Arevalos C Alexander, Berg Jonathan M, Nguyen Jacqueline M V, Godfrey Elizabeth L, Iriondo Claudia, Grande-Allen K Jane
Department of Bioengineering, Rice University, 6100 Main St., MS 142, Houston, TX, 77005, USA.
Ann Biomed Eng. 2016 Sep;44(9):2707-23. doi: 10.1007/s10439-016-1567-9. Epub 2016 Feb 23.
Neovascularization is an understudied aspect of calcific aortic valve disease (CAVD). Within diseased valves, cells along the neovessels' periphery stain for pericyte markers, but it is unclear whether valvular interstitial cells (VICs) can demonstrate a pericyte-like phenotype. This investigation examined the perivascular potential of VICs to regulate valve endothelial cell (VEC) organization and explored the role of Angiopoeitin1-Tie2 signaling in this process. Porcine VECs and VICs were fluorescently tracked and co-cultured in Matrigel over 7 days. VICs regulated early VEC network organization in a ROCK-dependent manner, then guided later VEC network contraction through chemoattraction. Unlike vascular control cells, the valve cell cultures ultimately formed invasive spheroids with 3D angiogenic-like sprouts. VECs co-cultured with VICs displayed significantly more invasion than VECs alone; with VICs generally leading and wrapping around VEC invasive sprouts. Lastly, Angiopoietin1-Tie2 signaling was found to regulate valve cell organization during VEC/VIC spheroid formation and invasion. VICs demonstrated pericyte-like behaviors toward VECs throughout sustained co-culture. The change from a vasculogenic network to an invasive sprouting spheroid suggests that both cell types undergo phenotypic changes during long-term culture in the model angiogenic environment. Valve cells organizing into spheroids and undergoing 3D invasion of Matrigel demonstrated several typical angiogenic-like phenotypes dependent on basal levels of Angiopoeitin1-Tie2 signaling and ROCK activation. These results suggest that the ectopic sustained angiogenic environment during the early stages of valve disease promotes organized activity by both VECs and VICs, contributing to neovessel formation and the progression of CAVD.
新生血管形成是钙化性主动脉瓣疾病(CAVD)中一个研究较少的方面。在病变瓣膜中,沿新生血管周边的细胞可表达周细胞标志物,但尚不清楚瓣膜间质细胞(VICs)是否能表现出周细胞样表型。本研究检测了VICs调节瓣膜内皮细胞(VECs)组织的血管周围潜能,并探讨了血管生成素1 - 酪氨酸激酶2(Angiopoeitin1 - Tie2)信号在此过程中的作用。猪VECs和VICs通过荧光追踪,并在基质胶中共培养7天。VICs以一种依赖于Rho相关卷曲螺旋蛋白激酶(ROCK)的方式调节早期VEC网络组织,然后通过化学吸引引导后期VEC网络收缩。与血管对照细胞不同,瓣膜细胞培养物最终形成具有三维血管生成样芽的侵袭性球体。与VICs共培养的VECs比单独培养的VECs表现出显著更多的侵袭;通常是VICs引导并围绕VEC侵袭性芽。最后,发现血管生成素1 - Tie2信号在VEC/VIC球体形成和侵袭过程中调节瓣膜细胞组织。在持续共培养过程中,VICs对VECs表现出周细胞样行为。从血管生成网络到侵袭性芽生球体的转变表明,在模型血管生成环境中进行长期培养时,两种细胞类型都会发生表型变化。组织成球体并对基质胶进行三维侵袭的瓣膜细胞表现出几种典型的血管生成样表型,这些表型依赖于血管生成素1 - Tie2信号的基础水平和ROCK激活。这些结果表明,瓣膜疾病早期的异位持续血管生成环境促进了VECs和VICs的有组织活动,有助于新生血管形成和CAVD的进展。