Iwatake Akira, Murakami Akira, Ebihara Nobuyuki
Department of Ophthalmology, Juntendo University School of Medicine, Tokyo, Japan.
Department of Ophthalmology, Juntendo University Urayasu Hospital, 2-1-1 Tomioka, Urayasu, Chiba, 279-0021, Japan.
Jpn J Ophthalmol. 2018 Jan;62(1):92-100. doi: 10.1007/s10384-017-0541-x. Epub 2017 Nov 1.
Sterile ulceration is frequently observed in the cornea following persistent corneal epithelial damage. We examined the effect of alarmins released by necrotic corneal epithelial cells (HCE) on the production of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) by corneal fibroblasts.
IL-1α and high-mobility group box 1 protein (HMGB1) released into the supernatant derived from necrotic HCE cells were measured with enzyme-linked immunosorbent assay (ELISA). MMPs and TIMPs produced by corneal fibroblasts, stimulated with the supernatant from necrotic HCE cells, were analyzed and measured with protein array and ELISA. To investigate dynamic expression of alarmins in the corneal epithelium, we used immunohistochemistry to observe the expression of human IL-1α in the corneal epithelium of human IL-1α Tg mice with or without cryopexy. We also investigated the expression of MMPs in corneal stroma of the mice treated with cryopexy, using RT-PCR.
We detected IL-1α and HMGB-1 in the supernatant of necrotic HCE cells. These supernatants increased the expression of MMP-3 and MMP-1, and decreased that of TIMP-1 and TIMP-2 in human corneal fibroblasts. Almost always these were inhibited by IL-1 receptor antagonist. Recombinant IL-1α increased the production MMP-3 and MMP-1 in corneal fibroblasts. After cryopexy of the epithelium of human IL-1α Tg mice, the expression of human IL-1α was recognized in the cytoplasm but not nucleus of epithelial cells. The level of MMP-3 and MMP-1 mRNAs was elevated in the corneal stroma in mice treated with cryopexy.
Alarmins, especially IL-1α, released from necrotic HCE cells may play an important role in the expression of MMPs and TIMPs by corneal fibroblast, resulting in sterile ulceration.
在持续性角膜上皮损伤后，角膜中常观察到无菌性溃疡。我们研究了坏死角膜上皮细胞（HCE）释放的警报素对角膜成纤维细胞产生基质金属蛋白酶（MMPs）和金属蛋白酶组织抑制剂（TIMPs）的影响。
采用酶联免疫吸附测定（ELISA）法检测坏死HCE细胞上清液中释放的白细胞介素-1α（IL-1α）和高迁移率族蛋白B1（HMGB1）。用蛋白质芯片和ELISA法分析并检测坏死HCE细胞上清液刺激的角膜成纤维细胞产生的MMPs和TIMPs。为研究警报素在角膜上皮中的动态表达，我们用免疫组织化学法观察了有或无冷冻治疗的人IL-1α转基因小鼠角膜上皮中人IL-1α的表达。我们还用逆转录-聚合酶链反应（RT-PCR）研究了冷冻治疗小鼠角膜基质中MMPs的表达。
我们在坏死HCE细胞的上清液中检测到IL-1α和HMGB-1。这些上清液增加了人角膜成纤维细胞中MMP-3和MMP-1的表达，降低了TIMP-1和TIMP-2的表达。这些变化几乎总是被IL-1受体拮抗剂抑制。重组IL-1α增加了角膜成纤维细胞中MMP-3和MMP-1的产生。在人IL-1α转基因小鼠上皮进行冷冻治疗后，在上皮细胞的细胞质而非细胞核中检测到了人IL-1α的表达。冷冻治疗小鼠的角膜基质中MMP-3和MMP-1 mRNA水平升高。
坏死HCE细胞释放的警报素，尤其是IL-1α，可能在角膜成纤维细胞表达MMPs和TIMPs中起重要作用，从而导致无菌性溃疡。
