Effect of fat acids [saturated and polyunsaturated (é3)] on adipogenesis

• Grant number: 12/07026-2
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: July 01, 2012
• End date: June 30, 2013
• Field of knowledge: Biological Sciences - Physiology - Physiology of Organs and Systems
• Principal Investigator: Maria Isabel Cardoso Alonso-Vale
• Grantee: Lucas Curtolo Poiani
• Host Institution: Instituto de Ciências Ambientais, Químicas e Farmacêuticas (ICAQF). Universidade Federal de São Paulo (UNIFESP). Campus Diadema. Diadema , SP, Brazil

Abstract

Obesity is a result of a chronic imbalance between energy expenditure and energy uptake, which results in the cumulative storage of fat in the white adipose tissue. The morbidities associated with obesity are well described and include dyslipidemia, insulin resistance, type 2 diabetes (T2DM), hypertension, and cardiovascular disease, all of which contribute to increased mortality. Increases in adipose tissue arise as a consequence of both hyperplasia (increase in fat cell number) and hypertrophy (increase in fat cell size). The regulation of adipose tissue size mass is complex. Hyperplasia relies on pre-adipocyte proliferation and differentiation into mature adipocytes. Adipocyte differentiation (or adipogenesis) is a tightly regulated process orchestrated by the temporal expression of key transcription factors resulting in cytoskeletal changes as well as the induction of key genes involved in lipid metabolism, namely lipogenesis, and fatty acid uptake, lipolysis, and b-oxidation. In mature adipocytes, the relative balance of these processes is crucial in determining adipocyte size. Increased lipogenesis and fatty acid uptake favor lipid accumulation within the adipocyte, whilst lipolysis and b-oxidation promote lipid loss. This project aims to determine the effect of the saturated (palmitic acid [PA, C16: 0) and polyunsaturated (docosahexaenoic acid [DHA, C22: 6 n-3] fatty acid on adipogenesis. Therefore, the 3T3-L1 cell line will be cultured in a DMEM medium until confluence; differentiation will be induced by the addition of the adipogenic cocktail for 48 h in the presence or absence of such fatty acids. The culture will extend for 6 days, during which the cells will be harvest for posterior studies. The adipogenic potential will be assessed by temporal differentiation of preadipocytes, followed by an analysis of gene expression of adipogenic transcription factors and proteins (PPAR³, CEBP±, CEBP², aP2/FABP4, AdipoQ) by real-time RT-PCR, analysis of lipid content and staining with oil red O. Cytotoxicity studies of fatty acids by flow cytometry (in order to determine the optimal concentrations for this model) will be also performed.(AU)