Effect of acetylation modification on microenvironment adaptability of mesenchymal stem cells

Objective To study the changes of acetylation level of smooth muscle marker gene after the differentiation of bone marrow mesenchymal stem cells (BMSCs) in smooth muscle microenvironment, and explore the role and mechanism of histone acetylation modification in the differentiation of stem cells. Methods BMSCs and bladder smooth muscle cells (BSMCs) were cultured in vitro. The third generation BMSCs of the same batch were selected, and BMSCs co-cultured with BSMCs for 3 days were set as the experimental group and the BMSCs without co-culture as the control group. RT-PCR was performed to compare the expression abundance between the two groups of α-smooth muscle actin (α-SMA), calponin and smooth muscle myosin heavy chain (SM-MHC) in BMSCs. Ultrasound of power 80%, 20 times, 0.5 s and 8 cycles were used to break the BMSCs DNA of both experimental and control group. Antibody H3K9 was used to bind to the specific acetylation sites. The acetylation site genes of histone in BMSCs were precipitated by chromatin immunoprecipitation (ChIP). The genes obtained was amplified by adaptor PCR. The expression levels of the three kinds of target genes (α-SMA, calponin, SM-MHC) were detected by Real-time PCR. Results RT-PCR showed that the expression levels of mRNA of smooth muscle marker genes (α-SMA, calponin, SM-MHC) in BMSCs were significantly higher in experimental group than in control group (0.176±0.003 vs. 0.070±0.002; 0.079±0.002 vs. 0.051±0.003 and 0.091±0.004 vs. 0.034±0.001, respectively) with significant differences. Test results of spectrophotometer showed that the amount of DNA obtained by precipitation of H3K9 acetylated antibody was higher than that of IgG antibody, and was higher in experimental group than in control group (P