scholarly journals Low-dose UV radiation before running wheel access activates brown adipose tissue

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.

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 ◽  
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.


2011 ◽  
Vol 300 (6) ◽  
pp. R1459-R1467 ◽  
Author(s):  
Pei-Ting Chao ◽  
Chantelle E. Terrillion ◽  
Timothy H. Moran ◽  
Sheng Bi

We have previously demonstrated that running-wheel access normalizes the food intake and body weight of Otsuka Long-Evens Tokushima Fatty (OLETF) rats. Following 6 wk of running-wheel access beginning at 8 wk of age, the body weight of OLETF rats remains reduced, demonstrating a lasting effect on their phenotype. In contrast, access to a high-fat diet exacerbates the hyperphagia and obesity of OLETF rats. To determine whether diet modulates the long-term effects of exercise, we examined the effects of high-fat diet on food intake and body weight in OLETF rats that had prior access to running wheels for 4 wk. We found that 4 wk of running exercise significantly decreased food intake and body weight of OLETF rats. Consistent with prior results, 4 wk of exercise also produced long-lasting effects on food intake and body weight in OLETF rats fed a regular chow. When running wheels were relocked, OLETF rats stabilized at lower levels of body weight than sedentary OLETF rats. However, access to a high-fat diet offset these effects. When OLETF rats were switched to a high-fat diet following wheel relocking, they significantly increased food intake and body weight, so that they reached levels similar to those of sedentary OLETF rats fed a high-fat diet. Gene expression determination of hypothalamic neuropeptides revealed changes that appeared to be appropriate responses to the effects of diet and running exercise. Together, these results demonstrate that high-fat diet modulates the long-lasting effects of exercise on food intake and body weight in OLETF rats.


2020 ◽  
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.


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.


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.


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.


2009 ◽  
Vol 297 (1) ◽  
pp. E184-E193 ◽  
Author(s):  
Josep Mercader ◽  
Joan Ribot ◽  
Incoronata Murano ◽  
Søren Feddersen ◽  
Saverio Cinti ◽  
...  

Brown adipose tissue activity dissipates energy as heat, and there is evidence that lack of the retinoblastoma protein (pRb) may favor the development of the brown adipocyte phenotype in adipose cells. In this work we assessed the impact of germ line haploinsufficiency of the pRb gene (Rb) on the response to high-fat diet feeding in mice. Rb+/− mice had body weight and adiposity indistinguishable from that of wild-type (Rb+/+) littermates when maintained on a standard diet, yet they gained less body weight and body fat after long-term high-fat diet feeding coupled with reduced feed efficiency and increased rectal temperature. Rb haploinsufficiency ameliorated insulin resistance and hepatosteatosis after high-fat diet in male mice, in which these disturbances were more marked than in females. Compared with wild-type littermates, Rb+/− mice fed a high-fat diet displayed higher expression of peroxisome proliferator-activated receptor (PPAR)γ as well as of genes involved in mitochondrial function, cAMP sensitivity, brown adipocyte determination, and tissue vascularization in white adipose tissue depots. Furthermore, Rb+/− mice exhibited signs of enhanced activation of brown adipose tissue and higher expression levels of PPARα in liver and of PPARδ in skeletal muscle, suggestive of an increased capability for fatty acid oxidation in these tissues. These findings support a role for pRb in modulating whole body energy metabolism and the plasticity of the adipose tissues in vivo and constitute first evidence that partial deficiency in the Rb gene protects against the development of obesity and associated metabolic disturbances.


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