Loss of Hematopoietic Cell–Derived Oncostatin M Worsens Diet-Induced Dysmetabolism in Mice

Innate immune cells infiltrate growing adipose tissue and propagate inflammatory clues to metabolically distant tis-sues, thereby promoting glucose intolerance and insulin resistance. Cytokines of the IL-6 family and gp130 ligands are among such signals. The role played by oncostatin M (OSM) in the metabolic consequences of overfeeding is debated, at least in part, because prior studies did not dis-tinguish OSM sources and dynamics. Here, we explored the role of OSM in metabolic responses and used bone marrow transplantation to test the hypothesis that hema-topoietic cells are major contributors to the metabolic effects of OSM. We show that OSM is required to adapt during the development of obesity because OSM concentrations are dynamically modulated during high-fat diet (HFD) and Osm-/- mice displayed early-onset glucose in-tolerance, impaired muscle glucose uptake, and wors-ened liver inflammation and damage. We found that OSM is mostly produced by blood cells and deletion of OSM in hematopoietic cells phenocopied glucose intolerance of whole-body Osm-/- mice fed a HFD and recapitulated liver damage with increased aminotransferase levels. We thus uncovered that modulation of OSM is involved in the metabolic response to overfeeding and that hematopoi-etic cell–derived OSM can regulate metabolism, likely via multiple effects in different tissues.