Nrf2 Regulates Oxidative Stress and Its Role in Cerebral Ischemic StrokeCerebral ischemic stroke is characterized by acute ischemia in a certain part of the brain, which leads to brain cells necrosis, apoptosis, ferroptosis, pyroptosis, etc. At present, there are limited effective clinical treatments for cerebral ischemic stroke, and the recovery of cerebral blood circulation will lead to cerebral ischemia-reperfusion injury (CIRI). Cerebral ischemic stroke involves many pathological processes such as oxidative stress, inflammation, and mitochondrial dysfunction. Nuclear factor erythroid 2-related factor 2 (Nrf2), as one of the most critical antioxidant transcription factors in cells, can coordinate various cytoprotective factors to inhibit oxidative stress. Targeting Nrf2 is considered as a potential strategy to prevent and treat cerebral ischemia injury. During cerebral ischemia, Nrf2 participates in signaling pathways such as Keap1, PI3K/AKT, MAPK, NF-κB, and HO-1, and then alleviates cerebral ischemia injury or CIRI by inhibiting oxidative stress, anti-inflammation, maintaining mitochondrial homeostasis, protecting the blood-brain barrier, and inhibiting ferroptosis. In this review, we have discussed the structure of Nrf2, the mechanisms of Nrf2 in cerebral ischemic stroke, the related research on the treatment of cerebral ischemia through the Nrf2 signaling pathway in recent years, and expounded the important role and future potential of the Nrf2 pathway in cerebral ischemic stroke.
Arsenic Induces Insulin Resistance in Mouse Adipocytes and Myotubes Via Oxidative Stress-Regulated Mitochondrial Sirt3-FOXO3a Signaling PathwayChronic exposure to arsenic via drinking water is associated with an increased risk for development of type 2 diabetes mellitus (T2DM). This study investigates the role of mitochondrial oxidative stress protein Sirtuin 3 (Sirt3) and its targeting proteins in chronic arsenic-induced T2DM in mouse adipocytes and myotubes. The results show that chronic arsenic exposure significantly decreased insulin-stimulated glucose uptake (ISGU) in correlation with reduced expression of insulin-regulated glucose transporter type 4 (Glut4). Expression of Sirt3, a mitochondrial deacetylase, was dramatically decreased along with its associated transcription factor, forkhead box O3 (FOXO3a) upon arsenic exposure. A decrease in mitochondrial membrane potential (Δψm) was observed in both 3T3L1 adipocytes and C2C12 myotubes treated by arsenic. Reduced FOXO3a activity by arsenic exhibited a decreased binding affinity to the promoters of both manganese superoxide dismutase (MnSOD) and peroxisome proliferator-activated receptor-gamma coactivator (PGC)-1α, a broad and powerful regulator of reactive oxygen species (ROS) metabolism. Forced expression of Sirt3 or MnSOD in mouse myotubes elevated Δψm and restored ISGU inhibited by arsenic exposure. Our results suggest that Sirt3/FOXO3a/MnSOD signaling plays a significant role in the inhibition of ISGU induced by chronic arsenic exposure.