ABSTRACT
Aim To investigate whether resveratrol (Resveratrol, Res) induces cardiomyocyte protection by increasing intracellular zinc ion and its possible signal mechanism. Methods H9c2 cells were routinely cultured and 2-deoxyglucose (2-DG) was used to establish an endoplasmic reticulum stress (ERS) model. The experiment was randomly divided into control group, 2-DG group, Res +2-DG group, TPEN + Res + 2-DG group and 3-MA + Res +2-DG group. Cell viability was detected by MTT and CCK-8; the expression levels of ERS molecular chaperone proteins glucose-regulated protein 78 (GRP78), glucose-regulated protein 94 (GRP94) and autophagy proteins LC3 II / I, p62 and p-AMPK were detected by Western blot; the expression of LC3 protein was measured by cellular immunofluorescence; the mitochondrial membrane potential (Aijjm) and the intracellular zinc ion level were measured by laser scanning confocal microscope. Results Compared with the control group, 2-DG reduced cell activity and resveratrol inhibited the changes caused by 2-DG, which was reversed by zinc chelator TPEN. 2-DG increased GRP78 and GRP94 expression and resveratrol inhibited the protein changes caused by 2-DG, which was reversed by TPEN. 2-DG increased the expression of LC3 II / I, p-AMPK and decreased the expression of p62, and resveratrol promoted the effect of 2-DG. 2-DG increased the fluorescence intensity of LC3, and resveratrol enhanced the effect of 2-DG, which was reversed by TPEN and 3-MA. 2-DG reduced the red fluorescence intensity of mitochondrial TMRE and green fluorescence intensity of intracellular zinc ions, and resveratrol inhibited these changes caused by 2-DG, which was also reversed by TPEN and 3-MA. The above differences were all statistically significant (P < 0. 05). Conclusion Resveratrol increases intracellular zinc to promote ERS-induced autophagy and prevent the mPTP opening in H9c2 cardiac cells.
ABSTRACT
The present study is aimed to investigate the toxic effects of andrographolide (Andro) on hepatoma cells and elucidate its preliminary mechanisms. After cells were treated with different concentrations of Andro (0-50 micromol x L(-1)) for 24 h, cell viability was evaluated with 3-(4,5-dimethylthiazol-2-yl) 2,5-diphenyltetrazolium bromide (MTT) assay. Furthermore, after hepatoma cells (Hep3B and HepG2) were treated with different concentrations of Andro (0-30 micromol x L(-1)) for 14 d, the number of colony formation was accounted under microscope. Cell cycle related proteins such as Cdc-2, phosphorylated-Cdc-2, Cyclin B and Cyclin D1 were detected with Western blotting assay and the cell cycle was analyzed by flow cytometry using propidium iodide staining. MTT results showed that Andro induced growth inhibition of hepatoma cells in a concentration-dependent manner but had no significant effects on human normal liver L-02 cells. Andro dramatically decreased the colony formation of hepatoma cells in the concentration-dependent manner. Moreover, Andro induced a decrease of Hep3B cells at the G0-G1 phase and a concomitant accumulation of cells at G2-M phase. At the molecular level, Western blotting results showed that Andro decreased the expression of Cdc-2, phosphorylated-Cdc-2, Cyclin D1 and Cyclin B proteins in a time-dependent manner, which are all cell cycle related proteins. Taken together, the results demonstrated that Andro specifically inhibited the growth of hepatoma cells and cellular cell cycle related proteins were possibly involved in this process.