Transgenic animal injury paradigms

转基因动物损伤范例

基本信息

批准号：
6396017
负责人：
PAK H CHAN
金额：
$ 18.53万
依托单位：
STANFORD UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2000
资助国家：
美国
起止时间：
2000-03-01 至 2001-02-28
项目状态：
已结题

项目摘要

It is well-established that a brief period of global brain ischemia causes delayed cell death in hippocampal CA1 pyramidal neurons days after reperfusion in animals and humans. Although numerous factors have been indicated in this phenomenon, the mechanisms underlying this delayed neuronal cell death are still poorly understood. We have demonstrated that cerebral infarction and neurological deficits are significantly reduced in transgenic mice over-expressing CuZn-superoxide dismutase (Sod1) activity after acute focal stroke, whereas vasogenic edema, infarction and neurological deficits are exacerbated in mutant mice deficient in SOD1 or in mitochondrial manganese SOD (Sod2) activities. But the role of these antioxidant enzymes on the delayed hippocampal neuronal injury after global ischemia is still unknown. Our hypothesis is that oxidative stress induced by mild ischemia and reperfusion causes the delayed hippocampal neuronal injury and death through pathways involving both necrosis and apoptosis, and that the latter is exacerbated when mitochondrial dysfunction occurs during reperfusion. It is our aim to test our hypothesis using transgenic mice over-expressing Sod1 and Sod2 activities and knockout mutant mice that contain no SOD1 -/- (homozygous), half (heterozygous, Sod1 +/-) or SOD2 +/- activities. In order to dissect out the role of mitochondrial dysfunction in ischemic brain injury, we will study the cytosolic distribution of mitochondrial dysfunction in ischemic brain injury, we will study the cytosolic distribution of mitochondrial proteins cytochrome c and cytochrome c oxidase in ischemic brain tissue. Cytochrome c release from mitochondria has been attributed to the activation of caspase 3 and subsequent apoptosis in cells following exogenous apoptotic stimuli. In order to elucidate the oxidative role of subcellular compartmentation (i.e., cytosolic versus mitochondria) in necrosis and apoptosis, we will generate mice that contain genotypes with combinations of increased Sod1 expression and Sod2 +/- knockout mutants. We will investigate whether increased cytosolic CuZnSOD (SOD1) activity will reduce neuronal apoptosis in Sod2 +/- knockout mice that are vulnerable to transient forebrain ischemia. We believe these are unique and fresh approaches that will provide insights into the oxidative mechanism in mitochondria that underlies apoptosis in delayed hippocampal cell death after global cerebral ischemia and reperfusion.

良好的确立的是，短暂的全球脑缺血会导致动物和人类再灌注几天后海马CA1锥体神经元延迟细胞死亡。尽管在这种现象中已经表明了许多因素，但这种延迟神经元细胞死亡的机制仍然很少了解。 We have demonstrated that cerebral infarction and neurological deficits are significantly reduced in transgenic mice over-expressing CuZn-superoxide dismutase (Sod1) activity after acute focal stroke, whereas vasogenic edema, infarction and neurological deficits are exacerbated in mutant mice deficient in SOD1 or in mitochondrial manganese SOD (Sod2) activities.但是，这些抗氧化剂酶在全球缺血后延迟的海马神经元损伤中的作用仍然未知。我们的假设是，由轻度缺血引起的氧化应激并再灌注会导致海马神经元损伤延迟，并通过涉及坏死和凋亡的途径延迟，而在再灌注过程中线粒体功能障碍发生时，后者会加剧。我们的目的是使用过表达的SOD1和SOD2活性的转基因小鼠和敲除突变小鼠进行测试，该突变小鼠不含SOD1 - / - （纯合子），一半（杂合，SOD1 +/-）或SOD2 +/-活动。为了剖析线粒体功能障碍在缺血性脑损伤中的作用，我们将研究线粒体功能障碍在缺血性脑损伤中的胞质分布，我们将研究线粒体蛋白细胞色素c和细胞色素蛋白蛋白蛋白质蛋白质C和细胞色素蛋白酶氧化酶在异性脑组织中的细胞质分布。线粒体从线粒体释放的细胞色素C归因于胱天蛋白酶3的激活以及外源性凋亡刺激后细胞中随后的细胞凋亡。为了阐明在坏死和凋亡中亚细胞隔室（即胞质与线粒体）的氧化作用，我们将生成包含基因型的小鼠，这些小鼠含有具有增加SOD1表达和SOD2 +/-敲除突变体的组合的基因型。我们将研究增加的胞质CuznSOD（SOD1）活性是否会减少容易受到短暂前脑缺血的SOD2 +/-敲除小鼠的神经元凋亡。我们认为，这些是独特而新鲜的方法，它将提供有关线粒体中氧化机制的见解，在整体脑缺血和再灌注后，海马细胞死亡延迟的海马细胞死亡中凋亡是基础的。