Molecular mechanism of sulforaphane promoting the differentiation of bone marrow stem cells into osteoblasts / 局解手术学杂志

ABSTRACT

Objective To investigate the molecular mechanism of sulforaphane(Sul)promoting bone marrow stem cells(BMSCs)differentiating into osteoblasts.Methods BMSCs were divided into the control group(without any treatment),induction group(induction of osteogenic differentiation),and induction+Sul group(induction of osteogenic differentiation with the addition of 40 μmol/L of Sul).The adenovirus-shRNA-Mock,-shRNA-TET1,-shRNA-TET2,and-shRNA-TET3 were transfected into BMSCs as the shRNA-Mock group,shRNA-TET1 group,shRNA-TET2 group,and shRNA-TET3 group.BMSCs were cultured in cell culture medium containing osteogenic differentiation induction medium and 40 μmol/L of Sul,and then transfected with adenovirus-shRNA-TET1,-shRNA-TET2,-shRNA-TET3,and-shRNA-Mock as the induction+Sul+shRNA-TET1 group,induction+Sul+shRNA-TET2 group,induction+Sul+shRNA-TET3 group,and induction +Sul+shRNA-Mock group.The mRNA and protein expression levels of Runx2 after BMSCs differentiated into osteoblasts were determined by qPCR and Western blot.The DNA content of Runx2 promoter region bound to Histone H3 after BMSCs differentiated into osteoblasts was determined by chromatin immunocoprecipitation(ChIP).The methylation level of Runx2 promoter region of BMSCs differentiated into osteoblasts was determined by HpaⅡenzyme and MspⅠenzyme digestion combined with qPCR.The degree of BMSCs differentiated into osteoblasts was determined by alizarin red staining.Results Compared with the induction group,the mRNA and protein expression levels of Runx2 in the induction+Sul group were significantly increased(P<0.05);the content of DNA in the Runx2 promoter region bound to Histone H3 was increased(P<0.05),the methylation level of Runx2 promoter region was reduced(P<0.05),and the alizarin red staining score was elevated(P<0.05).Compared with the induction+Sul group,the content of DNA in the Runx2 promoter region bound to Histone H3 in the induction+Sul+shRNA-TET1 group was decreased(P<0.05),the methylation level of Runx2 promoter region was increased(P<0.05),and the alizarin red staining score was decreased(P<0.05).While there was no significant change among the induction+Sul+shRNA-TET2 group,induction+Sul+shRNA-TET3 group,induction+Sul+shRNA-Mock group(P>0.05).Conclusion Sul can promote the differentiation of BMSCs into osteoblasts through promoting DNA demethylation of Runx2 promoter region by TET1.