Beyond osteogenesis: an in vitro comparison of the potentials of six bone morphogenetic proteins

Abstract

Bone morphogenetic proteins (BMPs) other than the clinically available BMP-2 and BMP-7 may be useful for improving fracture healing through both increasing osteogenesis and creating a favorable healing environment by altering cytokine release by endogenous cells. Given the spectrum of potential applications for BMPs, the objective of this study was to evaluate various BMPs under a variety of conditions to provide further insight into their therapeutic capabilities. The alkaline phosphatase (ALP) activity of both C2C12 and human adipose-derived stem cells (hASCs) was measured after exposure of increasing doses of recombinant human BMP-2, -4, -5, -6, -7, or -9 for 3 and 7 days. BMPs-2, -4, -5, -6, -7, and -9 were compared in terms of their ability to affect the release of stromal derived factor-1 (SDF-1), vascular endothelial growth factor (VEGF), and basic fibroblast growth factor (b-FGF) from human bone marrow stromal cells (hBMSCs). Gene expression of ALP, osteocalcin, SDF-1, VEGF, and b-FGF following shRNA-mediated knockdown of BMP-2 and BMP-6 in hBMSCs or human osteoblasts under osteogenic differentiation conditions was also evaluated. Collectively, BMPs-6 and -9 produced the greatest osteogenic differentiation of C2C12 and hASCs as determined by ALP. The hBMSC secretion of SDF-1 was most affected by BMP-5, VEGF by BMP-4, and b-FGF by BMP-2. The knockdown of BMP-2 in BMSCs had no effect on any of the genes measured whereas BMP-6 knockdown in hBMSCs caused a significant increase in VEGF gene expression. BMP-2 and BMP-6 knockdown in human osteoblasts caused significant increases in VEGF gene expression and trends toward decreases in osteocalcin expression. These findings support efforts to study other BMPs as potential bone graft supplements, and to consider combined BMP delivery for promotion of multiple aspects of fracture healing.

Involvement of the phosphoinositide 3‐kinase/Akt signaling pathway in bone morphogenetic protein 9‐stimulated osteogenic differentiation and stromal cell‐derived factor 1 production in human periodontal ligament fibroblasts

“… demonstrated that exogenous BMP‐9 up‐regulated expression of SDF‐1‐alpha by human endothelial cells and Rivera et al . reported that exogenous BMPs, including BMP‐4, ‐6, and ‐9, increased SDF‐1 production in human bone marrow stromal cells. However, Liu et al .…”

“…In our study, rhBMP-9 modestly enhanced the level of SDF1a mRNA and the levels of SDF-1 protein in PDLFs cultured in the osteogenic medium, and the rhBMP-9-stimulated SDF-1 production was suppressed by LY294002. YOUNG et al (23) demonstrated that exogenous BMP-9 up-regulated expression of SDF-1-alpha by human endothelial cells and RIVERA et al (10) reported that exogenous BMPs, including BMP-4, -6, and -9, increased SDF-1 production in human bone marrow stromal cells. However, LIU et al (24) reported a reduction of SDF1 mRNA in C3H10T1/2 cells following delivery of BMP-9 by an adenoviral vector.…”

An NIR‐II Fluorescence/Dual Bioluminescence Multiplexed Imaging for In Vivo Visualizing the Location, Survival, and Differentiation of Transplanted Stem Cells

“…These results in combination with the micro‐CT and H&E histological staining conclude that a large amount of new bones has been formed around the down edge of the collagen scaffold after 30 days of hMSCs' transplantation (Figure A,B), evidencing that the transplanted hMSCs can facilitate bone formation around their habitat via osteogenic differentiation. The osteogenic differentiation of transplanted hMSCs can also be distinctly improved by BMP‐2 treatment through BMP signaling pathway . As shown in Figure B, the expression of the transcriptional factors and transcriptional co‐activators (Runx2 and Osterix) was significantly upregulated after BMP‐2 treatment.…”

“…As shown in Figure C, the expression of stromal cell–derived factor‐1α (SDF‐1α), basic fibroblast growth factor (FGF), and BMP‐2 genes was highly active in hMSCs. It is known that the SDF‐1α is a vital chemokine for regulating stem cell migration and homing, the FGF is a key factor involved in cell proliferation, and the BMP‐2 is a crucial factor for osteogenic differentiation of cells . Thus, these cytokines excreted by the transplanted hMSCs helped to recruit endogenous osteoblasts at the bone defect site and promoted bone regeneration.…”

Cellular and Animal Models for the Identification of Osteoporosis Determinants Increasing Vertebral Compression Fractures Risk

“…In addition, there are several other murine cell lines that, under appropriate stimuli, can be induced to differentiate into osteoblasts in vitro. For instance, the mouse myoblast cells C2C12 differentiate along the osteogenic lineage in presence of BMPs and the embryo-derived fibroblasts NIH3T3 adopt an osteoblast-like phenotype when treated with 1α,25-dihydroxyvitamin D(3) and dexamethasone [52][53][54].…”