Poster only 3rd Metabolic Diseases; Breakthrough Discoveries in Diabetes & Obesity 2022

Ceramides control the level of Coenzyme Q in mitochondria providing the basis for an Insulin Resistance Stress Pathway. (#61)

Alexis Diaz 1 , James Burchfield 1 , Luke Carroll 1 , Kristen Thomas 1 , Anthony Don 1 , Joseph Brozinick 2 , David James 1
  1. Charles Perkins Centre, School of Life and Environmental Sciences, University of Sydney, Sydney, Australia., Sydney, New South Wales, Australia
  2. Lilly Research Laboratories, Division of Eli Lilly and Company, Indianapolis, IN, USA

Many intracellular stressors have been linked to insulin resistance, including lipids such as ceramides, mitochondrial reactive oxygen species, and Coenzyme Q. Whether these molecules cause insulin resistance independently or via some interconnected insulin resistance stress pathway is unknown. Here, we demonstrate a reciprocal relationship between ceramide and CoQ levels in mitochondria. Elevated mitochondrial ceramide in skeletal muscle cells results in CoQ depletion and insulin resistance, which can be reversed by CoQ supplementation. Conversely, decreasing mitochondrial ceramide increased CoQ levels in vitro and in animal models, protecting against insulin resistance. All these manipulations occurred independently of significant changes in proximal insulin-regulated signalling such as Akt phosphorylation. Collectively, these data indicate that this mitochondrial Ceramide-CoQ nexus may represent the foundation of a generic Insulin Resistance Stress Pathway that may play a critical role in other diseases associated with ceramide accumulation, including heart failure and cancer.