scholarly journals High glucose downregulates myocardin expression in rat glomerular mesangial cells via the ERK signaling pathway

Oncotarget ◽  
2017 ◽  
Vol 8 (50) ◽  
pp. 87390-87400 ◽  
Author(s):  
Ming Li ◽  
Lijuan Xu ◽  
Guowei Feng ◽  
Yan Zhang ◽  
Xin Wang ◽  
...  
2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Le Zhang ◽  
Qian Dai ◽  
Lanlan Hu ◽  
Hua Yu ◽  
Jing Qiu ◽  
...  

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.


2021 ◽  
Vol 11 ◽  
Author(s):  
Kai Zhuang ◽  
Xiyu Jiang ◽  
Renbin Liu ◽  
Cunsi Ye ◽  
Yumei Wang ◽  
...  

Oxidative stress is the main factor responsible for the induction of diabetic renal fibrosis. Thus, improving the state of oxidative stress can effectively prevent the further deterioration of diabetic nephropathy (DN). Previous research has shown that formononetin (FMN), a flavonoid with significant antioxidant activity and Sirt1 activation effect, can improve diabetic renal fibrosis. However, the exact mechanisms underlying the effect of FMN on diabetic renal fibrosis have yet to be elucidated. In this study, we carried out in vivo experiments in a db/db (diabetic) mouse model and demonstrated that FMN activated the nuclear factor E2-related factor 2 (Nrf2)/antioxidant response element (ARE) signaling pathway and improved oxidative stress by increasing levels of sirtuin-1 (Sirt1) protein level in renal tissue. We also found that this process reversed the up-regulation of fibronectin (FN) and intercellular adhesion molecule 1 (ICAM-1) and led to an improvement in renal insufficiency. In vitro results further showed that FMN significantly reversed the upregulation of FN and ICAM-1 in glomerular mesangial cells (GMCs) exposed to high glucose. FMN also promoted the expression of Nrf2 and widened its nuclear distribution. Thus, our data indicated that FMN inhibited hyperglycemia-induced superoxide overproduction by activating the Nrf2/ARE signaling pathway. We also found that FMN up-regulated the expression of Sirt1 and that Sirt1 deficiency could block the activation of the Nrf2/ARE signaling pathway in GMCs induced by high glucose. Finally, we found that Sirt1 deficiency could reverse the down-regulation of FN and ICAM-1 induced by FMN. Collectively, our data demonstrated that FMN up-regulated the expression of Sirt1 to activate the Nrf2/ARE signaling pathway, improved oxidative stress in DN to prevent the progression of renal fibrosis. Therefore, FMN probably represents an efficient therapeutic option of patients with DN.


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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