P2X7 receptor expression after ischemia in the cerebral cortex of rats
P2X7 receptor expression after ischemia in the cerebral cortex of rats
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DOI：
10.1093/jnen/63.7.686
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发表时间：
2004-07-01
影响因子：
3.2
通讯作者：
Illes, P
中科院分区：
文献类型：
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作者：
Franke, H;Günther, A;Illes, P
在病理条件如缺血下从细胞来源释放的大量腺苷5 '-三磷酸（ATP）可激活P2 X和P2 Y型嘌呤受体。本研究采用永久性局灶性脑缺血模型，观察自发性高血压大鼠脑皮质P2 X1受体亚型的表达。与对照组相比，用针对细胞内P2 X受体C末端的抗体进行的免疫细胞化学显示，在右侧大脑中动脉闭塞（MCAO）后，梗死周围区域的标记细胞呈时间依赖性上调。用共聚焦激光扫描显微镜观察到的双重免疫荧光显示，缺血后P2 X受体在小胶质细胞（1天和4天后）、微管蛋白β III标记的神经元（4天和7天后）和胶质细胞酸性蛋白（GFAP）阳性星形胶质细胞（4天后）上的定位。在下面的实验中，详细研究了MCAO后4天发生的变化。对坏死区域周围皮质组织的Western印迹分析表明P2 X受体蛋白增加。免疫电子显微镜显示受体定位在突触（突触前），树突，以及神经元（突触后）和神经胶质细胞的核膜上。末端脱氧核苷酸转移酶介导的脱氧尿苷三磷酸-生物素缺口末端标记结合P2 X，受体免疫细胞化学表明凋亡细胞上的共表达。活化的caspase 3在GFAP阳性的星形胶质细胞上尤为明显。总之，目前的数据表明，缺血后，时间依赖性上调的P2 X，受体亚型的神经元和神经胶质细胞，并建议在体内脑缺血的病理生理学中的作用，这种受体。
Large amounts of adenosine 5'-triphosphate (ATP) released from cellular sources under pathological conditions such as ischemia may activate purinoceptors of the P2X and P2Y types. In the present study, the expression of the P2X, receptor-subtype in the brain cortex of spontaneously hypertensive rats was investigated using a permanent focal cerebral ischemia model. Immunocytochemistry with antibodies raised against the intracellular C-terminus of the P2X, receptor showed a time-dependent upregulation of labeled cells in the peri-infarct region after right middle cerebral artery occlusion (MCAO) in comparison to controls. Double immunofluorescence visualized with confocal laser scanning microscopy indicated the localization of the P2X, receptor after ischemia on microglial cells (after 1 and 4 days), on tubulin betaIII-labeled neurons (after 4 and 7 days), and on glial fibrillary acidic protein (GFAP)-positive astrocytes (after 4 days). In the following experiments, changes occurring 4 days after MCAO were investigated in detail. Western blot analysis of the cortical tissue around the area of necrosis indicated an increase in the P2X, receptor protein. Immunoelectron microscopy revealed the receptor localization on synapses (presynaptically), on dendrites, as well as on the nuclear membrane of neurons (postsynaptically) and glial cells. Terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labeling in combination with P2X, receptor immunocytochemistry indicated a co-expression on the apoptotic cells. Active caspase 3 was especially observed on GFAP-positive astrocytes. In conclusion, the present data demonstrate a postischemic, time-dependent upregulation of the P2X, receptor-subtype on neurons and glial cells and suggest a role for this receptor in the pathophysiology of cerebral ischemia in vivo.