Upregulation of proteasome activity by 18α-GA promotes proliferation of late-passage BMSCs in vitro / 中国病理生理杂志

ABSTRACT

AIM:To investigate the effect of 18 alpha-glycyrrhetinic acid (18α-GA) on delaying the senescent progress and promoting the proliferation in late-passage bone marrow mesenchymal stem cells ( BMSCs ) .METHODS:Late-passage BMSCs were incubated with 2.0 mg /L 18α-GA or the same volume of DMSO for 30 d, and the cells were harvested to determine the proteasome activity .The expression of senescence-related proteins p53, p21 and p16 was detec-ted by senescence-associated β-galactosidase ( SA-β-Gal) staining and Western blot .The cell proliferation , the expression level of cell cycle-related proteins and cell cycle distribution of the cells were measured by CCK -8 assay, BrdU incorpora-tion, Western blot and flow cytometry.RESULTS:Compared with DMSO group, the proteasome activity in 18α-GA group increased significantly by about 0.2 times (P<0.01).SA-β-Gal-positive cells in 18α-GA group decreased, and cell stai-ning was lighter.The contents of p53 and p21 in 18α-GA group were decreased (P<0.05).The results of CCK-8 assay showed that the A value in 18α-GA group was 0.3 times higher than that in DMSO group (P<0.01).BrdU incorporation showed the increased proliferation in 18α-GA group compared with DMSO group ( P<0.05).The cells in G1 phase in 18α-GA group decreased significantly compared with DMSO group , while the cells in S phase increased significantly ( P<0.05).The expression level of cyclin D1 in 18α-GA group was 2.8 times higher than that in DMSO group (P<0.01), and the CDK4 level was 1.4 times higher than that in DMSO group (P<0.05).CONCLUSION:Activation of the pro-teasome activity by 18α-GA delays the aging process in the BMSCs and promotes the cell proliferation via up -regulation of the cell cycle-related proteins .