- 學位論文
多酚類化合物對氧化型低密度脂蛋白引起視網膜色素上皮細胞傷害的抑制作用
The Inhibitory effect of Polyphenolic compounds in oxidized Low density lipoprotein induced Retinal Pigment Epithelium Cell damage
摘要
黃斑部就位於眼球後極部之正中心，是一層相當精細的組織層。在已開發國家，老年性黃斑部退化是50歲以上的老年人視力喪失的主要原因之一。最近有文獻指出老年性黃斑部的病人其Bruch’s membrane有膽固醇的聚集且可以內噬低密度脂蛋白及氧化型低密度脂蛋白。氧化型低密度脂蛋白的攝入可能會導致在巨噬細胞泡沫細胞的形成及細胞的死亡，但對是視網膜細胞的影響目前仍不清楚。 多酚被證實具有抗氧化及抗腫瘤的功效。在這次的研究，我們想要檢視多酚類化合物在氧化型低密度脂蛋白誘導視網膜色素上皮細胞 (ARPE-19) 傷害的影響。結果顯示，不管是由10μΜ CuSO4誘導的50μg/mL 或100μg/mL低密度脂蛋白都會誘導視網膜色素上皮細胞的凋亡及脂質的過氧化。而在處理catechin、 quercetin、 gallic acid、 protocatechuic acid、 delphindine 及 ferulic acid 培養24小時後，細胞凋亡及脂質過氧化的情形有輕微降低，除了ferulic acid 。我們選擇了最有效用的多酚類化合物： catechin、 quercetin 作DAPI 染色及流式細胞儀。結果顯示， catechin 及 quercetin 能夠減少凋亡細胞的產生。在 western blot 的結果顯示，凋亡相關的蛋白 (caspase3) 減少及抗凋亡相關的蛋白 (bcl-2) 增加。 綜合上述結果，證實 catechin 及 quercetin 能夠抑制氧化型低密度脂蛋白對視網膜色素細胞造成的死亡。
並列摘要
The macula is the central posterior portion of the retina, a quite fine organization level. In the developed world, age-related macular degeneration is the leading cause of irreversible blindness in people about 50 years of age or older. Recent scientific evidence shows that there is an age-related macular degeneration would cause accumulation of cholesterol in Bruch’s membrane to internalize low density lipoprotein (LDL) and oxidized LDL (oxLDL). Uptaking oxLDL would lead to foam cell formation or cell death in macrophage, but the effect of oxLDL is still remained unclear in retinal cell. Polyphenols had been demonstrated previously to possess antioxidative and antitumor promoting effects. In this study, we aimed to examine the effect of polyphenolic compounds in oxLDL induced retinal pigment epithelium cell (ARPE-19) damage. The results showed that 50μg/mL or 100μg/mL LDL induced by 10μ CuSO4 can induce ARPE cell apoptosis and lipid peroxidation. After pretreatment with catechin, quercetin, gallic acid, protocatechuic acid, delphindine and ferulic acid incubation 24 hours, the cell apoptosis and lipid peroxidation can be significantly reduced except of ferulic acid. We choose the most effective polyphenolic compounds: catechin and quercetin to do DAPI staining and flow cytometry. The results showed catechin and quercetin can reduced apopotic cells. In Western blot assay, the results showed that apoptotic-related protein (caspase3) reduced and anti-a apoptotic-related protein ( bcl-2) increased. In conclusion, the catechin and quercetin could inhibit oxLDL induced induced ARPE cell apoptosis.