scholarly journals SIM1 Overexpression Partially Rescues Agouti Yellow and Diet-Induced Obesity by Normalizing Food Intake

Endocrinology ◽  
2006 ◽  
Vol 147 (10) ◽  
pp. 4542-4549 ◽  
Author(s):  
Bassil M. Kublaoui ◽  
J. Lloyd Holder ◽  
Kristen P. Tolson ◽  
Terry Gemelli ◽  
Andrew R. Zinn

Single-minded 1 (SIM1) mutations are associated with obesity in mice and humans. Haploinsufficiency of mouse Sim1 causes hyperphagic obesity with increased linear growth and enhanced sensitivity to a high-fat diet, a phenotype similar to that of agouti yellow and melanocortin 4 receptor knockout mice. To investigate the effects of increased Sim1 dosage, we generated transgenic mice that overexpress human SIM1 and examined their phenotype. Compared with wild-type mice, SIM1 transgenic mice had no obvious phenotype on a low-fat chow diet but were resistant to diet-induced obesity on a high-fat diet due to reduced food intake with no change in energy expenditure. The SIM1 transgene also completely rescued the hyperphagia and partially rescued the obesity of agouti yellow mice, in which melanocortin signaling is abrogated. Our results indicate that the melanocortin 4 receptor signals through Sim1 or its transcriptional targets in controlling food intake but not energy expenditure.

Endocrinology ◽  
2013 ◽  
Vol 154 (3) ◽  
pp. 1047-1054 ◽  
Author(s):  
Denovan P. Begg ◽  
Joram D. Mul ◽  
Min Liu ◽  
Brianne M. Reedy ◽  
David A. D'Alessio ◽  
...  

Abstract Diet-induced obesity (DIO) reduces the ability of centrally administered insulin to reduce feeding behavior and also reduces the transport of insulin from the periphery to the central nervous system (CNS). The current study was designed to determine whether reversal of high-fat DIO restores the anorexic efficacy of central insulin and whether this is accompanied by restoration of the compromised insulin transport. Adult male Long-Evans rats were initially maintained on either a low-fat chow diet (LFD) or a high-fat diet (HFD). After 22 weeks, half of the animals on the HFD were changed to the LFD, whereas the other half continued on the HFD for an additional 8 weeks, such that there were 3 groups: 1) a LFD control group (Con; n = 18), 2) a HFD-fed, DIO group (n = 17), and 3) a HFD to LFD, DIO-reversal group (DIO-rev; n = 18). The DIO reversal resulted in a significant reduction of body weight and epididymal fat weight relative to the DIO group. Acute central insulin administration (8 mU) reduced food intake and caused weight loss in Con and DIO-rev but not DIO rats. Fasting cerebrospinal fluid insulin was higher in DIO than Con animals. However, after a peripheral bolus injection of insulin, cerebrospinal fluid insulin increased in Con and DIO-rev rats but not in the DIO group. These data provide support for previous reports that DIO inhibits both the central effects of insulin and insulin's transport to the CNS. Importantly, DIO-rev restored sensitivity to the effects of central insulin on food intake and insulin transport into the CNS.


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.


2020 ◽  
Vol 4 (Supplement_2) ◽  
pp. 1844-1844
Author(s):  
Daniel Torres ◽  
Matthew Pitts ◽  
Lucia Seale ◽  
Ann Hashimoto ◽  
Katlyn An ◽  
...  

Abstract Objectives The trace element selenium (Se) is known mainly for its antioxidant properties and is critical for proper brain function. The role of Se in regulating energy metabolism, and the sexually dimorphic nature of Se functions, however, are underappreciated, and warrant increased attention. Recent work in our lab has highlighted the importance of Se utilization in hypothalamic regulation of energy metabolism. Dietary Se is incorporated into selenoproteins in the form of the unique amino acid selenocysteine (Sec). The objective of this study was to assess the role of selenoproteins in Agouti-related peptide (Agrp)-positive neurons, an orexigenic sub-population of the hypothalamus. Methods We generated mice with Agrp-Cre-driven deletion of selenocysteine tRNA (Trsp-Agrp KO mice), which is essential for Sec incorporation into selenoproteins, thus ablating selenoprotein synthesis in Agrp-positive neurons. The metabolic phenotype of Trsp-Agrp KO mice challenged with a high-fat diet was characterized via glucose tolerance test (i.p. injection) and the use of analytical chambers to measure food intake and respiratory metabolism. Prior to sacrifice, mice were challenged with leptin (i.p. injection) to assess neuronal leptin responsivity via immunohistochemistry and western blot. Brown adipose tissue (BAT) morphology and thermogenic protein expression were also analyzed. Results Female Trsp-Agrp KO mice displayed resistance to diet-induced obesity, which was accompanied by improved glucose tolerance and elevated energy expenditure levels without changes in food intake. Female Trsp-Agrp KO mice also had greater leptin sensitivity and showed signs of elevated BAT thermogenesis. Male Trsp-Agrp KO mice displayed no changes in metabolic phenotype. Conclusions Loss of selenoproteins in Agrp-positive neurons of the hypothalamus promotes energy expenditure and reduces diet-induced obesity in a sexually dimorphic manner, leading to resistance to a high-fat diet in females. Funding Sources This work was funded by grant support from the National Institute of Diabetes and Digestive and Kidney Diseases (MJB) and Ola HAWAII, a grant from the National Institute on Minority Health and Health Disparities.


2014 ◽  
Vol 9 ◽  
pp. 211-224 ◽  
Author(s):  
Jihang Chen ◽  
Hoi Shan Wong ◽  
Hoi Yan Leung ◽  
Pou Kuan Leong ◽  
Wing Man Chan ◽  
...  

2018 ◽  
Vol 19 (10) ◽  
pp. 3281 ◽  
Author(s):  
Youngmi Lee ◽  
Eun-Young Kwon ◽  
Myung-Sook Choi

Isoliquiritigenin (ILG) is a flavonoid constituent of Glycyrrhizae plants. The current study investigated the effects of ILG on diet-induced obesity and metabolic diseases. C57BL/6J mice were fed a normal diet (AIN-76 purified diet), high-fat diet (40 kcal% fat), and high-fat diet +0.02% (w/w) ILG for 16 weeks. Supplementation of ILG resulted in decreased body fat mass and plasma cholesterol level. ILG ameliorated hepatic steatosis by suppressing the expression of hepatic lipogenesis genes and hepatic triglyceride and fatty acid contents, while enhancing β-oxidation in the liver. ILG improved insulin resistance by lowering plasma glucose and insulin levels. This was also demonstrated by the intraperitoneal glucose tolerance test (IPGTT). Additionally, ILG upregulated the expression of insulin signaling-related genes in the liver and muscle. Interestingly, ILG elevated energy expenditure by increasing the expression of thermogenesis genes, which is linked to stimulated mitochondrial biogenesis and uncoupled cellular respiration in brown adipose tissue. ILG also suppressed proinflammatory cytokine levels in the plasma. These results suggest that ILG supplemented at 0.02% in the diet can ameliorate body fat mass, plasma cholesterol, non-alcoholic fatty liver disease, and insulin resistance; these effects were partly mediated by increasing energy expenditure in high-fat fed mice.


Diabetologia ◽  
2018 ◽  
Vol 61 (9) ◽  
pp. 2030-2042 ◽  
Author(s):  
Steef Kurstjens ◽  
Janna A. van Diepen ◽  
Caro Overmars-Bos ◽  
Wynand Alkema ◽  
René J. M. Bindels ◽  
...  

Author(s):  
Sarmila Nepali ◽  
Do‑Kuk Kim ◽  
Hoon‑Yeon Lee ◽  
Hyeon‑Hui Ki ◽  
Bo‑Ram Kim ◽  
...  

2019 ◽  
Vol 28 (4) ◽  
pp. 1207-1215 ◽  
Author(s):  
Denis Nchang Che ◽  
Hyun Ju Kang ◽  
Byoung Ok Cho ◽  
Jae Young Shin ◽  
Seon Il Jang

2018 ◽  
Vol 114 (suppl_1) ◽  
pp. S34-S34
Author(s):  
V Galand ◽  
N Mougenot ◽  
A Coulombe ◽  
N Suffee-Mosbah ◽  
N Doisne ◽  
...  

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