Chen Jiaxuan, Doroudi Maryam, Cheung Jeffery, Grozier Ashley L, Schwartz Zvi, Boyan Barbara D
Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA, USA; Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA.
Cell Signal. 2013 Dec;25(12):2362-73. doi: 10.1016/j.cellsig.2013.07.020. Epub 2013 Jul 27.
1α,25-Dihydroxyvitamin D3 (1α,25(OH)2D3) regulates osteoblasts through genomic and rapid membrane-mediated responses. Here we examined the interaction of protein disulfide isomerase family A, member 3 (Pdia3) and the traditional vitamin D receptor (VDR) in plasma membrane-associated responses to 1α,25(OH)2D3. We found that Pdia3 co-localized with VDR and the caveolae scaffolding protein, caveolin-1 on the surface of MC3T3-E1 osteoblasts. Immunoprecipitation showed that both Pdia3 and VDR interacted with caveolin-1. Pdia3 further interacted with phospholipase A2 activating protein (PLAA), whereas VDR interacted with c-Src. 1α,25(OH)2D3 changed the interactions and transport of the two receptors and rapidly activated phospholipase A2 (PLA2) and c-Src. Silencing either receptor or caveolin-1 inhibited both PLA2 and c-Src, indicating that the two receptors function interdependently. These two receptor dependent rapid responses to 1α,25(OH)2D3 regulated gene expression, proliferation and apoptosis of MC3T3-E1 cells. These data demonstrate the importance of both receptors and caveolin-1 in mediating membrane responses to 1α,25(OH)2D3 and subsequently regulating osteoblast biology.
1α,25-二羟基维生素D3（1α,25(OH)2D3）通过基因组和快速的膜介导反应调节成骨细胞。在此，我们研究了蛋白二硫键异构酶A家族成员3（Pdia3）与传统维生素D受体（VDR）在对1α,25(OH)2D3的质膜相关反应中的相互作用。我们发现Pdia3与VDR以及小窝支架蛋白小窝蛋白-1在MC3T3-E1成骨细胞表面共定位。免疫沉淀显示Pdia3和VDR都与小窝蛋白-1相互作用。Pdia3进一步与磷脂酶A2激活蛋白（PLAA）相互作用，而VDR与c-Src相互作用。1α,25(OH)2D3改变了这两种受体的相互作用和转运，并迅速激活磷脂酶A2（PLA2）和c-Src。沉默任一受体或小窝蛋白-1均抑制PLA2和c-Src，表明这两种受体相互依赖发挥作用。这两种受体对1α,25(OH)2D3的依赖性快速反应调节了MC3T3-E1细胞的基因表达、增殖和凋亡。这些数据证明了这两种受体和小窝蛋白-1在介导对1α,25(OH)2D3的膜反应以及随后调节成骨细胞生物学方面的重要性。
