RESUMO
In sickle cell disease (SCD), heme released during intravascular hemolysis promotes oxidative stress, inflammation, and vaso-occlusion. Conversely, free heme can also activate expression of antioxidant and globin genes. Heme binds to the transcription factor BACH1, which represses NRF2-mediated gene transcription. ASP8731, is a selective small molecule inhibitor of BACH1. We investigated the ability of ASP8731 to modulate pathways involved in SCD pathophysiology. In HepG2 liver cells, ASP8731 increased HMOX1 and FTH1 mRNA. In pulmonary endothelial cells, ASP8731 decreased VCAM1 mRNA in response to TNF-α and blocked a decrease in glutathione in response to hemin. Townes-SS mice were gavaged once per day for 4 weeks with ASP8731, hydroxyurea (HU) or vehicle. Both ASP8731 and HU inhibited heme-mediated microvascular stasis and in combination, ASP8731 significantly reduced microvascular stasis compared to HU alone. In Townes-SS mice, ASP8731 and HU markedly increased heme oxygenase-1 and decreased hepatic ICAM-1, NF-kB phospho-p65 protein expression in the liver, and white blood cell counts. In addition, ASP8731 increased gamma-globin expression and HbF+ cells (F-cells) as compared to vehicle-treated mice. In human erythroid differentiated CD34+ cells, ASP8731 increased HGB mRNA and increased the percentage of F-cells 2-fold in manner similar to HU. ASP8731 and HU when given together induced more HbF+ cells compared to either drug alone. In CD34+ cells from one donor that was non-responsive to HU, ASP8731 induced HbF+ cells ~2-fold. ASP8731 and HU also increased HBG and HBA, but not HBB mRNA in erythroid differentiated CD34+ cells derived from SCD patients. These data indicate that BACH1 may offer a new therapeutic target to treat SCD.
RESUMO
Mutations in G protein-coupled receptors (GPCRs) underlie numerous diseases. Many cause receptor misfolding and failure to reach the cell surface. Pharmacological chaperones are cell-permeant small molecules that engage nascent mutant GPCRs in the endoplasmic reticulum, stabilizing folding and "rescuing" cell surface expression. We previously demonstrated rescue of cell surface expression of luteinizing hormone receptor mutants by an allosteric agonist. Here we demonstrate that a similar approach can be employed to rescue mutant follicle-stimulating hormone receptors (FSHRs) with poor cell surface expression using a small-molecule FSHR agonist, CAN1404. Seventeen FSHR mutations described in patients with reproductive dysfunction were expressed in HEK 293T cells, and cell surface expression was determined by enzyme-linked immunosorbent assay of epitope-tagged FSHRs before/after treatment with CAN1404. Cell surface expression was severely reduced to ≤18% of wild-type (WT) for 11, modestly reduced to 66% to 84% of WT for 4, and not reduced for 2. Of the 11 with severely reduced cell surface expression, restoration to ≥57% of WT levels was achieved for 6 by treatment with 1 µM CAN1404 for 24 h, and a corresponding increase in FSH-induced signaling was observed for 4 of these, indicating restored functionality. Therefore, CAN1404 acts as a pharmacological chaperone and can rescue cell surface expression and function of certain mutant FSHRs with severely reduced cell surface expression. These findings aid in advancing the understanding of the effects of genetic mutations on GPCR function and provide a proof of therapeutic principle for FSHR pharmacological chaperones.
Assuntos
Membrana Celular/metabolismo , Receptores do FSH/genética , Receptores do FSH/metabolismo , Animais , Células CHO , Membrana Celular/efeitos dos fármacos , Membrana Celular/genética , Cricetinae , Cricetulus , Hormônio Foliculoestimulante/farmacologia , Células HEK293 , Humanos , Mutação com Perda de Função/genética , Proteínas Mutantes/genética , Proteínas Mutantes/metabolismo , Mutação , Receptores do FSH/agonistas , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genéticaRESUMO
Endometriosis is characterized by the presence of elevated proinflammatory cytokines such as tumor necrosis factor (TNF) alpha in the peritoneal cavity. Blocking interaction of TNFalpha with its receptor by the addition of excess TNFalpha-binding protein (TBP)-1 (a soluble form of TNF receptor-1) was effective in animal models of endometriosis. Recently, a novel, high-affinity inhibitor of TNFalpha, TNF-soluble high-affinity receptor complex (TNF-SHARC), was created by fusing TBP to both the alpha and beta subunits of inactive human chorionic gonadotropin. This dimeric protein was effective in inhibiting collagen-induced arthritis in mice. In the present study, the efficacy of TNF-SHARC in cellular and in vivo models of endometriosis was examined. TBP and TNF-SHARC dose-dependently inhibited TNFalpha-induced secretion of interleukin (IL)-6, IL-8, granulocyte macrophage-colony-stimulating factor, and monocyte chemoattractant protein-1 in immortalized human endometriotic cells. An in vivo mouse model of experimentally induced endometriosis using cycling C57BL/6 mice was established. Antide treatment (0.5 mg/kg), used as positive control, initiated 7 days after the establishment of the disease, reduced the weight of the lesions compared with control. TNF-SHARC at 3 mg/kg was not effective in inhibiting the disease, whereas at 9 mg/kg there was reduction in the lesion weight. In addition, antide and TNF-SHARC treatment in vivo increased in vitro natural killer cell activity compared with untreated animals. Thus, we provide evidence for supporting the development of TNF-SHARC as a therapeutic candidate for treating endometriosis in human.
Assuntos
Endometriose/tratamento farmacológico , Receptores Tipo I de Fatores de Necrose Tumoral/genética , Proteínas Recombinantes de Fusão/uso terapêutico , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Animais , Linhagem Celular , Gonadotropina Coriônica Humana Subunidade beta/genética , Citocinas/biossíntese , Citotoxicidade Imunológica , Endometriose/imunologia , Endometriose/patologia , Endométrio/efeitos dos fármacos , Endométrio/metabolismo , Endométrio/patologia , Feminino , Subunidade alfa de Hormônios Glicoproteicos/genética , Humanos , Células Matadoras Naturais/efeitos dos fármacos , Células Matadoras Naturais/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/farmacologia , Fator de Necrose Tumoral alfa/farmacologiaRESUMO
Tumor necrosis factor (TNF)-alpha is central to the endometriotic disease process. TNF-alpha receptor signaling regulates epithelial cell secretion of inflammation and invasion mediators. Because epithelial cells are a disease-inducing component of the endometriotic lesion, we explored the response of 12Z immortalized human epithelial endometriotic cells to TNF-alpha. This report reveals the impact of disruption of established TNF-alpha-induced signaling cascades on the expression of biomarkers of inflammation and epithelial-mesenchymal transition (EMT) from endometriotic epithelial cells. Note that we show the molecular potential of soluble TNF-R1 [TNF binding protein (TBP)] and a panel of small molecule kinase inhibitors to block endometriotic gene expression directly. The TNF-alpha receptor is demonstrated to signal through IkappaB kinase complex (IKK) 2 > IkappaB > nuclear factor kappaB, extracellular signal-regulated kinase > mitogen-activated protein kinase kinase (MEK), p38, and phosphatidylinositol 3-kinase (PI3K) > Akt1/2. TNF-alpha induces the expression of transcripts for inflammatory mediators interleukin (IL)-6, IL-8, regulated on activation normal T cell expressed and secreted, TNF-alpha, granulocyte macrophage-colony-stimulating factor (GM-CSF), and monocyte chemoattractant protein (MCP)-1 and also invasion mediators matrix metalloproteinase (MMP)-7, MMP-9, and intracellular adhesion molecule-1. Indeed, TBP inhibits the TNF-alpha-induced expression of all the above endometriotic genes in 12Z endometriotic epithelial cells. The secretion of IL-6, IL-8, GMCSF, and MCP-1 by TNF-alpha is blocked by TBP. Interestingly, MEK, p38, and IKK inhibitors block TNF-alpha-induced IL-8, IL-6, and GM-CSF secretion and 12z invasion, whereas the PI3K inhibitors do not. The only inhibitor to block MCP-1 expression is the p38 inhibitor. Last, TBP, MEK inhibitor, or p38 inhibitor also block cell surface expression of N-cadherin, a marker of mesenchymal cells. Taken together, these results demonstrate that interruption of TNF-alpha-induced signaling pathways in human endometriotic epithelial cells results in decreased expression and secretion of biomarkers for inflammation, EMT, and disease progression.
Assuntos
Endometriose/enzimologia , Endometriose/patologia , Células Epiteliais/enzimologia , Mesoderma/enzimologia , NF-kappa B/metabolismo , Fator de Necrose Tumoral alfa/farmacologia , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Caderinas/metabolismo , Linhagem Celular , Quimiocina CCL2/metabolismo , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Células Epiteliais/patologia , Matriz Extracelular/efeitos dos fármacos , Matriz Extracelular/enzimologia , Feminino , Fator Estimulador de Colônias de Granulócitos e Macrófagos/metabolismo , Humanos , Quinase I-kappa B/antagonistas & inibidores , Inflamação , Mediadores da Inflamação/metabolismo , Interleucina-6/metabolismo , Interleucina-8/metabolismo , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Mesoderma/efeitos dos fármacos , Inibidores de Fosfoinositídeo-3 Quinase , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas c-akt/antagonistas & inibidores , Receptores Tipo I de Fatores de Necrose Tumoral/farmacologia , Transcrição Gênica/efeitos dos fármacos , Proteínas Quinases p38 Ativadas por Mitógeno/antagonistas & inibidoresRESUMO
Follicle-stimulating hormone receptor (FSHR) belongs to the leucine-rich repeat family of the G protein-coupled receptor (LGR), which includes the glycoprotein hormone receptors luteinizing hormone receptor, thyrotropin receptor, and other LGRs 4, 5, 6, and 7. FSH is the key regulator of folliculogenesis in females and spermatogenesis in males. FSH elicits its physiological response through its cognate receptor on the cell surface. Binding of the hormone FSH to its receptor FSHR brings about conformational changes in the receptor that are transduced through the transmembrane domain to the intracellular region, where the downstream effector interaction takes place, leading to activation of the downstream signaling cascade. Identification of small molecules that could activate or antagonize FSHR provided interesting tools to study the signal transduction mechanism of the receptor. However, because of the nature of the ligand-receptor interaction of FSH-FSHR, which contains multiple sites in the extracellular binding domain, most of the small-molecule modulators of FSHR are unable to bind to the orthosteric site of the receptors. Rather they modulate receptor activation through allosteric sites in the transmembrane region. This review will discuss allosteric modulation of FSHR primarily through the discovery of small-molecule modulators, focusing on current data on the status of development and the utility of these as tools to better understand signaling mechanisms.
Assuntos
Regulação Alostérica/fisiologia , Hormônio Foliculoestimulante/metabolismo , Receptores do FSH/metabolismo , Transdução de Sinais/fisiologia , Humanos , Ligação Proteica , Receptores do LH/metabolismoRESUMO
Endometriosis is an estrogen (ER)-dependent gynecological disease caused by the growth of endometrial tissue at extrauterine sites. Current endocrine therapies address the estrogenic aspect of disease and offer some relief from pain but are associated with significant side effects. Immune dysfunction is also widely believed to be an underlying contributor to the pathogenesis of this disease. This study evaluated an inhibitor of c-Jun N-terminal kinase, bentamapimod (AS602801), which interrupts immune pathways, in 2 rodent endometriosis models. Treatment of nude mice bearing xenografts biopsied from women with endometriosis (BWE) with 30 mg/kg AS602801 caused 29% regression of lesion. Medroxyprogesterone acetate (MPA) or progesterone (PR) alone did not cause regression of BWE lesions, but combining 10 mg/kg AS602801 with MPA caused 38% lesion regression. In human endometrial organ cultures (from healthy women), treatment with AS602801 or MPA reduced matrix metalloproteinase-3 (MMP-3) release into culture medium. In organ cultures established with BWE, PR or MPA failed to inhibit MMP-3 secretion, whereas AS602801 alone or MPA + AS602801 suppressed MMP-3 production. In an autologous rat endometriosis model, AS602801 caused 48% regression of lesions compared to GnRH antagonist Antide (84%). AS602801 reduced inflammatory cytokines in endometriotic lesions, while levels of cytokines in ipsilateral horns were unaffected. Furthermore, AS602801 enhanced natural killer cell activity, without apparent negative effects on uterus. These results indicate that bentamapimod induced regression of endometriotic lesions in endometriosis rodent animal models without suppressing ER action. c-Jun N-terminal kinase inhibition mediated a comprehensive reduction in cytokine secretion and moreover was able to overcome PR resistance.
Assuntos
Benzotiazóis/uso terapêutico , Endometriose/tratamento farmacológico , Endométrio/efeitos dos fármacos , Inibidores Enzimáticos/uso terapêutico , Proteínas Quinases JNK Ativadas por Mitógeno/antagonistas & inibidores , Pirimidinas/uso terapêutico , Adulto , Animais , Benzotiazóis/farmacologia , Citocinas/metabolismo , Modelos Animais de Doenças , Endometriose/metabolismo , Endométrio/metabolismo , Inibidores Enzimáticos/farmacologia , Feminino , Humanos , Células Matadoras Naturais/efeitos dos fármacos , Células Matadoras Naturais/metabolismo , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Metaloproteinase 3 da Matriz/metabolismo , Acetato de Medroxiprogesterona/farmacologia , Acetato de Medroxiprogesterona/uso terapêutico , Camundongos , Camundongos Nus , Progesterona/farmacologia , Progesterona/uso terapêutico , Pirimidinas/farmacologia , RatosRESUMO
Glycoprotein hormones, follicle-stimulating hormone (FSH), luteinizing hormone (LH), and thyroid-stimulating hormone (TSH) are heterodimeric proteins with a common α-subunit and hormone-specific ß-subunit. These hormones are dominant regulators of reproduction and metabolic processes. Receptors for the glycoprotein hormones belong to the family of G protein-coupled receptors. FSH receptor (FSHR) and LH receptor are primarily expressed in somatic cells in ovary and testis to promote egg and sperm production in women and men, respectively. TSH receptor is expressed in thyroid cells and regulates the secretion of T3 and T4. Glycoprotein hormones bind to the large extracellular domain of the receptor and cause a conformational change in the receptor that leads to activation of more than one intracellular signaling pathway. Several small molecules have been described to activate/inhibit glycoprotein hormone receptors through allosteric sites of the receptor. Small molecule allosteric modulators have the potential to be administered orally to patients, thus improving the convenience of treatment. It has been a challenge to develop a small molecule allosteric agonist for glycoprotein hormones that can mimic the agonistic effects of the large natural ligand to activate similar signaling pathways. However, in the past few years, there have been several promising reports describing distinct chemical series with improved potency in preclinical models. In parallel, proposal of new structural model for FSHR and in silico docking studies of small molecule ligands to glycoprotein hormone receptors provide a giant leap on the understanding of the mechanism of action of the natural ligands and new chemical entities on the receptors. This review will focus on the current status of small molecule allosteric modulators of glycoprotein hormone receptors, their effects on common signaling pathways in cells, their utility for clinical application as demonstrated in preclinical models, and use of these molecules as novel tools to dissect the molecular signaling pathways of these receptors.
RESUMO
OBJECTIVE: To design a high-throughput cell assay to identify molecules modulating adhesion induced by tumor necrosis factor alpha (TNF-alpha) of endometrial cells to mesothelium. DESIGN: Prospective study. SETTING: Biotech company. PATIENT(S): Bovine endometrial (BEND) and human mesothelial cells. INTERVENTION(S): Endometrial cells were treated with TNF-alpha and different proteins. MAIN OUTCOME MEASURE(S): TNF-alpha increased binding of fibronectin-coated fluorescein isothiocyanate (FITC) beads. The ability of various proteins to inhibit TNF-alpha-induced fibronectin-bead binding was measured. RESULT(S): Treatment of BEND cells with TNF-alpha increased binding of fibronectin-coated beads. Addition of TNF-alpha-binding protein abrogated the effect of TNF-alpha in a dose-dependent manner. The initial screen of 1014 proteins identified interferon-alpha2 (IFN-alpha2), inteleukin-17 (IL-17), transforming growth factor beta (TGF-beta), and platelet-derived growth factor (PDGF) as inhibiting TNF-alpha-induced bead binding. Interferon-alpha2, IL-17, and TGF-beta inhibited bead-binding with an IC50 (ng/mL, mean +/- SD) of 0.15 +/- 0.11, 0.098 +/- 0.008, and 5.91 +/- 0.72, respectively. All three isoforms of PDGF (AA, AB, and BB) were also found to inhibit TNF-alpha-induced bead-binding, with IC50s (ng/mL) of 1.8 +/- 0.45, 10.0 +/- 1.49, and 1.72 +/- 0.73, respectively. CONCLUSION(S): We describe a novel high-throughput cell-based assay for endometrial cell binding to fibronectin. We show that IFN-alpha, IL-17, TGF-beta, and PDGF have inhibitory actions on adhesion of endometrial cells to fibronectin.