Melatonin inhibits adipogenic differentiation of bone marrow mesenchymal stem cells through retinoid-related orphan receptor alpha / 中国组织工程研究

ABSTRACT

BACKGROUND:Our previous studies have demonstrated that melatonin inhibits the adipogenic differentiation of bone marrow mesenchymal stem cels. However, the mechanism underlying the effect of melatonin on adipogenesis is stil unknown. OBJECTIVE:To determine whether melatonin can inhibit the adipogenesis of bone marrow mesenchymal stem cels through retinoid-related orphan receptor α. METHODS:Bone marrow mesenchymal stem cels were isolated and purified by density gradient centrifugation combined with cellattachment culture. The phenotype was investigated by flow cytometry. Then, cels were induced for adipogenic differentiation with melatonin, CGP52608 and normal adipose tissue, respectively. The levels of retinoid-related orphan receptor α mRNA and protein were investigated by real-time RT-PCR and western blot assay, respectively. Further, the effect of retinoid-related orphan receptor α on the dipogenic differentiation of bone marrow mesenchymal stem cels was investigated by CGP52608. RESULTS AND CONCLUSION:The primary isolated bone marrow mesenchymal stem cels were spindle-shaped fibroblast-like cels. These cels did not express hematopoietic stem cels markers CD34 and CD45; and highly expressed MSC markers CD29, CD44, and CD10. The result of RT-PCR demonstrated that melatonin nuclear receptor, retinoid-related orphan receptor α, was highly expressed in bone marrow mesenchymal stem cels and the expression of retinoid-related orphan receptor α was further enhanced by melatonin in a dose-dependent manner, which was confirmed at protein level by western blot assay. During adiogenesis, the expression of retinoid-related orphan receptor αmRNA was up-regulated in the early stage, but maintained at a low level in the mild-later stage. While the retinoid-related orphan receptor α was activated by agonist CGP52608, the adipogenic differentiation of bone marrow mesenchymal stem cels was inhibited, which was similar to the inhibitory effect of melatonin. Therefore, melatonin inhibited the adipogenic differentiation of bone marrow mesenchymal stem cels through retinoid-related orphan receptor α, suggesting that melatonin plays an important role in the differentiation of adipocytes.