Yamada Takayuki, Ezura Yoichi, Hayata Tadayoshi, Moriya Shuichi, Shirakawa Jumpei, Notomi Takuya, Arayal Smriti, Kawasaki Makiri, Izu Yayoi, Harada Kiyoshi, Noda Masaki
Department of Molecular Pharmacology, Medical Research Institute, Tokyo Medical and Dental University, Tokyo, Japan; Department of Oral and Maxillofacial Surgery, Tokyo Medical and Dental University, Tokyo, Japan; Global COE Program, Tokyo Medical and Dental University, Tokyo, Japan.
J Cell Biochem. 2015 Jun;116(6):1144-52. doi: 10.1002/jcb.25071.
β adrenergic stimulation suppresses bone formation in vivo while its actions in osteoblastic differentiation are still incompletely understood. We therefore examined the effects of β2 adrenergic stimulation on osteoblast-like MC3T3-E1 cells focusing on BMP-induced alkaline phosphatase expression. Morphologically, isoproterenol treatment suppresses BMP-induced increase in the numbers of alkaline phosphatase-positive small foci in the cultures of MC3T3-E1 cells. Biochemically, isoproterenol treatment suppresses BMP-induced enzymatic activity of alkaline phosphatase in a dose-dependent manner. Isoproterenol suppression of alkaline phosphatase activity is observed even when the cells are treated with high concentrations of BMP. With respect to cell density, isoproterenol treatment tends to suppress BMP-induced increase in alkaline phosphatase expression more in osteoblasts cultured at higher cell density. In terms of treatment protocol, continuous isoproterenol treatment is compared to cyclic treatment. Continuous isoproterenol treatment is more suppressive against BMP-induced increase in alkaline phosphatase expression than cyclic regimen. At molecular level, isoproterenol treatment suppresses BMP-induced enhancement of alkaline phosphatase mRNA expression. Regarding the mode of isoproterenol action, isoproterenol suppresses BMP-induced BRE-luciferase activity. These data indicate that isoproterenol regulates BMP-induced alkaline phosphatase expression in osteoblast-like MC3T3E1 cells.
β肾上腺素能刺激在体内会抑制骨形成，但其在成骨细胞分化中的作用仍未完全明确。因此，我们研究了β2肾上腺素能刺激对成骨样MC3T3-E1细胞的影响，重点关注骨形态发生蛋白（BMP）诱导的碱性磷酸酶表达。在形态学上，异丙肾上腺素处理可抑制BMP诱导的MC3T3-E1细胞培养物中碱性磷酸酶阳性小灶数量的增加。在生物化学方面，异丙肾上腺素处理以剂量依赖的方式抑制BMP诱导的碱性磷酸酶的酶活性。即使细胞用高浓度的BMP处理，也能观察到异丙肾上腺素对碱性磷酸酶活性的抑制作用。就细胞密度而言，在较高细胞密度下培养的成骨细胞中，异丙肾上腺素处理往往更能抑制BMP诱导的碱性磷酸酶表达的增加。在处理方案方面，将异丙肾上腺素持续处理与循环处理进行了比较。与循环处理方案相比，异丙肾上腺素持续处理对BMP诱导的碱性磷酸酶表达增加具有更强的抑制作用。在分子水平上，异丙肾上腺素处理可抑制BMP诱导的碱性磷酸酶mRNA表达的增强。关于异丙肾上腺素的作用方式，异丙肾上腺素可抑制BMP诱导的BRE-荧光素酶活性。这些数据表明，异丙肾上腺素可调节BMP诱导的成骨样MC3T3E1细胞中碱性磷酸酶的表达。
