Gilbert Thomas W, Stewart-Akers Ann M, Sydeski Jennifer, Nguyen Tan D, Badylak Stephen F, Woo Savio L-Y
McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
Tissue Eng. 2007 Jun;13(6):1313-23. doi: 10.1089/ten.2006.0318.
Extracellular matrix scaffolds derived from porcine small intestinal submucosa (SIS-ECM) have been shown to promote the formation of site-specific tissue in a number of preclinical animal studies. However, this constructive remodeling process requires that the scaffold be subjected to a site-specific mechanical environment. The specific quantitative effects of mechanical loading on the gene expression patterns of fibroblasts seeded on SIS-ECM are unknown and yet very important in the tissue remodeling process. The objective of the present study was to evaluate the expression of collagen type I (Col I), collagen type III (Col III), smooth muscle actin (SMA), tenascin-C (TN-C), matrix metalloprotease-2 (MMP-2), matrix metalloprotease-9 (MMP-9), transforming growth factor-beta1 (TGF-beta1), and transforming growth factor-beta3 (TGF-beta3) by fibroblasts subjected to various magnitudes (0%, 5%, 10%, and 15%) and frequencies (0.1 Hz, 0.3 Hz, and 0.5 Hz) of stretch. A new cyclic-stretching tissue culture (CSTC) system was developed. This system consists of eight independently controlled culture chambers that can be operated in a sterile incubator. Each chamber includes a load cell so that the load in each scaffold can be monitored. It was found that different stretching regimens led to complex and distinctive patterns of gene expression by fibroblasts seeded onto SIS-ECM. In general, the fibroblasts increased expression of Col I up to 5-fold and decreased that of Col III with increased frequency of stretch. In addition, the fibroblasts exhibited a contractile phenotype with increased expression of SMA, TN-C, and TGF-beta1. These findings support the concept that the mechanical environment of a remodeling ECM scaffold may have substantial effects on the behavior of cells within the scaffold and contribute to the site-specific tissue remodeling that has been observed in in vivo studies.
在多项临床前动物研究中，源自猪小肠黏膜下层的细胞外基质支架（SIS - ECM）已被证明可促进特定部位组织的形成。然而，这种建设性的重塑过程要求支架处于特定部位的力学环境中。机械加载对接种于SIS - ECM上的成纤维细胞基因表达模式的具体定量影响尚不清楚，但在组织重塑过程中却非常重要。本研究的目的是评估接种于SIS - ECM上的成纤维细胞在受到不同幅度（0%、5%、10%和15%）和频率（0.1 Hz、0.3 Hz和0.5 Hz）拉伸时，I型胶原（Col I）、III型胶原（Col III）、平滑肌肌动蛋白（SMA）、腱生蛋白 - C（TN - C）、基质金属蛋白酶 - 2（MMP - 2）、基质金属蛋白酶 - 9（MMP - 9）、转化生长因子 - β1（TGF - β1）和转化生长因子 - β3（TGF - β3）的表达情况。开发了一种新的循环拉伸组织培养（CSTC）系统。该系统由八个独立控制的培养室组成，可在无菌培养箱中运行。每个培养室都包括一个力传感器，以便监测每个支架中的负载。研究发现，不同的拉伸方案导致接种于SIS - ECM上的成纤维细胞呈现复杂且独特的基因表达模式。一般来说，随着拉伸频率增加，成纤维细胞中Col I的表达增加高达5倍，而Col III的表达则降低。此外，成纤维细胞表现出收缩表型，SMA、TN - C和TGF - β1的表达增加。这些发现支持了这样一种观点，即重塑的ECM支架的力学环境可能对支架内细胞的行为产生重大影响，并有助于体内研究中观察到的特定部位组织重塑。
