PDF(Pubmed)
Abstract：
Calcium/calmodulin-dependent serine protein kinase (CASK) is a scaffold protein and plays critical roles in neuronal synaptic formation and brain development. Previously, CASK was shown to associate with EGFR to maintain the vulval cell differentiation in C. elegans. In this study, we explored the role of CASK in CHME3 microglial cells. We found that CASK silencing protects cells from H2O2-induced cell death by attenuating PARP-1 activation, mitochondrial membrane potential loss, reactive oxygen species production, and mitochondrial fission, but it increases oxidative phosphorylation. The PARP-1 inhibitor olaparib blocks H2O2-induced cell death, suggesting the death mode of parthanatos. CASK silencing also increases AKT activation but decreases AMPK activation under H2O2 treatment. Pharmacological data further indicate that both signaling changes contribute to cell protection. Different from the canonical parthanatos pathway, we did not observe the AIF translocation from mitochondria into the nucleus, suggesting a non-canonical AIF-independent parthanatos in H2O2-treated CHME3 cells. Moreover, we found that CASK silencing upregulates the EGFR gene and protein expression and increases H2O2-induced EGFR phosphorylation in CHME3 microglia. However, EGFR activation does not contribute to cell protection caused by CASK silencing. In conclusion, CASK plays a crucial role in microglial parthanatos upon H2O2 treatment via stimulation of PARP-1 and AMPK but the inhibition of AKT. These findings suggest that CASK might be an ideal therapeutic target for CNS disorders.
摘要：
钙/钙调蛋白依赖性丝氨酸蛋白激酶（CASK）是一种支架蛋白，在神经元突触形成和大脑发育中起关键作用。以前,CASK显示与EGFR相关以维持秀丽隐杆线虫的外阴细胞分化。在这项研究中,我们探讨了CASK在CHME3小胶质细胞中的作用。我们发现CASK沉默通过减弱PARP-1激活保护细胞免受H2O2诱导的细胞死亡。线粒体膜电位损失，活性氧的产生，和线粒体裂变，但它增加了氧化磷酸化。PARP-1抑制剂奥拉帕尼阻断H2O2诱导的细胞死亡，暗示了Parthanatos的死亡方式.CASK沉默也增加AKT活化,但在H2O2处理下降低AMPK活化。药理学数据进一步表明两种信号传导变化都有助于细胞保护。不同于典型的parthanatos途径，我们没有观察到AIF从线粒体易位到细胞核，提示H2O2处理的CHME3细胞中非经典AIF独立的parthanatos。此外，我们发现CASK沉默可上调CHME3小胶质细胞中EGFR基因和蛋白的表达,并增加H2O2诱导的EGFR磷酸化.然而,EGFR激活不有助于由CASK沉默引起的细胞保护。总之,CASK通过刺激PARP-1和AMPK而抑制AKT，在H2O2治疗的小胶质细胞副中发挥关键作用。这些发现表明CASK可能是中枢神经系统疾病的理想治疗靶点。
