Lei Liu1,2, Tianyi Zhang2, Jingyao Hu2, Rui Ma3, Bing He3, Mofei Wang2, Yong Wang4. 1. Department of General Surgery, Shengjing Hospital of China Medical University, Shenyang, 110004, People's Republic of China. 2. Department of General Surgery, The Forth Hospital of China Medical University, Shenyang, 110032, People's Republic of China. 3. Department of Endocrinology, Shengjing Hospital of China Medical University, Shenyang, 110004, People's Republic of China. 4. Department of General Surgery, The Forth Hospital of China Medical University, Shenyang, 110032, People's Republic of China. wangyong@cmu.edu.cn.
Abstract
PURPOSE: White adipose tissue (WAT) browning plays a crucial role in energy metabolism. However, it remains unclear whether WAT browning is involved in the adipose reduction following sleeve gastrectomy (SG). Adiponectin is upregulated after Roux-en-Y gastric bypass surgery. The role of adiponectin in SG was further investigated in the current study. MATERIALS AND METHODS: Diabetic Sprague Dawley rats were randomly divided into control, sham + libitum, sham + food restriction, and sleeve groups. Browning markers, including uncoupling protein 1 (UCP1), peroxisome proliferator-activated receptor (PPAR) γ, and PPARγ coactivator-1 alpha (PGC-1α), were examined 4 weeks after the operation. RESULTS: UCP1, PPARγ, and PGC-1α expression were significantly higher in the sleeve group compared to the other study groups. The adipose tissue of the sleeve group exhibited tissue weight loss and additional morphological browning features. In addition, adiponectin expression in the sleeve group was significantly increased. Adiponectin upregulated the expression of the browning genes and sirtuin 1 (SIRT1) in 3T3-L1 adipocytes. SIRT1 could increase the WAT browning levels, revealing that adiponectin induced the browning process via the upregulation of SIRT1. Furthermore, SIRT1 represented a positive regulatory feedback loop for adiponectin. SIRT1 activated adenosine monophosphate-activated protein kinase (AMPK), which can mediate WAT browning. Inhibition of the AMPK signaling pathway by dorsomorphin decreased UCP1, PPARγ, and PGC-1α expression. However, additional studies are needed to understand the relationship between adiponectin and glucose homeostasis. CONCLUSIONS: Sleeve gastrectomy increased adiponectin levels, which in turn upregulated SIRT1. Thus, SIRT1 may function as an endocrine signal to mediate WAT browning.
PURPOSE: White adipose tissue (WAT) browning plays a crucial role in energy metabolism. However, it remains unclear whether WAT browning is involved in the adipose reduction following sleeve gastrectomy (SG). Adiponectin is upregulated after Roux-en-Y gastric bypass surgery. The role of adiponectin in SG was further investigated in the current study. MATERIALS AND METHODS: Diabetic Sprague Dawley rats were randomly divided into control, sham + libitum, sham + food restriction, and sleeve groups. Browning markers, including uncoupling protein 1 (UCP1), peroxisome proliferator-activated receptor (PPAR) γ, and PPARγ coactivator-1 alpha (PGC-1α), were examined 4 weeks after the operation. RESULTS: UCP1, PPARγ, and PGC-1α expression were significantly higher in the sleeve group compared to the other study groups. The adipose tissue of the sleeve group exhibited tissue weight loss and additional morphological browning features. In addition, adiponectin expression in the sleeve group was significantly increased. Adiponectin upregulated the expression of the browning genes and sirtuin 1 (SIRT1) in 3T3-L1 adipocytes. SIRT1 could increase the WAT browning levels, revealing that adiponectin induced the browning process via the upregulation of SIRT1. Furthermore, SIRT1 represented a positive regulatory feedback loop for adiponectin. SIRT1 activated adenosine monophosphate-activated protein kinase (AMPK), which can mediate WAT browning. Inhibition of the AMPK signaling pathway by dorsomorphin decreased UCP1, PPARγ, and PGC-1α expression. However, additional studies are needed to understand the relationship between adiponectin and glucose homeostasis. CONCLUSIONS: Sleeve gastrectomy increased adiponectin levels, which in turn upregulated SIRT1. Thus, SIRT1 may function as an endocrine signal to mediate WAT browning.
Authors: Nancy Puzziferri; Thomas B Roshek; Helen G Mayo; Ryan Gallagher; Steven H Belle; Edward H Livingston Journal: JAMA Date: 2014-09-03 Impact factor: 56.272
Authors: Garron T Dodd; Stephanie Decherf; Kim Loh; Stephanie E Simonds; Florian Wiede; Eglantine Balland; Troy L Merry; Heike Münzberg; Zhong-Yin Zhang; Barbara B Kahn; Benjamin G Neel; Kendra K Bence; Zane B Andrews; Michael A Cowley; Tony Tiganis Journal: Cell Date: 2015-01-15 Impact factor: 41.582