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Losby, M.

Publications and source records attributed to Losby, M..

2 recordsLinked to original sources

The Estrogen Receptor-Related Orphan Receptors (ERRs) Regulate Autophagy through TFEB

Autophagy is an essential self-degradative and recycling mechanism that maintains cellular homeostasis. Estrogen receptor-related orphan receptors (ERRs) play fundamental role in regulation of cardiac metabolism and function. Previously, we showed that ERR agonists improve cardiac function in models of heart failure and induce autophagy in cardiomyocytes. Here, we characterized a mechanism by which ERRs induce autophagy in cardiomyocytes. Transcription factor EB (TFEB) is a master regulator of the autophagy-lysosome pathway and has been shown to be important in cardiac autophagy. We discovered that TFEB is a direct ERR target gene whose expression is induced by ERR agonists. Activation of ERR results in increased TFEB expression in both neonatal rat ventricular myocytes and C2C12 myoblasts. ERR-dependent increases in TFEB expression results in increased expression of an array of TFEB target genes, which are critical for stimulation of autophagy. Pharmacologically targeting ERR is a promising potential method for treatment of many diseases where stimulation of autophagy may be therapeutic including heart failure.

cell biology↗

Novel ERR pan-agonists ameliorate heart failure through boosting cardiac fatty acid metabolism and mitochondrial function

Cardiac metabolic dysfunction is a hallmark of heart failure. Estrogen related receptors ERR and ERR{gamma} are essential regulators for cardiac metabolism. Therefore, activation of ERR could be a potential therapeutic intervention for heart failure. However, no natural or synthetic ERR agonist is available to demonstrate their pharmacological effect in vivo. Using a structure-based design approach, we designed and synthesized two structurally distinct pan-ERR agonists, SLU-PP-332 (332) and SLU-PP-915 (915), which significantly improved ejection fraction and ameliorated fibrosis against pressure overload-induced heart failure without affecting cardiac hypertrophy. Mechanistically, a broad-spectrum of metabolic genes were transcriptionally activated by ERR agonists, particularly genes involved in fatty acid metabolism and mitochondrial function, which were mainly mediated by ERR{gamma}. Metabolomics analysis showed significant normalization of metabolic profiles in fatty acid/lipid and TCA/OXPHOS metabolites by 915 in the mouse heart with 6-week pressure overload. Autophagy was also induced by ERR agonists in cardiomycoyte. On the other hand, ERR agonism led to downregulation of cell cycle and development pathways, which was partially mediated by E2F1 in cardiomyocyte. In summary, ERR agonists maintain oxidative metabolism, which confers cardiac protection against pressure overload-induced heart failure in vivo. Our results provided direct pharmacological evidence supporting the further development of ERR agonists as novel heart failure therapeutics in vivo.

pharmacology and toxicology↗