Pelosi Paolo, Rocco Patricia R M, Negrini Daniela, Passi Alberto
Servizio di Anestesia B, Department of Ambient, Health and Safety, University of Insubria, and Ospedale di Circolo e Fondazione Macchi, Varese, Italy.
An Acad Bras Cienc. 2007 Jun;79(2):285-97. doi: 10.1590/s0001-37652007000200010.
The extracellular matrix is composed of a three-dimensional fiber mesh filled with different macromolecules such as: collagen (mainly type I and III), elastin, glycosaminoglycans, and proteoglycans. In the lung, the extracellular matrix has several functions which provide: 1) mechanical tensile and compressive strength and elasticity, 2) low mechanical tissue compliance contributing to the maintenance of normal interstitial fluid dynamics, 3) low resistive pathway for an effective gas exchange, d) control of cell behavior by the binding of growth factors, chemokines, cytokines and the interaction with cell-surface receptors, and e) tissue repair and remodeling. Fragmentation and disorganization of extracellular matrix components comprises the protective role of the extracellular matrix, leading to interstitial and eventually severe lung edema. Thus, once conditions of increased microvascular filtration are established, matrix remodeling proceeds fairly rapidly due to the activation of proteases. Conversely, a massive matrix deposition of collagen fiber decreases interstitial compliance and therefore makes the tissue safety factor stronger. As a result, changes in lung extracellular matrix significantly affect edema formation and distribution in the lung.
细胞外基质由充满不同大分子的三维纤维网组成，这些大分子包括：胶原蛋白（主要是I型和III型）、弹性蛋白、糖胺聚糖和蛋白聚糖。在肺中，细胞外基质具有多种功能，包括：1）提供机械拉伸、压缩强度和弹性；2）具有低机械组织顺应性，有助于维持正常的间质液动力学；3）为有效的气体交换提供低阻力途径；4）通过生长因子、趋化因子、细胞因子的结合以及与细胞表面受体的相互作用来控制细胞行为；5）进行组织修复和重塑。细胞外基质成分的碎片化和无序化破坏了细胞外基质的保护作用，导致间质性肺水肿，最终发展为严重肺水肿。因此，一旦微血管滤过增加的情况形成，由于蛋白酶的激活，基质重塑会相当迅速地进行。相反，大量胶原纤维的基质沉积会降低间质顺应性，从而使组织安全系数增强。结果，肺细胞外基质的变化会显著影响肺水肿在肺中的形成和分布。
