Jumabay Medet, Zhumabai Jiayinaguli, Mansurov Nurlan, Niklason Katharine C, Guihard Pierre J, Cubberly Mark R, Fogelman Alan M, Iruela-Arispe Luisa, Yao Yucheng, Saparov Arman, Boström Kristina I
Division of Cardiology, David Geffen School of Medicine at UCLA, Los Angeles, California.
Xinjiang Key Laboratory of Biological Resources and Genetic Engineering, College of Life Science and Technology, Xinjiang University, Urumqi, China.
J Cell Physiol. 2018 Mar;233(3):1812-1822. doi: 10.1002/jcp.25983. Epub 2017 Jun 6.
Bone morphogenetic protein (BMP) 10, a cardiac-restricted BMP family member, is essential in cardiomyogenesis, especially during trabeculation. Crossveinless-2 (CV2, also known as BMP endothelial cell precursor derived regulator [BMPER]) is a BMP-binding protein that modulates the activity of several BMPs. The objective of this study was to examine the combined effects of BMP10 and CV2 on cardiomyocyte differentiation using mouse dedifferentiated fat (mDFAT) cells, which spontaneously differentiate into cardiomyocyte-like cells, as a model. Our results revealed that CV2 binds directly to BMP10, as determined by co-immunoprecipitation, and inhibits BMP10 from initiating SMAD signaling, as determined by luciferase reporter gene assays. BMP10 treatment induced mDFAT cell proliferation, whereas CV2 modulated the BMP10-induced proliferation. Differentiation of cardiomyocyte-like cells proceeded in a reproducible fashion in mDFAT cells, starting with small round Nkx2.5-positive progenitor cells that progressively formed myotubes of increasing length that assembled into beating colonies and stained strongly for Troponin I and sarcomeric alpha-actinin. BMP10 enhanced proliferation of the small progenitor cells, thereby securing sufficient numbers to support formation of myotubes. CV2, on the other hand, enhanced formation and maturation of large myotubes and myotube-colonies and was expressed by endothelial-like cells in the mDFAT cultures. Thus BMP10 and CV2 have important roles in coordinating cardiomyogenesis in progenitor cells.
骨形态发生蛋白（BMP）10是一种心脏特异性的BMP家族成员，在心肌发生过程中，尤其是在小梁形成过程中至关重要。无交叉静脉-2（CV2，也称为BMP内皮细胞前体衍生调节因子[BMPER]）是一种BMP结合蛋白，可调节多种BMP的活性。本研究的目的是使用小鼠去分化脂肪（mDFAT）细胞作为模型，研究BMP10和CV2对心肌细胞分化的联合作用，mDFAT细胞可自发分化为心肌样细胞。我们的结果显示，通过免疫共沉淀确定，CV2直接与BMP10结合；通过荧光素酶报告基因检测确定，CV2可抑制BMP10启动SMAD信号。BMP10处理可诱导mDFAT细胞增殖，而CV2可调节BMP10诱导的增殖。心肌样细胞的分化在mDFAT细胞中以可重复的方式进行，从小的圆形Nkx2.5阳性祖细胞开始，这些祖细胞逐渐形成长度增加的肌管，这些肌管组装成跳动的集落，并对肌钙蛋白I和肌节α-肌动蛋白进行强烈染色。BMP10可增强小祖细胞的增殖，从而确保有足够数量的细胞来支持肌管的形成。另一方面，CV2可增强大肌管和肌管集落的形成和成熟，并且在mDFAT培养物中的内皮样细胞中表达。因此，BMP10和CV2在协调祖细胞的心肌发生中具有重要作用。
