Institute of Animal Physiology and Genetics, Academy of Sciences of the Czech Republic, Liběchov, Czech Republic.
Faculty Hospital Královské Vinohrady, Prague, Czech Republic.
Photochem Photobiol. 2016 Sep;92(5):720-7. doi: 10.1111/php.12612. Epub 2016 Aug 25.
Tissue inhibitors of metalloproteinases (TIMPs) are the major endogenous regulators of metalloproteinase activity in tissues. TIMPs are able to inhibit activity of all known matrix metalloproteinases (MMPs) and thus participate in controlling extracellular matrix synthesis and degradation. We showed previously elevated expressions of MMPs in the rabbit corneal epithelium upon UVB exposure and suggested that these enzymes might be involved in corneal destruction caused by excessive proteolysis. The aim of this study was to investigate TIMPs in the corneal epithelium after UV irradiation using immunohistochemical and biochemical methods. We found that as compared to control rabbit corneas where relatively high levels of TIMPs were present in the epithelium, repeated irradiation of the cornea with UVB rays (not with UVA rays of similar doses) significantly decreased TIMPs in corneal epithelial cells. The results of this study point to the suggestion that the decrease in TIMPs in the corneal epithelium after UVB irradiation contributes to increased proteolytic activity of MMPs in UVB-irradiated corneal epithelium found previously.
组织金属蛋白酶抑制剂（TIMPs）是组织中金属蛋白酶活性的主要内源性调节剂。TIMP 能够抑制所有已知基质金属蛋白酶（MMPs）的活性，从而参与控制细胞外基质的合成和降解。我们之前曾表明，在 UVB 暴露后兔角膜上皮中 MMPs 的表达升高，并提出这些酶可能参与了由过度蛋白水解引起的角膜破坏。本研究旨在使用免疫组织化学和生化方法研究 UV 照射后角膜上皮中的 TIMPs。我们发现，与对照组兔角膜相比，其中上皮中存在相对高水平的 TIMPs，重复用 UVB 射线照射角膜（而不是用相同剂量的 UVA 射线）会显著降低角膜上皮细胞中的 TIMPs。本研究的结果表明，在 UVB 照射后角膜上皮中 TIMPs 的减少有助于增加之前在 UVB 照射的角膜上皮中发现的 MMPs 的蛋白水解活性。
