Phosphophoryn regulates the gene expression and differentiation of NIH3T3, MC3T3-E1, and human mesenchymal stem cells via the integrin/MAPK signaling pathway
Phosphophoryn regulates the gene expression and differentiation of NIH3T3, MC3T3-E1, and human mesenchymal stem cells via the integrin/MAPK signaling pathway
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DOI：
10.1074/jbc.m404934200
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发表时间：
2004-12-17
影响因子：
4.8
通讯作者：
Sfeir, C
中科院分区：
文献类型：
--
作者：
Jadlowiec, J;Koch, H;Sfeir, C
细胞外基质蛋白（ECM）既是细胞的结构支持，也是指导细胞活动的动态生化网络。ECM蛋白，如SIBLING家族（小整合素结合配体糖蛋白）的那些蛋白，可能具有固有的生长因子活性。在这项研究中，我们证明了牙本质基质蛋白3（磷酸蛋白（PP）），非胶原牙本质ECM蛋白和SIBLING蛋白家族成员的外显子5，上调成骨细胞标记基因在原代人成体间充质干细胞（hMSCs），小鼠成骨细胞系（MC 3 T3-E1），和小鼠成纤维细胞系（NIH 3 T3）。使用定量实时PCR技术定量骨标志物的基因表达水平，如Runx 2、Osx（Osterix）、骨/肝/肾Alp（碱性磷酸酶）、Ocn（骨钙蛋白）和Bsp（骨唾液蛋白）对重组PP和稳定转染PP的反应。PP上调Runx 2、Osx和Ocn基因表达。PP增加hMSC和MC 3 T3-E1中OCN蛋白的产生。PP可增加hMSC中ALP活性和钙沉积。此外，α（v）β（3）整合素阻断抗体显著抑制重组PP诱导的hMSC中Runx 2的表达，表明PP的信号传导通过整合素途径介导。PP也被证明激活p38，ERK 1/2和JNK，MAPK途径的三个组成部分。这些数据证明了PP在细胞分化中的一种新的信号传导功能，超出了PP在生物矿化中的假设作用。
Extracellular matrix proteins (ECMs) serve as both a structural support for cells and a dynamic biochemical network that directs cellular activities. ECM proteins such as those of the SIBLING family ( small integrin-binding ligand glycoprotein) could possess inherent growth factor activity. In this study, we demonstrate that exon 5 of dentin matrix protein 3 ( phosphophoryn ( PP)), a non-collagenous dentin ECM protein and SIBLING protein family member, up-regulates osteoblast marker genes in primary human adult mesenchymal stem cells (hMSCs), a mouse osteoblastic cell line (MC3T3-E1), and a mouse fibroblastic cell line (NIH3T3). Quantitative real-time PCR technology was used to quantify gene expression levels of bone markers such as Runx2, Osx (Osterix), bone/liver/kidney Alp ( alkaline phosphatase), Ocn ( osteocalcin), and Bsp ( bone sialoprotein) in response to recombinant PP and stably transfected PP. PP up-regulated Runx2, Osx, and Ocn gene expression. PP increased OCN protein production in hMSCs and MC3T3-E1. ALP activity and calcium deposition was increased by PP in hMSC. Furthermore, an alpha(v)beta(3) integrin-blocking antibody significantly inhibited recombinant PP-induced expression of Runx2 in hMSCs, suggesting that signaling by PP is mediated through the integrin pathway. PP was also shown to activate p38, ERK1/2, and JNK, three components of the MAPK pathway. These data demonstrate a novel signaling function for PP in cell differentiation beyond the hypothesized role of PP in biomineralization.