scholarly journals Single Head-Neck Irradiation Intervention Increases Thyroid Hormone Level and Enhances Energy Metabolism in High-Fat Diet Mice

Author(s):  
Qian Lin ◽  
Caishun Zhang ◽  
Manwen Li ◽  
Haidan Wang ◽  
Kaizhen Su ◽  
...  

Abstract Radiotherapy, an established treatment of malignant diseases of the head and neck, increases the risk of chronic metabolic disorders. However, the molecular mechanisms responsible for metabolic dysfunction after irradiation remain unknown. We aimed to determine whether single head-neck irradiation intervention changes the levels of thyroid hormones and affects energy metabolism in high-fat diet mice and in chow diet mice. C57BL/6 mice were treated with a single dose of 6 Gy X-ray head-neck irradiation and were fed a high-fat diet. Body weight, accumulated food intake, fasting blood glucose and glucose tolerance were measured during the study. Plasma, brown adipose tissue, thyroid, liver and white adipose tissue were collected for histological analysis. We found that head-neck irradiation significantly increased food intake and decreased body weight in high-fat diet mice. However, there were no obvious changes in chow diet mice. Further studies showed that head-neck irradiation significantly increased levels of 3,5,3’-triiodothyronine and thyroid-stimulating hormone, as well as expression of uncoupling protein 1 in brown adipose tissue and glucose transporter 2 in liver in high-fat diet mice. Our results suggest that single head-neck irradiation intervention increases thyroid hormones levels and enhances energy metabolism in high-fat diet mice.

1984 ◽  
Vol 246 (6) ◽  
pp. R943-R948 ◽  
Author(s):  
J. Oku ◽  
G. A. Bray ◽  
J. S. Fisler ◽  
R. Schemmel

The effects of ventromedial hypothalamic (VMH) knife-cut lesions on food intake and body weight of S 5B/Pl rats, which are normally resistant to obesity when eating a high-fat diet, were examined in two experiments. In the first experiment body weight increased only slightly after VMH knife-cut lesions when animals were fed pelleted laboratory chow or a 10% corn oil diet. When eating the 30% corn oil diet, however, body weight increased in the VMH knife-cut rats. In the second experiment VMH knife-cut lesions produced a small weight gain in rats fed the 10% fat diet; this manipulation also increased food intake and disrupted the normal diurnal feeding pattern. Changes in the weight of the liver, interscapular brown adipose tissue, and white adipose tissue paralleled the changes in body weight. Plasma insulin increased in the rats eating the 30% corn oil diet ad libitum but not in the VMH-lesioned animals pair fed to the sham-operated rats. Incorporation of 3H from 3H2O into lipid was significantly increased in white fat of animals with VMH knife cuts. Similar results were obtained from incubation of adipose tissue in vitro with insulin and radioactively labeled glucose. These studies show that hypothalamic knife-cut lesions can remove the resistance of the S 5B/Pl rats to obesity when they are fed a high-fat diet.


Endocrinology ◽  
2016 ◽  
Vol 157 (4) ◽  
pp. 1457-1466 ◽  
Author(s):  
Miyuki Shibata ◽  
Ryoichi Banno ◽  
Mariko Sugiyama ◽  
Takashi Tominaga ◽  
Takeshi Onoue ◽  
...  

Abstract Agouti-related protein (AgRP) expressed in the arcuate nucleus is a potent orexigenic neuropeptide, which increases food intake and reduces energy expenditure resulting in increases in body weight (BW). Glucocorticoids, key hormones that regulate energy balance, have been shown in rodents to regulate the expression of AgRP. In this study, we generated AgRP-specific glucocorticoid receptor (GR)-deficient (knockout [KO]) mice. Female and male KO mice on a high-fat diet (HFD) showed decreases in BW at the age of 6 weeks compared with wild-type mice, and the differences remained significant until 16 weeks old. The degree of resistance to diet-induced obesity was more robust in female than in male mice. On a chow diet, the female KO mice showed slightly but significantly attenuated weight gain compared with wild-type mice after 11 weeks, whereas there were no significant differences in BW in males between genotypes. Visceral fat pad mass was significantly decreased in female KO mice on HFD, whereas there were no significant differences in lean body mass between genotypes. Although food intake was similar between genotypes, oxygen consumption was significantly increased in female KO mice on HFD. In addition, the uncoupling protein-1 expression in the brown adipose tissues was increased in KO mice. These data demonstrate that the absence of GR signaling in AgRP neurons resulted in increases in energy expenditure accompanied by decreases in adiposity in mice fed HFD, indicating that GR signaling in AgRP neurons suppresses energy expenditure under HFD conditions.


Endocrinology ◽  
2014 ◽  
Vol 156 (2) ◽  
pp. 411-418 ◽  
Author(s):  
Pierre Cardinal ◽  
Luigi Bellocchio ◽  
Omar Guzmán-Quevedo ◽  
Caroline André ◽  
Samantha Clark ◽  
...  

The paraventricular nucleus of the hypothalamus (PVN) regulates energy balance by modulating not only food intake, but also energy expenditure (EE) and brown adipose tissue thermogenesis. To test the hypothesis that cannabinoid type 1 (CB1) receptor in PVN neurons might control these processes, we used the Cre/loxP system to delete CB1 from single-minded 1 (Sim1) neurons, which account for the majority of PVN neurons. On standard chow, mice lacking CB1 receptor in Sim1 neurons (Sim1-CB1-knockout [KO]) had food intake, body weight, adiposity, glucose metabolism, and EE comparable with wild-type (WT) (Sim1-CB1-WT) littermates. However, maintenance on a high-fat diet revealed a gene-by-diet interaction whereby Sim1-CB1-KO mice had decreased adiposity, improved insulin sensitivity, and increased EE, whereas feeding behavior was similar to Sim1-CB1-WT mice. Additionally, high-fat diet-fed Sim1-CB1-KO mice had increased mRNA expression of the β3-adrenergic receptor, as well as of uncoupling protein-1, cytochrome-c oxidase subunit IV and mitochondrial transcription factor A in the brown adipose tissue, all molecular changes suggestive of increased thermogenesis. Pharmacological studies using β-blockers suggested that modulation of β-adrenergic transmission play an important role in determining EE changes observed in Sim1-CB1-KO. Finally, chemical sympathectomy abolished the obesity-resistant phenotype of Sim1-CB1-KO mice. Altogether, these findings reveal a diet-dependent dissociation in the CB1 receptor control of food intake and EE, likely mediated by the PVN, where CB1 receptors on Sim1-positive neurons do not impact food intake but hinder EE during dietary environmental challenges that promote body weight gain.


2020 ◽  
Vol 244 (3) ◽  
pp. 473-486 ◽  
Author(s):  
Tristan S Allemann ◽  
Gursimran K Dhamrait ◽  
Naomi J Fleury ◽  
Tamara N Abel ◽  
Prue H Hart ◽  
...  

In previous preclinical studies, low (non-burning) doses of UV radiation (UVR) limited weight gain and metabolic dysfunction in mice fed with a high-fat diet. Here, we explored the effects of low-dose UVR on physical activity and food intake and mechanistic pathways in interscapular brown adipose tissue (iBAT). Young adult C57Bl/6J male mice, housed as individuals, were fed a high-fat diet and exposed to low-dose UVR (sub-oedemal, 1 kJ/m2 UVB, twice-a-week) or ‘mock’ treatment, with or without running wheel access (2 h, for ‘moderate’ physical activity) immediately after phototherapy. There was no difference in distance run in mice exposed to UVR or mock-treated over 12 weeks of exposure to running wheels (P = 0.14). UVR (alone) did not significantly affect food intake, adiposity, or signs of glucose dysfunction. Access to running wheels increased food intake (after 10 weeks, P ≤ 0.02) and reduced gonadal white adipose tissue and iBAT mass (P ≤ 0.03). Body weight and hepatic steatosis were lowest in mice exposed to UVR with running wheel access. In the iBAT of mice exposed to UVR and running wheels, elevated Atgl, Cd36, Fasn, Igf1, Pparγ, and Ucp1 mRNAs and reduced CD11c on F4-80 + MHC class II+ macrophages were observed, while renal Sglt2 mRNA levels were increased, compared to high-fat diet alone (P ≤ 0.03). Blood levels of 25-hydroxyvitamin D were not increased by exposure to UVR and/or access to running wheels. In conclusion, when combined with physical activity, low-dose UVR may more effectively limit adiposity (specifically, body weight and hepatic steatosis) and modulate metabolic and immune pathways in iBAT.


2021 ◽  
Vol 22 (10) ◽  
pp. 5390
Author(s):  
Qianhui Zeng ◽  
Nannan Wang ◽  
Yaru Zhang ◽  
Yuxuan Yang ◽  
Shuangshuang Li ◽  
...  

Obesity-induced adipose tissue dysfunction and disorders of glycolipid metabolism have become a worldwide research priority. Zfp217 plays a crucial role in adipogenesis of 3T3-L1 preadipocytes, but about its functions in animal models are not yet clear. To explore the role of Zfp217 in high-fat diet (HFD)-induced obese mice, global Zfp217 heterozygous knockout (Zfp217+/−) mice were constructed. Zfp217+/− mice and Zfp217+/+ mice fed a normal chow diet (NC) did not differ significantly in weight gain, percent body fat mass, glucose tolerance, or insulin sensitivity. When challenged with HFD, Zfp217+/− mice had less weight gain than Zfp217+/+ mice. Histological observations revealed that Zfp217+/− mice fed a high-fat diet had much smaller white adipocytes in inguinal white adipose tissue (iWAT). Zfp217+/− mice had improved metabolic profiles, including improved glucose tolerance, enhanced insulin sensitivity, and increased energy expenditure compared to the Zfp217+/+ mice under HFD. We found that adipogenesis-related genes were increased and metabolic thermogenesis-related genes were decreased in the iWAT of HFD-fed Zfp217+/+ mice compared to Zfp217+/− mice. In addition, adipogenesis was markedly reduced in mouse embryonic fibroblasts (MEFs) from Zfp217-deleted mice. Together, these data indicate that Zfp217 is a regulator of energy metabolism and it is likely to provide novel insight into treatment for obesity.


Foods ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 688 ◽  
Author(s):  
Kyoung Soo Kim ◽  
Hari Madhuri Doss ◽  
Hee-Jin Kim ◽  
Hyung-In Yang

This study was conducted to investigate if taurine supplementation stimulates the induction of thermogenic genes in fat tissues and muscles and decipher the mechanism by which taurine exerts its anti-obesity effect in a mildly obese ICR (CD-1®) mouse model. Three groups of ICR mice were fed a normal chow diet, a high-fat diet (HFD), or HFD supplemented with 2% taurine in drinking water for 28 weeks. The expression profiles of various genes were analyzed by real time PCR in interscapular brown adipose tissue (BAT), inguinal white adipose tissue (iWAT), and the quadriceps muscles of the experimental groups. Genes that are known to regulate thermogenesis like PGC-1α, UCP-1, Cox7a1, Cox8b, CIDE-A, and β1-, β2-, and β3-adrenergic receptors (β-ARs) were found to be differentially expressed in the three tissues. These genes were expressed at a very low level in iWAT as compared to BAT and muscle. Whereas, HFD increased the expression of these genes. Taurine supplementation stimulated the expression of UCP-1, Cox7a1, and Cox8b in BAT and only Cox7a1 in muscle, while there was a decrease in iWAT. In contrast, fat deposition-related genes, monoamine oxidases (MAO)-A, and -B, and lipin-1, were decreased by taurine supplementation only in iWAT and not in BAT or muscle. In conclusion, the potential anti-obesity effects of taurine may be partly due to upregulated thermogenesis in BAT, energy metabolism of muscle, and downregulated fat deposition in iWAT.


2005 ◽  
Vol 288 (6) ◽  
pp. E1236-E1243 ◽  
Author(s):  
Elena Velkoska ◽  
Timothy J. Cole ◽  
Margaret J. Morris

Early life nutrition impacts on subsequent risk of obesity and hypertension. Several brain chemicals responsible for both feeding and cardiovascular regulation are altered in obesity. We examined effects of early postnatal overnutrition on blood pressure, brain neuropeptide Y (NPY), and adiposity markers. Rat pup litters were adjusted to either 3 or 12 male animals (overnutrition and control, respectively) on day 1 of life. After weaning, rats were given either a palatable high-fat diet or standard chow. Smaller litter pups were significantly heavier by 17 days of age. By 16 wk, the effect of litter size was masked by that of diet, postweaning. Small and normal litter animals fed a high-fat diet had similar increases in body weight, plasma insulin, leptin, and adiponectin concentrations, leptin mRNA, and fat masses relative to chow-fed animals. An increase in 11β-hydroxysteroid dehydrogenase-1 mRNA in white adipose tissue, and a decrease in uncoupling protein-1 mRNA in brown adipose tissue in both small litter groups at 16 wk of age, may represent a programming effect of the altered litter size. NPY concentration in the paraventricular nucleus of the hypothalamus was reduced in high fat-fed groups. Blood pressure was significantly elevated at 13 wk in high-fat-fed animals. This study demonstrates that overnourishment during early postnatal development leads to profound changes in body weight at weaning, which tended to abate with maturation. Thus the effects of long-term dietary intervention postweaning can override those of litter size-induced obesity.


2010 ◽  
Vol 299 (6) ◽  
pp. R1423-R1439 ◽  
Author(s):  
Mihai Covasa

The gastrointestinal tract serves as a portal sensing incoming nutrients and relays mechanical and chemosensory signals of a meal to higher brain centers. Prolonged consumption of dietary fat causes adaptive changes within the alimentary, metabolic, and humoral systems that promote a more efficient process for energy metabolism from this rich source, leading to storage of energy in the form of adipose tissue. Furthermore, prolonged ingestion of dietary fats exerts profound effects on responses to signals involved in termination of a meal. This article reviews the effects of ingested fat on gastrointestinal motility, hormone release, and neuronal substrates. It focuses on changes in sensitivity to satiation signals resulting from chronic ingestion of high-fat diet, which may lead to disordered appetite and dysregulation of body weight.


2021 ◽  
Vol 5 (Supplement_2) ◽  
pp. 1260-1260
Author(s):  
Yang Yang ◽  
Xinyun Xu ◽  
Christophe Morisseau ◽  
Bruce Hammock ◽  
Ahmed Bettaieb ◽  
...  

Abstract Objectives Brown adipose tissue (BAT) is a promising target for obesity prevention. N-3 epoxides are fatty acid epoxides produced from n-3 polyunsaturated fatty acids and shown to be beneficial for health. However, these epoxides are unstable and quickly metabolized by the cytosolic soluble epoxide hydrolase (sEH). Here, we investigated the effects of sEH inhibitor (t-TUCB) alone or combined with two different n-3 epoxides on BAT activation in the development of diet-induced obesity and associated metabolic disorders. Methods Male C57BL6/J mice were fed a high-fat diet and received either of the following treatment: the vehicle control, t-TUCB alone (T), or t-TUCB combined with 19,20-EDP (T + EDP) or 17,18-EEQ (T + EEQ) via osmotic minipump delivery near the interscapular BAT for 6 weeks. Mice were examined for changes in body weight, food intake, glucose, insulin, and cold tolerance tests, and indirect calorimetry. Blood and tissue biochemical analyses were also performed to assess changes in metabolic homeostasis. Results Although no differences in food intake were observed, there were small but significant increases in body weight in both T and T + EDP groups. Mice in the T + EDP and T + EEQ groups showed significant decreases in fasting glucose and serum TG levels, higher core body temperature, and better cold tolerance compared to the controls. However, heat production was significantly increased only in the T + EEQ group. Thermogenic UCP1 protein expression showed a moderate, but not significant, increase in the T + EEQ group. On the other hand, PGC1 α protein expression was significantly increased in the T, T + EDP, and T + EEQ groups compared to the controls. Perilipin protein expression and phosphorylation were also significantly increased in the three treated groups. In contrast, protein expression of FABP4 and HSL was only increased in the T and T + EDP groups, and CD36 protein expression was only increased in the T + EEQ group. Conclusions Our results suggest that sEH pharmacological inhibition by t-TUCB combined with n-3 epoxides may prevent high-fat diet-induced glucose and lipid disorders, in part through increased thermogenesis and upregulating of protein expression of thermogenic and lipid metabolic genes. Funding Sources The work was supported by NIH grants to L.Z., A.B., and B.D.H.


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