Cyclosporine A Treatment Abrogates Ischemia‐Induced Neuronal Cell Death by Preserving Mitochondrial Integrity through Upregulation of the Parkinson's Disease‐Associated Protein DJ‐1

摘要

Summary Aims Hypoxic-ischemia alters mitochondrial membrane potential (Δ ψ m), respiratory-related enzymes, and mitochondrial DNA (mtDNA). Drugs acting on mitochondria, such as cyclosporine A (CsA), may reveal novel mitochondria-based cell death signaling targets for stroke. Our previous studies showed that Parkinson's disease-associated protein DJ-1 participates in the acute endogenous neuroprotection after stroke via mitochondrial pathway. DJ-1 was detected immediately after stroke and efficiently translocated into the mitochondria offering a new venue for developing treatment strategies against stroke. Here, we examined a molecular interaction between CsA and mitochondrial integrity in the in vitro acute stroke model of oxygen glucose deprivation/reperfusion (OGD/R) injury with emphasis on DJ-1. Methods Primary rat neuronal cells (PRNCs) were exposed to OGD/R injury and processed for immunocytochemistry, ELISA, and mitochondria-based molecular assays to reveal the role of DJ-1 in CsA modulation of mitochondrial integrity. Results Administration of CsA before stroke onset (24 h pre-OGD/R) afforded significantly much more robust neuroprotective effects than when CsA was initiated after stroke (2 h post-OGD/R), revealing that CsA exerted neuroprotection in the early phase of ischemic stroke. CsA prevented the mitochondria-dependent cell death signaling pathway involved in cytochrome c (Cyt c )-induced intrinsic apoptotic process. CsA preserved cellular ATP content, but not hexokinase activity under hypoxic conditions. CsA prevented both mtDNA decrement and Δ ψ m degradation after reperfusion, and enhanced secretion of DJ-1 in the mitochondria, coupled with reduced oxidative stress. Conclusion These observations provided evidence that CsA maintained mitochondrial integrity likely via DJ-1 upregulation, supporting the concept that mitochondria-based treatments targeting the early phase of disease progression may prove beneficial in stroke.