scholarly journals Apelin, an APJ Receptor Ligand, Regulates Body Adiposity and Favors the Messenger Ribonucleic Acid Expression of Uncoupling Proteins in Mice

Endocrinology ◽  
2007 ◽  
Vol 148 (6) ◽  
pp. 2690-2697 ◽  
Author(s):  
Keiko Higuchi ◽  
Takayuki Masaki ◽  
Koro Gotoh ◽  
Seiichi Chiba ◽  
Isao Katsuragi ◽  
...  

Apelin, the endogenous ligand of the APJ receptor, has been identified in a variety of tissues, including stomach, heart, skeletal muscle, and white adipose tissue. We sought to clarify the effects of apelin on body adiposity and the expression of uncoupling proteins (UCPs) in C57BL/6 mice. Treatment with ip apelin at a dose of 0.1 μmol/kg·d for 14 d decreased the weight of white adipose tissue and serum levels of insulin and triglycerides, compared with controls, without influencing food intake. Apelin treatment also decreased body adiposity and serum levels of insulin and triglycerides in obese mice fed a high-fat diet. Apelin increased the serum adiponectin level and decreased that of leptin. Additionally, apelin treatment increased mRNA expression of UCP1, a marker of peripheral energy expenditure, in brown adipose tissue (BAT) and of UCP3, a regulator of fatty acid export, in skeletal muscle. In addition, immunoblot bands and relative densities of UCP1 content in BAT were also higher in the apelin group than controls. Furthermore, apelin treatment increased body temperature and O2 consumption and decreased the respiratory quotient. In conclusion, apelin appears to regulate adiposity and lipid metabolism in both lean and obese mice. In addition, apelin regulates insulin resistance by influencing the circulating adiponectin level, the expression of BAT UCP1, and energy expenditure in mice.

Nutrients ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1347 ◽  
Author(s):  
Ri Ryu ◽  
Eun-Young Kwon ◽  
Ji-Young Choi ◽  
Jong Cheol Shon ◽  
Kwang-Hyeon Liu ◽  
...  

This study aimed to elucidate the molecular mechanism of Chrysanthemum morifolium Ramat. against obesity and diabetes, by comparing the transcriptional changes in epididymal white adipose tissue (eWAT) with those of the bioactive compound in C. morifolium, luteolin (LU). Male C57BL/6J mice were fed a normal diet, high-fat diet (HFD), and HFD supplemented with 1.5% w/w chrysanthemum leaf ethanol extract (CLE) for 16 weeks. Supplementation with CLE and LU significantly decreased the body weight gain and eWAT weight by stimulating mRNA expressions for thermogenesis and energy expenditure in eWAT via lipid mobilization, which may be linked to the attenuation of dyslipidemia. Furthermore, CLE and LU increased uncoupling protein-1 protein expression in brown adipose tissue, leading to energy expenditure. Of note, CLE and LU supplements enhanced the balance between lipid storage and mobilization in white adipose tissue (WAT), in turn, inhibiting adipocyte inflammation and lipotoxicity of peripheral tissues. Moreover, CLE and LU attenuated hepatic steatosis by suppressing hepatic lipogenesis, thereby ameliorating insulin resistance and dyslipidemia. Our data suggest that CLE helps inhibit obesity and its comorbidities via the complex interplay between liver and WAT in diet-induced obese mice.


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

2003 ◽  
Vol 95 (6) ◽  
pp. 2408-2415 ◽  
Author(s):  
Yoriko Masuda ◽  
Satoshi Haramizu ◽  
Kasumi Oki ◽  
Koichiro Ohnuki ◽  
Tatsuo Watanabe ◽  
...  

Capsiate is a nonpungent capsaicin analog, a recently identified principle of the nonpungent red pepper cultivar CH-19 Sweet. In the present study, we report that 2-wk treatment of capsiate increased metabolic rate and promoted fat oxidation at rest, suggesting that capsiate may prevent obesity. To explain these effects, at least in part, we examined uncoupling proteins (UCPs) and thyroid hormones. UCPs and thyroid hormones play important roles in energy expenditure, the maintenance of body weight, and thermoregulation. Two-week treatment of capsiate increased the levels of UCP1 protein and mRNA in brown adipose tissue and UCP2 mRNA in white adipose tissue. This dose of capsiate did not change serum triiodothyronine or thyroxine levels. A single dose of capsiate temporarily raised both UCP1 mRNA in brown adipose tissue and UCP3 mRNA in skeletal muscle. These results suggest that UCP1 and UCP2 may contribute to the promotion of energy metabolism by capsiate, but that thyroid hormones do not.


2015 ◽  
Vol 112 (45) ◽  
pp. 14006-14011 ◽  
Author(s):  
Yifei Miao ◽  
Wanfu Wu ◽  
Yubing Dai ◽  
Laure Maneix ◽  
Bo Huang ◽  
...  

The recent discovery of browning of white adipose tissue (WAT) has raised great research interest because of its significant potential in counteracting obesity and type 2 diabetes. Browning is the result of the induction in WAT of a newly discovered type of adipocyte, the beige cell. When mice are exposed to cold or several kinds of hormones or treatments with chemicals, specific depots of WAT undergo a browning process, characterized by highly activated mitochondria and increased heat production and energy expenditure. However, the mechanisms underlying browning are still poorly understood. Liver X receptors (LXRs) are one class of nuclear receptors, which play a vital role in regulating cholesterol, triglyceride, and glucose metabolism. Following our previous finding that LXRs serve as repressors of uncoupling protein-1 (UCP1) in classic brown adipose tissue in female mice, we found that LXRs, especially LXRβ, also repress the browning process of subcutaneous adipose tissue (SAT) in male rodents fed a normal diet. Depletion of LXRs activated thyroid-stimulating hormone (TSH)-releasing hormone (TRH)-positive neurons in the paraventricular nucleus area of the hypothalamus and thus stimulated secretion of TSH from the pituitary. Consequently, production of thyroid hormones in the thyroid gland and circulating thyroid hormone level were increased. Moreover, the activity of thyroid signaling in SAT was markedly increased. Together, our findings have uncovered the basis of increased energy expenditure in male LXR knockout mice and provided support for targeting LXRs in treatment of obesity.


2018 ◽  
Vol 22 (2) ◽  
pp. 265-272 ◽  
Author(s):  
Y. V. Piskunova ◽  
A. Y. Kazantceva ◽  
A. V. Baklanov ◽  
N. M. Bazhan

The lethal yellow mutation in agouti loci (Ay mutation) reduces the activity of melanocortin (MC) receptors and causes hyperphagia, obesity and type two diabetes mellitus in aging mice (Ay mice). It is unknown if changes in distinct elements of the metabolic system such as white adipose tissue (WAT) and brown adipose tissue (BAT), and skeletal muscle will manifest before the development of obesity. The aim of this work was to measure the relative gene expression of key proteins that regulate carbohydrate-lipid metabolism in WAT, BAT and skeletal muscle in Ay mice before the development of obesity. C57Bl/6J mice bearing a dominant autosomal mutation Ay (Ay /a mice) and mice of the standard genotype (a/a mice, control) have been studied in three age groups: 10, 15 and 30 weeks. The relative mRNA level of genes was measured by real-time PCR in skeletal muscles (uncoupling protein 3 (Ucp3) and carnitine palmitoyl transferase 1b (Cpt1b) (free fatty acids oxidation), solute carrier family 2 (facilitated glucose transporter), member 4 (Slc2a4) (glucose uptake)), in WAT lipoprotein lipase (Lpl) (triglyceride deposition), hormone-sensitive lipase (Lipe) (lipid mobilization), and Slc2a4 (glucose uptake)), and in BAT: uncoupling protein 1 (Ucp1) (energy expenditure). The expression of Cpt1b was reduced in young Ay mice (10 weeks), there was no transient peak of transcription of Cpt1b, Ucp3 in skeletal muscle tissue and Lipe, Slc2a4 in WAT in early adult Ay mice (15 weeks), which was noted in а/а mice. Reduction of the transcriptional activity of the studied genes in skeletal muscle and white adipose tissue can initiate the development of melanocortin obesity in Ay mice.


2020 ◽  
Vol 319 (3) ◽  
pp. E529-E539
Author(s):  
Jose Diego Botezelli ◽  
Peter Overby ◽  
Lorenzo Lindo ◽  
Su Wang ◽  
Obélia Haïda ◽  
...  

Hyperinsulinemia plays a causal role in adipose tissue expansion. Mice with reduced insulin have increased energy expenditure, but the mechanisms remained unclear. Here we investigated the effects of genetically reducing insulin production on uncoupling and oxidative mitochondrial proteins in liver, skeletal muscle, white adipose tissue (WAT), and brown adipose tissue (BAT). Male Ins1+/+ or Ins1+/− littermates were fed either a low-fat diet (LFD) or a high-fat diet (HFD) for 4 wk, starting at 8 wk of age. Replicating our previous observations, HFD increased fasting hyperinsulinemia, and Ins1+/− mice had significantly lower circulating insulin compared with Ins1+/+ littermates. Fasting glucose and body weight were not different between genotypes. We did not observe robust significant differences in liver or skeletal muscle. In mesenteric WAT, Ins1+/− mice had reduced Ndufb8 and Sdhb, while Ucp1 was increased in the context of HFD. HFD alone had a dramatic inhibitory effect on Pparg abundance. In inguinal WAT, Ins1+/− mice exhibited significant increases in oxidative complex proteins, independent of diet, without affecting Ucp1, Pparg, or Prdm16:Pparg association. In BAT, lowered insulin increased Sdhb protein levels that had been reduced by HFD. Ucp1 protein, Prdm16:Pparg association, and Sirt3 abundance were all increased in the absence of diet-induced hyperinsulinemia. Our data show that reducing insulin upregulates oxidative proteins in inguinal WAT without affecting Ucp1, whereas in mesenteric WAT and BAT, reducing insulin upregulates Ucp1 in the context of HFD. Preventing hyperinsulinemia has early depot-specific effects on adipose tissue metabolism and helps explain the increased energy expenditure previously reported in Ins1+/− mice.


2020 ◽  
Vol 4 (Supplement_2) ◽  
pp. 1603-1603
Author(s):  
Mehrnaz Abbasi ◽  
Shu Wang

Abstract Objectives Obesity and its comorbidities are major public health problems worldwide. The transformation of white adipose tissue (WAT) to brown adipose tissue (BAT); browning of WAT, may serve as a promising strategy for combating obesity. Metformin is not only the first line of drug for type 2 diabetes but also has an anti-obesity potential. Emerging evidence suggests that metformin can reduce body weight and enhance energy expenditure via activating BAT or browning of WAT. However, metformin delivery to adipose tissue is limited due to the lack of adipocyte-specific surface markers. Thus, the direct injection might be an alternative. Methods ApoE3-Leiden.human cholesteryl ester transfer protein (E3L.CETP) mice (5 mice/group) were fed a high-fat diet (HFD) for 15 weeks. From week 10 to 15, mice were randomly divided into 3 groups as 1. Metformin inguinal WAT (IgWAT) injection, 2. Metformin delivery to interscapular BAT (IBAT) and 3. Saline IgWAT injection (HFD control). Mice received injections twice per week (40 mg/kg/week). Bodyweight (BW), body composition, food intake, energy expenditure and glucose tolerance test (GTT) were measured. Gene expression of beige or brown makers was analyzed using real time-PCR. Results Compared to HFD control mice, IgWAT- and IBAT-treated mice lost 2.16% and 1.9% more of their body fat, respectively (P-value < 0.001). IgWAT- and IBAT-treated mice had 1.09- and 1.24-fold lower area under the curve calculated from the GTT time course than HFD control mice, respectively, but the differences were not statistically significant. The metabolic cage data indicated that both IgWAT- and IBAT-treated mice compared to HFD control mice had significantly decreased respiration exchange ratio (RER) (P < 0.0001). IgWAT-treated mice had significantly lower IgWAT weight than the HFD control mice (P < 0.05). IgWAT-treated compared to HFD control mice had 1.5-, 2-, 2.7- and 3-fold higher expression of UCP1, PRDM16, TMEM26 and Elovl3 in IgWAT, respectively. Conclusions This study demonstrated that local delivery of metformin to IgWAT and IBAT decreased BW and fat mass, which were associated with reduced RER and improved glucose homeostasis. Direct delivery of metformin to IgWAT and IBAT might be an efficient approach for combating obesity via inducing IgWAT browning and enhancing IBAT activity. Funding Sources NIH 1R15AT010395 and AHA 19AIREA34480011.


1993 ◽  
Vol 265 (5) ◽  
pp. E743-E751
Author(s):  
C. Chen ◽  
P. F. Williams ◽  
I. D. Caterson

Glycogen metabolism in the liver, skeletal muscle, cardiac muscle, and white adipose tissue was studied in gold thioglucose (GTG) obese mice after fasting and during refeeding. Prolonged (48 h) fasted control and GTG mice were refed with standard laboratory diet for 24 h. During fasting and refeeding, the changes in glycogen content and the activity of glycogen synthase I and R and phosphorylase alpha in the liver were similar in lean and GTG mice. However, the glycogen storage in the livers from GTG mice was always greater than that in lean animals. In GTG mice the activity of liver glycogen synthase I and R was significantly higher than that in lean animals 3 and 6 h after refeeding. The activity of liver phosphorylase alpha in GTG mice was higher than that in lean mice after refeeding. There were no significant differences in the glycogen content of white adipose tissue, cardiac muscle, and skeletal muscle from lean and GTG mice during the entire study. The results of this study suggest that increased glycogen storage in the liver is a major alteration in nonoxidative glucose metabolism and contributes to the development of insulin resistance and glucose intolerance in GTG obese mice.


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