Pressure-induced microstructural changes in porcine tricuspid valve leaflets
Pressure-induced microstructural changes in porcine tricuspid valve leaflets
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DOI：
10.1016/j.actbio.2017.11.040
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发表时间：
2018-02-01
影响因子：
9.7
通讯作者：
Amini, Rouzbeh
中科院分区：
文献类型：
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作者：
Pant, Anup D.;Thomas, Vineet S.;Amini, Rouzbeh
量化机械诱导的三尖瓣细胞外基质（ECM）结构组分的变化（例如胶原纤维的扩散和分布）非常重要，因为它决定了整体宏观组织反应以及随后在生理/病理生理状态下的功能/功能障碍。例如，功能性三尖瓣反流，一种常见的三尖瓣疾病，可能是由肺动脉高压引起的右心室压力升高引起的。在这样的患者中，瓣叶的几何形状和正常功能由于慢性压力超负荷而改变，这可能导致ECM中的重塑反应并改变其结构成分。为了理解这种关系，我们开发了一种实验装置，并使用小角光散射技术测量了猪三尖瓣中瓣叶微结构对压力增加的反应。获得各向异性指数，即纤维伸展和分布的量度，并对前、后和间隔的每个区域取平均值。使用四种平均方法的传单。未加压瓣膜的前、后和间隔瓣叶腹部区域的平均各向异性指数（平均标准误差）分别为12 +/-2%、21 +/-3%和12 +/-1%。对于加压瓣膜，前、后和间隔瓣叶腹部区域的各向异性指数平均值分别为56 +/-5%、39 +/-7%和32 +/-5%。总体而言，平均各向异性指数被认为是更高的所有小叶在加压的阀门相比，非加压的阀门，表明ECM纤维变得更加一致，在响应增加心室pressure. Statement of SignificanceMechanics起着至关重要的作用，在发展，再生和重塑组织。在目前的研究中，我们已经进行了实验，以检查如何增加心室压力导致重新排列的蛋白质纤维组成的细胞外基质（ECM）的三尖瓣叶。与许多其他组织一样，在心脏瓣膜中，细胞-基质相互作用和基因表达受到ECM/细胞水平的机械微环境变化的严重影响。我们相信，我们的研究将帮助我们更好地了解右心室压力异常增加（由于肺动脉高压）如何改变三尖瓣瓣叶的结构，以及随后在ECM/细胞水平上的机械微环境。(C)2017 Acta Materialia Inc.由爱思唯尔有限公司出版。保留所有权利。
Quantifying mechanically-induced changes in the tricuspid valve extracellular matrix (ECM) structural components, e.g. collagen fiber spread and distribution, is important as it determines the overall macro-scale tissue responses and subsequently its function/malfunction in physiological/pathophysiologi cal states. For example, functional tricuspid regurgitation, a common tricuspid valve disorder, could be caused by elevated right ventricular pressure due to pulmonary hypertension. In such patients, the geometry and the normal function of valve leaflets alter due to chronic pressure overload, which could cause remodeling responses in the ECM and change its structural components. To understand such a relation, we developed an experimental setup and measured alteration of leaflet microstructure in response to pressure increase in porcine tricuspid valves using the small angle light scattering technique. The anisotropy index, a measure of the fiber spread and distribution, was obtained and averaged for each region of the anterior, posterior, and septa! leaflet using four averaging methods. The average anisotropy indices (mean standard error) in the belly region of the anterior, posterior, and septal leaflets of non pressurized valves were found to be 12 +/- 2%, 21 +/- 3% and 12 +/- 1%, respectively. For the pressurized valve, the average values of the anisotropy index in the belly region of the anterior, posterior, and septal leaflets were 56 +/- 5%, 39 +/- 7% and 32 +/- 5%, respectively. Overall, the average anisotropy index was found to be higher for all leaflets in the pressurized valves as compared to the non-pressurized valves, indicating that the ECM fibers became more aligned in response to an increased ventricular pressure.Statement of SignificanceMechanics plays a critical role in development, regeneration, and remodeling of tissues. In the current study, we have conducted experiments to examine how increasing the ventricular pressure leads to realignment of protein fibers comprising the extracellular matrix (ECM) of the tricuspid valve leaflets. Like many other tissues, in cardiac valves, cell-matrix interactions and gene expressions are heavily influenced by changes in the mechanical microenvironment at the ECM/cellular level. We believe that our study will help us better understand how abnormal increases in the right ventricular pressure (due to pulmonary hypertension) could change the structural architecture of tricuspid valve leaflets and subsequently the mechanical microenvironment at the ECM/cellular level. (C) 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.