Knockdown of PKM2 Promotes Proliferation and Neuronal Differentiation of Neural Stem Cells by Inhibiting PINK1/Parkin-Mediated Excessive Mitophagy

Neural stem cells (NSCs) are essential for replenishing nerve cells, providing neuroprotection, and repairing damaged brain function, while mitophagy is critical for maintaining NSCs’ homeostasis. The study investigated whether pyruvate kinase M2 (PKM2) regulates NSCs’ proliferation and differentiation by modulating mitophagy.

This study established a model of excessive autophagy in neural stem cell mitochondria induced by cobalt chloride (CoCl₂) and used plasmid transfection technology to knock down PKM2 expression, examining its effects on NSCs proliferation and differentiation. Additionally, potential mechanisms were explored by overexpressing phosphatase and tensin homolog-induced putative kinase 1 (PINK1) and adding the mitophagy inducer carbonyl cyanide m-chlorophenyl hydrazone (CCCP).

Treatment with CoCl₂ significantly inhibited the proliferation of NSCs and their differentiation into neurons, induced excessive mitophagy, and activated the PKM2/PINK1/Parkin pathway. Knockdown of PKM2 markedly enhanced cell viability, promoted NSCs’ proliferation, and neuronal differentiation. Mechanistically, PKM2 knockdown not only decreased the protein levels of PINK1, Parkin, p-Parkin, Beclin1, and LC3 II/I but also increased p62 expression, thereby mitigating excessive mitophagy. Overexpression of PINK1 attenuated the inhibitory effect of PKM2 knockdown on CoCl₂-induced mitophagy in NSCs. Moreover, PKM2 knockdown significantly reversed the detrimental effects of CCCP on mitochondrial function, cell survival, and neuronal differentiation, further confirming that PKM2 promotes NSC proliferation and neuronal differentiation by inhibiting mitophagy.

Knocking down PKM2 could inhibit PINK1/Parkin-mediated excessive mitophagy, thereby promoting NSCs proliferation and neuronal differentiation.