Transgenic Expression of Osteoactivin/gpnmb Enhances Bone Formation In Vivo and Osteoprogenitor Differentiation Ex Vivo.
Transgenic Expression of Osteoactivin/gpnmb Enhances Bone Formation In Vivo and Osteoprogenitor Differentiation Ex Vivo.
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骨活性蛋白/GPNMB的转基因表达增强了体内和骨基因生成剂分化的骨形成。
DOI：
10.1002/jcp.25020
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发表时间：
2016-01
影响因子：
5.6
通讯作者：
Safadi FF
中科院分区：
文献类型：
--
作者：
Frara N;Abdelmagid SM;Sondag GR;Moussa FM;Yingling VR;Owen TA;Popoff SN;Barbe MF;Safadi FF
在骨质疏松大鼠模型中初步发现了骨激活素(OA)/糖蛋白非黑色素瘤克隆B(GPNMB)，在突变的骨骼中，OA的表达是正常骨的3倍。在骨折后活跃的骨再生过程中，OAmRNA和蛋白的表达增加，原代大鼠成骨细胞在体外分化过程中表现出OAmRNA和蛋白的表达增加。为了进一步研究OA/GPNMB作为骨诱导剂的作用，我们研究了在CMV启动子(OA-TG)下过表达OA/GPNMB的转基因小鼠的骨骼表型。Western印迹分析显示，与野生型(WT)相比，OA-TG成骨细胞中的OA/GPNMB增加。在OA-TG小鼠与WT胎鼠的股骨中，Micro-CT分析显示骨小梁体积和厚度以及皮质骨厚度增加；组织形态计量学显示OA-TG小鼠的成骨细胞数量、骨形成和矿物质沉积率增加；生物力学测试显示更高的峰值力矩和硬度。鉴于OA/GPNMB在OA-TG小鼠破骨细胞中也有过表达，我们通过ELISA法和组织形态计量学评价了骨吸收，并观察到与WT小鼠相比，OA-TG小鼠血清CTX-1和RANK-L水平降低，破骨细胞数量减少，表明OA-TG小鼠的骨重建减少。与WT相比，OATG成骨细胞体外增殖率高，碱性磷酸酶染色和活性高，后者提示OATG成骨细胞的分化增强。RT-β定量分析显示，与西药组相比，成骨细胞转化生长因子-β1及其受体I和II的表达增加。综上所述，这些数据表明，在体内，过表达的OA对骨量有诱导作用，并在体外刺激骨祖细胞的分化。
Initial identification of osteoactivin (OA)/glycoprotein non-melanoma clone B (gpnmb) was demonstrated in an osteopetrotic rat model, where OA expression was increased 3-fold in mutant bones, compared to normal. OA mRNA and protein expression increase during active bone regeneration post-fracture, and primary rat osteoblasts show increased OA expression during differentiation in vitro. To further examine OA/gpnmb as an osteoinductive agent, we characterized the skeletal phenotype of transgenic mouse overexpressing OA/gpnmb under the CMV-promoter (OA-Tg). Western blot analysis showed increased OA/gpnmb in OA-Tg osteoblasts, compared to wild-type (WT). In OA-Tg mouse femurs versus WT littermates, micro-CT analysis showed increased trabecular bone volume and thickness, and cortical bone thickness; histomorphometry showed increased osteoblast numbers, bone formation and mineral apposition rates in OA-Tg mice; and biomechanical testing showed higher peak moment and stiffness. Given that OA/gpnmb is also over-expressed in osteoclasts in OA-Tg mice, we evaluated bone resorption by ELISA and histomorphometry, and observed decreased serum CTX-1 and RANK-L, and decreased osteoclast numbers in OA-Tg, compared to WT mice, indicating decreased bone remodeling in OA-Tg mice. The proliferation rate of OA-Tg osteoblasts in vitro was higher, compared to WT, as was alkaline phosphatase staining and activity, the latter indicating enhanced differentiation of OA-Tg osteoprogenitors. Quantitative RT-PCR analysis showed increased TGF-β1 and TGF-β receptors I and II expression in OA-Tg osteoblasts, compared to WT. Together, these data suggest that OA overexpression has an osteoinductive effect on bone mass in vivo and stimulates osteoprogenitor differentiation ex vivo.
影响因子：
4.1
作者：
Joshi, R. N.;Safadi, F. F.;Barbe, M. F.;Del Carpio-Cano, Fe;Popoff, S. N.;Yingling, V. R.
通讯作者：
Yingling, V. R.