A low-protein, high-carbohydrate diet increases browning in perirenal adipose tissue but not in inguinal adipose tissue

作者：Pereira Mayara P; Ferreira Lais A A; da Silva Flavia H S; Christoffolete Marcelo A; Metsios George S; Chaves Valeria E; de Franca Suelem A; Damazo Amilcar S; Flouris Andreas D; Kawashita Nair H^*

来源：Nutrition, 2017, 42: 37-45.

DOI：10.1016/j.nut.2017.05.007

• Brite
• Protein restriction
• Energy expenditure
• Low-protein
• High-carbohydrate diet
• White adipose tissue

Objective: The aim of this study was to evaluate the browning and origin of fatty acids (FAs) in the maintenance of triacylglycerol (TG) storage and/or as fuel for thermogenesis in perirenal adipose tissue (periWAT) and inguinal adipose tissue (ingWAT) of rats fed a low-protein, high-carbohydrate (LPHC) diet.
Methods: LPHC (6% protein, 74% carbohydrate) or control (C; 17% protein, 63% carbohydrate) diets were administered to rats for 15 d. The tissues were stained with hematoxylin and eosin for histologic analysis. The content of uncoupling protein 1 (UCP1) was determined by immunofluorescence. Levels of T-box transcription factor (TBX1), PR domain containing 16 (PRDM16), adipose triacylglycerol lipase (ATGL), hormone-sensitive lipase, lipoprotein lipase (LPL), glycerokinase, phosphoenolpyruvate carboxykinase (PEPCK), glucose transporter 4, beta(3)-adrenergic receptor (AR), beta(1)-AB, protein kinase A (PICA), adenosine-monophosphate-activated protein kinase (AMPK), and phospho-AMPK were determined by immunoblotting. Serum fibroblast growth factor 21 (FGF21) was measured using a commercial kit (Student's t tests, P < 0.05).
Results: The LPHC diet increased FGF21 levels by 150-fold. The presence of multilocular adipocytes, combined with the increased contents of UCP1, TBX1, and PRDM16 in periWAT of LPHC-fed rats, suggested the occurrence of browning. The contents of beta(1)-AR and LPL were increased in the periWAT. The ingWAT showed higher ATGL and PEPCK levels, phospho-AMPK/AMPK ratio, and reduced beta(3)-AR and PICA levels.
Conclusion: These findings suggest that browning occurred only in the periWAT and that higher utilization of FAs from blood lipoproteins acted as fuel for thermogenesis. Increased glycerol 3-phosphate generation by glyceroneogenesis increased FAs reesterification from lipolysis, explaining the increased TG storage in the ingWAT.

• 出版日期2017-10