FIG. 4.

The role of HO-1 and PGC-1α in maintaining mitochondrial function. Under normal diet, high levels of adiponectin secreted for “healthy” adipocytes increase the activity of HO-1 and PGC-1α that are important to mitochondrial and, subsequently, cardiac function. Under high-fat diet condition, ROS and RNS levels are increased, and inflamed dysfunctional adipocytes secrete less adiponectin, resulting in reduced levels and activity of HO-1 and PGC-1α, reduced level of mitochondrial fusion proteins, and impaired mitochondrial function, culminating in cardiac metabolic dysfunction, inflammation, and fibrosis and the development of diabetic cardiomyopathy. Color images are available online.