Down-regulation of miR-221-3p/222-3p inhibits cell proliferation and promotes chondrogenic differentiation of human bone marrow mesenchymal stem cells / 中国组织工程研究

ABSTRACT

BACKGROUND:The use of mesenchymal stem cels in the field of tissue engineering for osteoarticular injury repair is a very promising tool since these cels are readily expandable and able to differentiate into chondrocytes. Abundant evidence suggests that microRNAs play critical roles in chondrogenic differentiation of mesenchymal stem cels. OBJECTIVE:To observe the chondrogenic effect of human bone marrow mesenchymal stem cels transfected with lentiviral vectors bearing miR-221-3p/222-3p inhibition, thereby provding new strategies for cartilage injury. METHODS: miRNA microarray technology was applied to detect microRNAs expression profiles at three different stages of chondrogenic differentiation induction after transforming growth factor-β3 treatment and verified by real-time fluorescence quantitative PCR (RT-qPCR). Human bone marrow mesenchymal stem cels were infected with lentivirus bearing miR-221-3p/222-3p inhibition. After co-suppressing the expression of miR-221/222-3p, cel counting kit-8 was used to determine the cel proliferation, the differentiation of bone marrow mesenchymal stem cels towards chondrocytes was verified by type II colagen protein expression through immunohistochemistry and glycosaminoglycan accumulation was also elevated by sarranine O staining. RT-PCR was used to detect type II colagen and aggrecan mRNA expression at 21 days of chondrogenic induction. RESULTS AND CONCLUSION: The expression of miR-221-3p/222-3p was inhibited after Lv-miR221-3p/222-3p inhibition co-transfected into bone marrow mesenchymal stem cels. microRNA microarray and RT-qPCR results showed that the expression of miR-221-3p/222-3p was declined significantly at the anaphase of chondrogenic differentiation. The expression levels of chondrogenic markers, Aggrecan and type II colagen were significantly increased in the miR-221-3p/222-3p inhibition group and cel proliferation was also inhibited significantly compared with non-transduced cels or transduced with the empty lentiviral vector group. miR-221-3p/222-3p knockdown in bone marrow mesenchymal stem cels could inhibit proliferation but promote chondrogenic differentiation of bone marrow mesenchymal stem cels.