1. Glucocorticoid chronopharmacology promotes glucose metabolism in heart through a cardiomyocyte-autonomous transactivation program.
- Author
-
Durumutla HB, Prabakaran AD, El Abdellaoui Soussi F, Akinborewa O, Latimer H, McFarland K, Piczer K, Werbrich C, Jain MK, Haldar SM, and Quattrocelli M
- Subjects
- Animals, Mice, Male, Circadian Rhythm drug effects, Transcriptional Activation drug effects, Insulin Resistance, Myocytes, Cardiac metabolism, Myocytes, Cardiac drug effects, Glucose metabolism, Kruppel-Like Transcription Factors metabolism, Kruppel-Like Transcription Factors genetics, Receptors, Glucocorticoid metabolism, Glucocorticoids pharmacology
- Abstract
Circadian time of intake gates the cardioprotective effects of glucocorticoid administration in both healthy and infarcted hearts. The cardiomyocyte-specific glucocorticoid receptor (GR) and its cofactor, Krüppel-like factor 15 (KLF15), play critical roles in maintaining normal heart function in the long term and serve as pleiotropic regulators of cardiac metabolism. Despite this understanding, the cardiomyocyte-autonomous metabolic targets influenced by the concerted epigenetic action of the GR/KLF15 axis remain undefined. Here, we demonstrated the critical roles of the cardiomyocyte-specific GR and KLF15 in orchestrating a circadian-dependent glucose oxidation program within the heart. Combining integrated transcriptomics and epigenomics with cardiomyocyte-specific inducible ablation of GR or KLF15, we identified their synergistic role in the activation of adiponectin receptor expression (Adipor1) and the mitochondrial pyruvate complex (Mpc1/2), thereby enhancing insulin-stimulated glucose uptake and pyruvate oxidation. Furthermore, in obese diabetic (db/db) mice exhibiting insulin resistance and impaired glucose oxidation, light-phase prednisone administration, as opposed to dark-phase prednisone dosing, restored cardiomyocyte glucose oxidation and improved diastolic function. These effects were blocked by combined in vivo knockdown of GR and KLF15 levels in db/db hearts. In summary, this study leveraged the circadian-dependent cardioprotective effects of glucocorticoids to identify cardiomyocyte-autonomous targets for the GR/KLF15 axis in glucose metabolism.
- Published
- 2024
- Full Text
- View/download PDF