【摘要】：目的：本實驗旨在觀察慢性低灌注腦缺血(2VO)大鼠海馬CA1區(qū)自噬水平變化對神經(jīng)元凋亡的影響,探討2VO大鼠海馬CA1區(qū)GABAB受體、GABAA受體和自噬相互關(guān)聯(lián)及其可能的作用機制。方法：采用大鼠雙側(cè)頸總動脈永久性結(jié)扎慢性低灌注腦缺血模型；應(yīng)用水迷宮實驗評價其認知功能的變化：采用免疫熒光技術(shù)檢測自噬表達和分布的變化；采用HE染色觀察海馬形態(tài)學(xué)改變及CA1區(qū)神經(jīng)元丟失情況；TUNEL染色檢測神經(jīng)元凋亡；Western blot檢測相關(guān)蛋白的變化：①LC3-Ⅱ、p-mTOR、Beclin 1等自噬相關(guān)蛋白；Bcl-2和cleaved caspase-3等凋亡相關(guān)蛋白；③GABAA受體；④Akt、GSK-3p和ERK1/2；⑤線粒體和細胞膜上縫隙連接蛋白CX43、 CX36;⑥自噬體轉(zhuǎn)運相關(guān)蛋白MAPK8IP1/JIP1、DUSP1/MKP1;⑦溶酶體相關(guān)蛋白LAMP-1、cathepsin L。結(jié)果：2VO模型組大鼠空間學(xué)習(xí)記憶能力受損；海馬皺縮、CA1區(qū)神經(jīng)元數(shù)量顯著減少、自噬水平顯著增加且分布紊亂；Bcl-2/Bax比率降低,cleaved caspase-3增多：GABAA受體膜表達減少；線粒體和胞膜上的CX43和CX36表達增加。GABAB受體激動劑baclofen可明顯減輕神經(jīng)元損傷。同時,baclofen可上調(diào)Bcl-2/Bax比率、激活A(yù)kt、GSK-3β和ERK而抑制細胞破壞性自噬。另外,我們還發(fā)現(xiàn)baclofen可改善慢性低灌注腦缺血引起的GABAA受體膜表達減少,進而下調(diào)細胞膜及線粒體膜CX43和CX36的表達,促進保護性自噬。我們的實驗還發(fā)現(xiàn),baclofen可改善2VO誘導(dǎo)大鼠海馬CA1區(qū)自噬體逆向軸突運輸障礙和溶酶體功能受損,其具體機制還有待進一步研究。結(jié)論：在慢性低灌注腦缺血情況下,激動GABAB受體通過雙重調(diào)節(jié)自噬、改善自噬體逆向轉(zhuǎn)運障礙、恢復(fù)溶酶體功能而減輕神經(jīng)元損傷及認知功能障礙。
[Abstract]:Aim: to investigate the effect of autophagy on apoptosis of hippocampal CA1 in rats with chronic hypoperfusion cerebral ischemia (2VO), and to explore the relationship among GABAB receptor, GABAA receptor and autophagy in CA1 area of 2VO rats and its possible mechanism. Methods: the rat model of chronic hypoperfusion cerebral ischemia was established by permanent ligation of bilateral common carotid artery, the changes of cognitive function were evaluated by water maze test, and the changes of autophagy expression and distribution were detected by immunofluorescence technique. Hippocampal morphological changes and neuronal loss in CA1 region were observed by HE staining, and apoptotic; Western blot was detected by TUNEL staining: 1autophagy related proteins such as LC3- 鈪，

本文編號：2335855