Zhang He, Chang Hao, Wang Li-mei, Ren Ke-feng, Martins M Cristina L, Barbosa Mário A, Ji Jian
MOE Key Laboratory of Macromolecule Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University , Hangzhou 310027, China.
State Key Laboratory of Molecular Engineering of Polymers, Fudan University , Shanghai, China.
Biomacromolecules. 2015 Nov 9;16(11):3584-93. doi: 10.1021/acs.biomac.5b01057. Epub 2015 Oct 23.
Endothelial-to-mesenchymal transition (EndMT), during which endothelial cells (ECs) transdifferentiate into mesenchymal phenotype, plays a key role in the development of vascular implant complications such as endothelium dysfunction and in-stent restenosis. Substrate stiffness has been confirmed as a key factor to influence EC behaviors; however, so far, the relationship between substrate stiffness and EndMT has been rarely studied. Here, ECs were cultured on the (poly(L-lysine)/hyaluronate acid) (PLL/HA) multilayer films with controlled stiffness for 2 weeks, and their EndMT behaviors were studied. We demonstrated that ECs lost their markers (vWf and CD31) in a stiffness-dependent manner even without supplement of growth factors, and the softer film favored the maintaining of EC phenotype. Further, induced by transforming growth factor β1 (TGF-β1), ECs underwent EndMT, as characterized by losing their typical cobblestone morphology and markers and gaining smooth muscle cell markers (α-smooth muscle actin and calponin). Interestingly, stronger EndMT was observed when ECs were cultured on the stiffer film. Collectively, our findings suggest that substrate stiffness has significant effects on EndMT, and a softer substrate is beneficial to ECs by keeping their phenotype and inhibiting EndMT, which presents a new strategy for surface design of vascular implant materials.
内皮-间充质转化（EndMT）过程中，内皮细胞（ECs）转分化为间充质表型，在血管植入物并发症（如内皮功能障碍和支架内再狭窄）的发生发展中起关键作用。底物硬度已被确认为影响内皮细胞行为的关键因素；然而，迄今为止，底物硬度与EndMT之间的关系鲜有研究。在此，将内皮细胞接种于具有可控硬度的（聚L-赖氨酸/透明质酸）（PLL/HA）多层膜上培养2周，并对其EndMT行为进行研究。我们发现，即使不添加生长因子，内皮细胞也会以硬度依赖的方式丢失其标志物（血管性血友病因子和CD31），且较软的膜更有利于维持内皮细胞表型。此外，在转化生长因子β1（TGF-β1）诱导下，内皮细胞发生EndMT，表现为失去典型的鹅卵石样形态和标志物，并获得平滑肌细胞标志物（α-平滑肌肌动蛋白和钙调蛋白）。有趣的是，当内皮细胞在较硬的膜上培养时，观察到更强的EndMT。总体而言，我们的研究结果表明，底物硬度对EndMT有显著影响，较软的底物通过保持内皮细胞表型和抑制EndMT对其有益，这为血管植入材料的表面设计提供了一种新策略。
