Ovarian hormones and high-fat diet duration distinctively modulate hypothalamic chemokine profile.

Excessive intake of saturated fats triggers inflammation in the hypothalamus, a key regulator of energy balance. In the chronic phase of this inflammatory response, bone marrow-derived and lymphoid cells are chemoattracted to this region, partially mitigating high-fat diet (HFD)-induced metabolic impairments. In rodents, the onset and magnitude of this inflammation differ between males and females, reflecting sex-specific patterns of metabolic regulation. However, how the hypothalamic chemokine profile evolves during HFD-induced inflammation, and whether it is influenced by biological sex, remains unclear. Here, male and female C57BL/6J mice were fed a HFD for 1, 3, 14, or 28 days. To isolate the role of ovarian hormones in modulating hypothalamic chemokine profile, we also analyzed ovariectomized (OVX) females with or without estrogen replacement. Quantitative polymerase chain reaction-based expression analysis revealed that most chemokines and their receptors were transiently modulated in the hypothalamus during the course of the HFD exposure, showing reduced levels in the acute phase and normalization during the chronic phase. Despite the modest sex-dependent effects observed, messenger RNA expression of the chemokine receptor C-X-C motif chemokine receptor 3 (CXCR3) was significantly higher in females than in males after 14 and 28 days of HFD, suggesting faster recruitment of CXCR3