Autogenous regulation of a network of bone morphogenetic proteins (BMPs) mediates the osteogenic differentiation in murine marrow stromal cells
Autogenous regulation of a network of bone morphogenetic proteins (BMPs) mediates the osteogenic differentiation in murine marrow stromal cells
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DOI：
10.1016/j.bone.2007.01.001
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发表时间：
2007-05-01
期刊：
影响因子：
4.1
通讯作者：
Einhorn, Thomas A.
中科院分区：
文献类型：
--
作者：
Edgar, Cory M.;Chakravarthy, Vinay;Einhorn, Thomas A.
骨形态发生蛋白在骨折修复和出生前骨发育过程中的表达模式表明，这些过程是通过多个骨形态发生蛋白的协调作用来调节的。培养的海洋骨髓基质细胞(MSCs)提供了一种公认的骨髓间充质干细胞体外分化系统，在其中可以检测BMPs的作用。研究确定MSC的分化是否依赖于多个BMP的内源性表达，并表征它们的相互作用。取8~10周龄雄性C57/136小鼠胫骨和股骨骨髓，按标准方法制备MSCs。通过组织学检测、碱性磷酸酶活力测定和BMPs及成骨发育相关多个mRNAs的表达来评价成骨分化。在功能获得和功能丧失实验中评估了自体表达的BMPs在控制骨髓基质细胞体外成骨分化中的作用。功能获得实验在外源性添加BMP-2或-7存在的情况下进行，功能丧失实验通过BMP与noggin拮抗和BMP-2抗体阻断进行。成骨分化与BMPs-2、-3、-4、-5、-6和-8A的表达增加成正比。用noggin或BMP-2抗体阻断BMP拮抗剂分别抑制成骨分化50%~80%，并降低内源性BMPs-2、-3、-5和-8A的表达水平。相反，拮抗诱导BMP-4和BMP-6的表达。与BMP拮抗剂相比，rhBMP-2或-7的加入促进了成骨分化，并在内源性BMPs的表达中产生了互易的表达谱。BMP拮抗作用可通过竞争性添加rhBMP-2来挽救。这些研究表明，成骨分化是由多个BMP组成的复杂网络调控的，该网络在分化过程中表现出选择性的表达增加和减少。他们进一步证明BMP-2在这个网络中是一个中央调节因子。(C)2007 Elsevier Inc.保留所有权利。
The expression patterns of (bone morphogenetic proteins) BMPs during fracture repair and pre-natal bone development suggest that these processes are regulated through the coordinated actions of multiple BMPs. Marine bone marrow stromal cells (MSCs) in culture provide a well recognized ex vivo system of mesenchymal stem cell differentiation in which the effects of BMPs can be examined. Studies were performed to determine if MSC differentiation is dependent on the endogenous expression of multiple BMPs and to characterize their interactions. MSCs were harvested from the bone marrow of tibiae and femora of 8 to 10-week-old male C57/136 mice and prepared by standard methods. Osteogenic differentiation was assessed by histological assays, alkaline phosphatase enzyme activity and assays for the expression of multiple mRNAs for BMPs and osteogenic development. The role of autogenously expressed BMPs in controlling the osteogenic differentiation of marrow stromal cells in vitro was assessed in both gain-of-function and loss-of-function experiments. Gain of function experiments were carried out in the presence of exogenously added BMP-2 or -7 and loss-of-function experiments were carried out by BMP antagonism with noggin and BMP-2 antibody blockade. Osteogenic differentiation was concurrent with and proportional to increases in the expression of BMPs-2, -3, -4, -5, -6 and -8A. BMP antagonism with either noggin or BMP-2 antibody blockade inhibited osteogenic differentiation by 50% to 80%, respectively, and reduced the expression of endogenous levels of BMPs-2, -3, -5 and -8A. In contrast, antagonism induced the expression of BMP-4 and -6. The addition of rhBMP-2 or -7 enhanced osteogenic differentiation and produced a reciprocal expression profile in the endogenous BMPs expression as compared to BMP antagonism. BMP antagonism could be rescued through the competitive addition of rhBMP-2. These studies demonstrated that osteogenic differentiation was regulated by a complex network of multiple BMPs that showed selective increased and decreased expression during differentiation. They further demonstrated that BMP-2 was a central regulator in this network. (c) 2007 Elsevier Inc. All rights reserved.