Recombinant Vgr-1/BMP-6-expressing tumors induce fibrosis and endochondral bone formation in vivo.
Recombinant Vgr-1/BMP-6-expressing tumors induce fibrosis and endochondral bone formation in vivo.
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DOI：
10.1083/jcb.126.6.1595
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发表时间：
1994-09
影响因子：
7.8
通讯作者：
Derynck, R
中科院分区：
文献类型：
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作者：
Gitelman, S E;Kobrin, M S;Ye, J Q;Lopez, A R;Lee, A;Derynck, R
TGF-β超家族的成员似乎可以调节间充质分化，包括软骨和骨形成的过程。关于TGF-β相关因子vgr-1（也称为骨形态发生蛋白6（BMP-6））的功能尚不清楚，并且仅对最密切相关的因子BMP-5、成骨蛋白-1（OP-1）或BMP-7和OP-2进行了有限的研究。由于 vgr-1 mRNA 定位于肥大软骨中，因此该因子可能在软骨内骨形成中发挥重要作用。我们开发了 vgr-1 抗体，并记录了 vgr-1 蛋白在小鼠肥大软骨中表达。为了进一步表征该蛋白在骨分化中的作用，我们生成了过表达重组鼠 vgr-1 蛋白的 CHO 细胞。蛋白质印迹分析证明重组 vgr-1 蛋白被分泌到培养基中并经过蛋白水解加工产生成熟的 vgr-1 分子。为了评估重组vgr-1的体内生物活性，我们将表达vgr-1的CHO细胞直接导入无胸腺裸鼠的皮下组织中。 CHO-vgr-1 细胞产生局部肿瘤，并且 vgr-1 的持续分泌导致肿瘤与亲代 CHO 细胞相比具有显着不同的总体和组织学外观。对照 CHO 细胞的肿瘤出血、坏死且易碎，而 CHO-vgr-1 肿瘤致密、坚硬且纤维化。与对照 CHO 肿瘤相比，CHO-vgr-1 肿瘤细胞的巢被广泛的结缔组织包围，其中包含大面积的软骨和骨。进一步分析表明，转染的CHO肿瘤细胞分泌的vgr-1诱导周围宿主间充质细胞沿着软骨内骨途径发育。这些发现表明软骨内骨形成。
Members of the TGF-beta superfamily appear to modulate mesenchymal differentiation, including the processes of cartilage and bone formation. Nothing is yet known about the function of the TGF-beta- related factor vgr-1, also called bone morphogenetic protein-6 (BMP-6), and only limited studies have been conducted on the most closely related factors BMP-5, osteogenic protein-1 (OP-1) or BMP-7, and OP-2. Because vgr-1 mRNA has been localized in hypertrophic cartilage, this factor may play a vital role in endochondral bone formation. We developed antibodies to vgr-1, and documented that vgr-1 protein was expressed in hypertrophic cartilage of mice. To further characterize the role of this protein in bone differentiation, we generated CHO cells that overexpressed recombinant murine vgr-1 protein. Western blot analysis documented that recombinant vgr-1 protein was secreted into the media and was proteolytically processed to yield the mature vgr-1 molecule. To assess the biological activity of recombinant vgr-1 in vivo, we introduced the vgr-1-expressing CHO cells directly into the subcutaneous tissue of athymic nude mice. CHO-vgr-1 cells produced localized tumors, and the continuous secretion of vgr-1 resulted in tumors with a strikingly different gross and histological appearance as compared to the parental CHO cells. The tumors of control CHO cells were hemorrhagic, necrotic, and friable, whereas the CHO-vgr-1 tumors were dense, firm, and fibrotic. In contrast with control CHO tumors, the nests of CHO-vgr-1 tumor cells were surrounded by extensive connective tissue, which contained large regions of cartilage and bone. Further analysis indicated that secretion of vgr-1 from the transfected CHO tumor cells induced the surrounding host mesenchymal cells to develop along the endochondral bone pathway. These findings suggest that endochondral bone formation.