Corticotropin-Releasing Factor Differentially Regulates Anterior and Intermediate Pituitary Lobe Proopiomelanocortin Gene Transcription, Nuclear Precursor RNA and Mature mRNA in vivo

Autelitano, Dominic J.; Blum, Mariann; Lopingco, M. C.; Allen, Richard B.; Roberts, James L.

doi:10.1159/000125327

Cited by 76 publications

(34 citation statements)

References 28 publications

(71 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We demonstrated that the intrahippocampal injection of hIL-1β induces at the AP level, a concomitant stimulation of the rate of the POMC nuclear primary transcript. As the accumulation of the POMC primary nuclear RNA transcript and POMC gene transcription in the AP, assessed by nuclear run-on transcription are correlated closely [30, 31]; this increase in POMC nuclear primary transcript RNA measured by using an exon/intron junction probe, most likely reflects an increase in POMC gene transcription. We observed a similar increase in the AP POMC nuclear intermediate processing RNA transcript after hIL-1β injection.…”

Section: Discussionmentioning

confidence: 99%

Acute Intrahippocampal Injection of Human Interleukin-1β Stimulates the Anterior Pituitary POMC Transcription and Increases Plasma Levels of ACTH and Corticosterone in the Male Rat

et al. 1999

View full text Add to dashboard Cite

It has been well documented that interleukin-1β (IL-1β) is a major mediator for recruiting the hypothalamo-pituitary-adrenal (HPA) axis following infectious disease. The recent localization of IL-1β receptors in neurons of the hippocampus provides further support for the role of IL-1β as a neurotransmitter/neuromodulator in the central nervous system. In this study, we investigated whether an acute intrahippocampal injection of IL-1β is able to rapidly stimulate HPA activity. Seven days after bilateral implantation of a guide cannula into the hippocampus, human IL-1β (10 ng/0.5 µl/side) was injected to freely moving male rats. Following this, animals were sacrificed at times 20, 45 and 90 min postinjection and a kinetic analysis of hIL-1β action on plasma ACTH and corticosterone (CORT) concentrations and nuclear processing of the anterior pituitary (AP) proopiomelanocortin (POMC) was conducted. Intrahippocampal administration of hIL-1β significantly increased both plasma ACTH and CORT concentrations at 45 and 90 min postinjection. This increase in ACTH concentration paralleled a rise in AP POMC gene transcription. Moreover, the increase in AP POMC primary transcript was followed by an increase in AP POMC intermediate processing RNA. However, at these times, no significant hIL-1β effect on the level of AP nuclear POMC mRNA was observed. Almost identical results were obtained after intraperitoneal injection of hIL-1β. In conclusion, our data demonstrates that the hippocampal IL-1β/IL-1β receptor is directly and rapidly implicated in HPA activation, in the same manner as that observed after intraperitoneal administration of hIL-1β. These results show that IL-1 action in the hippocampus could be of immunoneuroendocrine significance for the HPA axis activation during inflammatory states.

show abstract

Section: Discussionmentioning

confidence: 99%

Acute Intrahippocampal Injection of Human Interleukin-1β Stimulates the Anterior Pituitary POMC Transcription and Increases Plasma Levels of ACTH and Corticosterone in the Male Rat

et al. 1999

View full text Add to dashboard Cite

show abstract

“…Total RNA was quantified by spectrophotometry. Nuclear pellets were washed in 1 ml AT buffer containing 0.3 M sucrose and resuspended in 250 µl of DNase buffer (50 m M Tris-HCl pH 8, 5 m M MgCl 2 , 1 m M MnCl 2 , 1 m M DTT [33]. Nuclei from two MBH disections were pooled, treated with 80 U RNase-free DNase I (Promega, Madison, Wisc., USA) for 5 min at 37°C, and proteinase K for 1 h at 45°C.…”

Section: Methodsmentioning

confidence: 99%

“…Protected bands were quantified either by visualization with an autoradiogram followed by excision of the bands from the gel and liquid scintillation counting, or phosphoimager analysis and comparison with the standard curve. Since the protected hybrids are smaller than the cellular transcripts, samples were corrected for the full-length RNA species: 1.1 kilobase (kb) for full-length POMC cytoplasmic RNA [33], and 6 kb for POMC primary transcript [35]. Results are presented as pg POMC cytoplasmic RNA/µg total RNA or pg POMC hnRNA/MBH.…”

Section: Methodsmentioning

confidence: 99%

Regulation of Hypothalamic Proopiomelanocortin by Leptin in Lean and Obese Rats

Körner¹,

Chua²,

Williams³

et al. 1999

Neuroendocrinology

View full text Add to dashboard Cite

The mechanisms by which leptin influences energy homeostasis are not entirely understood. Several observations indicate that proopiomelanocortin (POMC) is involved in the regulation of food intake and may be a mediator of leptin action. To further study this interaction, a sensitive solution hybridization assay was used to compare the levels of POMC mRNA in the medial basal hypothalamus (MBH) of lean (+/+, +/fa^f) and obese leptin receptor-deficient (fa^f/fa^f) rats. POMC peptide products were also measured by RIA in the same animals. Cytoplasmic POMC RNA levels were significantly reduced by 53% in obese rats as compared with lean controls: 0.30 ± 0.04 vs. 0.64 ± 0.07 pg/µg total RNA (p < 0.02). Significant reductions in mean concentrations of hypothalamic POMC-derived peptides from the same dissections were detected in the obese rats vs. lean controls: α-MSH 1.77 ± 0.07 vs. 2.34 ± 0.10; β-EP 4.06 ± 0.24 vs. 5.86 ± 0.36; γ₃-MSH 5.32 ± 0.20 vs. 6.52 ± 0.12 ng/mg protein (p < 0.001). To determine whether leptin stimulates POMC gene transcription, the acute effect of an intracerebroventricular (i.c.v.) injection of leptin (5 µg) on POMC primary transcript was quantified in the MBH of lean rats after a 16-hour fast. There was a significant 167% increase in mean POMC hnRNA levels 3 h after i.c.v. leptin injection (1.15 ± 0.22 pg/MBH; p < 0.02), but not after 1 h (0.76 ± 0.08 pg/MBH), compared to saline controls (0.69 ± 0.08 pg/MBH). 4 h after the injection of leptin, POMC hnRNA was still increased, but to a lesser extent (140%), as compared with control animals (p = 0.006). These studies demonstrate for the first time in the leptin receptor-deficient rat that there is an associated decrease in POMC gene expression and peptide levels in the MBH. Furthermore, the acute increase in the levels of POMC primary transcript in non-obese rats after a single i.c.v. injection of leptin supports a role for leptin in the regulation of POMC gene transcription. Taken together, these studies provide further evidence that POMC is an important mediator of the effects of leptin on food intake and energy expenditure.

show abstract

“…Several authors suggested that corticotrophin-releasing hormone (CRH) plays the major role in the regulation of pituitary corticotrophs activity [5][6][7]. However, according to others [8][9][10], ACTH response to stress is dependent on the interaction of both, CRH and VP secretion.…”

Section: Introductionmentioning

confidence: 99%

The effect of acute heat exposure on rat pituitary corticotroph activation: the role of vasopressin.

Jasnić

Korać²,

Veličković³

et al. 2011

Folia Histochem Cytobiol.

View full text Add to dashboard Cite

Abstract:The increased ambient temperature affects the function of hypothalamic-pituitary-adrenal (HPA) axis. Since the correlation among vasopressin (VP), adrenocorticotropic hormone (ACTH) and corticosterone (CORT) responses to various stressors have been long recognized, the aim of this study was to reveal the aforementioned hormones production and morphology of the pituitary gland after exposure to acute heat. Rats were exposed to high ambient temperature (38°C) for 20 or 60 minutes. The circulating hormones were determined by an ELISA test or chemiluminescence's method. The results obtained show the elevation in ACTH and CORT secretion depending on the duration of heat exposure. The VP concentration increased only after prolonged exposure to heat (60 min). The pituitary morphology was examined by routine and fluorescent immunohistochemistry as well as electron microscopy. Observed changes in the anterior and posterior pituitary well corresponded to circulating hormones, regarding the volume density of ACTH-immunopositive cells, percentage of ACTH immunopositive area v. total area and number of VP-immunopositive containing varicose fibers per total area. Acute heat exposure also induced changes in shapes of ACTH-immunopositive cells. Cells appeared stellate with numerous slender cytoplasmic processes and degranulated, which is the most obvious after 20 min. In addition, immunopositivity of endothelial and anterior pituitary cells for VP suggests its influence on ACTH secretion.

show abstract

Corticotropin-Releasing Factor Differentially Regulates Anterior and Intermediate Pituitary Lobe Proopiomelanocortin Gene Transcription, Nuclear Precursor RNA and Mature mRNA in vivo

Cited by 76 publications

References 28 publications

Acute Intrahippocampal Injection of Human Interleukin-1β Stimulates the Anterior Pituitary POMC Transcription and Increases Plasma Levels of ACTH and Corticosterone in the Male Rat

Acute Intrahippocampal Injection of Human Interleukin-1β Stimulates the Anterior Pituitary POMC Transcription and Increases Plasma Levels of ACTH and Corticosterone in the Male Rat

Regulation of Hypothalamic Proopiomelanocortin by Leptin in Lean and Obese Rats

The effect of acute heat exposure on rat pituitary corticotroph activation: the role of vasopressin.

Contact Info

Product

Resources

About