scholarly journals Effects of metformin on metabolism of white and brown adipose tissue in obese C57BL/6J mice

2019 ◽  
Vol 11 (1) ◽  
Author(s):  
Tao Yuan ◽  
Juan Li ◽  
Wei-Gang Zhao ◽  
Wei Sun ◽  
Shuai-Nan Liu ◽  
...  

Abstract Background To investigate effects of metformin on the regulation of proteins of white adipose tissue (WAT) and brown adipose tissue (BAT) in obesity and explore the underlying mechanisms on energy metabolism. Methods C57BL/6J mice were fed with normal diet (ND, n = 6) or high-fat diet (HFD, n = 12) for 22 weeks. HFD-induced obese mice were treated with metformin (MET, n = 6). After treatment for 8 weeks, oral glucose tolerance test (OGTT) and hyperinsulinemic–euglycemic clamp were performed to evaluate the improvement of glucose tolerance and insulin sensitivity. Protein expressions of WAT and BAT in mice among ND, HFD, and MET group were identified and quantified with isobaric tag for relative and absolute quantification (iTRAQ) coupled with 2D LC–MS/MS. The results were analyzed by MASCOT, Scaffold and IPA. Results The glucose infusion rate in MET group was increased significantly compared with HFD group. We identified 4388 and 3486 proteins in WAT and BAT, respectively. As compared MET to HFD, differential expressed proteins in WAT and BAT were mainly assigned to the pathways of EIF2 signaling and mitochondrial dysfunction, respectively. In the pathways, CPT1a in WAT, CPT1b and CPT2 in BAT were down-regulated by metformin significantly. Conclusions Metformin improved the body weight and insulin sensitivity of obese mice. Meanwhile, metformin might ameliorate endoplasmic reticulum stress in WAT, and affect fatty acid metabolism in WAT and BAT. CPT1 might be a potential target of metformin in WAT and BAT.

2021 ◽  
Vol 12 ◽  
Author(s):  
Long Cheng ◽  
Shuofeng Zhang ◽  
Fei Shang ◽  
Yibo Ning ◽  
Zhiqi Huang ◽  
...  

BackgroundAdipose tissue (e.g. white, brown and brite) plays a critical role in modulating energy metabolism. Activating brown adipose tissue (BAT) and inducing browning in white adipose tissue (WAT) has been proposed to be a potential molecular target for obesity treatment. Emodin is a natural anthraquinone derivative that exhibits variety of pharmacologic effects including lowering lipids and regulating glucose utilization. However, the underlying mechanism of action is still unclear. In the present study, we investigated whether emodin could alleviate obesity via promoting browning process in adipose tissue.MethodsC57BL/6J mice were fed with high fat diet to induce obesity. Emodin at the doses of 40 and 80 mg/kg were orally given to obesity mice for consecutive 6 weeks. Parameters including fasting blood glucose, oral glucose tolerance, blood lipids, and the ratios of subcutaneous white adipose tissue (scWAT) or BAT mass to body weight, and morphology of adipose tissue were observed. Besides, the protein expression of uncoupling protein 1 (UCP1) and prohibitin in BAT and scWAT was determined by immunohistochemistry method. Relative mRNA expression of Cd137, transmembrane protein 26 (Tmem26) and Tbx1 in scWAT was analyzed using qRT-PCR. And the protein expression of UCP1, CD36, fatty acid transporter 4 (FATP4), peroxisome proliferator-activated receptor alpha (PPARα) and prohibitin of scWAT and BAT were analyzed using western blotting. In addition, ultra-high-performance liquid chromatography with electrospray ionization tandem mass spectrometry was utilized to detect the small lipid metabolites of scWAT and BAT.ResultsEmodin decreased the body weight and food intake in HFD-induced obesity mice, and it also improved the glucose tolerance and reduced the blood lipids. Emodin treatment induced beiging of WAT, and more multilocular lipid droplets were found in scWAT. Also, emodin significantly increased markers of beige adipocytes, e.g. Cd137, Tmem26 and Tbx1 mRNA in scWAT, and UCP1, CD36, FATP4, PPARα and prohibitin protein expression in scWAT and BAT. Furthermore, emodin perturbed the lipidomic profiles in scWAT and BAT of obese mice. Emodin increased total ceramides (Cers), lysophosphatidylcholines (LPCs), lyso-phosphatidylcholines oxygen (LPCs-O), and phosphatidylethanolamines oxygen (PEs-O) species concentration in scWAT. Specifically, emodin significantly up-regulated levels of Cer (34:1), LPC (18:2), LPC-(O-20:2), PC (O-40:7), PE (O-36:3), PE (O-38:6), PE (O-40:6), and sphingolipid (41:0) [SM (41:0)], and down-regulated PC (O-38:0), PE (O-40:4), PE (O-40:5) in scWAT of obesity mice. In terms of lipid matabolites of BAT, the emodin remarkably increased the total PCs levels, which was driven by significant increase of PC (30:0), PC (32:1), PC (32:2), PC (33:4) and PC (38:0) species. In addition, it also increased species of LPCs, e.g. LPC (20:0), LPC (20:1), LPC (22:0), LPC (22:1), LPC (24:0), and LPC (24:1). Especially, emodin treatment could reverse the ratio of PC/PE in HFD-induced obese mice.ConclusionsThese results indicated that emodin could ameliorate adiposity and improve metabolic disorders in obese mice. Also, emodin could promote browning in scWAT and activate the BAT activities. In addition, emodin treatment-induced changes to the scWAT and BAT lipidome were highly specific to certain molecular lipid species, indicating that changes in tissue lipid content reflects selective remodeling in scWAT and BAT of both glycerophospholipids and sphingolipids in response to emodin treatment.


Author(s):  
Sriram Gubbi ◽  
Ranganath Muniyappa ◽  
Susmeeta T Sharma ◽  
Shivraj Grewal ◽  
Raven McGlotten ◽  
...  

Abstract Background Increased tissue cortisol availability has been implicated in abnormal glucose and fat metabolism in patients with obesity, metabolic syndrome, and type 2 diabetes (T2DM). Our objective was to evaluate whether blockade of glucocorticoid receptor (GR) with mifepristone ameliorates insulin resistance (IR) in overweight/obese subjects with glucose intolerance. Methods We conducted a randomized, double-blinded, placebo-controlled, crossover study in overweight/obese individuals (n = 16, 44% female) with prediabetes or mild T2DM but not clinical hypercortisolism. Mifepristone (50 mg every 6 h) or placebo was administered for 9 days, followed by crossover to the other treatment arm after a washout period of 6 to 8weeks. At baseline and following each treatment, oral glucose tolerance test (OGTT) and frequently sampled intravenous glucose tolerance test (FSIVGTT) were performed. Insulin sensitivity was measured using FSIVGTT [primary outcome: insulin sensitivity index (SI)] and OGTT [Matsuda index (MI) and oral glucose insulin sensitivity index (OGIS)]. Hepatic and adipose insulin resistance were assessed using hepatic insulin resistance index (HIRI), and adipose tissue insulin sensitivity index (Adipo-SI) and adipo-IR, derived from the FSIVGTT. Results Mifepristone administration did not alter whole-body glucose disposal indices of insulin sensitivity (SI, MI, and OGIS). GR blockade significantly improved Adipo-SI (61.7 ± 32.9 vs 42.8 ± 23.9; P = 0.002) and reduced adipo-IR (49.9 ± 45.9 vs 65.5 ± 43.8; P = 0.004), and HIRI (50.2 ± 38.7 vs 70.0 ± 44.3; P = 0.08). Mifepristone increased insulin clearance but did not affect insulin secretion or β-cell glucose sensitivity. Conclusion Short-term mifepristone administration improves adipose and hepatic insulin sensitivity among obese individuals with hyperglycemia without hypercortisolism.


2010 ◽  
Vol 138 (5) ◽  
pp. S-754 ◽  
Author(s):  
Nicholas Stylopoulos ◽  
Xiao B. Zhang ◽  
Anna-Liisa Brownell ◽  
Lee M. Kaplan

2007 ◽  
Vol 27 (1) ◽  
pp. 13-17 ◽  
Author(s):  
Yıldız Dallar ◽  
Dilek Dilli ◽  
Ilknur Bostancı ◽  
Elmas Öğüş ◽  
Şeyda Doğankoç ◽  
...  

2018 ◽  
Vol 19 (4) ◽  
pp. 1095 ◽  
Author(s):  
Jingyi Cao ◽  
Qi Zhu ◽  
Lin Liu ◽  
Bradley Glazier ◽  
Benjamin Hinkel ◽  
...  

2020 ◽  
Vol 4 (Supplement_2) ◽  
pp. 1703-1703
Author(s):  
Yang Yang ◽  
Xinyun Xu ◽  
Katie Graham ◽  
Ahmed Bettaieb ◽  
Christophe Morisseau ◽  
...  

Abstract Objectives Brown adipose tissue (BAT), responsible for energy expenditure through nonshivering thermogenesis, has emerged as a novel target for obesity treatment and prevention. Soluble epoxide hydrolase (sEH), encoded by Ephx2 gene, is a cytosolic enzyme that converts epoxy fatty acids (EpFAs) that are produced by cytochrome P-450 enzymes from polyunsaturated fatty acids into less active diols. Pharmacological inhibitors of sEH, such as trans-4-{4-[3-(4-trifluoromethoxyphenyl)-ureido] cyclohexyloxy} benzoic acid (t-TUCB), have been shown to be beneficial for chronic diseases by inhibiting the degradation of EpFAs. We have previously shown that t-TUCB dose-dependently promotes brown adipogenesis in vitro. This study investigated the therapeutic effects of t-TUCB on BAT activation in diet-induced obese mice. Methods Male C57BL6/J mice were fed a high-fat diet (60% kcal from fat) for 8 weeks followed by random assignment into either the control or t-TUCB group (n = 10 per group) to receive either the vehicle control or t-TUCB (3 mg/kg/day) via osmotic minipump delivery at the subcutaneous area near the interscapular BAT for 6 weeks. Bodyweight and food intake, glucose and insulin tolerance tests, cold tolerance tests, and indirect calorimetry were measured before the mice were euthanized for further biochemical analysis. Results sEH inhibition by t-TUCB in the obese mice did not change body weight, fat pad weight, food intake, fasting blood glucose, glucose and insulin tolerance, or cold tolerance, but significantly decreased blood triglyceride levels and increased heat production during both day and night. Moreover, t-TUCB significantly increased protein expression of brown marker gene PGC-1alpha and lipid droplet-associated protein perilipin (PLIN), but not uncoupling protein 1 (UCP1), in the interscapular BAT of diet-induced obese mice. Conclusions Our results suggest that sEH pharmacological inhibition may be beneficial for BAT activation by increasing mitochondrial biogenesis and lipolysis in the BAT. Further studies using the sEH inhibitors and/or EpFA generating diets for obesity treatment and prevention are warranted. Funding Sources The work was supported by NIH 1R15DK114790–01A1 (to L.Z.), K99DK100736 and R00DK100736 (to A.B.), R15AT008733 (to S.W.), R35 ES030443 and P42ES004699 (to B.D.H).


Foods ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 1494
Author(s):  
Garam Yang ◽  
Eunjeong Hong ◽  
Sejong Oh ◽  
Eungseok Kim

In this study, the role of non-viable Lactobacillus johnsonii JNU3402 (NV-LJ3402) in diet-induced obesity was investigated in mice fed a high-fat diet (HFD). To determine whether NV-LJ3402 exhibits a protective effect against diet-induced obesity, 7-week-old male C57BL/6J mice were fed a normal diet, an HFD, or an HFD with NV-LJ3402 for 14 weeks. NV-LJ3402 administration was associated with a significant reduction in body weight gain and in liver, epididymal, and inguinal white adipose tissue (WAT) and brown adipose tissue weight in HFD-fed mice. Concomitantly, NV-LJ3402 administration to HFD-fed mice also decreased the triglyceride levels in the plasma and metabolic tissues and slightly improved insulin resistance. Furthermore, NV-LJ3402 enhanced gene programming for energy dissipation in the WATs of HFD-fed mice as well as in 3T3-L1 adipocytes with increased peroxisome proliferator-activated receptor-γ (PPARγ) transcriptional activity, suggesting that the PPARγ pathway plays a key role in mediating the anti-obesity effect of NV-LJ3402 in HFD-fed mice. Furthermore, NV-LJ3402 administration in HFD-fed mice enhanced mitochondrial levels and function in WATs and also increased the body temperature upon cold exposure. Together, these results suggest that NV-LJ3402 could be safely used to develop dairy products that ameliorate diet-induced obesity and hyperlipidemia.


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