Quieting the Storm: Hypoxia as a Strategy to Boost UC-MSC Therapies for Neonatal Hypoxic-Ischemic Encephalopathy

Integrating stem cell therapies into clinical settings faces several challenges, particularly in achieving the high cell yields necessary for attaining therapeutic doses. Preconditioning with hypoxic conditions has shown promise in enhancing the UC-MSCs reparative capabilities of the central nervous system. Recent evidence suggests that oxygen concentration and exposure duration can shape MSCs phenotypes, supporting the need for further optimization of this strategy in a way to achieve maximal repair. In this study, we assessed the effects of both prolonged mild hypoxia (MH; 5% oxygen for 48 hours) and short severe hypoxia (SSH; 0.1% oxygen for 24 hours) on UC-MSCs ability to alleviate motor and cognitive deficits in a rodent model of neonatal HIE. Our results show that short, severe hypoxia led to more improvements in functional recovery than prolonged mild hypoxia, supporting that specific preconditioning parameters are crucial in maximizing UC-MSC therapeutic potential. To investigate the molecular effects of hypoxia-preconditioned MSCs in the neonatal brain post-HIE, we employed untargeted proteomics on ipsilesional brain samples from control, HIE, HIE treated with naive UC-MSCs, and HIE treated with SSH-preconditioned UC-MSCs groups, 30 days after lesion induction. This approach identified protein signatures related to injury and therapeutic intervention. Pathway enrichment analysis further revealed that administration of UC-MSCs preconditioned with short severe hypoxia significantly impacted neural signaling, protein synthesis, and energy metabolism pathways, pointing to long-term mechanisms that may support neuronal repair. These findings enhance our understanding of hypoxia-preconditioning in MSCs therapy in driving a positive therapeutic response, supporting the development of more effective and feasible treatments for neonatal HIE.