HMOX1 and diabetic cardiomyopathy: Finally, induction of heme oxygenase-1 (HO-1) was shown to enhance M2 macrophage polarization in vitro and in rodent models, including high fat diet-fed C57BL/6 mice and ZDF rats, which led to the amelioration of pro-inflammatory cytokine generation and cardiac dysfunction in the face of diabetic cardiomyopathy (Sierra-Filardi et al., 2010; Jadhav et al., 2013; Tu et al., 2014).