Hypothalamic astrocytes: connecting brain and periphery in metabolic control

Astrocytes, once viewed primarily as supportive cells in the central nervous system, are increasingly recognized as dynamic regulators in the regulation of systemic metabolism, especially within the hypothalamus. Recent research highlights their capacity to sense and integrate nutrient, hormonal, and circadian signals, modulate hypothalamic circuits, and ultimately influence whole-body energy balance. In this review, we discuss emerging studies that explore how hypothalamic astrocytes regulate glucose and lipid metabolism through neuroendocrine and autonomic pathways that extend their influence to peripheral organs. We examine emerging evidence showing that astrocytes contribute to glycemic control via glucose sensing, intracellular metabolic shifts, and modulation of key neuronal circuits. Similarly, recent investigations have identified roles for astrocytes in the regulation of adipose tissue function and body weight, particularly in the context of high-fat diet exposure, largely through their influence on hypothalamic neuron-astrocyte interactions and sympathetic output. We further consider recent findings implicating astrocytic circadian pathways in the coordination of metabolic rhythms, as well as the long-term consequences of early-life nutritional exposures, that may epigenetically program hypothalamic astrocyte function. New insights also point to region-specific and sex-dependent astrocytic functions. Together, this growing body of work positions hypothalamic astrocytes as integrators of brain-body communication in the control of energy homeostasis and highlights their potential relevance in the pathophysiology of obesity and metabolic disease.