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Muñoz‐Moreno L, Carmena MJ, Prieto JC, Schally AV, Bajo AM. Tumorigenic transformation of human prostatic epithelial cell line RWPE-1 by growth hormone-releasing hormone (GHRH). Prostate 2022; 82:933-941. [PMID: 35322894 PMCID: PMC9310601 DOI: 10.1002/pros.24339] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Revised: 11/30/2021] [Accepted: 12/17/2021] [Indexed: 11/15/2022]
Abstract
BACKGROUND Growth hormone-releasing hormone (GHRH) and its receptors have been implicated in the progression of various tumors. In this study, we analyzed the carcinogenetic potential of exposure to GHRH of a nontumor human prostate epithelial cell line (RWPE-1) as well as its transforming effect in a xenograft model. METHODS We performed cell viability, cell proliferation, adhesion and migration assays. In addition, metalloprotease (MMP)-2 activity by means gelatin zymography, GHRH-R subcellular location using confocal immunofluorescence microscopy and vascular endothelial growth factor (VEGF) levels by enzyme-linked immunoassay were assessed. Besides, we developed an in vivo model in order vivo model to determine the role of GHRH on tumorigenic transformation of RWPE-1 cells. RESULTS In cell cultures, we observed development of a migratory phenotype consistent with the gelatinolytic activity of MMP-2, expression of VEGF, as well as E-cadherin-mediated cell-cell adhesion and increased cell motility. Treatment with 0.1 µM GHRH for 24 h significantly increased cell viability and cell proliferation. Similar effects of GHRH were seen in RWPE-1 tumors developed by subcutaneous injection of GHRH-treated cells in athymic nude mice, 49 days after inoculation. CONCLUSIONS Thus, GHRH appears to act as a cytokine in the transformation of RWPE-1 cells by mechanisms that likely involve epithelial-mesenchymal transition, thus reinforcing the role of GHRH in tumorigenesis of prostate.
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Affiliation(s)
- Laura Muñoz‐Moreno
- Grupo de Investigación Cánceres de Origen Epitelial, Área de Bioquímica y Biología Molecular, Departamento de Biología de Sistemas, Facultad de Medicina y Ciencias de la SaludUniversidad de AlcaláAlcalá de HenaresMadridSpain
| | - M. José Carmena
- Grupo de Investigación Cánceres de Origen Epitelial, Área de Bioquímica y Biología Molecular, Departamento de Biología de Sistemas, Facultad de Medicina y Ciencias de la SaludUniversidad de AlcaláAlcalá de HenaresMadridSpain
| | - Juan C. Prieto
- Grupo de Investigación Cánceres de Origen Epitelial, Área de Bioquímica y Biología Molecular, Departamento de Biología de Sistemas, Facultad de Medicina y Ciencias de la SaludUniversidad de AlcaláAlcalá de HenaresMadridSpain
| | - Andrew V. Schally
- Endocrine, Polypeptide and Cancer InstituteVeterans Affairs Medical CenterMiamiFloridaUSA
- Division of Hematology/Oncology, Departments of Pathology and Medicine, Miller School of MedicineUniversity of MiamiMiamiFloridaUSA
- Department of Medicine, Sylvester Comprehensive Cancer Center, Miller School of MedicineUniversity of MiamiMiamiFloridaUSA
| | - Ana M. Bajo
- Grupo de Investigación Cánceres de Origen Epitelial, Área de Bioquímica y Biología Molecular, Departamento de Biología de Sistemas, Facultad de Medicina y Ciencias de la SaludUniversidad de AlcaláAlcalá de HenaresMadridSpain
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2
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Sanz Del Olmo N, Maroto-Diaz M, Quintana S, Gómez R, Holota M, Ionov M, Bryszewska M, Carmena MJ, Ortega P, Javier de la Mata F. Heterofunctional ruthenium(II) carbosilane dendrons, a new class of dendritic molecules to fight against prostate cancer. Eur J Med Chem 2020; 207:112695. [PMID: 32882608 DOI: 10.1016/j.ejmech.2020.112695] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 07/22/2020] [Accepted: 07/23/2020] [Indexed: 12/20/2022]
Abstract
A family of heterofunctional Schiff base carbosilane metallodendrons with [Ru(η5-C5H5)(PTA)Cl] (PTA = 1,3,5-triaza-7-phosphatricyclo-[3.3.1.1]decane) at the focal point and dimethylamino groups on the periphery are described. The new systems have proved their ability to interact with biological molecules such as Human Serum Albumin (HSA) without affecting its secondary structure and erythrocytes membranes, causing haemolysis in a dose and generation dependent way. The combination of two active functional groups in one single dendritic platform has shown a cooperative effect in the viability of HeLa and PC-3 cells, with the second generation derivative standing out as the most promising with the lowest IC50. Experiments focused on advanced prostate cancer have shown an antimetastasic activity for those metallodendrons, hindering the adhesion of cells in one of the main targets of metastasis, bones, and inhibiting cell migration. Finally, the second generation metallodendron with one single metal centre and four dimethylamino groups on the dendritic wedge, was selected for an ex vivo experiment in nude mice with advanced prostate cancer inhibiting the tumour growth in a 40% compared to control mice.
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Affiliation(s)
- Natalia Sanz Del Olmo
- Department of Organic and Inorganic Chemistry, Research Institute in Chemistry "Andrés M. Del Río" (IQAR), University of Alcalá, Madrid, Spain; Biomaterials and Nanomedicine (CIBER-BBN), Spain, Institute "Ramón y Cajal" for Health Research (IRYCIS), Spain
| | - Marta Maroto-Diaz
- Department of Organic and Inorganic Chemistry, Research Institute in Chemistry "Andrés M. Del Río" (IQAR), University of Alcalá, Madrid, Spain
| | - Sara Quintana
- Department of Organic and Inorganic Chemistry, Research Institute in Chemistry "Andrés M. Del Río" (IQAR), University of Alcalá, Madrid, Spain; Biomaterials and Nanomedicine (CIBER-BBN), Spain, Institute "Ramón y Cajal" for Health Research (IRYCIS), Spain
| | - Rafael Gómez
- Department of Organic and Inorganic Chemistry, Research Institute in Chemistry "Andrés M. Del Río" (IQAR), University of Alcalá, Madrid, Spain; Biomaterials and Nanomedicine (CIBER-BBN), Spain, Institute "Ramón y Cajal" for Health Research (IRYCIS), Spain
| | - Marcin Holota
- Department of General Biophysics, Faculty of Biology and Environmental Protection, University of Lodz, Pomorska 141/143, 90-236, Lodz, Poland
| | - Maksim Ionov
- Department of General Biophysics, Faculty of Biology and Environmental Protection, University of Lodz, Pomorska 141/143, 90-236, Lodz, Poland
| | - Maria Bryszewska
- Department of General Biophysics, Faculty of Biology and Environmental Protection, University of Lodz, Pomorska 141/143, 90-236, Lodz, Poland
| | - M José Carmena
- Department of Biology of Systems, Biochemistry and Molecular Biology Unit, University of Alcalá, Madrid, Spain
| | - Paula Ortega
- Department of Organic and Inorganic Chemistry, Research Institute in Chemistry "Andrés M. Del Río" (IQAR), University of Alcalá, Madrid, Spain; Biomaterials and Nanomedicine (CIBER-BBN), Spain, Institute "Ramón y Cajal" for Health Research (IRYCIS), Spain.
| | - F Javier de la Mata
- Department of Organic and Inorganic Chemistry, Research Institute in Chemistry "Andrés M. Del Río" (IQAR), University of Alcalá, Madrid, Spain; Biomaterials and Nanomedicine (CIBER-BBN), Spain, Institute "Ramón y Cajal" for Health Research (IRYCIS), Spain.
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3
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Maroto-Diaz M, Sanz del Olmo N, Muñoz-Moreno L, Bajo AM, Carmena MJ, Gómez R, García-Gallego S, de la Mata FJ. In vitro and in vivo evaluation of first-generation carbosilane arene Ru(II)-metallodendrimers in advanced prostate cancer. Eur Polym J 2019. [DOI: 10.1016/j.eurpolymj.2019.01.047] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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Muñoz-Moreno L, Schally AV, Prieto JC, Carmena MJ, Bajo AM. Growth hormone-releasing hormone receptor antagonists modify molecular machinery in the progression of prostate cancer. Prostate 2018; 78:915-926. [PMID: 29748961 DOI: 10.1002/pros.23648] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2018] [Accepted: 04/12/2018] [Indexed: 01/31/2023]
Abstract
BACKGROUND Therapeutic strategies should be designed to transform aggressive prostate cancer phenotypes to a chronic situation. To evaluate the effects of the new growth hormone-releasing hormone receptor (GHRH-R) antagonists: MIA-602, MIA-606, and MIA-690 on processes associated with cancer progression as cell proliferation, adhesion, migration, and angiogenesis. METHODS We used three human prostate cell lines (RWPE-1, LNCaP, and PC3). We analyzed several molecules such as E-cadherin, β-catenin, Bcl2, Bax, p53, MMP2, MMP9, PCNA, and VEGF and signaling mechanisms that are involved on effects exerted by GHRH-R antagonists. RESULTS GHRH-R antagonists decreased cell viability and provoked a reduction in proliferation in LNCaP and PC3 cells. Moreover, GHRH-R antagonists caused a time-dependent increase of cell adhesion in all three cell lines and retarded the wound closure with the highest value with MIA-690 in PC3 cells. GHRH-R antagonists also provoked a large number of cells in SubG0 phase revealing an increase in apoptotic cells in PC3 cell line. CONCLUSIONS Taken all together, GHRH-R antagonists of the MIAMI series appear to be inhibitors of tumor progression in prostate cancer and should be considered for use in future therapeutic strategies on this malignancy.
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Affiliation(s)
- Laura Muñoz-Moreno
- Department of Systems Biology, University of Alcalá, Alcalá de Henares, Madrid, Spain
| | - Andrew V Schally
- Veterans Affairs Medical Center, Miami, Florida
- Departments of Pathology and Medicine, Divisions of Hematology/Oncology, Sylvester Comprehensive Cancer Center, University of Miami, Miller School of Medicine, Miami, Florida
| | - Juan C Prieto
- Department of Systems Biology, University of Alcalá, Alcalá de Henares, Madrid, Spain
| | - M José Carmena
- Department of Systems Biology, University of Alcalá, Alcalá de Henares, Madrid, Spain
| | - Ana M Bajo
- Department of Systems Biology, University of Alcalá, Alcalá de Henares, Madrid, Spain
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5
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García-Fernández MO, Solano RM, Sánchez-Chapado M, Ruiz-Villaespesa A, Prieto JC, Carmena MJ. Low expression of Galpha protein subunits in human prostate cancer. J Urol 2001; 166:2512-7. [PMID: 11696820] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
PURPOSE Because of increasing interest in G protein regulation of cell growth, differentiation and oncogenesis, we studied the functionality and expression of different G protein subunits in human prostate adenocarcinoma. MATERIALS AND METHODS Surgical prostate specimens from control patients with bladder cancer and patients with prostate cancer were used. The functionality of alphas and alphai G protein subunits was evaluated by studying somatostatin or guanyl-5'-yl-imidotriphosphate regulation of forskolin stimulated adenylyl cyclase activity. The expression of alphas, alphai and beta subunits was studied by reverse transcriptase-polymerase chain reaction and immunoblot analysis. RESULTS Adenylyl cyclase sensitivity to somatostatin inhibition decreased in prostate cancer. Low guanyl-5'-yl-imidotriphosphate doses inhibited forskolin stimulated adenylyl cyclase, whereas the opposite was true at high concentrations, evidencing the functionality of alphai and alphas, respectively, in normal and cancer tissue samples. Reverse transcriptase-polymerase chain reaction revealed RNA encoding for alphas and alphai1,2,3 subclasses in normal and pathological conditions. However, immunoblot analysis showed that the level of beta subunits was maintained, whereas that of alphas and alphai subunits decreased 30% to 40% after neoplastic transformation. The levels of alphas and alphai1,2 subunits correlated inversely with serum prostate specific antigen in patients with prostate cancer. CONCLUSIONS The functionality and expression of G protein subunits are selectively modified in human prostate adenocarcinoma. Low alphas and alphai levels in prostate cancer suggest an important regulatory role of G proteins for cell proliferation and neoplastic transformation in the human prostate and they may have prognostic value.
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Affiliation(s)
- M O García-Fernández
- Departamento de Bioquímica y Biología Molecular, Universidad de Alcalá, Hospital Universitario Príncipe de Asturias, Alcalá de Henares, Spain
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Juarranz MG, Bolaños O, Gutiérrez-Cañas I, Lerner EA, Robberecht P, Carmena MJ, Prieto JC, Rodríguez-Henche N. Neuroendocrine differentiation of the LNCaP prostate cancer cell line maintains the expression and function of VIP and PACAP receptors. Cell Signal 2001; 13:887-94. [PMID: 11728828 DOI: 10.1016/s0898-6568(01)00199-1] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The molecular mechanisms involved in differentiation of prostate cancer cells to a neuroendocrine (NE) cell phenotype are not well understood. Here we used the androgen-dependent human prostate cancer cell line LNCaP to perform a systematic and broad analysis of the expression, pharmacology, and functionality of vasoactive intestinal peptide (VIP)/pituitary adenylate cyclase-activating peptide (PACAP) receptors. Reverse transcription polymerase chain reaction experiments, together with pharmacological approaches with a set of specific agonists and antagonists, demonstrated the presence of the three VIP/PACAP receptor subtypes (PAC1, VPAC1, and VPAC2 with a major role for VPAC1, acting through adenylate cyclase (AC) stimulation. An essentially similar pattern was observed by NE differentiated cells (4 days after serum deprivation) in spite of the important morphological changes observed. However, the expression of the prostate-specific antigen (PSA) decreased in NE cells (and increased again by dihydrotestosterone, DHT, treatment). The present demonstration of the induction of NE transdifferentiation in LNCaP cells by increasing concentrations of VIP adds value to previous observations on the role of cAMP in this process, an interesting topic in the comprehension of the molecular changes that are involved in the progression of prostate cancer to androgen independence.
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MESH Headings
- Adenylyl Cyclases/metabolism
- Binding, Competitive
- Cell Differentiation
- Culture Media, Serum-Free
- Cyclic AMP/biosynthesis
- Dose-Response Relationship, Drug
- Humans
- Male
- Neurites/ultrastructure
- Neurons/cytology
- Neurons/metabolism
- Neuropeptides/pharmacology
- Neurosecretory Systems/cytology
- Neurosecretory Systems/metabolism
- Pituitary Adenylate Cyclase-Activating Polypeptide
- Prostatic Neoplasms/genetics
- Prostatic Neoplasms/metabolism
- Prostatic Neoplasms/pathology
- RNA, Neoplasm/biosynthesis
- Receptors, Pituitary Adenylate Cyclase-Activating Polypeptide
- Receptors, Pituitary Adenylate Cyclase-Activating Polypeptide, Type I
- Receptors, Pituitary Hormone/genetics
- Receptors, Pituitary Hormone/metabolism
- Receptors, Pituitary Hormone/physiology
- Receptors, Vasoactive Intestinal Peptide/genetics
- Receptors, Vasoactive Intestinal Peptide/metabolism
- Receptors, Vasoactive Intestinal Peptide/physiology
- Receptors, Vasoactive Intestinal Peptide, Type II
- Receptors, Vasoactive Intestinal Polypeptide, Type I
- Transcription, Genetic
- Tumor Cells, Cultured
- Vasoactive Intestinal Peptide/pharmacology
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Affiliation(s)
- M G Juarranz
- Department of Biochemistry and Molecular Biology, Universidad de Alcalá, 28871, Alcalá de Henares, Spain
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7
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Salvador A, García-Paramio MP, Sánchez-Chapado M, Carmena MJ, Prieto JC. Effects of the luteinising hormone-releasing hormone (LH-RH) agonist leuprolide on adenylyl cyclase regulation through G-protein coupled receptors in rat ventral prostate. Eur J Cancer 2001; 37:641-8. [PMID: 11290440 DOI: 10.1016/s0959-8049(00)00443-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Luteinising hormone-releasing hormone (LH-RH) agonists are widely used for the therapy of advanced prostate cancer through the suppression of testosterone secretion. Furthermore, recent studies indicate the existence of prostate LH-RH receptors coupled to signalling pathways resulting in direct antiproliferative effects. In order to shed light on the mechanisms through which these compounds inhibit prostate cell growth, we investigated the effects of leuprolide (a LH-RH agonist) treatment of rats compared with the effects of surgical castration on the behaviour of G-protein coupled receptors acting through adenylyl cyclase in the ventral prostate. Important decreases of both plasma testosterone levels and ventral prostate weight were observed 5 weeks after subcutaneous (s.c.) injection of a leuprolide-depot preparation (1.5 mg/kg body weight (b.w.)) or 5 days after bilateral gonadectomy. However, leuprolide treatment increased the number of vasoactive intestinal peptide (VIP) receptors and the ability of this neuropeptide to stimulate adenylyl cyclase activity in prostate membranes, whereas surgical castration decreased both parameters. Moreover, leuprolide resulted in significant increases of prostate alpha(s) and alpha(i1-3) (but not alpha(i1) and beta) G-protein levels, while the four G-protein subunits were overexpressed after gonadectomy. The estimation of alpha(s) and alpha(i) activity by experiments with Gpp[NH]p and forskolin indicated a potentiation of the two arms of adenylyl cyclase regulation in leuprolide-treated rats. Present observations suggest that leuprolide treatment leads to an antimitogenic response by acting mainly through the activation of Gi proteins negatively coupled to adenylyl cyclase.
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Affiliation(s)
- A Salvador
- Department of Biochemistry and Molecular Biology, University of Alcalá, E-28871 de Henares, Alcalá, Spain
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8
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Carmena MJ, Montalvo L, Solano RM, Clemente C, Román ID, Sánchez-Chapado M, Prieto JC. Effect of flutamide androgen-receptor blockade on rat prostatic VIP receptor/effector system. Ann N Y Acad Sci 2001; 921:377-80. [PMID: 11193859 DOI: 10.1111/j.1749-6632.2000.tb06999.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- M J Carmena
- Department of Biochemistry and Molecular Biology, Alcalá University, E-28871 Alcalá de Henares, Spain
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9
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Solano RM, García-Fernández MO, Clemente C, Querol M, Bellamy F, Sanchez-Chapado M, Prieto JC, Carmena MJ. Effects of Pygeum africanum extract (Tadenan) on vasoactive intestinal peptide receptors, G proteins, and adenylyl cyclase in rat ventral prostate. Prostate 2000; 45:245-52. [PMID: 11074527 DOI: 10.1002/1097-0045(20001101)45:3<245::aid-pros7>3.0.co;2-t] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
BACKGROUND Tadenan (a Pygeum africanum extract) is a drug used in the treatment of benign prostatic hyperplasia. Its effects on prostate fibroblast proliferation and bladder function after partial outlet obstruction have been demonstrated in various pharmacological studies. However, its effects at the molecular level are poorly documented. METHODS Tadenan was dissolved in peanut oil. Rats were orally given two daily doses of the drug (1 or 10 mg/kg b.w.) for 4 days. Vasoactive intestinal peptide (VIP) binding, adenylyl cyclase stimulation, and expression of G-protein subunits were studied in rat prostatic membranes by established procedures. RESULTS Tadenan treatment of castrated/testosterone-replaced rats was performed in order to interfere with prostatic cell proliferation. This experimental approach resulted in increases of: 1) VIP effect on adenylyl cyclase stimulation through alpha(s) G-subunit; 2) alpha(i) activation by low Gpp[NH]p doses (in the presence of forskolin); and 3) alpha(s), alpha(i1/2), and alpha(i3/0) levels. However, there were no modifications in membranes from quiescent, nonproliferating prostates (untreated rats). CONCLUSIONS The observed regulatory role of Tadenan on various prostatic components of the adenylyl cyclase system, together with previous findings on protein kinase C-mediated signal transduction, open a complex array of possibilities of direct actions of this phytotherapeutic agent in the prostate.
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Affiliation(s)
- R M Solano
- Unidad de Neuroendocrinología Molecular, Departamento de Bioquímica y Biología Molecular, Universidad de Alcalá, Alcalá de Henares, Spain
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10
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Montalvo L, Carmena MJ, Solano RM, Clemente C, Román ID, Sánchez-Chapado M, Prieto JC. Effect of flutamide-induced androgen-receptor blockade on adenylate cyclase activation through G-protein coupled receptors in rat prostate. Cell Signal 2000; 12:311-6. [PMID: 10822172 DOI: 10.1016/s0898-6568(00)00072-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The effect of the antiandrogen flutamide on the prostatic vasoactive intestinal peptide (VIP) receptor/effector system was studied in rats. Rats were s.c. injected with a daily dose of flutamide (15 mg/kg B.W.) or vehicle for 14 days. Drug treatment resulted in histological evidence of gland involution and increased plasma membrane fluidity as estimated by fluorescence spectroscopy. The number of VIP receptors and the stimulatory effect of VIP on adenylate cyclase activity in prostatic membranes decreased in flutamide-treated rats. However, the pattern of forskolin stimulation of the enzyme activity was not modified by this drug. Androgen-receptor blockade by flutamide also decreased the prostatic levels of alpha(s,) alpha(i1/2), and alpha(i3/0) G-protein subunits, as estimated by an immunological procedure. Whereas apoptotic DNA fragmentation was evidenced in prostate from 3-day castrated animals, a heterogeneous electrophoretic pattern was observed after flutamide treatment. Thus, androgen-receptor blockade by flutamide results in an important impairment of the components of the VIP receptor/effector system in rat prostate as well as in a modification of their coupling extent, which is presumably due to differences observed in plasma membrane fluidity. These results represent a crosstalk in the prostate between two mechanisms of signal transduction involved in cell proliferation.
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Affiliation(s)
- L Montalvo
- Department of Biochemistry and Molecular Biology, University of Alcalá, E-28871, Alcalá de Henares, Spain
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11
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Solano RM, Carmena MJ, Busto R, Sánchez-Chapado M, Guijarro LG, Prieto JC. Identification and functional properties of the pituitary adenylate cyclase activating peptide (PAC1) receptor in human benign hyperplastic prostate. Cell Signal 1999; 11:813-9. [PMID: 10617284 DOI: 10.1016/s0898-6568(99)00052-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Pituitary adenylate cyclase activating peptide (PACAP) is a novel neuropeptide with regulatory and trophic functions that is related to vasoactive intestinal peptide (VIP). Here we investigate the expression of specific PACAP receptors (PAC1) and common VIP/PACAP receptors (VPAC1 and VPAC2) in the human hyperplastic prostate by immunological methods. The PAC1 receptor corresponded to a 60-KDa protein whereas the already known VPAC1 and VPAC2 receptors possessed molecular masses of 58 and 68 KDa, respectively. The heterogeneity of VIP/PACAP receptors in this tissue was confirmed by radioligand binding studies using [125I]PACAP-27 by means of stoichiometric and pharmacological experiments. At least two classes of PACAP binding sites showing different affinities could be resolved, with Kd values of 0.81 and 51.4 nM, respectively. The order of potency in displacing [125I]PACAP-27 binding was PACAP-27 approximately equal to PACAP-38 > VIP. PACAP-27 and VIP stimulated similarly adenylate cyclase activity, presumably through common VIP/PACAP receptors. The PAC1 receptor was not coupled to activation of either adenylate cyclase, nitric oxide synthase, or phospholipase C. It appears to be a novel subtype of PAC1 receptor because PACAP-27 (but not PACAP-38 or VIP) led to increased phosphoinositide synthesis, an interesting feature because phosphoinositides are involved via receptor mechanisms in the regulation of cell proliferation.
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MESH Headings
- Aged
- Aged, 80 and over
- Blotting, Western
- Humans
- Iodine Radioisotopes
- Male
- Neuropeptides/metabolism
- Pituitary Adenylate Cyclase-Activating Polypeptide
- Prostate/metabolism
- Prostate/pathology
- Prostatic Hyperplasia/metabolism
- Prostatic Hyperplasia/pathology
- Radioligand Assay
- Receptors, Pituitary Adenylate Cyclase-Activating Polypeptide
- Receptors, Pituitary Adenylate Cyclase-Activating Polypeptide, Type I
- Receptors, Pituitary Hormone/metabolism
- Receptors, Pituitary Hormone/physiology
- Receptors, Vasoactive Intestinal Peptide/analysis
- Receptors, Vasoactive Intestinal Peptide, Type II
- Receptors, Vasoactive Intestinal Polypeptide, Type I
- Signal Transduction
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Affiliation(s)
- R M Solano
- Departamento de Bioquímica y Biología Molecular, Universidad de Alcalá, Alcalá de Henares, Spain
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12
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Carmena MJ, Camacho A, Solano RM, Montalvo L, Garcia-López E, Arias A, Prieto JC. 5-hydroxytryptamine1A receptor-mediated effects on adenylate cyclase and nitric oxide synthase activities in rat ventral prostate. Cell Signal 1998; 10:583-7. [PMID: 9794257 DOI: 10.1016/s0898-6568(97)00196-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The rat ventral prostate possesses specific 5-hydroxytryptamine (5-HT1A) receptors coupled to adenylate cyclase. In vivo treatment of rats or in vitro preincubation of minced prostatic tissue with the 5-HT1A receptor agonist 8-hydroxy-2-(di-N-propylamino)-tetralin (8-OH-DPAT) in different experimental conditions shows the possibility of desensitisation mechanisms with switching from inhibitory to stimulatory pattern on adenylate cyclase activity. As in the majority of systems, we observed the inhibition of forskolin-stimulated adenylate cyclase activity as a functional correlate of 5-HT1A receptor activation. A similar feature occurred when the direct stimulation of the enzyme by the diterpene was replaced by a receptor-mediated activation with the neuropeptide vasoactive intestinal peptide. Furthermore, 8-OH-DPAT stimulated nitric oxide synthase (NOS) activity in a dose-dependent manner. Thus, serotonin appears to be able to act in the rat prostate gland through specific 5-HT1A receptors coupled to a complex system of signal transduction involving an inhibitory response of adenylate cyclase that can become stimulatory, as well as an enhancement of NOS activity.
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Affiliation(s)
- M J Carmena
- Departamento de Bioquímica y Biología Molecular, Universidad de Alcalá, Alcalá de Henares, Spain.
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Abstract
BACKGROUND The consequences of experimental diabetes on membrane lipids, beta-adrenergic stimulation of adenylate cyclase activity, and G-protein levels in the prostate gland are not defined. METHODS Prostatic membranes from control and streptozotocin (STZ)-diabetic rats were used to study adenylate cyclase stimulation as well as for immunodetection of stimulatory (alpha s) and inhibitory (alpha i) G-protein subunits. Changes in membrane lipid composition were estimated by [1-14C] acetate incorporation into lipid subclasses. RESULTS The efficacy of isoproterenol on stimulation of adenylate cyclase activity and the levels of alpha s, alpha i1/2, and alpha i3/0 G-protein subunits were drastically reduced in prostatic membranes from STZ-diabetic rats. Insulin treatment of diabetic rats tended to normalize G-protein levels, but it was ineffective on the poor adenylate cyclase response to isoproterenol or forskolin. However, it prevented enzyme desensitization to vasoactive intestinal peptide. The pattern of [1-14C] acetate incorporation into lipid subclasses did not vary with diabetes or insulin treatment. CONCLUSIONS STZ-induced diabetes results in desensitization for the beta-adrenergic response of adenylate cyclase, as supported by previous data on the low density of beta-adrenergic receptors and the present results on the general decrease of Gs and Gi proteins levels and even of the enzyme itself in the diabetic rat prostate.
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Affiliation(s)
- M J Carmena
- Departamento de Bioquimica y Biología Molecular, Universidad de Alcalá, Spain
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14
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Juarranz MG, Carrero I, Busto R, Carmena MJ, Prieto JC, Guijarro LG. Ontogenic development of the adenylyl cyclase enzyme and the alpha s, alpha i1 and alpha i2 G-protein regulatory subunits from rat prostate. Cell Signal 1997; 9:451-6. [PMID: 9376227 DOI: 10.1016/s0898-6568(97)00037-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The expression of alpha s, alpha i1 and alpha i2 G-protein subunits measured by immunoblot increased in the rat prostate during sexual maturation, supporting their involvement in proliferation/differentiation. Northern blotting gave transcripts of 1.8 and 4 kb for alpha s, 1.4 and 4.5 kb (mainly) for alpha i1, and 2.4 kb for alpha i2 with levels suggesting a differential regulation (at transcription or post-transcription for alpha s, transcription for alpha i1, and translation for alpha i2). The stimulatory effects of forskolin, vasoactive intestinal peptide (VIP) and isoproterenol on adenylyl cyclase activity increased between 0.5-3 mo, remained constant up to 12 mo and decreased thereafter, conceivably following the expression of VIP and beta-adrenergic receptors. However, G-protein activation of adenylyl cyclase (by GTP and Gpp[NH]p) was maximal at 0.5 mo and then decreased as it occurred with toxin-catalyzed ADP-ribose incorporation to alpha subunits suggesting that other factors are also involved in the regulation of G-protein activity during rat prostatic development.
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Affiliation(s)
- M G Juarranz
- Departamento de Bioquímica y Biología Molecular, Universidad de Alcalá, Alcalá de Henares, Spain
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15
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Guijarro LG, Juarranz MG, Marinero MJ, Pajuelo L, Carmena MJ, Prieto JC. Modulation of cyclic AMP and inositol phosphate production in rat prostatic cultures by VIP/PACAP, ATP, and carbachol: role in prostatic proliferation. Ann N Y Acad Sci 1996; 805:723-8. [PMID: 8993468 DOI: 10.1111/j.1749-6632.1996.tb17548.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- L G Guijarro
- Department of Biochemistry and Molecular Biology, University of Alcalá, Alcalá de Henares, Madrid, Spain.
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16
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Affiliation(s)
- M J Carmena
- Department of Biochemistry and Molecular Biology, University of Alcalá, Alcalá de Henares, Spain.
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17
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Solano RM, Carmena MJ, Carrero I, Cavallaro S, Roman F, Hueso C, Travali S, Lopez-Fraile N, Guijarro LG, Prieto JC. Characterization of vasoactive intestinal peptide/pituitary adenylate cyclase-activating peptide receptors in human benign hyperplastic prostate. Endocrinology 1996; 137:2815-22. [PMID: 8770902 DOI: 10.1210/endo.137.7.8770902] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Vasoactive intestinal peptide (VIP) is an important member of the group of neuropeptides that appears to be involved in the regulation of prostatic growth and function. Here we studied VIP receptors in membranes from human benign hyperplastic prostate. Accordingly to observations in rat prostatic membranes, [125I]VIP binding to human prostatic membranes suggested two classes of binding sites with high Kd = 0.22 nM) and low (Kd = 37.7 nM) affinities. VIP bound in human and rat membrane preparations to a common VIP/pituitary adenylate cyclase-activating peptide (PACAP) receptor, as VIP, PACAP-27, and PACAP-38 were equipotent for competition of [125I]VIP binding. A PACAP-preferring receptor appears to be expressed in human prostate, since [125I]PACAP binding was displaced with more potency by PACAP than by VIP, and a messenger RNA corresponding to type I PACAP receptor was found. Cross-linking experiments suggested a VIP receptor of about 71 kDa in human and 52 kDa in rat prostates. The binding of [125I]VIP to membranes and the labeling of the bands observed after electrophoresis were competitively inhibited by GTP, suggesting the coupling of VIP receptors to a G protein. Moreover, after solubilization and cross-linking, we observed a 120-kDa band that corresponded to the VIP receptor-alpha s association. VIP stimulated adenylyl cyclase activity in a dose-dependent manner, but the potency and/or the efficacy of VIP were lower in all human preparations studied than in rat prostatic membranes. In conclusion, this study clearly demonstrates the expression of VIP/PACAP common receptors associated with alpha s protein in human prostate and suggests that these neuropeptides could play an important and complex role in the physiology and pathophysiology of this human gland.
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MESH Headings
- Adenylyl Cyclases/metabolism
- Aged
- Aged, 80 and over
- Animals
- Base Sequence
- Binding, Competitive
- Cell Membrane/metabolism
- DNA Primers
- GTP-Binding Proteins/metabolism
- Humans
- Kinetics
- Male
- Molecular Sequence Data
- Neuropeptides/metabolism
- Neuropeptides/pharmacology
- Neurotransmitter Agents/metabolism
- Neurotransmitter Agents/pharmacology
- Pituitary Adenylate Cyclase-Activating Polypeptide
- Polymerase Chain Reaction
- Prostate/metabolism
- Prostatectomy
- Prostatic Hyperplasia/metabolism
- Prostatic Hyperplasia/surgery
- RNA, Messenger/biosynthesis
- Radioligand Assay
- Rats
- Receptors, Pituitary Adenylate Cyclase-Activating Polypeptide
- Receptors, Pituitary Adenylate Cyclase-Activating Polypeptide, Type I
- Receptors, Pituitary Hormone/biosynthesis
- Receptors, Pituitary Hormone/metabolism
- Receptors, Vasoactive Intestinal Peptide/biosynthesis
- Receptors, Vasoactive Intestinal Peptide/metabolism
- Transcription, Genetic
- Vasoactive Intestinal Peptide/metabolism
- Vasoactive Intestinal Peptide/pharmacology
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Affiliation(s)
- R M Solano
- Department of Biochemistry and Molecular Biology, University of Alcalá, Alcalá de Henares, Spain
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18
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Garcia-Paramio PL, Carmena MJ, Guijarro LG, Prieto JC. Protein kinase C isozymes in prostatic epithelial cells from normal, diabetic and insulin-treated diabetic rats. Gen Pharmacol 1995; 26:1673-8. [PMID: 8745155 DOI: 10.1016/0306-3623(95)00035-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
1. Immunoblot experiments in rat prostatic epithelium using a non-selective antibody against protein kinase C (PKC) allowed to detect three PKC subspecies of 87.5, 55.5 and 34.6 kDa that showed higher, similar and lower immunoreactivity in the membrane than in the cytosolic compartment, respectively. 2. Specific monoclonal antisera revealed that the PKC-gamma isozyme is not expressed in the rat prostatic epithelium, whereas the PKC-beta isozyme was noted only in the cytosolic fraction showing an apparent molecular weight of 75.5 kDa. 3. Induction of diabetes by streptozotocin led to modifications in the expression of PKC isozymes so that the immunoreactivities of the 87.5- and 55.5-kDa PKC forms decreased in both cytosolic and membrane subcellular fractions to different extents. 4. The most important decrease was that of the 55.5-kDa PKC form in cytosol that returned to control values by insulin therapy, whereas PKC-beta suffered also some decrease in diabetes and increased again with insulin treatment.
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Affiliation(s)
- P L Garcia-Paramio
- Unidad de Neuroendocrinologia Molecular, Departamento de Bioquimica y Biologia Molecular, Universidad de Alcala, Spain
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19
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Abstract
In the context of the crosstalk between transmembrane signalling pathways, we studied the loci within the stimulatory receptor/Gs protein/adenylyl cyclase system at which protein kinase C (PKC) exerts regulatory effects in rat prostatic epithelial cells. The treatment of cells with the PKC activator phorbol 12-myristate 13-acetate (PMA) resulted in an impairment of the stimulation of adenylyl cyclase activity in terms of both potency, as seen with both vasoactive intestinal peptide (VIP) and pituitary adenylyl cyclase-activating peptide (PACAP-27), and efficacy, as seen with the beta-adrenergic agonist isoproterenol. This inhibitory effect of PMA could be prevented by cell incubation with pertussis toxin but not with cholera toxin, pointing to a Gi- but not Gs-dependent mechanism. This hypothesis was reinforced by ADP-ribosylation experiments that showed a low extent of alpha i with pertussis toxin but no change of alpha s with cholera toxin, as well as by the observation of the loss of the ability of low Gpp[NH]p doses to inhibit forskolin-stimulated adenylyl cyclase activity (a measure of Gi function) after cell treatment with PMA. However, the phorbol ester did not modify the adenylyl cyclase catalytic subunit, as shown by experiments on direct stimulation of the enzyme by forskolin. Whatever the exact mechanisms, the results support a crosstalk between the PKC and the adenylyl cyclase systems in rat prostatic epithelial cells in terms of an impairment of adenylyl cyclase stimulation, due presumably to phosphorylation of both membrane receptors (coupled to Gs) and Gi protein, but not of Gs protein or the adenylyl cyclase itself.
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Affiliation(s)
- M J Carmena
- Departamento de Bioquímica y Biología Molecular, Universidad de Alcalá, Spain
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20
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Abstract
Neuropeptide Y (NPY), a peptide present in the prostate gland, was found to inhibit vasoactive intestinal peptide (VIP)-stimulated cyclic AMP accumulation in isolated rat prostatic epithelial cells as well as VIP-stimulated adenylyl cyclase activity in rat prostatic membranes. The inhibitory effect of NPY was selective for the VIP receptor/effector system since it was also observed when using pituitary adenylyl cyclase activating peptide (PACAP-27) which presumably recognizes VIP receptors in this gland, but not when using unrelated substances such as isoproterenol or forskolin. NPY did not modify either the general lipid membrane microviscosity or the VIP-receptor binding. The inhibitory effect of VIP was blocked by pretreatment of the prostatic membranes with pertussis toxin. These results suggest the presence of NPY receptors in rat ventral prostate coupled in an inhibitory manner to adenylyl cyclase through a guanine nucleotide regulatory Gi protein.
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Affiliation(s)
- R M Solano
- Departamento de Bioquimica y Biologia Molecular, Universidad de Alcala, Alcala de Henares, Spain
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21
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Juarranz MG, Guijarro LG, Bajo AM, Carmena MJ, Prieto JC. Ontogeny of vasoactive intestinal peptide receptors in rat ventral prostate. Gen Pharmacol 1994; 25:509-14. [PMID: 7926599 DOI: 10.1016/0306-3623(94)90207-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
1. The stimulatory effect of VIP on rat prostatic adenylyl cyclase changes during postnatal development. It peaks at 2 months (peripubertal period), remains in a plateau between 3 and 12 months (adult period), and decreases at 24 months (old period). 2. The stimulation of rat prostatic adenylyl cyclase by the beta-adrenergic agonist isoproterenol follows a pattern rather similar to that of VIP. 3. The values of VIP binding capacity correlate well with those observed for adenylyl cyclase between 1 and 12 months, whereas there appears to exist a great number of uncoupled VIP receptors at 0.5 and 24 months. 4. The apparent molecular mass (51 kDa) of the rat prostatic VIP-receptor complex remains unaltered during ontogenic development.
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Affiliation(s)
- M G Juarranz
- Departamento de Bioquímica y Biología Molecular, Universidad de Alcalá, Alcalá de Henares, Spain
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22
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Abstract
The properties of protein kinase C (PKC) activity have been studied in cytosolic and membrane fractions from rat and human prostate. Ion exchange chromatography indicated the existence of different PKC isoforms, PKC from rat ventral prostate behaved as a classical Ca(2+)- and phospholipid-dependent enzyme and was activated by 1,2-diacylglycerol as well as by high concentrations of arachidonic acid. PKC activity in the cytosolic fraction was higher and presented different cofactor requirements than that in the membrane fraction. PKC from human benign hyperplastic prostate was also phospholipid dependent, activated by tumor-promotong phorbol esters, and appeared to belong to the group of PKC isozymes which lack Ca2+ sensitivity. Human prostatic PKC activity appeared to be of similar nature in both membrane and cytosolic fractions but the specific activity was higher in the particulate preparation which could be related to the stage of endogenous activation of the enzyme. These results extend previous observations in rat ventral prostate and present evidences on the human counterpart. Forthcoming experiments are needed to establish the exact nature of PKC isozymes and their physiological and pathophysiological role in this gland.
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Affiliation(s)
- P García-Paramio
- Departamento de Bioquímica y Biología Molecular, Universidad de Alcalá, Alcalá de Henares, Spain
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23
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Garcia-Paramio P, Carmena MJ, Gutierrez-Ocaña MT, Recio MN, Prieto JC. Alteration of protein kinase C activity in diabetic rat prostate. Biochem Biophys Res Commun 1993; 195:166-72. [PMID: 8363597 DOI: 10.1006/bbrc.1993.2025] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Protein kinase C activity is present in rat prostatic epithelial cells in both cytosolic and membrane subcellular fractions. Partial purification by ion-exchange chromatography and characterization of cofactor requirements showed its behavior as a classical Ca(2+)- and phospholipid-dependent enzyme activated by 1,2-diacylglycerol (or by mimicking agents such as tumor-promoting phorbol esters). Streptozotocin-induced diabetes resulted in an increase of the membrane/cytosolic enzyme ratio suggesting a redistribution of protein kinase C from the cytosolic to the membrane fraction (an index of enzyme activation) that could be reversed toward control conditions by insulin treatment. Differences observed in cofactor requirements for maximal enzyme activation argue for a some distinct expression of protein kinase C isozymes in control and diabetic conditions. These results are a new aspect of the complex set of alterations exhibited by the diabetic prostate in the signal transduction mechanisms that mediate cell functions and proliferation in this gland which could be related to the prostate atrophy and impaired fertility characteristic of this disease.
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Affiliation(s)
- P Garcia-Paramio
- Departamento de Bioquímica y Biología Molecular, Universidad de Alcalá, Alcalá de Henares, Spain
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24
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Abstract
The presence of tumor-promoting phorbol ester receptors in rat prostate was investigated by studying the binding of phorbol diester 12,13-dibutyrate (PDBu) in both soluble and particulate subcellular fractions. Binding of [3H]PDBu to the soluble fraction was optimal after the addition of phosphatidylserine (0.1 mg/ml) and Ca2+ (1 mM). Both subcellular fractions exhibited a single class of PDBu receptor (Kd between 97 and 128 nM) as shown by saturation binding experiments. Phorbol esters with tumor-promoting activity showed a higher affinity for these receptors than did endogenous ligands such as diacylglycerols whereas phorbol esters without tumor-promoting activity were ineffective even at concentrations as high as 1 microM. These properties are highly representative of protein kinase C activity.
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Affiliation(s)
- M J Carmena
- Departamento de Bioquímica y Biología Molecular, Universidad de Alcalá, Alcalá de Henares, Spain
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25
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Carmena MJ, Hueso C, Solano RM, Prieto JC. Differential effect of arachidonic acid on the vasoactive intestinal peptide receptor/effector system in rat prostatic epithelium during sexual maturation. Peptides 1992; 13:1117-22. [PMID: 1337377 DOI: 10.1016/0196-9781(92)90016-v] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The effects of alterations in the membrane lipid environment on vasoactive intestinal peptide (VIP) binding and VIP-stimulated cyclic AMP accumulation have been analyzed by arachidonic acid treatment of prostatic epithelial cells from rats at puberty and maturity, two critical developmental periods with characteristic lipidic and androgenic statuses. Treating cells with 0.1 mM arachidonic acid for 15 min at 37 degrees C increased the affinity of VIP receptors and the potency of the neuropeptide (up to five times) in the formation of cyclic AMP at maturity, but not at puberty. The average plasma membrane fluidity (as measured by fluorescence polarization of diphenylhexatriene) remained unmodified after arachidonic acid treatment of cells. The modifications observed in mature rats were specific for the VIP receptor/effector system, since cyclic AMP stimulation by isoproterenol or forskolin was not affected by cell treatment with arachidonic acid. These results are compatible with the existence of a particular lipidic microdomain surrounding the VIP receptor in the cell membrane that would be altered by exposure to arachidonic acid (either directly or through conversion of arachidonic acid to its metabolites, as suggested by experiments on inhibition of the arachidonic acid cascade). This would make it possible for the activation of protein kinase C to phosphorylate VIP receptors in cells from mature rats, but not in those from pubertal animals with a very different membrane lipid composition (as suggested by the corresponding values of membrane fluidity and transition temperature).
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Affiliation(s)
- M J Carmena
- Departamento de Bioquímica y Biología Molecular, Universidad de Alcalá, Alcalá de Henares Madrid, Spain
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26
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Carmena MJ, Clemente C, Guijarro LG, Prieto JC. The effect of streptozotocin diabetes on the vasoactive intestinal peptide receptor/effector system in membranes from rat ventral prostate. Endocrinology 1992; 131:1993-8. [PMID: 1327726 DOI: 10.1210/endo.131.4.1327726] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
All of the components of the neuropeptide vasoactive intestinal peptide (VIP) signal transduction system were underexpressed in rat prostatic membranes 6 weeks after streptozotocin-induced diabetes. Binding studies with [125I]VIP showed decreases of 86% and 62% in the binding capacity of the high and low affinity classes of VIP receptors in diabetes. Affinity labeling experiments indicated that the main form of VIP receptor was 51 kilodaltons in control rats and 45 kilodaltons in diabetic animals. The efficacy of VIP and forskolin in stimulation of adenylyl cyclase activity as well as the potentiating effect of GTP on VIP action were also reduced in diabetes, as was the expression of the alpha-subunit of the guanine nucleotide-binding regulatory proteins Gs and Gi (studied by ADP ribosylation with cholera and pertussis toxins). Gi function was lost in diabetes, as assessed with experiments on guanyl-5'-yl-imidodiphosphate potentiation of forskolin activity. These disturbances together with previous findings argue for VIP playing a role in the diabetic neuropathy of the genitourinary tract.
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Affiliation(s)
- M J Carmena
- Departamento de Bioquímica y Biología Molecular, Universidad de Alcalá, Spain
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27
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García-Paramio MP, Carmena MJ, Prieto JC. Up-modulation of phorbol dibutyrate receptors by carbachol and arachidonic acid in rat prostatic epithelial cells. Biosci Rep 1991; 11:189-94. [PMID: 1760527 DOI: 10.1007/bf01136852] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Phorbol dibutyrate (PDBu) binding to rat prostatic epithelial cells has been measured as an indirect determination of protein kinase C in this cell system. Analysis of [3H]PDBu binding using competitive displacement demonstrated a single class of PDBu receptors with a Kd = 141 nM and a binding capacity of 4.8 pmol PDBu bound/mg cell protein. Raising cytosolic Ca2+ levels by redistribution of intracellular Ca2+ after cell treatment with carbachol or arachidonic acid (which also affects the bulk biophysical properties of the cell membrane) resulted in up-regulation of the available number of PDBu receptors. These results appear to be a consequence of PKC translocation from the cytosolic compartment to the plasma membrane after a cytosolic Ca2+ increase, confirming previous results in other cell systems.
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Affiliation(s)
- M P García-Paramio
- Departamento de Bioquimica y Biología Molecular, Universidad de Alcalá, Madrid, Spain
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28
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Carmena MJ, Hueso C, Guijarro LG, Prieto JC. Cholesterol modulation of membrane fluidity and VIP receptor/effector system in rat prostatic epithelial cells. Regul Pept 1991; 33:287-97. [PMID: 1652781 DOI: 10.1016/0167-0115(91)90231-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Treatment of rat prostatic epithelial cells with cholesteryl hemisuccinate (ChH) resulted in a time- and dose-dependent inhibition of the stimulatory effect of the neuropeptide vasoactive intestinal peptide (VIP) on cyclic AMP accumulation, with a 40% decrease in the response to a maximally effective VIP concentration. Cell treatment with ChH led also to a similar blocking of isoproterenol (a beta-adrenergic agonist) action but did not modify forskolin (which is assumed to act directly on the catalytic unit of adenylate cyclase) activity upon cyclic AMP levels. The levels of the transduction protein Gs were similar in membranes from both control and ChH-treated cells as suggested by experiments on cholera toxin-catalyzed ADP-ribosylation. The inhibitory effect of ChH was accompanied by an increase of membrane microviscosity as estimated by measurements of fluorescence polarization. Experiments on VIP binding indicated that increasing cholesterol concentration in the plasma membrane led to a higher VIP binding capacity without changes in the affinity of VIP receptors. These data suggest that membrane cholesterol incorporation diminishes the coupling efficiency between adenylate cyclase and the VIP-receptor complex or other receptor systems (i.e., desensitization) due to an increase of plasma membrane rigidity.
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Affiliation(s)
- M J Carmena
- Departamento de Bioquímica y Biología Molecular, Universidad de Alcalá, Spain
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29
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López-Aparicio P, Recio MN, Prieto JC, Carmena MJ, Pérez-Albarsanz MA. Effect of lindane upon the beta-adrenergic stimulation of cyclic AMP accumulation in rat renal cortical tubules caused by alterations in membrane fluidity. Life Sci 1991; 49:1141-54. [PMID: 1716718 DOI: 10.1016/0024-3205(91)90561-o] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The influence of lindane (gamma-hexachlorocyclohexane) on fluidity and lipid composition in rat renal cortical tubules has been investigated. Lindane increased membrane fluidity as measured by a fluorescence polarization technique using the probe diphenylhexatriene. This effect was dose-dependent and was accompanied by a 70% inhibition of the beta-adrenergic stimulatory activity upon cyclic AMP accumulation after 30 min of preincubation with lindane at 25 degrees C. Experiments with increasing concentrations of isoproterenol indicated that the efficacy, but not the potency, of the beta-adrenergic effect upon cyclic AMP accumulation was affected by lindane. Lindane toxicity could also be associated with variations in the incorporation of acetate into various lipid classes. Lindane increased acetate incorporation into phospholipids and decreased that into cholesterol.
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Affiliation(s)
- P López-Aparicio
- Departamento de Bioquímica y Biología Molecular, Universidad de Alcalá, Alcalá de Henares-Madrid, Spain
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30
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Carmena MJ, Hueso C, Recio MN, Prieto JC. Beta-adrenergic stimulation of cyclic AMP accumulation in rat prostatic epithelial cells during sexual maturation. Mech Ageing Dev 1990; 52:79-86. [PMID: 1969011 DOI: 10.1016/0047-6374(90)90146-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The effect of age, castration and androgen-replacement therapy upon the stimulatory activity of the beta-adrenergic agonist isoproterenol on cyclic AMP accumulation was determined in rat prostatic epithelial cells. The potency of isoproterenol was similar in all the experimental models (ED50 = 0.3-0.4 microM). Mature animals showed a lower efficiency of isoproterenol than that of pubertal rats. Pubertal rats (which are absolutely dependent on androgens) exhibited an increase of the responsiveness of prostatic cyclic AMP to isoproterenol after castration, normalization being reached after subsequent testosterone treatment; this feature could be reproduced by in vitro incubation of the corresponding cells with testosterone or dihydrotestosterone. Mature rats (which are relatively dependent on androgens) maintained the efficiency of isoproterenol upon prostatic cyclic AMP after castration, and testosterone therapy elicited an increase of this activity. The present study contributes original observations mainly in the puberty period and supports the importance of the androgenic status not only for direct actions of androgens but also for the regulation of many other hormone/neurotransmitter/growth factor receptor-effector systems.
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Affiliation(s)
- M J Carmena
- Departamento de Bioquimica y Biologia Molecular, Universidad de Alcala, Alcala de Henares-Madrid, Spain
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31
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Prieto JC, Hueso C, Carmena MJ. Modulation of the beta-adrenergic stimulation of cyclic AMP accumulation in rat prostatic epithelial cells by membrane fluidity. Gen Pharmacol 1990; 21:931-3. [PMID: 2177713 DOI: 10.1016/0306-3623(90)90457-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
1. The influence of membrane lipid composition on the beta-adrenergic stimulation of cyclic AMP accumulation in rat prostatic epithelial cells was assessed after treating the cells with cholesteryl hemisuccinate (ChH). 2. ChH treatment resulted in a 40% inhibition of the beta-adrenergic response after 30 min of lipid preincubation at 37 degrees C. 3. The inhibitory effect of ChH was dose-dependent and was accompanied by an increase of microviscosity as measured by a fluorescence polarization technique with the probe diphenylhexatriene. 4. Experiments with increasing concentrations of isoproterenol indicated that the efficiency, but not the potency, of the beta-adrenergic response was affected by the increasing of the cholesterol content in the cell membrane.
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Affiliation(s)
- J C Prieto
- Departamento de Bioquímica y Biología Molecular, Universidad de Alcalá, Spain
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Hueso C, Carmena MJ, Prieto JC. Identification of specific binding sites for vasoactive intestinal peptide in rat testis Leydig cells and study of developmental changes. Biochem Int 1989; 19:951-8. [PMID: 2635855] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The interaction of vasoactive intestinal peptide (VIP) with isolated Leydig cells from rat testis was time- and temperature-dependent, as well as saturable and specific. Scatchard analysis suggested the presence of both high- and low-affinity binding sites with KD values of 1.7 and 43 nM, respectively, and receptor concentrations of 35 and 1394 fmol VIP bound/mg protein in mature (3- to 6-month old) rats. When considering pubertal (45-day old) rats, the affinities were similar but the binding capacities showed considerably lower values (25 and 193 fmol VIP bound/mg protein) indicating that VIP receptors are subject to developmental changes during animal maturation.
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Affiliation(s)
- C Hueso
- Departamento de Bioquímica y Biología Molecular, Universidad de Alcalá, Alcalá de Henares-Madrid, Spain
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Carmena MJ, Escudero F, Prieto JC. Inhibitory action of tumor-promoting phorbol esters upon beta-adrenergic agonist stimulation of cyclic AMP accumulation in rat prostatic epithelial cells. Biochem Int 1988; 17:427-32. [PMID: 2904816] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The pretreatment of rat prostatic epithelial cells with 4 beta-phorbol 12-myristate 13-acetate resulted in an attenuation of beta-adrenergic stimulated cyclic AMP accumulation. The effect was dependent on time and concentration. The maximal extent of isoproterenol stimulation of cyclic AMP production was reduced by 35% after 15-min pretreatment with the phorbol ester at 25 degrees C. Since a similar action was exerted by other protein kinase C stimulators, present results suggest the involvement of this enzyme in a process of desensitization to beta-adrenergic agonists of the adenylate cyclase system in rat prostatic epithelium.
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Affiliation(s)
- M J Carmena
- Departamento de Bioquímica y Biología Molecular, Universidad de Alcala, Madrid, Spain
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Carmena MJ, Recio MN, Prieto JC. Influence of castration and testosterone treatment on the vasoactive intestinal peptide receptor/effector system in rat prostatic epithelial cells. Biochim Biophys Acta 1988; 969:86-90. [PMID: 2832001 DOI: 10.1016/0167-4889(88)90091-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The interaction of vasoactive intestinal peptide (VIP) with prostatic epithelial cells was studied after castration and testosterone replacement in pubertal and mature rats. The number of VIP receptors (but not the affinity) decreased 2 days after castration and returned to normal when subsequently treated with testosterone for 4 days. However, the stimulatory effect of VIP upon cyclic AMP accumulation was unaffected by the androgen withdrawal elicited by the surgical procedure. The results suggest the importance of androgens in the biosynthesis of VIP receptors and also in their coupling to adenylate cyclase by affecting the membrane fluidity.
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Affiliation(s)
- M J Carmena
- Departamento de Bioquímica, Universidad de Alcalá de Henares, Madrid, Spain
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Escudero F, Carmena MJ, Prieto JC. Tumor-promoting phorbol esters interfere with the vasoactive intestinal peptide receptor/effector system in rat prostatic epithelial cells. Biochem Biophys Res Commun 1987; 149:221-6. [PMID: 2825698 DOI: 10.1016/0006-291x(87)91627-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Pretreatment of rat prostatic epithelial cells with the tumor-promoting phorbol ester 4 beta-phorbol 12-myristate 13-acetate resulted in a decrease of both the potency of vasoactive intestinal peptide (VIP) upon the stimulation of cyclic AMP accumulation and the affinity of the receptors of this peptide. These effects were dose-dependent and could be reproduced by other stimulators of protein kinase C (PKC). Thus, it is conceivably that phosphorylation of VIP receptors by PKC regulates VIP receptor function in the prostate gland.
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Affiliation(s)
- F Escudero
- Departamento de Bioquímica y Biología Molecular, Universidad de Alcalá de Henares, Madrid, Spain
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Hueso C, Carmena MJ, Prieto JC. Characterization and age dependence of the stimulatory effect of VIP on cyclic AMP accumulation in rat Leydig cells. Biosci Rep 1987; 7:805-11. [PMID: 2833954 DOI: 10.1007/bf01116754] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
The neuropeptide vasoactive intestinal peptide (VIP) has been shown to stimulate cyclic AMP accumulation in Leydig cells isolated from rat testis. The effect was dependent on time, temperature and cell concentration. At 15 degrees C, half-maximal and maximal stimulation were observed at about 1 and 100 nM VIP, respectively. The interaction was specific since an order of potencies chicken VIP greater than rat VIP greater than secretin greater than glucagon and no effect of neurotensin and substance P were obtained. The efficiency of VIP was lower in pubertal rats and then increased in young-adult and adult animals. These results together with the known presence of VIP in the testis support the idea that VIP may be involved in the regulation and function of Leydig cells during development.
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Affiliation(s)
- C Hueso
- Departamento de Bioquímica y Biología Molecular, Universidad de Alcalá de Henares, Madrid, Spain
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Carmena MJ, Sancho JI, Fernández-González MA, Escudero F, Prieto JC. Somatostatin inhibits VIP- and isoproterenol-stimulated cyclic AMP accumulation in rat prostatic epithelial cells. FEBS Lett 1987; 218:73-6. [PMID: 2885224 DOI: 10.1016/0014-5793(87)81021-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The dual regulation of cyclic AMP accumulation was studied in rat prostatic epithelial cells incubated with somatostatin, vasoactive intestinal peptide (VIP), and the beta-adrenergic agent isoproterenol. Somatostatin noncompetitively inhibited the stimulatory effect of VIP and isoproterenol, but it did not alter basal cyclic AMP levels. In addition to the multifactorial regulation of the cyclic AMP system in rat prostatic epithelium, these results suggest that somatostatin may play a physiological role at this level.
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Carmena MJ, Prieto JC, Arilla E, Cacicedo L. Effect of gastroduodenostomy on intestinal vasoactive intestinal peptide (VIP) levels, and VIP binding and VIP stimulation of cyclic AMP in intestinal epithelial cells from rat. Biochem Med Metab Biol 1987; 37:307-13. [PMID: 2440464 DOI: 10.1016/0885-4505(87)90041-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The concentration of VIP in duodenum and jejunum as well as the interaction of VIP (binding and stimulation of cyclic AMP accumulation) with epithelial cells from both gut segments were studied in rats after surgical bypass of the pylorus by gastroduodenostomy. Duodenal VIP concentration increased in rats with gastroduodenostomy as compared to sham-operated animals. The binding capacity (but not the affinity) of VIP binding sites and the efficiency (but not the potency) of VIP on cyclic AMP accumulation decreased in the condition of gastroduodenostomy. However, no modifications in either VIP concentration and interaction could be seen at the jejunal level.
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Abstract
The binding of [125I]-human growth hormone (hGH) was studied in epithelial cells isolated from rat ventral prostate. Binding and degradation were dependent on time and temperature. The effect of a lysosomotropic agent suggested internalization and lysosomal degradation of the hormone. Dissociation and stoichiometric studies indicated the existence of a single class of GH receptors with a Kd of 0.7 nM and a binding capacity of 46 fmol hGH bound mg-1 cell protein. The receptor appeared to possess a somatotrophic nature since lactogenic hormones such as human placental lactogen and rat prolactin exhibited a very low degree of competition (whereas a variety of unrelated hormones and neuropeptides showed no effect). GH-stimulated leucine uptake by the cells in a time- and dose-dependent manner, half maximal effect being observed at 0.32 nM GH thus suggesting a direct relationship with the binding step.
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Fernandez-Gonzalez MA, Barrios V, Sancho JI, Arilla E, Carmena MJ, Tresguerres JA, Prieto JC. Tissue and plasma distribution of exogenous growth hormone-releasing factor analogue (GRF1-29NH2) after intravenous, subcutaneous and intraperitoneal injection in the rat. Gen Pharmacol 1987; 18:551-4. [PMID: 2888706 DOI: 10.1016/0306-3623(87)90079-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
1. The administration of 125I-labelled growth hormone-releasing factor (GRF) analogue 1-29NH2 by intravenous, subcutaneous or intraperitoneal injection to rats leads to rapid (i.v.) or slow (s.c. and i.p.) increases in plasma radioactivity followed by extensive breakdown of the peptide. 2. Tissues possessing GRF-like immunoreactivity such as gastric antrum (but not fundus), duodenum and ileum showed in vitro specific uptake of 125I-GRF probably mediated by vasoactive intestinal peptide (VIP) receptors. 3. Pituitary (the primary target organ for GRF) but neither thyroid nor parathyroid exhibited specific uptake of 125I-GRF.
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Affiliation(s)
- M A Fernandez-Gonzalez
- Departamento de Bioquímica y Biología Molecular, Universidad de Alcalá de Henares, Spain
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Carmena MJ, Sancho JI, Prieto JC. Effects of age and androgens upon functional vasoactive intestinal peptide receptors in rat prostatic epithelial cells. Biochim Biophys Acta 1986; 888:338-43. [PMID: 3019425 DOI: 10.1016/0167-4889(86)90234-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The specific binding of vasoactive intestinal peptide (VIP) and the stimulatory effect of VIP upon cyclic AMP accumulation in isolated epithelial cells of rat ventral prostate were age dependent. The number of VIP receptors decreased but the efficiency of VIP on cyclic AMP accumulation increased in prostatic epithelium when considering the periods 35-65 days and 3-6 months. Since these features could be related to the known age-related decrease of androgen and androgen-receptor levels, we studied the effect of testosterone and its 5 alpha-reduced metabolite dihydrotestosterone upon both steps of VIP action. The two steroid hormones exerted a non-competitive inhibition on VIP-induced cyclic AMP accumulation but did not modify VIP binding to its specific receptors. This modulatory effect of androgens might involve their interaction with specific sites on the cell membrane leading to modifications of membrane activities including adenylate cyclase, as has been suggested by an increasing number of recent reports.
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Carmena MJ, Sancho JI, Prieto JC. Additive effect of VIP or isoproterenol on forskolin-stimulated cyclic AMP accumulation in rat prostatic epithelial cells. Biochem Int 1986; 13:479-85. [PMID: 3024642] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The effects of forskolin alone or in combination with vasoactive intestinal peptide (VIP) and the beta-adrenergic agonist isoproterenol on cyclic AMP accumulation in epithelial cells of rat ventral prostate were examined. Forskolin stimulated cyclic AMP in a time- and temperature-dependent manner. At 15 degrees C, forskolin behaved as a highly potent and relatively efficient stimulatory agent. The combination of forskolin with maximal doses of VIP or isoproterenol were purely additive. These results suggest that forskolin might act directly upon the catalytic subunit of adenylate cyclase in this particular class of cells.
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Carmena MJ, Fernandez-Moreno MD, Prieto JC. Characterization of insulin receptors in isolated epithelial cells of rat ventral prostate: effect of fasting. Cell Biochem Funct 1986; 4:19-24. [PMID: 3510753 DOI: 10.1002/cbf.290040103] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Insulin receptors have been characterized in rat prostatic epithelial cells by using [125I]insulin and a variety of physicochemical conditions. The binding data at equilibrium (2 h at 15 degrees C) could be interpreted in terms of two populations of insulin receptors: a class of receptors with high affinity (Kd = 2.16 nM) and low binding capacity (28.0 fmol mg-1 protein), and another class of receptors with low affinity (Kd = 0.29 microM) and high binding capacity (1.43 pmol mg-1 protein). Proinsulin exhibited a 63-fold lower affinity than insulin for binding sites whereas unrelated peptides were ineffective. The specific binding of insulin increased by about 50 per cent after 96 h of fasting; this increase could be explained by an increase of both the number of the high affinity-low capacity sites and the affinity of the low affinity-high capacity sites. These results together with previous studies on insulin action at the prostatic level strongly suggest that insulin may exert a physiological role on the prostatic epithelium.
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Carmena MJ, Prieto JC. Cyclic AMP response to vasoactive intestinal peptide and beta-adrenergic or cholinergic agonists in isolated epithelial cells of rat ventral prostate. Biosci Rep 1985; 5:791-7. [PMID: 3002512 DOI: 10.1007/bf01119878] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Vasoactive intestinal peptide (VIP) and the beta-adrenergic agonist isoproterenol stimulated cyclic AMP formation through independent receptors in isolated epithelial cells of rat ventral prostate. The specific beta-adrenergic antagonist propranolol inhibited the stimulatory effect of isoproterenol but not that of VIP. Besides small differences in the efficiency of both agents, results indicated that isoproterenol was 500 times less potent than VIP. Acetylcholine did not modify the basal cyclic AMP levels but inhibited the accumulation of the cyclic nucleotide in the presence of either VIP or isoproterenol. The inhibitory action of muscarinic receptors was calcium-dependent. The coexistence of receptors for cholinergic, adrenergic and peptidergic agents which can regulate cyclic AMP suggests that the functions of prostatic epithelium may be interdependently controlled by multiple neural effectors.
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Abstract
Specific binding of vasoactive intestinal peptide (VIP) to epithelial cell membranes of rat ventral prostate was reversible, saturable and dependent on time and temperature. The data suggested the presence of two classes of VIP receptors: a class with high affinity (Kd = 1.7 nM) and low binding capacity (0.5 pmol VIP/mg protein), and another class with low affinity (Kd = 36.2 nM) and high binding capacity (7.5 pmol VIP/mg protein). Chicken VIP and porcine secretin recognized VIP receptors but exhibited a 10-fold higher and a 40-fold lower affinity than porcine VIP, respectively. However, glucagon, somatostatin, Met-enkephalin and cholecystokinin were ineffective. GTP inhibited markedly the interaction of VIP with membranes by increasing the rate of dissociation of peptide bound to its receptors. GDP and Gpp(NH)p behaved as GTP but other purine nucleotides and nucleosides did not show any effect.
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Recio MN, Del Hoyo N, Carmena MJ, Perez-Albarsanz MA. In vitro age-dependent incorporation of [1-14C]acetate into lipid subclasses in rat ventral prostate. Int J Biochem 1985; 17:1129-32. [PMID: 4065402 DOI: 10.1016/0020-711x(85)90048-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The [1-14C]acetate incorporation into different lipid subclasses by the rat prostate gland was lineal between 20 and 80 mg of wet tissue. The in vitro [1-14C]acetate incorporation into lipid subclasses was a development-dependent process. The highest values of [1-14C]acetate incorporation into triacylglycerols, free cholesterol and esterified cholesterol were observed at puberty, but radioactivity incorporation into phospholipids was similar in both prepuberty and puberty, then decreasing in maturity. The relationship between triacylglycerols, free cholesterol and esterified cholesterol with respect to total lipids was about 12, 10 and 3.5%, respectively, values being maintained during the animal development. The in vitro [1-14C]acetate incorporation into lipid subclasses in castrated rats decreased considerably as compared with normal rats.
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Carmena MJ, Perez-Albarsanz MA, Recio MN. [1-14C]acetate incorporation into free and esterified cholesterol during the development of the rat ventral prostate. Comp Biochem Physiol B 1984; 79:633-6. [PMID: 6518766 DOI: 10.1016/0305-0491(84)90377-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The in vivo [1-14C]acetate incorporation into free and esterified cholesterol in rat ventral prostate depends on the animal developmental process, and it is the highest in the puberty stage. The relationship between free cholesterol and total lipids is 12-14% and that between esterified cholesterol and total lipids is 4-5%, both of the two being maintained during the animal development. The [1-14C]-acetate incorporation into free and esterified cholesterol in castrated animals decreases as compared with that in normal rats and it does not depend on the age of the animal.
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Prieto JC, Carmena MJ. Receptors for vasoactive intestinal peptide on isolated epithelial cells of rat ventral prostate. Biochim Biophys Acta 1983; 763:408-13. [PMID: 6317051 DOI: 10.1016/0167-4889(83)90102-7] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Receptors for porcine vasoactive intestinal peptide have been characterized in isolated epithelial cells of rat ventral prostate. The interaction of 125I-labelled VIP with cells was rapid, reversible, specific, saturable and dependent on temperature. Degradation of peptide and receptors was minimized at 15 degrees C. At apparent equilibrium, the binding of 125I-labelled peptide was competitively inhibited by native VIP in the 1 X 10(-10)-10(-7)M range concentration. The binding data were compatible with the existence of two classes of receptors: a high-affinity class with a Kd = 4.0 nM and a low binding capacity (0.12 pmol VIP/mg cell protein), and a low-affinity class with a Kd = 17.8 nM and a high binding capacity (1.6 pmol VIP/mg cell protein). Chicken VIP and porcine secretin exhibited a 7-fold higher and a 7-fold lower affinity than porcine VIP for binding sites, respectively. Glucagon, Leu-enkephalin, Met-enkephalin and somatostatin were ineffective. The presence of high-affinity receptors for VIP together with previous reports on the occurrence of VIP-containing neurones innervating the male genitourinary tract strongly suggest that this peptide may be important in the physiological regulation of the functions of prostatic epithelium.
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Carmena MJ, Prieto JC. Cyclic AMP-stimulating effect of vasoactive intestinal peptide in isolated epithelial cells of rat ventral prostate. Biochim Biophys Acta 1983; 763:414-8. [PMID: 6317052 DOI: 10.1016/0167-4889(83)90103-9] [Citation(s) in RCA: 36] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Vasoactive intestinal peptide (VIP) has been shown to increase cyclic AMP content in isolated epithelial cells of rat ventral prostate. The stimulatory effect of VIP was dependent on time and temperature and was potentiated by a phosphodiesterase inhibitor. At 15 degrees C, the response occurred in the 1 X 10(-10)-10(-7)M range of VIP concentrations. Half-maximal stimulation of cellular cyclic AMP was obtained at 1.4 nM and maximal stimulation (3-fold basal level) at about 100 nM VIP. Chicken VIP and porcine secretin were agonists of porcine VIP but exhibited a 2-times higher and a 170-times lower potency, respectively. A high concentration (1 X 10(-6)M) of glucagon, somatostatin, neurotensin, substance P, Met-enkephalin or Leu-enkephalin did not modify cAMP levels. The finding of a VIP-stimulated cAMP system in rat prostatic epithelial cells together with the previous characterization of high-affinity receptors for VIP in the same cell preparation, as well as the presence of VIP-containing neurones innervating the male genitourinary tract, strongly suggest that VIP may be involved in prostatic growth regulation and function.
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