Torigoe Go, Nagao Mayu, Tanabe Natsuko, Manaka Soichiro, Kariya Taro, Kawato Takayuki, Sekino Jumpei, Kato Shunichiro, Maeno Masao, Suzuki Naoto, Shimizu Noriyoshi
Division of Applied Oral Science, Nihon University Graduate School of Dentistry, Tokyo, Japan.
Department of Periodontology, Nihon University School of Dentistry, Tokyo, Japan.
Biochem Biophys Res Commun. 2017 Dec 16;494(3-4):663-667. doi: 10.1016/j.bbrc.2017.10.107. Epub 2017 Oct 20.
Mechanical stimuli such as fluid shear and cyclic tension force induced extracellular adenosine triphosphate (ATP) release in osteoblasts. In particular, cyclic tension force-induced ATP enhances bone formation through P2X7 activation. Proline-rich tyrosine kinase 2 (PYK2) mediate osteoblasts differentiation is induced by mechanical stimuli. Furthermore, activation of PYK2 also was a response to integrin by mechanical stimuli. Extracellular matrix protein (ECMP)s, which are important factors for bone formation are expressed by osteoblasts. However, the effect of the interaction of 2'(3)-Ο-(4-Benzoylbenzoyl) adenosine-5'-triphosphate (BzATP), which is the agonist of the mechanosensitive receptor P2X7, with PYK2 on ECMP production is poorly understood. Thus, our purpose was to investigate the effects of PYK2 on BzATP-induced ECMP production in osteoblasts. BzATP increased phospho-PYK2 protein expression on days 3 and 7 of culture. Furthermore, the PYK2 inhibitor PF431394 inhibited the stimulatory effect of BzATP on the expression of type I collagen, bone sialoprotein and osteocalcin expression. PF431396 did not inhibit the stimulatory effect of BzATP on osteopontin (OPN) mRNA expression. These results suggest that mechanical stimuli activate P2X7 might induce ECMPs expression through PYK2 except in the case of OPN expression. Altogether, mechanical stimuli-induced ECMPs production might be implicated by extracellular ATP secretion or integrin via PYK2 activation.
流体剪切力和周期性张力等机械刺激可诱导成骨细胞释放细胞外三磷酸腺苷（ATP）。特别是，周期性张力诱导的ATP通过P2X7激活增强骨形成。富含脯氨酸的酪氨酸激酶2（PYK2）介导的成骨细胞分化由机械刺激诱导。此外，PYK2的激活也是机械刺激对整合素的一种反应。细胞外基质蛋白（ECMP）是骨形成的重要因素，由成骨细胞表达。然而，机械敏感受体P2X7的激动剂2'（3）-Ο-（4-苯甲酰苯甲酰基）腺苷-5'-三磷酸（BzATP）与PYK2相互作用对ECMP产生的影响尚不清楚。因此，我们的目的是研究PYK2对BzATP诱导的成骨细胞ECMP产生的影响。在培养的第3天和第7天，BzATP增加了磷酸化PYK2蛋白的表达。此外，PYK2抑制剂PF431394抑制了BzATP对I型胶原蛋白、骨唾液蛋白和骨钙素表达的刺激作用。PF431396没有抑制BzATP对骨桥蛋白（OPN）mRNA表达的刺激作用。这些结果表明，机械刺激激活P2X7可能通过PYK2诱导ECMPs表达，但OPN表达除外。总之，机械刺激诱导的ECMPs产生可能与细胞外ATP分泌或通过PYK2激活的整合素有关。
