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Gao Q, Xie W, Lu W, Liu Y, Zhang H, Han Y, Weng Q. Seasonal patterns of prolactin, prolactin receptor, and STAT5 expression in the ovaries of wild ground squirrels (<em>Citellus dauricus</em> Brandt). Eur J Histochem 2023; 67:3825. [PMID: 37781865 PMCID: PMC10614723 DOI: 10.4081/ejh.2023.3825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Accepted: 08/30/2023] [Indexed: 10/03/2023] Open
Abstract
Prolactin (PRL) is a hormone crucial for normal reproduction, functioning as an autocrine, paracrine, and endocrine factor. This study aimed to examine the immunolocalization and expression patterns of PRL, prolactin receptor (PRLR), and signal transducer and activator of transcription 5 (STAT5) in the ovaries of wild ground squirrels during both breeding and non-breeding periods. Significant seasonal variations were observed in ovarian weights, with higher values during the breeding season and relatively lower values during the nonbreeding season. PRL, PRLR, STAT5, and p-STAT5 were immunolocalized in granulosa cells and luteal cells during the breeding season, whereas they were exclusively found in granulosa cells during the non-breeding season. The mRNA expression levels of Prl, Prlr, and Stat5 were increased in ovarian tissues during the breeding season compared to the non-breeding season. Moreover, the mean mRNA levels of Prl, Prlr, and Stat5 exhibited a positive correlation with ovarian weights. Both circulating PRL and ovarian PRL concentrations were significantly elevated during the breeding season. Additionally, transcriptomic analysis of ovarian tissues revealed differentially expressed genes possibly associated with ovarian function and mammary gland development, including ovarian follicle development, steroid synthesis, and regulation of reproductive process. These findings suggest that PRL might play an essential endocrine, autocrine, or paracrine role in the regulation of seasonal changes in the ovarian functions in wild ground squirrels.
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Affiliation(s)
- Qingjing Gao
- Laboratory of Animal Physiology, College of Biological Sciences and Technology, Beijing Forestry University, Beijing.
| | - Wenqian Xie
- Laboratory of Animal Physiology, College of Biological Sciences and Technology, Beijing Forestry University, Beijing.
| | - Wenjing Lu
- Laboratory of Animal Physiology, College of Biological Sciences and Technology, Beijing Forestry University, Beijing.
| | - Yuning Liu
- Laboratory of Animal Physiology, College of Biological Sciences and Technology, Beijing Forestry University, Beijing.
| | - Haolin Zhang
- Laboratory of Animal Physiology, College of Biological Sciences and Technology, Beijing Forestry University, Beijing.
| | - Yingying Han
- Laboratory of Animal Physiology, College of Biological Sciences and Technology, Beijing Forestry University, Beijing.
| | - Qiang Weng
- Laboratory of Animal Physiology, College of Biological Sciences and Technology, Beijing Forestry University, Beijing.
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Cortasa SA, Inserra PFI, Proietto S, Corso MC, Schmidt AR, Vitullo AD, Dorfman VB, Halperin J. Achieving full-term pregnancy in the vizcacha relies on a reboot of luteal steroidogenesis in mid-gestation (Lagostomus maximus, Rodentia). PLoS One 2022; 17:e0271067. [PMID: 35802690 PMCID: PMC9269958 DOI: 10.1371/journal.pone.0271067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Accepted: 06/22/2022] [Indexed: 11/19/2022] Open
Abstract
Reactivation of the hypothalamic-pituitary-ovarian (HPO) axis triggered by the decline in serum progesterone in mid-gestation is an uncommon trait that distinguishes the vizcacha from most mammals. Accessory corpora lutea (aCL) developed upon this event have been proposed as guarantors of the restoration of the progesterone levels necessary to mantain gestation. Therefore, the steroidogenic input of primary CL (pCL) vs aCL was evaluated before and after HPO axis-reactivation (BP and AP respectively) and in term pregnancy (TP). Nonpregnant-ovulated females (NP) were considered as the pCL-starting point group. In BP, the ovaries mainly showed pCL, whose LH receptor (LHR), StAR, 3β-HSD, 20α-HSD, and VEGF immunoexpressions were similar or lower than those of NP. In AP, luteal reactivity increased significantly compared to the previous stages, and the pool of aCL developed in this stage represented 20% of the ovarian structures, equaling the percentage of pCL. Both pCL and aCL luteal cells shared similar histological features consistent with secretory activity. Although pCL and aCL showed equivalent labeling intensity for the luteotropic markers, pCL were significantly larger than aCL. Towards TP, both showed structural disorganization and loss of secretory characteristics. No significant DNA fragmentation was detected in luteal cells throughout gestation. Our findings indicate that the LH surge derived from HPO axis-reactivation targets the pCL and boost luteal steroidogenesis and thus progesterone production. Because there are many LHR-expressing antral follicles in BP, they also respond to the LH stimuli and luteinize without extruding the oocyte. These aCL certainly contribute but it is the steroidogenic restart of the pCL that is the main force that restores progesterone levels, ensuring that gestation is carried to term. Most importantly, the results of this work propose luteal steroidogenesis reboot as a key event in the modulation of vizcacha pregnancy and depict yet another distinctive aspect of its reproductive endocrinology.
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Affiliation(s)
- Santiago Andrés Cortasa
- Centro de Estudios Biomédicos Básicos, Aplicados y Desarrollo (CEBBAD) Universidad Maimónides, Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Pablo Felipe Ignacio Inserra
- Centro de Estudios Biomédicos Básicos, Aplicados y Desarrollo (CEBBAD) Universidad Maimónides, Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Sofía Proietto
- Centro de Estudios Biomédicos Básicos, Aplicados y Desarrollo (CEBBAD) Universidad Maimónides, Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - María Clara Corso
- Centro de Estudios Biomédicos Básicos, Aplicados y Desarrollo (CEBBAD) Universidad Maimónides, Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Alejandro Raúl Schmidt
- Centro de Estudios Biomédicos Básicos, Aplicados y Desarrollo (CEBBAD) Universidad Maimónides, Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Alfredo Daniel Vitullo
- Centro de Estudios Biomédicos Básicos, Aplicados y Desarrollo (CEBBAD) Universidad Maimónides, Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Verónica Berta Dorfman
- Centro de Estudios Biomédicos Básicos, Aplicados y Desarrollo (CEBBAD) Universidad Maimónides, Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Julia Halperin
- Centro de Estudios Biomédicos Básicos, Aplicados y Desarrollo (CEBBAD) Universidad Maimónides, Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
- * E-mail:
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Nappi RE, Di Ciaccio S, Genazzani AD. Prolactin as a neuroendocrine clue in sexual function of women across the reproductive life cycle: an expert point of view. Gynecol Endocrinol 2021; 37:490-496. [PMID: 33703987 DOI: 10.1080/09513590.2021.1897783] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Prolactin is a proteic hormone best known for its role in enabling the production of milk by female mammals. Secreted by the pituitary gland in response to the stimuli of eating, estrogen treatment, mating, ovulation and nursing, prolactin is involved in over 300 separate processes in a range of vertebrates, including humans. The hormone is released in a pulsatile manner and plays an essential role in metabolism, as well as in the regulation of the immune system and pancreatic development. Nevertheless, prolactin exerts other relevant roles, as it acts at the central nervous system level to modulate behavior, arousal and sexuality. In this experts' opinion, we aim to give insights into the main activities of prolactin to advance the ability of medical doctors and specialists in obstetrics and gynecology to provide more emphasis in their clinical practices to the link between prolactin and sexuality.
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Affiliation(s)
- Rossella E Nappi
- Research Center for Reproductive Medicine, Gynecological Endocrinology and Menopause, IRCCS San Matteo Foundation, Department of Clinical, Surgical, Diagnostic and Pediatric Sciences, University of Pavia, Pavia, Italy
| | | | - Alessandro D Genazzani
- Gynecological Endocrinology Center, Department of Obstetrics and Gynecology, University of Modena and Reggio Emilia, Modena, Italy
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Proietto S, Cortasa SA, Corso MC, Inserra PIF, Charif SE, Schmidt AR, Di Giorgio NP, Lux-Lantos V, Vitullo AD, Dorfman VB, Halperin J. Prolactin Is a Strong Candidate for the Regulation of Luteal Steroidogenesis in Vizcachas ( Lagostomus maximus). Int J Endocrinol 2018; 2018:1910672. [PMID: 30013596 PMCID: PMC6022330 DOI: 10.1155/2018/1910672] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/30/2017] [Revised: 04/20/2018] [Accepted: 05/07/2018] [Indexed: 12/11/2022] Open
Abstract
Prolactin (PRL) is essential for the maintenance of the corpora lutea and the production of progesterone (P4) during gestation of mice and rats, which makes it a key factor for their successful reproduction. Unlike these rodents and the vast majority of mammals, female vizcachas (Lagostomus maximus) have a peculiar reproductive biology characterized by an ovulatory event during pregnancy that generates secondary corpora lutea with a consequent increment of the circulating P4. We found that, although the expression of pituitary PRL increased steadily during pregnancy, its ovarian receptor (PRLR) reached its maximum in midpregnancy and drastically decreased at term pregnancy. The luteinizing hormone receptor (LHR) exhibited a similar profile than PRLR. Maximum P4 and LH blood levels were recorded at midpregnancy as well. Remarkably, the P4-sinthesizing enzyme 3β-HSD accompanied the expression pattern of PRLR/LHR throughout gestation. Instead, the luteolytic enzyme 20α-HSD showed low expression at early and midpregnancy, but reached its maximum at the end of gestation, when PRLR/LHR/3ß-HSD expressions and circulating P4 were minimal. In conclusion, both the PRLR and LHR expressions in the ovary would define the success of gestation in vizcachas by modulating the levels of 20α-HSD and 3ß-HSD, which ultimately determine the level of serum P4 throughout gestation.
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Affiliation(s)
- S. Proietto
- Centro de Estudios Biomédicos, Biotecnológicos, Ambientales y Diagnóstico (CEBBAD), Universidad Maimónides, Ciudad Autónoma de Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - S. A. Cortasa
- Centro de Estudios Biomédicos, Biotecnológicos, Ambientales y Diagnóstico (CEBBAD), Universidad Maimónides, Ciudad Autónoma de Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - M. C. Corso
- Centro de Estudios Biomédicos, Biotecnológicos, Ambientales y Diagnóstico (CEBBAD), Universidad Maimónides, Ciudad Autónoma de Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - P. I. F. Inserra
- Centro de Estudios Biomédicos, Biotecnológicos, Ambientales y Diagnóstico (CEBBAD), Universidad Maimónides, Ciudad Autónoma de Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - S. E. Charif
- Centro de Estudios Biomédicos, Biotecnológicos, Ambientales y Diagnóstico (CEBBAD), Universidad Maimónides, Ciudad Autónoma de Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - A. R. Schmidt
- Centro de Estudios Biomédicos, Biotecnológicos, Ambientales y Diagnóstico (CEBBAD), Universidad Maimónides, Ciudad Autónoma de Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - N. P. Di Giorgio
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
- Laboratorio de Neuroendocrinología, Instituto de Biología y Medicina Experimental (IByME), Ciudad Autónoma de Buenos Aires, Argentina
| | - V. Lux-Lantos
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
- Laboratorio de Neuroendocrinología, Instituto de Biología y Medicina Experimental (IByME), Ciudad Autónoma de Buenos Aires, Argentina
| | - A. D. Vitullo
- Centro de Estudios Biomédicos, Biotecnológicos, Ambientales y Diagnóstico (CEBBAD), Universidad Maimónides, Ciudad Autónoma de Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - V. B. Dorfman
- Centro de Estudios Biomédicos, Biotecnológicos, Ambientales y Diagnóstico (CEBBAD), Universidad Maimónides, Ciudad Autónoma de Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - J. Halperin
- Centro de Estudios Biomédicos, Biotecnológicos, Ambientales y Diagnóstico (CEBBAD), Universidad Maimónides, Ciudad Autónoma de Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
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Ratner LD, Gonzalez B, Ahtiainen P, Di Giorgio NP, Poutanen M, Calandra RS, Huhtaniemi IT, Rulli SB. Short-term pharmacological suppression of the hyperprolactinemia of infertile hCG-overproducing female mice persistently restores their fertility. Endocrinology 2012; 153:5980-92. [PMID: 23117930 PMCID: PMC3544356 DOI: 10.1210/en.2012-1393] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Female infertility is often associated with deregulation of hormonal networks, and hyperprolactinemia is one of the most common endocrine disorders of the hypothalamic-pituitary axis affecting the reproductive functions. We have shown previously that transgenic female mice overexpressing human chorionic gonadotropin β-subunit (hCGβ+ mice), and producing elevated levels of bioactive LH/hCG, exhibit increased production of testosterone and progesterone, are overweight and infertile, and develop hyperprolactinemia associated with pituitary lactotrope adenomas in adult age. In the present study, we analyzed the influence of the hyperprolactinemia of hCGβ+ females on their reproductive phenotype by treating them with the dopamine agonists, bromocriptine and cabergoline. Long-term bromocriptine treatment of adult mice was effective in the control of obesity, pituitary growth, and disturbances in the hormone profile, demonstrating that hyperprolactinemia was the main cause of the hCGβ+ female phenotype. Interestingly, short-term treatment (1 wk) with cabergoline applied on 5-wk-old mice corrected hyperprolactinemia, hyperandrogenism, and hyperprogesteronemia, prevented pituitary overgrowth, normalized gonadal function, and recovered fertility of adult hCGβ+ females after hormone-induced and natural ovulation. The same cabergoline treatment in the short term applied on 3-month-old hCGβ+ females failed to recover their reproductive function. Hence, we demonstrated that the short-term cabergoline treatment applied at a critical early stage of the phenotype progression effectively prevented the hyperprolactinemia-associated reproductive dysfunction of hCG-overproducing females.
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Affiliation(s)
- Laura D Ratner
- Instituto de Biología y Medicina Experimental-Consejo Nacional de Investigaciones Científicas y Técnicas, Vuelta de Obligado 2490, C1428ADN Buenos Aires, Argentina
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Chen J, Liu H, Cai Y, Wang G, Liu H, Li J. Mutations in the exon 10 of prolactin receptor gene change the egg production performance in Wanjiang white goose. Mol Biol Rep 2011; 39:475-83. [PMID: 21559838 DOI: 10.1007/s11033-011-0761-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2010] [Accepted: 04/27/2011] [Indexed: 01/28/2023]
Abstract
To select the molecular genetic markers related to egg performance of Wanjiang white goose, prolactin receptor gene (PRLR) was adopted to be a candidate gene in our study. Five pairs of primers (P1-P5) were designed to detect the SNPs of PRLR gene by PCR-SSCP method. The results revealed that polymorphisms were discovered in the PCR products amplified with P4 primers in PRLR exon 10, three genotypes were found: AA, AB and AC. The sequence of AB genotype is the same as original sequence (DQ660982) in NCBI. There are five mutations in AA genotype: C→A at 840 bp, C→T at 862 bp, T→C at 875 bp, T→A at 963 bp, A→T at 989 bp, resulting in amino acid mutations: His→Asn, Thr→Ile, Asn→Lys, Thr→Ser, and synonymous mutation at 875 bp. Sequencing revealed five mutations in AC genotype: G→T at 816 bp, A→T at 861 bp, C→T at 862 bp, T→C at 875 bp, A→G at 948 bp, causing amino acid mutations of Val→Phe, Thr→Phe, synonymous mutations at 875 and 963 bp. Besides, there are an N-glycosylation site (NQSR), three casein kinase II phosphorylation sites including SIIE, SKTE, and SLMD in AA genotype; three casein kinase II phosphorylation sites including SIIE, SKTE, and TLMD in AB genotype; three casein kinase II phosphorylation sites including SIFE, SKTE, and TLMD in AC genotype. The annual egg yielding of AB genotype geese are significantly more than those of AA and AC genotype geese on the average (P<0.05). It is suggested for the first time that PRLR is a promising candidate gene that can affect egg performance in Wanjiang white goose.
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Affiliation(s)
- Jie Chen
- College of Life Sciences, Anhui Normal University, Wuhu, 241000, China
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Physiologie der Lutealphase. GYNAKOLOGISCHE ENDOKRINOLOGIE 2008. [DOI: 10.1007/s10304-008-0272-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Goyeneche AA, Telleria CM. Exogenous estradiol enhances apoptosis in regressing post-partum rat corpora lutea possibly mediated by prolactin. Reprod Biol Endocrinol 2005; 3:40. [PMID: 16131396 PMCID: PMC1236958 DOI: 10.1186/1477-7827-3-40] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2005] [Accepted: 08/30/2005] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND In pregnant rats, structural luteal regression takes place after parturition and is associated with cell death by apoptosis. We have recently shown that the hormonal environment is responsible for the fate of the corpora lutea (CL). Changing the levels of circulating hormones in post-partum rats, either by injecting androgen, progesterone, or by allowing dams to suckle, was coupled with a delay in the onset of apoptosis in the CL. The objectives of the present investigation were: i) to examine the effect of exogenous estradiol on apoptosis of the rat CL during post-partum luteal regression; and ii) to evaluate the post-partum luteal expression of the estrogen receptor (ER) genes. METHODS In a first experiment, rats after parturition were separated from their pups and injected daily with vehicle or estradiol benzoate for 4 days. On day 4 post-partum, animals were sacrificed, blood samples were taken to determine serum concentrations of hormones, and the ovaries were isolated to study apoptosis in situ. In a second experiment, non-lactating rats after parturition received vehicle, estradiol benzoate or estradiol benzoate plus bromoergocryptine for 4 days, and their CL were isolated and used to study apoptosis ex vivo. In a third experiment, we obtained CL from rats on day 15 of pregnancy and from non-lactating rats on day 4 post-partum, and studied the expression of the messenger RNAs (mRNAs) encoding the ERalpha and ERbeta genes. RESULTS Exogenous administration of estradiol benzoate induced an increase in the number of apoptotic cells within the CL on day 4 post-partum when compared with animals receiving vehicle alone. Animals treated with the estrogen had higher serum prolactin and progesterone concentrations, with no changes in serum androstenedione. Administration of bromoergocryptine blocked the increase in serum prolactin and progesterone concentrations, and DNA fragmentation induced by the estrogen treatment. ERalpha and ERbeta mRNAs were expressed in CL of day 4 post-partum animals at levels similar to those found in CL of day 15 pregnant animals. CONCLUSION We have established that estradiol accelerates apoptosis in the CL during post-partum luteal regression through a mechanism that possibly involves the secretion of pituitary prolactin. We have also shown that the post-partum rat CL express ERalpha and ERbeta mRNAs suggesting that they can be targeted by estrogen.
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Affiliation(s)
- Alicia A Goyeneche
- Division of Basic Biomedical Sciences, University of South Dakota School of Medicine, Vermillion, South Dakota 57069, USA
| | - Carlos M Telleria
- Division of Basic Biomedical Sciences, University of South Dakota School of Medicine, Vermillion, South Dakota 57069, USA
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Risk M, Shehu A, Mao J, Stocco CO, Goldsmith LT, Bowen-Shauver JM, Gibori G. Cloning and characterization of a 5' regulatory region of the prolactin receptor-associated protein/17{beta} hydroxysteroid dehydrogenase 7 gene. Endocrinology 2005; 146:2807-16. [PMID: 15731358 DOI: 10.1210/en.2004-1673] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Prolactin receptor-associated protein (PRAP) originally cloned in our laboratory was shown to be a novel, luteal isoform of 17beta hydroxysteroid dehydrogenase 7 (17betaHSD7). In this study, we cloned the promoter region of rat PRAP/17betaHSD7 and investigated the mechanisms regulating both basal activity and LH-induced repression of this promoter. Truncated and site-specific mutants of PRAP/17betaHSD7 promoter identified two enhancer regions that contained highly conserved Sp1 binding site and bound Sp1 from nuclear extracts of both corpora lutea and a rat luteal cell line. Repression of PRAP/17betaHSD7 expression and promoter activity by human chorionic gonadotropin/forskolin was localized to a -52-bp proximal segment of the promoter. This region contained a conserved CCAAT site and bound nuclear factor Y; binding of this transcription factor was inhibited by human chorionic gonadotropin in vivo. Furthermore, mutation of the nuclear factor Y site in the -52-bp promoter-reporter construct abolished forskolin-mediated inhibition of the promoter in a rat luteal cell line. In summary, we have identified the promoter elements involved in the basal expression of PRAP/17betaHSD7. We have also found that LH-mediated repression of this gene is at the level of transcription and involves inhibition of nuclear factor YA binding to the CCAAT site within the proximal promoter.
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Affiliation(s)
- Michael Risk
- Department of Physiology and Biophysics, University of Illinois at Chicago, 835 South Wolcott (M/C 901), Chicago, Illinois 60612, USA
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