Ngo Peter, Ramalingam Punitha, Phillips Jonathan A, Furuta Glenn T
Fellow in Pediatric Gastroenterology, Center for Experimental Therapeutics and Reperfusion Injury, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
Methods Mol Biol. 2006;341:103-9. doi: 10.1385/1-59745-113-4:103.
Mucosal tissues undergo contraction and relaxation on a continuous basis. In its normal state, the pliable intestinal tract is characterized by a rhythmic pattern of contractions controlled by its intrinsic neuronal innvervation. In chronic inflammatory diseases such as Crohn's disease, the intestine can become stiff and fibrotic, losing much of its normal motility. Although muscle fiber contraction accounts for much of this activity, contraction of nonmuscle tissue is constantly occurring in events associated with chronic inflammation, such as wound healing, scar formation, and tissue remodeling. However, the physiological and pathological mechanisms defining these events are not well defined. Tissue contraction is a dynamic event characterized by both intracellular and extracellular events. A number of cells, such as fibroblasts, epithelial cells, lymphocytes, and eosinophils, normally reside within the gastrointestinal tract. Additionally, the extracellular matrix is composed of a complex infrastructure that includes collagen and other molecules. The manner in which these two components interact is not certain, but the use of recent model systems has provided insights into these processes. The collagen lattice contraction assay provides a model for tissue contraction that takes advantage of the finding that cell-populated collagen hydrogels contract over time in a predictable, consistent manner. This model allows for investigation of the influence of specific agonists on the rate and extent of matrix contraction.
黏膜组织持续进行收缩和舒张。在正常状态下，柔韧的肠道以由其内在神经支配控制的节律性收缩模式为特征。在诸如克罗恩病等慢性炎症性疾病中，肠道会变得僵硬和纤维化，失去其大部分正常蠕动。虽然肌肉纤维收缩占了这种活动的大部分，但在与慢性炎症相关的事件中，如伤口愈合、瘢痕形成和组织重塑，非肌肉组织的收缩也在不断发生。然而，定义这些事件的生理和病理机制尚未明确。组织收缩是一个由细胞内和细胞外事件所表征的动态过程。许多细胞，如成纤维细胞、上皮细胞、淋巴细胞和嗜酸性粒细胞，通常存在于胃肠道内。此外，细胞外基质由包括胶原蛋白和其他分子在内的复杂结构组成。这两个组成部分相互作用的方式尚不确定，但最近模型系统的应用为这些过程提供了深入了解。胶原晶格收缩试验提供了一个组织收缩模型，该模型利用了这样一个发现，即细胞填充的胶原水凝胶会随着时间的推移以可预测、一致的方式收缩。该模型允许研究特定激动剂对基质收缩速率和程度的影响。
