Single-cell landscape of human adipose tissue reveals THBS1 as a potential driver of fibro-inflammation in metabolic disease

The cellular complexity of adipose tissue plays a critical role in the pathogenesis of metabolic disease; however, mechanisms underlying adipose dysfunction remain poorly understood. Here, we constructed a single-nucleus and bulk transcriptomic atlas of human visceral adipose tissues from an ethnically homogeneous cohort with defined metabolic states: lean with normal glucose tolerance, obesity, and obesity with type 2 diabetes. Single-nucleus RNA sequencing (snRNA-seq) revealed a fibro-inflammatory subpopulation of adipose stem cells and adipocytes characterized by high THBS1 expression, which were enriched in individuals with obesity and obesity with type 2 diabetes compared to lean controls. Through complementary in vitro (human primary ASCs, THP-1 macrophages, and Matrigel-captured mature adipocytes), ex vivo (mouse and human visceral adipose tissue explants), and in vivo (gain-of-function and antibody-mediated neutralization) experiments, we demonstrated that THBS1 promoted adipose fibrosis and inflammation via macrophage-mediated TGFβ activation, impairing adipogenesis and adipocyte function. Inhibition of THBS1 attenuated fibro-inflammatory features in metabolically dysfunctional adipose tissues. Moreover, THBS1 levels in plasma and adipocytes correlated with metabolic traits, including BMI and HbA1c. Collectively, our study provides a cellular atlas of human visceral adipose tissues across metabolic disease states and identifies THBS1 as a key pathogenic driver and potential therapeutic target.