Autophagy was activated in injured astrocytes and mildly decreased cell survival following glucose and oxygen deprivation and focal cerebral ischemia
Autophagy was activated in injured astrocytes and mildly decreased cell survival following glucose and oxygen deprivation and focal cerebral ischemia
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自噬在受损的星形胶质细胞中被激活，并在葡萄糖和氧气剥夺以及局灶性脑缺血后轻度降低细胞存活率
DOI：
10.4161/auto.6.6.12573
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发表时间：
2010-08-16
期刊：
影响因子：
13.3
通讯作者：
Zhang, Hui-Ling
中科院分区：
文献类型：
--
作者：
Qin, Ai-Ping;Liu, Chun-Feng;Zhang, Hui-Ling
本研究评估了星形胶质细胞的自噬激活及其对脑缺血缺氧引起的星形胶质细胞损伤的贡献。大鼠大脑中动脉永久性闭塞（pMCAO）诱发局灶性脑缺血。体外培养的原代星形胶质细胞缺氧是由氧糖剥夺（OGD）诱导的。用星形胶质细胞标记物胶质纤维酸性蛋白（GFAP）评估星形胶质细胞的改变。用透射电子显微镜（TEM）检查星形胶质细胞中自噬体的形成。通过免疫印迹检查自噬相关蛋白的表达。通过用 3-甲基腺嘌呤 (3-MA) 或巴弗洛霉素 A1 (Baf) 药理抑制自噬来评估自噬在 OGD 或局灶性脑缺血诱导的星形胶质细胞死亡中的作用。结果显示，pMCAO 后 3-12 小时，梗死脑区的 GFAP 染色减少。脑缺血或 OGD 诱导星形胶质细胞自噬激活，自噬体和自溶酶体以及单丹磺酰尸胺 (MDC) 标记的囊泡形成增加证明了这一点；微管相关蛋白 1 轻链 3 (LC3-II) 产量增加； Beclin 1、溶酶体相关膜蛋白 2 (LAMP2) 和溶酶体组织蛋白酶 B 表达的上调；原代星形胶质细胞中细胞保护性 Bcl-2 蛋白水平降低。 3-MA抑制OGD诱导的LC3-II的增加和Bcl-2的减少。此外，3-MA 和 Baf 轻微但显着地减弱了 OGD 诱导的星形胶质细胞死亡。 pMCAO后12小时，3-MA还显着增加了缺血皮质核心中GFAP阳性细胞的数量和GFAP蛋白水平。这些结果表明，缺血或缺氧诱导的自噬/溶酶体途径激活可能至少部分导致星形胶质细胞的缺血性损伤。
The present study evaluated autophagy activation in astrocytes and its contribution to astrocyte injury induced by cerebral ischemia and hypoxia. Focal cerebral ischemia was induced by permanent middle cerebral artery occlusion (pMCAO) in rats. In vitro hypoxia in cultured primary astrocytes was induced by the oxygen-glucose deprivation (OGD). Alterations of astrocytes were evaluated with astroglia markers glial fibrillary acidic protein (GFAP). The formation of autophagosomes in astrocytes was examined with transmission electron microscopy (TEM). The expression of autophagy-related proteins were examined with immunoblotting. The role of autophagy in OGD or focal cerebral ischemia-induced death of astrocytes was assessed by pharmacological inhibition of autophagy with 3-methyladenine (3-MA) or bafilomycin A1 (Baf). The results showed that GFAP staining was reduced in the infarct brain areas 3-12 h following pMCAO. Cerebral ischemia or OGD induced activation of autophagy in astrocytes as evidenced by the increased formation of autophagosomes and autolysosomes and monodansylcadaverine (MDC)-labeled vesicles; the increased production of microtubule-associated protein 1 light chain 3 (LC3-II); the upregulation of Beclin 1, lysosome-associated membrane protein 2 (LAMP2) and lysosomal cathepsin B expression; and the decreased levels of cytoprotective Bcl-2 protein in primary astrocytes. 3-MA inhibited OGD-induced the increase in LC3-II and the decline in Bcl-2. Furthermore, 3-MA and Baf slightly but significantly attenuated OGD-induced death of astrocytes. 3-MA also significantly increased the number of GFAP-positive cells and the protein levels of GFAP in the ischemic cortex core 12 h following pMCAO. These results suggest that ischemia or hypoxia-induced autophagic/lysosomal pathway activation may at least partly contribute to ischemic injury of astrocytes.