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1.
Physiol Genomics ; 52(4): 191-199, 2020 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-32089075

RESUMO

Aortic valve sclerosis is a highly prevalent, poorly characterized asymptomatic manifestation of calcific aortic valve disease and may represent a therapeutic target for disease mitigation. Human aortic valve cusps and blood were obtained from 333 patients undergoing cardiac surgery (n = 236 for severe aortic stenosis, n = 35 for asymptomatic aortic valve sclerosis, n = 62 for no valvular disease), and a multiplex assay was used to evaluate protein expression across the spectrum of calcific aortic valve disease. A subset of six valvular tissue samples (n = 3 for asymptomatic aortic valve sclerosis, n = 3 for severe aortic stenosis) was used to create RNA sequencing profiles, which were subsequently organized into clinically relevant gene modules. RNA sequencing identified 182 protein-encoding, differentially expressed genes in aortic valve sclerosis vs. aortic stenosis; 85% and 89% of expressed genes overlapped in aortic stenosis and aortic valve sclerosis, respectively, which decreased to 55% and 84% when we targeted highly expressed genes. Bioinformatic analyses identified six differentially expressed genes encoding key extracellular matrix regulators: TBHS2, SPARC, COL1A2, COL1A1, SPP1, and CTGF. Differential expression of key circulating biomarkers of extracellular matrix reorganization was observed in control vs. aortic valve sclerosis (osteopontin), control vs. aortic stenosis (osteoprotegerin), and aortic valve sclerosis vs. aortic stenosis groups (MMP-2), which corresponded to valvular mRNA expression. We demonstrate distinct mRNA and protein expression underlying aortic valve sclerosis and aortic stenosis. We anticipate that extracellular matrix regulators can serve as circulating biomarkers of early calcific aortic valve disease and as novel targets for early disease mitigation, pending prospective clinical investigations.


Assuntos
Estenose da Valva Aórtica/sangue , Estenose da Valva Aórtica/genética , Valva Aórtica/metabolismo , Valva Aórtica/patologia , Calcinose/sangue , Calcinose/genética , Ácidos Nucleicos Livres/metabolismo , Osteopontina/metabolismo , Osteoprotegerina/metabolismo , Transcriptoma , Idoso , Valva Aórtica/cirurgia , Estenose da Valva Aórtica/cirurgia , Sequência de Bases , Biomarcadores/metabolismo , Calcinose/cirurgia , Estudos de Casos e Controles , Ácidos Nucleicos Livres/genética , Matriz Extracelular/genética , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Osteopontina/genética , Osteoprotegerina/genética , RNA Mensageiro/genética , RNA-Seq
2.
Cancer Cell ; 41(4): 791-806.e4, 2023 04 10.
Artigo em Inglês | MEDLINE | ID: mdl-37037616

RESUMO

Immune checkpoint inhibitors (ICIs), including CTLA-4- and PD-1-blocking antibodies, can have profound effects on tumor immune cell infiltration that have not been consistent in biopsy series reported to date. Here, we analyze seven molecular datasets of samples from patients with advanced melanoma (N = 514) treated with ICI agents to investigate clinical, genomic, and transcriptomic features of anti-PD-1 response in cutaneous melanoma. We find that prior anti-CTLA-4 therapy is associated with differences in genomic, individual gene, and gene signatures in anti-PD-1 responders. Anti-CTLA-4-experienced melanoma tumors that respond to PD-1 blockade exhibit increased tumor mutational burden, inflammatory signatures, and altered cell cycle processes compared with anti-CTLA-4-naive tumors or anti-CTLA-4-experienced, anti-PD-1-nonresponsive melanoma tumors. We report a harmonized, aggregate resource and suggest that prior CTLA-4 blockade therapy is associated with marked differences in the tumor microenvironment that impact the predictive features of PD-1 blockade therapy response.


Assuntos
Melanoma , Neoplasias Cutâneas , Humanos , Melanoma/tratamento farmacológico , Melanoma/genética , Melanoma/metabolismo , Neoplasias Cutâneas/tratamento farmacológico , Neoplasias Cutâneas/genética , Antígeno CTLA-4/genética , Biomarcadores Tumorais , Imunoterapia , Microambiente Tumoral
3.
Nat Med ; 28(6): 1167-1177, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35662283

RESUMO

Chemotherapy combined with immunotherapy has improved the treatment of certain solid tumors, but effective regimens remain elusive for pancreatic ductal adenocarcinoma (PDAC). We conducted a randomized phase 2 trial evaluating the efficacy of nivolumab (nivo; anti-PD-1) and/or sotigalimab (sotiga; CD40 agonistic antibody) with gemcitabine/nab-paclitaxel (chemotherapy) in patients with first-line metastatic PDAC ( NCT03214250 ). In 105 patients analyzed for efficacy, the primary endpoint of 1-year overall survival (OS) was met for nivo/chemo (57.7%, P = 0.006 compared to historical 1-year OS of 35%, n = 34) but was not met for sotiga/chemo (48.1%, P = 0.062, n = 36) or sotiga/nivo/chemo (41.3%, P = 0.223, n = 35). Secondary endpoints were progression-free survival, objective response rate, disease control rate, duration of response and safety. Treatment-related adverse event rates were similar across arms. Multi-omic circulating and tumor biomarker analyses identified distinct immune signatures associated with survival for nivo/chemo and sotiga/chemo. Survival after nivo/chemo correlated with a less suppressive tumor microenvironment and higher numbers of activated, antigen-experienced circulating T cells at baseline. Survival after sotiga/chemo correlated with greater intratumoral CD4 T cell infiltration and circulating differentiated CD4 T cells and antigen-presenting cells. A patient subset benefitting from sotiga/nivo/chemo was not identified. Collectively, these analyses suggest potential treatment-specific correlates of efficacy and may enable biomarker-selected patient populations in subsequent PDAC chemoimmunotherapy trials.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica , Carcinoma Ductal Pancreático , Neoplasias Pancreáticas , Albuminas , Anticorpos Monoclonais/uso terapêutico , Antineoplásicos/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Carcinoma Ductal Pancreático/tratamento farmacológico , Carcinoma Ductal Pancreático/patologia , Humanos , Nivolumabe/uso terapêutico , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/patologia , Microambiente Tumoral , Neoplasias Pancreáticas
4.
Eur J Heart Fail ; 23(12): 2021-2032, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34632675

RESUMO

AIMS: Enhanced risk stratification of patients with aortic stenosis (AS) is necessary to identify patients at high risk for adverse outcomes, and may allow for better management of patient subgroups at high risk of myocardial damage. The objective of this study was to identify plasma biomarkers and multimarker profiles associated with adverse outcomes in AS. METHODS AND RESULTS: We studied 708 patients with calcific AS and measured 49 biomarkers using a Luminex platform. We studied the correlation between biomarkers and the risk of (i) death and (ii) death or heart failure-related hospital admission (DHFA). We also utilized machine-learning methods (a tree-based pipeline optimizer platform) to develop multimarker models associated with the risk of death and DHFA. In this cohort with a median follow-up of 2.8 years, multiple biomarkers were significantly predictive of death in analyses adjusted for clinical confounders, including tumour necrosis factor (TNF)-α [hazard ratio (HR) 1.28, P < 0.0001], TNF receptor 1 (TNFRSF1A; HR 1.38, P < 0.0001), fibroblast growth factor (FGF)-23 (HR 1.22, P < 0.0001), N-terminal pro B-type natriuretic peptide (NT-proBNP) (HR 1.58, P < 0.0001), matrix metalloproteinase-7 (HR 1.24, P = 0.0002), syndecan-1 (HR 1.27, P = 0.0002), suppression of tumorigenicity-2 (ST2) (IL1RL1; HR 1.22, P = 0.0002), interleukin (IL)-8 (CXCL8; HR 1.22, P = 0.0005), pentraxin (PTX)-3 (HR 1.17, P = 0.001), neutrophil gelatinase-associated lipocalin (LCN2; HR 1.18, P < 0.0001), osteoprotegerin (OPG) (TNFRSF11B; HR 1.26, P = 0.0002), and endostatin (COL18A1; HR 1.28, P = 0.0012). Several biomarkers were also significantly predictive of DHFA in adjusted analyses including FGF-23 (HR 1.36, P < 0.0001), TNF-α (HR 1.26, P < 0.0001), TNFR1 (HR 1.34, P < 0.0001), angiopoietin-2 (HR 1.26, P < 0.0001), syndecan-1 (HR 1.23, P = 0.0006), ST2 (HR 1.27, P < 0.0001), IL-8 (HR 1.18, P = 0.0009), PTX-3 (HR 1.18, P = 0.0002), OPG (HR 1.20, P = 0.0013), and NT-proBNP (HR 1.63, P < 0.0001). Machine-learning multimarker models were strongly associated with adverse outcomes (mean 1-year probability of death of 0%, 2%, and 60%; mean 1-year probability of DHFA of 0%, 4%, 97%; P < 0.0001). In these models, IL-6 (a biomarker of inflammation) and FGF-23 (a biomarker of calcification) emerged as the biomarkers of highest importance. CONCLUSIONS: Plasma biomarkers are strongly associated with the risk of adverse outcomes in patients with AS. Biomarkers of inflammation and calcification were most strongly related to prognosis.


Assuntos
Estenose da Valva Aórtica , Calcinose , Insuficiência Cardíaca , Biomarcadores , Humanos , Peptídeo Natriurético Encefálico , Fragmentos de Peptídeos , Prognóstico
5.
Mol Reprod Dev ; 76(1): 11-21, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18425777

RESUMO

Cells that morphologically and functionally resemble male germ cells can be spontaneously derived from ES cells. However, this process is inefficient and unpredictable suggesting that the expression pattern of male germ cell associated genes during spontaneous ES cell differentiation does not mimic the in vivo profiles of the genes. Thus, in the present study, the temporal profile of genes expressed at different stages of male germ cell development was examined in differentiating ES cells. The effect of all-trans retinoic acid (RA) which is a known inducer of primordial germ cell (PGC) proliferation/survival in vitro and testosterone which is required for spermatogenesis in vivo on the expression of these genes was also determined. Each of the 12 genes analyzed exhibited one of four temporal expression patterns in untreated differentiating ES cells: progressively decreased (Dppa3, Sycp3, Msy2), initially low and then increased (Stra8, Sycp1, Dazl, Act, Prm1), initially decreased and then increased (Piwil2, Tex14), or relatively unchanged (Akap3, Odf2). RA-treated cells exhibited increased expression of Stra8, Dazl, Act, and Prm1 and suppressed expression of Dppa3 compared to untreated controls. Furthermore, testosterone increased expression of Stra8 while the combination of RA and testosterone synergistically increased expression of Act. Our findings establish a comprehensive profile of male germ cell gene expression during spontaneous differentiation of murine ES cells and describe the capacity of RA and testosterone to modulate the expression of these genes. Furthermore, these data represent an important first step in designing a plausible directed differentiation protocol for male germ cells.


Assuntos
Células-Tronco Embrionárias/efeitos dos fármacos , Células-Tronco Embrionárias/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Espermatozoides/efeitos dos fármacos , Espermatozoides/metabolismo , Testosterona/farmacologia , Tretinoína/farmacologia , Animais , Biomarcadores , Adesão Celular/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Células Cultivadas , Células-Tronco Embrionárias/citologia , Perfilação da Expressão Gênica , Masculino , Camundongos
6.
Methods ; 45(2): 172-81, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18593614

RESUMO

The study of germ cell-specific gene regulation in vitro is challenging. Here we report that the promoter of the oocyte-specific gene, Gdf9, is active in a population of cultured murine embryonic stem cells (ES) which have a phenotype resembling oocytes. The promoter region of the murine Gdf9 coupled to enhanced green fluorescent protein (eGFP) was stably transfected into XX mouse ES cells. eGFP was expressed only in oocytes of chimeric mice generated from the transfected XX ES cells. The transfected ES cells were examined when cultured on feeder layers or as embryoid bodies. Large eGFP-positive cells, surrounded by a structure resembling a zona pellucida appeared transiently in cultures of the ES cells on feeder layers. Surprisingly, they were detectable on days 1 and 2 of culture but virtually absent on day 3. Addition of leukemia inhibitory factor (LIF) to the media significantly increased the number of eGFP-positive cels resembling oocytes. Quantitative-time PCR demonstrated a parallel increase in Gdf9 and Zp3 mRNA with changes in the abundance of eGFP-positive cells. In embryoid body cultures, eGFP-positive cells appeared transiently and then re-appeared in regional clusters after 30-45 days of culture. These findings demonstrate that a population of cultured murine ES cells contain the transcriptional machinery to drive expression of an oocyte-specific gene, and that those cells phenotypically resemble oocytes.


Assuntos
Células-Tronco Embrionárias/fisiologia , Peptídeos e Proteínas de Sinalização Intercelular/genética , Oócitos/fisiologia , Animais , Proteína Morfogenética Óssea 15 , Técnicas de Cultura de Células , Células Cultivadas , Células-Tronco Embrionárias/citologia , Células-Tronco Embrionárias/efeitos dos fármacos , Feminino , Expressão Gênica/efeitos dos fármacos , Expressão Gênica/genética , Genes Reporter , Proteínas de Fluorescência Verde/análise , Proteínas de Fluorescência Verde/genética , Fator 9 de Diferenciação de Crescimento , Fator Inibidor de Leucemia/farmacologia , Camundongos , Oócitos/metabolismo , Fenótipo , Regiões Promotoras Genéticas/genética , Transfecção/métodos
7.
Hum Gene Ther Methods ; 29(6): 237-250, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30351228

RESUMO

Recombinant adeno associated viruses (rAAV) have become an important tool for the delivery of gene therapeutics due to long-standing safety and success in clinical trials. Since humans often become exposed to AAVs and develop anti-AAV antibodies (Abs), a potential impediment to the success of gene therapeutics is neutralization of the viral particle before it has had a chance to bind and enter target cells to release the transgene. Identification of subjects with preexisting Abs having neutralizing potential, and exclusion of such subjects from clinical studies is expected to enhance drug efficacy. In vitro cell-based reporter assays are most often employed to determine the level of neutralizing antibodies in a given population. Such assays measure the ability of the Abs to prevent viral binding and entry into cells by engaging epitopes on the viral capsid involved in host cell receptor binding. In general, cell-based assays are low throughput and labor intensive and may suffer from high variability and low sensitivity issues. In contrast, enzyme-linked immunosorbent assays (ELISAs) are simpler, less variable, and have higher throughput. Demonstrating a correlation between neutralizing Abs assessed by a cell-based assay and total binding Abs measured in an ELISA will enable the use and substitution of the latter for screening and exclusion of subjects. In this work, we describe the development of a highly sensitive, specific, robust, and reproducible chemiluminescent ELISA method for the detection of total anti-AAV9 Abs. Using this method, we analyzed the prevalence of preexisting anti-AAV9 Abs in 100 serum samples from heart disease patients. Analysis of neutralizing Abs in the same samples using an in vitro cell-based assay showed a strong correlation between total anti-AAV9 Abs and neutralizing Abs, indicating the feasibility of using the total Ab ELISA in the future for patient screening and exclusion.


Assuntos
Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Dependovirus/imunologia , Luciferases de Vaga-Lume/metabolismo , Animais , Biomarcadores/sangue , Linhagem Celular , Cricetinae , Cricetulus , Dependovirus/genética , Ensaio de Imunoadsorção Enzimática/métodos , Ensaio de Imunoadsorção Enzimática/normas , Humanos , Luciferases de Vaga-Lume/genética , Luminescência , Sensibilidade e Especificidade , Sorogrupo
8.
Cell Metab ; 24(2): 223-33, 2016 08 09.
Artigo em Inglês | MEDLINE | ID: mdl-27508871

RESUMO

The development of LXR agonists for the treatment of coronary artery disease has been challenged by undesirable properties in animal models. Here we show the effects of an LXR agonist on lipid and lipoprotein metabolism and neutrophils in human subjects. BMS-852927, a novel LXRß-selective compound, had favorable profiles in animal models with a wide therapeutic index in cynomolgus monkeys and mice. In healthy subjects and hypercholesterolemic patients, reverse cholesterol transport pathways were induced similarly to that in animal models. However, increased plasma and hepatic TG, plasma LDL-C, apoB, apoE, and CETP and decreased circulating neutrophils were also evident. Furthermore, similar increases in LDL-C were observed in normocholesterolemic subjects and statin-treated patients. The primate model markedly underestimated human lipogenic responses and did not predict human neutrophil effects. These studies demonstrate both beneficial and adverse LXR agonist clinical responses and emphasize the importance of further translational research in this area.


Assuntos
Movimento Celular , Imidazóis/efeitos adversos , Imidazóis/farmacologia , Metabolismo dos Lipídeos , Lipoproteínas/metabolismo , Receptores X do Fígado/agonistas , Neutrófilos/metabolismo , Transportador 1 de Cassete de Ligação de ATP/genética , Transportador 1 de Cassete de Ligação de ATP/metabolismo , Membro 1 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/genética , Membro 1 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/metabolismo , Tecido Adiposo/metabolismo , Adolescente , Adulto , Animais , Movimento Celular/efeitos dos fármacos , Colesterol/sangue , Colesterol/metabolismo , Voluntários Saudáveis , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacologia , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Hipercolesterolemia/sangue , Hipercolesterolemia/tratamento farmacológico , Imidazóis/uso terapêutico , Contagem de Leucócitos , Lipoproteínas/sangue , Macaca fascicularis , Macrófagos/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Sistema Fagocitário Mononuclear/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos , Triglicerídeos/sangue , Adulto Jovem
9.
Endocrinology ; 143(8): 2986-94, 2002 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12130564

RESUMO

LH receptor activation leads to the phosphorylation/activation of p42/44 MAPK in preovulatory granulosa cells. As the LH receptor can activate both adenylyl cyclase and phospholipase C, we hypothesized that the LH receptor could elicit phosphorylation of p42/44 MAPK through activation of protein kinase A (PKA) and/or protein kinase C (PKC). Preovulatory granulosa cells in serum-free primary cultures were treated with ovulatory concentrations of human chorionic gonadotropin (hCG), an LH receptor agonist, with or without various inhibitors. The PKA inhibitor H89 as well as the myristoylated PKA inhibitor peptide PKI strongly inhibited hCG-stimulated p42/44 MAPK phosphorylation, whereas the PKC inhibitor GF109203X had no effect on p42/44 MAPK phosphorylation. LH receptor-stimulated phosphorylation of cAMP response element-binding protein (CREB), histone H3, and MAPK kinase (MEK) was also strongly inhibited by H89 and not by GF109203X. The extent of PKC activation was assessed in preovulatory granulosa cells using three criteria: translocation of PKC isoforms to the membrane fraction, phosphorylation of a known PKC substrate, and autophosphorylation of PKC delta on an activation-related site. By all three criteria PKCs were partially activated before hCG stimulation, and hCG treatment failed to elicit further PKC activation, in vitro or in vivo. Taken together, these results indicate that, under primary culture conditions where physiological levels of signaling proteins are present, hCG signals to activate MEK, p42/44 MAPK, CREB, and histone H3 in a predominantly PKA-dependent and PKC-independent manner. Unexpectedly, PKCs were partially activated in the absence of LH receptor activation, and LH receptor activation did not elicit further detectable PKC activation.


Assuntos
Peptídeos e Proteínas de Sinalização Intracelular , MAP Quinase Quinase Quinase 1 , Proteínas de Membrana , Proteína Quinase C/fisiologia , Receptores do LH/fisiologia , Animais , Células Cultivadas , Gonadotropina Coriônica/farmacologia , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Proteínas Quinases Dependentes de AMP Cíclico/fisiologia , Ativação Enzimática , Glucosidases , Histonas/metabolismo , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Substrato Quinase C Rico em Alanina Miristoilada , Fosfoproteínas/metabolismo , Fosforilação , Proteínas Serina-Treonina Quinases/metabolismo , Ratos , Ratos Sprague-Dawley
11.
J Biol Chem ; 279(26): 27621-32, 2004 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-15056665

RESUMO

A-kinase anchoring proteins (AKAPs) function to target protein kinase A (PKA) to specific locations within the cell. AKAPs are functionally identified by their ability to bind the type II regulatory subunits (RII) of PKA in an in vitro overlay assay. We previously showed that follicle-stimulating hormone (FSH) induces the expression of an 80-kDa AKAP (AKAP 80) in ovarian granulosa cells as they mature from a preantral to a preovulatory phenotype. In this report, we identify AKAP 80 as microtubule-associated protein 2D (MAP2D), a low molecular weight splice variant of the neuronal MAP2 protein. MAP2D is induced in granulosa cells by dexamethasone and by FSH in a time-dependent manner that mimics that of AKAP 80, and immunoprecipitation of MAP2D depletes extracts of AKAP 80. MAP2D is the only MAP2 protein present in ovaries and is localized to granulosa cells of preovulatory follicles and to luteal cells. MAP2D is concentrated at the Golgi apparatus along with RI and RII and, based on coimmunoprecipitation results, appears to bind both RI and RII in granulosa cells. Reduced expression of MAP2D resulting from treatment of granulosa cells with antisense oligonucleotides to MAP2 inhibited the phosphorylation of cAMP-response element-binding protein. These results suggest that this classic neuronal RII AKAP is a dual RI/RII AKAP that performs unique functions in ovarian granulosa cells that contribute to the preovulatory phenotype.


Assuntos
Proteínas de Transporte/metabolismo , Células da Granulosa/metabolismo , Proteínas Associadas aos Microtúbulos/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Animais , Encéfalo/metabolismo , Proteínas de Transporte/química , Proteínas de Transporte/genética , Diferenciação Celular , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Dexametasona/farmacologia , Feminino , Hormônio Foliculoestimulante/farmacologia , Expressão Gênica/efeitos dos fármacos , Complexo de Golgi/metabolismo , Complexo de Golgi/ultraestrutura , Células da Granulosa/efeitos dos fármacos , Proteínas Associadas aos Microtúbulos/química , Proteínas Associadas aos Microtúbulos/genética , Proteínas do Tecido Nervoso/química , Proteínas do Tecido Nervoso/genética , Ovário/citologia , Ovário/efeitos dos fármacos , Ovário/metabolismo , Ovário/ultraestrutura , Fosforilação , Isoformas de Proteínas , Ratos , Ratos Sprague-Dawley , Receptores do LH/metabolismo
12.
J Biol Chem ; 278(9): 7167-79, 2003 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-12493768

RESUMO

In this report we sought to elucidate the mechanism by which the follicle-stimulating hormone (FSH) receptor signals to promote activation of the p42/p44 extracellular signal-regulated protein kinases (ERKs) in granulosa cells. Results show that the ERK kinase MEK and upstream intermediates Raf-1, Ras, Src, and L-type Ca(2+) channels are already partially activated in vehicle-treated cells and that FSH does not further activate them. This tonic stimulatory pathway appears to be restrained at the level of ERK by a 100-kDa phosphotyrosine phosphatase that associates with ERK in vehicle-treated cells and promotes dephosphorylation of its regulatory Tyr residue, resulting in ERK inactivation. FSH promotes the phosphorylation of this phosphotyrosine phosphatase and its dissociation from ERK, relieving ERK from inhibition and resulting in its activation by the tonic stimulatory pathway and consequent translocation to the nucleus. Consistent with this premise, FSH-stimulated ERK activation is inhibited by the cell-permeable protein kinase A-specific inhibitor peptide Myr-PKI as well as by inhibitors of MEK, Src, a Ca(2+) channel blocker, and chelation of extracellular Ca(2+). These results suggest that FSH stimulates ERK activity in immature granulosa cells by relieving an inhibition imposed by a 100-kDa phosphotyrosine phosphatase.


Assuntos
Hormônio Foliculoestimulante/farmacologia , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Proteínas Tirosina Fosfatases/metabolismo , Sulfonamidas , Animais , Northern Blotting , Western Blotting , Cálcio/metabolismo , Bloqueadores dos Canais de Cálcio/farmacologia , Núcleo Celular/metabolismo , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Citosol/metabolismo , Ativação Enzimática , Inibidores Enzimáticos/farmacologia , Feminino , Células da Granulosa/metabolismo , Isoquinolinas/farmacologia , Sistema de Sinalização das MAP Quinases , Microscopia de Fluorescência , Modelos Biológicos , Ovário/enzimologia , Fosforilação , Testes de Precipitina , Ligação Proteica , Transporte Proteico , Proteínas Proto-Oncogênicas B-raf , Proteínas Proto-Oncogênicas c-raf/metabolismo , Ratos , Ratos Sprague-Dawley , Ovinos , Transdução de Sinais , Fatores de Tempo , Tirosina/química
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