BMP-4 increasesactivin Agene 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.

Activin A Promotes Osteoblastic Differentiation of Human Preosteoblasts through the ALK1-Smad1/5/9 Pathway

“…Previous studies demonstrated that application of activin A in the parietal bone led to upregulation of bone formation in newborn rats [39] and mice [40]. An in vitro study demonstrated that activin A contributed to osteogenesis of mouse embryonic stem cells [41] and promoted osteoblastic differentiation of murine bone marrow cells [38] and murine myoblasts [42]. Consistent with these reports, our results demonstrated that activin A was expressed in Saos2 cells and promoted osteoblastic differentiation of Saos2 cells.…”

Activin A in Mammalian Physiology

“…The reason for this temporal-and spatial-dependent pattern of expression is still unclear; however, these are intense periods of hypertrophic chondrogenesis and bone mineralization. Activin A is involved in the early embryonic processes of mesodermal formation (7,8,18) and in the differentiation of mesenchymal progenitor cells into chondrogenic and osteogenic fates (50,106). In addition, activin A signaling controls digit skeletogenesis (281), early development of jaw, teeth, and palate (120,271), and embryonic left/right patterning (309).…”

Pluripotent stem cells as a source of osteoblasts for bone tissue regeneration

“…Several recent studies have focused on differentiating both ESCs and iPSCs into osteoblasts [8][9][10]. ESCs and iPSCs can be differentiated to the osteoblast lineage by first forming embryoid bodies (EBs), in which mesoderm lineage cells differentiate to osteoblast lineage cells under osteogenic factors including ascorbic acid, ßglycerophosphate, and dexamethasone [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27]. ESCs and iPSCs can also be differentiated to osteoblast lineage cells through monolayer culture without first forming suspended EBs [28][29][30][31][32][33][34][35].…”