Sex-dependent molecular landscape of Alzheimer's disease revealed by large-scale single-cell transcriptomics.

Introduction: Alzheimer's disease (AD) shows significant sex differences in prevalence and clinical manifestations, but the underlying molecular mechanisms remain unclear.

Methods: This study used a large-scale, single-cell transcriptomic atlas of the human prefrontal cortex to investigate sex-dependent molecular changes in AD. Our approach combined cell type-specific and sex-specific differential gene expression analysis, pathway enrichment, gene regulatory network construction, and cell-cell communication analysis to identify sex-dependent changes.

Results: We found significant sex-specific gene expression patterns and pathway alterations in AD. Male astrocytes showed changes in cell death pathways, with RPTOR as a key regulator, while female astrocytes had alterations in Wnt signaling and cell cycle regulation. Cell-cell communication analysis uncovered sex-specific intercellular signaling patterns, with male-specific impacts on apoptosis-related signaling and female-specific alterations in Wnt and calcium signaling.

Discussion: This study reveals sex-dependent gene expression patterns, pathway alterations, and intercellular communication changes, suggesting the need for sex-specific approaches in AD research.

Highlights: Single-cell transcriptomics reveals significant sex-specific molecular signatures in Alzheimer's disease (AD). Male astrocytes show enhanced modulation of apoptotic and cell death pathways in AD; female astrocytes exhibit distinct alterations in Wnt signaling and cell-cycle regulation. Sex-dimorphic changes in mitochondrial gene expression are observed in excitatory neurons, suggesting divergent energy metabolism profiles may contribute to AD sex differences. RPTOR is identified as a key regulator of male-specific changes in astrocytes, implicating the mechanistic target of rapamycin pathway in sex-dependent AD pathology. New cell-cell communication analyses reveal sex-specific patterns of intercellular signaling, providing insights into how cellular interactions may differentially contribute to AD pathology in males and females.