Neural CXCR4 contributes to neuroimmune modulation of atherosclerosis in a cardio-metabolic Ldlr-/- mouse model
BackgroundAtherosclerosis is a chronic inflammatory disease characterized by metabolic and immune dysregulation. Emerging evidence suggests that specific central nervous system (CNS) regions modulate its progression via neuroimmune cardiovascular interfaces (NICIs). While the C-X-C motif chemokine receptor 4 (CXCR4) is known to participate in atherogenesis by regulating immune cell dynamics and vascular wall responses, the role of neural CXCR4 in atherosclerotic plaque formation remains unclear. MethodsWe generated a Nestin-Cre-mediated conditional Cxcr4 knockout mouse model on a low-density lipoprotein receptor-deficient (Ldlr-/-) background and fed these mice a western diet (WD) for up to 12 weeks to induce atherosclerosis. To evaluate the impact of neural CXCR4 function, we quantified atherosclerotic plaque burden, systemic metabolic parameters and circulating immune cell profiles, comparing neural Cxcr4-deficient mice with corresponding genetic controls. Spatial transcriptomics and RNAscope were employed to map Cxcr4 mRNA and its non-canonical ligand macrophage migration inhibitory factor (Mif) mRNA in neuroimmune-regulatory brain regions, and to assess diet-induced expression changes in relation to neuroinflammatory responses. ResultsNeural conditional deletion of Cxcr4 in Ldlr-/- mice significantly reduced atherosclerotic plaque formation in the aortic arch and aorta, without affecting body weight, lipid levels, glucose tolerance, or circulating immune cells. Cxcr4 gene expression was found to be uniformly low across hypothalamic subregions implicated in neuroimmune regulation of systemic inflammation and atherogenesis. Importantly, WD feeding did not modify this consistently low expression in male Ldlr-/- mice. In contrast, Mif mRNA expression was significantly upregulated in the PVN after 5-day WD feeding, but not after 8 weeks. Exploratory spatial transcriptomic analysis of PVN-containing coronal brain sections from male Ldlr-/- mice suggested that 5-day WD exposure is associated with MIF-CXCR4 signaling and downstream neuroinflammatory pathways in the PVN. ConclusionsThis study identifies neural CXCR4 as a component of neuroimmune modulation in atherosclerosis, exerting its effect independently of systemic metabolic or inflammatory changes. Short-term WD exposure activated gene expression of the CXCR4 ligand Mif in the PVN, pointing to a neuroimmune axis that may promote vascular inflammation and atherosclerotic plaque development. These findings establish a link between CNS CXCR4 and vascular disease and suggest that MIF-CXCR4-dependent neuroimmune pathways may play a role in cardiometabolic risk. Trial registrationNot applicable.