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Ullah MT, Lopes MBS, Jane JA, Hong GK, Love KM. Co-occurrence of Functional Gonadotroph Adenoma and Lactotroph Adenoma: A Case Report and Literature Review. AACE Clin Case Rep 2022; 9:5-9. [PMID: 36654994 PMCID: PMC9837085 DOI: 10.1016/j.aace.2022.11.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Revised: 10/27/2022] [Accepted: 11/02/2022] [Indexed: 11/08/2022] Open
Abstract
Background/Objective Functional gonadotroph adenomas (FGAs) are adenomas producing active gonadotropins, follicle-stimulating hormone or luteinizing hormone. Double pituitary adenomas are 2 distinct adenomas occurring in an individual. This report aimed to present an extremely rare case of an FGA, itself an uncommon disorder, co-occurring with a lactotroph adenoma. Case Report A 33-year-old woman presented with menorrhagia and was found to have ovarian enlargement, large uterine leiomyomas, and bitemporal hemianopsia. Initially, the levels of follicle-stimulating hormone, luteinizing hormone, estradiol, and prolactin were 73.3 mIU/mL (midcycle peak, 2.3-20.9 mIU/L), 3.74 mIU/L (midcycle peak, 8.7-76.3 mIU/L), 1071 pg/mL (midcycle peak 38-649 pg/mL), and 402 ng/mL (2-30 ng/mL), respectively. Pituitary magnetic resonance imaging demonstrated a single sellar mass (2.0 × 2.2 cm). Two months of cabergoline did not reverse visual field deficits; therefore, transsphenoidal resection was performed. Diagnosis of 2 separate adenomas, a gonadotroph and lactotroph adenoma, was confirmed on pathology. Discussion In this case, gonadotropins did not suppress in response to hyperprolactinemia. Although marked hyperprolactinemia has been associated with functional and clinically silent gonadotroph adenomas in prior cases, this is the first case to confirm an FGA co-occurring with a lactotroph adenoma. Conclusion In patients who present with elevated gonadotropin levels despite hyperprolactinemia, we suggest considering FGA. Further research is needed to clarify whether there is underdiagnosis of lactotroph adenomas co-occurring with gonadotroph adenomas.
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Affiliation(s)
- Mohammad T. Ullah
- Department of Endocrinology and Metabolism, University of Virginia Health System, Charlottesville, Virginia
| | - M. Beatriz S. Lopes
- Department of Pathology and Neurological Surgery, University of Virginia Health System, Charlottesville, Virginia
| | - John A. Jane
- Department of Neurological Surgery, University of Virginia Health System, Charlottesville, Virginia
| | - Gregory K. Hong
- Department of Endocrinology and Metabolism, University of Virginia Health System, Charlottesville, Virginia
| | - Kaitlin M. Love
- Department of Endocrinology and Metabolism, University of Virginia Health System, Charlottesville, Virginia,Address correspondence to Dr Kaitlin M. Love, Department of Endocrinology and Metabolism, University of Virginia Health System, 450 Ray C. Hunt Drive, Box 800136, Charlottesville, VA 22903.
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Xie Y, Su N, Yang J, Tan Q, Huang S, Jin M, Ni Z, Zhang B, Zhang D, Luo F, Chen H, Sun X, Feng JQ, Qi H, Chen L. FGF/FGFR signaling in health and disease. Signal Transduct Target Ther 2020; 5:181. [PMID: 32879300 PMCID: PMC7468161 DOI: 10.1038/s41392-020-00222-7] [Citation(s) in RCA: 310] [Impact Index Per Article: 77.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Revised: 05/28/2020] [Accepted: 06/15/2020] [Indexed: 12/13/2022] Open
Abstract
Growing evidences suggest that the fibroblast growth factor/FGF receptor (FGF/FGFR) signaling has crucial roles in a multitude of processes during embryonic development and adult homeostasis by regulating cellular lineage commitment, differentiation, proliferation, and apoptosis of various types of cells. In this review, we provide a comprehensive overview of the current understanding of FGF signaling and its roles in organ development, injury repair, and the pathophysiology of spectrum of diseases, which is a consequence of FGF signaling dysregulation, including cancers and chronic kidney disease (CKD). In this context, the agonists and antagonists for FGF-FGFRs might have therapeutic benefits in multiple systems.
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Affiliation(s)
- Yangli Xie
- Department of Wound Repair and Rehabilitation Medicine, State Key Laboratory of Trauma, Burns and Combined Injury, Trauma Center, Research Institute of Surgery, Daping Hospital, Army Medical University, Chongqing, China.
| | - Nan Su
- Department of Wound Repair and Rehabilitation Medicine, State Key Laboratory of Trauma, Burns and Combined Injury, Trauma Center, Research Institute of Surgery, Daping Hospital, Army Medical University, Chongqing, China
| | - Jing Yang
- Department of Wound Repair and Rehabilitation Medicine, State Key Laboratory of Trauma, Burns and Combined Injury, Trauma Center, Research Institute of Surgery, Daping Hospital, Army Medical University, Chongqing, China
| | - Qiaoyan Tan
- Department of Wound Repair and Rehabilitation Medicine, State Key Laboratory of Trauma, Burns and Combined Injury, Trauma Center, Research Institute of Surgery, Daping Hospital, Army Medical University, Chongqing, China
| | - Shuo Huang
- Department of Wound Repair and Rehabilitation Medicine, State Key Laboratory of Trauma, Burns and Combined Injury, Trauma Center, Research Institute of Surgery, Daping Hospital, Army Medical University, Chongqing, China
| | - Min Jin
- Department of Wound Repair and Rehabilitation Medicine, State Key Laboratory of Trauma, Burns and Combined Injury, Trauma Center, Research Institute of Surgery, Daping Hospital, Army Medical University, Chongqing, China
| | - Zhenhong Ni
- Department of Wound Repair and Rehabilitation Medicine, State Key Laboratory of Trauma, Burns and Combined Injury, Trauma Center, Research Institute of Surgery, Daping Hospital, Army Medical University, Chongqing, China
| | - Bin Zhang
- Department of Wound Repair and Rehabilitation Medicine, State Key Laboratory of Trauma, Burns and Combined Injury, Trauma Center, Research Institute of Surgery, Daping Hospital, Army Medical University, Chongqing, China
| | - Dali Zhang
- Department of Wound Repair and Rehabilitation Medicine, State Key Laboratory of Trauma, Burns and Combined Injury, Trauma Center, Research Institute of Surgery, Daping Hospital, Army Medical University, Chongqing, China
| | - Fengtao Luo
- Department of Wound Repair and Rehabilitation Medicine, State Key Laboratory of Trauma, Burns and Combined Injury, Trauma Center, Research Institute of Surgery, Daping Hospital, Army Medical University, Chongqing, China
| | - Hangang Chen
- Department of Wound Repair and Rehabilitation Medicine, State Key Laboratory of Trauma, Burns and Combined Injury, Trauma Center, Research Institute of Surgery, Daping Hospital, Army Medical University, Chongqing, China
| | - Xianding Sun
- Department of Wound Repair and Rehabilitation Medicine, State Key Laboratory of Trauma, Burns and Combined Injury, Trauma Center, Research Institute of Surgery, Daping Hospital, Army Medical University, Chongqing, China
| | - Jian Q Feng
- Department of Biomedical Sciences, Texas A&M University College of Dentistry, Dallas, TX, 75246, USA
| | - Huabing Qi
- Department of Wound Repair and Rehabilitation Medicine, State Key Laboratory of Trauma, Burns and Combined Injury, Trauma Center, Research Institute of Surgery, Daping Hospital, Army Medical University, Chongqing, China.
| | - Lin Chen
- Department of Wound Repair and Rehabilitation Medicine, State Key Laboratory of Trauma, Burns and Combined Injury, Trauma Center, Research Institute of Surgery, Daping Hospital, Army Medical University, Chongqing, China.
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3
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Ristic N, Ajdzanovic V, Manojlovic-Stojanoski M, Maliković J, Uscebrka G, Markovic Z, Milosevic V. Effects of Estradiol on Histological Parameters and Secretory Ability of Pituitary Mammotrophs in Ovariectomized Female Rats. CELL JOURNAL 2017; 19:461-468. [PMID: 28836408 PMCID: PMC5570411 DOI: 10.22074/cellj.2017.4334] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Accepted: 08/16/2016] [Indexed: 01/02/2023]
Abstract
Objective Estrogen replacement therapy remains current as a therapeutic approach to
treat menopausal symptoms and may significantly affect hormone-producing cells in the
female pituitaries. The aim of this study was to examine the histological parameters of
pituitary mammotrophs and prolactin secretion after chronic estradiol treatment in ovariectomized adult female rats, reflecting premature menopause. Materials and Methods In this experimental study, adult female Wistar rats were divided into non-ovariectomized (C),
ovariectomized (OVX) and estradiol-treated ovariectomized (OVX+E) groups. Estradiol dipropionate [0.625 mg/kg body mass per
day] was administered for four weeks, while the C and OVX groups received vehicle
alone. Mammotrophs were identified by the peroxidase-antiperoxidase (PAP) immunohistochemical procedure, while prolactin concentrations were measured by the
non-isotopic two-step assay (Delfia) method. Comparison of the differences between
groups was performed using one-way analysis of variance (ANOVA) and Tukay (honest significant difference) HSD test.
Results Ovariectomy caused significant (P<0.05) decreases in mammotroph optical
density (OD), volume density (VV) and number per mm2 by 29, 27 and 34%, respectively, in comparison with the C females. In the OVX+E group, significant (P<0.05)
increases in OD, cell volume, VVand number of mammotrophs per mm2 by 181, 15%,
5.8-fold and 5.2-fold, respectively, were observed when compared to OVX animals.
The serum prolactin concentration in OVX females was significantly (P<0.05) decreased by 14% in comparison to the C group, while in OVX+E females, prolactin
levels were significantly (P<0.05) increased by 53% compared to the OVX controls. Conclusion Estradiol supplementation in ovariectomized females is followed by
stimulatory histological and secretory changes of the mammotrophs. These results
could serve as indicators of possible prolactinome development upon estradiol application in premature menopausal subjects.
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Affiliation(s)
- Natasa Ristic
- Department of Cytology, Institute for Biological Research "Siniša Stanković", University of Belgrade, Belgrade, Serbia.
| | - Vladimir Ajdzanovic
- Department of Cytology, Institute for Biological Research "Siniša Stanković", University of Belgrade, Belgrade, Serbia.
| | - Milica Manojlovic-Stojanoski
- Department of Cytology, Institute for Biological Research "Siniša Stanković", University of Belgrade, Belgrade, Serbia
| | - Jovana Maliković
- Department of Cytology, Institute for Biological Research "Siniša Stanković", University of Belgrade, Belgrade, Serbia
| | - Gordana Uscebrka
- Department of Veterinary Medicine, Faculty of Agriculture, University of Novi Sad, Novi Sad, Serbia
| | | | - Verica Milosevic
- Department of Cytology, Institute for Biological Research "Siniša Stanković", University of Belgrade, Belgrade, Serbia
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Sabatino ME, Petiti JP, Sosa LDV, Pérez PA, Gutiérrez S, Leimgruber C, Latini A, Torres AI, De Paul AL. Evidence of cellular senescence during the development of estrogen-induced pituitary tumors. Endocr Relat Cancer 2015; 22:299-317. [PMID: 25792544 DOI: 10.1530/erc-14-0333] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 03/19/2015] [Indexed: 12/13/2022]
Abstract
Although pituitary adenomas represent 25% of intracranial tumors, they are usually benign, with the mechanisms by which these tumors usually avoid an invasive profile and metastatic growth development still remaining unclear. In this context, cellular senescence might constitute a plausible explanation for the benign nature of pituitary adenomas. In this study, we investigated the emergence of cellular senescence as a growth control mechanism during the progression of estrogen-induced pituitary tumors. The quantification of Ki67-immunopositive cells in the pituitaries of estrogenized male rats after 10, 20, 40, and 60 days revealed that the mitogenic potential rate was not sustained for the whole period analyzed and successively decreased after 10 days of estrogen exposure. In addition, the expression of cellular senescence features, such as the progressive rise in the enzymatic senescence-associated b-galactosidase (SA-b-gal) activity, IL6, IL1b, and TGFb expression, was observed throughout pituitary tumor development. Furthermore, tumoral pituitary cells also displayed nuclear pATM expression, indicating activated DNA damage signaling, with a significant increase in p21 expression also being detected. The associations among DNA damage signaling activation, SA-b-gal expression, and p21 may provide a reliable combination of senescence-associated markers for in vivo pituitary senescence detection. These results suggest a role for this cellular process in the regulation of pituitary cell growth. Thus, cellular senescence should be conceived as a contributing component to the benign nature of pituitary adenomas, thereby influencing the capability of the pituitary gland to avoid unregulated cell proliferation.
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Abstract
Pituitary adenomas are a heterogeneous group of tumors that may occur as part of a complex syndrome or as an isolated endocrinopathy and both forms can be familial or non-familial. Studies of syndromic and non-syndromic pituitary adenomas have yielded important insights about the molecular mechanisms underlying tumorigenesis. Thus, syndromic forms, including multiple endocrine neoplasia type 1 (MEN1), MEN4, Carney Complex and McCune Albright syndrome, have been shown to be due to mutations of the tumor-suppressor protein menin, a cyclin-dependent kinase inhibitor (p27Kip1), the protein kinase A regulatory subunit 1-α, and the G-protein α-stimulatory subunit (Gsα), respectively. Non-syndromic forms, which include familial isolated pituitary adenoma (FIPA) and sporadic tumors, have been shown to be due to abnormalities of: the aryl hydrocarbon receptor-interacting protein; Gsα; signal transducers; cell cycle regulators; transcriptional modulators and miRNAs. The roles of these molecular abnormalities and epigenetic mechanisms in pituitary tumorigenesis, and their therapeutic implications are reviewed.
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Affiliation(s)
- Christopher J Yates
- a 1 Academic Endocrine Unit, Radcliffe Department of Clinical Medicine, Oxford Centre for Diabetes, Endocrinology and Metabolism (OCDEM), University of Oxford, Churchill Hospital, Oxford, Oxfordshire, OX3 7LJ, UK
- b 2 Department of Diabetes and Endocrinology, Melbourne Health, The Royal Melbourne Hospital, Grattan Street, Parkville, Vic 3050, Australia
| | - Kate E Lines
- a 1 Academic Endocrine Unit, Radcliffe Department of Clinical Medicine, Oxford Centre for Diabetes, Endocrinology and Metabolism (OCDEM), University of Oxford, Churchill Hospital, Oxford, Oxfordshire, OX3 7LJ, UK
| | - Rajesh V Thakker
- a 1 Academic Endocrine Unit, Radcliffe Department of Clinical Medicine, Oxford Centre for Diabetes, Endocrinology and Metabolism (OCDEM), University of Oxford, Churchill Hospital, Oxford, Oxfordshire, OX3 7LJ, UK
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Sabatino ME, Sosa LDV, Petiti JP, Mukdsi JH, Mascanfroni ID, Pellizas CG, Gutiérrez S, Torres AI, De Paul AL. Functional Toll-like receptor 4 expressed in lactotrophs mediates LPS-induced proliferation in experimental pituitary hyperplasia. Exp Cell Res 2013; 319:3020-34. [DOI: 10.1016/j.yexcr.2013.08.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2013] [Revised: 07/26/2013] [Accepted: 08/06/2013] [Indexed: 11/29/2022]
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7
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Sosa LDV, Gutiérrez S, Petiti JP, Vaca AM, De Paul AL, Torres AI. Cooperative effect of E₂ and FGF2 on lactotroph proliferation triggered by signaling initiated at the plasma membrane. Am J Physiol Endocrinol Metab 2013; 305:E41-9. [PMID: 23651845 DOI: 10.1152/ajpendo.00027.2013] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In the present work, we investigated the effect of 17β-estradiol (E₂) and basic fibroblast growth factor 2 (FGF2) on the lactotroph cell-proliferative response and the related membrane-initiated signaling pathway. Anterior pituitary mixed-cell cultures of random, cycling 3-mo-old female rats were treated with 10 nM E₂, E₂ membrane-impermeable conjugated BSA (E₂-BSA), PPT (ERα agonist), and DPN (ERβ agonist) alone or combined with FGF2 (10 ng/ml) for 30 min or 4 h. Although our results showed that the uptake of BrdU into the nucleus of lactotrophs was not modified by E₂ or FGF2 alone, a significant increase in the lactotroph uptake of BrdU was observed after E₂/FGF2 coincubation, with this effect being mimicked by PPT/FGF2. These proliferative effects were blocked by ICI 182,780 or PD-98059. The involvement of membrane ER in the proliferative response of prolactin cells induced by the steroid and FGF2 coincubation was confirmed using E₂-BSA, and the association between ERα and FGF receptor was observed after E₂/FGF2 treatment by immunoprecipitation. A significant increase in the ERK1/2 expression was noted after E₂, E₂-BSA, PPT, and FGF2 alone, which was more noticeable after E₂-BSA/FGF2, E₂/FGF2, or PPT/FGF2 treatments. This study provides evidence that E₂ and FGF2 exert a cooperative effect on the lactotroph proliferation principally by signaling initiated at the plasma membrane triggering a genomic effect mediated by MEK/ERK1/2, a common signaling pathway, that finally regulates the lactotroph population, thus contributing to pituitary plasticity.
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Affiliation(s)
- Liliana del V Sosa
- Centro de Microscopía Electrónica, Instituto de Investigaciones en Ciencias de la Salud-Consejo Nacional de Investigaciones Científicas y Técnicas, Facultad de Ciencias Médicas, Universidad Nacional de Córdoba, Córdoba, Argentina
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Cornelius A, Cortet-Rudelli C, Assaker R, Kerdraon O, Gevaert MH, Prévot V, Lassalle P, Trouillas J, Delehedde M, Maurage CA. Endothelial expression of endocan is strongly associated with tumor progression in pituitary adenoma. Brain Pathol 2012; 22:757-64. [PMID: 22353248 DOI: 10.1111/j.1750-3639.2012.00578.x] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Although benign, pituitary adenomas frequently invade adjacent sinuses or recur after first surgery. To date, there is no histological marker predictive of recurrence. Angiogenic factors are candidate markers. Endocan is a proteoglycan secreted by endothelial cells, associated with an aggressive behavior in several tumor types. Endocan expression was investigated by immunohistochemistry and reverse transcription polymerase chain reaction (RT-PCR) in 18 normal post-mortem pituitaries and in 107 patients operated for a pituitary adenoma (with a follow-up of at least 8 years after surgery). In normal pituitaries, endocan was never observed in vessels but was detected in isolated endocrine cells. In adenoma tissue, we found a strong association between endocan immunoreactivity in endothelial cells and progression (P = 0.0009), as well as tumor size (P = 0.0012), raised mitotic count (P = 0.02) and p53 expression (P = 0.032). Morphometric analysis of the microvessels showed that the mean vessel area was significantly higher in the subgroup of tumors with an endothelial expression of endocan (P = 0.028), coherent with the neoangiogenesis process occurring in the pituitary. The immunolabeling of endocan in endothelial cells may therefore appear to be a relevant marker of aggressive behavior in pituitary tumors.
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9
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De Paul AL, Gutiérrez S, Sabatino ME, Mukdsi JH, Palmeri CM, Soaje M, Petiti JP, Torres AI. Epidermal growth factor induces a sexually dimorphic proliferative response of lactotroph cells through protein kinase C-ERK1/2-Pit-1 in vitro. Exp Physiol 2010; 96:226-39. [DOI: 10.1113/expphysiol.2010.054502] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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10
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Palmeri CM, Petiti JP, del Valle Sosa L, Gutiérrez S, De Paul AL, Mukdsi JH, Torres AI. Bromocriptine induces parapoptosis as the main type of cell death responsible for experimental pituitary tumor shrinkage. Toxicol Appl Pharmacol 2009; 240:55-65. [DOI: 10.1016/j.taap.2009.07.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2009] [Revised: 06/30/2009] [Accepted: 07/02/2009] [Indexed: 11/17/2022]
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Liao S, Bodmer J, Pietras D, Azhar M, Doetschman T, Schultz JEJ. Biological functions of the low and high molecular weight protein isoforms of fibroblast growth factor-2 in cardiovascular development and disease. Dev Dyn 2009; 238:249-64. [PMID: 18773489 DOI: 10.1002/dvdy.21677] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Fibroblast growth factor 2 (FGF2) consists of multiple protein isoforms (low molecular weight, LMW, and high molecular weight, HMW) produced by alternative translation from the Fgf2 gene. These protein isoforms are localized to different cellular compartments, indicating unique biological activity. FGF2 isoforms in the heart have distinct roles in many pathological circumstances in the heart including cardiac hypertrophy, ischemia-reperfusion injury, and atherosclerosis. These studies suggest distinct biological activities of FGF2 LMW and HMW isoforms both in vitro and in vivo. Yet, due to the limitations that only the recombinant FGF2 LMW isoform is readily available and that the FGF2 antibody is nonspecific with regards to its isoforms, much remains to be determined regarding the role(s) of the FGF2 LMW and HMW isoforms in cellular behavior and in cardiovascular development and pathophysiology. This review summarizes the activities of LMW and HMW isoforms of FGF2 in cardiovascular development and disease.
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Affiliation(s)
- Siyun Liao
- Department of Pharmacology and Cell Biophysics, University of Cincinnati, Cincinnati, Ohio, USA
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The G-rich promoter and G-rich coding sequence of basic fibroblast growth factor are the targets of thalidomide in glioma. Mol Cancer Ther 2008; 7:2405-14. [DOI: 10.1158/1535-7163.mct-07-2398] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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13
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Petiti JP, De Paul AL, Gutiérrez S, Palmeri CM, Mukdsi JH, Torres AI. Activation of PKC epsilon induces lactotroph proliferation through ERK1/2 in response to phorbol ester. Mol Cell Endocrinol 2008; 289:77-84. [PMID: 18534741 DOI: 10.1016/j.mce.2008.04.015] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/28/2007] [Revised: 04/09/2008] [Accepted: 04/18/2008] [Indexed: 10/22/2022]
Abstract
The aim of this investigation was to contribute to current knowledge about intracellular mechanisms that are involved in lactotroph cell proliferation, by evaluating the role of PKCalpha, PKCepsilon and extracellular-signal regulated kinase (ERK) 1/2 in response to phorbol 12-myristate13-acetate (PMA). In primary pituitary cultures, the activation of protein kinase C (PKC) by PMA for 15 min stimulated lactotroph proliferation; whereas a prolonged activation for 3-8h diminished this proliferative effect. The use of PMA for 15 min-activated PKCepsilon and ERK1/2, whereas incubation with PMA for 3 h induced PKCalpha activation and attenuated the PMA-triggered phosphorylation of ERK1/2. The following inhibitors: PKCs (bisindolylmaleimide I), PKCepsilon (epsilonV1 peptide) and ERK1/2 (PD98059) prevented the mitogenic activity induced by PMA for 15 min. Lactotroph cells stimulated with PMA for 15 min showed a translocation of PKCepsilon to membrane compartment and nucleus. These results thus establish that PKCepsilon plays an essential role in the lactotroph proliferation induced by PMA by triggering signals that involve ERK1/2 activation.
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Affiliation(s)
- Juan Pablo Petiti
- Centro de Microscopía Electrónica, Facultad de Ciencias Médicas, Universidad Nacional de Córdoba, Haya de la Torre esq. Enrique Barros, 5000 Córdoba, Argentina.
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14
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Cristina C, Díaz-Torga G, Góngora A, Guida MC, Perez-Millán MI, Baldi A, Becu-Villalobos D. Fibroblast growth factor-2 in hyperplastic pituitaries of D2R knockout female mice. Am J Physiol Endocrinol Metab 2007; 293:E1341-51. [PMID: 17848635 DOI: 10.1152/ajpendo.00260.2007] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Dopamine D2 receptor (D2R) knockout (KO) female mice develop chronic hyperprolactinemia and pituitary hyperplasia. Our objective was to study the expression of the mitogen fibroblast growth factor (FGF2) and its receptor, FGFR1, comparatively in pituitaries from KO and wild-type (WT) female mice. We also evaluated FGF2 subcellular localization and FGF2 effects on pituitary function. FGF2-induced prolactin release showed a similar response pattern in both genotypes, even though basal and FGF2-stimulated release was higher in KO. FGF2 stimulated pituitary cellular proliferation (MTS assay and [(3)H]thymidine incorporation), with no differences between genotypes. FGF2 concentration (measured by ELISA) in whole pituitaries or cultured cells was lower in KO (P < 0.00001 and 0.00014). Immunofluorescence histochemistry showed less FGF2 in pituitaries from KO females and revealed a distinct FGF2 localization pattern between genotypes, being predominantly nuclear in KO and cytosolic in WT pituitaries. Finally, FGF2 could not be detected in the conditioned media from pituitary cultures of both genotypes. FGFR1 levels (Western blot and immunohistochemistry) were higher in pituitaries of KO. Basal concentration of phosphorylated ERKs was lower in KO cells (P = 0.018). However, when stimulated with FGF2, a significantly higher increment of ERK phosphorylation was evidenced in KO cells (P < or = 0.02). We conclude that disruption of the D2R caused an overall decrease in pituitary FGF2 levels, with an increased distribution in the nucleus, and increased FGFR1 levels. These results are important in the search for reliable prognostic indicators for patients with pituitary dopamine-resistant prolactinomas, which will make tumor-specific therapy possible.
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MESH Headings
- Animals
- Blotting, Western
- Cell Growth Processes/physiology
- Enzyme-Linked Immunosorbent Assay
- Extracellular Signal-Regulated MAP Kinases/metabolism
- Female
- Fibroblast Growth Factor 2/metabolism
- Hyperplasia
- Immunohistochemistry
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Microscopy, Confocal
- Microscopy, Fluorescence
- Phosphorylation
- Pituitary Gland, Anterior/cytology
- Pituitary Gland, Anterior/metabolism
- Pituitary Gland, Anterior/pathology
- Prolactin/metabolism
- Prolactinoma/metabolism
- Receptor, Fibroblast Growth Factor, Type 1/metabolism
- Receptors, Dopamine D2/deficiency
- Receptors, Dopamine D2/metabolism
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Affiliation(s)
- Carolina Cristina
- Instituto de Biología y Medicina Experimental, CONICET, V Obligado 2490, 1428, Buenos Aires, Argentina
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15
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Spuch C, Diz-Chaves Y, Pérez-Tilve D, Alvarez-Crespo M, Mallo F. Prolactin-releasing Peptide (PrRP) increases prolactin responses to TRH in vitro and in vivo. Endocrine 2007; 31:119-24. [PMID: 17873321 DOI: 10.1007/s12020-007-0031-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/24/2007] [Revised: 05/17/2007] [Accepted: 05/17/2007] [Indexed: 11/25/2022]
Abstract
The Prolactin-releasing Peptide (PrRP) is a 31-aminoacid peptide produced and secreted from the hypothalamus, and postulated to promote the prolactin release from the pituitary. However, the action of PrRP remain controversial, since it was described to have potency comparable enough to TRH, although there are many evidences that PrRP is less potent than TRH. Here we have studied the effects of PrRP alone or in combination with TRH in the prolactin levels of rat pituitary primary cell cultures in vitro and also in vivo prolactin responses in randomly cycling and estrogens-treated female rats. PrRP itself increased prolactin levels in vitro and in vivo, although in a magnitude several times lower than TRH. In vivo PrRP promotes an atypical non-peaking progressive and maintained prolactin increase. On the other hand, PrRP markedly increased the prolactin responses to TRH in vitro (10-30 fold increase) and in vivo (up to three-fold increase). In addition, FGF-2 and EGF, two important growth factors present in the pituitary, reduced the PrRP-induced prolactin increase in vitro. Taken together our results suggest that PrRP released from the hypothalamus may be relevant to modulate the circulating prolactin levels in the rat.
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Affiliation(s)
- Carlos Spuch
- Department of Functional Biology and Health Sciences, Laboratory of Endocrinology, Faculty of Sciences, Campus of Vigo, University of Vigo, Vigo, 36310, Spain.
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