Tsukune Naoya, Naito Masako, Kubota Tatsuya, Ozawa Yasumasa, Nagao Mayu, Ohashi Akiko, Sato Shuichi, Takahashi Tomihisa
Division of Applied Oral Science, Nihon University Graduate School of Dentistry, Tokyo, Japan.
Department of Anatomy, Nihon University School of Dentistry, Tokyo, Japan; Division of Functional Morphology, Dental Research Center, Nihon University School of Dentistry, Tokyo, Japan.
Biochem Biophys Res Commun. 2017 Jul 8;488(4):664-670. doi: 10.1016/j.bbrc.2017.02.110. Epub 2017 Feb 22.
Lamin A/C is a component of the nuclear lamina, which is involved in cellular proliferation and differentiation. However, the mechanism by which lamin A regulates osteoblast differentiation is not well understood. In this study, we investigated lamin A/C expression during osteoblast differentiation in a preosteoblastic cell line, MC3T3-E1. Real-time PCR analysis showed that lamin A/C mRNA expression was upregulated during BMP-2 induced osteoblast differentiation. Treatment with the estrogen receptor antagonist, fulvestrant, inhibited osteoblast differentiation and the upregulation of lamin A/C mRNA and protein expressions in the presence of BMP-2. These results clearly demonstrated that lamin A/C expression correlates with osteoblast differentiation. To determine the roles of lamin A expression in osteoblast differentiation, MC3T3-E1 cells were transfected with a vector overexpressing lamin A. Results showed that lamin A overexpression promoted osteoblast differentiation and calcification by inducing the expression of alkaline phosphatase, type 1 collagen, BSP, osteocalcin, and DMP-1 in the presence of BMP-2. Furthermore, lamin A overexpression partially restored osteoblastic capacity in the presence of fulvestrant by increasing the expression of BSP, osteocalcin, and DMP-1. These results suggest that lamin A plays important roles in maintaining the osteoblast differentiation and function.
核纤层蛋白A/C是核纤层的一个组成部分，参与细胞增殖和分化。然而，核纤层蛋白A调节成骨细胞分化的机制尚未完全明确。在本研究中，我们调查了前成骨细胞系MC3T3-E1在成骨细胞分化过程中核纤层蛋白A/C的表达情况。实时PCR分析表明，在骨形态发生蛋白-2（BMP-2）诱导的成骨细胞分化过程中，核纤层蛋白A/C mRNA表达上调。用雌激素受体拮抗剂氟维司群处理，在有BMP-2存在的情况下，抑制了成骨细胞分化以及核纤层蛋白A/C mRNA和蛋白表达的上调。这些结果清楚地表明，核纤层蛋白A/C表达与成骨细胞分化相关。为了确定核纤层蛋白A表达在成骨细胞分化中的作用，用一个过表达核纤层蛋白A的载体转染MC3T3-E1细胞。结果显示，在有BMP-2存在的情况下，核纤层蛋白A过表达通过诱导碱性磷酸酶、I型胶原、骨涎蛋白、骨钙素和牙本质基质蛋白-1的表达促进了成骨细胞分化和钙化。此外，在有氟维司群存在的情况下，核纤层蛋白A过表达通过增加骨涎蛋白、骨钙素和牙本质基质蛋白-1的表达部分恢复了成骨细胞能力。这些结果表明，核纤层蛋白A在维持成骨细胞分化和功能中发挥重要作用。
