One of the most important mechanisms of preconditioning-mediated neuroprotection is the attenuation of cell apoptosis, inducing brain tolerance after a subsequent injurious ischemia. In this context, the antiapoptotic PI3K/AKT signaling pathway plays a key role by regulating cell differentiation and survival. Active AKT is known to increase the expression of murine double minute-2 (MDM2), an E3-ubiquitin ligase that destabilizes p53 to promote the survival of cancer cells. In neurons, we recently showed that the MDM2–p53 interaction is potentiated by pharmacological preconditioning, based on subtoxic stimulation of NMDA glutamate receptor, which prevents ischemia-induced neuronal apoptosis. However, whether this mechanism contributes to the neuronal tolerance during ischemic preconditioning (IPC) is unknown. Here, we show that IPC induced PI3K-mediated phosphorylation of AKT at Ser⁴⁷³, which in turn phosphorylated MDM2 at Ser¹⁶⁶. This phosphorylation triggered the nuclear stabilization of MDM2, leading to p53 destabilization, thus preventing neuronal apoptosis upon an ischemic insult. Inhibition of the PI3K/AKT pathway with wortmannin or by AKT silencing induced the accumulation of cytosolic MDM2, abrogating IPC-induced neuroprotection. Thus, IPC enhances the activation of PI3K/AKT signaling pathway and promotes neuronal tolerance by controlling the MDM2–p53 interaction. Our findings provide a new mechanistic pathway involved in IPC-induced neuroprotection via modulation of AKT signaling, suggesting that AKT is a potential therapeutic target against ischemic injury.

Reactive oxygen species (ROS), particularly superoxide anion (O₂^•-) and hydrogen peroxide (H₂O₂), originating from mitochondria, are increasingly recognized as critical mediators of physiological signaling and cellular function. While in the adult brain, mitochondrial ROS, specifically mitochondrial H₂O₂, modulate metabolism and sustains cognitive processes, their role in the developing cerebral cortex remains undefined. Here, we leverage a knock-in mouse model constitutively expressing mitochondrially targeted catalase (mCAT) to attenuate mitochondrial H₂O₂ levels and investigate their impact during cortical development. In neurosphere cultures derived from embryonic day 14.5 (E14.5) mCAT mice, reduced mitochondrial H₂O₂ altered glutathione redox homeostasis and glucose metabolism leading to suppressed progenitor cell proliferation, without compromising viability. In vivo, neural progenitor cell (NPC) proliferation, neuronal differentiation and cortical layering were disrupted starting at gestational day E15. Together, these data uncover a physiological role for mitochondrial hydrogen peroxide in orchestrating neural precursor proliferation and differentiation, ultimately influencing mammalian cerebral cortex formation.

Glycolysis is primarily involved in ATP production but also modulates oxidative stress. Chronic alcohol consumption is correlated with an increased incidence of multiple diseases, including cancer and neurodegenerative diseases (NDDs), though the underlying mechanisms remain unclear. Guided by a literature review and bioinformatics analysis, we evaluated the expression of 22 genes encoding various isoforms of seven glycolytic enzymes (GEs) in the peripheral blood of patients with alcohol use disorder (AUD), individuals with acute alcohol consumption (AAC), and their respective control groups using qPCR. In parallel, we evaluated the expression of selected genes coding for GEs linked to NDDs, as well as astrocytic markers in primary mouse astrocyte cultures exposed to ethanol. Thirteen GE-related genes, including non-canonical isoforms, were significantly dysregulated in AUD patients; notably, eight of these genes showed similar alterations in individuals with AAC. Several enzymes encoded by these genes are known to be regulated by oxidative stress. Ethanol-exposed astrocytes also showed altered expression of glycolytic genes associated with NDDs and astrocyte function. These findings indicate that glycolytic dysregulation is driven by ethanol intake, regardless of exposure duration or organic damage, highlighting a link between ethanol-driven redox imbalance and glycolytic remodeling, which could contribute to organ damage.

Non-traumatic intracerebral hemorrhage (ICH) is one of the most devastating and disabling forms of stroke; however, there are no effective pharmacological therapies available following the insult. Angiogenesis appears as a key step to overcoming the damage and promoting functional recovery. In this context, endothelial progenitor cells (EPCs) mobilization improves oxidative stress and promotes neovascularization, which has been linked to beneficial outcomes following both ischemic and hemorrhagic stroke. The TNF-like weak inducer of apoptosis (TWEAK), binding to its receptor Fn14, has been suggested as an inducer of EPCs differentiation, viability and migration to the injury site in a model of myocardial infarction. Here, we have performed a proof-of-concept preclinical study in a rat model of ICH where we report that a 50 μg/kg dose of rat recombinant TWEAK (rTWEAK) promotes blood progenitor cells mobilization, mainly EPCs. As soon as 72 h post-injury, brain neovascularization, and, importantly, long-term hematoma reduction and improved functional recovery is reported. In contrast, a higher dose of 150 μg/kg blocked those beneficial outcomes. Therefore, a low dose of rTWEAK treatment promotes neovascularization and reduces brain damage in a rat model of ICH. Further clinical studies will be needed to demonstrate if rTWEAK could represent a new strategy to promote recovery following ICH.