Lipid Droplets accumulate in the hypothalamus of mice and humans with and without metabolic diseases

BACKGROUND: In peripheral tissues, the lipid droplet (LD) organelle links lipid metabolism, inflammation and insulin resistance. Little is known about the brain LDs.

OBJECTIVES: We hypothesised that hypothalamic LDs would be altered in metabolic diseases.

METHODS: We used immunofluorescence for the specific LD protein, PLIN2, as the marker to visualize and quantify LDs.

RESULTS: LDs were abundant in the hypothalamic third ventricle (3V) wall layer with similar heterogeneous distributions between control mice and humans. The LD content was enhanced by HFD in both WT and in low-density lipoprotein receptor deficient (Ldlr -/- HFD) mice. Strikingly, we observed a lower LD amount in T2DM patients when compared with non-T2DM, patients.

CONCLUSIONS: LDs accumulate in the normal hypothalamus, with similar distributions in human and mouse. Moreover, metabolic diseases differently modify LD content in mouse and human. Our results point hypothalamic LDs accumulation as an important target to the study of metabolism.