scholarly journals LncRNA Hoxb3os protects podocytes from high glucose-induced cell injury through autophagy dependent on the Akt-mTOR signaling pathway

2021 ◽  
Author(s):  
Juan Jin ◽  
Jianguang Gong ◽  
Li Zhao ◽  
Yiwen Li ◽  
Qiang He
Keyword(s):  
Diabetic Nephropathy ◽  
Signaling Pathway ◽  
High Glucose ◽  
Cell Injury ◽  
Damage Model ◽  
Mtor Signaling ◽  
Cell Counting ◽  
Tunel Staining ◽  
Mtor Signaling Pathway ◽  
Potential Biomarker

Background: Diabetic nephropathy (DN) is in the first place of the causes that lead to end-stage renal disease in the world. Thus, it is urgent to develop a novel diagnostic or therapeutic strategy that could stop the progression of diabetic nephropathy. Methods: RNA-sequencing was conducted in high glucose (HG)-treated MPC5 cells (podocytes). Cell morphology was examined under a light microscope. Upon high-glucose challenge, the effects of lncRNA Hoxb3os overexpression on MPC5 cells apoptosis, viability, autophagy and Akt-mTOR signaling were evaluated using flow cytometry, Cell Counting Kit-8, qRT-PCR, and Western blotting. TUNEL staining and ELISA were performed to confirm the establishment of DN model in db/db mice. Results: High-glucose exposure dramatically altered lncRNA expression profile in MPC5 cells (fold change>2), including 305 upregulated lncRNAs and 451 downregulated lncRNAs. LncRNA Hoxb3os expression was significantly reduced in the HG-induced podocyte damage model, as well as in the renal tissues from db/db mice with spontaneous DN. Overexpression of Hoxb3os significantly reduced the apoptosis rate and increased the viability of MPC5 cells under HG conditions. Further study revealed that exogenous Hoxb3os increased autophagy level in HG-exposed MPC5 cells via abrogating Akt-mTOR signaling pathway and that the process was possibly implicated in the upregulation of SIRT1. Conclusion: LncRNA Hoxb3os protected podocytes from HG-induced damage by regulating Akt-mTOR pathway and cell autophagy. Thus, lncRNA Hoxb3os appears as a potential biomarker in the diagnosis and treatment of DN in the future.

scholarly journals Rapamycin Antagonizes BCRP-Mediated Drug Resistance Through the PI3K/Akt/mTOR Signaling Pathway in mPRα-Positive Breast Cancer

2021 ◽  
Vol 11 ◽  
Author(s):  
Jing Zhang ◽  
Jing Hu ◽  
Weiwei Li ◽  
Chunyan Zhang ◽  
Peng Su ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Signaling Pathway ◽  
Therapeutic Option ◽  
Poor Response ◽  
Mtor Signaling ◽  
Cell Counting ◽  
Mtor Signaling Pathway ◽  
Potential Biomarker ◽  
Response To Chemotherapy

PurposeOverexpression of breast cancer (BCa) resistance protein (BCRP) is detected in approximately 30% of BCa cases. BCRP indicates a poor response to chemotherapy, and it has become a classic target to overcome drug-resistant tumor cells. In this study, we aimed to explore the mechanism of BCRP overexpression and a strategy to reverse this overexpression in invasive BCa.MethodsBCRP expression in BCa tissues was determined by immunohistochemistry. GSE25066 was downloaded from the NCBI GEO database. Western blot was used to determine the expression of key molecules in vitro. Cell counting kit-8 assays were used to assess the drug response of BCa cells.ResultsOur results suggested that BCRP is an independent risk factor for BCa. We further established that upon 17α-PG binding, membrane progesterone receptor α (mPRα) promoted BCRP expression via the PI3K/Akt/mTOR signaling pathway. mPRα physically interacted with p-Akt1 S473. Moreover, rapamycin, an inhibitor of mTOR complex 1 (mTORC1), downregulated BCRP expression and enhanced the effects of particular drugs, including doxorubicin and paclitaxel.ConclusionBCRP is a potential biomarker of poor prognosis in BCa. BCRP expression is regulated by 17α-PG in mPRα-positive BCa cells through the PI3K/Akt/mTOR signaling pathway. Rapamycin might enhance the therapeutic effect of chemotherapy agents in mPRα-positive MDA-MB-453/BCRP cells and might be a therapeutic option for mPRα-positive invasive BCa with BCRP overexpression.

scholarly journals Circ-ACTR2 aggravates the high glucose-induced cell dysfunction of human renal mesangial cells through mediating the miR-205-5p/HMGA2 axis in diabetic nephropathy

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Jie Yun ◽  
Jinyu Ren ◽  
Yufei Liu ◽  
Lijuan Dai ◽  
Liqun Song ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Diabetic Nephropathy ◽  
High Glucose ◽  
Cell Injury ◽  
Mesangial Cells ◽  
Protein Detection ◽  
Cell Counting ◽  
Luciferase Reporter ◽  
Enzyme Linked Immunosorbent Assay ◽  
Cell Dysfunction

Abstract Background Circular RNAs (circRNAs) have been considered as pivotal biomarkers in Diabetic nephropathy (DN). CircRNA ARP2 actin-related protein 2 homolog (circ-ACTR2) could promote the HG-induced cell injury in DN. However, how circ-ACTR2 acts in DN is still unclear. This study aimed to explore the molecular mechanism of circ-ACTR2 in DN progression, intending to provide support for the diagnostic and therapeutic potentials of circ-ACTR2 in DN. Methods RNA expression analysis was conducted by the quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Cell growth was measured via Cell Counting Kit-8 and EdU assays. Inflammatory response was assessed by Enzyme-linked immunosorbent assay. The protein detection was performed via western blot. Oxidative stress was evaluated by the commercial kits. The molecular interaction was affirmed through dual-luciferase reporter and RNA immunoprecipitation assays. Results Circ-ACTR2 level was upregulated in DN samples and high glucose (HG)-treated human renal mesangial cells (HRMCs). Silencing the circ-ACTR2 expression partly abolished the HG-induced cell proliferation, inflammation and extracellular matrix accumulation and oxidative stress in HRMCs. Circ-ACTR2 was confirmed as a sponge for miR-205-5p. Circ-ACTR2 regulated the effects of HG on HRMCs by targeting miR-205-5p. MiR-205-5p directly targeted high-mobility group AT-hook 2 (HMGA2), and HMGA2 downregulation also protected against cell injury in HG-treated HRMCs. HG-mediated cell dysfunction was repressed by miR-205-5p/HMGA2 axis. Moreover, circ-ACTR2 increased the expression of HMGA2 through the sponge effect on miR-205-5p in HG-treated HRMCs. Conclusion All data have manifested that circ-ACTR2 contributed to the HG-induced DN progression in HRMCs by the mediation of miR-205-5p/HMGA2 axis.

scholarly journals (Pro)renin receptor regulates autophagy and apoptosis in podocytes exposed to high glucose

2015 ◽  
Vol 309 (3) ◽  
pp. E302-E310 ◽  
Author(s):  
Caixia Li ◽  
Helmy M. Siragy
Keyword(s):  
Signaling Pathway ◽  
High Glucose ◽  
Caspase 3 ◽  
Mtor Signaling ◽  
Autophagic Flux ◽  
Bafilomycin A1 ◽  
Mtor Signaling Pathway ◽  
Autophagosome Formation ◽  
Podocyte Injury ◽  
Protein Levels

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.

scholarly journals Dihydromyricetin promotes autophagy and attenuates renal interstitial fibrosis by regulating miR-155-5p/PTEN signaling in diabetic nephropathy

2019 ◽  
Author(s):  
Liming Guo ◽  
Kuibi Tan ◽  
Qun Luo ◽  
Xu Bai
Keyword(s):  
Diabetic Nephropathy ◽  
Signaling Pathway ◽  
Rat Model ◽  
Interstitial Fibrosis ◽  
Mtor Signaling ◽  
Luciferase Assay ◽  
Luciferase Reporter ◽  
Mtor Signaling Pathway ◽  
Renal Interstitial Fibrosis ◽  
Gene Assay

Diabetic nephropathy (DN) is the most common complication of diabetes and is prone to kidney failure. Dihydromyricetin (DHM) has been reported to have a variety of pharmacological activities. This study aims to explore the effect of DHM on DN and the underlying molecular mechanism. An in vivo DN rat model was established. The degree of renal interstitial fibrosis (RIF) was detected by hematoxylin-eosin (HE) staining, Masson's trichrome staining, and immunohistochemistry (IHC). In vitro, NRK-52E cells were divided into four groups: normal glucose (NG), high glucose (HG), HG+DHM, and HG+rapamycin (autophagy inhibitor). The levels of autophagy- and fibrosis-related proteins were analyzed by western blotting. The expression of miR-155-5p and phosphatase and tensin homolog deleted on chromosome ten (PTEN) and their relationship were assessed by quantitative reverse transcription (qRT)-PCR and dual luciferase reporter gene assay. Our results showed that RIF was increased in DN rat model and in HG-induced NRK-52E cells. DHM treatment attenuated the increased RIF and also increased autophagy. MiR-155-5p expression was increased, while PTEN expression was decreased in DN rat and cell model, and DHM reversed both effects. Dual luciferase assay showed that PTEN was the target gene of miR-155-5p. DHM inhibited HG-induced fibrosis and promoted autophagy by inhibiting miR-155-5p expression in NRK-52E cells. In addition, DHM promoted autophagy by inhibiting the PI3K/AKT/mTOR signaling pathway. In conclusion, DHM promotes autophagy and attenuates RIF by regulating the miR-155-5p/PTEN signaling and PI3K/AKT/mTOR signaling pathway in DN.

scholarly journals Hyperin Alleviates Triptolide-Induced Ovarian Granulosa Cell Injury by Regulating AKT/TSC1/mTORC1 Signaling

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Fang You ◽  
Junyan Cao ◽  
Li Cheng ◽  
Xiaogu Liu ◽  
Li Zeng
Keyword(s):  
Signaling Pathway ◽  
Granulosa Cell ◽  
High Performance ◽  
Cell Injury ◽  
Ovarian Function ◽  
Interaction Network ◽  
Mtor Signaling ◽  
Network Pharmacology ◽  
Mtor Signaling Pathway ◽  
Mtorc1 Signaling

Premature ovarian insufficiency (POI) is characterized by the loss of ovarian function before 40 years of age and affects approximately 1% of women worldwide. Caragana sinica is a traditional Miao (a Chinese ethnic minority) medicine that improves ovarian function and follicular development. In the present study, we aimed to investigate the effect of active ingredients of C. sinica on POI and determine underlying mechanisms. Herein, the chemical composition of the C. sinica compound was analyzed using ultra-high-performance liquid chromatography, which identified hyperin (HR) as one of the main ingredients in C. sinica. Then, interaction targets of HR and POI were predicted and analyzed using network pharmacology and bioinformatics. The effect of HR on triptolide (TP)-induced granulosa cell injury was evaluated, and the underlying mechanism was explored based on bioinformatic results. A total of 100 interaction targets for POI and HR were obtained. The protein-protein interaction network of identified interaction targets emphasized the topological importance of AKT1. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed that HR might regulate POI by modulating the mechanistic target of rapamycin (mTOR) signaling pathway. In addition, the KEGG graph of the mTOR signaling pathway revealed that AKT phosphorylation inhibits the TSC1/2, while TSC1/2 activation inhibits the expression of mTORC1. The fundamental experiment revealed that HR increased proliferation, progesterone receptor levels, and estradiol levels decreased by TP in KGN cells. Additionally, HR alleviated TP-induced apoptosis and G1/G1 phase arrest in KGN cells. Western blotting demonstrated that HR increased the phosphorylation of AKT and mTORC1 and decreased TSC1 expression in TP-induced KGN cells. Collectively, our findings revealed that HR alleviates TP-induced granulosa cell injury by regulating AKT/TSC1/mTORC1 signaling, providing insight into the treatment of POI.

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.

Kaempferol reversals retinal ischemia/reperfusion (IR) injury through activating of PI3K/Akt/mTOR signaling pathway

2021 ◽  
Author(s):  
Da Sun ◽  
Fusheng Shang ◽  
Dagui Chen ◽  
Wenwen Wang ◽  
lili lin
Keyword(s):  
Oxidative Damage ◽  
Signaling Pathway ◽  
Inflammatory Cytokines ◽  
Ischemia Reperfusion ◽  
Retinal Ischemia ◽  
Mtor Signaling ◽  
Cell Counting ◽  
Mtor Signaling Pathway ◽  
Autophagy Gene ◽  
Retinal Vascular Occlusion

Abstract Purpose Retinal ischemia/reperfusion (IR) injury is associated with many ocular diseases, including acute glaucoma, diabetic retinopathy, and retinal vascular occlusion. However, currently there are no effective medications to prevent the development ofretinal IR injury.Kaempferol is a kind of plant extract which has showed an excellent ability to inhibit the inflammation.. Materials and Methods In this study, both in vitro and in vivo retinaloxidative damage models were established.Cell viability was assessed by Cell Counting Kit-8 assay. Apoptosis was examined using flow cytometry analysis.Atherosclerotic lesion analysis was performed using hematoxylin-eosin staining,The expressions of Inflammatory cytokines were detected by quantitative real-time PCR and ELISA respectively.The effect of expression of apoptosis、utophagy and the PI3K/Akt/mTOR signaling pathway related pathway was evaluated by Western blot. Results We found kaempferol was able to protect the viability of ARPE-19 cells against oxidative damage by reducing its apoptosis. In addition, it also kept structurally complete epithelium, stroma and endothelium of cornea after oxidative damage. Moreover, it also able to reduce the expression of inflammatory cytokines and increased the expression of anti-inflammatory cytokines.Kaempferol was able to enhanced the expression of anti-apoptotic genes BCL-2, and reduced the expression of autophagy gene Beclin 1 and increased the expression of anti-autophagy gene LC-3,was also able to enhance the expression PI3K and the phosphorylation ofAkt andmTOR. Conclusion Kaempferolreversals retinal ischemia/reperfusion (IR) injury through activating of PI3K/Akt/mTOR signaling pathway.

scholarly journals AMP-Activated Protein Kinase Alleviates Extracellular Matrix Accumulation in High Glucose-Induced Renal Fibroblasts through mTOR Signaling Pathway

2015 ◽  
Vol 35 (1) ◽  
pp. 191-200 ◽  
Author(s):  
Xia Luo ◽  
Lingyan Deng ◽  
Laxmi Pangeni Lamsal ◽  
Wenjuan Xu ◽  
Cheng Xiang ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Protein Kinase ◽  
Signaling Pathway ◽  
High Glucose ◽  
Mtor Signaling ◽  
Dependent Manner ◽  
Mtor Signaling Pathway ◽  
Matrix Synthesis ◽  
Matrix Accumulation ◽  
Amp Activated Protein Kinase

Background/Aims: Extracellular matrix accumulation contributes significantly to the pathogenesis of diabetic nephropathy. Although AMP-activated protein kinase (AMPK) has been found to inhibit extracellular matrix synthesis by experiments in vivo and vitro, its role in alleviating the deposition of extracellular matrix in renal interstitial fibroblasts has not been well defined. Methods: Currently, we conducted this study to investigate the effects of AMPK on high glucose-induced extracellular matrix synthesis and involved intracellular signaling pathway by using western blot in the kidney fibroblast cell line (NRK-49f). Results: Collagen IV protein levels were significantly increased by high glucose in a time-dependent manner. This was associated with a decrease in Thr72 phosphorylation of AMPK and an increase in phosphorylation of mTOR on Ser2448. High glucose-induced extracellular matrix accumulation and mTOR activation were significantly inhibited by the co-treatment of rAAV-AMPKα1312 (encoding constitutively active AMPKα1) whereas activated by r-AAV-AMPKα1D157A (encoding dominant negative AMPKα1). In cultured renal fibroblasts, overexpression of AMPKα1D157A upregulated mTOR signaling and matrix synthesis, which were ameliorated by co-treatment with the inhibitor of mTOR, rapamycin. Conclusion: Collectively, these findings indicate that AMPK exerts renoprotective effects by inhibiting the accumulation of extracellular matrix through mTOR signaling pathway.

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