Potential involvement of BMP receptor type IB activation in a synergistic effect of chondrogenic promotion between rhTGFβ3 and rhGDF5 or rhBMP7 in human mesenchymal stem cells

Abstract

Chondrogenic promotion by rhGDF5 with or without rhTGFbeta3 was studied in pellet culture of human mesenchymal stem cells (HMSCs). A synergy between rhGDF5 and rhTGFbeta3 was observed in promoting chondrogenesis. rhBMP2, rhBMP6, rhBMP7 and rhTGFbeta1 were further tested and showed the same effect. To explore the mechanism, the expression of TGFbetatype I and II receptors, ALK5, ALK2, ALK3, ALK6, TGFbetaRII, BMPRII, ActRII was studied. ALK6 showed increase by the rhTGFbeta1 or rhTGFbeta3 treatment. ALK6 protein expression also showed increase by rhTGFbeta3. rhTGFbeta1/rhTGFbeta3 induced ALK6 up-regulation was inhibited by SD-208, a TGFbeta type I receptor inhibitor. Chondrogenesis by rhTGFbetal/rhTGFbeta3 or the combination between rhTGFbetal/rhTGFbeta3 and rhGDF5 also was diminished by SD-208. SMAD1/5/8 phosphorylation in nascent human mesenchymal stem cells (HMSCs) was stimulated weakly by rhGDF5 but strongly by rhBMP7. The rhGDF5 stimulated SMAD1/5/8 phosphorylation was enhanced by rhTGFbetal/rhTGFbeta3 but inhibited by SD-208. The rhBMP7 stimulated SMAD1/5/8 phosphorylation did not show influence by rhTGFbeta3 and SD-208. Our results indicated the potential involvement of ALK6 activation by rhTGFbetas in the synergy between rhTGFbetas and rhBMPs.

The role of BMP‐7 in chondrogenic and osteogenic differentiation of human bone marrow multipotent mesenchymal stromal cells in vitro

“…The mechanism of BMP-7 enhancement for TGF-b3-mediated chondrogenic differentiation is not clear. It has been reported that the TGF-b type III receptor functions as a BMP cell surface receptor which binds to multiple members of the BMP subfamily including BMP-7 [Kirkbride et al, 2008], and TGFb3 mediates the upregulation of the type I BMP receptor, ALK6 [Xu et al, 2006] through which BMP-7 and other BMPs are known to signal [Yamashita et al, 1996]. Taken together, the recent advance suggests that mutual regulation or receptor activation may amplify and enhance the effects of TGF-b and BMPs.…”

“…Chondrogenic differentiation of BM MSCs can generally be induced by stimulation with all isoforms of TGF-b in serum-free medium at high cell density [Mackay et al, 1998;Pittenger et al, 1999]. However, previous reports have suggested that TGF-b alone may not be sufficient for chondrogenic induction, and that a combination of growth factors is necessary [Sekiya et al, 2001;Xu et al, 2006;Shen et al, 2008]. We present here that BMP-7, when supplemented in chondrogenic differentiation medium containing TGF-b3, enhanced the mRNA and/or protein expression of chondrogenic markers COL2A1, COL9A1, COL10A1, and SOX9, and increased extracellular matrix proteoglycan deposition.…”

Joint Cartilage Tissue Engineering and Pre-Clinical Safety and Efficacy Testing

“…BMP-2, and -7 have been shown to be the more chondrogenic of the BMPs in MSCs in vitro (Majumdar et al, 2001;Sekiya et al, 2005;Fan et al, 2010), and both have shown promising results in animal models (Badlani et al, 2009;Blaney Davidson et al, 2007b). The chondrogenic effect of BMP-7 is synergistically increased when used in combination with TGF-β (Xu et al, 2006;Kim and Im, 2009) or insulin-like growth factor (IGF)-1 (Loeser et al, 2003;Chubinskaya et al, 2007a). BMP-2 is also a strong inducer of osetogenesis and is used clinically for bone fusion (Tang et al, 2011;Hamilton et al, 2011), which needs to be taken into consideration if using BMP-2 for cartilage generation.…”

Tissue Engineering for Tissue and Organ Regeneration

“…BMP-2, and -7 have been shown to be the more chondrogenic of the BMPs in MSCs in vitro (Majumdar et al, 2001;Sekiya et al, 2005;Fan et al, 2010), and both have shown promising results in animal models (Badlani et al, 2009;Blaney Davidson et al, 2007b). The chondrogenic effect of BMP-7 is synergistically increased when used in combination with TGF-β (Xu et al, 2006;Kim and Im, 2009) or insulin-like growth factor (IGF)-1 (Loeser et al, 2003;Chubinskaya et al, 2007a). BMP-2 is also a strong inducer of osetogenesis and is used clinically for bone fusion (Tang et al, 2011;Hamilton et al, 2011), which needs to be taken into consideration if using BMP-2 for cartilage generation.…”