OBJECTIVETo explore miRNA expression change of differentiation of mice marrow mesenchymal stem cells (MSCs) into adipocytes, which lay the foundation for further studies on molecular mechanism of miRNA regulating the differentiation of MSCs into adipocytes.

METHODSC57BL/6 mice MSCs were isolated, cultured through the whole bone marrow method, amplified by the differential adherent method. Cell growth was observed by morphology and the expression of superficial antigen CD29, CD44, CD34 were detected through immunohistochemistry. MSCs was induced to differentiation into adipocytes with adipocyte differentiation medium, and adipogenic differentiation of MSCs was analyzed by oil Red O staining. MicroRNA microarray was used to investigate the differentially expressed miRNAs in MSCs and adipocytes.

RESULTS(1) The fifth passage of MSCs had high purity under an inverted m icroscope. Immunohistochemistry staining showed that CD29, CD44 were positive and CD34 was negative in more than 90% MSCs. There were a large number of lipid droplets in cytoplasm after MSCs were induced with adipocyte differentiation medium, Oil O staining was positive. (2) The microarray experiment showed that 75 differentially expressed miRNAs were obtained in adipocytes compared with MSCs, 20 up-regulated and 55 down-regulated miRNAs were observed among them.

CONCLUSIONThere was a expression change of miRNA of differentiation of MSCs into adipocytes, some miRNAs might play important roles in MSCs adipogenic differentiation.