Regulation of the Fibrosis and Angiogenesis Promoter SPARC/Osteonectin in Human Adipose Tissue by Weight Change, Leptin, Insulin, and Glucose

• DOI: 10.2337/db09-0211
• Publication Date: 2009-06-10T03:44:10Z
• Authors: Katrina Kos; Steve Wong; Bee Tan; Anders Gummesson; Margareta Jernas; Niclas Franck; David Kerrigan; Fredrik H. Nystrom; Lena M.S. Carlsson; Harpal S. Randeva; Jonathan H. Pinkney; John P.H. Wilding
• Keywords: Osteonectin; Adipose tissue macrophages

Matricellular Secreted Protein, Acidic and Rich in Cysteine (SPARC), originally discovered bone as osteonectin, is a mediator of collagen deposition promotes fibrosis. Adipose tissue has recently been found to be linked with metabolic dysregulation. Therefore, we tested the hypothesis that SPARC human adipose influenced by glucose metabolism adipokines.Serum biopsies were obtained from morbidly obese nondiabetic subjects undergoing bariatric surgery lean control for analysis markers, SPARC, various cytokines (RT-PCR). Additionally, 24 underwent very-low-calorie diet 1,883 kJ (450 kcal)/day 16 weeks serial subcutaneous-abdominal-adipose (SCAT) (weight loss: 28 +/- 3.7 kg). Another six fast-food-based hyperalimentation 4 gain: 7.2 1.6 Finally, visceral explants cultured recombinant leptin, insulin, glucose, mRNA protein expression determined Western blot analyses.SPARC correlated fat mass was higher SCAT. Weight loss induced lowered 33% increased 30% gaining weight after fast-food diet. leptin independent homeostasis model assessment-insulin resistance. In vitro experiments showed insulin potently production dose dependently explants, while decreased protein.Our data suggest predominant subcutaneous its secretion are mass, glucose. The profibrotic effects may contribute dysregulation obesity.