scholarly journals Jujuboside A Protects H9C2 Cells from Isoproterenol-Induced Injury via Activating PI3K/Akt/mTOR Signaling Pathway

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Dandan Han ◽  
Changrong Wan ◽  
Fenghua Liu ◽  
Xiaolong Xu ◽  
Linshu Jiang ◽  
...  
Keyword(s):  
Cell Viability ◽  
Signaling Pathway ◽  
Morphological Changes ◽  
Cell Damage ◽  
Heart Diseases ◽  
Biological Effects ◽  
Mtor Signaling ◽  
Dependent Manner ◽  
H9c2 Cells ◽  
Mtor Signaling Pathway

Jujuboside A is a kind of the saponins isolated from the seeds ofZiziphus jujuba, which possesses multiple biological effects, such as antianxiety, antioxidant, and anti-inflammatory effects; however, its mediatory effect on isoproterenol-stimulated cardiomyocytes has not been investigated yet. In this study, we tried to detect the protective effect and potential mechanism of JUA on ISO-induced cardiomyocytes injury. H9C2 cells were treated with ISO to induce cell damage. Cells were pretreated with JUA to investigate the effects on the cell viability, morphological changes, light chain 3 conversion, and the activation of PI3K/Akt/mTOR signaling pathway. Results showed that ISO significantly inhibited the cell viability in a time- and dose-dependent manner. JUA pretreatment could reverse the reduction of cell viability and better the injury of H9C2 cells induced by ISO. Western blot analysis showed that JUA could accelerate the phosphorylation of PI3K, Akt, and mTOR. Results also indicated that JUA could significantly decrease the ratio of microtubule-associated protein LC3-II/I in H9C2 cells. Taken together, our research showed that JUA could notably reduce the damage cause by ISO via promoting the phosphorylation of PI3K, Akt, and mTOR and inhibiting LC3 conversion, which may be a potential choice for the treatment of heart diseases.

scholarly journals The co-treatment of rosuvastatin with dapagliflozin synergistically inhibited apoptosis via activating the PI3K/AKt/mTOR signaling pathway in myocardial ischemia/reperfusion injury rats

Open Medicine ◽  
2020 ◽  
Vol 16 (1) ◽  
pp. 047-057
Author(s):  
Lei Gong ◽  
Xuyang Wang ◽  
Jinyu Pan ◽  
Mingjun Zhang ◽  
Dian Liu ◽  
...  
Keyword(s):  
Creatine Kinase ◽  
Signaling Pathway ◽  
Ischemia Reperfusion ◽  
Left Ventricular Pressure ◽  
Left Ventricular ◽  
Mtor Signaling ◽  
Maximal Rate ◽  
H9c2 Cells ◽  
Mtor Signaling Pathway ◽  
Cardioprotective Effects

AbstractObjectiveThe purpose of the present study was to evaluate the role of co-treatment of rosuvastatin (RSV) and dapagliflozin (DGZ) preconditioning in myocardium ischemia/reperfusion (I/R) injury and to further investigate the underlying mechanism.MethodsSprague-Dawley (SD) rats (n = 25) were divided into five groups randomly: (1) Sham, (2) I/R, (3) I/R + RSV (10 mg/kg), (4) IR + DGZ (1 mg/kg), and (5) I/R + RSV (10 mg/kg) + DGZ (1 mg/kg). The I/R model was induced with 30 min of left anterior descending occlusion followed by 120 min of reperfusion.ResultsIn vivo pretreatment with RSV and DGZ, respectively, showed a significant reduction of infarction size, a significant increase in the levels of left ventricular systolic pressure, and maximal rate increase in left ventricular pressure (+dp/dtmax), decrease in the levels of left ventricular end-diastolic pressure (LVEDP), maximal rate of decrease of left ventricular pressure (−dp/dtmax) and activity of cardiac enzymes of creatine kinase (CK), creatine kinase MB isoenzymes (CK-MB), and hyper-tensive cardiac troponin I compared with the I/R group. H9C2 cells were exposed to hypoxia/reoxygenation to simulate an I/R model. In vitro administration of 25 µM RSV and 50 µM DGZ significantly enhanced cell viability, upregulated the expression levels of p-PI3K, p-Akt, p-mTOR, and Bcl-2, whereas it downregulated cleaved-caspase3, Bax. TUNEL assay indicated that pretreatment with RSV and DGZ decreased the apoptosis of H9C2 cells.ConclusionThe combination of RSV and DGZ significantly enhances the cardioprotective effects compared with RSV or DGZ alone. RSV and DGZ have the potential cardioprotective effects against I/R injury by activating the PI3K/AKt/mTOR signaling pathway.

scholarly journals Autophagy protects gastric mucosal epithelial cells from ethanol-induced oxidative damage via mTOR signaling pathway

2017 ◽  
Vol 242 (10) ◽  
pp. 1025-1033 ◽  
Author(s):  
Weilong Chang ◽  
Jie Bai ◽  
Shaobo Tian ◽  
Muyuan Ma ◽  
Wei Li ◽  
...  
Keyword(s):  
Gastric Mucosa ◽  
Epithelial Cells ◽  
Oxidative Damage ◽  
Signaling Pathway ◽  
Cell Damage ◽  
Mtor Signaling ◽  
Adaptive Mechanism ◽  
Mtor Signaling Pathway ◽  
Mucosal Epithelial Cell ◽  
Ethanol Toxicity

Alcohol abuse is an important cause of gastric mucosal epithelial cell injury and gastric ulcers. A number of studies have demonstrated that autophagy, an evolutionarily conserved cellular mechanism, has a protective effect on cell survival. However, it is not known whether autophagy can protect gastric mucosal epithelial cells against the toxic effects of ethanol. In the present study, gastric mucosal epithelial cells (GES-1 cells) and Wistar rats were treated with ethanol to detect the adaptive response of autophagy. Our results demonstrated that ethanol exposure induced gastric mucosal epithelial cell damage, which was accompanied by the downregulation of mTOR signaling pathway and activation of autophagy. Suppression of autophagy with pharmacological agents resulted in a significant increase of GES-1 cell apoptosis and gastric mucosa injury, suggesting that autophagy could protect cells from ethanol toxicity. Furthermore, we evaluated the cellular oxidative stress response following ethanol treatment and found that autophagy induced by ethanol inhibited generation of reactive oxygen species and degradation of antioxidant and lipid peroxidation. In conclusion, these findings provide evidence that ethanol can activate autophagy via downregulation of the mTOR signaling pathway, serving as an adaptive mechanism to ameliorate oxidative damage induced by ethanol in gastric mucosal epithelial cells. Therefore, modifying autophagy may provide a therapeutic strategy against alcoholic gastric mucosa injury. Impact statement The effect and mechanism of autophagy on ethanol-induced cell damage remain controversial. In this manuscript, we report the results of our study demonstrating that autophagy can protect gastric mucosal epithelial cells against ethanol toxicity in vitro and in vivo. We have shown that ethanol can activate autophagy via downregulation of the mTOR signaling pathway, serving as an adaptive mechanism to ameliorate ethanol-induced oxidative damage in gastric mucosal epithelial cells. This study brings new and important insights into the mechanism of alcoholic gastric mucosal injury and may provide an avenue for future therapeutic strategies.

scholarly journals Chlorogenic acid protects PC12 cells against corticosterone-induced neurotoxicity related to inhibition of autophagy and apoptosis

2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Xiaowen Shi ◽  
Nian Zhou ◽  
Jieyi Cheng ◽  
Xunlong Shi ◽  
Hai Huang ◽  
...  
Keyword(s):  
Cell Viability ◽  
Chlorogenic Acid ◽  
Signaling Pathway ◽  
Pc12 Cells ◽  
Molecular Mechanism ◽  
Cell Activity ◽  
Neuronal Cell ◽  
Mtor Signaling ◽  
Specific Marker ◽  
Mtor Signaling Pathway

Abstract Background There are evidences that chlorogenic acid (CGA) has antidepressant effects, however the underlying molecular mechanism has not been well understood. The aim of the study was to explore the neuroprotective effect of CGA on corticosterone (CORT)-induced PC 12 cells and its mechanism, especially the autophagy pathway. Methods PC12 cells were incubated with CORT (0, 100, 200, 400 or 800 μM) for 24 h, cell viability was measured by MTT assay. PC12 cells were cultured with 400 μM of CORT in the absence or presence of CGA (25 μg/ml) for 24 h, morphologies and specific marker of autophagosome were observed by transmission electron microscope (TEM) and confocal immunofluorescence microscopy, respectively. In addition, PC12 cells were treated with different doses of CGA (0, 6.25, 12.5, 25 or 50 μg/ml) with or without CORT (400 μM) for 24 h, cell viability and changes in the morphology were observed, and further analysis of apoptotic and autophagic proteins, and expression of AKT/mTOR signaling pathway were carried out by Western blot. Specific inhibitors of autophagy 3-Methyladenine (3-MA) and chloroquine (CQ) were added to the PC12 cells cultures to explore the potential role of autophagy in CORT-induced neuronal cell apoptosis. Results Besides decreasing PC12 cell activity, CORT could also induce autophagy and apoptosis of PC12 cells, while CGA could reverse these effects. In addition, CGA treatment regulated AKT/mTOR signaling pathway in PC12 cells. CGA, similar to 3-MA and QC, significantly inhibited CORT-induced apoptosis in PC12 cells. Conclusions Our results provide a new molecular mechanism for the treatment of CORT-induced neurotoxicity by CGA, and suggest CGA may be a potential substance which is can alleviate depression.

scholarly journals Ginsenoside Rg3 Suppresses Proliferation and Induces Apoptosis in Human Osteosarcoma

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Yi Li ◽  
Jinying Lu ◽  
Furong Bai ◽  
Yanan Xiao ◽  
Yiran Guo ◽  
...  
Keyword(s):  
Western Blot ◽  
Signaling Pathway ◽  
Mtor Signaling ◽  
Assay Method ◽  
Osteosarcoma Cell ◽  
Dependent Manner ◽  
Ginsenoside Rg3 ◽  
Mtor Signaling Pathway ◽  
Human Osteosarcoma ◽  
Human Osteosarcoma Cells

Osteosarcoma is the most common primary malignancy of bone in children and the elderly. Recently, more and more researches have demonstrated that Ginsenoside Rg3 (Rg3) is involved in chemotherapy resistance in many cancer, making it a promising Chinese herbal monomer for oncotherapy. In this study, we investigated the efficacy of Rg3 in human osteosarcoma cell lines (MG-63, U-2OS, and SaOS-2). Cell proliferation was measured by CCK8 assay. The migration of cells was examined using the scratch assay method. Quantification of apoptosis was assessed further by flow cytometry. In addition, the expression of apoptosis-related genes (caspase9, caspase3, Bcl2, and Bax) were investigated using RT-PCR. We further investigated the protein level expression of Bcl 2, cleaved-caspase3, and PI3K/AKT/mTOR signaling pathway factors by Western blot assay. Our results revealed that Rg3 inhibited the proliferation and migration of human osteosarcoma cells and induced apoptosis in a concentration- and time-dependent manner. Western blot results showed that Rg3 reduced the protein expression of Bcl2 and PI3K/AKT/mTORbut increased the levels of cleaved-caspase3. Therefore, we hypothesized Rg3 inhibits the proliferation of osteosarcoma cell line and induces their apoptosis by affecting apoptosis-related genes (Bcl2, caspase3) as well as the PI3K/AKT/mTOR signaling pathway. To conclude, Rg3 is a new therapeutic agent against osteosarcoma.

scholarly journals Melatonin-induced Cell Rejuvenation from Long-term Ex-vivo passaging Functioned by its Restoration of Damaged Cell Autophagic Processes

2020 ◽  
Author(s):  
Yi-Zhou Tan ◽  
Xin-Yue Xu ◽  
Ji-Min Dai ◽  
Yuan Yin ◽  
Xiao-Tao He ◽  
...  
Keyword(s):  
Stem Cells ◽  
Signaling Pathway ◽  
Cellular Senescence ◽  
Ex Vivo ◽  
Mtor Signaling ◽  
Beclin 1 ◽  
Dependent Manner ◽  
Mtor Signaling Pathway ◽  
Associated Proteins

Abstract Background: Stem cells undergone long-term ex-vivo expansion are most likely functionally compromised (namely cellular senescence) in terms of their stem cell properties and therapeutic potentials. Due to the ability to attenuate cellular senescence, melatonin (MLT) has been proposed as an adjuvant across long-term cell expansion protocols, but the underlying mechanism remains largely unknown. Methods: Human periodontal ligament stem cells (PDLSCs) were isolated and cultured ex-vivo for 15 passages, and passage 2, 7 and 15 cells were used to interrogate the cellular senescence and alteration in cell autophagy during long-term expansion. The cellular senescence features were evidenced by senescence-associated β-galacotosidase (SA-β-gal) activity and the expression of senescence-related proteins including p53, p21, p16 and γ-H2AX. Electronic microscope was used to observe the autophagic vesicles. Adenovirus mRFP-GFP-LC3 was transfected to indicate the alteration of autophagic flux during long-term expansion, and the autophagy-associated proteins Atg7, Beclin-1, LC3-II and p62 were evaluated by Western blot. Results: It was found that long-term in-vitro passaging led to an accumulated SA-β-gal, elevated expressions of p53, p21, p16 and γ-H2AX, along with downregulated autophagy-associated proteins Atg7, Beclin-1 and LC3 as well as a mounting autophagy substrate p62. In accordance with expectation, supplemented with MLT not only ameliorated cells to a younger state but also restored the impaired autophagy level in senescent cells. Additionally, we demonstrated that autophagy inhibitor could block such MLT-induced cell rejuvenation. When the underlying signaling pathways involved was interrogated, we found that MLT receptor (MT) participated in mediating MLT-related autophagy restoration by regulating PI3K/AKT/mTOR signaling pathway.Conclusions: The present study suggests that MLT may rejuvenate long-term expansion-caused cellular senescence by restoring autophagy, more likely via PI3K/AKT/mTOR signaling pathway in an MT-dependent manner. This is the first report identifying the MT-dependent PI3K/AKT/mTOR signaling involved in MLT-induced autophagy alteration, pointing to a potential target for using autophagy-restoring agents such as MLT to develop optimized clinical-scale cell production protocols.

scholarly journals Activated mTORC1-SIRT6 Mediates Myofibroblast Differentiation and Idiopathic Pulmonary Fibrosis

2021 ◽  
Author(s):  
Ji Zhang ◽  
Yi Hu ◽  
Huiping Huang ◽  
Qun Liu ◽  
Yang Du ◽  
...  
Keyword(s):  
Pulmonary Fibrosis ◽  
Signaling Pathway ◽  
Mtor Signaling ◽  
Signalling Pathway ◽  
Lung Fibroblasts ◽  
Myofibroblast Differentiation ◽  
Dependent Manner ◽  
Mtor Signaling Pathway ◽  
Mtorc1 Pathway ◽  
Tgf Β1

Abstract BackgroundIdiopathic pulmonary fibrosis (IPF) is characterised by accumulation of myofibroblasts and deposition of extracellular matrix proteins. Fibroblast-to-myofibroblast transdifferentiation and myofibroblast hyperproliferation plays a major role in pulmonary fibrosis. Moreover, mTOR signaling pathway and SIRT6 play a critical role in pulmonary fibrosis. However, the mechanisms whether SIRT6 affect the myofibroblasts differentiation during IPF remain unclear.MethodWe investigated myofibroblast differentiation using a bleomycin-induced mouse pulmonary fibrosis model and TGF-b1 induced human fetal lung fibroblasts (MRC5) in vitro. We used both SIRT6 siRNA and rapamycin to study the role of SIRT6 and mTOR signaling pathway in the normal human lung fibroblasts and the myofibroblasts from human IPF lungs.ResultsOur data show that high level of SIRT6 was detected in IPF samples, and SIRT6 was significantly upregulated by TGF-β1 in a time and concentration-dependent manner. SIRT6 expression and activation of mTORC1 signalling pathway were upregulated in fibrotic lung tissues and primary lung fibroblasts isolated from patients with IPF and bleomycin-challenged mice. Furthermore, rapamycin treatment inhibited mTORC1 pathway activity and SIRT6 protein expression. SIRT6 SiRNA failed to mediate the activity of mTORC1 pathway and autophagy induction. However, SIRT6 knockdown could promote TGF-b1 induced pro-fibrotic cytokines.ConclusionActivated mTORC1 signalling pathway regulated SIRT6 overexpression. Deficiency of SIRT6 mediated myofibroblasts differentiation through induced pro-fibrotic cytokines production in the present of TGF-β1. The study indicated that manipulations of SIRT6 expression may provide a new therapeutic strategy to prevent and reverse the progression of pulmonary fibrosis.

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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