RGD-CAP (βig-h3) is expressed in precartilage condensation and in prehypertrophic chondrocytes during cartilage development
RGD-CAP (βig-h3) is expressed in precartilage condensation and in prehypertrophic chondrocytes during cartilage development
复制标题
DOI：
10.1016/s0304-4165(02)00286-6
复制
发表时间：
2002-08-15
影响因子：
3
通讯作者：
Tanne, K
中科院分区：
文献类型：
--
作者：
Ohno, S;Doi, T;Tanne, K
RGD-CAP(Betaig-h3)是从软骨中分离出来的一种胶原相关蛋白，被证明具有与胶原结合的能力，并通过整合素α(1)β(1)增强软骨细胞的黏附。然而，这种蛋白在软骨发育中的作用尚不清楚。在本研究中，我们研究了RGD-CAP(β-h3)在鸡胚胎和培养的间充质干细胞(MSCs)向软骨细胞分化过程中的表达。观察重组RGD-CAP对MSCs黏附、DNA合成及矿化的影响。取汉堡包-汉密尔顿(Hamburger-Hamilton，HH)19-37期鸡胚组织切片，用RGD-CAP抗体进行免疫组化染色。RGD-CAP在HH期19的鸡胚中表达最弱，而在HH期26的发育中的脊椎和肢芽的软骨前聚集体中有大量表达。RGD-CAP在HH期鸡胚椎骨中的表达显著降低。逆转录聚合酶链式反应(RT-PCR)分析显示，RGD-CAP在培养的MSCs中高表达，10(-8)M地塞米松处理4d后其表达下降，而当MSCs向肥大的软骨细胞增殖时，经3 ng/mlTGF-β共处理8~12d，其黏附力和DNA合成均明显高于对照组。RGD-CAP分布于HH期鸡胚椎骨软骨的前肥大区。重组RGD-CAP抑制肥大软骨细胞矿化。这些结果表明，RGD-CAP(Betaig-h3)通过促进前软骨细胞的黏附和生长在早期软骨发育中发挥重要作用，并在软骨分化的终末阶段作为矿化的负调控因子发挥作用。(C)2002 Elsevier Science B.V.保留所有权利。
RGD-CAP (betaig-h3), isolated from cartilage as a collagen-associated protein, was demonstrated to have a binding ability to collagen and to enhance the adhesion of chondrocytes via integrin alpha(1)beta(1). However, the role of this protein in cartilage development remains unclear. In this study, we investigated the expression of RGD-CAP (betaig-h3) in chick embryos and cultured mesenchymal stem cells (MSCs) during the differentiation to chondrocytes. The effects of recombinant RGD-CAP on adhesion and DNA synthesis of MSCs and mineralization were also examined. Tissue sections from chick embryos at Hamburger-Hamilton (HH) stages 19-37 were immumostained with anti-chick RGD-CAP antibodies. The expression of RGD-CAP was slightest in chick embryos at HH stage 19, whereas a considerable expression of RGD-CAP was observed in the developing vertebrae and precartilage aggregate in the limb bud of chick embryos at HH stage 26. The expression of RGD-CAP was significantly reduced in vertebrae of chick embryo at HH stage 32. Reverse transcriptional polymerase chain reaction (RTPCR) analysis showed that RGD-CAP was highly expressed in cultured MSCs and decreased by 4-day treatment with 10(-8) M dexamethasone when MSCs proliferated to adipocyte-like cells, whereas it was recovered by co-treatment with 3 ng/ml TGF-beta for 8-12 days when MSCs proliferated to hypertrophic chondrocyte-like cells, The adhesion and DNA synthesis of MSCs cultured on RGD-CAP-coated dishes increased significantly compared with the controls. RGD-CAP was distributed in the prehypertrophic zone in matured cartilage of the vertebrae of chick embryos at HH stage 37. Recombinant RGD-CAP inhibited the mineralization of hypertrophic chondrocytes. These results suggest that RGD-CAP (betaig-h3) exerts an essential role in the early cartilage development by enhancing the adhesion and growth of the pre-chondrogenic cells, and functions as a negative regulator for mineralization at the terminal stage of the chondrogenic differentiation. (C) 2002 Elsevier Science B.V. All rights reserved.