Repression of miR-217 protects against high glucose-induced podocyte injury and insulin resistance by restoring PTEN-mediated autophagy pathway

High glucose reduces autophagy and enhances apoptosis of podocytes. Previously, we reported that high glucose induced podocyte injury through upregulation of the (pro)renin receptor (PRR). We hypothesized that increasing PRR reduces autophagy and increases apoptosis of mouse podocytes exposed to high glucose via activation of the PI3K/Akt/mTOR signaling pathway. Mouse podocytes were cultured in normal (5 mmol/l) or high (25 mmol/l) d-glucose for 48 h. High glucose significantly increased mRNA and protein levels of PRR, phosphorylation of PI3K/Akt/mTOR, and p62. In contrast, high glucose decreased activation of UNC-51-like kinase-1 (ULK1) by phosphorylating Ser757 and protein levels of microtubule-associated protein-1 light chain 3B (LC3B)-II and Lamp-2. Bafilomycin A1 increased LC3BII and p62 accumulation in high-glucose-treated cells. High glucose reduced the autophagic flux. Confocal microscopy studies showed significant reduction in the protein level of LC3B in response to high glucose. Cyto-ID autophagy staining showed a significant decrease in autophagosome formation with high glucose. In the absence of PRR, activation of Akt with sc-79 or mTOR with MHY-1485 increased p62 accumulation. Caspase-3/7 activity and apoptosis monitored by TUNEL assay were significantly increased in podocytes treated with high glucose. PRR siRNA significantly reversed the effects of high glucose. Based on these data, we conclude that high glucose decreases autophagy and increases apoptosis in mouse podocytes through the PRR/PI3K/Akt/mTOR signaling pathway.

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Rosemary Extract Activates AMPK, Inhibits mTOR and Attenuates the High Glucose and High Insulin-Induced Muscle Cell Insulin Resistance

Applied Physiology Nutrition and Metabolism ◽

10.1139/apnm-2020-0592 ◽

2021 ◽

Author(s):

Hesham Shamshoum ◽

Filip Vlavcheski ◽

Rebecca E.K. MacPherson ◽

Evangelia Tsiani

Keyword(s):

Insulin Resistance ◽

Plasma Membrane ◽

Blood Glucose ◽

Glucose Uptake ◽

Muscle Cell ◽

High Glucose ◽

Serine Phosphorylation ◽

Rosemary Extract ◽

Insulin Levels ◽

High Insulin

Impaired action of insulin in skeletal muscle, termed insulin resistance, leads to increased blood glucose levels resulting in compensatory increase in insulin levels. The elevated blood glucose and insulin levels exacerbate insulin resistance and contribute to the pathogenesis of type 2 diabetes mellitus (T2DM). In previous studies we found attenuation of free fatty acid-induced muscle cell insulin resistance by rosemary extract (RE). In the present study we investigated the effects of RE on high glucose (HG) and high insulin (HI)-induced muscle cell insulin resistance. Exposure of L6 myotubes to 25 mM glucose and 100 nM insulin for 24 h, to mimic hyperglycemia and hyperinsulinemia, abolished the acute insulin-stimulated glucose uptake, increased the serine phosphorylation of IRS-1 and the phosphorylation/ activation of mTOR and p70S6K. Treatment with RE significantly improved the insulin-stimulated glucose uptake and increased the acute insulin-stimulated tyrosine phosphorylation while reduced the HG+HI-induced serine phosphorylation of IRS-1 and phosphorylation of mTOR and p70S6K. Additionally, treatment with RE significantly increased the phosphorylation of AMPK, its downstream effector ACC and the plasma membrane GLUT4 levels. Our data indicate a potential of RE to counteract muscle cell insulin resistance and more studies are required to investigate its effectiveness in vivo. Novelty: • Rosemary extract (RE) phosphorylated muscle cell AMPK and ACC under both normal and high glucose (HG)/high insulin (HI) conditions. • The HG/HI-induced serine phosphorylation of IRS-1 and activation of mTOR and p70S6K were attenuated by RE. • RE increased the insulin-stimulated glucose uptake by enhancing GLUT4 glucose transporter translocation to plasma membrane.

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KCNQ1OT1 inhibition alleviates high glucose-induced podocyte injury by adsorbing miR-23b-3p and regulating Sema3A

Clinical and Experimental Nephrology ◽

10.1007/s10157-021-02173-x ◽

2022 ◽

Author(s):

Bingru Fei ◽

Hui Zhou ◽

Zengjiao He ◽

Suyu Wang

Keyword(s):

High Glucose ◽

Podocyte Injury

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Insulin resistance induced by high glucose and high insulin precedes insulin receptor substrate 1 protein depletion in human adipocytes

Metabolism ◽

10.1016/j.metabol.2006.09.012 ◽

2007 ◽

Vol 56 (2) ◽

pp. 190-198 ◽

Cited By ~ 30

Author(s):

Frida Renström ◽

Jonas Burén ◽

Maria Svensson ◽

Jan W. Eriksson

Keyword(s):

Insulin Resistance ◽

Insulin Receptor ◽

High Glucose ◽

Insulin Receptor Substrate ◽

Human Adipocytes ◽

Insulin Receptor Substrate 1 ◽

Protein Depletion ◽

High Insulin

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Increased long noncoding RNA maternally expressed gene 3 contributes to podocyte injury induced by high glucose through regulation of mitochondrial fission

Cell Death and Disease ◽

10.1038/s41419-020-03022-7 ◽

2020 ◽

Vol 11 (9) ◽

Author(s):

Qiongxia Deng ◽

Ruowei Wen ◽

Sirui Liu ◽

Xiaoqiu Chen ◽

Shicong Song ◽

...

Keyword(s):

High Glucose ◽

Noncoding Rna ◽

Diabetic Kidney Disease ◽

Mitochondrial Fission ◽

Diabetic Mice ◽

Podocyte Injury ◽

Mitochondrial Translocation ◽

Maternally Expressed Gene 3

Abstract Excessive mitochondrial fission plays a key role in podocyte injury in diabetic kidney disease (DKD), and long noncoding RNAs (lncRNAs) are important in the development and progression of DKD. However, lncRNA regulation of mitochondrial fission in podocytes is poorly understood. Here, we studied lncRNA maternally expressed gene 3 (Meg3) in mitochondrial fission in vivo and in vitro using human podocytes and Meg3 podocyte-specific knockdown mice. Expression of lncRNA Meg3 in STZ-induced diabetic mice was higher, and correlated with the number of podocytes. Excessive mitochondrial fission of podocytes and renal histopathological and physiological parameters were improved in podocyte-specific Meg3 knockdown diabetic mice. Elongated mitochondria with attenuated podocyte damage, as well as mitochondrial translocation of dynamin-related protein 1 (Drp1), were decreased in Meg3 knockout podocytes. By contrast, increased fragmented mitochondria, podocyte injury, and Drp1 expression and phosphorylation were observed in lncRNA Meg3-overexpressing podocytes. Treatment with Mdivi1 significantly blunted more fragmented mitochondria and reduced podocyte injury in lncRNA Meg3-overexpressing podocytes. Finally, fragmented mitochondria and Drp1 mitochondrial translocation induced by high glucose were reduced following treatment with Mdivi1. Our data show that expression of Meg3 in podocytes in both human cells and diabetic mice was higher, which regulates mitochondrial fission and contributes to podocyte injury through increased Drp1 and its translocation to mitochondria.

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Store‐operated calcium entry mediated high glucose‐induced podocyte injury and mitochondrial impairment

The FASEB Journal ◽

10.1096/fasebj.2021.35.s1.05102 ◽

2021 ◽

Vol 35 (S1) ◽

Author(s):

Yu Tao ◽

Sarika Chaudhari ◽

Parisa Shotorbani ◽

Rong Ma

Keyword(s):

High Glucose ◽

Calcium Entry ◽

Podocyte Injury ◽

Mitochondrial Impairment ◽

Store Operated Calcium Entry

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miR-450a-5p eliminats MGO-induced insulin resistance via targeting CREB

10.21203/rs.2.12119/v1 ◽

2019 ◽

Author(s):

Cuifeng Wei ◽

Li Meng ◽

Yuting Zhang

Keyword(s):

Insulin Resistance ◽

Endothelial Cells ◽

Cell Invasion ◽

High Glucose ◽

Target Gene ◽

Cell Activity ◽

Luciferase Reporter ◽

Akt Pathway ◽

Potential Target ◽

In Cells

Abstract Background miR-450a-5p was involved in fat formation, but its role in insulin resistance remains unclear. This study further investigated the effects of miR-450a-5p in endothelial cells, with the aim of finding a potential target for diabetes mellitus. Methods Human umbilical vein endothelial cells (HUVECs) were severally treated with low-glucose, high-glucose, methylglyoxal (MGO), and insulin only or plus MGO. miR-450a-5p was up-regulated or down-regulated in treated HUVECs. miR-450a-5p expression in cells was measured by quantitative real-time polymerase chain reaction (qRT-PCR) assays. The cell activity was determined through MTT experiments. Transwell assay and oil red O staining were used for the detection of cell invasion and fat formation. The expressions of eNOS/AKT pathway-related proteins in cells were assessed by Western blot (WB) analysis. Furthermore, the target gene of miR-450a-5p was analyzed by double-luciferase reporter analysis, and its influence in eNOS/AKT pathway was estimated. Results miR-450a-5p decreased obviously in endothelial cells with high-glucose and MGO. Through in vitro cell experiments, we knew that MGO could not only intensify the activity of endothelial cells, but also accelerate cell invasion and fat accumulation, which could be reversed by up-regulated miR-450a-5p. Moreover, MGO inhibited eNOS/AKT pathway activation and NO release mediated by insulin, which were eliminated by up-regulated miR-450a-5p. Furthermore, CREB was the target gene of miR-450a-5p that had an activation effect on the eNOS/AKT pathway. Conclusions Up-regulated miR-450a-5p eliminated MGO-induced insulin resistance via targeting CREB, which might be a potential target to improve insulin resistance and benefit patients with related diseases.

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