Voltage-gated K+ channels in adipogenic differentiation of bone marrow-derived human mesenchymal stem cells

摘要

Aim:To determine the presence of voltage-gated K+ (Kv) channels in bone marrow-derived human mesenchymal stem cells (hMSCs)and their impact on differentiation of hMSCs into adipocytes.Methods:For adipogenic differentiation,hMSCs were cultured in adipogenic medium for 22 d.The degrees of adipogenic differentiation were examined using Western blot,Oil Red O staining and Alamar assay.The expression levels of Kv channel subunits Kv1.1,Kv1.2,Kv1.3,Kv1.4,Kv2.1,Kv3.1,Kv3.3,Kv4.2,Kv4.3,and Kv9.3 in the cells were detected using RT-PCR and Western blot analysis.Results:The expression levels of Kv2.1 and Kv3.3 subunits were markedly increased on d 16 and 22.In contrast,the expression levels of other Kv channel subunits,including Kv1.1,Kv1.2,Kv1.3,Kv1.4,Kv4.2,Kv4.3,and Kv9.3,were decreased as undifferentiated hMSCs differentiated into adipocytes.Addition of the Kv channel blocker tetraethylammonium (TEA,10 mmol/L) into the adipogenic medium for 6 or 12 d caused a significant decrease,although not complete,in lipid droplet formation and adipocyte fatty acid-binding protein 2 (aP2) expressions.Addition of the selective Kv2.1 channel blocker guangxitoxin (GxTX-1,40 nmol/L) into the adipogenic medium for 21 d also suppressed adipogenic differentiation of the cells.Conclusion:The results demonstrate that subsets of Kv channels including Kv2.1 and Kv3.3 may play an important role in the differentiation of hMSCs into adipocytes.