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SAT601 The Role Of The Melanocortin System In Ovine Puberty

Disclosure: E.G. Aerts: None. M.J. Griesgraber: None. A. Thomson: None. M. Brown: None. A. Seman: None. S.L. Hardy: None. R.L. Goodman: None. C. Nestor: None. S.M. Hileman: None. The neural mechanisms that regulate the timing of puberty onset are not completely known. In several species, including s...

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Autores principales: Aerts, Eliana G, Griesgraber, Max J, Thomson, Ashleigh, Brown, Malori, Seman, Andrew, Bowdridge, Elizabeth, Hardy, Steven L, Goodman, Robert L, Nestor, Casey, Hileman, Stanley M
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Oxford University Press 2023
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10554578/
http://dx.doi.org/10.1210/jendso/bvad114.1334
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author Aerts, Eliana G
Griesgraber, Max J
Thomson, Ashleigh
Brown, Malori
Seman, Andrew
Bowdridge, Elizabeth
Hardy, Steven L
Goodman, Robert L
Nestor, Casey
Hileman, Stanley M
author_facet Aerts, Eliana G
Griesgraber, Max J
Thomson, Ashleigh
Brown, Malori
Seman, Andrew
Bowdridge, Elizabeth
Hardy, Steven L
Goodman, Robert L
Nestor, Casey
Hileman, Stanley M
author_sort Aerts, Eliana G
collection PubMed
description Disclosure: E.G. Aerts: None. M.J. Griesgraber: None. A. Thomson: None. M. Brown: None. A. Seman: None. S.L. Hardy: None. R.L. Goodman: None. C. Nestor: None. S.M. Hileman: None. The neural mechanisms that regulate the timing of puberty onset are not completely known. In several species, including sheep, puberty onset relies on an increase in gonadotropin-releasing hormone (GnRH) and luteinizing hormone (LH) secretion as a result of decreased sensitivity to estradiol (E(2)) inhibition. Additionally, it is unclear how E(2) acts in the hypothalamus to inhibit GnRH/LH secretion, as GnRH neurons do not contain estrogen receptor alpha (ERα). Neurons within the arcuate nucleus (ARC) of the hypothalamus that contain kisspeptin, neurokinin B, and dynorphin (KNDy neurons) are critical for the generation of GnRH pulses and contain ERα. Data from our laboratory suggests that KNDy neurons, while critical, may be responding to other inputs that time puberty onset. Proopiomelanocortin (POMC) and Agouti-related peptide (AgRP) neurons in the ARC have been shown to contain ERα and provide input to KNDy neurons, which contain the melanocortin 3 and 4 receptor (MC3R, MC4R). The goal of this work was to assess POMC- and AgRP-positive cell numbers, input onto KNDy neurons, and neuronal activity changes in a puberty-specific manner. Female sheep were ovariectomized and given subcutaneous E(2) implants at 5 months (prepubertal, n=4), 8 months (peripubertal, n=5), and 10 months (postpubertal, n=5) of age. Two weeks after surgery, blood samples were collected via jugular venipuncture every 12 minutes for 4 hours and assessed for LH. The sheep were then sacrificed and hypothalamic tissue was perfused, collected, and prepared for staining. The tissue was assessed via immunohistochemistry for POMC, AgRP, kisspeptin, NKB, and c-Fos, a known marker of neuronal activity. Pulsatile LH secretion was, as expected, reduced at 5 months and highest at 10 months. ARC POMC cell numbers did not significantly change over development (p>0.10). The number of ARC POMC close contacts onto ARC kisspeptin neurons increased significantly with development (p<0.05), as well as the percentage of ARC POMC neurons expressing c-Fos (p<0.05). ARC AgRP cell numbers and the percentage of AgRP cells colocalized with c-Fos decreased significantly over time (p<0.05). The number of AgRP close contacts onto ARC NKB cells is currently being analyzed. The percentage of NKB cells colocalizing c-Fos throughout pubertal development also increased significantly (p<0.05). This data supports the hypothesis that the ARC melanocortin system impacts KNDy neurons to regulate GnRH/LH secretion throughout pubertal development. Presentation: Saturday, June 17, 2023
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spelling pubmed-105545782023-10-06 SAT601 The Role Of The Melanocortin System In Ovine Puberty Aerts, Eliana G Griesgraber, Max J Thomson, Ashleigh Brown, Malori Seman, Andrew Bowdridge, Elizabeth Hardy, Steven L Goodman, Robert L Nestor, Casey Hileman, Stanley M J Endocr Soc Neuroendocrinology And Pituitary Disclosure: E.G. Aerts: None. M.J. Griesgraber: None. A. Thomson: None. M. Brown: None. A. Seman: None. S.L. Hardy: None. R.L. Goodman: None. C. Nestor: None. S.M. Hileman: None. The neural mechanisms that regulate the timing of puberty onset are not completely known. In several species, including sheep, puberty onset relies on an increase in gonadotropin-releasing hormone (GnRH) and luteinizing hormone (LH) secretion as a result of decreased sensitivity to estradiol (E(2)) inhibition. Additionally, it is unclear how E(2) acts in the hypothalamus to inhibit GnRH/LH secretion, as GnRH neurons do not contain estrogen receptor alpha (ERα). Neurons within the arcuate nucleus (ARC) of the hypothalamus that contain kisspeptin, neurokinin B, and dynorphin (KNDy neurons) are critical for the generation of GnRH pulses and contain ERα. Data from our laboratory suggests that KNDy neurons, while critical, may be responding to other inputs that time puberty onset. Proopiomelanocortin (POMC) and Agouti-related peptide (AgRP) neurons in the ARC have been shown to contain ERα and provide input to KNDy neurons, which contain the melanocortin 3 and 4 receptor (MC3R, MC4R). The goal of this work was to assess POMC- and AgRP-positive cell numbers, input onto KNDy neurons, and neuronal activity changes in a puberty-specific manner. Female sheep were ovariectomized and given subcutaneous E(2) implants at 5 months (prepubertal, n=4), 8 months (peripubertal, n=5), and 10 months (postpubertal, n=5) of age. Two weeks after surgery, blood samples were collected via jugular venipuncture every 12 minutes for 4 hours and assessed for LH. The sheep were then sacrificed and hypothalamic tissue was perfused, collected, and prepared for staining. The tissue was assessed via immunohistochemistry for POMC, AgRP, kisspeptin, NKB, and c-Fos, a known marker of neuronal activity. Pulsatile LH secretion was, as expected, reduced at 5 months and highest at 10 months. ARC POMC cell numbers did not significantly change over development (p>0.10). The number of ARC POMC close contacts onto ARC kisspeptin neurons increased significantly with development (p<0.05), as well as the percentage of ARC POMC neurons expressing c-Fos (p<0.05). ARC AgRP cell numbers and the percentage of AgRP cells colocalized with c-Fos decreased significantly over time (p<0.05). The number of AgRP close contacts onto ARC NKB cells is currently being analyzed. The percentage of NKB cells colocalizing c-Fos throughout pubertal development also increased significantly (p<0.05). This data supports the hypothesis that the ARC melanocortin system impacts KNDy neurons to regulate GnRH/LH secretion throughout pubertal development. Presentation: Saturday, June 17, 2023 Oxford University Press 2023-10-05 /pmc/articles/PMC10554578/ http://dx.doi.org/10.1210/jendso/bvad114.1334 Text en © The Author(s) 2023. Published by Oxford University Press on behalf of the Endocrine Society. https://creativecommons.org/licenses/by-nc-nd/4.0/This is an Open Access article distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs licence (https://creativecommons.org/licenses/by-nc-nd/4.0/), which permits non-commercial reproduction and distribution of the work, in any medium, provided the original work is not altered or transformed in any way, and that the work is properly cited. For commercial re-use, please contact journals.permissions@oup.com
spellingShingle Neuroendocrinology And Pituitary
Aerts, Eliana G
Griesgraber, Max J
Thomson, Ashleigh
Brown, Malori
Seman, Andrew
Bowdridge, Elizabeth
Hardy, Steven L
Goodman, Robert L
Nestor, Casey
Hileman, Stanley M
SAT601 The Role Of The Melanocortin System In Ovine Puberty
title SAT601 The Role Of The Melanocortin System In Ovine Puberty
title_full SAT601 The Role Of The Melanocortin System In Ovine Puberty
title_fullStr SAT601 The Role Of The Melanocortin System In Ovine Puberty
title_full_unstemmed SAT601 The Role Of The Melanocortin System In Ovine Puberty
title_short SAT601 The Role Of The Melanocortin System In Ovine Puberty
title_sort sat601 the role of the melanocortin system in ovine puberty
topic Neuroendocrinology And Pituitary
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10554578/
http://dx.doi.org/10.1210/jendso/bvad114.1334
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