Matrix metalloproteinase 9 regulates cell death following pilocarpine-induced seizures in the developing brain
Matrix metalloproteinase 9 regulates cell death following pilocarpine-induced seizures in the developing brain
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DOI：
10.1016/j.nbd.2012.06.023
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发表时间：
2012-12-01
影响因子：
6.1
通讯作者：
Ikonomidou, Chrysanthy
中科院分区：
文献类型：
--
作者：
Hoehna, Yvonne;Uckermann, Ortrud;Ikonomidou, Chrysanthy
基质金属蛋白酶（MMP）参与组织修复、细胞死亡和形态发生。我们研究了明胶酶MMP-2和MMP-9在发育中的大脑中长时间癫痫发作诱导的神经元死亡的发病机制中的作用。7日龄大鼠、MMP-9敲除小鼠和过表达MMP-9的转基因大鼠接受250 mg/kg的毛果芸香碱腹腔注射以诱导癫痫发作。6-72 h后处死，分离不同脑区组织，采用实时荧光定量PCR或Western blocks检测MMP-9 mRNA和蛋白表达，并进行TUNEL染色、免疫组化和原位酶谱分析。我们发现毛果芸香碱诱导癫痫发作后24小时，TUNEL阳性细胞的数量增加，最明显的皮质区和齿状回，丘脑不太明显。在6-24小时，MMP-9 mRNA水平显示出显着升高相比，假处理的对照组，这种影响解决了48小时，而MMP-2 mRNA水平保持稳定。皮质明胶分解活性，监测原位酶谱，增强匹罗卡品诱导癫痫发作。MMP抑制剂GM 6001改善毛果芸香碱诱导的幼鼠癫痫发作后的细胞死亡。MMP-9基因敲除小鼠对脑损伤的敏感性较低。过表达MMP-9的转基因大鼠与野生型大鼠一样容易受到脑损伤的影响。我们的研究结果表明，MMP-9的显着贡献毛果芸香碱诱导癫痫发作后，在发育中的大脑细胞死亡。如Western印迹分析所示，MMP-9活化可能与Erk/CREB途径的活化有关。这些发现暗示MMP-9参与了发育中大脑癫痫发作后脑损伤的病理生理学。(c)2012 Elsevier Inc. All rights reserved.
Matrix metalloproteinases (MMPs) are involved in tissue repair, cell death and morphogenesis. We investigated the role of the gelatinases MMP-2 and MMP-9 in the pathogenesis of neuronal death induced by prolonged seizures in the developing brain. Seven-day-old rats, MMP-9 knockout mice and transgenic rats overexpressing MMP-9 received intraperitoneal injections of pilocarpine, 250 mg/kg, to induce seizures. After 6-72 h pups were sacrificed, tissue from different brain regions was isolated and expression of MMP-9 mRNA and protein was analyzed by real-time PCR or Western bloc Additionally, brains were fixed and processed for TUNEL-staining, immuno-histochemistry and in situ zymography. We found increased numbers of TUNEL-positive cells 24 h after pilocarpine-induced seizures, most pronounced in cortical areas and the dentate gyrus, and less pronounced in thalamus. At 6-24 h, MMP-9 mRNA levels showed significant elevation compared to sham-treated controls; this effect resolved by 48 h, whereas MMP-2 mRNA levels remained stable. Cortical gelatinolytic activity, monitored by in situ zymography, was enhanced following pilocarpine-induced seizures. The MMP inhibitor GM 6001 ameliorated cell death following pilocarpine-induced seizures in infant rats. MMP-9 knockout mice were less susceptible to seizure-induced brain injury. Transgenic rats overexpressing MMP-9 were equally susceptible to seizure-induced brain injury as wild type rats. Our results suggest a significant contribution of MMP-9 to cell death after pilocarpine-induced seizures in the developing brain. As indicated by Western blot analysis, MMP-9 activation may be linked to activation of the Erk/CREB-pathway. The findings implicate involvement of MMP-9 in the pathophysiology of brain injury following seizures in the developing brain. (c) 2012 Elsevier Inc. All rights reserved.