 integrin activation, and FN assembly in normal glucose was increased by stimulation of integrin activity with Mn2+. Collagen IV incorporation into the matrix was also increased under high glucose conditions and colocalized with FN fibrils. An inhibitor of FN matrix assembly prevented collagen IV deposition, demonstrating dependence of collagen IV on FN matrix. We conclude that high glucose induces FN assembly, which contributes to collagen IV accumulation. Enhanced assembly of FN might facilitate dysregulated ECM accumulation in DN.


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