Protection Strategies Against Palmitic Acid-Induced Lipotoxicity in Metabolic Syndrome and Related Diseases

Targeting FABP4 to Inhibit AGEs-RAGE/NF-κB Signalling Effectively Ameliorates Nucleus Pulposus Dysfunction and Angiogenesis in Obesity-Related Intervertebral Disc Degeneration

Intervertebral disc degeneration (IVDD) is a primary contributor to low back pain, posing significant social and economic burdens. Increasing evidence shows that obesity contributes to IVDD, yet the underlying mechanisms remain elusive. Here, we firstly revealed a causal correlation between obesity and IVDD via a two-sample mendelian randomization analysis and identified fatty acid-binding protein 4 (FABP4) as the potential regulator to associate IVDD and obesity. Elevated FABP4 expression promoted extracellular matrix (ECM) disequilibrium and angiogenesis to exacerbate IVDD progression. Genetically knocking out or pharmacologically inhibiting FABP4 in high-fat diet-induced mice alleviated IVDD. Mechanistically, obesity activated the mammalian target of rapamycin complex 1 (mTORC1), which upregulated FABP4 expression, leading to the accumulation of advanced glycation end-products (AGEs) in intervertebral disc tissue. AGEs further activated the NF-κB signalling pathway, exacerbating ECM degradation and neovascularization. Conversely, rapamycin-mediated inhibition of mTORC1 suppressed FABP4 expression in nucleus pulposus cells (NPCs), alleviating IVDD in vivo. Collectively, our findings reveal a critical role of the obesity-induced mTORC1-FABP4 axis in ECM degradation and angiogenesis during IVDD progression. Targeting FABP4 may represent a promising therapeutic strategy for IVDD in obese individuals.