Leptin secretion and hypothalamic neuropeptide and receptor gene expression in sheep

2002 ◽  
Vol 282 (4) ◽  
pp. R1227-R1235 ◽  
Author(s):  
Annette Sorensen ◽  
Clare L. Adam ◽  
Pat A. Findlay ◽  
Michel Marie ◽  
Louise Thomas ◽  
...  
Keyword(s):  
Gene Expression ◽  
Receptor Gene ◽  
Negative Energy ◽  
Receptor Expression ◽  
Melanocortin Receptor ◽  
Hypothalamic Nucleus ◽  
Hypothalamic Arcuate Nucleus ◽  
Ad Libitum ◽  
Peptide Gene ◽  
Plasma Leptin

Peripheral and hypothalamic mechanisms underlying the hyperphagia of lactation have been investigated in sheep. Sheep were fed ad libitum and killed at 6 and 18 days of lactation; ad libitum-fed nonlactating sheep were killed as controls. Despite increased food intake, lactating ewes were in negative energy balance. Lactation decreased plasma leptin and adipose tissue leptin mRNA concentrations. OB-Rb gene expression, determined by in situ hybridization, was increased in the hypothalamic arcuate nucleus (ARC) and ventromedial hypothalamic nucleus (VMH) at both stages of lactation. Neuropeptide Y (NPY) was increased by lactation in both the ARC and dorsomedial hypothalamus (DMH), although increased gene expression in the DMH was only apparent at day 18 of lactation. Gene expression was decreased for cocaine- and amphetamine-regulated transcript (CART) in the ARC and VMH and for proopiomelanocortin in ARC during lactation. Agouti-related peptide gene expression was increased in the ARC, and melanocortin receptor expression was unchanged in both the ARC and VMH with lactation. Thus the hypoleptinemia of lactation may activate NPY orexigenic pathways and attenuate anorexigenic melanocortin and CART pathways in the hypothalamus to promote the hyperphagia 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.

Parasite-induced anorexia: leptin, insulin and corticosterone responses to infection with the nematode, Nippostrongylus brasiliensis

Parasitology ◽  
1999 ◽  
Vol 118 (1) ◽  
pp. 117-123 ◽  
Author(s):  
H. C. ROBERTS ◽  
L. J. HARDIE ◽  
L. H. CHAPPELL ◽  
J. G. MERCER
Keyword(s):  
Gene Expression ◽  
Energy Balance ◽  
Neuropeptide Y ◽  
Post Infection ◽  
Plasma Insulin ◽  
Negative Energy ◽  
Nippostrongylus Brasiliensis ◽  
Corticotrophin Releasing Factor ◽  
Ad Libitum ◽  
Plasma Leptin

The nematode parasite, Nippostrongylus brasiliensis, induces a biphasic anorexia in its rat host. The mechanisms, underlying this anorexia and its possible advantages to the host or parasite are unknown. We have investigated the effect of acute (12–24 h) and chronic (2–17 days) infections on plasma concentrations of leptin, insulin and corticosterone, and on hypothalamic expression of neuropeptide Y, galanin and corticotrophin-releasing factor genes. Plasma leptin was elevated in infected rats relative to uninfected ad libitum-fed controls and pair-fed controls in 12 h infections initiated at dark onset and in infections of 2 days' duration. At other times prior to parasite expulsion, plasma leptin in infected and pair-fed rats was lower than that of uninfected ad libitum-fed controls, reflecting the existing state of negative energy balance. Elevated plasma leptin concentrations in infected rats at day 2 post-infection were accompanied by reduced neuropeptide Y gene expression in the hypothalamic arcuate nucleus compared with both ad libitum control and pair-fed animals, and by lowered corticotrophin-releasing factor gene expression in the paraventricular nucleus relative to pair-feds. Twelve hour infections were characterized by a substantial increase in plasma corticosterone that was independent of reduced food intake, and in 12 h infections initiated at dark onset, where plasma leptin was elevated, there was also increased plasma insulin concentration in infected rats. In longer infections, differences between the groups in plasma insulin and corticosterone concentration were only observed at day 4 post-infection. In summary, perturbations to leptin, insulin and corticosterone signals early in infection may have a causative role and might feed back onto hypothalamic gene expression, whereas subsequent changes in these parameters are more likely to be secondary to negative energy balance.

Spatially Organized Response Zones in Rat Olfactory Epithelium

1997 ◽  
Vol 77 (4) ◽  
pp. 1950-1962 ◽  
Author(s):  
John W. Scott ◽  
Donna E. Shannon ◽  
Jeff Charpentier ◽  
Lisa M. Davis ◽  
Craig Kaplan
Keyword(s):  
Gene Expression ◽  
Functional Groups ◽  
Olfactory Epithelium ◽  
Olfactory Receptor ◽  
Receptor Gene ◽  
Chemical Properties ◽  
Receptor Expression ◽  
Response Distribution ◽  
Chemical Structures ◽  
Four Electrodes

Scott, John W., Donna E. Shannon, Jeff Charpentier, Lisa M. Davis, and Craig Kaplan. Spatially organized response zones in rat olfactory epithelium. J. Neurophysiol. 77: 1950–1962, 1997. Electroolfactogram recordings were made with a four-electrode assembly from the olfactory epithelium overlying the endoturbinate bones facing the nasal septum. In this study we tested whether odors of different chemical structures produce maximal responses along longitudinally oriented regions following the olfactory receptor gene expression zones described in the literature. The distribution of responses along the dorsal-to-ventral direction of this epithelium (i.e., across the expression zones) was tested in two types of experiments. In one, four electrodes were fixed along the dorsal-to-ventral axis of one turbinate bone. In the other, four electrodes were placed in corresponding positions on four turbinate bones and moved together up toward the top of the bone. These experiments compared the odorants limonene and α-terpinene, which are simple hydrocarbons, with carvone and menthone, which differ from the hydrocarbons by the presence of ketone groups. All responses were standardized to an amyl acetate or ethyl butyrate standard. The responses to limonene and α-terpinene were often larger for the ventral electrodes. The responses to carvone and menthone were largest for the dorsal electrodes. Intermediate electrodes gave responses that were intermediate in amplitude for these odors. The possibility that direction of air flow caused the observed response distributions was directly tested in experiments with odor nozzles placed in two positions. The relatively larger dorsal responses to carvone and relatively larger ventral responses to limonene were present despite odor nozzle position. We conclude that the responses to this set of odors vary systematically in a fashion parallel to the four gene expression zones. The odorant property that governs this response distribution may be related to the presence of oxygen-containing functional groups. Certain odors evoked larger responses at the intermediate electrode sites than at other sites. Cineole was the best example of this effect. This observation shows that not all oxygen-containing functional groups produce the same effect. Although we cannot exclude other possible mechanisms, these three response gradients may be produced by the four receptor expression zones described for many of the putative olfactory receptor genes. Therefore many of the receptors in each zone may share common properties. It remains to be determined whether this zonal input is significant in central odor processing. However, the correlation of odor chemical properties with the structure of receptor molecules in each zone may provide significant leads to structure-function relationships in vertebrate olfaction.

Hypothalamic GH receptor gene expression in the rat: effects of altered GH status

1995 ◽  
Vol 147 (2) ◽  
pp. 225-234 ◽  
Author(s):  
P A Bennett ◽  
A Levy ◽  
S Sophokleous ◽  
I C A F Robinson ◽  
S L Lightman
Keyword(s):  
Gene Expression ◽  
Receptor Gene ◽  
Feedback Regulation ◽  
Receptor Expression ◽  
Physiological Regulation ◽  
Background Strain ◽  
Gh Receptor ◽  
The Central Nervous System ◽  
Receptor Gene Expression

Abstract GH synthesis and release from the anterior pituitary is governed by the opposing actions of somatostatin (SS) and GH-releasing factor (GRF), derived from the periventricular and arcuate nucleus (ARC) of the hypothalamus respectively. GH is known to regulate its own release by hypothalamic autofeedback mechanisms, but the extent to which this is a direct effect rather than indirectly via the generation of IGFs is still a subject of debate. GH receptors are known to be present in the hypothalamus, but their physiological regulation is poorly understood. We therefore used in situ hybridization histochemistry to investigate the effects of GH status on hypothalamic GH receptor gene expression, using hypophysectomized normal and dw/dw dwarf rats as models of acquired and congenital GH deficiency. Hypophysectomy resulted in a timedependent reduction in GH receptor gene expression. ARC GH receptor transcripts in untreated dw/dw dwarf rats were half those found in normal animals of the same background strain (16·8±1·7 vs 9·3± 1·9 d.p.m./mg, P<0·05). Increasing circulating GH by peripheral infusion of 200 μg human GH (hGH)/day for 6 days increased ARC GH receptor expression in dw/dw rats to normal. In contrast, central infusions of hGH at 26·4 and 79·2 μg/day for 6 days in normal rats lowered ARC GH receptor gene expression. The sensitivity of GH receptor gene expression within the central nervous system to peripheral and central GH levels suggests that feedback regulation of GRF and/or SS may be mediated directly by these receptors, and that the sensitivity to GH feedback is also subject to autoregulation by GH altering its own receptor expression. Journal of Endocrinology (1995) 147, 225–234

scholarly journals Modulation of glomerular endothelin and endothelin receptor gene expression in aminonucleoside-induced nephrosis.

1995 ◽  
Vol 5 (8) ◽  
pp. 1585-1590
Author(s):  
T Nakamura ◽  
I Ebihara ◽  
M Fukui ◽  
S Osada ◽  
Y Tomino ◽  
...  
Keyword(s):  
Gene Expression ◽  
Receptor Gene ◽  
Mrna Level ◽  
Experimental Period ◽  
Receptor Expression ◽  
Mrna Levels ◽  
Puromycin Aminonucleoside ◽  
Receptor Mrna ◽  
Etb Receptor ◽  
Receptor Gene Expression

This study assessed glomerular endothelin (ET)-1, ET-3, and ET-receptor A and B mRNA levels in puromycin aminonucleoside (PAN)-induced nephrosis. During the nephrotic stage, 8 days after PAN injection, ET-1 and ETB receptor mRNA were elevated by 2.8 +/- 0.8-fold (P < 0.01) and 2.4 +/- 0.9-fold (P < 0.01), respectively, as compared with controls. These mRNA levels decreased to control levels by Day 20, when the nephrosis was in remission. In contrast, glomerular ETA receptor mRNA levels did not change in PAN nephrosis or control rats during the experimental period. ET-3 mRNA was not detected in the glomeruli of PAN nephrosis or control rats. Additionally, plasma ET concentration and glomerular ET production were measured in PAN nephrosis and control rats by radio-immunoassay. Eight days after PAN injection, ET-1 levels in plasma and glomeruli were not significantly altered in rats with PAN-induced nephrosis (glomeruli, 104.68 +/- 16.46 pg/mg of protein versus 98.24 +/- 13.68 pg/mg of protein; plasma, 2.68 +/- 1.10 versus 2.52 +/- 0.98 pg/mL). The administration of methylprednisolone to PAN rats resulted in the rapid disappearance of proteinuria and partially attenuated the increased ET-1 and ETB receptor gene expression in the glomeruli. These data indicate that glomerular ET-1 and ETB receptor expression in PAN nephrosis in increased at the mRNA level and that methylprednisolone treatment results in an attenuated increase.

scholarly journals Exosomal secretion of a psychosis-altered miRNA that regulates glutamate receptor expression is affected by antipsychotics

2019 ◽  
Vol 45 (4) ◽  
pp. 656-665 ◽  
Author(s):  
Stephen K. Amoah ◽  
Brian A. Rodriguez ◽  
Constantine N. Logothetis ◽  
Praveen Chander ◽  
Carl M. Sellgren ◽  
...  
Keyword(s):  
Gene Expression ◽  
Glutamate Receptor ◽  
Receptor Gene ◽  
Cell Communication ◽  
Receptor Expression ◽  
Neuronal Cultures ◽  
Mrna Levels ◽  
Ionotropic Receptor ◽  
History Of ◽  
A Cell

AbstractThe ability of small secretory microvesicles known as exosomes to influence neuronal and glial function via their microRNA (miRNA) cargo has positioned them as a novel and effective method of cell-to-cell communication. However, little is known about the role of exosome-secreted miRNAs in the regulation of glutamate receptor gene expression and their relevance for schizophrenia (SCZ) and bipolar disorder (BD). Using mature miRNA profiling and quantitative real-time PCR (qRT-PCR) in the orbitofrontal cortex (OFC) of SCZ (N = 29; 20 male and 9 female), BD (N = 26; 12 male and 14 female), and unaffected control (N = 25; 21 male and 4 female) subjects, we uncovered that miR-223, an exosome-secreted miRNA that targets glutamate receptors, was increased at the mature miRNA level in the OFC of SCZ and BD patients with positive history of psychosis at the time of death and was inversely associated with deficits in the expression of its targets glutamate ionotropic receptor NMDA-type subunit 2B (GRIN2B) and glutamate ionotropic receptor AMPA-type subunit 2 (GRIA2). Furthermore, changes in miR-223 levels in the OFC were positively and negatively correlated with inflammatory and GABAergic gene expression, respectively. Moreover, miR-223 was found to be enriched in astrocytes and secreted via exosomes, and antipsychotics were shown to control its cellular and exosomal localization in a cell-specific manner. Furthermore, addition of astrocytic exosomes in neuronal cultures resulted in a significant increase in miR-223 expression and a notable reduction in Grin2b and Gria2 mRNA levels, which was strongly inversely associated with miR-223 expression. Lastly, inhibition of astrocytic miR-223 abrogated the exosomal-mediated reduction in neuronal Grin2b expression. Taken together, our results demonstrate that the exosomal secretion of a psychosis-altered and glial-enriched miRNA that controls neuronal gene expression is regulated by antipsychotics.

Parathyroid hormone receptor stimulation induces human adipocyte lipolysis and browning

2021 ◽  
Vol 184 (5) ◽  
pp. 687-697
Author(s):  
Peter Breining ◽  
Steen B Pedersen ◽  
Mads Kjolby ◽  
Jacob B Hansen ◽  
Niels Jessen ◽  
...  
Keyword(s):  
Gene Expression ◽  
Adipose Tissue ◽  
Parathyroid Hormone ◽  
Receptor Gene ◽  
Receptor Expression ◽  
Whole Body ◽  
Brown Adipocyte ◽  
Cell Models ◽  
Receptor Stimulation ◽  
Receptor Gene Expression

Objective Activation of brown adipose tissue is a promising strategy to treat and prevent obesity and obesity-related disorders. Activation of uncoupling protein 1 (UCP1) leads to uncoupled respiration and dissipation of stored energy as heat. Induction of UCP1-rich adipocytes in white adipose tissue, a process known as ‘browning’, serves as an alternative strategy to increase whole body uncoupling capacity. Here, we aim to assess the association between parathyroid hormone (PTH) receptor expression and UCP1 expression in human adipose tissues and to study PTH effects on human white and brown adipocyte lipolysis and UCP1 expression. Design A descriptive study of human neck adipose tissue biopsies substantiated by an interventional study on human neck-derived adipose tissue cell models. Methods Thermogenic markers and PTH receptor gene expression are assessed in human neck adipose tissue biopsies and are related to individual health records. PTH-initiated lipolysis and thermogenic gene induction are assessed in cultured human white and brown adipocyte cell models. PTH receptor involvement is investigated by PTH receptor silencing. Results PTH receptor gene expression correlates with UCP1 gene expression in the deep-neck adipose tissue in humans. In cell models, PTH receptor stimulation increases lipolysis and stimulates gene transcription of multiple thermogenic markers. Silencing of the PTH receptor attenuates the effects of PTH indicating a direct PTH effect via this receptor. Conclusion PTH 1 receptor stimulation by PTH may play a role in human adipose tissue metabolism by affecting lipolysis and thermogenic capacity.

Acute food deprivation and chronic food restriction differentially affect hypothalamic NPY mRNA expression

2003 ◽  
Vol 285 (5) ◽  
pp. R1030-R1036 ◽  
Author(s):  
Sheng Bi ◽  
Benjamin M. Robinson ◽  
Timothy H. Moran
Keyword(s):  
Gene Expression ◽  
Body Weight ◽  
Food Deprivation ◽  
Food Restriction ◽  
Leptin Receptor ◽  
Receptor Gene ◽  
Body Weight Loss ◽  
Receptor Expression ◽  
Mrna Levels ◽  
Chronic Food Restriction

Although acute food deprivation and chronic food restriction both result in body weight loss, they produce different metabolic states. To evaluate how these two treatments affect hypothalamic peptide systems involved in energy homeostasis, we compared patterns of hypothalamic neuropeptide Y (NPY), agouti-related protein (AgRP), proopiomelanocotin (POMC), and leptin receptor gene expression in acutely food-deprived and chronically food-restricted rats. Both acute food deprivation and chronic food restriction reduced body weight and circulating leptin levels and resulted in increased arcuate NPY and decreased arcuate POMC gene expression. Arcuate AgRP mRNA levels were only elevated in acutely deprived rats. NPY gene expression was increased in the compact subregion of the dorsomedial hypothalamus (DMH) in response to chronic food restriction, but not in response to acute food deprivation. Leptin receptor expression was not affected by either treatment. Double in situ hybridization histochemistry revealed that, in contrast to the situation in the arcuate nucleus, NPY and leptin receptor mRNA-expressing neurons were not colocalized in the DMH. Together, these data suggest that arcuate and DMH NPY gene expression are differentially regulated. DMH NPY-expressing neurons do not appear to be under the direct control of leptin signaling.

scholarly journals PDGF ligand and receptor gene expression during repair of arterial injury.

1990 ◽  
Vol 111 (5) ◽  
pp. 2149-2158 ◽  
Author(s):  
M W Majesky ◽  
M A Reidy ◽  
D F Bowen-Pope ◽  
C E Hart ◽  
J N Wilcox ◽  
...  
Keyword(s):  
Gene Expression ◽  
Carotid Artery ◽  
Receptor Gene ◽  
Receptor Expression ◽  
Quiescent State ◽  
Mrna Levels ◽  
Luminal Surface ◽  
Receptor Mrna ◽  
Beta Receptor ◽  
Receptor Gene Expression

Smooth muscle cells (SMC) in rat carotid artery leave the quiescent state and proliferate after balloon catheter injury, but the signals for mitogenesis are not known. In this study, the possibility that cells within damaged arteries produce a growth factor that could act locally to stimulate SMC replication and repair was examined. We found that the genes for PDGF-A and -B (ligand) and PDGF receptor (alpha and beta subunits) were expressed in normal and injured carotid arteries and were independently regulated during repair of carotid injury. Two phases of PDGF ligand and receptor gene expression were observed: (a) In the early stage, a large decrease in PDGF beta-receptor mRNA levels preceded 10- to 12-fold increases in PDGF-A transcript abundance in the first 6 h after wounding. No change in PDGF alpha-receptor or PDGF-B gene expression was found at these times. (b) In the chronic phase, 2 wk after injury, neointimal tissue had lower levels of PDGF alpha-receptor mRNA (threefold) and higher levels of PDGF beta-receptor mRNA (three- to fivefold) than did restored media. Moreover, in situ hybridization studies identified a subpopulation of neointimal SMC localized at or near the luminal surface with a different pattern of gene expression than the underlying carotid SMC. Luminal SMC were strongly positive for PDGF-A and PDGF beta-receptor transcripts, while showing little or no hybridization for PDGF-B or PDGF alpha-receptor. Immunohistochemical studies showed strongly positive staining for PDGF-A in SMC along the luminal surface. These data show that changes in PDGF ligand and receptor expression occur at specific times and locations in injured carotid artery and suggest that these changes may play a role in regulating arterial wound repair.

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