Zeng Qiangcheng, Guo Yong, Liu Yongming, Li Ruixin, Zhang Xinchang, Liu Lu, Wang Yang, Zhang Xizheng, Zou Xianqiong
Shandong Provincial Key Laboratory of Functional Macromolecular Biophysics, Institute of Biophysics, Dezhou University, Dezhou, 253023, Shandong, China.
College of Biotechnology, Guilin Medical University, Guilin, 541004, Guangxi, China.
Biol Res. 2015 May 14;48(1):25. doi: 10.1186/s40659-015-0014-y.
Mechanical strain plays a great role in growth and differentiation of osteoblast. A previous study indicated that integrin-β (β1, β5) mediated osteoblast proliferation promoted by mechanical tensile strain. However, the involvement of integrin-β in osteoblastic differentiation and extracellular matrix (ECM) formation induced by mechanical tensile strain, remains unclear.
After transfection with integrin-β1 siRNA or integrin-β5 siRNA, mouse MC3T3-E1 preosteoblasts were cultured in cell culture dishes and stimulated with mechanical tensile strain of 2500 microstrain (με) at 0.5 Hz applied once a day for 1 h over 3 or 5 consecutive days. The cyclic tensile strain promoted osteoblastic differentiation of MC3T3-E1 cells. Transfection with integrin-β1 siRNA attenuated the osteoblastic diffenentiation induced by the tensile strain. By contrast, transfection with integrin-β5 siRNA had little effect on the osteoblastic differentiation induced by the strain. At the same time, the result of ECM formation promoted by the strain, was similar to the osteoblastic differentiation.
Integrin-β1 mediates osteoblast differentiation and osteoblastic ECM formation promoted by cyclic tensile strain, and integrin-β5 is not involved in the osteoblasts response to the tensile strain.
机械应变在成骨细胞的生长和分化中起重要作用。先前的一项研究表明，整合素-β（β1、β5）介导机械拉伸应变促进的成骨细胞增殖。然而，整合素-β在机械拉伸应变诱导的成骨细胞分化和细胞外基质（ECM）形成中的作用仍不清楚。
用整合素-β1小干扰RNA（siRNA）或整合素-β5 siRNA转染后，将小鼠MC3T3-E1前成骨细胞培养于细胞培养皿中，以0.5赫兹的频率施加2500微应变（με）的机械拉伸应变，每天一次，每次1小时，连续3天或5天。循环拉伸应变促进了MC3T3-E1细胞的成骨细胞分化。用整合素-β1 siRNA转染减弱了拉伸应变诱导的成骨细胞分化。相比之下，用整合素-β5 siRNA转染对该应变诱导的成骨细胞分化影响不大。同时，该应变促进的ECM形成结果与成骨细胞分化相似。
整合素-β1介导循环拉伸应变促进的成骨细胞分化和成骨细胞ECM形成，而整合素-β5不参与成骨细胞对拉伸应变的反应。
