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1.
Bull Acad Natl Med ; 194(6): 1033-44, 2010 Jun.
Artigo em Francês | MEDLINE | ID: mdl-21513136

RESUMO

Medical prevention of recidivism by sexual delinquents is controversial, yet the abundant scientific literature on this issue is often ignored. Many publications show how difficult it is to estimate the danger represented by convicted sexual criminals but underline the value of so-called actuarial approaches. Hormonal treatments and psychotherapy have limited effectiveness in the medium and long term. As a result, anti-recidivism policies cannot currently be based mainly on medical prevention.


Assuntos
Delitos Sexuais/prevenção & controle , Antagonistas de Androgênios/uso terapêutico , Hormônio Liberador de Gonadotropina/agonistas , Humanos , Psicoterapia , Prevenção Secundária
2.
Endocr Rev ; 23(4): 401-30, 2002 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12202458

RESUMO

Glycodelin is a glycoprotein that belongs to the lipocalin superfamily. Depending on glycosylation, glycodelin appears in various isoforms. In the uterus, glycodelin-A is the major progesterone-regulated glycoprotein secreted into uterine luminal cavity by secretory/decidualized endometrial glands. The other tissues expressing glycodelin include fallopian tubes, ovary, breast, seminal vesicle, bone marrow, and eccrine glands. Glycodelin-A potently and dose-dependently inhibits human sperm-egg binding, whereas differently glycosylated glycodelin-S from seminal plasma has no such effect. Absence of contraceptive glycodelin-A in the uterus during periovulatory midcycle is consistent with an open "fertile window." Glycodelin induced by local or systemic administration of progestogens may potentially reduce the fertilizing capacity of sperm in any phase of the menstrual cycle. Glycodelin also has immunosuppressive activity. Its high concentration at the fetomaternal interface may contribute to protection of the embryonic semiallograft. Besides being an epithelial differentiation marker, glycodelin appears to play a role in glandular morphogenesis, as transfection of glycodelin cDNA into a glycodelin-negative breast cancer cells resulted in formation of gland-like structures, restricted proliferation, and induction of other epithelial markers. These various properties, as well as the chemistry, biology, and clinical aspects of glycodelin, continue to be areas of active investigation reviewed in this communication.


Assuntos
Genitália/fisiologia , Glicoproteínas/fisiologia , Proteínas da Gravidez/fisiologia , Reprodução/fisiologia , Diferenciação Celular/fisiologia , Genitália/citologia , Glicodelina , Humanos
3.
Mol Endocrinol ; 20(9): 2122-40, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16645042

RESUMO

Modulators of cofactor recruitment by nuclear receptors are expected to play an important role in the coordination of hormone-induced transactivation processes. To identify such factors interacting with the N-terminal domain (NTD) of the progesterone receptor (PR), we used this domain as bait in the yeast Sos-Ras two-hybrid system. cDNAs encoding the C-terminal MYST (MOZ-Ybf2/Sas3-Sas2-Tip60 acetyltransferases) domain of HBO1 [histone acetyltransferase binding to the origin recognition complex (ORC) 1 subunit], a member of the MYST acetylase family, were thus selected from a human testis cDNA library. In transiently transfected CV1 cells, the wild-type HBO1 [611 amino acids (aa)] enhanced transcription mediated by steroid receptors, notably PR, mineralocorticoid receptor, and glucocorticoid receptor, and strongly induced PR and estrogen receptor coactivation by steroid receptor coactivator 1a (SRC-1a). As assessed by two-hybrid and glutathione-S-transferase pull-down assays, the HBO1 MYST acetylase domain (aa 340-611) interacts mainly with the NTD, and also contacts the DNA-binding domain and the hinge domains of hormone-bound PR. The HBO1 N-terminal region (aa 1-340) associates additionally with PR ligand-binding domain (LBD). HBO1 was found also to interact through its NTD with SRC-1a in the absence of steroid receptor. The latter coassociation enhanced specifically activation function 2 activation function encompassed in the LBD. Conversely, the MYST acetylase domain specifically enhanced SRC-1 coupling with PR NTD, through a hormone-dependent mechanism. In human embryonic kidney 293 cells expressing human PRA or PRB, HBO1 raised selectively an SRC-1-dependent response of PRB but failed to regulate PRA activity. We show that HBO1 acts through modification of an LBD-controlled structure present in the N terminus of PRB leading to the modulation of SRC-1 functional coupling with activation function 3-mediated transcription. Importantly, real-time RT-PCR analysis also revealed that HBO1 enhanced SRC-1 coactivation of PR-dependent transcription of human endogenous genes such as alpha-6 integrin and 11beta-hydroxydehydrogenase 2 but not that of amphiregulin. Immunofluorescence and confocal microscopy of human embryonic kidney-PRB cells demonstrated that the hormone induces the colocalization of HBO1 with PR-SRC-1 complex into nuclear speckles characteristic of PR-mediated chromatin remodeling. Our results suggest that HBO1 might play an important physiological role in human PR signaling.


Assuntos
Histona Acetiltransferases/metabolismo , Complexo de Reconhecimento de Origem/metabolismo , Receptores de Progesterona/metabolismo , Transcrição Gênica/genética , Ativação Transcricional/genética , Animais , Linhagem Celular , Chlorocebus aethiops , Hormônios/metabolismo , Humanos , Ligantes , Coativador 1 de Receptor Nuclear , Complexo de Reconhecimento de Origem/genética , Ligação Proteica , Subunidades Proteicas/genética , Subunidades Proteicas/metabolismo , Receptores de Progesterona/genética , Receptores de Esteroides/metabolismo , Transdução de Sinais , Fatores de Transcrição
4.
Mol Endocrinol ; 19(8): 2086-98, 2005 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-15878956

RESUMO

Several molecular models of glycoprotein hormone receptor activation have been proposed. It has been suggested that ligand binding to the ectodomain (ECD) leads to major changes in intramolecular interactions between the ECD and the transmembrane domain. We studied these intramolecular modifications by generating a recombinant LH/CG receptor (LHR) bearing an intramolecular cleavage site. We did this by inserting a furin site at position 316 in the hinge region of the ECD (LHR_Fur316). Affinity for human chorionic gonadotropin (hCG) and cAMP production upon hCG stimulation was identical to those of wild-type LHR. Western blot analysis showed that the LHR_Fur316 receptor was cleaved into two subunits linked by disulfide bridges. Chemical shedding of the ECD from the transmembrane domain did not increase basal adenylate cyclase activity, indicating that the first 294 residues did not act as an inverse agonist. The truncated LHR_316 was still activated by hCG but with an EC50 higher than that for the wild-type receptor. Zero length cross-linking was used to study intramolecular interactions between the two domains of LHR_Fur316. Cross-linking efficiency was similar for the basal and activated states, which indicated that the two domains interacted closely in the basal state, and this tight interaction persisted during activation. Our data suggest that activation of the LHR results from subtle modifications of intramolecular interactions between the two domains and low-affinity binding of hCG to the extracellular loops or residues preceding the first transmembrane segment.


Assuntos
Reagentes de Ligações Cruzadas/farmacologia , Receptores do LH/química , Ácido Aspártico/química , Sítios de Ligação , Western Blotting , Membrana Celular/metabolismo , Separação Celular , AMP Cíclico/metabolismo , Dissulfetos/química , Relação Dose-Resposta a Droga , Citometria de Fluxo , Furina/química , Ácido Glutâmico/química , Humanos , Immunoblotting , Lisina/química , Modelos Biológicos , Ligação Proteica , Estrutura Terciária de Proteína , Receptores do LH/metabolismo , Proteínas Recombinantes/química , Fatores de Tempo , Transfecção
5.
J Steroid Biochem Mol Biol ; 94(4): 289-302, 2005 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15857748

RESUMO

In the present study, we analyzed human follicle-stimulating hormone (FSH)-induced cell proliferation and transactivation of estrogen-sensitive reporter genes-in L cells stably expressing the human FSH receptor [L-(hFSHR(+)) cells]. In order to dissect the signaling pathways involved in this process, L-(hFSHR(+)) cells were transiently transfected with either the 3X-ERE-TAT-Luc or the ERE-VitA2-TK-CAT reporter genes and treated with FSH or PKA activators (cholera toxin, forskolin and 8-Br-cAMP) in the presence or absence of various kinase inhibitors. We found that FSH and all PKA activators, specifically induced transactivation of both reporter genes. Transactivation of estrogen-sensitive genes by FSH or PKA activators were blocked (approximately 90%) by H89 (PKA inhibitor) and LY294002 but not by Wortmannin (PI3-K inhibitors), 4-OH-tamoxifen, ICI182,780 or SB203580 (p38 MAPK inhibitor); PD98059 (ERK1/2 inhibitor) partially (approximately 30%) blocked the FSH-mediated effect. The combination of FSH and estradiol resulted in a synergistic effect on transactivation as well as on cell proliferation, and this enhancement was attenuated by antiestrogens. We additionally analyzed the participation of the coactivators SRC-1 and cAMP response element binding protein (CREB)-binding protein (CBP) in FSH-evoked estrogen receptor (ER)-dependent transactivation; we found that CBP but not SRC-1 potentiated FSH-induced transcriptional activation of both ER-sensitive reporters, being this effect stronger on the ERE-VitA2-TK-CAT than on the 3X-ERE-TAT-Luc reporter. Thus, in L-(hFSHR(+)) cells FSH induces transcriptional activation of estrogen-sensitive genes through an A-kinase-triggered signaling pathway, using also to a lesser extent the ERK1/2 and p38 pathways. PI3-K is not apparently involved in this FSH-mediated process since LY294002, but not Wortmannin, specifically binds ERs and completely blocks estrogen action. Presumably, CBP cooperates with the ER on genes that contain estrogen responsive elements through mechanisms involving the participation of other proteins and/or basal transcription factors (e.g. CREB), which in turn mediate the transcriptional response of estrogen-sensitive reporter genes to FSH stimulation.


Assuntos
Estradiol/farmacologia , Hormônio Foliculoestimulante/farmacologia , Genes Reporter/efeitos dos fármacos , Células L/efeitos dos fármacos , Ativação Transcricional/efeitos dos fármacos , Animais , Ligação Competitiva , Proteína de Ligação a CREB , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Chlorocebus aethiops , Sinergismo Farmacológico , Humanos , Camundongos , Proteínas Nucleares/farmacologia , Regiões Promotoras Genéticas , Receptores de Estrogênio/metabolismo , Receptores do FSH/metabolismo , Transativadores/farmacologia
6.
Mol Endocrinol ; 16(5): 912-23, 2002 May.
Artigo em Inglês | MEDLINE | ID: mdl-11981027

RESUMO

Using immunocytochemistry, we have observed that the TSH receptor (TSHR) is concentrated at the leading edge of lamellipodia in both cultured human thyroid cells and in various transfected cells. This segregation of the receptor is due to its interaction with extracellular matrix (ECM) and specially with fibronectin. The TSHR, which interacts with the ECM, is known to undergo cleavage by a matrix metalloprotease. The homologous LH receptor, which does not interact with ECM, is not cleaved. The attachment to the ECM modifies the functional properties of the receptor: it increases adenylate cyclase stimulation by hormone, whereas PLC stimulation is not modified. Furthermore, the constitutive activity of the TSHR is only observed in attached cells, suggesting that it is dependent on TSHR interaction with the ECM. Thus, aside from its classical properties of hormone binding and signalization through G proteins, the TSHR is also involved in cell-matrix interactions, which modulate its functional properties.


Assuntos
Matriz Extracelular/metabolismo , Receptores da Tireotropina/fisiologia , Tireotropina/farmacologia , Adenilil Ciclases/metabolismo , Animais , Linhagem Celular , Fibronectinas/metabolismo , Imunofluorescência , Expressão Gênica , Humanos , Metaloproteinases da Matriz/metabolismo , Camundongos , Microscopia Confocal , Microscopia de Fluorescência , Receptores do LH/metabolismo , Receptores da Tireotropina/análise , Receptores da Tireotropina/genética , Glândula Tireoide/ultraestrutura , Transfecção , Fosfolipases Tipo C/metabolismo
7.
J Clin Endocrinol Metab ; 88(4): 1873-9, 2003 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-12679486

RESUMO

Mutations of the GnRH receptor have been recognized as a cause of familial gonadotropin deficiency. We here identify and functionally characterize a novel human GnRH receptor variant bearing an Ala(171)Thr substitution located at transmembrane helix 4 (TMH4). The affected kindred displays severe hypogonadotropic hypogonadism. After in vitro expression in human embryonic kidney 293T cells, the Ala(171)Thr mutant GnRH receptor exhibited a lack of phospholipase C activity in signal transduction. Specific receptor binding of (125)I-labeled GnRH ligand was undetectable in Ala(171)Thr GnRH receptor-transfected cells. Molecular modeling and dynamic simulation of the Ala(171)Thr GnRH receptor suggests the introduction of a stable hydrogen bond between residue Thr(171) and Tyr(119) side-chains at a distance of 2 A. Although spatially distant from the GnRH ligand-binding site, this hydrogen bond impedes conformational mobility of the TMH3 and TMH4 domains required for sequential ligand binding and receptor activation, thus stabilizing the GnRH receptor in its inactive conformation. Receptor structure modeling and functional data provide a comprehensive molecular view of how mutation Ala(171)Thr causes a complete loss of GnRH receptor function.


Assuntos
Alanina , Hipogonadismo/genética , Mutação , Conformação Proteica , Receptores LHRH/química , Receptores LHRH/genética , Treonina , Adulto , Sítios de Ligação , Linhagem Celular , Embrião de Mamíferos , Expressão Gênica , Humanos , Ligação de Hidrogênio , Rim , Masculino , Modelos Moleculares , Linhagem , Receptores LHRH/fisiologia , Transdução de Sinais , Relação Estrutura-Atividade , Fosfolipases Tipo C/metabolismo
8.
J Clin Endocrinol Metab ; 87(5): 2266-76, 2002 May.
Artigo em Inglês | MEDLINE | ID: mdl-11994374

RESUMO

The regulatory mechanisms of oocyte maturation remain poorly understood. Although gonadotropins play a major role in these processes, they have generally been considered to act on somatic supportive cells, but not directly on germ cells. We have raised high affinity monoclonal antibodies against LH and FSH receptors. When using the latter to study receptor distribution in human and pig ovaries we have observed the presence of FSH (but not LH) receptors in the oocytes. FSH receptors appeared in the oocytes of primary follicles during follicular development and persisted up to the preovulatory stage. In denuded human preovulatory oocytes, FSH receptor mRNA was detected at a concentration per cell exceeding by about 20-fold that present in granulosa cells. Saturable binding of [(125)I]FSH to the membrane of oocytes was demonstrated by autoradiography. When incubated with FSH, denuded oocytes responded by a mobilization of Ca(2+). These observations concur to demonstrate the presence of functional FSH receptors in oocytes and raise the possibility of direct control of oocyte development by FSH.


Assuntos
Atresia Folicular/metabolismo , Oócitos/metabolismo , Receptores do FSH/metabolismo , Adulto , Animais , Autorradiografia , Transporte Biológico/efeitos dos fármacos , Cálcio/metabolismo , Feminino , Hormônio Foliculoestimulante/metabolismo , Humanos , Imuno-Histoquímica/métodos , Folículo Ovariano/citologia , Folículo Ovariano/fisiologia , RNA Mensageiro/metabolismo , Receptores do FSH/genética , Coloração e Rotulagem , Suínos
9.
Am J Clin Pathol ; 117(2): 210-6, 2002 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11863217

RESUMO

In giant cell tumors of bone (GCTBs), the mesenchymal stromal cells are the neoplastic cells and induce recruitment and formation of osteoclasts (OCs). Studies on recently discovered members of the tumor necrosis factor receptor-ligand family have demonstrated a crucial role of RANKL (receptor activator of nuclear factor kappa B [RANK] ligand) expressed by osteoblast/stromal cells and of its receptor RANK expressed by OCs during OC differentiation and activation. OCs typically are present in large numbers in GCTBs, suggesting that these tumors may contain cells expressing factors that stimulate OC precursor recruitment and differentiation. We used immunohistochemical analysis to study RANKL and RANK expression in 5 GCTBs. Multinucleated cells and some mononuclear cells showed strong positive staining with anti-RANK antibodies; RANKL was present in a subset of mononuclear cells that did not express the hematopoietic lineage cell marker CD45, a feature that identified them as mesenchymal tumor cells. Our results suggest that RANKL expression may have a role in the pathogenesis of GCTBs and in the formation of the large OC population present in these tumors.


Assuntos
Proteínas de Transporte/biossíntese , Tumor de Células Gigantes do Osso/metabolismo , Tumor de Células Gigantes do Osso/patologia , Glicoproteínas/biossíntese , Glicoproteínas de Membrana/biossíntese , Receptores Citoplasmáticos e Nucleares/biossíntese , Animais , Especificidade de Anticorpos , Células COS , Proteínas de Transporte/análise , Proteínas de Transporte/genética , Contagem de Células , DNA Complementar/metabolismo , Expressão Gênica , Glicoproteínas/análise , Glicoproteínas/genética , Humanos , Imuno-Histoquímica , Antígenos Comuns de Leucócito/análise , Antígenos Comuns de Leucócito/biossíntese , Leucócitos Mononucleares/metabolismo , Leucócitos Mononucleares/patologia , Glicoproteínas de Membrana/análise , Glicoproteínas de Membrana/genética , Mesoderma/metabolismo , Mesoderma/patologia , Osteoblastos/metabolismo , Osteoblastos/patologia , Osteoclastos/metabolismo , Osteoclastos/patologia , Osteoprotegerina , Ligante RANK , Receptor Ativador de Fator Nuclear kappa-B , Receptores Citoplasmáticos e Nucleares/análise , Receptores Citoplasmáticos e Nucleares/genética , Receptores do Fator de Necrose Tumoral , Transfecção
10.
Bull Acad Natl Med ; 187(4): 671-80; discussion 680-2, 2003.
Artigo em Francês | MEDLINE | ID: mdl-14556475

RESUMO

Cloning of the TSH receptor has led to marked progress in the understanding of the pathogenesis of hyperthyroidism. Genetic studies in familial cases of Graves disease have allowed to dismiss the TSH receptor as a candidate gene. Loci harbouring genes probably involved in the occurrence of Graves' disease have been described. Purification of native TSH receptor has allowed to study directly and to characterize the autoantibodies directed against this antigen. In cases of non immune hyperthyroidism the implication of activating mutations of the TSH receptor and of the a subunit of Gs has been described.


Assuntos
Hipertireoidismo/fisiopatologia , Animais , Especificidade de Anticorpos , Autoanticorpos/imunologia , Doenças Autoimunes/imunologia , Subunidades alfa Gs de Proteínas de Ligação ao GTP/genética , Doença de Graves/genética , Doença de Graves/imunologia , Humanos , Hipertireoidismo/genética , Camundongos , Mutação , Receptores da Tireotropina/genética , Receptores da Tireotropina/imunologia
11.
Cancer ; 97(7): 1810-6, 2003 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-12655539

RESUMO

BACKGROUND: It has been established that pregnancy protects against breast carcinoma, and animal models have shown that human chorionic gonadotropin (hCG) mimics this effect by inhibiting the initiation and progression of experimental breast carcinoma. Luteinizing hormone (LH)/hCG receptors (LHR) have been characterized in several human breast carcinoma cell lines and in a limited number of breast carcinoma biopsy specimens. These observations led to the suggestion that hCG may be used as a means of prevention and possibly treatment in patients with breast carcinoma. METHODS: The authors used immunocytochemistry to analyze tumors from 160 patients who were followed for a median of 2539 days. Using a cut-off value of 18% immunolabeled cells in each tumor, 72% of tumors were identified as LHR positive. The LHR-positive tumors were found more frequently in premenopausal women, who had tumors with greater cell differentiation and positive estrogen receptor alpha status. Infiltrating lobular carcinomas were positive for LHR more frequently compared with infiltrating ductal carcinomas. There was no correlation between LHR status and lymph node invasion, tumor size, or progesterone receptor status. RESULTS: Patients with LHR-positive tumors had a longer metastasis free survival, although the statistical significance was slight (P = 0.07), most likely due to the limited number of events in the patients studied. Conversely, there was no difference between patients with LHR-positive or LHR-negative tumors in the local recurrence free interval. CONCLUSIONS: LHR status seems to be related in part to the degree of differentiation in breast tumors, confirming experimental evidence of the effect of hCG on mammary tissue. The presence of LHR is a tumor characteristic that largely is independent of other clinical and pathologic tumor features. It may be of interest in the future to correlate the presence of LHR with a possible therapeutic response in individual patients to hCG.


Assuntos
Neoplasias da Mama/metabolismo , Carcinoma/metabolismo , Receptores do LH/metabolismo , Feminino , Humanos , Pessoa de Meia-Idade , Metástase Neoplásica , Recidiva Local de Neoplasia , Prognóstico , Resultado do Tratamento
12.
J Biol Chem ; 278(14): 12335-43, 2003 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-12529333

RESUMO

SUMO-1 (small ubiquitin-like modifier) conjugation regulates the subcellular localization, stability, and activity of a variety of proteins. We show here that SUMO-1 overexpression markedly enhances progesterone receptor (PR)-mediated gene transcription. PR undergoes a sumoylation at lysine 388 located in its N-terminal domain. However, sumoylation of the receptor is not responsible for enhanced transcription because substitution of its target lysine did not abolish the effect of SUMO-1 and even converted the receptor into a slightly more active transactivator. Furthermore estrogen receptor alpha (ERalpha)-driven transcription is also enhanced by SUMO-1 overexpression contrasting with the absence of sumoylation of this receptor. We thus analyzed SUMO-1 conjugation to the steroid receptor coactivator SRC-1. We showed that this protein contains two major sites of conjugation at Lys-732 and Lys-774. Sumoylation was shown to increase PR-SRC-1 interaction and to prolong SRC-1 retention in the nucleus. It did not prevent SRC-1 ubiquitinylation and did not exert a clear effect on the stability of the protein. Overexpression of SUMO-1 enhanced PR-mediated gene transcription even in the presence of non-sumoylated mutants of SRC-1. This observation suggests that among the many protein partners involved in steroid hormone-mediated gene regulation several are probably targets of SUMO-1 modification.


Assuntos
Receptores de Progesterona/metabolismo , Proteína SUMO-1/metabolismo , Fatores de Transcrição/metabolismo , Sequência de Aminoácidos , Animais , Células COS , Núcleo Celular/metabolismo , Sequência Consenso , Citoplasma/metabolismo , Histona Acetiltransferases , Humanos , Mutagênese , Coativador 1 de Receptor Nuclear , Estrutura Terciária de Proteína , Transporte Proteico/fisiologia , Receptores de Progesterona/genética , Fatores de Transcrição/química , Ativação Transcricional/fisiologia
13.
Proc Natl Acad Sci U S A ; 100(19): 10972-6, 2003 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-12944565

RESUMO

Hypogonadotropic hypogonadism is defined as a deficiency of the pituitary secretion of follicle-stimulating hormone and luteinizing hormone, which results in the impairment of pubertal maturation and of reproductive function. In the absence of pituitary or hypothalamic anatomical lesions and of anosmia (Kallmann syndrome), hypogonadotropic hypogonadism is referred to as isolated hypogonadotropic hypogonadism (IHH). A limited number of IHH cases are due to loss-of-function mutations of the gonadotropin-releasing hormone receptor. To identify additional gene defects leading to IHH, a large consanguineous family with five affected siblings and with a normal gonadotropin-releasing hormone receptor coding sequence was studied. Homozygosity whole-genome mapping allowed the localization of a new locus within the short arm of chromosome 19 (19p13). Sequencing of several genes localized within this region showed that all affected siblings of the family carried a homozygous deletion of 155 nucleotides in the GPR54 gene. This deletion encompassed the splicing acceptor site of intron 4-exon 5 junction and part of exon 5. The deletion was absent or present on only one allele in unaffected family members. GPR54 has been initially identified as an orphan G protein-coupled receptor with 40% homology to galanin receptors. Recently, a 54-aa peptide derived from the KiSS1 protein was identified as a ligand of GPR54. The present study shows that loss of function of GPR54 is a cause of IHH, and it identifies GPR54 and possibly KiSS1 protein-derived peptide as playing a major and previously unsuspected role in the physiology of the gonadotropic axis.


Assuntos
Hipogonadismo/genética , Receptores de Neuropeptídeos/genética , Sequência de Bases , Consanguinidade , Primers do DNA , Feminino , Genótipo , Humanos , Hipogonadismo/fisiopatologia , Masculino , Linhagem , Receptores Acoplados a Proteínas G , Receptores de Kisspeptina-1 , Receptores de Neuropeptídeos/fisiologia
14.
Br J Haematol ; 117(1): 86-92, 2002 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11918537

RESUMO

The new members of the tumour necrosis factor (TNF) receptor-ligand family, receptor activator of nuclear factor-kappaB ligand (RANKL) and its receptor RANK, play a crucial role in osteoclast differentiation and activation. An increased expression of RANKL and/or RANK may be involved in the excessive bone resorption observed in multiple myeloma (MM). We used immunohistochemistry to study RANK and RANKL expression in bone marrow (BM) biopsies obtained at diagnosis in 15 MM patients, six patients with monoclonal gammopathy of undetermined significance (MGUS) and 10 normal BM biopsies. Plasma cells were not labelled with anti-RANKL or anti-RANK antibodies. In all biopsies, RANKL was expressed in endosteal bone surface, around vessels and in cells characterized by cytoplasmic expansions. These last cells did not express CD45 and were vimentin positive, corresponding to bone marrow stromal cells. Numerous stromal cells expressed RANKL in MM and MGUS specimens, with a greater expression in MM than in MGUS. Very few cells were stained with anti-RANKL in normal BM specimens. With the anti-RANK antibody, small mononuclear cells in the bone microenvironment were positive and were identified as erythroblast cells. In conclusion, we showed that RANKL was expressed in reticular stromal cells, with a greater intensity in myeloma specimens. These results suggest that RANKL overexpressed by bone marrow stromal cells may contribute to the high rate of bone resorption observed in MM.


Assuntos
Células da Medula Óssea/química , Proteínas de Transporte/análise , Glicoproteínas/análise , Glicoproteínas de Membrana/análise , Mieloma Múltiplo/metabolismo , Receptores Citoplasmáticos e Nucleares/análise , Estudos de Casos e Controles , Humanos , Imuno-Histoquímica , Osteoprotegerina , Paraproteinemias/metabolismo , Ligante RANK , Receptor Ativador de Fator Nuclear kappa-B , Receptores do Fator de Necrose Tumoral , Células Estromais/química
15.
Gastroenterology ; 126(1): 308-17, 2004 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-14699509

RESUMO

BACKGROUND AND AIMS: The molecular mechanism of hereditary persistence of alpha-fetoprotein (HPAFP) has been previously described in a large Scottish family, consisting of a -119G>A substitution in the distal hepatocyte nuclear factor 1 (HNF-1) binding site of the alpha-fetoprotein (AFP) gene promoter. We report here the molecular mechanisms of HPAFP in 2 new unrelated families. METHODS: Family 1 was of Bengali origin, and family 2 was Italian. Four of 5 subjects (family 1) and 3 of 9 (family 2) showed HPAFP. The AFP gene promoter was studied in all available family members. RESULTS: All subjects with high AFP levels had mutated promoter sequences. Family 1 showed the reported -119G>A substitution. Family 2 showed -55C>A and -65C>T substitutions in the proximal putative HNF-1 binding region of the promoter. The -55C>A mutation increased the similarity of the proximal HNF-1 binding region to a consensus binding region. Gel shift assays confirmed its increased affinity toward HNF-1, and transfection experiments revealed an increased level of gene transcription. The -65C>T substitution theoretically created a CCAAT box. However, gel shift and transfection experiments failed to show any biological effect of this substitution that is associated with the -55C>A mutation. CONCLUSIONS: Two different mutations localized in either HNF-1 binding sites of the AFP gene promoter may result in HPAFP. This highlights the importance of HNF-1 in AFP gene expression. Unexplained persistent AFP should lead to family study and/or AFP gene promoter sequencing to avoid inappropriate explorations and treatment decisions.


Assuntos
Proteínas de Ligação a DNA , Mutação/fisiologia , Proteínas Nucleares , Fatores de Transcrição/metabolismo , alfa-Fetoproteínas/genética , alfa-Fetoproteínas/metabolismo , Sequência de Bases/genética , Sítios de Ligação/genética , Fator 1 Nuclear de Hepatócito , Fator 1-alfa Nuclear de Hepatócito , Fator 1-beta Nuclear de Hepatócito , Humanos , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Linhagem , Regiões Promotoras Genéticas/genética , Regiões Promotoras Genéticas/fisiologia
16.
J Biol Chem ; 278(34): 32195-203, 2003 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-12791702

RESUMO

Steroid hormone receptors are ligand-stimulated transcription factors that modulate gene transcription by recruiting coregulators to gene promoters. Subcellular localization and dynamic movements of transcription factors have been shown to be one of the major means of regulating their transcriptional activity. In the present report we describe the subcellular localization and the dynamics of intracellular trafficking of steroid receptor coactivator 1 (SRC-1). After its synthesis in the cytoplasm, SRC-1 is imported into the nucleus, where it activates transcription and is subsequently exported back to the cytoplasm. In both the nucleus and cytoplasm, SRC-1 is localized in speckles. The characterization of SRC-1 nuclear localization sequence reveals that it is a classic bipartite signal localized in the N-terminal region of the protein, between amino acids 18 and 36. This sequence is highly conserved within the other members of the p160 family. Additionally, SRC-1 nuclear export is inhibited by leptomycin B. The region involved in its nuclear export is localized between amino acids 990 and 1038. It is an unusually large domain differing from the classic leucine-rich NES sequences. Thus SRC-1 nuclear export involves either an alternate type of NES or is dependent on the interaction of SRC-1 with a protein, which is exported through the crm1/exportin pathway. Overall, the intracellular trafficking of SRC-1 might be a mechanism to regulate the termination of hormone action, the interaction with other signaling pathways in the cytoplasm and its degradation.


Assuntos
Núcleo Celular/metabolismo , Citoplasma/metabolismo , Frações Subcelulares/metabolismo , Fatores de Transcrição/metabolismo , Sequência de Aminoácidos , Animais , Sequência de Bases , Ciclo Celular , Linhagem Celular , Cricetinae , Primers do DNA , Histona Acetiltransferases , Humanos , Microscopia Confocal , Dados de Sequência Molecular , Coativador 1 de Receptor Nuclear , Transporte Proteico , Homologia de Sequência de Aminoácidos , Fatores de Transcrição/química
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