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Feichtinger RG, Pétervári E, Zopf M, Vidali S, Aminzadeh-Gohari S, Mayr JA, Kofler B, Balaskó M. Effects of alpha-melanocyte-stimulating hormone on mitochondrial energy metabolism in rats of different age-groups. Neuropeptides 2017; 64:123-130. [PMID: 27614713 DOI: 10.1016/j.npep.2016.08.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Revised: 08/24/2016] [Accepted: 08/25/2016] [Indexed: 12/12/2022]
Abstract
Hypothalamic alpha-melanocyte-stimulating hormone (α-MSH) is a key catabolic mediator of energy homeostasis. Its anorexigenic and hypermetabolic effects show characteristic age-related alterations that may be part of the mechanism of middle-aged obesity and geriatric anorexia/cachexia seen in humans and other mammals. We aimed to investigate the role of α-MSH in mitochondrial energy metabolism during the course of aging in a rodent model. To determine the role of α-MSH in mitochondrial energy metabolism in muscle, we administered intracerebroventricular (ICV) infusions of α-MSH for 7-days to different age-groups of male Wistar rats. The activities of oxidative phosphorylation complexes I to V and citrate synthase were determined and compared to those of age-matched controls. We also quantified mitochondrial DNA (mtDNA) copy number and measured the expression of the master regulators of mitochondrial biogenesis, peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) and peroxisome proliferator-activated receptor gamma (PPARγ). The peptide reduced weight gain in juvenile rats to one fifth of that of controls and increased the weight loss in older animals by about five fold. Mitochondrial DNA copy number inversely correlated with changes in body weight in controls, but not in α-MSH-treated animals. The strong increase in body weight in young rats was associated with a low mtDNA copy number and high PPARγ mRNA levels in controls. Expression of PGC-1α and PPARγ declined with age, whereas OXPHOS and citrate synthase enzyme activities were unchanged. In contrast, α-MSH treatment suppressed OXPHOS enzyme and citrate synthase activity. In conclusion, our results showed age-related differences in the metabolic effects of α-MSH. In addition, administration of α-MSH suppressed citrate synthase and OXPHOS activities independent of age. These findings suggest that α-MSH exposure may inhibit mitochondrial biogenesis.
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Affiliation(s)
- René G Feichtinger
- Laura Bassi Centre of Expertise-THERAPEP, Research Program for Receptor Biochemistry and Tumor Metabolism, Department of Pediatrics, Paracelsus Medical University, Salzburg, Austria
| | - Erika Pétervári
- Institute for Translational Medicine, Medical School, University of Pécs, Hungary
| | - Michaela Zopf
- Laura Bassi Centre of Expertise-THERAPEP, Research Program for Receptor Biochemistry and Tumor Metabolism, Department of Pediatrics, Paracelsus Medical University, Salzburg, Austria
| | - Silvia Vidali
- Laura Bassi Centre of Expertise-THERAPEP, Research Program for Receptor Biochemistry and Tumor Metabolism, Department of Pediatrics, Paracelsus Medical University, Salzburg, Austria
| | - Sepideh Aminzadeh-Gohari
- Laura Bassi Centre of Expertise-THERAPEP, Research Program for Receptor Biochemistry and Tumor Metabolism, Department of Pediatrics, Paracelsus Medical University, Salzburg, Austria
| | - Johannes A Mayr
- Department of Pediatrics, Paracelsus Medical University, Salzburg, Austria
| | - Barbara Kofler
- Laura Bassi Centre of Expertise-THERAPEP, Research Program for Receptor Biochemistry and Tumor Metabolism, Department of Pediatrics, Paracelsus Medical University, Salzburg, Austria.
| | - Márta Balaskó
- Institute for Translational Medicine, Medical School, University of Pécs, Hungary
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Armbruszt S, Figler M, Ábrahám H. Stability of CART peptide expression in the nucleus accumbens in aging. ACTA BIOLOGICA HUNGARICA 2015; 66:1-13. [PMID: 25740434 DOI: 10.1556/abiol.66.2015.1.1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Aging is accompanied by changes of several anorexigenic and orexigenic neuropeptides expressed in various brain areas that control food intake and these changes correlate with senescent anorexia. During aging expression of cocaine- and amphetamine-regulated transcript (CART) peptide was reported to be reduced in the hypothalamic nuclei related to food intake. Although CART peptide is abundant in the nucleus accumbens that also plays a crucial role in the food intake regulation, no data is available about the CART peptide expression in this region through aging. In the present study, CART peptide immunoreactivity was compared in the nucleus accumbens of young adult (4- and 7-month-old) middle-aged (15-month-old) and aging (25-32-month-old) Long-Evans rats. The density of CART-immunoreactive cells and axon terminals in the nucleus accumbens was measured with computer-aided densitometry. CART-immunodensity was similar in the old rats and in the younger animals without significant difference between age groups. In addition, no gender-difference was observed when CART-immunoreactivities in the nucleus accumbens of male and female animals were compared. Our results indicate that CART peptide expression in the nucleus accumbens is stable in adults and does not change with age.
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Affiliation(s)
- Simon Armbruszt
- University of Pécs Institute of Nutritional Sciences and Dietetics, Faculty of Health Sciences Pécs Hungary
| | - Mária Figler
- University of Pécs Institute of Nutritional Sciences and Dietetics, Faculty of Health Sciences Pécs Hungary
| | - Hajnalka Ábrahám
- University of Pécs Central Electron Microscopic Laboratory, Faculty of Medicine Pécs Hungary
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Banki E, Pakai E, Gaszner B, Zsiboras C, Czett A, Bhuddi PRP, Hashimoto H, Toth G, Tamas A, Reglodi D, Garami A. Characterization of the thermoregulatory response to pituitary adenylate cyclase-activating polypeptide in rodents. J Mol Neurosci 2014; 54:543-54. [PMID: 24994541 DOI: 10.1007/s12031-014-0361-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2014] [Accepted: 06/23/2014] [Indexed: 12/19/2022]
Abstract
Administration of the long form (38 amino acids) of pituitary adenylate cyclase-activating polypeptide (PACAP38) into the central nervous system causes hyperthermia, suggesting that PACAP38 plays a role in the regulation of deep body temperature (T b). In this study, we investigated the thermoregulatory role of PACAP38 in details. First, we infused PACAP38 intracerebroventricularly to rats and measured their T b and autonomic thermoeffector responses. We found that central PACAP38 infusion caused dose-dependent hyperthermia, which was brought about by increased thermogenesis and tail skin vasoconstriction. Compared to intracerebroventricular administration, systemic (intravenous) infusion of the same dose of PACAP38 caused significantly smaller hyperthermia, indicating a central site of action. We then investigated the thermoregulatory phenotype of mice lacking the Pacap gene (Pacap (-/-)). Freely moving Pacap (-/-) mice had higher locomotor activity throughout the day and elevated deep T b during the light phase. When the Pacap (-/-) mice were loosely restrained, their metabolic rate and T b were lower compared to their wild-type littermates. We conclude that PACAP38 causes hyperthermia via activation of the autonomic cold-defense thermoeffectors through central targets. Pacap (-/-) mice express hyperkinesis, which is presumably a compensatory mechanism, because under restrained conditions, these mice are hypometabolic and hypothermic compared to controls.
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Affiliation(s)
- Eszter Banki
- Department of Anatomy PTE-MTA "Lendulet" PACAP Research Team, Medical School, University of Pecs, Pecs, Hungary
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In S, Lee DS, Choi B, Kim MJ. Nicotinamide induces male-specific body weight loss in the postnatal period through molecular regulation of the hypothalamus and liver. Neurosci Lett 2012; 530:166-71. [PMID: 23043891 DOI: 10.1016/j.neulet.2012.09.055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2012] [Revised: 09/13/2012] [Accepted: 09/27/2012] [Indexed: 11/24/2022]
Abstract
Molecular mechanisms of body weight control have been discovered recently and much research focuses on the hypothalamic regulation of food intake and the hepatic regulation of glucose utility. We previously reported that postnatal nicotinamide treatment reduced brain dopamine and body weight. To further investigate the differential effects of nicotinamide-mediated body weight loss, nicotinamide (i.p. 100mg/kg) was injected into postnatal and adult mice twice a week for 4 weeks. Interestingly, following nicotinamide treatment, male postnatal mice displayed reduced body weight and spontaneous motor activity. No significant changes were observed in adult and postnatal female mice or adult male mice following nicotinamide treatment. In male postnatal mice, hypothalamic agouti-related peptide (AGRP) and proopiomelanocortin (POMC) levels were increased in the arcuate nucleus following nicotinamide treatment. Neuropeptide Y (NPY) levels were unchanged in both male and female mice. Additionally, nicotinamide-injected male postnatal mice had increased glucose 6-phosphatase (G6Pase) and decreased phosphoenolpyruvate carboxykinase (PEPCK) expression in liver. These results indicate that hypothalamic POMC and hepatic PEPCK are important molecules that mediate nicotinamide-induced weight loss in postnatal male mice.
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Affiliation(s)
- Sua In
- Department of Anatomy and Neurobiology, College of Medicine, Hallym University, Chuncheon, Gangwon-Do 200-702, Republic of Korea
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Dâmaso AR, de Piano A, Sanches PL, Corgosinho F, Tock L, Oyama LM, Tock L, do Nascimento CMO, Tufik S, de Mello MT. Hyperleptinemia in obese adolescents deregulates neuropeptides during weight loss. Peptides 2011; 32:1384-91. [PMID: 21641948 DOI: 10.1016/j.peptides.2011.04.025] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2011] [Revised: 04/28/2011] [Accepted: 04/28/2011] [Indexed: 10/18/2022]
Abstract
Leptin has emerged over the past decade as a key hormone not only in energy balance regulation but also in neuroendocrine and inflammatory processes. The aim of the present study was to evaluate whether hyperleptinemia deregulates neuropeptides during weight loss. A total of 86 post-pubertal obese adolescents (with or without hyperleptinemia) participated in one year of interdisciplinary weight loss therapy (clinical, nutritional, psychological and exercise-related). Adipokine and neuropeptide concentrations were measured by ELISA, visceral fat was measured by ultrasound and body composition was measured by pletismography. The hyperleptinemic patients presented a lower alpha-MSH concentration and higher NPY/AgRP ratio while the adiponectin/leptin (A/L) ratio was lower compared with the non-hyperleptinemic group. After therapy, significant improvements in BM, BMI, body fat mass, visceral and subcutaneous fat, HOMA-IR, QUICKI, total cholesterol and triglycerides were observed in both groups. Indeed, we observed significant increases in adiponectin and A/L as well as reductions in leptin and NPY/AgRP ratio in the hyperleptinemic group. In the stepwise multiple linear regression analysis with leptin concentration as the dependent variable, α-MSH and body fat mass (%) were the independent predictors to explain leptin concentration. For the entire group, we found positive correlations between leptinemia and BMI and body fat mass (%) as well as a negative correlation with free fat mass (%) and alpha-MSH. Finally, we verified negative correlations between adiponectin/leptin ratio with total cholesterol and LDL-c, only in hyperleptinemic patients. In conclusion, the hyperleptinemia in obese adolescents deregulates neuropeptides during weight loss.
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Affiliation(s)
- Ana R Dâmaso
- Biosciences Department, Federal University of São Paulo-Paulista Medicine School-UNIFESP-EPM, São Paulo, Brazil.
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Pétervári E, Szabad Á, Soós S, Garami A, Székely M, Balaskó M. Central alpha-MSH infusion in rats: Disparate anorexic vs. metabolic changes with aging. ACTA ACUST UNITED AC 2011; 166:105-11. [DOI: 10.1016/j.regpep.2010.10.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2010] [Revised: 08/30/2010] [Accepted: 10/04/2010] [Indexed: 12/24/2022]
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Soos S, Petervari E, Szekely M, Jech-Mihalffy A, Balasko M. Complex catabolic effects of central alpha-MSH infusion in rats of altered nutritional states: differences from leptin. J Mol Neurosci 2010; 43:209-16. [PMID: 20953734 DOI: 10.1007/s12031-010-9462-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2010] [Accepted: 10/05/2010] [Indexed: 01/15/2023]
Abstract
The hypothalamic melanocortin (MC) system is a major catabolic regulator of energy balance: it suppresses food intake (FI), elevates metabolic rate, and reduces body weight (BW). The primary activator of the MC system [mainly via the alpha-melanocyte stimulating hormone (alpha-MSH)] is the adipocyte-derived leptin. With increasing BW, resistance develops to leptin-induced anorexia, but independent of this, in genetically modified animals, some alpha-MSH actions were maintained. We investigated the responsiveness of the MC system in its complexity (FI vs. metabolic correlates) in genetically intact male Wistar rats of different nutritional states (and different leptin sensitivities), i.e., in rats aged 2 months [normally fed (NF2)] or 6 months [calorie-restricted (CR6), fed ad libitum (NF6), and high-fat diet-induced obese (HF6) groups]. A 7-day-long, 1-μg/μl/h intracerebroventricular infusion of alpha-MSH reduced BW in all groups, particularly in NF6 and NF2 animals, and even CR6 rats lost BW upon alpha-MSH infusion (in contrast to leptin administration). Anorexia developed in NF2-NF6 and less in CR6 groups, and some FI fall was also seen in HF6 rats. The hypermetabolic effects (temperature/heart rate elevations) were most pronounced in CR6 and next in HF6 rats. These data suggest that alpha-MSH responsiveness is maintained in various forms (depending on nutritional state), despite obesity-induced leptin resistance.
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Affiliation(s)
- Szilvia Soos
- Department of Pathophysiology and Gerontology, Medical School, University of Pecs, 12 Szigeti ut, Pecs H-7624, Hungary
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Pétervári E, Garami A, Soós S, Székely M, Balaskó M. Age-dependence of alpha-MSH-induced anorexia. Neuropeptides 2010; 44:315-22. [PMID: 20382426 DOI: 10.1016/j.npep.2010.03.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2009] [Revised: 02/23/2010] [Accepted: 03/17/2010] [Indexed: 11/20/2022]
Abstract
Long-term regulation of energy balance involves two major trends: first age-related obesity develops in the middle-aged, later it is followed by anorexia of aging (sarcopenia and/or cachexia). A dynamic balance between orexigenic and anorexigenic neuropeptides is essential for the regulation of energy homeostasis. Special imbalances of neuropeptide effects may be assumed corresponding to different age-periods. Anorexia induced by acute alpha-MSH (alpha-melanocyte stimulating hormone; endogenous melanocortin agonist) injections was analyzed in male Wistar rats aged 6-9 weeks (juvenile), 3-4 months (young adult), 6 or 12 months (two middle-aged groups), 18 months (aging) and 24-26 months (old). Alpha-MSH injected through a preimplanted intracerebroventricular (ICV) cannula (compared with saline injection) dose-dependently suppressed spontaneous food intake and also re-feeding following 24-h fasting, but the rate of suppression varied between age-groups. An ICV injection of 5 microg alpha-MSH attenuated the 2-h re-feeding by 21.9+/-3.2% in juvenile rats, strongly (68.7+/-2.5%) suppressed it in young adults, the suppression became progressively weaker in the two middle-aged groups (55.7+/-4.9%, vs. 26.4+/-4.9%, respectively), but it turned extreme in aging (94.7+/-4.2%) and old (74.3+/-4.5%) rats. Body composition also changed with age: unlike the tibialis anterior muscle, the epididymal and retroperitoneal fat pads increased until middle-age and remained large even in old animals, while the measured indicator of muscle mass decreased in the oldest group. The food intake suppressing and body weight decreasing effects of a 7-day-long ICV infusion of 1 microg/h alpha-MSH were weakest in the 12-month-old and most pronounced in the 24 month-old rats. In conclusion, responsiveness to the anorexic effect of alpha-MSH varies with age, with a nadir of the curve in the middle-aged, and a peak in the aging and old animals. This age-related nadir of melanocortin-responsiveness may promote obesity in middle-aged rats, while the tendency for anorexia and incipient sarcopenia of old (still obese) rats may result from age-related melanocortin-hypersensitivity rather than from adiposity.
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Affiliation(s)
- E Pétervári
- Department of Pathophysiology and Gerontology, Medical School, University of Pécs, Pécs, Hungary
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Balaskó M, Garami A, Soós S, Koncsecskó-Gáspár M, Székely M, Pétervári E. Central alpha-MSH, energy balance, thermal balance, and antipyresis. J Therm Biol 2010. [DOI: 10.1016/j.jtherbio.2010.05.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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