Inhibition of METTL14 Alleviates OGD/R-Induced Neuronal Differentiation Injury in Neural Stem Cells Through Suppressing the Tp53inp2/Ptgs2 Axis: Potential Benefits for the Mouse MCAO Model.

BACKGROUND

Ischemic stroke (IS) is an acute cerebrovascular disease characterized by high morbidity and mortality, with limited current treatment options. Tumor protein p53-inducible nuclear protein 2 (Tp53inp2) is known to be a positive regulator of autophagy under physiological conditions, but the mechanism of Tp53inp2 in IS remains unclear. In this study, we aimed to explore the mechanism of Tp53inp2 in IS.

METHODS

Primary neural stem cells (NSCs) were extracted and identified. An OGD/R cell model was constructed. Tp53inp2 was knocked down and rapamycin was added. A middle cerebral artery occlusion (MCAO) animal model was constructed, and then 5 μL of 5 × 105 NSCs, either untreated or transfected with sh-NC or sh-Tp53inp2, were injected. Additionally, at the cellular level, Ptgs2 or Tp53inp2 was overexpressed, and METTL14 was knocked down.

RESULTS

Inhibition of Tp53inp2 mitigated OGD/R-induced mitophagy and ROS levels in vitro. Moreover, inhibition of Tp53inp2 mediated neuronal differentiation of OGD/R treated NSCs by suppressing mitophagy. At the animal level, the transplantation of NSCs with a knockdown of Tp53inp2 increased neuronal differentiation, thereby alleviating the effects of MCAO and mitigating cognitive impairments in MCAO model mice. Ptgs2 was further screened and validated as a downstream target mediating the effect of Tp53inp2 on NSCs. At the cellular level, Tp53inp2 alleviated OGD/R-induced mitophagy and ROS levels by regulating Ptgs2 expression. METTL14 could regulate Tp53inp2 expression by modulating the functional m6A modification sites on Tp53inp2 mRNA. Inhibition of METTL14 alleviated OGD/R-induced mitophagy and the rise of ROS levels in NSCs by inhibiting the Tp53inp2/Ptgs2 axis.

CONCLUSIONS

Inhibition of METTL14 alleviated OGD/R-induced neuronal differentiation injury in NSCs by inhibiting the Tp53inp2/Ptgs2 axis. By elucidating the mechanisms involving Tp53inp2, Ptgs2, and METTL14, this research offers a foundation for developing new strategies to enhance neuronal differentiation and mitigate cognitive impairments in stroke patients.