Heme Oxygenase-1 Drives Metaflammation and Insulin Resistance in Mouse and Man

Authors
Alexander Jais,Elisa Einwallner, Omar Sharif, Klaus Gossens et al.

Lab
Medical University of Vienna, Vienna, Austria

Journal
Cell

Abstract
Obesity and diabetes affect more than half a billion individuals worldwide. Interestingly, the two conditions do not always coincide and the molecular determinants of “healthy” versus “unhealthy” obesity remain ill-defined. Chronic metabolic inflammation (metaflammation) is believed to be pivotal. Here, we tested a hypothesized anti-inflammatory role for heme oxygenase-1 (HO-1) in the development of metabolic disease. Surprisingly, in matched biopsies from “healthy” versus insulin-resistant obese subjects we find HO-1 to be among the strongest positive predictors of metabolic disease in humans. We find that hepatocyte and macrophage conditional HO-1 deletion in mice evokes resistance to diet-induced insulin resistance and inflammation, dramatically reducing secondary disease such as steatosis and liver toxicity. Intriguingly, cellular assays show that HO-1 defines prestimulation thresholds for inflammatory skewing and NF-?B amplification in macrophages and for insulin signaling in hepatocytes. These findings identify HO-1 inhibition as a potential therapeutic strategy for metabolic disease.

BIOSEB Instruments Used:
OXYLET, Indirect Calorimeter (OXYLET)