- 學位論文
魚藤酮所誘發之帕金森氏症模式中咖啡因對自噬作用之影響
Caffeine altered autophagy in rotenone-induced Parkinson’s disease model
摘要
帕金森氏症 (Parkinson’s disease) 為一種常見之神經退化疾病，肇因於中腦多巴胺神經元之退化、死亡。魚藤酮 (rotenone) 為一種植物性毒化物，能抑制粒線體之電子傳遞鏈，常應用做為農、漁業用藥，研究發現可能與帕金森氏症有關。本研究之目的在探討咖啡因 (caffeine) 能否調控細胞的自噬作用 (autophagy)，並降低魚藤酮暴露對於多巴胺神經元之傷害。本研究結果顯示，在SH-SY5Y細胞株之離體細胞培養帕金森氏症模式中，1 nM之魚藤酮即對SH-SY5Y細胞產生顯著的細胞毒性。而在10 nM之魚藤酮暴露模式中，給予10 μM之咖啡因的前處理能顯著增加細胞存活率，同時也能觀測到細胞自噬作用之表現上升、細胞凋亡情形顯著減少。在細胞生化結果顯示咖啡因前處理可促進ATP的生成，但不影響NF-κB p65、p-Akt、p38-MAPK、p85-PI3K的表現量。這顯示當SH-SY5Y細胞在受到魚藤酮的傷害時，咖啡因前處理可能藉由促進ATP合成，來提高細胞代謝能量的緩衝能力，以提供細胞進行自噬作用的能量需求。在動物模式中，以持續一週皮下注射1 mg/kg之魚藤酮所誘導之帕金森氏症大鼠模式中，預先並持續給予10 mg/kg口服咖啡因的組別，其運動行為能力高於單純給予魚藤酮之組別；而在停止魚藤酮處理18天後，預先並持續給予口服咖啡因之組別，其運動能力的恢復情況也高於單純給予魚藤酮之動物。本研究證實在魚藤酮所誘發之帕金森氏症模式中，咖啡因的前處理能增加細胞自噬作用的表現、提高多巴胺神經元的存活率，並能增加動物運動行為能力，達到降低或預防因接觸魚藤酮可能造成的風險與傷害。
並列摘要
Parkinsons’ disease (PD) is one of the common neurodegenerative diseases caused by the dopaminergic neurons lost in midbrain. Rotenone (ROT), a plant toxin, is able to inhibit the electron transport chain in mitochondria, and highly used in agriculture and fisheries. Previous studies indicated that rotenone exposure might be associated with Parkinson's disease. This study was conducted to investigate the effects of CAF on autophagy in ROT-induced PD model. The result indicated that as ROT concentration more than 1 nM, the viability of SH-SY5Y cells decrease significantly. In 10 nM ROT induced PD cell model, pretreated with 10 μM of CAF can increase SH-SY5Y cell viability, autophagy expression, and decrease cell apoptosis. In addition, in ROT induce PD cell model, CAF has few effects on NF-κB p65, p-Akt, p38-MAPK, and p85-PI3K pathway to upregulate autophagy. The results indicated dopaminergic cell pretreated with CAF could promote the ATP generation and that may facilitate autophagy to increase the cell viability. In vivo, the locomotion result showed SD rats pretreated with CAF (10 mg/kg daily, P.O.) in ROT (1 mg/kg daily for 1 week, S.C.) induced PD animal model was better than another group without pretreated CAF. After exposure ROT, the situation of recovery from bradykinesia in daily CAF treated group was more obvious than another. In conclusion, in ROT induce PD model, CAF could facilitate autophagy, increase cell viability and animal locomotion. The results represent that CAF has potential effect to decline or postpone the injury from ROT.