Oral Presentation Australian Diabetes Society and the Australian Diabetes Educators Association Annual Scientific Meeting 2016

Identification of an interferome nexus as a paradoxical negative regulator of adipogenesis and positive regulator of local and systemic insulin sensitivity (#21)

Jon Whitehead 1
  1. Mater Research Institute, University of Queensland, Brisbane, QLD, Australia

Coordinated adipogenesis helps maintain adipose tissue function and reduce obesity-associated complications including type 2 diabetes.  We previously demonstrated that FGF-1 promotes adipogenesis via a novel BAMBI/PPARg-dependent pathway.  Here, we employed a combination of RNA-Seq, functional investigations and association studies to identify novel downstream regulators of adipogenesis implicated in the modulation of local and systemic insulin sensitivity.  FGF-1 altered the expression of 598 genes, including 49 ‘interferome’ genes, of which 11 were downstream of BAMBI and PPARg.  In silico analysis of known and predicted protein-protein interactions revealed a nexus that included all 11 FGF-1/BAMBI/PPARg-dependent genes.  Functional characterization of five nexus genes revealed all were negative regulators of adipogenesis.  Determination of the expression profile of the nexus genes in subcutaneous human adipose tissue from a cohort of obese males with varying degrees of insulin sensitivity showed expression of all five nexus genes correlated with local (adipose) and systemic (skeletal muscle) insulin sensitivity.  This contrasted with a classic inflammatory gene signature which showed the expected inverse correlation with insulin sensitivity.  Moreover, in a cohort of subjects without overt metabolic dysfunction expression of both interferome nexus genes and inflammatory genes showed a positive correlation with BMI.  Collectively these findings increase our understanding of the molecular networks that regulate adipogenesis and, somewhat paradoxically, reveal the interferome nexus as a potential positive regulator of both local and systemic insulin sensitivity.  Further studies are warranted to explore the molecular mechanisms and define potential therapeutic opportunities.