角膜晶状体蛋白醛脱氢酶分类和功能的研究进展

Research Progress on the Classification and Function of Aldehyde Dehydrogenase as Corneal Crystallin

角膜中存在醛脱氢酶,其作为包含极高比例的角膜水溶性蛋白的代谢酶,属于角膜中含量最多的一种蛋白——角膜晶状体蛋白。醛脱氢酶是一种多功能蛋白质,既能维持晶状体透明度又具有酶活性。它极大地提高了角膜组织的透明度和折射能力,同时也在抑制角膜上皮细胞和角膜成纤维细胞的增殖、延长细胞周期、调节角膜上皮细胞鳞片状分化以及抗氧化应激等方面发挥着重要作用,尤其在抗氧化应激方面,醛脱氢酶可代谢体内内源性醛与外源性醛,避免有毒醛的积累,抵御机体氧化应激反应。它能够减轻紫外线辐射诱导产生的自由基和脂质过氧化产生的上百种有毒性醛对角膜造成的不可逆性损伤,对于维持角膜稳态具有重大意义。现将简要阐述醛脱氢酶作为角膜晶状体蛋白的起源与分类,着重总结其在角膜中的功能研究进展。

Aldehyde dehydrogenase exists in cornea.As a metabolic enzyme that contains a high proportion of corneal water-soluble proteins,it belongs to the most abundant protein in the cornea—corneal crystallins.Aldehyde dehydrogenase is a multifunctional protein,which not only maintains lens transparency but also has enzyme activity.It greatly improves the transparency and refractive power of corneal tissue.Simultaneously,aldehyde dehydrogenase also has effects on inhibiting the proliferation of corneal epithelial cells and corneal fibroblasts,extending the cell cycle,and regulating the scale-shaped differentiation of corneal epithelial cells.In addition,aldehyde dehydrogenase has the properties of anti-oxidative stress.It plays an important role in metabolizing endogenous and exogenous aldehydes in the body,avoiding the accumulation of toxic aldehydes,and resisting the body's oxidative stress response.Aldehyde dehydrogenase can reduce the irreversible damage to the cornea caused by free radicals and hundreds of toxic aldehydes produced by lipid peroxidation,which is of great significance in corneal homeostasis.This article will briefly describe the origin and classification of aldehyde dehydrogenase as corneal crystallin and focus on the research progress of its function in cornea.