[Adiponectin reduces apoptosis of macrophages induced by cobalt chloride and its mechanism]

Objective To investigate the protective effects and mechanism of adiponectin (APN) on RAW264.7 macrophages under cell model of hypoxia established by CoCl₂. Methods Cells were treated with CoCl₂ (100 μmol/L) and different concentrations of APN (0.5, 1, 2 μg/mL APN, pretreated for 2 hours firstly, and treated with CoCl₂ in a dose of 100 μmol/L). The cells' vitality in each group was detected by CCK-8 assay. The distribution of caspase-3, as well as the influences of CoCl₂ and APN on the expression of caspase-3 was detected by immunofluorescence technique. Apoptotic rates of cells in all groups were analyzed by flow cytometry. The levels of SOD and MDA in each group were measured by spectrophotometer. The expressions of Bcl2, BAX, cleaved caspase-3 and HIF-1α of cells in each group were observed by Western blot analysis. Results Compared with CoCl₂ group, pretreatment with APN could increase cell vitality, decrease apoptosis, increase the level of SOD, and decrease the level of MDA. Immunofluorescence results revealed that caspase-3 in each group was mainly distributed in the cell membranes, and compared with CoCl₂ group, the expression of Bcl2 was evidently increased, BAX, cleaved caspase-3 and HIF-1α were decreased after being pretreated with APN. Conclusion APN could decrease CoCl₂-induced apoptosis in RAW264.7 cells, which may occur via enhancing the intracellular antioxidant activity, and by upregulation of Bcl2, downregulation of BAX, cleaved caspase-3 and HIF-1α.