Adipose tissue in communication: within and without

Adipose tissue is highly versatile, dynamic and essential for metabolic health. In 2022, several exciting discoveries provided a high-resolution view of cellular composition and cell–cell communication within the adipose niche, and revealed how adipose tissue communicates with other organs and modulates metabolism during normal and pathophysiological states. Key advances Single-cell mapping of human and mouse white adipose tissue across different depots and body masses revealed cellular heterogeneity, and identified distinct subpopulations of adipocytes, adipose progenitors and immune cells across species and types of diet 2 . In obesity, T-bet + B cells, which express the T helper 1-lineage transcription factor T-bet, accumulated in the adipose tissue of humans and mice, and activated T-bet + B cells secreted the proinflammatory chemokine CXCL10 to exacerbate obesity-associated metabolic abnormalities 5 . Extracellular vesicles (EVs) produced by dysfunctional adipose tissue could deliver microRNAs to the brain and cause synaptic damage in the hippocampus and cognitive impairments; targeting adipose tissue-derived EVs or microRNAs prevented cognitive defects in mice 7 . Cold exposure inhibited tumour growth in mice carrying various xenografted solid tumours, an effect mediated via the activation of brown adipose tissue, leading to decreased circulating levels of glucose and attenuated glycolytic and lipid metabolism in tumours 8 . SARS-CoV-2 directly infected human adipocytes and altered cell metabolism in a depot-specific and viral lineage-dependent fashion; visceral adipocytes were more susceptible to SARS-CoV-2 infection than subcutaneous adipocytes 10 .