| Institution: | 1. Metabolic Biology Laboratory, Lewis Katz School of Medicine at Temple University, Center for Translational Medicine, Department of Pharmacology, Philadelphia, USA;2. Institute of Molecular Biosciences, University of Graz, Graz, Austria;3. Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT, USA;4. Inflammatory Bowel Disease Center and Neuroendocrine Assay Core, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA;5. Howard Hughes Medical Institute, Department of Pathology, NYU School of Medicine, New York, NY, USA;6. Division of Preventive Medicine and Nutrition, Columbia University, New York, NY 10032, USA |
| Abstract: | Cardiac metabolism affects systemic energetic balance. Previously, we showed that Krüppel-like factor (KLF)-5 regulates cardiomyocyte PPARα and fatty acid oxidation-related gene expression in diabetes. We surprisingly found that cardiomyocyte-specific KLF5 knockout mice (αMHC-KLF5?/?) have accelerated diet-induced obesity, associated with increased white adipose tissue (WAT). Alterations in cardiac expression of the mediator complex subunit 13 (Med13) modulates obesity. αMHC-KLF5?/? mice had reduced cardiac Med13 expression likely because KLF5 upregulates Med13 expression in cardiomyocytes. We then investigated potential mechanisms that mediate cross-talk between cardiomyocytes and WAT. High fat diet-fed αMHC-KLF5?/? mice had increased levels of cardiac and plasma FGF21, while food intake, activity, plasma leptin, and natriuretic peptides expression were unchanged. Consistent with studies reporting that FGF21 signaling in WAT decreases sumoylation-driven PPARγ inactivation, αMHC-KLF5?/? mice had less SUMO-PPARγ in WAT. Increased diet-induced obesity found in αMHC-KLF5?/? mice was absent in αMHC-KLF5?/?;FGF21?/?] double knockout mice, as well as in αMHC-FGF21?/? mice that we generated. Thus, cardiomyocyte-derived FGF21 is a component of pro-adipogenic crosstalk between heart and WAT. |
