Nrf2 Signaling in Sodium Azide-Treated Oligodendrocytes Restores Mitochondrial Functions

AbstractMitochondrial dysfunctions mark a critical step in many central nervous system (CNS) pathologies, including multiple sclerosis (MS). Such dysfunctions lead to depolarization of mitochondrial membranes and imbalanced redox homeostasis. In this context, reactive oxygen species (ROS) are potentially deleterious but can also act as an important signaling step for cellular maintenance. The transcription factor nuclear  factor (erythroid-derived 2)-like 2 (Nrf2), the key regulator in the cellular oxidative stress-response, induces a battery of genes involved in repair and regeneration. Here, we investigated the relevance of Nrf2 signaling for the prevention of cellular damage caused by dysfunctional mitochondria . We employed sodium azide (SA) as mitochondrial inhibitor on oligodendroglial OliNeu cells in vitro, and the cuprizone model with wild type and GFAP-Cre+::Keap1loxP/loxP mice to induce mitochondrial defects. The importance of Nrf2 for cellular functions and survival after SA treatment was elucidated by in vitro knockdown experiments with shRNA directed against Nrf2 and its inhibitor Keap1 as well as by methysticin treatment. Metabolic activity, cytotoxicity, and depolarization of the mitochondrial membrane were analyzed after SA treatment. The expression of Nrf2 target genes as well as endoplasmic reticulum stress response genes was additionally measured by real-time PCR (in vitro) and PCR gene arrays (in vivo). Treatment of OliNeu cells with SA resulted in signi...
Source: Journal of Molecular Neuroscience - Category: Neuroscience Source Type: research