Sex-specific regulation of angiogenin in Alzheimer's disease.

Alzheimer's disease (AD) is a heterogeneous neurodegenerative disorder, highlighting the need to identify novel molecular regulators for effective treatment development. Angiogenin (ANG), a stress-responsive ribonuclease that inhibits apoptosis by generating 5'-tRNA fragments, is a candidate whose expression and regulation in AD is not understood. Here, we investigated ANG expression and regulation using AD cell and animal models, postmortem human brain tissue, and transcriptomic datasets (n = 645). We found that ANG is dysregulated in AD in a sex-dependent manner, altering downstream levels of 5'-tiRNAGly-GCC. Our analysis revealed female-specific molecular subtypes, absent in males: Subtype 1 featured low ANG levels with increased inflammation and neuronal death; subtype 2 exhibited higher ANG expression and intermediate pathology; subtype 3, marked by the highest ANG levels, showed reduced inflammation, slower cognitive decline, and extended survival. These findings position ANG as a key modulator of neuroinflammation and apoptosis in AD, highlighting its potential as a treatment strategy.