Role of DJ1 in mitochondrial biogenergetics and neuronal metabolism

摘要 Jonas，EA 家族性帕金森病（PD）蛋白DJ-1突变与线粒体缺陷有关， 早期发病的PD，但确切的机制尚不清楚。我们已经发现DJ-1和 DJ-1敲除增加线粒体解偶联并阻碍线粒体的延伸和分支。 多巴胺能神经过程解偶联与ATP合酶异常有关 效率和化学计量。ATP合成酶的变化也与线粒体的 形态学变化，包括嵴数目、线粒体长度和 线粒体生物发生新的蛋白质合成对修复和维持多巴胺能神经元至关重要 纹状体中的神经末梢和正常的多巴胺释放能力。新蛋白的激活 合成是对生长因子或神经元刺激等线索的反应，但我们 假设当ATP合酶的化学计量比 不正常与此相一致的是，我们发现患者细胞中蛋白质合成水平非常低 和在DJ-1 KO小鼠神经元中。DJ-1与ATP合酶β亚基结合， 亚基mRNA。因此，我们推测，生长和分枝减少的机制 缺乏DJ-1的多巴胺能神经元与缺乏DJ-1靶向，神经- 调节的mRNA是神经元生长、修复和多巴胺能神经元可塑性所必需的。 细胞如果我们能在空间上恢复DJ-1下游蛋白质合成的正常速率， 时间精确的方式，我们假设我们将减缓DJ-1中神经元末梢的降解， 突变的病人和保留多巴胺释放能力。与此同时，我们现在有 通过过度表达ATP合酶β亚基恢复患者细胞中的蛋白质合成速率。我们 现在计划确定我们是否可以挽救DJ-1中的低蛋白质合成率和神经元生长 KO神经元，在表达突变体DJ-1的神经元中和在DJ-1 KO动物体内。我们会这样做 通过在神经元中通过AAV（病毒）递送过表达ATP合酶β亚基。在体内，我们将 通过使DJ-1 KO小鼠与低C亚基杂交来恢复线粒体的正常偶联 泄漏KI鼠标。我们将恢复正常的ATP合成酶在体内的化学计量，通过交叉的DJ- 1只KO小鼠与过表达ATP合酶β亚基的小鼠。我们希望能保护 纹状体中的神经元末梢，并防止小鼠中功能障碍性运动的发作。 我们的观察表明，ATP合酶复合物的化学计量，蛋白质 合成速率和PD。我们的计划包括一项有前途的新战略，以开发治疗方法， PD患者。

Abstract Jonas, EA Familial Parkinson’s disease (PD) protein DJ-1 mutations are linked to mitochondrial deficits and early onset PD but the exact mechanisms are unclear. We have found that mutations in DJ-1 and DJ-1 knock out increase mitochondrial uncoupling and hamper extension and branching of dopaminergic neuronal processes. The uncoupling is associated with abnormal ATP synthase efficiency and stoichiometry. The changes in ATP synthase are also associated with mitochondrial morphological changes including changes in cristae number, mitochondrial length and mitochondrial biogenesis. New protein synthesis is crucial to repair and maintain dopaminergic endings in the striatum and for normal dopamine release capacity. The activation of new protein synthesis is in response to cues such as growth factors or neuronal stimulation, but we hypothesize that new protein synthesis fails to occur when the stoichiometry of the ATP synthase is abnormal. In keeping with this, we find that protein synthesis levels are very low in patient cells and in DJ-1 KO mouse neurons. DJ-1 is bound to ATP synthase β subunit and ATP synthase β subunit mRNA. We therefore hypothesize that the mechanism of decreased growth and branching of DJ-1 deficient dopaminergic neurons is related to a lack of DJ-1 targeted, mitochondrially- regulated, mRNAs that are required for neuronal growth, repair and plasticity of dopaminergic cells. If we can restore the normal rate of protein synthesis downstream of DJ-1 in a spatially and temporally precise manner, we hypothesize we will slow neuronal ending degradation in DJ-1 mutant patients and preserve dopamine release capability. In keeping with this, we have now restored protein synthesis rates in patient cells by overexpression of ATP synthase β subunit. We now plan to determine if we can rescue low protein synthesis rates and neuronal growth in DJ-1 KO neurons, in neurons expressing mutant DJ-1 and in vivo in DJ-1 KO animals. We will do this by overexpression of ATP synthase β subunit by AAV (viral) delivery in neurons. In vivo, we will restore the normal coupling of mitochondria by crossing the DJ-1 KO mice with a low c-subunit leak KI mouse. We will restore the normal ATP synthase stoichiometry in vivo by crossing the DJ- 1 KO mouse with a mouse overexpressing ATP synthase β subunit. We hope to preserve neuronal endings in the striatum and prevent the onset of dysfunctional movement in the mice. Our observations suggest a connection between ATP synthase complex stoichiometry, protein synthesis rates and PD. Our plan comprises a promising new strategy to develop therapies for PD patients.