Neural stem cell conditioned medium alleviates Aβ25-35 damage to SH-SY5Y cells through the PCMT1/MST1 pathway

Alzheimer’s disease (AD) is a progressive neurodegenerative disease. Evidence suggests that protein isoaspartate methyltransferase 1 (PCMT1) is highly expressed in brain tissue in the substantia nigra, blue plaque, and paraventricular nucleus. In this study, we investigated the effects of neural stem cell conditioned medium on the PCMT1/MST1 pathway to alleviate damage caused by amyloid β (Aβ)(25-35) in SH-SY5Y cells. Results demonstrated that Aβ(25-35) significantly decreased cell viability in both a time and dose-dependent manner. Neural stem cell-complete medium (NSC-CPM) or NSC-CDM had an inhibitory effect on toxicity when fibrillation of Aβ(25-35) occurred, with a greater effect observed with NSC-CDM. An increase in PCMT1 expression levels was observed in the Aβ(25-35) + NSC-CDM group. sh-PCMT1 significantly reduced cell viability and inhibited the protective effects of NSC-CDM through the induction of apoptosis and increased expression of p- MST1. Overexpression of PCMT1 reversed the decrease in cell viability and apoptosis induced by Aβ(25-35). In summary, our findings suggest that NSC-CDM corrects the damage of Aβ(25-35) to cells by increasing levels of PCMT1, which in turn reduces phosphorylation of MST.