Protein kinase D1 (PKD1) activation mediates a compensatory protective response during early stages of oxidative stress-induced neuronal degeneration.
Protein kinase D1 (PKD1) activation mediates a compensatory protective response during early stages of oxidative stress-induced neuronal degeneration.
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DOI：
10.1186/1750-1326-6-43
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发表时间：
2011-06-22
影响因子：
15.1
通讯作者：
Kanthasamy AG
中科院分区：
文献类型：
--
作者：
Asaithambi A;Kanthasamy A;Saminathan H;Anantharam V;Kanthasamy AG
氧化应激是导致许多神经退行性疾病中退行性过程的关键病理生理机制，因此，阐明氧化性神经元损伤各个阶段的分子机制对于更好地理解疾病和开发新的治疗模式至关重要。我们先前表明，蛋白激酶C δ（PKCδ）蛋白水解激活在氧化应激的晚期阶段是一个关键的促凋亡信号机制，有助于帕金森病（PD）模型中的氧化损伤。时程研究表明，PKCδ激活先于凋亡细胞死亡，细胞抵抗早期氧化损伤，表明一些内在的代偿反应保护神经元免受早期氧化损伤。因此，本研究的目的是在氧化应激的早期阶段，多巴胺能神经元的保护信号通路的特点。在此，我们确定蛋白激酶D1（PKD 1）作为一个关键的抗凋亡激酶，以保护神经细胞免受早期阶段的氧化应激。多巴胺能神经元细胞暴露于H2 O2或6-OHDA诱导PKD 1激活环（PKD 1 S744/748）磷酸化，早在诱导神经元细胞死亡之前。阻断PKCδ裂解、PKCδ敲低或过表达抗裂解PKCδ突变体可有效减弱PKD 1活化，表明PKCδ蛋白水解活化调节PKD 1磷酸化。此外，PKCδ催化片段，而不是调节片段，增加PKD 1的活化，证实PKCδ活性调节PKD 1的活化。我们还发现，在C-末端的S916磷酸化是PKD 1激活环磷酸化所需的前一个事件。重要的是，通过RNAi敲低或过表达PKD 1 S916 A磷酸缺陷突变体对PKD 1的负调节增强了氧化应激诱导的细胞凋亡，而通过过表达全长PKD 1或组成型活性PKD 1质粒对PKD 1的正调节减弱了氧化应激诱导的细胞凋亡，表明PKD 1在氧化神经元损伤期间具有抗细胞凋亡作用。总的来说，我们的研究结果表明，PKCδ依赖性激活PKD 1代表了一种新的内在保护反应，在抵消早期阶段的氧化损伤的神经元细胞。我们的研究结果表明，PKD 1介导的多巴胺能神经元的氧化损伤的代偿性保护机制的积极调制可能提供新的神经保护策略治疗PD。
Oxidative stress is a key pathophysiological mechanism contributing to degenerative processes in many neurodegenerative diseases and therefore, unraveling molecular mechanisms underlying various stages of oxidative neuronal damage is critical to better understanding the diseases and developing new treatment modalities. We previously showed that protein kinase C delta (PKCδ) proteolytic activation during the late stages of oxidative stress is a key proapoptotic signaling mechanism that contributes to oxidative damage in Parkinson's disease (PD) models. The time course studies revealed that PKCδ activation precedes apoptotic cell death and that cells resisted early insults of oxidative damage, suggesting that some intrinsic compensatory response protects neurons from early oxidative insult. Therefore, the purpose of the present study was to characterize protective signaling pathways in dopaminergic neurons during early stages of oxidative stress. Herein, we identify that protein kinase D1 (PKD1) functions as a key anti-apoptotic kinase to protect neuronal cells against early stages of oxidative stress. Exposure of dopaminergic neuronal cells to H2O2 or 6-OHDA induced PKD1 activation loop (PKD1S744/748) phosphorylation long before induction of neuronal cell death. Blockade of PKCδ cleavage, PKCδ knockdown or overexpression of a cleavage-resistant PKCδ mutant effectively attenuated PKD1 activation, indicating that PKCδ proteolytic activation regulates PKD1 phosphorylation. Furthermore, the PKCδ catalytic fragment, but not the regulatory fragment, increased PKD1 activation, confirming PKCδ activity modulates PKD1 activation. We also identified that phosphorylation of S916 at the C-terminal is a preceding event required for PKD1 activation loop phosphorylation. Importantly, negative modulation of PKD1 by the RNAi knockdown or overexpression of PKD1S916A phospho-defective mutants augmented oxidative stress-induced apoptosis, while positive modulation of PKD1 by the overexpression of full length PKD1 or constitutively active PKD1 plasmids attenuated oxidative stress-induced apoptosis, suggesting an anti-apoptotic role for PKD1 during oxidative neuronal injury. Collectively, our results demonstrate that PKCδ-dependent activation of PKD1 represents a novel intrinsic protective response in counteracting early stage oxidative damage in neuronal cells. Our results suggest that positive modulation of the PKD1-mediated compensatory protective mechanism against oxidative damage in dopaminergic neurons may provide novel neuroprotective strategies for treatment of PD.
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DOI：
10.1523/jneurosci.1879-08.2008
发表时间：
2008-09-10
期刊：
The Journal of neuroscience : the official journal of the Society for Neuroscience
影响因子：
--
作者：
Bisbal M;Conde C;Donoso M;Bollati F;Sesma J;Quiroga S;Díaz Añel A;Malhotra V;Marzolo MP;Cáceres A
通讯作者：
Cáceres A
影响因子：
4.8
作者：
Celil, AB;Campbell, PG
通讯作者：
Campbell, PG
影响因子：
4.8
作者：
Iglesias, T;Rozengurt, E
通讯作者：
Rozengurt, E
影响因子：
3.4
作者：
Kitazawa, M;Anantharam, V;Kanthasamy, AG
通讯作者：
Kanthasamy, AG
影响因子：
3.3
作者：
Kitazawa, M;Anantharam, V;Kanthasamy, AG
通讯作者：
Kanthasamy, AG