Ado-Mediated Depletion of Taurine Impairs Mitochondrial Respiratory Capacity and Alters the Chromatin Landscape of Inguinal Adipose Tissue

Non-shivering thermogenesis (NST) has strong potential to combat obesity; however, a safe molecular approach to activate this process has not yet been identified. The sulfur amino acid taurine has the ability to safely activate NST and confer protection against obesity and metabolic disease in both mice and humans, but the mechanism of this action is unknown. In this study, we discover that a suite of taurine biosynthetic enzymes, especially that of cysteamine dioxygenase (ADO), significantly increases in response to β3 adrenergic signaling in inguinal adipose tissue (IWAT) in order to increase intracellular concentrations of taurine. We further show that ADO is critical for thermogenic mitochondrial respiratory function as its ablation in adipocytes significantly reduces taurine levels, which leads to declines in mitochondrial oxygen consumption rates. Finally, we demonstrate via assay for transposase-accessible chromatin with sequencing (ATAC-seq) that taurine supplementation in beige adipocytes has the ability to remodel the chromatin landscape to increase the chromatin accessibility and transcription of genes, such as glucose-6-phosphate isomerase 1 (Gpi1), which are critical for NST. Taken together, our studies highlight a potential mechanism for taurine in the activation of NST that can be leveraged toward the treatment of obesity and metabolic disease.