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Weigent DA. Lymphocyte GH-axis hormones in immunity. Cell Immunol 2013; 285:118-32. [PMID: 24177252 DOI: 10.1016/j.cellimm.2013.10.003] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Accepted: 10/10/2013] [Indexed: 10/26/2022]
Abstract
The production and utilization of common ligands and their receptors by cells of the immune and neuroendocrine systems constitutes a biochemical information circuit between and within the immune and neuroendocrine systems. The sharing of ligands and receptors allows the immune system to serve as the sixth sense notifying the nervous system of the presence of foreign entities. Within this framework, it is also clear that immune cell functions can be altered by neuroendocrine hormones and that cells of the immune system have the ability to produce neuroendocrine hormones. This review summarizes a part of this knowledge with particular emphasis on growth hormone (GH). The past two decades have uncovered a lot of detail about the actions of GH, acting through its receptor, at the molecular and cellular level and its influence on the immune system. The production and action of immune cell-derived GH is less well developed although its important role in immunity is also slowly emerging. Here we discuss the production of GH, GH-releasing hormone (GHRH) and insulin-like growth factor-1 (IGF-1) and their cognate receptors on cells of the immune system and their influence via endocrine/autocrine/paracrine and intracrine pathways on immune function. The intracellular mechanisms of action of immune cell-derived GH are still largely unexplored, and it is anticipated that further work in this particular area will establish an important role for this source of GH in normal physiology and in pathologic situations.
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Affiliation(s)
- Douglas A Weigent
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, 1918 University Blvd., MCLM894, Birmingham, AL 35294-0005, United States.
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Devesa P, Reimunde P, Gallego R, Devesa J, Arce VM. Growth hormone (GH) treatment may cooperate with locally-produced GH in increasing the proliferative response of hippocampal progenitors to kainate-induced injury. Brain Inj 2011; 25:503-10. [PMID: 21456999 DOI: 10.3109/02699052.2011.559611] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
PRIMARY OBJECTIVE This study was designed to investigate the effect of growth hormone treatment on the proliferation of endogenous neural progenitor cells in the dentate gyrus (DG) of the brain stimulated by kainic acid (KA)-induced neurotoxicity. RESEARCH DESIGN Neurotoxicity was induced by intraperitoneal injection of KA. GH treatment lasted 4 days, starting either immediately or after 10 days of administration of the neurotoxic insult. METHODS AND PROCEDURE Proliferating cells were immunodetected after labelling by in vivo administration of 5-bromodeoxyuridine (BrdU). GH expression was detected by in situ hybridization and immunofluorescence. MAIN OUTCOMES AND RESULTS KA administration stimulated the proliferation of hippocampal precursors and this effect was significantly enhanced by GH treatment. Hippocampal GH expression was also up-regulated in response to KA administration. CONCLUSIONS The findings support the possibility that the proliferative response observed in the hippocampus of rats treated with KA and GH is a consequence of cooperation between the exogenous and the locally-produced hormone and their synergism with other mitogenic factors generated in response to the neurotoxic damage. Therefore, GH treatment could be used to cooperate with other physiological or pathological stimuli in order to promote cell proliferation.
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Affiliation(s)
- Pablo Devesa
- Department of Physiology, School of Medicine, University of Santiago de Compostela, Spain
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Weigent DA. High molecular weight isoforms of growth hormone in cells of the immune system. Cell Immunol 2011; 271:44-52. [PMID: 21741628 DOI: 10.1016/j.cellimm.2011.06.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2011] [Revised: 05/06/2011] [Accepted: 06/01/2011] [Indexed: 01/05/2023]
Abstract
A substantial body of research exists to support the idea that cells of the immune system produce growth hormone (GH). However, the structure and mechanism of action of lymphocyte-derived GH continues to remain largely unknown. Here we present the results of Western analysis of whole cell extracts showing that different molecular weight isoforms of GH of approximately 100, 65, and 48 kDa can be detected in primary mouse cells of the immune system and in the mouse EL4 cell line. The identity of the 65 and 48 kDa isoforms of GH were confirmed by mass spectrometry. The various isoforms were detected in both enriched T and B spleen cell populations. The large molecular weight isoform appears to reside primarily in the cytoplasm, whereas the lower molecular weight 65 and 48 kDa isoforms were detected primarily in the nucleus. These results also suggest that GH isoforms are induced by oxidative stress. In EL4 cells overexpressing GH, the expression of luciferase controlled by a promoter containing the antioxidant response element is increased almost threefold above control. The data suggest that the induction of isoforms of the GH molecule in cells of the immune system may be an important mechanism of adaptation and/or protection of lymphoid cells under conditions of oxidative stress.
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Affiliation(s)
- Douglas A Weigent
- University of Alabama at Birmingham, Department of Physiology and Biophysics, Birmingham, AL 35294-0005, United States.
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Devesa J, Devesa P, Reimunde P. [Growth hormone revisited]. Med Clin (Barc) 2009; 135:665-70. [PMID: 20045134 DOI: 10.1016/j.medcli.2009.10.017] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2009] [Revised: 10/09/2009] [Accepted: 10/21/2009] [Indexed: 02/02/2023]
Abstract
Growth hormone (GH) is a pleiotropic hormone, expressed at pituitary and peripheral level, which plays a number of different roles far beyond of those classically described. Among these effects it is remarkable the neurotropic role of GH: the hormone increases the proliferation and survival of neural precursors in response to neurological injuries. At the cardiovascular level, GH improves the lipidic profile and decreases the factors of cardiac risk; the hormone recovers the endothelial function, improves the cardiac function and potentiates revascularisation in ischemic territories. Differently to that occurring with autocrine GH, exogenous GH administration does not seem to be related to oncogenesis. According to its effects, there are multiple potential clinical applications of GH: acute treatment of brain injury, due to its antiapoptotic effect; central or peripheral neural regeneration; acute treatment of perinatal anoxia, prevention cerebral palsy; revascularisation of ischemic areas; decrease of the time of bone consolidation after a bone fracture; and torpid ulcer healing.
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Affiliation(s)
- Jesús Devesa
- Departamento de Fisiología, Facultad de Medicina, Santiago de Compostela, España; Centro Médico Proyecto Foltra, Cacheiras, Teo, A Coruña, España.
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Japón MA, Urbano AG, Sáez C, Segura DI, Cerro AL, Diéguez C, Alvarez CV. Glial-derived neurotropic factor and RET gene expression in normal human anterior pituitary cell types and in pituitary tumors. J Clin Endocrinol Metab 2002; 87:1879-84. [PMID: 11932334 DOI: 10.1210/jcem.87.4.8383] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Glial-derived neurotropic factor (GDNF) signaling is mediated through a 2-component system consisting of the so-called GDNF receptor-alpha (GFRalpha1), which binds to GDNF. This complex activates the tyrosine kinase receptor RET. In this paper we demonstrate GDNF, GFRalpha1, and RET mRNA and protein expression in the human anterior pituitary gland. Double immunohistochemistry of anterior pituitary sections showed GDNF immunoreactivity in more than 95% of somatotrophs and to a lesser extent in corticotrophs (20%); it was almost absent in the remaining cell types. Also, although more than 95% of somatotrophs were stained for RET, no positive immunostaining could be detected in other cell types. Furthermore, we have looked for GDNF and RET in human pituitary adenomas of various hormonal phenotypes. Strong positive immunostaining was found for c-RET in all of the GH-secreting adenomas screened as well as in 50% of ACTH-producing adenomas. Positive immunostaining for GDNF was found in all of the GH-secreting adenomas and in 10% of the corticotropinomas. Lastly, we found strong positive immunostaining for GFRalpha1 in 90% of the somatotropinomas and 50% of the corticotropinomas as well as in 1 of 8 prolactinomas and 1 of 13 nonfunctioning adenomas. All of the remaining pituitary tumors screened were negative for RET, GDNF, and GFRalpha1. This study indicates that GDNF may well be acting in the regulation of somatotroph cell growth and/or cell function in the normal human anterior pituitary gland. The expression of RET in all of the somatotropinomas and in 50% of the ACTH-producing tumors implies that GDNF and RET could be involved in the pathogenesis of pituitary tumors.
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Affiliation(s)
- Miguel A Japón
- Department of Pathology, Hospital Universitario Virgen del Rocío, 41013 Sevilla, Spain
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Harvey S, Azumaya Y, Hull KL. Pituitary and extrapituitary growth hormone: Pit-1 dependence? Can J Physiol Pharmacol 2000. [DOI: 10.1139/y00-095] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Growth hormone (GH) is primarily produced in pituitary somatotrophs. The synthesis of this hormone is thought to be dependent upon a pituitary-specific transcription factor (Pit-1). However, many extrapituitary tissues are now known to express GH genes. The extrapituitary production of GH may therefore indicate an extrapituitary distribution of the Pit-1 gene. The extrapituitary production of GH may, alternatively, indicate that GH expression occurs independently of Pit-1 in extrapituitary tissues. These possibilities are considered in this brief review.Key words: growth hormone, pituitary, pituitary transcription factor 1.
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Garcia-Barros M, Devesa J, Arce VM. Proteolytic processing of human growth hormone (GH) by rat tissues in vitro: influence of sex and age. J Endocrinol Invest 2000; 23:748-54. [PMID: 11194709 DOI: 10.1007/bf03345065] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Although a wealth of evidence exists indicating that proteolytic cleavage can enhance the biological activity of the growth hormone (GH) molecule, the mechanisms responsible for the generation of GH fragments are not completely understood. In the present work we investigated the ability of different rat tissues to cleave 22 kDa GH, as well as the influence of sex and age, the two major physiological regulators of GH secretion on this process. Our results show that tissue homogenates obtained from rat liver, skeletal muscle or adipose tissue (three well-documented target organs for the hormone) are able to cleave 22K-GH, while the hormone is resistant to cleavage by rat brain homogenates. This process is rather selective for 22K-GH, since the 20 kDa GH variant exhibits stability to degradation by all tissue homogenates investigated. Moreover, only a minor fraction of 22 kDa GH is cleaved under our experimental conditions, suggesting that GH microheterogeneity within the 22 kDa range may also determine hormone susceptibility. Finally, we also found that 22K-GH processing shows important age-related changes (the greatest intensity observed in 4-day-old pups), while no gender-related differences exist in any of the tissues investigated.
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Affiliation(s)
- M Garcia-Barros
- Department of Physiology, Faculty of Medicine, University of Santiago de Compostela, Spain
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Costoya JA, Ríos R, García-Barros M, Gallego R, García-Caballero T, Señarís R, Arce VM, Devesa J. Role of growth hormone receptor in HL-60 cell survival. MOLECULAR CELL BIOLOGY RESEARCH COMMUNICATIONS : MCBRC 2000; 4:26-31. [PMID: 11152624 DOI: 10.1006/mcbr.2000.0252] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Although it is presently well established that locally produced growth hormone (GH) plays a major role in the regulation of survival mechanisms in hemopoietic cells, the responsible mechanisms are poorly understood, and the involvement of the GH receptor (GHR) has not even been demonstrated to date. In this work we investigated the presence of GHR in the human promyelocytic leukemia cell line HL-60, as well as the ability of GH treatment to stimulate both GHR and survival signaling pathways downstream GHR. Our results demonstrate that (1) both GHR mRNA and GHR immunoreactivity are present in HL-60 cells; (2) GH treatment results in an increase in the phosphorylation of the GHR-associated Jak2 and Stat3 proteins, indicating the ability of the hormone to induce receptor activation; and (3) activation of GHR increases the activity of Akt, a serine/threonine kinase that plays a prominent role in the regulation of cell survival. Taken together, these results demonstrate that GHR activation promotes survival of HL-60 cells, thus suggesting that GH plays a major role in the regulation of cell survival in the hemopoietic system, via an autocrine/paracrine mechanism.
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Affiliation(s)
- J A Costoya
- Departamento de Fisiología, Facultad de Medicina, Santiago de Compostela, 15705, Spain
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Castro JR, Costoya JA, Gallego R, Prieto A, Arce VM, Señarís R. Expression of growth hormone receptor in the human brain. Neurosci Lett 2000; 281:147-50. [PMID: 10704764 DOI: 10.1016/s0304-3940(00)00830-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
This study was designed to investigate the presence of growth hormone receptor (GHR) expression in the human brain tissue, both normal and tumoral, as well as in the human glioblastoma cell line U87MG. Reverse transcription-polymerase chain reaction revealed the presence of GHR mRNA in all brain samples investigated and in U87MG cells. GHR immunoreactivity was also detected in this cell line using both immunocytochemistry and western blotting. All together, our data demonstrate the existence of GHR expression within the central nervous system (CNS), thus supporting a possible role for GH in the CNS physiology.
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Affiliation(s)
- J R Castro
- Departamento de Fisioloxía, Facultad de Medicina, San Francisco 1, 15705 Santiago de, Compostela, Spain
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Costoya JA, Finidori J, Moutoussamy S, Seãris R, Devesa J, Arce VM. Activation of growth hormone receptor delivers an antiapoptotic signal: evidence for a role of Akt in this pathway. Endocrinology 1999; 140:5937-43. [PMID: 10579361 DOI: 10.1210/endo.140.12.7209] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
A signaling pathway was delineated by which GH promotes cell survival. Experiments were performed in human leukemic cells (HL-60) and Chinese hamster ovary (CHO) cells. In HL-60 cells, GH treatment reduced starvation-induced cell death. In contrast, when HL-60 cells were treated with an anti-GH antibody, cell survival was sharply reduced. In CHO cells stably expressing either the wild-type (wtGHR) or a truncated form (delta454GHR) of the GH receptor in which GH induces a sustained activation of the receptor-associated tyrosine kinase JAK2, we found that GH stimulation inhibited programmed cell death induced by withdrawal of survival factors. This effect was enhanced in cells expressing the truncated form. In contrast, GH did not affect cell survival in CHO cells transfected with either the empty vector or a mutated GHR unable to transduce the signal (4P/AGHR). We also showed that the inhibitory action of GH on apoptosis is probably mediated via stimulation of the serine-threonine kinase Akt, as 1) GH treatment induces a prompt phosphorylation of Akt; and 2) GH effects on cell survival are abolished by transfection of an Akt mutant that exhibits dominant negative function. Experiments with pharmacological inhibitors demonstrated that GH-induced Akt phosphorylation is dependent on phosphoinositide 3-kinase activation. In contrast, we found no changes in Bcl-2 levels secondary to GHR activation.
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Affiliation(s)
- J A Costoya
- Departamento de Fisioloxía, Facultade de Medicina, Universidade de Santiago de Compostela, Spain
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Kaulsay KK, Mertani HC, Törnell J, Morel G, Lee KO, Lobie PE. Autocrine stimulation of human mammary carcinoma cell proliferation by human growth hormone. Exp Cell Res 1999; 250:35-50. [PMID: 10388519 DOI: 10.1006/excr.1999.4492] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Here we have investigated the role of autocrine production of human growth hormone (hGH) in the proliferation of mammary carcinoma cells (MCF-7) in vitro. MCF-7 cells were stably transfected with an expression plasmid encoding the hGH gene, and these cells (designated MCF-hGH) synthesized hGH in the cell and secreted hGH to the medium. For control purposes, a MCF cell line was generated (MCF-MUT) in which the start codon of the hGH gene was disabled, and these cells transcribed the hGH gene without translation to hGH protein. The MCF-hGH cell number increased at a rate significantly greater than that of MCF-MUT under serum-free conditions. Autocrine hGH also synergized with 10% serum and insulin-like growth factor-1 but not 17-beta-estradiol to increase cell number. The increased proliferation of MCF-hGH cells in both serum-free and serum-containing media could be completely abrogated by the use of the nonreceptor dimerizing hGH antagonist, hGH-G120R. Increased mitogenesis as a consequence of autocrine production of hGH was prevented by inhibition of either the p38 MAPK or p42/44 MAPK pathways. MCF-hGH cells also possessed a higher level of STAT5 (but not STATs 1 and 3) mediated transcriptional activation in both serum-free and serum-containing conditions than MCF-MUT cells. Thus we conclude that hGH can act in an autocrine/paracrine manner in human mammary carcinoma cells to promote cell proliferation and transcriptional activation.
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Affiliation(s)
- K K Kaulsay
- National University Hospital, National University of Singapore, 10 Kent Ridge Crescent, Singapore, 119260, Republic of Singapore
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Costoya JA, García-Barros M, Gallego R, Señarís R, Arce VM, Devesa J. Correlation of Pit-1 gene expression and Pit-1 content with proliferation and differentiation in human myeloid leukemic cells. Exp Cell Res 1998; 245:132-6. [PMID: 9828108 DOI: 10.1006/excr.1998.4232] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The transcription factor pituitary-1 (Pit-1) is a homeodomain-containing protein that is expressed mainly in the pituitary, where it drives the expression of growth hormone, prolactin, and thyroid-stimulating hormone beta chain genes. In addition, Pit-1 is required for adequate pituitary cell growth and may be involved in the pathogenesis of pituitary adenomas. Pit-1 expression has been also reported in nonpituitary tissues, where it might be involved in the control of cell proliferation. In order to elucidate such a possibility, we have investigated the changes in both Pit-1 mRNA and Pit-1 immunoreactivity in HL-60 cells following the addition of several differentiating agents. Our results show that while high Pit-1 levels are found in exponentially growing HL-60 cells, a significant decrease occurs after induction of cells to differentiate along the macrophage lineage with 12-O-tetradecanoylphorbol-13-acetate (TPA). In contrast no changes were observed when cells were treated with interferon-alpha, which also induces differentiation of HL-60 cells that, at odds with TPA, is not accompanied with growth arrest. In all, these findings suggest that Pit-1 expression is specifically associated with proliferation in HL-60 cells, thus supporting the idea that one of the functions of nonpituitary Pit-1 may be the control of cell proliferation.
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Affiliation(s)
- J A Costoya
- Faculty of Medicine, University of Santiago de Compostela, Santiago de Compostela, 15705, Spain
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Abstract
A number of tissues, including the brain, pituitary, immune system, placenta, mammary gland, and testis, may be self-contained units of GH regulation, production, and action. The production of GH and GH-releasing factors outside the hypothalamo-pituitary axis complements, rather than replaces, the traditional endocrine interactions between GH-releasing factors, GH, and its target tissues.
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Affiliation(s)
- S Harvey
- Department of Physiology, University of Alberta, Edmonton, Canada.
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