BMP-4 increases activin A gene expression during osteogenic differentiation of mouse embryonic stem cells

Abstract

Activin A is a growth factor released by mature osteoblasts that has a critical effect on bone formation. We investigated the effect of bone morphogenetic protein (BMP)-4 on activin A gene expression during in vitro osteogenic differentiation of mouse embryonic stem (ES) cells. Embryoid bodies were cultured in retinoic acid (RA) for three days and then without RA for two days. Seeded cells received osteogenic medium with β-glycerophosphate, L-ascorbic acid 2-phosphate and dexamethasone during 19 days, with or without BMP-4. Six independent experiments were carried out. Real-time PCR was used to detect gene expression of activin A, Oct-4, Nanog, osteocalcin, RUNX2 and bone alkaline phosphatase. Immunofluorescence was used to co-localize activin A with the undifferentiation marker stage-specific embryonic antigen 1. Cells treated with BMP-4 had an increased gene expression of activin A, osteocalcin and bone alkaline phosphatase (p < 0.05). In conclusion, BMP-4 increases activin A gene expression during mouse ES cell differentiation into bone precursors.

• BMP-4
• differentiation
• embryonic stem cells
• osteogenesis
• osteogenic precursors

Declaration of interest

The authors report no conflicts of interest. This study was supported by Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) through the Brazilian National Institute of Hormones and Women's Health (grant # 573747/2008-3), Foundation for Research Support of the State of Minas Gerais (Fundação de Amparo à Pesquisa do Estado de Minas Gerais, PEE-00672-13), Postgraduate Support Programme (PROAP – CAPES) and Women’s Health Postgraduate Program, Faculty of Medicine, Federal University of Minas Gerais.