ODP005 Molecular Characterization of Early Adipose Tissue Remodeling and Fibrosis in a Murine Model of Diet-Induced Obesity.

Abstract One of the many pathophysiological changes associated with obesity is the build up of structural and physiochemical extracellular matrix components in adipose depots, known as adipose tissue fibrosis. Like liver fibrosis, adipose tissue fibrosis occurs as a response to chronic injury and inflammation and can perpetuate inflammation and impede proper tissue functioning. Key adipose tissue fibrosis markers have been identified in obese adipose tissue, including collagen VI and its cleavage product endotrophin, however, adipose tissue fibrosis remains poorly characterized, particularly in its initiating phases. We have developed and characterized a murine model of diet-induced obesity (12 weeks of high fat feeding), insulin resistance, and early fibrotic development in both sexes. While diagnosable fibrosis was absent, as determined by picrosirius red staining, we detected elevated collagen VI, TGF-β, TNF-α, and TIMP-1 mRNA in gonadal white adipose of both sexes. TIMP-4 was decreased in males but elevated in females. Immunohistochemical analysis revealed pericellular build up of collagen VI immunoreactivity in males only, co-localized with immunoreactivity of its protease MMP-14, which is known to generate the pro-fibrotic fragment endotrophin. This work identifies key sex differences and fibrosis markers present during the initiation of adipose tissue fibrosis, earlier than diagnosable fibrosis can be detected, highlighting their potential as therapeutic targets for prevention or reversal of fibrosis in the treatment of obesity and insulin resistance. Presentation: No date and time listed