Amico Carla, Yakimov Michail, Catania Maria Vincenza, Giuffrida Raffaella, Pistone Matteo, Enea Vincenzo
Department of R&D, SIFI SpA, Via Ercole Patti 36, 95020 Lavinaio, Italy.
Tissue Cell. 2004 Feb;36(1):1-12. doi: 10.1016/j.tice.2003.08.001.
Cyclooxygenases (COXs) are the key enzymes in the production of prostaglandins (PGs) and exist in two isoforms. Isoform 1 (COX-1) is constitutively expressed in most tissues, whereas cyclooxygenase-2 (COX-2) is rapidly induced by a variety of different stimuli. In this study, we have quantitatively analyzed mRNA expression of COX-1 and COX-2 and protein distribution during corneal reparative processes after wound. Total RNA was isolated from cornea samples of New Zealand rabbits that had been subjected to corneal wound by mechanical brush scraping. Quantification of RT-PCR results was made by using a DNA mimic approach. The localization and expression of the enzymes was studied by immunocytochemistry and Western blotting. In normal corneas COX-1 is expressed throughout the cornea in the whole tissue, while COX-2 is strongly expressed in stromal keratocytes. Following injury, COX-2 levels drastically increase and, at least in the epithelium, COX-2 becomes the predominant isoform of cyclooxygenases at an early stage of healing. Moreover, in the epithelium COX-2 is expressed predominantly by those cells close to the wound. These cells become migratory and move toward the injured area. In contrast, COX-1 levels remain unaffected in all corneal tissues. The system returns to the pre-injury state in about 24h. Thus, the expression of COX-2 in the corneal epithelium during wound repair is tightly regulated both temporally and spatially.
环氧化酶（COXs）是前列腺素（PGs）生成过程中的关键酶，有两种同工型。同工型1（COX-1）在大多数组织中组成性表达，而环氧化酶-2（COX-2）可被多种不同刺激快速诱导。在本研究中，我们定量分析了兔角膜创伤修复过程中环氧化酶-1和环氧化酶-2的mRNA表达及蛋白分布。从经机械刷刮造成角膜创伤的新西兰兔角膜样本中提取总RNA。采用DNA模拟法对逆转录聚合酶链反应（RT-PCR）结果进行定量分析。通过免疫细胞化学和蛋白质印迹法研究这些酶的定位和表达。在正常角膜中，COX-1在整个角膜组织中均有表达，而COX-2在基质角膜细胞中强烈表达。损伤后，COX-2水平急剧升高，至少在上皮细胞中，COX-2在愈合早期成为环氧化酶的主要同工型。此外，在上皮细胞中，COX-2主要由靠近伤口的细胞表达。这些细胞会迁移并朝着受伤区域移动。相比之下，所有角膜组织中的COX-1水平均未受影响。该系统在约24小时后恢复到损伤前状态。因此，伤口修复过程中角膜上皮细胞中COX-2的表达在时间和空间上均受到严格调控。
