Nerve growth factor protects against 6-hydroxydopamine-induced oxidative stress by increasing expression of heme oxygenase-1 in a phosphatidylinositol 3-kinase-dependent manner
Nerve growth factor protects against 6-hydroxydopamine-induced oxidative stress by increasing expression of heme oxygenase-1 in a phosphatidylinositol 3-kinase-dependent manner
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DOI：
10.1074/jbc.m209164200
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发表时间：
2003-04-18
影响因子：
4.8
通讯作者：
Cuadrado, A
中科院分区：
文献类型：
--
作者：
Salinas, M;Diaz, R;Cuadrado, A
磷脂酰肌醇3 - 激酶（PI3K）/Akt1通路所引发的存活信号与促凋亡蛋白的失活以及活性氧（ROS）在一般应激诱导下增加的减弱相关。然而，该通路调节细胞内ROS水平的机制在很大程度上仍未被探究。在本研究中，我们证明神经生长因子（NGF）通过一种涉及PI3K/Akt依赖性诱导应激反应蛋白血红素加氧酶 - 1（HO - 1）的机制，阻止帕金森病相关神经毒素6 - 羟多巴胺（6 - OHDA）刺激的多巴胺能PC12细胞中ROS的积累。用氯化钴（CoCl₂）诱导HO - 1表达、用胆红素（一种血红素分解代谢的终产物）处理以及用人HO - 1逆转录病毒表达载体感染，均可模拟NGF的作用。HO - 1在NGF诱导的ROS减少中的相关性进一步通过以下证据得到证明：用HO - 1抑制剂锡原卟啉处理或用反义HO - 1逆转录病毒表达载体感染的细胞，尽管存在神经营养因子，但在对6 - OHDA的反应中表现出ROS释放增加。抑制PI3K可阻止NGF对HO - 1 mRNA和蛋白的诱导，并部分逆转其对6 - OHDA诱导的ROS释放的保护作用。相比之下，用膜靶向的活性Akt1转染的细胞，即使在没有NGF的情况下，也表现出HO - 1表达增加，并且在对6 - OHDA的反应中ROS产生和细胞凋亡大大减少。这些观察结果表明，PI3K/Akt通路通过调节抗氧化酶HO - 1的表达来控制细胞内ROS的水平。
The survival signal elicited by the phosphatidylinositol 3-kinase (PI3K)/Akt1 pathway has been correlated with inactivation of pro-apoptotic proteins and attenuation of the general stress-induced increase in reactive oxygen species (ROS). However, the mechanisms by which this pathway regulates intracellular ROS levels remain largely unexplored. In this study, we demonstrate that nerve growth factor (NGF) prevents the accumulation of ROS in dopaminergic PC12 cells challenged with the Parkinson's disease-related neurotoxin 6-hydroxydopamine (6-OHDA) by a mechanism that involves PI3K/Akt-dependent induction of the stress response protein heme oxygenase-1 (HO-1). The effect of NGF was mimicked by induction of HO-1 expression with CoCl2,; by treatment with bilirubin, an end product of heme catabolism; and by infection with a retroviral expression vector for human HO-1. The relevance of HO-1 in NGF-induced ROS reduction was further demonstrated by the evidence that cells treated with the HO-1 inhibitor tin-protoporphyrin or infected with a retroviral expression vector for antisense HO-1 exhibited enhanced ROS release in response to 6-OHDA, despite the presence of the neurotrophin. Inhibition of PI3K prevented NGF induction of HO-1 mRNA and protein and partially reversed its protective effect against 6-OHDA-induced ROS release. By contrast, cells transfected with a membrane-targeted active version of Akt1 exhibited increased HO-1 expression, even in the absence of NGF, and displayed a greatly attenuated production of ROS and apoptosis in response to 6-OHDA. These observations indicate that the PI3K/Akt pathway controls the intracellular levels of ROS by regulating the expression of the antioxidant enzyme HO-1.