iPSCNPC transplantation alleviates brain injury after intracerebral hemorrhage in mice by downregulating autophagy via AMPK/ mTOR signaling pathway.

BACKGROUND AND PURPOSE: Intracerebral hemorrhage (ICH) is a devastating acute neurological condition with high mortality and disability. Induced pluripotent stem cell-derived neural progenitor cells (iPSCNPCs) have been shown to promote behavioral recovery by enhancing neural connectivity and providing trophic support. As the adenosine monophosphate-activated protein kinase (AMPK)/ mammalian target of rapamycin (mTOR) signaling pathway is a key regulator of autophagy in stroke, we investigated its role in the context of iPSCNPC transplantation for ICH.

MATERIALS AND METHODS: The therapeutic effects of iPSCNPC transplantation were evaluated in both in vivo and in vitro ICH models. We analyzed changes in the protein and mRNA expression, along with immunofluorescence, of key markers including glial fibrillary acidic protein (GFAP), AMPK, mTOR, sequestosome 1 (SQSTM1/ P62), and microtubule-associated protein 1 light chain 3 (LC3).

RESULTS: Our findings demonstrate that iPSCNPCs secrete cytokines that mitigate brain injury and protect astrocytes from autophagy. Specifically, iPSCNPCs promoted astrocyte activation by inhibiting AMPK phosphorylation and promoting mTOR activation in both model systems. The anti-autophagic effect of iPSCNPCs on astrocytes was abolished by an mTOR inhibitor. Conversely, AMPK knockdown with siRNA promoted mTOR phosphorylation and suppressed autophagy in astrocytes.

CONCLUSION: This study identifies the interaction between AMPK and mTOR in astrocytes as a critical mechanism underlying the therapeutic benefits of iPSC-NPC transplantation, highlighting it as a promising target for ICH treatment.