二十碳五烯酸透過調節粒線體功能防止過氧化氫對C2C12肌原母細胞誘導之細胞死亡

Functional Modulation of Mitochondria by Eicosapentaenoic Acid Provides Protection against Hydrogen Peroxide-Induced Cell Death to C2C12 Myoblast

賴冠宇(Guan-Yu Lai)

指導教授 ： 謝榮鴻

臺北醫學大學/公共衛生暨營養學院/保健營養學研究所/碩士(2014年)

摘要

肌原母細胞（myoblast）為活化的肌原前驅細胞，氧化壓力為造成骨骼肌細胞損傷與死亡的因子之一，且細胞死亡機制與粒線體存有密切關係。已有研究指出n-3多元不飽和脂肪酸具有提升粒線體功能之效果，其中eicosapentaenoic acid（EPA）已於許多動物模式研究中證實可減少發炎介質導致的肌肉萎縮及退化，故本研究將探討EPA是否可增加C2C12肌原母細胞粒線體生合成與功能，進而增加肌原母細胞於氧化壓力下之存活率。給予1 μM oligomycin後細胞之粒線體功能降低，同時伴隨粒線體膜電位增加與細胞內reactive oxygen species (ROS)含量降低，而細胞存活率卻出現顯著下降，此結果表示降低粒線體功能足以導致細胞死亡。細胞給予25及50 μM EPA後其粒線體生合成指標皆出現顯著增加；介入25 μM EPA之粒線體功能僅顯著增加基礎耗氧量，介入50 μM EPA之粒線體功能各項指標皆顯著增加。細胞預先給予25及50 μM EPA後皆可顯著減少H2O2所造成的細胞死亡，其除了與EPA提升粒線體生合成與功能有關，也因EPA可顯著增加粒線體膜電位。給予25及50 μM EPA，細胞內ROS含量皆無顯著改變，而預先給予25及50 μM EPA後也皆無法改善H2O2所造成的細胞內ROS含量增加。Oligomycin造成的細胞死亡指出改變粒線體功能足以影響細胞存活率，而EPA雖無抗氧化能力，但可透過增加粒線體生合成、功能及膜電位以減少H2O2所誘導的細胞死亡。

關鍵字

肌原母細胞 ； 二十碳五烯酸 ； 粒線體生合成 ； 粒線體功能 ； 粒線體膜電位

並列摘要

Mitochondria are central executers of cell death signaling. Beneficial effects on mitochondrial biogenesis and function of n-3 polyunsaturated fatty acids（ PUFAs ） have been reported. The protective potential of eicosapentaenoic acid（EPA） on C2C12 myoblasts exposed to oxidative stress was investigated in this study. C2C12 myoblasts treated with 25 and 50 μM EPA were detected significantly increased mitochondrial biogenesis markers. 50 μM EPA can increase all indices of mitochondrial function, but 25 μM EPA only increased the basal oxygen consumption rate in mitochondrial function. There were significant repressive effects on hydrogen peroxide (H2O2)-induced cell death with 25 and 50 μM EPA pretreatment. Significantly increased membrane potentials were detected in cells pretreated with 25 and 50 μM EPA compared to H2O2-treated cells. However, C2C12 myoblasts treated with EPA were found no significant difference in intracellular reactive oxygen species (ROS), and there is no decreased ROS in C2C12 myoblasts pretreated with EPA followed by H2O2 treatment. The EPA provided a protective effect against H2O2-induced cell death, which is due to the increased mitochondrial content and function through influencing mitochondrial membrane potential.

並列關鍵字

myoblast ； eicosapentaenoic acid ； mitochondrial biogenesis ； mitochondrial function ； mitochondrial membrane potential

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