O papel da suplementação dietética com óleo de chia (Salvia hispanica L.) sobre o remodelamento morfofuncional do tecido adiposo branco em camundongos C57Bl/6

Abstract

The adipose tissue (AT) remodeling is a dynamic process in nutritional deprivation or excess situations. Impaired expansion of AT increases the risk of the development of obesity-associated comorbidities. Here, we investigated the effect of chia oil supplementation (COS) on white AT remodeling in eutrophic and obese mice and its implications for the metabolic health of these animals. Male C57Bl/6 mice at 30 days of age were fed with a chow control (Group C) or a high-fat diet (45% Kcal from fat) (Group H) for nine weeks. After this period, the groups were subdivided into the CC and HC groups, fed with respective diets supplemented with chia oil (1.5% w/w) for seven weeks. Chia oil supplementation increased fasting glucose, glucose tolerance, and serum LDL cholesterol levels in lean mice, reducing serum insulin levels without affecting body weight and composition. In subcutaneous (SAT) and epididymal (EAT) AT, COS significantly increased TNF-α secretion, while IL-10 levels increased only in EAT. Metabolomic analysis showed that COS induced a significant increase in lactate production by EAT without changes in glucose consumption. In obese mice, COS decreased body fat accumulation and increased fat-free mass. Besides, its improved glucose tolerance, reduced serum insulin, and triglyceride levels, and increased HDL cholesterol. In adipose tissue compartments, COS reduced the mass of the EAT, decreasing the area of its adipocytes. In SAT, COS did not change tissue mass but increased the cell number. Analysis of the profile of cytokines secreted showed that COS increased IL-10 production, reduced MCP-1 by SAT, and decreased IL-10 levels, increasing TNF-α levels by TAE. The proliferative potential and adipocytes' differentiation of mesenchymal stem cells (MSCs) from the stromal vascular fraction of SAT and EAT were evaluated. Chia oil supplemented obese mice showed inhibition of proliferative and differentiation response in SAT and increased differentiation in EAT. We also showed that SOC induced an increase in the gene expression of UCP-1 in SAT without changes in EAT. Metabolomics analysis showed that COS increased lactate secretion in TAE. The incubation of RAW264.7 macrophages with the conditioned medium of different adipose tissues (24 hours) did not induce the protein expression of iNOS and arginase. Our results show that COS in obese and eutrophic mice differently induces white adipose tissue remodeling in the subcutaneous and epididymal compartments and promotes an increase in insulin sensitivity. Furthermore, we have shown for the first time that obesity and chia oil supplementation modify the profile of metabolites secreted by the different compartments of fatty tissue. Still, more studies are needed to elucidate how each of these metabolites interferes in the stages involved in adipose tissue remodeling.