Snyder Yuriy, Mann Fa Tony, Middleton John, Murashita Takashi, Carney John, Bianco Richard W, Jana Soumen
Department of Chemical and Biomedical Engineering, University of Missouri, 1406 Rollins Street, Columbia, MO 65211, USA.
Veterinary Health Center, University of Missouri, 900 East Campus Drive, Columbia, MO 65211-0001.
Appl Mater Today. 2024 Aug;39. doi: 10.1016/j.apmt.2024.102323. Epub 2024 Jul 16.
The clinical application of heart valve scaffolds is hindered by complications associated with the activation of valvular interstitial cell-like (VIC-like) cells and their transdifferentiation into myofibroblasts. This study aimed to examine several molecular pathway(s) that may trigger the overactive myofibroblast phenotypes in the implanted scaffolds. So, we investigated the influence of three molecular pathways - macrophage-induced inflammation, the TGF-β1-SMAD2, and WNT/β-catenin β on VIC-like cells during tissue engineering of heart valve scaffolds. We implanted electrospun heart valve scaffolds in adult sheep for up to 6 months in the right ventricular outflow tract (RVOT) and analyzed biomolecular (gene and protein) expression associated with the above three pathways by the scaffold infiltrating cells. The results showed a gradual increase in gene and protein expression of markers related to the activation of VIC-like cells and the myofibroblast phenotypes over 6 months of scaffold implantation. Conversely, there was a gradual increase in macrophage activity for the first three months after scaffold implantation. However, a decrease in macrophage activity from three to six months of scaffold tissue engineering suggested that immunological signal factors were not the primary cause of myofibroblast phenotype. Similarly, the gene and protein expression of factors associated with the TGF-β1-SMAD2 pathway in the cells increased in the first three months but declined in the next three months. Contrastingly, the gene and protein expression of factors associated with the WNT/β-catenin pathway increased significantly over the six-month study. Thus, the WNT/β-catenin pathway could be the predominant mechanism in activating VIC-like cells and subsequent myofibroblast phenotype.
心脏瓣膜支架的临床应用受到与瓣膜间质样（VIC样）细胞激活及其向肌成纤维细胞转分化相关的并发症的阻碍。本研究旨在探究可能触发植入支架中肌成纤维细胞过度活跃表型的几种分子途径。因此，我们在心脏瓣膜支架组织工程过程中，研究了三种分子途径——巨噬细胞诱导的炎症、TGF-β1-SMAD2和WNT/β-连环蛋白β对VIC样细胞的影响。我们将电纺心脏瓣膜支架植入成年绵羊的右心室流出道（RVOT）长达6个月，并通过支架浸润细胞分析与上述三种途径相关的生物分子（基因和蛋白质）表达。结果显示，在支架植入的6个月内，与VIC样细胞激活和肌成纤维细胞表型相关的标志物的基因和蛋白质表达逐渐增加。相反，在支架植入后的前三个月，巨噬细胞活性逐渐增加。然而，从支架组织工程的三个月到六个月，巨噬细胞活性下降，这表明免疫信号因子不是肌成纤维细胞表型的主要原因。同样，细胞中与TGF-β1-SMAD2途径相关的因子的基因和蛋白质表达在最初三个月增加，但在接下来的三个月下降。相比之下，在为期六个月的研究中，与WNT/β-连环蛋白途径相关的因子的基因和蛋白质表达显著增加。因此，WNT/β-连环蛋白途径可能是激活VIC样细胞及随后的肌成纤维细胞表型的主要机制。
