Department of Life Sciences, University of Modena and Reggio Emilia, 41125 Modena, Italy.
Department of Medical and Surgical Sciences for Children and Adults, University of Modena and Reggio Emilia, 41125 Modena, Italy.
Int J Mol Sci. 2022 Jan 29;23(3):1559. doi: 10.3390/ijms23031559.
Elastin represents the structural component of the extracellular matrix providing elastic recoil to tissues such as skin, blood vessels and lungs. Elastogenic cells secrete soluble tropoelastin monomers into the extracellular space where these monomers associate with other matrix proteins (e.g., microfibrils and glycoproteins) and are crosslinked by lysyl oxidase to form insoluble fibres. Once elastic fibres are formed, they are very stable, highly resistant to degradation and have an almost negligible turnover. However, there are circumstances, mainly related to inflammatory conditions, where increased proteolytic degradation of elastic fibres may lead to consequences of major clinical relevance. In severely affected COVID-19 patients, for instance, the massive recruitment and activation of neutrophils is responsible for the profuse release of elastases and other proteolytic enzymes which cause the irreversible degradation of elastic fibres. Within the lungs, destruction of the elastic network may lead to the permanent impairment of pulmonary function, thus suggesting that elastases can be a promising target to preserve the elastic component in COVID-19 patients. Moreover, intrinsic and extrinsic factors additionally contributing to damaging the elastic component and to increasing the spread and severity of SARS-CoV-2 infection are reviewed.
弹性蛋白是细胞外基质的结构成分，为皮肤、血管和肺部等组织提供弹性回缩。弹性生成细胞将可溶性原弹性蛋白单体分泌到细胞外空间，在那里这些单体与其他基质蛋白（如微纤维和糖蛋白）结合，并通过赖氨酰氧化酶交联形成不溶性纤维。一旦形成弹性纤维，它们就非常稳定，对降解具有很强的抵抗力，几乎没有周转率。然而，在某些情况下，主要与炎症有关，弹性纤维的蛋白水解降解增加可能导致具有重大临床相关性的后果。例如，在受严重影响的 COVID-19 患者中，大量中性粒细胞的募集和激活负责大量释放弹性蛋白酶和其他蛋白水解酶，导致弹性纤维的不可逆降解。在肺部，弹性网络的破坏可能导致肺功能的永久性损害，因此表明弹性酶可能是 COVID-19 患者中保留弹性成分的有希望的靶点。此外，还综述了内在和外在因素对弹性成分的破坏以及 SARS-CoV-2 感染的传播和严重程度的影响。
