title: Regulation of BMP2-induced intracellular calcium increases in osteoblasts.
abstract: Although bone morphogenetic protein-2 (BMP2) is a well-characterized regulator that stimulates osteoblast differentiation, little is known about how it regulates intracellular Ca2+signaling. In this study, intracellular Ca2+concentration ([Ca2+]i) upon BMP2 application, focal adhesion kinase (FAK) and Src activities were measured in the MC3T3-E1 osteoblast cell line using fluorescence resonance energy transfer-based biosensors. Increase in [Ca2+]i, FAK, and Src activities were observed during BMP2 stimulation. The removal of extracellular calcium, the application of membrane channel inhibitors streptomycin or nifedipine, the FAK inhibitor PF-573228 (PF228), and the alkaline phosphatase (ALP) siRNA all blocked the BMP2-stimulated [Ca2+]iincrease, while the Src inhibitor PP1 did not. In contrast, a gentle decrease of endoplasmic reticulum calcium concentration was found after BMP2 stimulation, which could be blocked by both streptomycin and PP1. Further experiments revealed that BMP2-induced FAK activation could not be inhibited by PP1, ALP siRNA or the calcium channel inhibitor nifedipine. PF228, but not PP1 or calcium channel inhibitors, suppressed ALP elevation resulting from BMP2 stimulation. Therefore, our results suggest that BMP2 can increase [Ca2+]ithrough extracellular calcium influx regulated by FAK and ALP and can deplete ER calcium through Src signaling simultaneously. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:1725-1733, 2016.
authors.affiliation: Institute of Biomedical Engineering, Chongqing University of Science and Technology, Chongqing, 401331, People's Republic of China.
authors.forename: Wenfeng
authors.initials: W
authors.lastname: Xu
authors.affiliation: Department of Biomedical Engineering, Dalian University of Technology, Dalian, Liaoning, 116024, People's Republic of China.
authors.forename: Bo
authors.initials: B
authors.lastname: Liu
authors.affiliation: Institute of Biomedical Engineering, Chongqing University of Science and Technology, Chongqing, 401331, People's Republic of China.
authors.forename: Xue
authors.initials: X
authors.lastname: Liu
authors.affiliation: Biosystems and Biomaterials Division, National Institute of Standards and Technology (NIST), Gaithersburg, 20899, Maryland.
authors.forename: Martin Y M
authors.initials: MY
authors.lastname: Chiang
authors.affiliation: Institute of Biomedical Engineering, Chongqing University of Science and Technology, Chongqing, 401331, People's Republic of China.
authors.forename: Bo
authors.initials: B
authors.lastname: Li
authors.affiliation: Bioengineering College, Chongqing University, Chongqing, 400044, People's Republic of China.
authors.forename: Zichen
authors.initials: Z
authors.lastname: Xu
authors.affiliation: Institute of Biomedical Engineering, Chongqing University of Science and Technology, Chongqing, 401331, People's Republic of China. zxc_228@163.com.
authors.forename: Xiaoling
authors.initials: X
authors.lastname: Liao
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D055396:Bone Morphogenetic Protein 2 / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism*; D002460:Cell Line; D031541:Fluorescence Resonance Energy Transfer; D051416:Focal Adhesion Protein-Tyrosine Kinases / Q000378:metabolism; D051379:Mice; D010006:Osteoblasts / Q000378:metabolism*; D019061:src-Family Kinases / Q000378:metabolism
chemical_list: C525719:Bmp2 protein, mouse; D055396:Bone Morphogenetic Protein 2; D051416:Focal Adhesion Protein-Tyrosine Kinases; D019061:src-Family Kinases; D000469:Alkaline Phosphatase; D002118:Calcium
keywords: BMP2; calcium; fluorescence resonance energy transfer; osteoblasts; signal transduction mediators