Photoperiod regulates arcuate nucleus POMC, AGRP, and leptin receptor mRNA in Siberian hamster hypothalamus

2000 ◽  
Vol 278 (1) ◽  
pp. R271-R281 ◽  
Author(s):  
Julian G. Mercer ◽  
Kim M. Moar ◽  
Alexander W. Ross ◽  
Nigel Hoggard ◽  
Peter J. Morgan
Keyword(s):  
Gene Expression ◽  
Arcuate Nucleus ◽  
Leptin Receptor ◽  
Separate Experiment ◽  
Siberian Hamsters ◽  
Hypothalamic Arcuate Nucleus ◽  
Melanin Concentrating Hormone ◽  
Specific Regulation ◽  
Plasma Leptin ◽  
Agouti Related Protein

Siberian hamsters decreased body weight by 30% during 18 wk in short day (SD) vs. long day (LD) controls. Subsequent imposed food deprivation (FD; 24 h) caused a further 10% decrease. In the hypothalamic arcuate nucleus (ARC), SDs reduced proopiomelanocortin (POMC) gene expression and agouti-related protein (AGRP) mRNA was elevated, changes that summate to reduced catabolic drive through the melanocortin receptors. There was no effect of photoperiod on neuropeptide Y (NPY), melanin concentrating hormone, orexin, or corticotropin-releasing factor mRNAs. Superimposed FD increased AGRP gene expression and caused a localized elevation of NPY mRNA in the ARC. Both adipose tissue leptin and ARC leptin receptor (OB-Rb) mRNAs were downregulated in SDs, whereas FD increased OB-Rb gene expression. Thus OB-Rb mRNA is differentially regulated by acute and chronic changes in plasma leptin in this species. In a separate experiment in LDs, AGRP gene expression was increased by 24 or 48 h FD, whereas POMC mRNA was downregulated in the caudal ARC. AGRP and NPY mRNAs were extensively coexpressed in the ARC, and their differential regulation by photoperiod and FD is suggestive of transcript-specific regulation at the level of individual neurons.

scholarly journals Changes in mRNA expression of arcuate nucleus appetite-regulating peptides during lactation in rats

2013 ◽  
Vol 52 (2) ◽  
pp. 97-109 ◽  
Author(s):  
Yoshihiro Suzuki ◽  
Keiko Nakahara ◽  
Keisuke Maruyama ◽  
Rieko Okame ◽  
Takuya Ensho ◽  
...  
Keyword(s):  
Food Intake ◽  
Mrna Expression ◽  
Arcuate Nucleus ◽  
Peptide Yy ◽  
Weaning Food ◽  
Hypothalamic Arcuate Nucleus ◽  
Pregnancy And Lactation ◽  
Acyl Ghrelin ◽  
Plasma Leptin ◽  
Agouti Related Protein

The contribution of hypothalamic appetite-regulating peptides to further hyperphagia accompanying the course of lactation in rats was investigated by using PCR array and real-time PCR. Furthermore, changes in the mRNA expression for appetite-regulating peptides in the hypothalamic arcuate nucleus (ARC) were analyzed at all stages of pregnancy and lactation, and also after weaning. Food intake was significantly higher during pregnancy, lactation, and after weaning than during non-lactation periods. During lactation, ARC expression of mRNAs for agouti-related protein (AgRP) and peptide YY was increased, whereas that of mRNAs for proopiomelanocortin (POMC) and cholecystokinin (CCK) was decreased, in comparison with non-lactation periods. The increase in AgRP mRNA expression during lactation was especially marked. The plasma level of leptin was significantly decreased during the course of lactation, whereas that of acyl-ghrelin was unchanged. In addition, food intake was negatively correlated with the plasma leptin level during lactation. This study has clarified synchronous changes in the expression of many appetite-regulating peptides in ARC of rats during lactation. Our results suggest that hyperphagia during lactation in rats is caused by decreases in POMC and CCK expression and increases in AgRP expression in ARC, the latter being most notable. Together with the decrease in the blood leptin level, such changes in mRNA expression may explain the further hyperphagia accompanying the course of lactation.

scholarly journals Nutritional Influences on Reproductive Neuroendocrine Output: Insulin, Leptin, and Orexigenic Neuropeptide Signaling in the Ovine Hypothalamus

Endocrinology ◽  
2007 ◽  
Vol 148 (11) ◽  
pp. 5313-5322 ◽  
Author(s):  
David W. Miller ◽  
Joanne L. Harrison ◽  
Ellen J. Bennett ◽  
Patricia A. Findlay ◽  
Clare L. Adam
Keyword(s):  
Gene Expression ◽  
Neuropeptide Y ◽  
Leptin Receptor ◽  
Nutritional Influences ◽  
Hypothalamic Arcuate Nucleus ◽  
Melanocortin Signaling ◽  
Neuroendocrine Responses ◽  
Peptide Gene ◽  
Plasma Leptin ◽  
The Brain

This study investigated how changing nutritional status may alter reproductive neuroendocrine (LH) output via circulating leptin and insulin signaling through orexigenic hypothalamic pathways. Thin sheep were given an increasing nutritional plane (INP), sheep with intermediate adiposity a static nutritional plane (SNP), and fat sheep a decreasing nutritional plane (DNP) for 6 wk. Mean group adiposities converged by wk 6, LH output increased in INP, remained unchanged in SNP, and decreased in DNP sheep. Plasma and cerebrospinal fluid (CSF) insulin and plasma leptin concentrations increased in INP but did not change in the SNP and DNP groups. In INP sheep, LH output correlated positively with adiposity and plasma and CSF insulin concentrations and negatively with orexigenic neuropeptide Y gene expression in the hypothalamic arcuate nucleus (ARC). In DNP sheep, LH output correlated positively with adiposity, CSF leptin concentrations, and ARC proopiomelanocortin gene expression and negatively with leptin receptor (OB-Rb) and agouti-related peptide gene expression in the ARC. These data are consistent with the feedback response to an increasing nutritional plane being mediated by increasing circulating insulin entering the brain and stimulating LH via inhibition of hypothalamic neuropeptide Y and the response to a decreasing nutritional plane being mediated by altered hypothalamic leptin signaling brought about by increased OB-Rb expression and decreased melanocortin signaling. Because end point adiposity was similar yet LH output was different, the hypothalamus apparently retains a nutritional memory, based on changes in orexigenic neuropeptide expression, that influences contemporary neuroendocrine responses.

Lateral ventricular ghrelin and fourth ventricular ghrelin induce similar increases in food intake and patterns of hypothalamic gene expression

2006 ◽  
Vol 290 (6) ◽  
pp. R1565-R1569 ◽  
Author(s):  
Kimberly P. Kinzig ◽  
Karen A. Scott ◽  
Jayson Hyun ◽  
Sheng Bi ◽  
Timothy H. Moran
Keyword(s):  
Gene Expression ◽  
Food Intake ◽  
Fourth Ventricle ◽  
Time Course ◽  
Arcuate Nucleus ◽  
Central Administration ◽  
Stimulatory Action ◽  
Hypothalamic Arcuate Nucleus ◽  
Ghrelin Receptors ◽  
The Brain

The gut peptide ghrelin has been shown to stimulate food intake after both peripheral and central administration, and the hypothalamic arcuate nucleus has been proposed to be the major site for mediating this feeding stimulatory action. Ghrelin receptors are widely distributed in the brain, and hindbrain ghrelin administration has been shown to potently stimulate feeding, suggesting that there may be other sites for ghrelin action. In the present study, we have further assessed potential sites for ghrelin action by comparing the ability of lateral and fourth ventricular ghrelin administration to stimulate food intake and alter patterns of hypothalamic gene expression. Ghrelin (0.32, 1, or 3.2 nmol) in the lateral or fourth ventricle significantly increased food intake in the first 4 h after injection, with no ventricle-dependent differences in degree or time course of hyperphagia. One nanomole of ghrelin into either the lateral or fourth ventricle resulted in similar increases in arcuate nucleus neuropeptide Y mRNA expression. Expression levels of agouti-related peptide or proopiomelanocortin mRNA were not affected by ghrelin administration. These data demonstrate that ghrelin can affect food intake and hypothalamic gene expression through interactions at multiple brain sites.

Influence of photoperiod and gonadal status on food intake, adiposity, and gene expression of hypothalamic appetite regulators in a seasonal mammal

2007 ◽  
Vol 292 (1) ◽  
pp. R242-R252 ◽  
Author(s):  
Chantacha Anukulkitch ◽  
Alexandra Rao ◽  
Frank R. Dunshea ◽  
Dominique Blache ◽  
Gerald A. Lincoln ◽  
...  
Keyword(s):  
Gene Expression ◽  
Food Intake ◽  
Arcuate Nucleus ◽  
Leptin Receptor ◽  
Reproductive Axis ◽  
Pomc Gene ◽  
Gonadal Status ◽  
Long Photoperiod ◽  
Refractory Phase

We studied the effects of photoperiod on metabolic profiles, adiposity, and gene expression of hypothalamic appetite-regulating peptides in gonad-intact and castrated Soay rams. Groups of five to six animals were studied 6, 18, or 30 wk after switching from long photoperiod (LP: 16 h of light) to short photoperiod (SP: 8 h of light). Reproductive and metabolic indexes were measured in blood plasma. Expression of neuropeptide Y (NPY), proopiomelanocortin (POMC), and leptin receptor (ObRb) in the arcuate nucleus was measured using in situ hybridization. Testosterone levels of intact animals were low under LP, increased to a peak at 16 wk under SP, and then declined. Voluntary food intake (VFI) was high under LP in both intact and castrated animals, decreased to a nadir at 12–16 wk under SP, and then recovered, but only in intact rams as the reproductive axis became photorefractory to SP. NPY gene expression varied positively and POMC expression varied negatively with the cycle in VFI, with differences between intact and castrate rams in the refractory phase. ObRb expression decreased under SP, unrelated to changes in VFI. Visceral fat weight also varied between the intact and castrated animals across the cycle. We conclude that 1) photoperiodic changes in VFI reflect changes in NPY and POMC gene expression, 2) changes in ObRb gene expression are not necessarily determinants of changes in VFI, 3) gonadal status affects the pattern of VFI that changes with photoperiod, and 4) in the absence of gonadal factors, animals can eat less but gain adiposity.

scholarly journals Global transcriptome analysis of rat hypothalamic arcuate nucleus demonstrates reversal of hypothalamic gliosis following surgically and diet induced weight loss

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Pernille Barkholt ◽  
Kristoffer T. G. Rigbolt ◽  
Mechthilde Falkenhahn ◽  
Thomas Hübschle ◽  
Uwe Schwahn ◽  
...  
Keyword(s):  
Gene Expression ◽  
Weight Loss ◽  
Molecular Mechanisms ◽  
Arcuate Nucleus ◽  
Gene Expression Signature ◽  
Global Gene Expression ◽  
Metabolic Effects ◽  
Expression Of Genes ◽  
Hypothalamic Arcuate Nucleus ◽  
Laser Capture

Abstract The central mechanisms underlying the marked beneficial metabolic effects of bariatric surgery are unclear. Here, we characterized global gene expression in the hypothalamic arcuate nucleus (Arc) in diet-induced obese (DIO) rats following Roux-en-Y gastric bypass (RYGB). 60 days post-RYGB, the Arc was isolated by laser-capture microdissection and global gene expression was assessed by RNA sequencing. RYGB lowered body weight and adiposity as compared to sham-operated DIO rats. Discrete transcriptome changes were observed in the Arc following RYGB, including differential expression of genes associated with inflammation and neuropeptide signaling. RYGB reduced gene expression of glial cell markers, including Gfap, Aif1 and Timp1, confirmed by a lower number of GFAP immunopositive astrocyte profiles in the Arc. Sham-operated weight-matched rats demonstrated a similar glial gene expression signature, suggesting that RYGB and dietary restriction have common effects on hypothalamic gliosis. Considering that RYGB surgery also led to increased orexigenic and decreased anorexigenic gene expression, this may signify increased hunger-associated signaling at the level of the Arc. Hence, induction of counterregulatory molecular mechanisms downstream from the Arc may play an important role in RYGB-induced weight loss.

scholarly journals Age-associated gene expression changes in the arcuate nucleus of male rhesus macaques

2017 ◽  
Vol 59 (2) ◽  
pp. 141-149 ◽  
Author(s):  
Dominique H Eghlidi ◽  
Vasilios T Garyfallou ◽  
Steven G Kohama ◽  
Henryk F Urbanski
Keyword(s):  
Gene Expression ◽  
Arcuate Nucleus ◽  
Rhesus Macaques ◽  
Sex Steroid ◽  
Steroid Dependent ◽  
Reproductive Axis ◽  
Significant Gene ◽  
Hypothalamic Arcuate Nucleus ◽  
Male Rhesus ◽  
Arc Gene

The hypothalamic arcuate nucleus (ARC) represents a major component of the neuroendocrine reproductive axis and plays an important role in controlling the onset of puberty as well as age-associated reproductive senescence. Although significant gene expression changes have been observed in the ARC during sexual maturation, it is unclear what changes occur during aging, especially in males. Therefore, in the present study, we profiled the expression of reproduction-related genes in the ARC of young and old male rhesus macaques, as well as old males that had received 6 months of hormone supplementation (HS) in the form of daily testosterone and dehydroepiandrosterone; we also compared morning vs night ARC gene expression in the old males. Using Affymetrix gene microarrays, we found little evidence for age-associated expression changes for genes associated with the neuroendocrine reproductive axis, whereas using qRT-PCR, we detected a similar age-associated decrease in PGR (progesterone receptor) that we previously observed in postmenopausal females. We also detected a sex-steroid-dependent and age-associated decrease in androgen receptor (AR) expression, with highest AR levels being expressed at night (i.e., coinciding with the natural peak in daily testosterone secretion). Finally, unlike previous observations made in females, we did not find a significant age-associated increase in KISS1 (Kisspeptin) or TAC3 (Neurokinin B) expression in the ARC of males, most likely because the attenuation of circulating sex-steroid levels in the males was much less than that in postmenopausal females. Taken together, the data highlight some similarities and differences in ARC gene expression between aged male and female nonhuman primates.

scholarly journals Hypothyroidism Compromises Hypothalamic Leptin Signaling in Mice

2013 ◽  
Vol 27 (4) ◽  
pp. 586-597 ◽  
Author(s):  
Claudia Groba ◽  
Steffen Mayerl ◽  
Alies A. van Mullem ◽  
Theo J. Visser ◽  
Veerle M. Darras ◽  
...  
Keyword(s):  
Arcuate Nucleus ◽  
Leptin Receptor ◽  
Cytokine Signaling ◽  
Suppressor Of Cytokine Signaling ◽  
Double Knockout ◽  
Hypothalamic Arcuate Nucleus ◽  
The Central Nervous System ◽  
Leptin Expression ◽  
The Impact

Abstract The impact of thyroid hormone (TH) on metabolism and energy expenditure is well established, but the role of TH in regulating nutritional sensing, particularly in the central nervous system, is only poorly defined. Here, we studied the consequences of hypothyroidism on leptin production as well as leptin sensing in congenital hypothyroid TRH receptor 1 knockout (Trhr1 ko) mice and euthyroid control animals. Hypothyroid mice exhibited decreased circulating leptin levels due to a decrease in fat mass and reduced leptin expression in white adipose tissue. In neurons of the hypothalamic arcuate nucleus, hypothyroid mice showed increased leptin receptor Ob-R expression and decreased suppressor of cytokine signaling 3 transcript levels. In order to monitor putative changes in central leptin sensing, we generated hypothyroid and leptin-deficient animals by crossing hypothyroid Trhr1 ko mice with the leptin-deficient ob/ob mice. Hypothyroid Trhr1/ob double knockout mice showed a blunted response to leptin treatment with respect to body weight and food intake and exhibited a decreased activation of phospho-signal transducer and activator of transcription 3 as well as a up-regulation of suppressor of cytokine signaling 3 upon leptin treatment, particularly in the arcuate nucleus. These data indicate alterations in the intracellular processing of the leptin signal under hypothyroid conditions and thereby unravel a novel mode of action by which TH affects energy metabolism.

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