摘要
缺血性中風在台灣地區為國人常見的類型，約佔所有中風的70%，是造成中老年人殘障、失能主要原因，因此找到有效治療病情的藥物乃當務之急。間質幹細胞 (mesenchymal stem cell，簡稱MSC) 已被證實具有旁分泌的機制來保護神經組織，藉由釋放神經促進因子，例如血管內皮生長因子、腦源性神經營養因子等以增加內生性神經再生機制。然而，MSC對於缺血缺氧的保護作用是否透過改變細胞死亡過程，目前機轉尚不明確。本實驗使用MSC與神經元細胞共同培養法，探討其對於多巴胺神經元 (PC12 細胞) 暴露在缺氧缺葡萄糖環境以模擬活體腦中風的壓力及其保護機制評估。實驗共分為四個組別: 正常控制組、控制組與MSC共同培養測試組、缺血再灌流損傷對照組及缺血再灌流損傷與MSC共同培養治療組。與控制組做比較，多巴胺神經元細胞遭受缺血再灌流損傷後，細胞明顯皺縮及死亡、DNA片斷化、蛋白酶caspase-3 活化及大量的細胞週期Sub-G1的表現。經MSC治療後，細胞存活率明顯提升、細胞凋亡蛋白酶Caspase-3表現量減少、DNA片段化及Sub-G1表現量顯著下降。本實驗證實MSC對於缺血性神經元凋亡具有顯著的改善作用。
關鍵詞: 缺血再灌流損傷、間質幹細胞、細胞凋亡
Abstract
In Taiwan, about 70 % of stroke is cerebrovascular ischemic and may cause the handicap or disability among the middle-aged and elderly. Therefore, it is imperative to find an effective answer to the disease. As a result, it has been confirmed that the mesenchymal stem cells (MSC) paracrine effects by releasing the nerve promoting factors like epidermal growth factor (EGF) or brain-derived neurotrophic factor (BDNF), protected the nerve tissue to enhance the endogenous nerve regeneration. However, whether the effects of MSC on protecting ischemia-hypoxia injury alter the apoptosis is indeterminate. In this experiment, the co-culture of MSC and the oxygen-glucose deprivation (OGD) PC12 neuron cells were employed to determine the alleviation of the stroke stress and the protection mechanism. The experiment groups were: control group (control-PC12); control with MSC co-culture group (control-PC12+MSC); OGD group (OGD-PC12); OGD with MSC co-culture group (OGD-PC12+MSC). In the OGD group, the PC12 cells were significantly shrank and died; the DNA fragmented; caspase-3 regenerated; the Sub-G1 phase greatly increased. Obviously, with the MSC co-culture, the PC12 cell survival rate apparently advanced; caspase-3 decreased; DNA fragmentation and Sub-G1 expression prominently reduced. Thence, the neuroprotective MSC suppressed the OGD-induced PC12 cell apoptosis.
Keywords: Oxygen-glucose Deprivation Injury, Mesenchymal Stem Cell, Apoptosis