FSH receptor is selectively expressed on the surface of the blood vessels of a wide range of tumors. (Funded by INSERM.).

Abstract. Monoclonal anti-receptor antibodies were used to study the cellular traffic of the hCG/LH receptor by immunoelectron microscopy. The LHR38 antibody was shown to bind to the extraceUular domain of the receptor but not to interfere with hormone binding, adenylate cyclase activation or with the rate of internalization of the receptor. Pig Leydig cells and a permanent L-cell line expressing the LH receptor were used for the study. Incubation with LHR38-gold complexes showed the LH receptors to be randomly distributed over the cell surface including the clathrin coated pits. The LH receptors were internalized via a route including coated pits, coated vesicles and multivesicular bodies to lysosomes. This route is different from that observed for/3-adrenergic, muscarinic, and yeast mating factor receptors and considered previously as possibly general for G-protein-coupled receptors. The use of [~25I]LHR38 allowed precise measurement of the rate of internalization, showing the existence of a constitutive pathway which was increased 11-fold by hormone administration. Double labeling experiments suggested that the hormone (hCG-Au~sm) and the receptor (labeled with LHR38-Ausm) have similar routes of endocytosis, both of them being degraded in lysosomes. Studies of the reappearance of LHR38-Aus~ on the surface of the cells and the use of monensin indicated that only a very small proportion of the receptor molecules were recycled to the cell surface. The distribution and the intracellular pathways of LH receptors are very similar in Leydig cells and transfected L-cells. This opens the possibility of using the latter to study, by in vitro mutagenesis, the molecular mechanisms involved in the cellular traffic of LH receptors. C ELL surface receptors for various ligands differ in their localization and their mechanisms and pathways of internalization. These receptors may be: (a) either specifically included in the coated pits (i.e., LDL-receptors [3,4], transferrin receptors [18][19][20]); (b) expressed only outside the coated pits on the membrane (i.e., B-adrenergic receptors) (37); or (c) randomly exposed on the cell surface, coated pits included (i.e., EGF-receptors) (11,12). Under the effect of the ligand (or sometimes constitutively) (16, 46) the receptor is internalized and may follow one of the four major endocytic pathways which have been described: (a) the ligand-receptor complex dissociates at the endosomal level; the receptor is recycled to the surface whereas the ligand is degraded in lysosomes (i.e., LDL receptor) (7); (b) the ligand-receptor complex is recycled to the cell surface, dissociates and the receptor is reused (i.e., transferrin receptor) (20); (c) the ligand-receptor complex is delivered by transcytosis to the opposite front of polarized cells where the ligand is released intact and the receptor partlally degraded (i.e., IgA receptor) (31); and (d) both partners are transported to lysosomes and degraded (i.e., EGFreceptor) (12).The hCG/LH receptor is involved in the regulation of steroidogenes...

A mouse was immunized with purified rabbit uterine cytosolic progesterone receptor (specific activity: 3 nmol of steroid bound per mg of protein). After fusion of its spleen cells with Sp2-OAg myeloma cells, supernatants of 11 hybrid cultures were found to react in both an immunoenzymatic test and a double-immunoprecipitation test with the progesterone receptor. Clones were obtained from the five hybrid cells that gave the strongest response in both tests. Antibodies from cell culture supernatants and ascitic fluids were characterized. Three are of the IgGl and two of the IgG2a isotype. Their apparent affinity for the progesterone receptor was measured by immunoprecipitation in physiological salt conditions. The equilibrium dissociation constants were between 0.1 and 4 nM. All five monoclonal antibodies crossreacted with the rabbit nuclear receptor, the human cytosolic receptor, and other mammalian (rat, guinea pig) but not avian (chicken) cytosolic progesterone receptors. There was no interaction with the glucocorticoid receptor and corticosteroid binding globulin.The study of steroid hormone receptors has been hampered for many years by difficulties in the purification of these proteins and by the impossibility of using immunological tools for their detection and quantification. Initial progress in this field has been made for the estrogen receptor (1, 2). In the case of the progesterone receptor, preparation of polyclonal antibodies against mammalian receptors (3) and recently against avian receptors (4) has been reported. However for such antigens, which occur in low concentrations and are difficult to purify, the possibility remains of misinterpretations caused by the presence of antibodies directed against proteins contaminating the receptor preparation.To solve this problem we have undertaken the preparation of monoclonal antibodies against the rabbit progesterone receptor. MATERIALS AND METHODSPurification of the Rabbit Uterine Progesterone Receptor. Receptor was purified as described (3). However, to concentrate the receptor and increase the purity a final purification step was added. Receptor eluted from the hydroxyapatite column with 0.2 M sodium phosphate, pH 7.4/30% (vol/vol) glycerol buffer was diluted 1:3.2 in 1 mM sodium phosphate, pH 7.4/30% glycerol buffer. It was applied to a small (0.7-ml) calf thymus DNA-cellulose column. After washing with 10 mM Tris-HCl/1.5 mM EDTA, pH 7.4/30% glycerol buffer (10 ml) and with the same buffer but containing 0.1 M NaCl (10 ml) and finally 5 mM pH 7.4 sodium phosphate buffer (10 ml) the receptor was eluted in 0.8 ml of 5 mM.sodium phosphate/0.5 M NaCl buffer, pH 8.3. The specific activity of the receptor preparation that was used for immunization was 3 nmol of steroid bound per mg of protein. Receptor concentration was 750 pmol/ 0.8 ml.Immunization. A 3-month-old BALB/c mouse received subcutaneous injections of 375 pmol of receptor. The receptor solution was concentrated 2-fold by lyophilization and emulsified with an equal volume (0.2 ml) of complet...

Environmental disorders associated with vitamin D deficiency include musculoskeletal disorders (childhood rickets, osteomalacia, and fractures), and may include extraskeletal disorders (diabetes, cardiovascular disease, risk of falls, and cancer). There is high interindividual variability in the occurrence of both musculoskeletal and extraskeletal disorders. Previous twin and family studies suggested that genetic factors play a significant role in this variability. Little data exist on the possible effects of common genetic variation on vitamin D status; the available studies have been small and only small numbers of variants were examined.The SUNLIGHT consortium (study of underlying genetic determinants of vitamin D and highly related traits) was a multicenter genome-wide association study designed to identify common genetic variants that affect vitamin D concentrations and increase the risk of vitamin D insufficiency. Concentrations of vitamin D were determined in 33,996 individuals of European descent from 15 epidemiologic cohorts. Of these cohorts, 5 were designated as discovery cohorts (n ϭ 16,125), 5 as in-silico replication cohorts (n ϭ 9367), and 5 as de novo replication cohorts (n ϭ 8504). Genome-wide analyses were conducted in all cohorts. Methods used to measure 25-hydroxyvitamin D concentrations varied between cohorts and included radioimmunoassay, chemiluminescent assay, enzyme-linked immunosorbent assay, or mass spectrometry. Concentrations lower than 75 nmol/L or 50 nmol/L were the defined threshold for vitamin D insufficiency. Combined effect estimates from the logistic regression analysis across cohorts were calculated by meta-analysis using a weighted Z-score-based approach. A genotype score was constructed by taking a weighted average of the confirmed variants. GYNECOLOGYVolume 66, Number 2 OBSTETRICAL AND GYNECOLOGICAL SURVEY ABSTRACT A number of epidemiological studies have reported an association between plasma levels of the proinflammatory cytokines, C-reactive protein (CRP), interleukin-6 (IL-6), and the risk of cardiovascular disease and all-cause mortality. Plasma levels of these cytokines also appear to be associated with obesity and insulin resistance; both are elevated in patients with type 2 diabetes and insulin resistance. Approximately 15% to 30% of factors associated with exceptional longevity are genetic. Many of the environmental factors associated with exceptional longevity are potentially modifiable. The association between circulating CRP and IL-6 levels with type 2 diabetes and cardiovascular disease, diseases generally associated with decreased survival, suggests that elevations in the plasma levels of these inflamma- Cardiovascular Endocrinology 93ABSTRACT Short-term risks to children conceived by in vitro fertilization (IVF) include adverse perinatal outcomes and birth defects. Little data are available on long-term risks in IVF children, especially for subtle measures of cognitive development. The few studies that have investigated cognitive development in these children...

؊ and cholera toxin. G s activation provoked a similar effect on LH receptor distribution in MDCK cells, whereas it did not modify the compartmentalization of the TSH receptor. Hormone-specific transcytosis was observed in MDCK cells expressing the gonadotropin (FSH and LH) receptors and was increased after cholera toxin administration.The gonadotropin (LH 1 and FSH) and thyrotropin (TSH) receptors belong to the large family of G-protein-coupled receptors (1-4). They possess the distinctive seven transmembrane spanning domains. However, they form a specific subgroup characterized by the presence of a large extracellular domain constituted by the repetition of leucine-rich motif (5). This ectodomain is responsible for the high affinity hormone binding (6 -9). Gonadotropin and TSH receptors are mainly coupled to G s and thus activate adenylate cyclase. The same receptors are also able to activate phospholipase C at high hormone concentrations. Mutations of the receptors have been described leading either to their constitutive activation (10 -12) or in contrast to a loss of receptor function (13)(14)(15).Little is known about the cellular trafficking of G-proteincoupled receptors in general and of this subgroup of receptors in particular. Ultrastructural immunocytochemistry has been used to analyze the internalization mechanisms of some receptors (16 -18). LH receptor-driven hormone transcytosis was observed through endothelial cells of testicular blood vessels (19). Recently immunocytochemistry using specific monoclonal antibodies demonstrated the basolateral distribution of the TSH receptor in thyroid cells (20) and of the FSH receptor in Sertoli cells (21), whereas the LH receptor was present all over the cell surface of thecal, granulosa, and luteal cells in the ovary and Leydig cells in the testes (22,23).The question was thus raised as to whether these differences in cellular distribution were due to differences in the structure of receptors or simply secondary to the fact that thyroid follicular cells and Sertoli cells are polarized, whereas the LH receptor-expressing cells are not polarized. Another question raised was whether the mechanisms of receptor basolateral delivery were cell-specific or whether the receptors contained specific signals that could direct them to this membrane compartment in any polarized cell. To answer these questions we have established MDCK cell lines that express the FSH, LH, and TSH receptors. Using these models we have analyzed the distribution of the receptors in polarized monolayers. MATERIALS AND METHODSCell Culture-MDCK cells (type II) were seeded and grown on coverslips (Nunc) or filters (0.4-m polycarbonate, tissue culture-treated, Transwell costar) as described previously (24,25).Antireceptor Antibodies-Mouse monoclonal antibodies FSHR323 (21), LHR38 (26),27) recognize an epitope in the extracellular domain of the FSH, LH, and TSH receptors, respectively. Antibody T3-365 has been raised against the intracellular domain of the TSH receptor (20). The rabbit polyclonal TSHR...

Progesterone receptor from rabbit uterine cytosol was purified to a specific activity of -2 nmol of bound hormone per mg of protein. A goat was immunized with this preparation and, after two injections of 0.7-0.8 nmol, yielded antireceptor antibodies. The antiserum reacted with both cytosolic and nuclear rabbit progesterone receptor and also with progesterone receptor from other rabbit tissues (vagina and pituitary). A crossreaction was observed with progesterone receptors from other mammalian, especially human, tissues (cytosolic receptor from rat and guinea pig uterus, cytosolic receptor from human breast cancer, and nuclear receptor from human endometrium). On the contrary, there was no interaction with a nonmammalian receptor (chicken oviduct progesterone receptor). The antibodies did not crossreact with other rabbit steroid receptors (uterine estradiol receptor and liver glucocorticoid receptor) or with nonreceptor progesteronebinding proteins (transcortin from plasma and uteroglobin from uterine fluid).The functional properties and physiological or pathological variations of steroid receptors have been extensively studied (for review, see refs. 1 and 2). However, little is known about their structure and biosynthesis. This is mainly due to difficulties in purification of the receptors and in obtaining antibodies to them. Some preliminary results have been described on the production of antisera against estrogen (3) and glucocorticoid (4) receptors. However, more detailed characterization of antibodies (5, 6) and even production of monoclonal immunoglobulins (7) have been described only for the estrogen receptor. We report here the preparation and some of the properties of antibodies against the progesterone receptor. MATERIALS AND METHODSBuffer. Tris/EDTA buffer (0. 01 M Tris-HCI/1.5 mM EDTA/ 2 mM dithiothreitol, pH 7.4) was used except when stated. Immunoglobulins were kept in 0.01 M sodium phosphate/0. 15 M NaCl, pH 7.4.Steroid. 3H-Labeled R5020 (specific activity, 85 Ci/mmol; 1 Ci=3.7 X 10'°becquerels) was obtained from New England Nuclear.Purification of the Receptor. The method of purification will be reported in detail elsewhere; it will only be summarized here. New Zealand rabbits weighing 1 kg were treated during 15 days with daily subcutaneous injections of 100 ,g of diethylstilbestrol in 0.5 ml of sesame oil. Uterine cytosol was prepared and incubated with 0.1 ,uM 3H-labeled R5020 (specific activity, 2 Ci/mmol). The hormone-receptor complex was precipitated by 10% (wt/vol) Polymin P (Badische Anilin and Soda Fabrik, Ludwigshafen, Federal Republic of Germany), extracted with 0.2 M KCl, and reprecipitated by 33% saturated ammonium sulfate. The pellet was dissolved and chromatographed on DNA-cellulose. After elution with buffer containing 1 M NaCl, the receptor was adsorbed on a column of phenylSepharose (Pharmacia) and eluted with buffer containing 30% glycerol and 40% ethylene glycol. The eluate was applied to a column of hydroxylapatite and finally eluted with 0.2 M sodium phosphate at p...

A method is described to map contiguous epitopes recognized by monoclonal antibodies in the case when the cDNA for a protein has been cloned. The cDNA is inserted into an expression vector allowing its acellular transcription, followed by the translation of the resulting messenger RNA. C-terminally truncated species of the protein are either generated by cutting the cDNA with restriction enzymes or arise spontaneously through stops occurring during translation of the mRNA. If necessary, progressive digestion by Ba131 of the cDNA can be used to produce an array of polypeptides having different C-terminal lengths. Immunoprecipitation then allows determination of the shortest protein recognized by the monoclonal antibody and thus to define its site of action.This method has been applied to the study of a group of selected monoclonal antibodies among the 59 that have been prepared against the rabbit progesterone receptor. Four immunogenic domains were identified lying between amino acids 1-60, 101 -110, 295-325 and 370-396. There were no antibodies directed against the DNA-binding or the steroid-binding regions of the receptor. This is probably due to the high degree of amino acid sequence conservation in these domains, observed when comparing receptors from different species. The antibodies cross-reacting with highest affinity for the human receptor interact with the first immunogenic domain (amino acids 1 -60).The 79-kDa form ('subunit A') of the receptor was shown to lack the two more N-terminally localized immunogenic domains (amino acids 1-60 and 101 -110). The 65-kDa form lacked, in addition, the domain localized between amino acids 295 and 325. These two forms of the receptor thus correspond to deletions of the N-terminal part of the protein.The precise mapping of epitopes recognized by monoclonal antibodies is important for the definition of immunogenic [l] In most cases in which monoclonal antibodies are available for a protein the corresponding cDNA has been cloned or can easily be cloned. We here describe a technique involving acellular transcription/translation of the cloned cDNA, in which use is made of spontaneously occurring or provoked premature terminations of translation. Immunoprecipitation of the C-terminally truncated proteins allows, in a few rapid experiments, the precise mapping of corresponding epitopes. This method has been applied using a series of monoclonal antibodies raised against the rabbit progesterone receptor. It has led to the definition of the immunogenic sites and to the cartography of the various forms of this regulatory protein. Special emphasis has been put on the study of the so-called 'A form' of the receptor (molecular mass 79 kDa) which is considered by some to be a distinct physiological entity in chick [15] and human [16]. However, our studies performed in the rabbit suggest that it arises by artefactural proteolysis 1171 of the native receptor ('B form', apparent molecular mass in SDS/polyacrylamide gels: 110 kDa, molecular mass deduced from sequence: 98554 Da 1181)....

Previous studies have shown a heterogeneous expression of LH receptors in various structures of the porcine ovary. Specially striking was the existence in the preovulatory follicle of inner layers of theca interna cells devoid of LH receptor and the confinement in the corpus luteum of the LH receptor to the external cellular layers. In the present study, we have compared the steroidogenic capabilities of LH receptor-positive and -negative cells using immunocytochemistry for side-chain cleavage P450, 3 beta-hydroxysteroid-dehydrogenase, 17 alpha-hydroxylase P450 and aromatase P450. We have also examined, using the same methods, the evolution of the various cell types after ovulation and during the development of the corpus luteum. In preovulatory follicles the inner layers of theca cells which were not labelled with anti-LH receptor antibodies appeared to express the steroidogenic enzymes in a way similar to that of the outer LH receptor-positive cell layers. Ovulation per se did not change the distribution of LH receptors (present in the outer luteal cells and in the granulosa) or of steroidogenic enzymes. However, 48 h after follicular rupture there as a marked decrease in overall labelling with anti-LH receptor antibody, and especially a disappearance of immunostaining in the luteal cells of granulosa origin. In the mid-luteal phase (6 days after ovulation), the receptor content seemed to increase in the peripheral luteal cells derived from the theca but the receptor did not reappear in the granulosa-derived luteal cells. Thus the down-regulation of LH receptor appeared to be reversible in the external thecal layers but irreversible in the granulosa cells. Furthermore, the distribution of the various steroidogenic enzymes in the corpora lutea delineated granulosa-derived from theca-derived cells and showed that only the external layers of the latter expressed the LH receptor. These results showed the existence in the preovulatory follicle of two theca interna regions expressing the same steroidogenic enzymes but possibly submitted to a different hormonal control. Furthermore, the cells derived from these two regions as well as the cells of granulosa origin showed a distinct pattern of variation of LH receptivity during the development of the corpus luteum. During these studies we also observed that, in the interstitial tissue, only a minority of cells which derived from remnants of atretic follicles expressed both the LH receptor and the steroidogenic enzymes.