Clusterin protects H9c2 cardiomyocytes from oxidative stress-induced apoptosis via Akt/GSK-3β signaling pathway.
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ABSTRACT:
SUBMITTER: Jun HO
PROVIDER: S-EPMC3041938 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:BackgroundEpigallocatechin-3-gallate (EGCg) with its potent anti-oxidative capabilities is known for its beneficial effects ameliorating oxidative injury to cardiac cells. Although studies have provided convincing evidence to support the cardioprotective effects of EGCg, it remains unclear whether EGCg affect trans-membrane signalling in cardiac cells. Here, we have demonstrated the potential mechanism for cardioprotection of EGCg against H2O2-induced oxidative stress in H9c2 cardiomyoblasts.ResultsExposing H9c2 cells to H2O2 suppressed cell viability and altered the expression of adherens and gap junction proteins with increased levels of intracellular reactive oxygen species and cytosolic Ca2+. These detrimental effects were attenuated by pre-treating cells with EGCg for 30 min. EGCg also attenuated H2O2-mediated cell cycle arrest at the G1-S phase through the glycogen synthase kinase-3β (GSK-3β)/β-catenin/cyclin D1 signalling pathway. To determine how EGCg targets H9c2 cells, enhanced green fluorescence protein (EGFP) was ectopically expressed in these cells. EGFP-emission fluorescence spectroscopy revealed that EGCg induced dose-dependent fluorescence changes in EGFP expressing cells, suggesting that EGCg signalling events might trigger proximity changes of EGFP expressed in these cells. Proteomics studies showed that EGFP formed complexes with the 67 kD laminin receptor, caveolin-1 and -3, β-actin, myosin 9, vimentin in EGFP expressing cells. Using in vitro oxidative stress and in vivo myocardial ischemia models, we also demonstrated the involvement of caveolin in EGCg-mediated cardioprotection. In addition, EGCg-mediated caveolin-1 activation was found to be modulated by Akt/GSK-3β signalling in H2O2-induced H9c2 cell injury.ConclusionsOur data suggest that caveolin serves as a membrane raft that may help mediate cardioprotective EGCg transmembrane signalling.
| S-EPMC3871020 | biostudies-literature
Project description:Our previous studies have assessed ginsenoside Rg1 (Rg1)-mediated protection in a type 1 diabetes rat model. To uncover the mechanism through which Rg1 protects against cardiac injury induced by diabetes, we mimicked diabetic conditions by culturing H9C2 cells in high glucose/palmitate. Rg1 had no toxic effect, and it alleviated the high glucose/palmitate damage in a dose-dependent manner, as indicated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay and lactate dehydrogenase release to the culture medium. Rg1 prevented high glucose/palmitate-induced cell apoptosis, assessed using cleaved caspase-3 and terminal deoxynucleotidyl transferase dUTP nick end labelling staining. Rg1 also reduced high glucose-/palmitate-induced reactive oxygen species formation and increased intracellular antioxidant enzyme activity. We found that Rg1 activates protein kinase B (AKT)/glycogen synthase kinase-3 (GSK-3?) pathway and antioxidant nuclear factor erythroid 2-related factor 2 (Nrf2) pathway, indicated by increased phosphorylation of AKT and GSK-3?, and nuclear translocation of Nrf2. We used phosphatidylinositol-3-kinase inhibitor Ly294002 to block the activation of the AKT/GSK-3? pathway and found that it partially reversed the protection by Rg1 and decreased Nrf2 pathway activation. The results suggest that Rg1 exerts a protective effect against high glucose and palmitate damage that is partially AKT/GSK-3?/Nrf2-mediated. Further studies are required to validate these findings using primary cardiomyocytes and animal models of diabetes.
| S-EPMC7348154 | biostudies-literature
Project description:Cryptotanshinone (CTT) is a natural product and a quinoid diterpene isolated from the root of the Asian medicinal plant, Salvia miltiorrhizabunge. Notably, CTT has a variety of anti-cancer actions, including the activation of apoptosis, anti-proliferation, and reduction in angiogenesis. We further investigated the anti-cancer effects of CTT using MTS, LDH, and Annexin V assay, DAPI staining, cell cycle arrest, and Western blot analysis in NSCLC cell lines. NSCLC cells treated with CTT reduced cell growth through PI3K/Akt/GSK3β pathway inhibition, G0/G1 cell cycle arrest, and the activation of apoptosis. CTT induced an increase of caspase-3, caspase-9, poly-ADP-ribose polymerase (PARP), and Bax, as well as inhibition of Bcl-2, survivin, and cellular-inhibitor of apoptosis protein 1 and 2 (cIAP-1 and -2). It also induced G0/G1 phase cell cycle arrest by decreasing the expression of the cyclin A, cyclin D, cyclin E, Cdk 2, and Cdk 4. These results highlight anti-proliferation the latent of CTT as natural therapeutic agent for NSCLC. Therefore, we investigated the possibility of CTT as an anti-cancer agent by comparing with GF, which is a representative anti-cancer drug.
| S-EPMC6163873 | biostudies-other
Project description:Trichosanthis Pericarpium (TP) is a traditional Chinese medicine for treating cardiovascular diseases. In this study, we investigated the effects of TP aqueous extract (TPAE) on hypoxia/reoxygenation (H/R) induced injury in H9c2 cardiomyocytes and explored the underlying mechanisms. H9c2 cells were cultured under the hypoxia condition induced by sodium hydrosulfite for 30 min and reoxygenated for 4 h. Cell viability was measured by MTT assay. The amounts of LDH, NO, eNOS, and iNOS were tested by ELISA kits. Apoptotic rate was detected by Annexin V-FITC/PI staining. QRT-PCR was performed to analyze the relative mRNA expression of Akt, Bcl-2, Bax, eNOS, and iNOS. Western blotting was used to detect the expression of key members in the PI3K/Akt pathway. Results showed that the pretreatment of TPAE remarkably enhanced cell viability and decreased apoptosis induced by H/R. Moreover, TPAE decreased the release of LDH and expression of iNOS. In addition, TPAE increased NO production and Bcl-2/Bax ratio. Furthermore, the mRNA and protein expression of p-Akt and eNOS were activated by TPAE pretreatment. On the contrary, a specific inhibitor of PI3K, LY294002 not only inhibited TPAE-induced p-Akt/eNOS upregulation but alleviated its anti-apoptotic effects. In conclusion, results indicated that TPAE protected against H/R injury in cardiomyocytes, which consequently activated the PI3K/Akt/NO signaling pathway.
| S-EPMC6222483 | biostudies-literature
Project description:Background:Diabetic cardiomyopathy (DCM), which is associated with many pathological processes, commonly occurs when advanced glycation end products (AGEs) are present. ?-carotene (BC) is a well-known vitamin A precursor that is found in many fruits and vegetables. BC can reduce the risk of cancer and cardiovascular disease. This study aimed to investigate the effect of BC on AGE-induced myocardial injury in vitro. Methods:Cell viability test was used to select 40 µM concentrations of BC to treat AGE-induced H2c9 cells. The cell apoptosis was detected by flow cytometry. Western blotting was used to measure the protein expression levels of Bcl-2-associated X protein (Bax), B-cell lymphoma-2 (Bcl-2), cleaved caspase-3, activating transcription factor 4 (ATF4), glucose-regulated protein 78 (GRP78), CCAAT/enhancer-binding protein homologous protein (CHOP), beclin 1, p62,microtubule-associated protein 1 light chain 3 (LC3), phosphorylated PI3K (p-PI3K), phosphorylated Akt (p-AKT), and phosphorylated mTOR (p-mTOR). Enzyme-linked immunosorbent assay (ELISA) was performed to measure the levels of lactate dehydrogenase (LDH) and cardiac troponin-1 (cTn-I). Reactive oxygen species (ROS) was detected by flow cytometry. The levels of malondialdehyde (MDA), glutathione peroxidase (GSH-Px), and superoxide dismutase (SOD) were used to determine MDA kits, SOD assay kit and GSH-Px kit, respectively. Results:BC significantly inhibited AGE-induced cell death and apoptosis in H9c2 cells. BC had a suppressive effect on intracellular ROS production and antioxidative enzyme reduction. Moreover, BC decreased hyperactive endoplasmic reticulum (ER) stress and autophagy in H9c2 cells. Furthermore, BC exerted a cardioprotective effect in AGE-induced H9c2 cells via the activation of the PI3K/Akt/mTOR signaling pathway. Conclusions:BC exhibited a cardioprotective effect AGE-induced apoptosis. Our study provides a foundation for further study into the potential value of BC for treating DCM or other heart diseases.
| S-EPMC7290636 | biostudies-literature
Project description:Activation of apoptosis in cardiomyocytes by saturated palmitic acids contributes to cardiac dysfunction in diabetic cardiomyopathy. Beta-catenin (b-catenin) is a transcriptional regulator of several genes involved in survival/anti-apoptosis. However, its role in palmitate-induced cardiomyocyte apoptosis remains unclear. Glucagon-like peptide 1 (GLP1) has been shown to exhibit potential cardioprotective properties. This study was designed to evaluate the role of b-catenin signalling in palmitate-induced cardiomyocyte apoptosis and the molecular mechanism underlying the protective effects of GLP1 on palmitate-stressed cardiomyocytes. Exposure of neonatal rat cardiomyocytes to palmitate increased the fatty acid transporter CD36-mediated intracellular lipid accumulation and cardiomyocyte apoptosis, decreased accumulation and nuclear translocation of active b-catenin, and reduced expression of b-catenin target protein survivin and BCL2. These detrimental effects of palmitate were significantly attenuated by GLP1 co-treatment. However, the anti-apoptotic effects of GLP1 were markedly abolished when b-catenin was silenced with a specific short hairpin RNA. Furthermore, analysis of the upstream molecules and mechanisms responsible for GLP1-associated cardiac protection revealed that GLP1 restored the decreased phosphorylation of protein kinase B (Akt) and glycogen synthase kinase-3b (GSK3b) in palmitate-stimulated cardiomyocytes. In contrast, inhibition of Akt with an Akt-specific inhibitor MK2206 or blockade of GLP1 receptor (GLP1R) with a competitive antagonist exendin-(9-39) significantly abrogated the GLP1-mediated activation of GSK3b/b-catenin signalling, leading to increased apoptosis in palmitate-stressed cardiomyocytes. Collectively, our results demonstrated for the first time that the attenuated b-catenin signalling may contribute to palmitate-induced cardiomyocyte apoptosis, while GLP1 can protect cardiomyocytes from palmitate-induced apoptosis through activation of GLP1R/Akt/GSK3b-mediated b-catenin signalling.
| S-EPMC4621609 | biostudies-literature
Project description:BackgroundDespite current advances in gastric cancer treatment, disease metastasis and chemo-resistance remain as major hurdles against better overall prognosis. Previous studies indicated that IGHG1 as well as -Catenin serve as important regulators of tumor cellular malignancy. Therefore, understanding detailed molecular mechanism and identifying druggable target will be of great potentials in future therapeutic development.MethodsSurgical tissues and gastric cancer cell lines were retrieved to evaluate IGHG1 expression for patients with or without lymph node/distal organ metastasis. Functional assays including CCK8 assay, Edu assay, sphere formation assay and transwell assay, wound healing assay, etc. were subsequently performed to evaluate the impact of IGHG1/-catenin axis on tumor cell proliferation, migration and chemo-resistance.ResultsGastric cancer tissues and tumor cell lines demonstrated significantly higher level of IGHG1. Functional study further demonstrated that IGHG1 promoted proliferative and migration as well as chemo-resistance of gastric cancer tumor cells. Further experiments indicated that IGHG1 activated AKT/GSK-3/-Catenin axis, which played crucial role in regulation of proliferative and chemo-resistance of gastric cancer cells.ConclusionThis study provided novel evidences that IGHG1 acted as oncogene by promotion of gastric cancer cellular proliferation, migration and chemo-resistance. Our research further suggested that IGHG1/AKT/GSK-3β/β-Catenin axis acted as novel pathway which regulated gastric cancer cellular malignant behavior. Our research might inspire future therapy development to promote overall prognosis of gastric cancer patients.
| S-EPMC8314571 | biostudies-literature
Project description:Template-activating factor Iβ (TAF-Iβ) has been associated with numerous pathophysiological processes and has been reported as an oncogene responsible for the regulation of important signaling pathways in various types of solid tumor; however, few studies have investigated the role of TAF-Iβ in leukemia. The present study reported the upregulated expression of TAF-Iβ in 36 patients with acute leukemia and six leukemic cell lines. In addition, TAF-Iβ-knockdown (KD) cells were generated via RNA interference. TAF-Iβ KD not only inhibited the proliferation of leukemia cells but also induced apoptosis. Furthermore, it was revealed that the mechanism underlying these effects may be associated with the upregulation of protein phosphatase type 2A and inhibition of the protein kinase B/glycogen synthase kinase-3β signaling pathway. Collectively, the findings demonstrated that TAF-Iβ serves an important role in various types of leukemia and may be considered as a potential therapeutic target for the treatment of leukemia.
| S-EPMC6781801 | biostudies-other
Project description:miRNAs have been implicated in processing of cardiac hypoxia/reoxygenation (H/R)-induced injury. Recent studies demonstrated that miR-19a might provide a potential cardioprotective effect on myocardial disease. However, the effect of miR-19a in regulating myocardial ischemic injury has not been previously addressed. The present study was to investigate the effect of miR-19a on myocardial ischemic injury and identified the potential molecular mechanisms involved. Using the H/R model of rat cardiomyocytes H9C2 in vitro, we found that miR-19a was in low expression in H9C2 cells after H/R treatment and H/R dramatically decreased cardiomyocyte viability, and increased lactate dehydrogenase (LDH) release and cardiomyocyte apoptosis, which were attenuated by co-transfection with miR-19a mimic. Dual-luciferase reporter assay and Western blotting assay revealed that PTEN was a direct target gene of miR-19a, and miR-19a suppressed the expression of PTEN via binding to its 3'-UTR. We further identified that overexpression of miR-19a inhibited the expression of PTEN at the mRNA and protein levels. Moreover, PTEN was highly expressed in H/R H9C2 cells and the apoptosis induced by H/R was associated with the increase in PTEN expression. Importantly, miR-19a mimic significantly increased p-Akt levels under H/R. In conclusion, our findings indicate that miR-19a could protect against H/R-induced cardiomyocyte apoptosis by inhibiting PTEN /PI3K/p-Akt signaling pathway.
| S-EPMC5715126 | biostudies-literature
Project description:Materials and Methods:The petroleum ether (petrol), dichloromethane (CH2Cl2), ethyl acetate (EtOAc), and n-butyl alcohol (n-BuOH) fractions were isolated from alcohol extracts of D. moldavica L. Total phenolic and flavonoid contents and in vitro antioxidant activities of different fractions were evaluated. H9c2 cells were then treated with D. moldavica L. extracts before challenging with H2O2. Cell viability was determined by colorimetric assay, and ELISA was used to measure the levels of lactate dehydrogenase (LDH), malondialdehyde (MDA), and superoxide dismutase (SOD). Apoptosis levels and mitochondrial membrane potential were measured by flow cytometry. The expressions of cell apoptosis regulatory proteins caspase-3, Bax, and Bcl-2 were determined by western blotting. Results:Our results demonstrated that the EtOAc fraction from D. moldavica L. ethanol extract, which is rich in phenolic and flavonoid active constituents, had the strongest free radical scavenging activity. Additionally, this fraction increased H2O2-induced reduction in cell viability, SOD activity, and mitochondrial membrane potential. It also reduced H2O2-induced elevation in ROS production, contents of LDH and MDA, and H9c2 apoptosis. We further found that the EtOAc fraction increased Bcl-2 expression, while it decreased caspase-3 and Bax expressions induced by H2O2 in H9c2 cells. Conclusions:Our data revealed that the EtOAc fraction from D. moldavica L. ethanol extract ameliorates H2O2-induced cardiotoxicity via antiapoptotic and antioxidant mechanisms.
| S-EPMC7222556 | biostudies-literature