Loss of hematopoietic cell-derived oncostatin M worsens dietinduced dysmetabolism in mice.

Innate immune cells infiltrate growing adipose and propagate inflammatory clues to metabolically distant tissues, 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 distinguish OSM sources and dynamics. Here, we explored the role of OSM in metabolic responses and used bone marrow transplantation to test the hypothesis that hematopoietic cells are major contributors to the metabolic effects of OSM. We show that OSM is required to adapt during the development of obesity as OSM concentrations are dynamically modulated during high-fat diet (HFD) and Osm-/- mice displayed early-onset glucose intolerance, impaired muscle glucose uptake, worsened liver inflammation and damage. We found that OSM is mostly produced by blood cells, and that deletion of OSM in hematopoietic cells phenocopied glucose intolerance of whole-body Osm-/- mice on HFD, and recapitulated liver damage with increased aminotransferase levels. We thus uncover that modulation of OSM is involved in the metabolic response to overfeeding and that hematopoietic cell-derived OSM can regulate metabolism, likely via multiple effects in different tissues.