Bone morphogenetic protein-2 can mediate myocardial regulation of atrioventricular cushion mesenchymal cell formation in mice
Bone morphogenetic protein-2 can mediate myocardial regulation of atrioventricular cushion mesenchymal cell formation in mice
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DOI：
10.1016/j.ydbio.2004.01.045
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发表时间：
2004-05-13
影响因子：
2.7
通讯作者：
Markwald, RR
中科院分区：
文献类型：
--
作者：
Sugi, Y;Yamamura, H;Markwald, RR
内皮细胞向侵袭性间充质的转化是心脏垫组织形成的重要前提。已知骨形态发生蛋白（BMP）-2的信息在心肌细胞中以与垫形成的节段模式一致的方式表达[开发109（1990）833]。在目前的工作中，我们本地化的BMP-2蛋白在房室（AV）心肌在胚胎天（艾德）8.5（12体节期）的小鼠在发病前的AV间充质细胞形成在艾德9.5。BMP-2蛋白表达缺席整个阶段的心室肌。在艾德10.5的AV垫细胞化后，AV心肌中的心肌BMP-2蛋白表达减少，而垫间充质细胞开始表达BMP蛋白。在发育后期，艾德13.5 - 16，在valuvulogenesis期间，垫间充质中BMP-2的表达持续存在。BMP-2在成年小鼠的瓣膜组织中持续强烈表达。基于这种表达模式，我们进行了一系列实验来验证BMP-2介导小鼠心脏垫组织形成的心肌调节的假设。当BMP-2蛋白加入到培养的16 - 18体节期（艾德9.25）AV内皮细胞中时，在AV心肌不存在的情况下形成垫间充质细胞，其侵入胶原凝胶并表达间充质标志物平滑肌（SM）α-肌动蛋白;而内皮标志物PECAM-1从侵入的细胞中丢失。与此相反，当noggin，一种BMP的特异性拮抗剂，与BMP-2一起施加到培养基中，AV内皮细胞保持为上皮单层，SM α-肌动蛋白表达很少，PECAM-1的表达保留在内皮细胞中。当noggin加入到与相关心肌共培养的AV内皮细胞中时，它阻断了内皮向间充质的转化。与在与心肌共培养的内皮中观察到的一样，在没有心肌的情况下，用BMP-2处理的AV内皮表达升高的TGF β-2水平。BMP-2支持的内皮细胞中TGF β-2表达的升高被头蛋白处理所消除。这些数据表明，BMP信号是必需的，BMP-2是足够的心肌节段性调节房室内膜垫间充质细胞形成在小鼠。(C)2004年爱思唯尔公司保留所有权利。
Transformation of endocardial endothelial cells into invasive mesenchyme is a critical antecedent of cardiac cushion tissue fort-nation. The message for bone morphogenctic protein (BMP)-2 is known to be expressed in myocardial cells in a manner consistent with the segmental pattern of cushion formation [Development 109(1990) 833]. In the present work, we localized BMP-2 protein in atrioventricular (AV) myocardium in mice at embryonic day (ED) 8.5 (12 somite stage) before the onset of AV mesenchymal cell formation at ED 9.5. BMP-2 protein expression was absent from ventricular myocardium throughout the stages examined. After cellularization of the AV cushion at ED 10.5, myocardial BMP-2 protein expression was diminished in AV myocardium, whereas cushion mesenchymal cells started expressing BMP protein. Expression of BMP-2 in cushion mesenchyme persisted during later stages of development, ED 13.5-16, during valuvulogenesis. Intense expression of BMP-2 persisted in the valve tissue in adult mice. Based on the expression pattern, we performed a series of experiments to test the hypothesis that BMP-2 mediates myocardial regulation of cardiac cushion tissue formation in mice. When BMP-2 protein was added to the 16-18 somite stage (ED 9.25) AV endocardial endothelium in culture, cushion mesenchymal cells were formed in the absence of AV myocardium, which invaded into collagen gels and expressed the mesenchymal marker, smooth muscle (SM) alpha-actin; whereas the endothelial marker, PECAM-1, was lost from the invaded cells. In contrast, when noggin, a specific antagonist to BMPs, was applied together with BMP-2 to the culture medium, AV endothelial cells remained as an epithelial monolayer with little expression of SM a-actin, and expression of PECAM-1 was retained in the endocardial cells. When noggin was added to AV endothelial cells cocultured with associated myocardium, it blocked endothelial transformation to mesenchyme. AV endothelium treated with BMP-2 expressed elevated levels of TGFbeta-2 in the absence of myocardium, as observed in the endothelium cocultured with myocardium. BMP-2-supported elevation of TGFbeta-2 expression in endocardial cells was abolished by noggin treatment. These data indicated that BMP signaling is required in and BMP-2 is sufficient for myocardial segmental regulation of AV endocardial cushion mesenchymal cell formation in mice. (C) 2004 Elsevier Inc. All rights rserved.