The Effect Of BMP2/7 Heterodimer On The Cocultured Osteoblast And Osteoclast

Objective Bone morphogenetic proteins homodimers a group of dimeric disulfide-linked polypeptide growth factors under transforming growth factor-? superfamily,are one of the paramount cytokines in promoting bone regeneration,has already been uesd in the clinic.BMP2/7 heterodimers were exhibited to be more potent than and thus were potential substitutes for BMP2 homodimers.BMP2 can not only promote the osteoblast,but also can affect the function of the osteoclasts.We,hereby,explored the effects of BMP2/7 heterodimer in the co-culture of osteoblast and osteoclasts system in comparison to BMP2 homodimers.Methods To compare the effects of BMP2/7 heterodimer versus BMP2 homodimer in the co-culture system.Cell proliferation was examined by fluorometric quantification.Alkaline phosphatase(ALP)activities were investigated with a colorimetric assay kit.Osteocalcin(OCN)expressions were determined using an enzyme-linked immunosorbent assay(ELISA)kit.The gene expressions of ALP and OCN were detected by real-time RT-PCR analysis and normalized by ?-actin gene expression.Cell matrix mineralization was evaluated by alizarin red staining.BMP2/7 heterodimer and BMP2 homodime were performed on osteoblastogenesis of RANKL(50ng/ml)-stimulated osteoclast cells.The relative gene expressions of calcitonin receptor(calcr),capthesin K and TRAP(acp5).Results BMP2/7 heterodimer induced the biological activities of the process of osteoblast as homodimers.The maximum levels in chemotaxis induced by BMP2/7 were significantly higher than the respective BMP homodimers in the 3 weeks,furthermore BMP2/7 in 3 weeks were higher than the 4 weeks,However,ALP activity and OCN expression induced by BMP2/7 heterodimer were higher than those induced by the homodimers.Refer to relative gene expression,BMP2/7 and BMP2 had no significant effects.Interestingly,calcr expression decreased under the stimulation of BMP,especially at BMP2.Cathepsin K expression decreased significantly under the stimulation of BMP2/7.Conclusion BMP2/7 can induce osteogenesis effects in co-culture system of osteoblast and osteoclast,and The effect is higher than the BMP2 homodime.The characteristics made BMP2/7 to be the substitute of BMP2 applied to bone induction in the clinic.BMP2/7,BMP2 can affect the osteoclast induced by RANKL.BMP2/7 can induce osteoclasts,but the effect was slightly lower than that of BMP2.So BMP2/7 can stimulate the osteogenesis,at the same time,can reduce the bone absorption.