Effect of high glucose on gene expression in mesangial cells: upregulation of the thiol pathway is an adaptational response

2004 ◽  
Vol 17 (3) ◽  
pp. 271-282 ◽  
Author(s):  
Jolean Morrison ◽  
Kristen Knoll ◽  
Martin J. Hessner ◽  
Mingyu Liang

Pathological alterations in glomerular mesangial cells play a critical role in the development of diabetic nephropathy, the leading cause of end-stage renal disease. Molecular mechanisms mediating such alterations, however, remain to be fully understood. The present study first examined the effect of high glucose on the mRNA expression profile in rat mesangial cells using cDNA microarray. Based on variation-weighted criteria and with a false discovery rate of 4.3%, 459 of 17,664 cDNA elements examined were found to be upregulated and 151 downregulated by exposure to 25 mM d-glucose for 5 days. A large number of differentially expressed genes belonged to several functional categories, indicating high glucose had a profound effect on mesangial cell proliferation, protein synthesis, energy metabolism, and, somewhat unexpectedly, protein sorting and the cytoskeleton. Interestingly, several thiol antioxidative genes (glutathione peroxidase 1, peroxiredoxin 6, and thioredoxin 2) were found by microarray and confirmed by real-time PCR to be upregulated by high glucose. These changes suggested that the oxidative stress known to be induced in mesangial cells by high glucose might be buffered by upregulation of the thiol antioxidative pathway. Upregulation of thiol antioxidative genes also occurred in high-glucose-treated human mesangial cells and in glomeruli isolated from rats after 1 wk of streptozotocin-induced diabetes, but not in human proximal tubule cells. High glucose slightly increased lipid peroxidation and decreased the amount of reduced thiols in rat and human mesangial cells. Disruption of the thiol antioxidative pathway by two different thiol-oxidizing agents resulted in a three- to fivefold increase in high-glucose-induced lipid peroxidation. In summary, the present study provided a global view of the short-term effect of high glucose on mesangial cells at the level of mRNA expression and identified the upregulation of the thiol antioxidative pathway as an adaptational response of mesangial cells to high glucose.

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Zhuang Geng ◽  
Xiang Wang ◽  
Shiyuan Hao ◽  
Bingzi Dong ◽  
Yajing Huang ◽  
...  

Abstract Background LncRNA NNT-AS1 (NNT-AS1) has been extensively studied as the causative agent in propagation and progression of lung and bladder cancers, and cholangiocarcinoma. However, its significance in proliferation and inflammation of diabetic nephropathy is enigmatic. This study focuses on the molecular mechanisms followed by NNT-AS1 to establish diabetic nephropathy (DN) and its potential miRNA target. Methods Bioinformatics analysis to identify potential miRNA target of NNT-AS1 and smad4 transcription factor was conducted using LncBase and TargetScan, and was subsequently confirmed by luciferase reporter assay. Relative quantitative expression of NNT-AS1 in human glomerular mesangial cells (HGMCs) was detected through quantitative real-time PCR and WB analysis. Cell proliferation was detected through CCK-8 assay, whereas, ELISA was conducted to evaluate the expression of inflammatory cytokines. Following this, relative expression of miR-214-5p and smad4 were confirmed through qRT-PCR and western blot analysis. Results Results from the experiments manifested up-regulated levels of NNT-AS1 and smad4 in the blood samples of DN patients as well as in HGMCs, whereas, downregulated levels of miR-214-5p were measured in the HGMCs suggesting the negative correlation between NNT-AS1 and miR-214-5p. Potential binding sites of NNT-AS1 showed miR-214-5p as its direct target and NNT-AS1 as potential absorber for this microRNA, in turn increasing the expression of transcription factor smad4. Conclusion The data suggests that NNT-AS1 can be positively used as a potential biomarker and indicator of DN and causes extracellular matrix (ECM) accumulation and inflammation of human 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.


2019 ◽  
Vol 19 (7) ◽  
pp. 1055-1063
Author(s):  
Fenqin Chen ◽  
Guozhu Wei ◽  
Yang Zhou ◽  
Xiaoyu Ma ◽  
Qiuyue Wang

Background: Although the pathogenetic mechanism of Diabetic Kidney Disease (DKD) has not been elucidated, an inflammatory mechanism may be a potential contributor. Monocyte chemotactic protein-1 (MCP-1) is suggested to be implicated in the development of DKD by playing a role in the infiltration of monocyte/macrophage. The aim of this study was to investigate the expression of MCP-1 under high glucose conditions, as well as the effects of microRNA-192 (miR-192) under these conditions, and to study the regulatory mechanism of MCP-1 in DKD. <p></p> Methods: Rat glomerular mesangial cells were cultured in high glucose or isotonic mannitol. The messenger RNA(mRNA) expression of miR-192, miR-200b, miR-200c, E-box-binding homeobox 1 (Zeb1), and MCP-1 was then detected by real-time PCR, and the protein expression of Zeb1 and MCP- 1 was assessed by western blotting. The rat mesangial cells were transfected with an miR-192 inhibitor, NC inhibitor , and transfected with siRNA Zeb1, siNC. The cells were then cultured in high glucose to detect the mRNA expression of miR-192, miR-200b, miR-200c, Zeb1, and MCP-1 using realtime PCR, and Zeb1 and MCP-1 protein expression were determined by western blotting. <p></p> Results: MiR-192, miR-200b, miR-200c, and MCP-1 were overexpressed, whereas Zeb1 was downregulated when cultured in high glucose (P < 0.05). After transfection with an miR-192 inhibitor, the expression of miR-192, miR-200b, miR-200c, and MCP-1 was downregulated, whereas Zeb1 was increased, and these differences were statistically significant (P < 0.05). The observed changes in the expression in the NC inhibitor transfection group were similar to that of non-transfected cell lines. Silencing the expression of Zeb1 resulted in a significant increase in the expression of miR-192, miR- 200b, miR-200c, and MCP-1 (P < 0.05). The observed changes in the SiNC transfection group were similar to those of non-transfected cell lines. <p></p> Conclusions: MiR-192 expression was upregulated to increase the expression of inflammatory factor MCP-1 by inhibiting the expression of Zeb1, which was mediated by breaking the regulatory loop of Zeb1 and miR-200b/c in rat mesangial cells cultured in high glucose.


2011 ◽  
Vol 2011 ◽  
pp. 1-10 ◽  
Author(s):  
Rekha Singh

Ang II is shown to mediate the stimulatory effect of high glucose on TGF-b1 and extracellular matrix proteins in glomerular mesangial cells. Also inhibition of Ang II formation in cell media (extracellular) and lysates (intracellular) blocks high-glucose effects on TGF-b1 and matrix more effectively compared to inhibition of extracellular Ang II alone. To investigate whether intracellular Ang II can stimulate TGF-b1 and matrix independent of extracellular Ang II, cultured human mesangial cells were transfected with Ang II to increase intracellular Ang II levels and its effects on TGF-b1 and matrix proteins were determined. Prior to transfection, cells were treated with candesartan to block extracellular Ang II-induced responses via cell membrane AT1 receptors. Transfection of cells with Ang II resulted in increased levels of intracellular Ang II which was accompanied by increased production of TGF-b1, collagen IV, fibronectin, and cell proliferation as well. On further examination, intracellular Ang II was found to activate Stat3 transcription factor including increased Stat3 protein expression, tyrosine 705 phosphorylation, and DNA-binding activity. Treatment with AG-490, an inhibitor of Jak2, did not block intracellular Ang II-induced Stat3 phosphorylation at tyrosine 705 residue indicating a Jak2-independent mechanism used by intracellular Ang II for Stat3 phosphorylation. In contrast, extracellular Ang II-induced tyrosine 705 phosphorylation of Stat3 was inhibited by AG-490 confirming the presence of a Jak2-dependent pathway. These findings suggest that intracellular Ang II increases TGF-b1 and matrix in human mesangial cells and also activates Stat3 transcription factor without involvement of the extracellular Ang II signaling pathway.


2021 ◽  
Author(s):  
Ximei Guan ◽  
Weijian Ni ◽  
Jing Zeng ◽  
Hong Zhou ◽  
Linqin Tang

Abstract Background: Berberine plays a critical role of the glomerular mesangial cells (GMCs) abnormal proliferation during diabetic nephropathy (DN). This study aims to explore the intervention effect of BBR on DN mice and investigate the potential mechanism targeting abnormal GMCs proliferation. Methods: Streptozotocin-induced mice were used to determine the effect of BBR on the renal injury. In vitro, GMCs are cultured in high glucose (30 mmol/L). EdU and MTT assay are used for screening the optimum BBR concentration and intervention time. Flow cytometry is applied to analyze the cell cycle re-distribution. Western blot and RT-qPCR are devoted to studying the relative expression of molecules in PI3K/AKT/AS160/GLUT4 signaling pathway. Additionally, 2-NBDG assay is selected for measuring the glucose uptake of GMCs. Results: HE and PAS staining revealed that the notable mesangial matrix expansion, glomerular hypertrophy and glycogen deposition in diabetic kidney can be alleviated after BBR treatment. Moreover, BBR significantly reduced the positive expression of GLUT4 in tubulointerstitium and glomerular region. EdU shows that high glucose induces the abnormal proliferation of GMCs, which becomes more apparently as time goes on (20h→28h). Meantime, BBR (60 and 90 μmol/L) can not only increase the proportion of G1 phase, but also reduce the proportion of S phase. After 24 h, the same sort of phenomenon has cropped up in BBR (30 μmol/L) group. BBR (60 μmol/L)) significantly degraded the levels of PI3K-p85, p-AKT, p-AS160, and the membrane-GLUT4, while indistinguishable changes of their total protein expressions. Additionally, BBR prominently reduced the glucose uptake and retard the cell cycle of GMCs to stay at G1 phase. Conclusions: The rearrangement effect of BBR on cell cycle is related with PI3K/AKT signaling pathway and GLUT4 trafficking. The key findings of our study collectively indicate that the treatment of GMCs proliferation can be a novel therapeutic strategy in DN.


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