scholarly journals Hypothalamic signaling in anorexia induced by indispensable amino acid deficiency

2012 ◽  
Vol 303 (12) ◽  
pp. E1446-E1458 ◽  
Author(s):  
Xinxia Zhu ◽  
Stephanie M. Krasnow ◽  
Quinn R. Roth-Carter ◽  
Peter R. Levasseur ◽  
Theodore P. Braun ◽  
...  

Animals exhibit a rapid and sustained anorexia when fed a diet that is deficient in a single indispensable amino acid (IAA). The chemosensor for IAA deficiency resides within the anterior piriform cortex (APC). Although the cellular and molecular mechanisms by which the APC detects IAA deficiency are well established, the efferent neural pathways that reduce feeding in response to an IAA-deficient diet remain to be fully characterized. In the present work, we investigated whether 1) central melanocortin signaling is involved in IAA deficiency-induced anorexia (IAADA) and 2) IAADA engages other key appetite-regulating neuronal populations in the hypothalamus. Rats and mice that consumed a valine-deficient diet (VDD) for 2–3 wk exhibited marked reductions in food intake, body weight, fat and lean body mass, body temperature, and white adipose tissue leptin gene expression, as well as a paradoxical increase in brown adipose tissue uncoupling protein-1 mRNA. Animals consuming the VDD had altered hypothalamic gene expression, typical of starvation. Pharmacological and genetic blockade of central melanocortin signaling failed to increase long-term food intake in this model. Chronic IAA deficiency was associated with a marked upregulation of corticotropin-releasing hormone expression in the lateral hypothalamus, particularly in the parasubthalamic nucleus, an area heavily innervated by efferent projections from the APC. Our observations indicate that the hypothalamic melanocortin system plays a minor role in acute, but not chronic, IAADA and suggest that the restraint on feeding is analogous to that observed after chronic dehydration.

2014 ◽  
Vol 222 (3) ◽  
pp. 327-339 ◽  
Author(s):  
Abdoulaye Diané ◽  
Nikolina Nikolic ◽  
Alexander P Rudecki ◽  
Shannon M King ◽  
Drew J Bowie ◽  
...  

Pituitary adenylate cyclase-activating polypeptide (PACAP) is a widely distributed neuropeptide that acts as a neurotransmitter, neuromodulator, neurotropic factor, neuroprotectant, secretagogue,and neurohormone. Owing to its pleiotropic biological actions, knockout ofPacap(Adcyap1) has been shown to induce several abnormalities in mice such as impaired thermoregulation. However, the underlying physiological and molecular mechanisms remain unclear. A previous report has shown that cold-exposedPacapnull mice cannot supply appropriate levels of norepinephrine (NE) to brown adipocytes. Therefore, we hypothesized that exogenous NE would rescue the impaired thermogenic response ofPacapnull mice during cold exposure. We compared the adaptive thermogenic capacity ofPacap−/−toPacap+/+mice in response to NE when housed at room temperature (24 °C) and after a 3.5-week cold exposure (4 °C). Biochemical parameters, expression of thermogenic genes, and morphological properties of brown adipose tissue (BAT) and white adipose tissue (WAT) were also characterized. Results showed that there was a significant effect of temperature, but no effect of genotype, on the resting metabolic rate in conscious, unrestrained mice. However, the normal cold-induced increase in the basal metabolic rate and NE-induced increase in thermogenesis were severely blunted in cold-exposedPacap−/−mice. These changes were associated with altered substrate utilization, reduced β3-adrenergic receptor (β3-Ar(Adrb3)) and hormone-sensitive lipase (Hsl(Lipe)) gene expression, and increased fibroblast growth factor 2 (Fgf2) gene expression in BAT. Interestingly,Pacap−/−mice had depleted WAT depots, associated with upregulated uncoupling protein 1 expression in inguinal WATs. These results suggest that the impairment of adaptive thermogenesis inPacapnull mice cannot be rescued by exogenous NE perhaps in part due to decreased β3-Ar-mediated BAT activation.


1997 ◽  
Vol 272 (6) ◽  
pp. E1031-E1036 ◽  
Author(s):  
H. Li ◽  
M. Matheny ◽  
P. J. Scarpace

To investigate the role of beta 3-adrenergic receptors in the suppression of leptin gene expression, we fasted F-344 rats to decrease leptin mRNA levels, refed the rats to stimulate leptin mRNA production, and examined the ability of the beta 3-adrenergic agonist CGP-12177 to prevent the rise in leptin mRNA levels. In the initial 2 h after CGP-12177 (0.75 mg/kg), there were significant reductions in both food consumption and leptin mRNA levels in epididymal, perirenal, and interscapular white adipose tissue. We were unable to detect leptin mRNA in interscapular brown adipose tissue (IBAT), whereas there was a significant increase in uncoupling protein mRNA levels in IBAT after CGP-12177. The suppression of leptin mRNA and food intake by CGP-12177 was confirmed in a second experiment using another rat strain, the F-344 x BN. Furthermore, refeeding after a period of fasting increased leptin mRNA, which was prevented by CGP-12177. These data indicate a role for beta 3-adrenergic-mediated regulation of leptin gene expression in nonmutant rodents and are consistent with other reports suggesting that beta 3-adrenergic agonists suppress food intake.


2021 ◽  
Author(s):  
Mingsheng Ye ◽  
Liping Luo ◽  
Qi Guo ◽  
Guanghua Lei ◽  
Chao Zeng ◽  
...  

Brown adipose tissue (BAT) is emerging as a target to beat obesity through the dissipation of chemical energy to heat. However, the molecular mechanisms of brown adipocyte thermogenesis remain to be further elucidated. Here, we show that KCTD10, a member of the polymerase delta-interacting protein 1 (PDIP1) family, was reduced in BAT by cold stress and a β3 adrenoceptor agonist. Moreover, KCTD10 level increased in the BAT of obese mice, and KCTD10 overexpression attenuates uncoupling protein 1 (UCP1) expression in primary brown adipocytes. BAT-specific KCTD10 knockdown mice had increased thermogenesis and cold tolerance protecting from high fat diet (HFD)-induced obesity. Conversely, overexpression of KCTD10 in BAT caused reduced thermogenesis, cold intolerance, and obesity. Mechanistically, inhibiting Notch signaling restored the KCTD10 overexpression suppressed thermogenesis. Our study presents that KCTD10 serves as an upstream regulator of notch signaling pathway to regulate BAT thermogenesis and whole-body metabolic function.


2020 ◽  
Author(s):  
Xuemei Liu ◽  
Xiyu Feng ◽  
Chao Deng ◽  
Lu Liu ◽  
Yanping Zeng ◽  
...  

Abstract BackgroundPrescription of second-generation antipsychotic drugs (SGAs) to childhood/adolescent has exponentially increased in recent years, which was associated with the greater risk of significant sedation, weight gain, and dyslipidemia. Statin is considered a potential preventive and treatment approach for reducing SGA-induced weight gain and dyslipidemia in schizophrenia patients. However, the effect of statin treatment in children and adolescents with SGA-induced dyslipidemia is not clearly demonstrated.MethodsTo investigate the efficacy of interventions of statin aimed at reversing SGA-induced dyslipidemia, young Sprague Dawley (SD) rats were treated orally with either olanzapine (1.0 mg/kg, t.i.d.), simvastatin (3.0 mg/kg, t.i.d.), olanzapine plus simvastatin (O+S), or vehicle (control) for 5 weeks.ResultsOlanzapine treatment increased weight gain, food intake and feeding efficiency compared to the control, while O+S co-treatment significantly reversed body weight gain but had no significant effect on food intake. Moreover, olanzapine treatment induced a slight but significant reduction in body temperature, with a decrease in locomotor activity. Fasting plasma glucose, triglycerides (TG), and total cholesterol (TC) levels were markedly elevated in the olanzapine-only group, whereas O+S co-treatment significantly ameliorated these changes. A down-regulating of uncoupling protein-1 (UCP1) and peroxisome-proliferator-activated receptor-γ co-activator-1α (PGC-1α) expression was observed in brown adipose tissue (BAT) in the olanzapine-only group, following a significant decrease in the ratio of phosphorylated PKA (p-PKA)/PKA. Interestingly, these protein changes could be reversed by co-treatment with O+B. Our results demonstrated simvastatin to be effective in ameliorating TC and TG elevated by olanzapine.ConclusionsModulation of BAT activity could be a partial mechanism in reducing metabolic side effects caused by SGAs in child and adolescent patients.


2020 ◽  
Author(s):  
Xuemei Liu ◽  
Xiyu Feng ◽  
Chao Deng ◽  
Lu Liu ◽  
Yanping Zeng ◽  
...  

Abstract Background Prescription of second-generation antipsychotic drugs (SGAs) to childhood/adolescent has exponentially increased in recent years, which was associated with the greater risk of significant weight gain and dyslipidemia. Statin is considered a potential preventive and treatment approach for reducing SGA-induced weight gain and dyslipidemia in schizophrenia patients. However, the effect of statin treatment in children and adolescents with SGA-induced dyslipidemia is not clearly demonstrated.Methods To investigate the efficacy of statin interventions for reversing SGA-induced dyslipidemia, young Sprague Dawley rats were treated orally with either olanzapine (1.0 mg/kg, t.i.d.), simvastatin (3.0 mg/kg, t.i.d.), olanzapine plus simvastatin (O+S), or vehicle (control) for 5 weeks. Results Olanzapine treatment increased weight gain, food intake and feeding efficiency compared to the control, while O+S co-treatment significantly reversed body weight gain but without significant effects on food intake. Moreover, olanzapine treatment induced a slight but significant reduction in body temperature, with a decrease in locomotor activity. Fasting plasma glucose, triglycerides (TG), and total cholesterol (TC) levels were markedly elevated in the olanzapine-only group, whereas O+S co-treatment significantly ameliorated these changes. Pronounced activation of lipogenic gene expression in the liver and down-regulated expression of uncoupling protein-1 (UCP1) and peroxisome-proliferator-activated receptor-γ co-activator-1α (PGC-1α) in brown adipose tissue (BAT) was observed in the olanzapine-only group. Interestingly, these protein changes could be reversed by co-treatment with O+B. Conclusions Simvastatin is effective in ameliorating TC and TG elevated by olanzapine. Modulation of BAT activity by statins could be a partial mechanism in reducing metabolic side effects caused by SGAs in child and adolescent patients.


2019 ◽  
Vol 51 (09) ◽  
pp. 608-617 ◽  
Author(s):  
Lucia Balagova ◽  
Jan Graban ◽  
Agnesa Puhova ◽  
Daniela Jezova

AbstractCatecholamine effects via β3-adrenergic receptors are important for the metabolism of the adipose tissue. Physical exercise is a core component of antiobesity regimens. We have tested the hypothesis that voluntary wheel running results in enhancement of β3-adrenergic receptor gene expression in the white and brown adipose tissues. The secondary hypothesis is that dietary tryptophan depletion modifies metabolic effects of exercise. Male Sprague-Dawley rats were assigned for sedentary and exercise groups with free access to running wheels for 3 weeks. All animals received normal control diet for 7 days. Both groups were fed either by low tryptophan (0.04%) diet or by control diet (0.2%) for next 2 weeks. The β3-adrenergic receptor mRNA levels in response to running increased in the retroperitoneal and epididymal fat pads. The gene expression of uncoupling protein-1 (UCP-1) was increased in the brown, while unchanged in the white fat tissues. Unlike control animals, the rats fed by low tryptophan diet did not exhibit a reduction of the white adipose tissue mass. Tryptophan depletion resulted in enhanced concentrations of plasma aldosterone and corticosterone, but had no influence on exercise-induced adrenal hypertrophy. No changes in β3-adrenergic receptor and cell proliferation measured by 5-bromo-2′-deoxyuridine incorporation in left heart ventricle were observed. The reduced β3-adrenergic receptor but not enhanced uncoupling protein-1 gene expression supports the hypothesis on hypoactive brown adipose tissue during exercise. Reduction in dietary tryptophan had no major influence on the exercise-induced changes in the metabolic parameters measured.


Author(s):  
Eric A. Wilson ◽  
Hui Sun ◽  
Zhenzhong Cui ◽  
Marshal T. Jahnke ◽  
Mritunjay Pandey ◽  
...  

The G protein subunits Gqα and G11α (Gq/11α) couple receptors to phospholipase C, leading to increased intracellular calcium. In this study we investigated the consequences of Gq/11α deficiency in the dorsomedial hypothalamus (DMH), a critical site for the control of energy homeostasis. Mice with DMH-specific deletion of Gq/11α (DMHGq/11KO) were generated by stereotaxic injection of AAV-Cre-GFP into the DMH of Gqαflox/flox:G11α-/- mice. Compared to control mice that received DMH injection of AAV-GFP, DMHGq/11KO mice developed obesity associated with reduced energy expenditure without significant changes in food intake or physical activity. DMHGq/11KO mice showed no defects in the ability of the melanocortin agonist melanotan II to acutely stimulate energy expenditure or to inhibit food intake. At room temperature (22oC) DMHGq/11KO mice showed reduced sympathetic nervous system activity in brown adipose tissue (BAT) and heart, accompanied with decreased basal BAT Ucp1 gene expression and lower heart rates. These mice were cold intolerant when acutely exposed to cold (6oC for 5 hours) and had decreased cold-stimulated BAT Ucp1 gene expression. DMHGq/11KO mice also failed to adapt to gradually declining ambient temperatures and to develop adipocyte browning in inguinal white adipose tissue although their BAT Ucp1 was proportionally stimulated. Consistent with impaired cold-induced thermogenesis, the onset of obesity in DMHGq/11KO mice was significantly delayed when housed under thermoneutral conditions (30ºC). Thus, our results show that Gqα and G11α in the DMH are required for the control of energy homeostasis by stimulating energy expenditure and thermoregulation.


Nutrients ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 796 ◽  
Author(s):  
Andrea Gille ◽  
Bojan Stojnic ◽  
Felix Derwenskus ◽  
Andreas Trautmann ◽  
Ulrike Schmid-Staiger ◽  
...  

Phaeodactylum tricornutum (P. tricornutum) comprise several lipophilic constituents with proposed anti-obesity and anti-diabetic properties. We investigated the effect of an ethanolic P. tricornutum extract (PTE) on energy metabolism in obesity-prone mice fed a high fat diet (HFD). Six- to eight-week-old male C57BL/6J mice were switched to HFD and, at the same time, received orally placebo or PTE (100 mg or 300 mg/kg body weight/day). Body weight, body composition, and food intake were monitored. After 26 days, blood and tissue samples were collected for biochemical, morphological, and gene expression analyses. PTE-supplemented mice accumulated fucoxanthin metabolites in adipose tissues and attained lower body weight gain, body fat content, weight of white adipose tissue (WAT) depots, and inguinal WAT adipocyte size than controls, independent of decreased food intake. PTE supplementation was associated with lower expression of Mest (a marker of fat tissue expandability) in WAT depots, lower gene expression related to lipid uptake and turnover in visceral WAT, increased expression of genes key to fatty acid oxidation and thermogenesis (Cpt1, Ucp1) in subcutaneous WAT, and signs of thermogenic activation including enhanced UCP1 protein in interscapular brown adipose tissue. In conclusion, these data show the potential of PTE to ameliorate HFD-induced obesity in vivo.


1996 ◽  
Vol 314 (1) ◽  
pp. 261-267 ◽  
Author(s):  
María-Jesus OBREGÓN ◽  
Barbara CANNON ◽  
Jan NEDERGAARD

The levels of mRNA coding for the uncoupling protein (UCP) and for lipoprotein lipase (LPL) were monitored in the brown adipose tissue of newborn rat pups. At 5 h after birth, the mRNA levels of UCP and LPL were high in pups exposed singly to 28 °C and low in pups kept singly at thermoneutrality (36 °C); in pups staying with the dam, the UCP mRNA levels were intermediate. However, the LPL mRNA levels were lower in pups staying with the dam than in pups at 36 °C, implying that factors additional to environmental temperature influenced LPL gene expression. Injection of noradrenaline into pups at thermoneutrality (36 °C) led to increases in UCP and LPL gene expression, but noradrenaline injections had no further effect in cold-exposed pups. The adrenergic effects were mediated via β-adrenergic receptors. The cold-induced increases in both UCP and LPL gene expression were abolished by the β-adrenergic antagonist propranolol. Thus differences in adrenergic responsiveness could not explain the differential expression of the UCP and LPL genes observed in pups staying with the dam. The presence of a physiological suppressor was examined by feeding single pups at 28 °C with different foods: nothing, water, Intralipid, cow's milk, rat milk and rat colostrum. None of these agents led to suppression of UCP gene expression, but colostrum led to a selective suppression of LPL gene expression. It was concluded that the genes for UCP and LPL were responsive to adrenergic stimuli immediately after birth, and it is suggested that a component of rat colostrum can selectively suppress LPL gene expression.


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