增殖性玻璃體視網膜病變 (Proliferative vitreoretinopathy PVR)程度越嚴重而使眼睛致盲機率性越高。此種現象與視網膜色素上皮細胞增生有關，目前最主要的治療方式為手術修補視網膜裂孔，但仍存在預後不佳以及產生不良副作用。增殖性玻璃體視網膜病變致病過程會產生許多發炎因子，例如表皮生長因子(epidermal growth factor)會誘導視網膜色素上皮細胞產生上皮間質細胞的轉化、移動和增生作用。之前研究顯示褪黑激素具有抗氧化、抗癌和轉移作用，本篇研究目的是探討褪黑激素是否抑制表皮生長因子誘導人類視網膜色素上皮ARPE-19細胞增生和移動作用及其分子機制。首先我們利用 MTT方式證實褪黑激素會抑制ARPE-19細胞生長呈現濃度線性關係。利用MTT方式、流式細胞儀和西方墨點法試驗證實褪黑激素抑制EGF誘導ARPE-19細胞生長、細胞週期停留G0/G1時期，並伴隨著cyclin D1減少及p21/p27增加。利用細胞移動實驗和蛋白酵素晶片證實褪黑激素抑制EGF誘導細胞移動作用是透過抑制組織蛋白S (CTSS)表現，此外褪黑激素也會抑制EGF誘導STAT3磷酸化作用。希望未來研究褪黑激素作為治療增殖性視網膜病變的重要的臨床應用。
Proliferative vitreoretinopathy (PVR) is the most common cause of surgical failure for rhegmatogenous retinal detachment. During the progression of PVR, multiple cytokines, such as EGF can induction of proliferation, epithelial-mesenchymal transitions (EMT) and migration of retinal pigment epithelium cells. Some reports showed that melatonin displays wide range of pharmacological properties including anti-oxidation, anti-tumor, anti-inflammatory and anti-angiogenesis effects. Therefore, the aim of the study was to clear the molecular mechanism of melatonin inhibit EGF induces cell proliferation and migration in ARPE-19 cell. Our results showed that melatonin inhibited ARPE-19 cell proliferation in a dose-dependent manner. Using a MTT assay and PI staining by flow cytometry, we found that melatonin inhibited the cell proliferation and increased to G0/G1 phase arrest, upregulated p21 and p27 proteins, and downregulated cyclin D1 proteins in the presence of EGF. Treatment of ARPE-19 cells with melatonin also inhibited EGF induced cell migration under non-cytotoxic concentrations. To identify the novel targets of melatonin, using the human proteinase antibody array analysis was performed, and the results suggested that the EGF treatment induced the expression of CTSS protein, and these inhibitory effects could be further enhanced by melatonin. However, melatonin reduced phosphorylation of signal transducer and activator of transcription 3 (STAT3) in EGF treated ARPE-19 cells. Based on the above, future research on melatonin as an important clinical application for the treatment of Proliferative vitreoretinopathy.
