Whole-body Loss of FSP27 Impairs Cognitive Function via Disruption of Neuro-Metabolic Pathways

Fat-Specific Protein 27 (FSP27), originally identified for its role in adipocyte lipid metabolism and energy homeostasis, plays a key role in regulating lipolysis and maintaining insulin sensitivity. Beyond adipose tissue, emerging studies have uncovered its involvement in hepatic and skeletal muscle function. More recently, FSP27 has also been implicated in maintaining vascular health through its influence on endothelial signaling. Despite growing insights into FSP27s systemic functions, its involvement in the central nervous system and cognitive regulation have remained unexplored. In this study, we present the first evidence that FSP27 is a critical regulator of cognitive function. Utilizing a global FSP27 knockout (Fsp27-/-) mouse model, we demonstrate that FSP27 deficiency results in significant impairments in learning, memory retention, and spatial awareness. To elucidate the underlying molecular mechanisms, genome-wide transcriptome profiling of brain tissue from Fsp27-/- mice was performed, revealing significant (P<0.05) alterations in gene expression related to neurocognition and metabolic pathways. Notably, FSP27 deletion was associated with genomic instability (P=0.05), downregulation of genes essential for axonal transport (NES=-1.91, FDR q-value=0.21), neuronal plasticity, and brain development (NES=-1.91, FDR q-value=0.28), along with signatures of disrupted systemic metabolism and elevated stress responses (NES=1.81, FDR q-value=0.20) in the brain, the processes tightly linked to cognitive dysfunction. Collectively, these findings establish FSP27 as a molecular node connecting metabolic regulation with cognitive health and identify it as a promising target for therapeutic intervention in neurodegenerative and cognitive disorders. Significance StatementFSP27, previously known for its role in lipid metabolism, is now revealed to be a critical regulator of brain function. Our study provides the first direct evidence that FSP27 supports learning and memory by maintaining neuronal integrity and regulating neurocognitive gene networks. These findings uncover an unexpected metabolic- cognitive link and position FSP27 as a promising molecular target for therapeutic strategies aimed at preventing or treating neurodegenerative and cognitive disorders.