Mitochondrial mechanism of neuroprotection by CART
Mitochondrial mechanism of neuroprotection by CART
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DOI：
10.1111/j.1460-9568.2007.05691.x
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发表时间：
2007-08-01
影响因子：
3.4
通讯作者：
Alkayed, Nabil J.
中科院分区：
文献类型：
--
作者：
Mao, Peizhong;Ardeshiri, Ardi;Alkayed, Nabil J.
我们以前证明，神经肽可卡因和安非他明调节的转录（CART）是保护局灶性脑缺血在体内和对神经元细胞死亡的培养诱导的氧-葡萄糖剥夺（OGD）。CART的神经保护机制尚不清楚，部分原因是缺乏对其假定受体的了解。利用酵母双杂交系统筛选小鼠脑cDNA文库，发现CART与线粒体琥珀酸脱氢酶（SDHB）亚基B之间存在直接相互作用。我们使用体外pull-down测定证实了CART/SDHB结合，并测试了CART肽对基础条件下和OGD后原代培养的皮层神经元中SDH活性、复合物II（CII）活性和ATP产生的影响。在0.2和4 nM之间的浓度下，CART显著增加了基线条件下纯化线粒体和完整神经元中的SDH功能、CII活性和ATP生成。此外，CART预处理增强了神经元存活的线粒体机制，并防止了OGD后SDH和CII活性以及ATP产生的下降。研究结果表明，CART的神经保护作用机制可能与缺血再灌注损伤后线粒体功能的保护和能量衰竭的预防有关。
We previously demonstrated that the neuropeptide cocaine- and amphetamine-regulated transcript (CART) is protective against focal cerebral ischemia in vivo and against neuronal cell death in culture induced by oxygen-glucose deprivation (OGD). The mechanism of neuroprotection by CART is unknown, in part due to lack of knowledge regarding its putative receptor. Using a yeast two-hybrid system with CART's carboxy-terminal to screen a mouse brain cDNA library, we uncovered a potential direct interaction between CART and subunit B of the mitochondrial enzyme succinate dehydrogenase (SDHB). We confirmed CART/SDHB binding using in vitro pull-down assay, and tested the effects of CART peptide on SDH activity, Complex II (CII) activity and ATP production in primary cultured cortical neurons under basal conditions and after OGD. At concentrations between 0.2 and 4 nM, CART significantly increased SDH function, CII activity and ATP generation in purified mitochondria and intact neurons under baseline conditions. Furthermore, pretreatment with CART enhanced mitochondrial mechanisms of neuronal survival and prevented the decline in SDH and CII activities and ATP production after OGD. The findings suggest that CART's neuroprotective mechanism of action may be linked to preservation of mitochondrial function and prevention of energy failure after ischemia-reperfusion injury.