Tarr Joseph T, Visser Timothy G, Moon Joanne E, Hendesi Honey, Barbe Mary F, Bradley James P, Popoff Steven N
Department of Anatomy and Cell Biology, Lewis Katz School of Medicine at Temple University, 3500 N. Broad St. Suite 440, Philadelphia, PA, 19140, USA.
Department of General Surgery, Division of Plastic and Reconstructive Surgery, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, 19140, USA.
J Cell Commun Signal. 2017 Mar;11(1):25-37. doi: 10.1007/s12079-016-0360-8. Epub 2016 Oct 20.
Mammalian palatogenesis is a complex process involving a temporally and spatially regulated myriad of factors. Together these factors control the 3 vital processes of proliferation, elevation and fusion of the developing palate. In this study, we show for the first time the unequivocally vital role of CCN2 in development of the mammalian palate. We utilized CCN2 knockout (KO) mice and cranial neural crest derived mesenchymal cells from these CCN2 KO mice to investigate the 3 processes crucial to normal palatogenesis. Similar to previously published reports, the absence of CCN2 inhibits proliferation of cells in the palate specifically at the G1/S transition. Absence of CCN2 also inhibited palatal shelf elevation from the vertical to horizontal position. CCN2 KO mesenchymal cells demonstrated deficiencies in adhesion and spreading owing to an inability to activate Rac1 and RhoA. On the contrary, CCN2 KO mesenchymal cells exhibited increased rates of migration compared to WT cells. The addition of exogenous CCN2 to KO mesenchymal cells restored their ability to spread normally on fibronectin. Finally, utilizing an organ culture model we show that the palatal shelves of the CCN2 KO mice demonstrate an inability to fuse when apposed. Together, these data signify that CCN2 plays an indispensible role in normal development of the mammalian palate and warrants additional studies to determine the precise mechanism(s) responsible for these effects.
哺乳动物的腭发育是一个复杂的过程,涉及众多在时间和空间上受到调控的因素。这些因素共同控制着发育中的腭的增殖、抬高和融合这三个重要过程。在本研究中,我们首次明确展示了CCN2在哺乳动物腭发育中至关重要的作用。我们利用CCN2基因敲除(KO)小鼠以及来自这些CCN2 KO小鼠的颅神经嵴衍生间充质细胞,来研究对正常腭发育至关重要的三个过程。与先前发表的报告相似,CCN2的缺失特异性地在G1/S期转变时抑制腭部细胞的增殖。CCN2的缺失还抑制了腭板从垂直位置向水平位置的抬高。由于无法激活Rac1和RhoA,CCN2 KO间充质细胞在黏附和铺展方面表现出缺陷。相反,与野生型(WT)细胞相比,CCN2 KO间充质细胞的迁移速率增加。向KO间充质细胞中添加外源性CCN2可恢复它们在纤连蛋白上正常铺展的能力。最后,利用器官培养模型,我们发现CCN2 KO小鼠的腭板在对合时无法融合。总之,这些数据表明CCN2在哺乳动物腭的正常发育中起着不可或缺的作用,值得进一步研究以确定造成这些影响的精确机制。