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Eugster PJ, Dunand M, Grund B, Ivanyuk A, Fogarasi Szabo N, Bardinet C, Abid K, Buclin T, Grouzmann E, Chtioui H. Quantification of serotonin and eight of its metabolites in plasma of healthy volunteers by mass spectrometry. Clin Chim Acta 2022; 535:19-26. [PMID: 35963304 DOI: 10.1016/j.cca.2022.08.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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: 06/23/2022] [Revised: 08/05/2022] [Accepted: 08/08/2022] [Indexed: 11/15/2022]
Abstract
Serotonin is transformed into melatonin under the control of the light/dark cycle, representing a cornerstone of circadian rhythmicity. Serotonin also undergoes extensive metabolism to produce 5-hydroxyindoleacetic acid (5-HIAA), a biomarker for the diagnosis and monitoring of serotonin secreting neuroendocrine tumors (NETs). While serotonin, melatonin and their metabolites are part of an integrated comprehensive system, human observations about their respective plasma concentrations are still limited. We report here for the first time a multiplex UHPLC-MS/MS assay for the quantification of serotonin, 5-HIAA, 5-hydroxytryptophol (5-HTPL), N-acetyl-serotonin (NAS), Mel, 6-OH-Mel, 5-methoxytryptamine (5-MT), 5-methoxytryptophol (5-MTPL), and 5-methoxyindoleacetic acid (5-MIAA) in human plasma. Analytes were extracted by protein precipitation and solid phase extraction. Plasma concentrations for these analytes were determined in 102 healthy volunteers. The LLOQ of the assay ranges from 2.2 nM for serotonin to 1.0 pM for 6-OH-Mel. This sensitivity enables the quantification of circulating serotonin, 5-HIAA, NAS, Mel, and 5-MIAA, even at their lowest diurnal concentrations. This assay will enable specific, precise and accurate measurement of serotonin, Mel and their metabolites to draw a detailed picture of this complex pineal metabolism, allowing a dynamic understanding of these pathways and providing promising biomarkers and a metabolic signature for serotonin-secreting NETs.
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Affiliation(s)
- Philippe J Eugster
- Service of Clinical Pharmacology, Lausanne University Hospital and University of Lausanne, Switzerland.
| | - Marielle Dunand
- Service of Clinical Pharmacology, Lausanne University Hospital and University of Lausanne, Switzerland
| | - Baptiste Grund
- Service of Clinical Pharmacology, Lausanne University Hospital and University of Lausanne, Switzerland
| | - Anton Ivanyuk
- Service of Clinical Pharmacology, Lausanne University Hospital and University of Lausanne, Switzerland
| | - Nathalie Fogarasi Szabo
- Service of Clinical Pharmacology, Lausanne University Hospital and University of Lausanne, Switzerland
| | - Carine Bardinet
- Service of Clinical Pharmacology, Lausanne University Hospital and University of Lausanne, Switzerland
| | - Karim Abid
- Service of Clinical Pharmacology, Lausanne University Hospital and University of Lausanne, Switzerland
| | - Thierry Buclin
- Service of Clinical Pharmacology, Lausanne University Hospital and University of Lausanne, Switzerland
| | - Eric Grouzmann
- Service of Clinical Pharmacology, Lausanne University Hospital and University of Lausanne, Switzerland
| | - Haithem Chtioui
- Service of Clinical Pharmacology, Lausanne University Hospital and University of Lausanne, Switzerland
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Vocat C, Dunand M, Hubers SA, Bourdillon N, Millet GP, Brown NJ, Wuerzner G, Grouzmann E, Eugster PJ. Quantification of Neuropeptide Y and Four of Its Metabolites in Human Plasma by Micro-UHPLC-MS/MS. Anal Chem 2020; 92:859-866. [PMID: 31790196 PMCID: PMC8541045 DOI: 10.1021/acs.analchem.9b03505] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Neuropeptide Y (NPY) is a 36-amino acid peptide circulating at a subpicomolar concentration participating in multiple physiological and pathological processes. NPY is prone to peptidolysis, generating metabolites with modified affinity for the five known receptors of NPY that mediate distinct effects. It is, therefore, crucial to distinguish each metabolite to understand the multiple functions of NPY. Since immunoassays are not able to distinguish NPY from its metabolites, we have validated a microliquid chromatography tandem mass spectrometry (micro-LC-MS/MS) assay for the quantification of endogenous NPY, NPY2-36, NPY3-36, NPY1-35, and NPY3-35 in human plasma. Sample preparation relies on immunoextraction in 96-well plates, followed by solid-phase extraction prior to micro-LC-MS/MS. The LLOQ ranged from 0.03 to 0.16 pM, intra- and inter-assay precision were <27% and trueness <22%. We determined reference intervals in 155 healthy volunteers and 40 hypertensive patients. We found that NPY3-36 is the main circulating peptide in resting conditions and that NPY and catecholamines are simultaneously increased during orthostasis. We also showed that the concentrations of NPY and its metabolites are similar in healthy volunteers and hypertensive patients. NPY is the prototype peptide that circulates in concentrations expected to be beyond instrumental capacities. We have been successful in developing a high-throughput specific and sensitive assay by including a deep knowledge of the physicochemical properties of these peptides to an efficient multistep sample preparation, and a micro-LC chromatography. We believe that our methodological approach opens the possibility to selectively quantify other endogenous peptides cleaved by peptidases whose concentrations are below 1 pM.
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Affiliation(s)
- Céline Vocat
- Service of Clinical Pharmacology, Lausanne University Hospital and University of Lausanne, 1011 Lausanne, Switzerland
| | - Marielle Dunand
- Service of Clinical Pharmacology, Lausanne University Hospital and University of Lausanne, 1011 Lausanne, Switzerland
| | - Scott A. Hubers
- Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
| | - Nicolas Bourdillon
- Institute of Sport Sciences (ISSUL), University of Lausanne, 1015 Lausanne, Switzerland
| | - Grégoire P. Millet
- Institute of Sport Sciences (ISSUL), University of Lausanne, 1015 Lausanne, Switzerland
| | - Nancy J. Brown
- Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
| | - Grégoire Wuerzner
- Service of Nephrology and Hypertension, Lausanne University Hospital and University of Lausanne, 1011 Lausanne, Switzerland
| | - Eric Grouzmann
- Service of Clinical Pharmacology, Lausanne University Hospital and University of Lausanne, 1011 Lausanne, Switzerland
| | - Philippe J. Eugster
- Service of Clinical Pharmacology, Lausanne University Hospital and University of Lausanne, 1011 Lausanne, Switzerland
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Eugster PJ, Chtioui H, Herren A, Dunand M, Cappelle D, Bourquin J, Buclin T, Grouzmann E. Sub-picomolar quantification of PTH 1-34 in plasma by UHPLC-MS/MS after subcutaneous injection of teriparatide and identification of PTH 1-33, its degradation product. J Pharm Biomed Anal 2019; 166:205-212. [PMID: 30660035 DOI: 10.1016/j.jpba.2019.01.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [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: 11/02/2018] [Revised: 01/07/2019] [Accepted: 01/08/2019] [Indexed: 01/01/2023]
Abstract
Teriparatide (PTH 1-34, Forsteo®) is a bioactive N-terminal fragment of the native endogenous parathyroid hormone (PTH 1-84) recommended for the treatment of osteoporosis in patients with high risk of fracture. Since PTH 1-34 may undergo proteolysis we have validated an ultra-high pressure liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) method for unambiguously measuring intact PTH 1-34 with the same sensitivity as ELISA, at subpicomolar level (LLOQ at 0.4 pM). The full chromatographic run was achieved in 16.5 min. The method validation showed satisfactory intra- and inter-assay precision (CV < 13%) and excellent trueness (<5%), and almost no matrix effect (recoveries 78-92%). We found that after subcutaneous injection in two volunteers, PTH 1-34 half-life was shorter with UHPLC-MS/MS and that ELISA was overestimating PTH 1-34 late concentrations in both volunteers. Qualitative mass spectrometry was performed and led to the discovery of PTH 1-33, a fragment of PTH 1-34 with unknown function. This study emphasized the importance of switching from immunoassays to mass spectrometry when measuring bioactive peptides prompt to proteolysis into fragments that may exhibit altered bioactivity and duration of action.
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Affiliation(s)
- Philippe J Eugster
- Service of Clinical Pharmacology, Lausanne University Hospital (CHUV), Lausanne, Switzerland.
| | - Haithem Chtioui
- Service of Clinical Pharmacology, Lausanne University Hospital (CHUV), Lausanne, Switzerland
| | - Adeline Herren
- Service of Clinical Pharmacology, Lausanne University Hospital (CHUV), Lausanne, Switzerland
| | - Marielle Dunand
- Service of Clinical Pharmacology, Lausanne University Hospital (CHUV), Lausanne, Switzerland
| | - Delphine Cappelle
- Service of Clinical Pharmacology, Lausanne University Hospital (CHUV), Lausanne, Switzerland
| | - Julien Bourquin
- Waters Corporation, Stamford Avenue, Altrincham Road, Wilmslow, SK9 4AX, United Kingdom
| | - Thierry Buclin
- Service of Clinical Pharmacology, Lausanne University Hospital (CHUV), Lausanne, Switzerland
| | - Eric Grouzmann
- Service of Clinical Pharmacology, Lausanne University Hospital (CHUV), Lausanne, Switzerland
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Dunand M, Grund B, Eugster P, Ivanyuk A, Fogarasi-Szabo N, Bardinet C, Grouzmann E, Buclin T, Chtioui H. Serotonin, Melatonin and Their Metabolites Measured in Plasma by a New LC-MS/MS Assay In Healthy Volunteers. Clin Ther 2017. [DOI: 10.1016/j.clinthera.2017.05.127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Franscini LC, Vazquez-Montes M, Buclin T, Perera R, Dunand M, Grouzmann E, Beck-Popovic M. Pediatric reference intervals for plasma free and total metanephrines established with a parametric approach: relevance to the diagnosis of neuroblastoma. Pediatr Blood Cancer 2015; 62:587-93. [PMID: 25597761 DOI: 10.1002/pbc.25385] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2014] [Accepted: 11/04/2014] [Indexed: 11/07/2022]
Abstract
BACKGROUND Urine catecholamines, vanillylmandelic, and homovanillic acid are recognized biomarkers for the diagnosis and follow-up of neuroblastoma. Plasma free (f) and total (t) normetanephrine (NMN), metanephrine (MN) and methoxytyramine (MT) could represent a convenient alternative to those urine markers. The primary objective of this study was to establish pediatric centile charts for plasma metanephrines. Secondarily, we explored their diagnostic performance in 10 patients with neuroblastoma. PROCEDURE We recruited 191 children (69 females) free of neuroendocrine disease to establish reference intervals for plasma metanephrines, reported as centile curves for a given age and sex based on a parametric method using fractional polynomials models. Urine markers and plasma metanephrines were measured in 10 children with neuroblastoma at diagnosis. Plasma total metanephrines were measured by HPLC with coulometric detection and plasma free metanephrines by tandem LC-MS. RESULTS We observed a significant age-dependence for tNMN, fNMN, and fMN, and a gender and age-dependence for tMN, fNMN, and fMN. Free MT was below the lower limit of quantification in 94% of the children. All patients with neuroblastoma at diagnosis were above the 97.5th percentile for tMT, tNMN, fNMN, and fMT, whereas their fMN and tMN were mostly within the normal range. As expected, urine assays were inconstantly predictive of the disease. CONCLUSIONS A continuous model incorporating all data for a given analyte represents an appealing alternative to arbitrary partitioning of reference intervals across age categories. Plasma metanephrines are promising biomarkers for neuroblastoma, and their performances need to be confirmed in a prospective study on a large cohort of patients.
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Affiliation(s)
- Laura Crosazzo Franscini
- Department of Pediatrics, Unit of Hematology-Oncology, University Hospital, Lausanne, Switzerland
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Dunand M, Donzelli M, Rickli A, Hysek CM, Liechti ME, Grouzmann E. Analytical interference of 4-hydroxy-3-methoxymethamphetamine with the measurement of plasma free normetanephrine by ultra-high pressure liquid chromatography–tandem mass spectrometry. Clin Biochem 2014; 47:1121-3. [DOI: 10.1016/j.clinbiochem.2014.04.003] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2014] [Revised: 03/25/2014] [Accepted: 04/03/2014] [Indexed: 11/29/2022]
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Dunand M, Gubian D, Stauffer M, Abid K, Grouzmann E. High-Throughput and Sensitive Quantitation of Plasma Catecholamines by Ultraperformance Liquid Chromatography–Tandem Mass Spectrometry Using a Solid Phase Microwell Extraction Plate. Anal Chem 2013; 85:3539-44. [DOI: 10.1021/ac4004584] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Marielle Dunand
- Service de
Biomédecine, Laboratoire des Catécholamines et Peptides and ‡Maintenance Biomédicale
des Laboratoires, Centre Hospitalier Universitaire Vaudois, 1011, Lausanne, Switzerland
| | - Danilo Gubian
- Service de
Biomédecine, Laboratoire des Catécholamines et Peptides and ‡Maintenance Biomédicale
des Laboratoires, Centre Hospitalier Universitaire Vaudois, 1011, Lausanne, Switzerland
| | - Maxime Stauffer
- Service de
Biomédecine, Laboratoire des Catécholamines et Peptides and ‡Maintenance Biomédicale
des Laboratoires, Centre Hospitalier Universitaire Vaudois, 1011, Lausanne, Switzerland
| | - Karim Abid
- Service de
Biomédecine, Laboratoire des Catécholamines et Peptides and ‡Maintenance Biomédicale
des Laboratoires, Centre Hospitalier Universitaire Vaudois, 1011, Lausanne, Switzerland
| | - Eric Grouzmann
- Service de
Biomédecine, Laboratoire des Catécholamines et Peptides and ‡Maintenance Biomédicale
des Laboratoires, Centre Hospitalier Universitaire Vaudois, 1011, Lausanne, Switzerland
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Dunand M, Gary G, Mohr D. High strain rate tensile testing of sheet materials using three Hopkinson pressure bars. EPJ Web of Conferences 2012. [DOI: 10.1051/epjconf/20122601010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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9
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de Greef JC, Lemmers RJLF, Camaño P, Day JW, Sacconi S, Dunand M, van Engelen BGM, Kiuru-Enari S, Padberg GW, Rosa AL, Desnuelle C, Spuler S, Tarnopolsky M, Venance SL, Frants RR, van der Maarel SM, Tawil R. Clinical features of facioscapulohumeral muscular dystrophy 2. Neurology 2010; 75:1548-54. [PMID: 20975055 PMCID: PMC2974464 DOI: 10.1212/wnl.0b013e3181f96175] [Citation(s) in RCA: 145] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
OBJECTIVE In some 5% of patients with facioscapulohumeral muscular dystrophy (FSHD), no D4Z4 repeat contraction on chromosome 4q35 is observed. Such patients, termed patients with FSHD2, show loss of DNA methylation and heterochromatin markers at the D4Z4 repeat that are similar to patients with D4Z4 contractions (FSHD1). This commonality suggests that a change in D4Z4 chromatin structure unifies FSHD1 and FSHD2. The aim of our study was to critically evaluate the clinical features in patients with FSHD2 in order to establish whether these patients are phenotypically identical to FSHD1 and to establish the effects of the (epi-) genotype on the phenotype. METHODS This cross-sectional study studied 33 patients with FSHD2 from 27 families, the largest cohort described to date. All patients were clinically assessed using a standardized clinical evaluation form. Genotype analysis was performed by pulsed field gel electrophoresis and PCR; D4Z4 methylation was studied by methylation-sensitive Southern blot analysis. RESULTS FSHD2 is identical to FSHD1 in its clinical presentation. Notable differences include a higher incidence (67%) of sporadic cases and the absence of gender differences in disease severity in FSHD2. Overall, average disease severity in FSHD2 was similar to that reported in FSHD1 and was not influenced by D4Z4 repeat size. In FSHD2, a small effect of the degree of hypomethylation on disease severity was observed. CONCLUSIONS Clinically, patients with FSHD2 are indistinguishable from patients with FSHD1. The present data suggest that FSHD1 and FSHD2 are the result of the same pathophysiologic process.
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Affiliation(s)
- J C de Greef
- Department of Human Genetics, Leiden University Medical Center, Leiden, the Netherlands
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Dunand M, Borruat F, Botez S, Kuntzer T. M.P.1.11 Myasthenia gravis: Alternative reasons for unsatisfactory outcome evidenced by a prospective study. Neuromuscul Disord 2008. [DOI: 10.1016/j.nmd.2008.06.091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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11
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Dunand M, Lobrinus J, Richard P, Bernard R, Levy N, Kuntzer T. G.P.13.03 Familial late-onset inclusion body myositis in a search of a gene. Neuromuscul Disord 2007. [DOI: 10.1016/j.nmd.2007.06.295] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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12
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Ochsner F, Dunand M, Kuntzer T. J - 30 Myalgies d’effort et déficit en CPTII : prise en charge et prévisions thérapeutiques. Rev Neurol (Paris) 2007. [DOI: 10.1016/s0035-3787(07)90682-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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13
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Botez S, Carota A, Dunand M, Du Pasquier R, Kuntzer T, Michel P, Morier J, Schluep M, Rossetti AO. [Neurology]. Rev Med Suisse 2007; 3:39-47. [PMID: 17354660] [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: 05/14/2023]
Abstract
Neurology is a polymorphic discipline, with several subspecialties. In 2006, as in the previous years, a huge amount of scientific work focusing on treatment has been published. However, there has not been a true revolution in any of the current therapeutic strategies; rather, we experienced an improvement in the knowledge about several specific "details". This allows to consider more and more variables when administering a specific treatment, therefore, in each subspecialty a move towards a better patient's care has been made. In this contribution, several specialists analyse and interpret new facts about their respective neurological domain.
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Affiliation(s)
- S Botez
- Service de neurologie, CHUV, Lausanne
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14
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Jeannet PY, Mittaz L, Dunand M, Lobrinus JA, Bonafe L, Kuntzer T. Autosomal dominant nemaline myopathy: A new phenotype unlinked to previously known genetic loci. Neuromuscul Disord 2007; 17:6-12. [PMID: 17157023 DOI: 10.1016/j.nmd.2006.10.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2006] [Revised: 10/03/2006] [Accepted: 10/11/2006] [Indexed: 11/15/2022]
Abstract
We report a large family with a mild form of autosomal dominant nemaline myopathy and a new phenotype. Onset of symptoms was in infancy with hypotonia and motor delay. Weakness involved neck flexors, abdominal and proximal limb muscles. There was no bulbar, respiratory or foot dorsiflexion weakness and no slowness in movement. Patients had remarkably good physical endurance and no limitation in daily activities, but were slow runners since childhood. Nemaline rods were seen in less than 5% of muscle fibres. No linkage to the five known nemaline myopathy genes (alpha-tropomyosin-3, nebulin, alpha-actin, troponin T1 and beta-tropomyosin), to the ryanodine receptor gene (associated with core-rod myopathy) or to the 15q21-23 locus was found.
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Affiliation(s)
- P Y Jeannet
- Neuropediatrics Unit, Department of Pediatrics, Centre Hospitalier Universitaire Vaudois, 1011 Lausanne, Switzerland.
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15
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Dunand M, Gremion G, Jeannet P, Jeanrenaud X, Yaou RB, Bonne G, Kuntzer T. G.P.4.06 A new intermediate phenotype in a Swiss family with mutation in the LMNA gene. Neuromuscul Disord 2006. [DOI: 10.1016/j.nmd.2006.05.114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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16
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Bonnet C, Dunand M, Etienne B, Herblot S, Mathieu P. [Constraint and therapeutic space]. Soins Psychiatr 1993:28-32. [PMID: 8202755] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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17
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Dunand M, Kraehenbuhl JP, Rossier BC, Aubert ML. Purification of PRL receptors from toad kidney: comparisons with rabbit mammary PRL receptors. Am J Physiol 1988; 254:C372-82. [PMID: 3126667 DOI: 10.1152/ajpcell.1988.254.3.c372] [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] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The binding characteristics of the prolactin (PRL) receptors present in toad (Bufo marinus) kidneys were investigated and compared to those of PRL receptors present in rabbit mammary glands. The molecular characteristics of the Triton X-100 solubilized renal and mammary PRL receptors were assessed by gel filtration and by migration analysis on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) after affinity labeling of the binding sites with 125I-human growth hormone. Similar results were obtained for both receptors. Partial purification of the toad PRL receptor could be achieved by affinity chromatography. The molecular weight of this purified receptor could be determined by analysis on SDS-PAGE. With the use of a polyclonal antiserum raised against a purified preparation of rabbit mammary PRL receptor, one or several antigenic epitope(s) could be identified on the core of the toad renal PRL receptor. In conclusion, although the structure and the biological role(s) of PRL have substantially changed during evolution, the receptor for this hormone has retained many of its structural features as could be assessed between an amphibian and a mammalian species on functionally different target tissues.
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Affiliation(s)
- M Dunand
- Department of Pediatrics and Genetics, University of Geneva School of Medicine, Switzerland
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18
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Garcia I, Sordat B, Rauccio-Farinon E, Dunand M, Kraehenbuhl JP, Diggelmann H. Establishment of two rabbit mammary epithelial cell lines with distinct oncogenic potential and differentiated phenotype after microinjection of transforming genes. Mol Cell Biol 1986; 6:1974-82. [PMID: 3023914 PMCID: PMC367736 DOI: 10.1128/mcb.6.6.1974-1982.1986] [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] Open
Abstract
The goal of this work was to establish an assay for transformation of epithelial cells. Two epithelial cell lines were obtained after microinjecting transforming genes into primary rabbit mammary secretory cells. The cell lines were analyzed for their oncogenic potential and for the maintenance of a differentiated phenotype. A fully transformed cell line, which retained epithelial cell organization, was obtained by coinjecting simian virus 40 DNA and the activated human c-Ha-ras gene. The proliferation rate of these cells was high, with a doubling time of 16 h. Their growth was anchorage independent, and they had lost contact inhibition. The cells were tumorigenic in nude mice, but had no metastatic potential. Both microinjected DNAs were efficiently transcribed and translated, in contrast to the casein genes, which were expressed in primary cells but not in the transformed cell line. An immortalized cell line established after injection with simian virus 40 DNA alone was characterized by a moderate rate of proliferation with a doubling time of approximately 30 h. The growth of these cells was contact inhibited and anchorage dependent. The cells were not tumorigenic in nude mice. The viral DNA was expressed during early passages, as shown by the presence of the large T antigen in cell nuclei, but not at later passages. A high number of lactogenic hormone receptors were found associated with the cell surface. Despite the presence of these receptors, no induction of genes coding for milk proteins was observed after addition of prolactin. These data demonstrate that this assay system can be used to assess the immortalizing and transforming potential of candidate oncogenes in epithelial cells.
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Dunand M, Aubert ML, Kraehenbuhl JP, Rossier BC. Specific binding sites for ovine prolactin in three amphibian cell lines. Am J Physiol 1985; 248:C80-7. [PMID: 2981477 DOI: 10.1152/ajpcell.1985.248.1.c80] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Established cell lines (TB-6c and TB-M) obtained by continuous culture of epithelial cells from toad Bufo marinus urinary bladder, which, in culture, maintained a high degree of functional differentiation, exhibited a significant number of high-affinity (KA = 1-2 X 10(10) M-1) binding sites detected both with radioiodinated (125I) ovine prolactin (oPRL) and human growth hormone (hGH). Binding capacity was higher in the case of TB-6c cells (7,573 +/- 581 sites/cell) than with the TB-M cells (1,160 +/- 87). Similarly, binding sites for oPRL were characterized on Xenopus laevis kidney-derived cell line A6. With oPRL used both as tracer and standard, significant cross-reaction was observed with hGH, less with human or rat prolactin (PRL), and none with human chorionic somatomammotropin, bovine growth hormone, and rat luteinizing hormone or follicle-stimulating hormones. B. marinus pituitary extracts completely displaced the binding of 125I-oPRL to toad bladder binding sites. This finding of specific sites for PRL on amphibian bladder and kidney cells confirms that PRL exerts specific biological actions for the control of electrolyte and water metabolism in the amphibians.
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Abstract
In order to examine audience effects when viewing filmed violence, male subjects watched an aggressive or a neutral movie either alone, accompanied by a passive confederate (i.e. mere presence of a co-spectator), or an active one (i.e. reacting to the movie). The subsequent behavioural measures of subjects' aggression were collected via a modified aggression apparatus. The usual instigation effect of filmed violence was found. Furthermore, the type of audience also influenced aggression: subjects accompanied by an active confederate during the violent movie displayed their aggressive behaviour most. These findings stress the importance of the social context when filmed violence is viewed. The results are discussed in terms of social facilitation and disinhibition effects. It is suggested that an active audience may promote a reduction of restraints against aggressing by showing the subject that aggression is permissible.
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