Annexin A1 inhibits neuronal apoptosis in amyotrophic lateral sclerosis by restraining the Hippo pathway.

Annexin A1 (ANXA1) is a multifunctional regulatory protein involved in neuroinflammation and cellular homeostasis, but its role in amyotrophic lateral sclerosis (ALS) remains unclear. In this study, we investigated the relationship between ANXA1 and Hippo pathway signaling in ALS. Bioinformatic analysis of transcriptomic data from iPSC-derived motor neurons showed that ANXA1 expression was reduced in ALS and associated with apoptosis and Hippo pathway-related changes. Decreased ANXA1 expression was confirmed in hSOD1^G93A transgenic mice and NSC34 motor neuron-like cells. Phosphorylation levels of MST1/2, LATS1/2, and YAP1 were elevated, indicates activation of the Hippo pathway. Functional experiments showed that ANXA1 overexpression reduced Hippo pathway activation, enhanced cell viability, and decreased apoptosis, as increased Bcl-2 expression and reduced Bax and cleaved caspase-9 levels. In contrast, ANXA1 knockdown further activated Hippo pathway and aggravated apoptotic changes. These findings identify ANXA1 as an upstream regulator associated with Hippo pathway activation in ALS and suggest that the ANXA1/Hippo axis may represent a potential therapeutic target.