RESUMEN
Combination therapies or multi-targeted drugs have been pointed out as an option to prevent the emergence of resistant clones, which could make long-term treatment more effective and translate into better clinical outcomes for cancer patients. The NT157 compound is a synthetic tyrphostin that leads to long-term inhibition of IGF1R/IRS1-2-, STAT3- and AXL-mediated signaling pathways. Given the importance of these signaling pathways for the development and progression of lung cancer, this disease becomes an interesting model for generating preclinical evidence on the cellular and molecular mechanisms underlying the antineoplastic activity of NT157. In lung cancer cells, exposure to NT157 decreased, in a dose-dependent manner, cell viability, clonogenicity, cell cycle progression and migration, and induced apoptosis (p < 0.05). In the molecular scenario, NT157 reduced expression of IRS1 and AXL and phosphorylation of p38 MAPK, AKT, and 4EBP1. Besides, NT157 decreased expression of oncogenes BCL2, CCND1, MYB, and MYC and increased genes related to cellular stress and apoptosis, JUN, BBC3, CDKN1A, CDKN1B, FOS, and EGR1 (p < 0.05), favoring a tumor-suppressive cell signaling network in the context of lung cancer. Of note, JNK was identified as a key kinase for NT157-induced IRS1 and IRS2 phosphorylation, revealing a novel axis involved in the mechanism of action of the drug. NT157 also presented potentiating effects on EGFR inhibitors in lung cancer cells. In conclusion, our preclinical findings highlight NT157 as a putative prototype of a multitarget drug that may contribute to the antineoplastic arsenal against lung cancer.
Asunto(s)
Antineoplásicos , Neoplasias Pulmonares , Pirogalol/análogos & derivados , Sulfonamidas/farmacología , Antineoplásicos/farmacología , Antineoplásicos/uso terapéutico , Apoptosis , Línea Celular Tumoral , Receptores ErbB/farmacología , Humanos , Neoplasias Pulmonares/tratamiento farmacológico , MAP Quinasa Quinasa 4/metabolismo , Proteínas Proto-Oncogénicas c-akt , Proteínas Proto-Oncogénicas c-bcl-2 , Proto-Oncogenes , Pirogalol/farmacología , Proteínas Tirosina Quinasas Receptoras/metabolismo , Transducción de Señal , Tirfostinos/farmacología , Proteínas Quinasas p38 Activadas por MitógenosRESUMEN
Parkinson's disease (PD) is characterized by motor impairment and dopaminergic neuronal loss. There is no cure for the disease, and treatments have several limitations. The transient receptor potential melastatin 2 (TRPM2), a calcium-permeable non-selective cation channel, has been reported to be upregulated in neuronal death. However, there are no in vivo studies evaluating TRPM2's role and neuroprotective effects in PD. Here, we test the hypothesis that TRPM2 is upregulated in the 6-hydroxydopamine (6-OHDA) mouse model of PD and that its inhibition, by the AG490, is neuroprotective. For that, AG490 or vehicle were intraperitoneally administered into C57BL/6 mice. Mice then received 6-OHDA into the right striatum. Motor behavior assessments were evaluated 6, 13, and 20 days after surgery using the cylinder and apomorphine-induced rotational testes, and 7, 14, and 21 days after surgery using rotarod test. Brain samples of substantia nigra (SNc) and striatum (CPu) were collected for immunohistochemistry and immunoblotting on days 7 and 21. We showed that TRPM2 protein expression was upregulated in 6-OHDA-treated animals. In addition, AG490 prevented dopaminergic neuron loss, microglial activation, and astrocyte reactivity in 6-OHDA-treated animals. The compound improved motor behaviors and Akt/GSK-3ß/caspase-3 signaling. We conclude that TRPM2 inhibition by AG490 is neuroprotective in the 6-OHDA model and that the TRPM2 channel may represent a potential therapeutic target for PD.
Asunto(s)
Fármacos Neuroprotectores , Enfermedad de Parkinson , Canales Catiónicos TRPM , Animales , Modelos Animales de Enfermedad , Neuronas Dopaminérgicas/metabolismo , Glucógeno Sintasa Quinasa 3 beta/metabolismo , Ratones , Ratones Endogámicos C57BL , Fármacos Neuroprotectores/metabolismo , Fármacos Neuroprotectores/farmacología , Fármacos Neuroprotectores/uso terapéutico , Oxidopamina/farmacología , Enfermedad de Parkinson/tratamiento farmacológico , Enfermedad de Parkinson/metabolismo , Sustancia Negra/metabolismo , Canales Catiónicos TRPM/metabolismo , TirfostinosRESUMEN
BACKGROUND AND AIMS: The liver is a highly regenerative organ, but its regenerative capacity is compromised in severe liver injury settings. In chronic liver diseases, the number of liver progenitor cells (LPCs) correlates proportionally to disease severity, implying that their inefficient differentiation into hepatocytes exacerbates the disease. Moreover, LPCs secrete proinflammatory cytokines; thus, their prolonged presence worsens inflammation and induces fibrosis. Promoting LPC-to-hepatocyte differentiation in patients with advanced liver disease, for whom liver transplantation is currently the only therapeutic option, may be a feasible clinical approach because such promotion generates more functional hepatocytes and concomitantly reduces inflammation and fibrosis. APPROACH AND RESULTS: Here, using zebrafish models of LPC-mediated liver regeneration, we present a proof of principle of such therapeutics by demonstrating a role for the epidermal growth factor receptor (EGFR) signaling pathway in differentiation of LPCs into hepatocytes. We found that suppression of EGFR signaling promoted LPC-to-hepatocyte differentiation through the mitogen-activated ERK kinase (MEK)-extracellular signal-regulated kinase (ERK)-sex-determining region Y-box 9 (SOX9) cascade. Pharmacological inhibition of EGFR or MEK/ERK promoted LPC-to-hepatocyte differentiation as well as genetic suppression of the EGFR-ERK-SOX9 axis. Moreover, Sox9b overexpression in LPCs blocked their differentiation into hepatocytes. In the zebrafish liver injury model, both hepatocytes and biliary epithelial cells contributed to LPCs. EGFR inhibition promoted the differentiation of LPCs regardless of their origin. Notably, short-term treatment with EGFR inhibitors resulted in better liver recovery over the long term. CONCLUSIONS: The EGFR-ERK-SOX9 axis suppresses LPC-to-hepatocyte differentiation during LPC-mediated liver regeneration. We suggest EGFR inhibitors as a proregenerative therapeutic drug for patients with advanced liver disease.
Asunto(s)
Receptores ErbB/metabolismo , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Regeneración Hepática/efectos de los fármacos , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Factor de Transcripción SOX9/metabolismo , Células Madre/metabolismo , Pez Cebra/metabolismo , Animales , Animales Modificados Genéticamente , Butadienos/farmacología , Diferenciación Celular/efectos de los fármacos , Inhibidores Enzimáticos/farmacología , Receptores ErbB/antagonistas & inhibidores , Quinasas MAP Reguladas por Señal Extracelular/antagonistas & inhibidores , Hepatocitos/citología , Nitrilos/farmacología , Quinazolinas/farmacología , Células Madre/citología , Tirfostinos/farmacologíaRESUMEN
A member of the Trk family of neurotrophin receptors, tropomyosin receptor kinase B (TrkB, encoded by the NTRK2 gene) is an increasingly important target in various cancer types, including glioblastoma (GBM). EGFR is among the most frequently altered oncogenes in GBM, and EGFR inhibition has been tested as an experimental therapy. Functional interactions between EGFR and TrkB have been demonstrated. In the present study, we investigated the role of TrkB and EGFR, and their interactions, in GBM. Analyses of NTRK2 and EGFR gene expression from The Cancer Genome Atlas (TCGA) datasets showed an increase in NTRK2 expression in the proneural subtype of GBM, and a strong correlation between NTRK2 and EGFR expression in glioma CpG island methylator phenotype (G-CIMP+) samples. We showed that when TrkB and EGFR inhibitors were combined, the inhibitory effect on A172 human GBM cells was more pronounced than when either inhibitor was given alone. When U87MG GBM cells were xenografted into the flank of nude mice, tumor growth was delayed by treatment with TrkB and EGFR inhibitors, given alone or combined, only at specific time points. Intracranial GBM growth in mice was not significantly affected by drug treatments. Our findings indicate that correlations between NTRK2 and EGFR expression occur in specific GBM subgroups. Also, our results using cultured cells suggest for the first time the potential of combining TrkB and EGFR inhibition for the treatment of GBM.
Asunto(s)
Antineoplásicos/farmacología , Neoplasias Encefálicas/metabolismo , Inhibidores Enzimáticos/farmacología , Glioblastoma/metabolismo , Glicoproteínas de Membrana/metabolismo , Inhibidores de Proteínas Quinasas/farmacología , Receptor trkB/metabolismo , Animales , Azepinas/farmacología , Benzamidas/farmacología , Neoplasias Encefálicas/genética , Ciclo Celular/efectos de los fármacos , Ciclo Celular/genética , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Supervivencia Celular/genética , Sinergismo Farmacológico , Receptores ErbB/antagonistas & inhibidores , Receptores ErbB/genética , Receptores ErbB/metabolismo , Glioblastoma/genética , Humanos , Glicoproteínas de Membrana/antagonistas & inhibidores , Glicoproteínas de Membrana/genética , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , Clasificación del Tumor , Quinazolinas/farmacología , Receptor trkB/antagonistas & inhibidores , Receptor trkB/genética , Tirfostinos/farmacología , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
The epidermal growth factor receptor (EGFR) pathway is directly involved in oocyte meiotic resumption induced by a gonadotropic stimulus. Here, we used an EGFR inhibitor (AG1478) to inhibit spontaneous meiosis resumption in bovine oocytes (EGFR- group) during 8 hr prematuration and assessed the competence of such oocytes for embryonic development, apoptosis and gene expression in comparison with Control group which was not prematured. Data are presented as mean ± SEM. Blastocysts rate on day 7 (40.81%, averaged) and hatching rate on day 9 (77.35%, averaged) were unaffected by treatment (p > 0.05). Similarly, treatment did not affect (p > 0.05) the total cell number on day 7 (119.05, averaged) and on day 9 (189.5, averaged). Apoptosis was reduced (p < 0.05) in EGFR- group day 7-embryos compared to Control group (3.7% ± 1.0 vs. 5.2% ± 0.8). Abundance of several transcripts was upregulated (p < 0.05) in EGFR- group, including genes related to embryo development and quality (NANOG and RPLP0), epigenetic regulation (H2AFZ), apoptosis (BID) and stress response (GPX4 and HIF1A). Taken together, the results presented here demonstrated a reduction in the apoptosis index and upregulation of NANOG, H2AFZ and RPLP0 mRNA levels, which are related to embryonic development. Our data suggest that temporary meiosis blockage with EGFR inhibitor during prematuration culture of bovine oocytes may be an interesting strategy to improve embryo quality.
Asunto(s)
Inhibidores Enzimáticos/farmacología , Factor de Crecimiento Epidérmico/antagonistas & inhibidores , Regulación del Desarrollo de la Expresión Génica/efectos de los fármacos , Técnicas de Maduración In Vitro de los Oocitos/veterinaria , Quinazolinas/farmacología , Tirfostinos/farmacología , Animales , Bovinos , Embrión de Mamíferos , Desarrollo Embrionario , Femenino , Fertilización In VitroRESUMEN
Molecules containing an (cyanovinyl)arene moiety are known as tyrphostins because of their ability to inhibit proteins from the tyrosine kinase family, an interesting target for the development of anticancer and trypanocidal drugs. In the present work, (E)-(cyanovinyl)benzeneboronic acids were synthesized by Knoevenagel condensations without the use of any catalysts in water through a simple protocol that completely avoided the use of organic solvents in the synthesis and workup process. The inâ vitro anticancer and trypanocidal activities of the synthesized boronic acids were also evaluated, and it was discovered that the introduction of the boronic acid functionality improved the activity of the boronic tyrphostins. Inâ silico target fishing with the use of a chemogenomic approach suggested that tyrosine-phosphorylation-regulated kinaseâ 1a (DYRK1A) was a potential target for some of the designed compounds.
Asunto(s)
Antineoplásicos/química , Antineoplásicos/farmacología , Compuestos de Boro/química , Compuestos de Boro/farmacología , Tripanocidas/química , Tripanocidas/farmacología , Tirfostinos/química , Tirfostinos/farmacología , Animales , Antineoplásicos/síntesis química , Compuestos de Boro/síntesis química , Línea Celular , Línea Celular Tumoral , Células Cultivadas , Enfermedad de Chagas/tratamiento farmacológico , Diseño de Fármacos , Humanos , Ratones , Modelos Moleculares , Neoplasias/tratamiento farmacológico , Proteínas Tirosina Quinasas/antagonistas & inhibidores , Tripanocidas/síntesis química , Trypanosoma cruzi/efectos de los fármacos , Tirfostinos/síntesis químicaRESUMEN
OBJECTIVE: Ewing sarcoma (ES) is a type of childhood cancer probably arising from stem mesenchymal or neural crest cells. The epidermal growth factor receptor (EGFR) acts as a driver oncogene in many types of solid tumors. However, its involvement in ES remains poorly understood. METHODS: Human SK-ES-1 and RD-ES ES cells were treated with EGF, the EGFR inhibitor tyrphostin (AG1478), or phosphoinositide 3-kinase (PI3K) or extracellular-regulated kinase (ERK)/mitogen-activated kinase (MAPK) inhibitors. Cell proliferation survival, cycle, and senescence were analyzed. The protein content of possible targets of EGFR manipulation was measured by Western blot. RESULTS: Cell proliferation and survival were increased by EGF and inhibited by AG1478. The EGFR inhibitor also altered the cell cycle, inducing arrest in G1 and increasing the sub-G1 population, reduced polyploidy and increased the population of senescent cells. In addition, AG1478 reduced the levels of phosphorylated AKT (p-AKT), ERK, p-ERK, cyclin D1, and brain-derived neurotrophic factor (BDNF), while enhancing p53 levels. Cell proliferation was also impaired by inhibitors of PI3K or ERK, alone or combined with AG1478. CONCLUSIONS: Our findings reveal novel aspects of EGFR regulation of ES cells and provide early evidence for antitumor activities of EGFR inhibitors in ES.
Asunto(s)
Neoplasias Óseas/patología , Proliferación Celular/efectos de los fármacos , Inhibidores Enzimáticos/farmacología , Receptores ErbB/metabolismo , Quinazolinas/farmacología , Sarcoma de Ewing/patología , Tirfostinos/farmacología , Factor Neurotrófico Derivado del Encéfalo/metabolismo , Línea Celular Tumoral , Ciclina D1/metabolismo , Factor de Crecimiento Epidérmico/farmacología , Receptores ErbB/antagonistas & inhibidores , Quinasas MAP Reguladas por Señal Extracelular/antagonistas & inhibidores , Puntos de Control de la Fase G1 del Ciclo Celular/efectos de los fármacos , Humanos , Inhibidores de las Quinasa Fosfoinosítidos-3 , Fosforilación/efectos de los fármacos , Transducción de Señal/efectos de los fármacos , Proteína p53 Supresora de Tumor/metabolismoRESUMEN
Leptin is an adipose-derived hormone that controls appetite and energy expenditure. Leptin receptors are expressed on extra-hypothalamic ventrobasal (VB) and reticular thalamic (RTN) nuclei from embryonic stages. Here, we studied the effects of pressure-puff, local application of leptin on both synaptic transmission and action potential properties of thalamic neurons in thalamocortical slices. We used whole-cell patch-clamp recordings of thalamocortical VB neurons from wild-type (WT) and leptin-deficient obese (ob/ob) mice. We observed differences in VB neurons action potentials and synaptic currents kinetics when comparing WT vs. ob/ob. Leptin reduced GABA release onto VB neurons throughout the activation of a JAK2-dependent pathway, without affecting excitatory glutamate transmission. We observed a rapid and reversible reduction by leptin of the number of action potentials of VB neurons via the activation of large conductance Ca2+-dependent potassium channels. These leptin effects were observed in thalamocortical slices from up to 5-week-old WT but not in leptin-deficient obese mice. Results described here suggest the existence of a leptin-mediated trophic modulation of thalamocortical excitability during postnatal development. These findings could contribute to a better understanding of leptin within the thalamocortical system and sleep deficits in obesity.
Asunto(s)
Potenciales de Acción/efectos de los fármacos , Leptina/farmacología , Neuronas/efectos de los fármacos , Núcleos Talámicos/citología , Núcleos Talámicos/metabolismo , Ácido gamma-Aminobutírico/metabolismo , 6-Ciano 7-nitroquinoxalina 2,3-diona/farmacología , Animales , Temperatura Corporal/efectos de los fármacos , Inhibidores Enzimáticos/farmacología , Antagonistas de Aminoácidos Excitadores/farmacología , Janus Quinasa 2/metabolismo , Leptina/deficiencia , Leptina/genética , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Neuronas/fisiología , Transducción de Señal/efectos de los fármacos , Bloqueadores de los Canales de Sodio/farmacología , Potenciales Sinápticos/efectos de los fármacos , Transmisión Sináptica/efectos de los fármacos , Tetrodotoxina/farmacología , Tirfostinos/farmacologíaRESUMEN
Estradiol-17ß-D-glucuronide (E17G), through the activation of different signaling proteins, induces acute endocytic internalization of canalicular transporters in rat, including multidrug resistance-associated protein 2 (Abcc2) and bile salt export pump (Abcb11), generating cholestasis. Insulin-like growth factor 1 receptor (IGF-1R) is a membrane-bound tyrosine kinase receptor that can potentially interact with proteins activated by E17G. The aim of this study was to analyze the potential role of IGF-1R in the effects of E17G in isolated perfused rat liver (IPRL) and isolated rat hepatocyte couplets. In vitro, IGF-1R inhibition by tyrphostin AG1024 (TYR, 100 nM), or its knock-down with siRNA, strongly prevented E17G-induced impairment of Abcc2 and Abcb11 function and localization. The protection by TYR was not additive to that produced by wortmannin (PI3K inhibitor, 100 nM), and both protections share the same dependency on microtubule integrity, suggesting that IGF-1R shared the signaling pathway of PI3K/Akt. Further analysis of the activation of Akt and IGF-1R induced by E17G indicated a sequence of activation GPR30-IGF-1R-PI3K/Akt. In IPRL, an intraportal injection of E17G triggered endocytosis of Abcc2 and Abcb11, and this was accompanied by a sustained decrease in the bile flow and the biliary excretion of Abcc2 and Abcb11 substrates. TYR did not prevent the initial decay, but it greatly accelerated the recovery to normality of these parameters and the reinsertion of transporters into the canalicular membrane. In conclusion, the activation of IGF-1R is a key factor in the alteration of canalicular transporter function and localization induced by E17G, and its activation follows that of GPR30 and precedes that of PI3K/Akt.
Asunto(s)
Colestasis/metabolismo , Estradiol/análogos & derivados , Hepatocitos/efectos de los fármacos , Receptor IGF Tipo 1/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Miembro 11 de la Subfamilia B de Transportador de Casetes de Unión al ATP/metabolismo , Transportadoras de Casetes de Unión a ATP/metabolismo , Animales , Células Cultivadas , Colestasis/inducido químicamente , Endocitosis , Estradiol/toxicidad , Femenino , Hepatocitos/metabolismo , Hígado/efectos de los fármacos , Fosfatidilinositol 3-Quinasas/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Interferencia de ARN , Ratas , Ratas Wistar , Transducción de Señal , Tirfostinos/farmacología , Wortmanina/farmacologíaRESUMEN
Arachidonic acid increased intracellular calcium, in cells expressing green fluorescent protein-tagged human FFA4 receptors, with an EC50 of ~40µM. This action was not blocked by cyclooxygenase or lipoxigenase inhibitors but it was inhibited by AH7614, a FFA4 antagonist. Arachidonic acid induced ERK activation accompanied by EGF receptor transactivation. However, EGF transactivation was not the major mechanism through which the fatty acid induced ERK phosphorylation, as evidenced by the inability of AG1478 to block it. Arachidonic acid increased FFA4 receptor phosphorylation that reached its maximum within 15min with an EC50 of ~30µM; inhibitors of protein kinase C partially diminish this effect and AH7614 blocked it. Arachidonic acid induced rapid and sustained Akt/PKB phosphorylation and FFA4 - ß-arrestin interaction. Confocal microscopy evidenced that FFA4 receptor activation and phosphorylation were associated to internalization. In conclusion, arachidonic acid is a bona fide FFA4 receptor agonist.
Asunto(s)
Ácido Araquidónico/farmacología , Receptores ErbB/metabolismo , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Calcio/metabolismo , Línea Celular , Células HEK293 , Humanos , Fosforilación , Quinazolinas/farmacología , Transducción de Señal/efectos de los fármacos , Tirfostinos/farmacología , beta-Arrestinas/metabolismoRESUMEN
Extracellular nucleotides are signaling elements present in the tumor microenvironment; however, their role in tumor growth is not completely understood. In the present study, we asked whether nucleotides regulate cell migration in ovarian carcinoma-derived cells. We observed that 100 µM UTP induced migration in SKOV-3 cells (1.57 ± 0.08 fold over basal), and RT-PCR showed expression of transcripts for the P2RY2 and P2RY4 receptors. Knockdown of P2RY2 expression in SKOV-3 cells (P2RY2-KD) abolished the UTP-induced migration. The mechanism activated by UTP to induce migration involves transactivation of the epidermal growth factor receptor (EGFR) since we observed that the EGFR kinase inhibitor AG1478 and the PI3K inhibitor Wortmannin inhibit this response (to 0.76 ± 0.23 and 0.46 ± 0.14 relative to the control, respectively). In agreement with these observations, UTP was able to modify the phosphorylation state of the EGFR; likewise, the induction of ERK1/2 phosphorylation promoted by UTP was abolished by a 30-60 min treatment with AG1478. Our data also suggested that the enhanced cell migration involves the epithelium to mesenchymal transition (EMT) process, since a 12 h stimulation of SKOV-3 cells with 100 µM UTP showed an increase in vimentin and SNAIL protein levels (459.8 ± 132.4% over basal for SNAIL). Interestingly, treatment with apyrase (10 U/mL) reduces the migration of control cells and induces a considerable enrichment of E-cadherin in the cell-cell contacts, favoring an epithelial phenotype and strongly suggesting that the nucleotides released by tumor cells and acting through the P2RY2 receptor are potential regulators of invasiveness.
Asunto(s)
Células Epiteliales/efectos de los fármacos , Transición Epitelial-Mesenquimal/efectos de los fármacos , Receptores ErbB/genética , Regulación Neoplásica de la Expresión Génica , Receptor Cross-Talk/efectos de los fármacos , Receptores Purinérgicos P2Y2/genética , Uridina Trifosfato/farmacología , Androstadienos/farmacología , Cadherinas/genética , Cadherinas/metabolismo , Línea Celular Tumoral , Movimiento Celular/efectos de los fármacos , Células Epiteliales/metabolismo , Células Epiteliales/patología , Receptores ErbB/metabolismo , Femenino , Humanos , Proteína Quinasa 1 Activada por Mitógenos/antagonistas & inhibidores , Proteína Quinasa 1 Activada por Mitógenos/genética , Proteína Quinasa 1 Activada por Mitógenos/metabolismo , Proteína Quinasa 3 Activada por Mitógenos/antagonistas & inhibidores , Proteína Quinasa 3 Activada por Mitógenos/genética , Proteína Quinasa 3 Activada por Mitógenos/metabolismo , Ovario/efectos de los fármacos , Ovario/metabolismo , Ovario/patología , Fosfatidilinositol 3-Quinasas/genética , Fosfatidilinositol 3-Quinasas/metabolismo , Inhibidores de las Quinasa Fosfoinosítidos-3 , Fosforilación/efectos de los fármacos , Inhibidores de Proteínas Quinasas/farmacología , Quinazolinas/farmacología , Receptores Purinérgicos P2Y2/metabolismo , Transducción de Señal , Factores de Transcripción de la Familia Snail , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Tirfostinos/farmacología , Uridina Trifosfato/metabolismo , Vimentina/genética , Vimentina/metabolismo , WortmaninaRESUMEN
Estradiol-17ß-D-glucuronide (E17G) induces acute endocytic internalization of canalicular transporters, including multidrug resistance-associated protein 2 (Abcc2) in rat, generating cholestasis. Several proteins organized in at least two different signaling pathways are involved in E17G cholestasis: one pathway involves estrogen receptor alpha (ERα), Ca(2+)-dependent protein kinase C and p38-mitogen activated protein kinase, and the other pathway involves GPR30, PKA, phosphoinositide 3-kinase/AKT and extracellular signal-related kinase 1/2. EGF receptor (EGFR) can potentially participate in both pathways since it interacts with GPR30 and ERα. Hence, the aim of this study was to analyze the potential role of this receptor and its downstream effectors, members of the Src family kinases in E17G-induced cholestasis. In vitro, EGFR inhibition by Tyrphostin (Tyr), Cl-387785 or its knockdown with siRNA strongly prevented E17G-induced impairment of Abcc2 function and localization. Activation of EGFR was necessary but not sufficient to impair the canalicular transporter function, whereas the simultaneous activation of EGFR and GPR30 could impair Abcc2 transport. The protection of Tyr was not additive to that produced by the ERα inhibitor ICI neither with that produced by Src kinase inhibitors, suggesting that EGFR shared the signaling pathway of ERα and Src. Further analysis of ERα, EGFR and Src activations induced by E17G, demonstrated that ERα activation precedes that of EGFR and EGFR activation precedes that of Src. In conclusion, activation of EGFR is a key factor in the alteration of canalicular transporter function and localization induced by E17G and it occurs before that of Src and after that of ERα.
Asunto(s)
Transportadoras de Casetes de Unión a ATP/metabolismo , Receptores ErbB/metabolismo , Estradiol/análogos & derivados , Receptor alfa de Estrógeno/metabolismo , Hepatocitos/metabolismo , Animales , Canalículos Biliares/efectos de los fármacos , Canalículos Biliares/metabolismo , Canalículos Biliares/fisiopatología , Células Cultivadas , Colestasis/inducido químicamente , Colestasis/metabolismo , Receptores ErbB/genética , Estradiol/metabolismo , Estradiol/farmacología , Antagonistas del Receptor de Estrógeno/farmacología , Femenino , Fulvestrant , Técnicas de Silenciamiento del Gen , Hepatocitos/efectos de los fármacos , Quinazolinas/farmacología , Ratas , Ratas Wistar , Tirfostinos/farmacología , Familia-src Quinasas/metabolismoRESUMEN
Staphylococcus aureus is an important human pathogen that causes infections that may present high morbidity and mortality. Among its many virulence factors protein A (SpA) and Staphylococcal binding immunoglobulin protein (Sbi) bind the Fc portion of IgG interfering with opsonophagocytosis. We have previously demonstrated that SpA interacts with the TNF-α receptor (TNFR) 1 through each of the five IgG binding domains and induces the production of pro-inflammatory cytokines and chemokines. The IgG binding domains of Sbi are homologous to those of SpA, which allow us to hypothesize that Sbi might also have a role in the inflammatory response induced by S. aureus. We demonstrate that Sbi is a novel factor that participates in the induction of the inflammatory response during staphylococcal infections via TNFR1 and EGFR mediated signaling as well as downstream MAPKs. The expression of Sbi significantly contributed to IL-6 production and modulated CXCL-1 expression as well as neutrophil recruitment to the site of infection, thus demonstrating for the first time its relevance as a pro-inflammatory staphylococcal antigen in an in vivo model.
Asunto(s)
Proteínas Bacterianas/inmunología , Proteínas Portadoras/inmunología , Inflamación/inmunología , Infecciones Estafilocócicas/inmunología , Proteína Estafilocócica A/inmunología , Staphylococcus aureus/inmunología , Animales , Sitios de Unión de Anticuerpos/inmunología , Quimiocina CXCL1/biosíntesis , Receptores ErbB/inmunología , Quinasas MAP Reguladas por Señal Extracelular/antagonistas & inhibidores , Femenino , Flavonoides/farmacología , Imidazoles/farmacología , Inmunoglobulina G/inmunología , Inflamación/microbiología , Interleucina-6/biosíntesis , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Ratones Transgénicos , Infiltración Neutrófila/inmunología , Inhibidores de Proteínas Quinasas/farmacología , Piridinas/farmacología , Quinazolinas/farmacología , Receptores Tipo I de Factores de Necrosis Tumoral/genética , Receptores Tipo I de Factores de Necrosis Tumoral/inmunología , Transducción de Señal/inmunología , Tirfostinos/farmacología , Factores de Virulencia/metabolismo , Proteínas Quinasas p38 Activadas por Mitógenos/antagonistas & inhibidoresRESUMEN
The platelet-derived growth factor (PDGF) system is crucial for blood vessel stability. In the present study, we evaluated whether PDGFs play a critical intraovarian survival role in gonadotropin-dependent folliculogenesis. We examined the effect of intrabursal administration of a selective platelet-derived growth factor receptor (PDGFR) inhibitor (AG1295) on follicular development, proliferation, apoptosis and blood vessel formation and stability in ovaries from rats treated with equine chorionic gonadotropin (eCG). The percentages of preantral follicles (PAFs) and early antral follicles (EAFs) were lower in AG1295-treated ovaries than in control ovaries (p < 0.01-0.05). The percentage of atretic follicles (AtrFs) increased in AG1295-treated ovaries compared to control (p < 0.05). The ovarian weight and estradiol concentrations were lower in AG1295-treated ovaries than in the control group (p < 0.01 and p < 0.05, respectively), whereas progesterone concentrations did not change. AG1295 decreased the proliferation index in EAFs (p < 0.05) and increased the percentage of nuclei positive for cleaved caspase-3 and apoptotic DNA fragmentation (p < 0.01-0.05). AG1295 increased the expression of Bax (p < 0.05) without changes in the expression of Bcl-2 protein. AG1295-treated ovaries increased the cleavage of caspase-8 (p < 0.05) and decreased AKT and BAD phosphorylation compared with control ovaries (p < 0.05). AG1295 caused a decrease not only in the endothelial cell area but also in the area of pericytes and vascular smooth muscle cells (VSMCs) in the ovary (p < 0.05). Our findings suggest that the local inhibition of PDGFs causes an increase in ovarian apoptosis through an imbalance in the ratio of antiapoptotic to proapoptotic proteins, thus leading a larger number of follicles to atresia. PDGFs could exert their mechanism of action through an autocrine/paracrine effect on granulosa and theca cells mediated by PDGFRs. In conclusion, these data clearly indicate that the PDGF system is necessary for follicular development induced by gonadotropins.
Asunto(s)
Apoptosis , Proliferación Celular , Gonadotropina Coriónica/farmacología , Folículo Ovárico/fisiología , Receptores del Factor de Crecimiento Derivado de Plaquetas/antagonistas & inhibidores , Animales , Femenino , Caballos , Neovascularización Fisiológica , Folículo Ovárico/irrigación sanguínea , Ovario/irrigación sanguínea , Ovario/citología , Factor de Crecimiento Derivado de Plaquetas/fisiología , Ratas Sprague-Dawley , Maduración Sexual , Tirfostinos/farmacologíaRESUMEN
The aim of the present study was to investigate the anti-ovarian cancer effect of the inhibitor of signal transducer and activator of transcription 3 (STAT3), WP1066. Western blot was used to detect the phosphorylation of STAT3 in ovarian cancer cell line SKOV3 and cisplatin-resistant ovarian cancer cell line SKOV3/DDP. MTT and colony-forming assays were performed to evaluate the viability and growth of ovarian cancer cells. The apoptosis of ovarian cancer cells was determined by flow cytometry. The wound healing assay and Transwell assay were performed to examine the migration and invasion of ovarian cancer cells. WP1066 significantly inhibited the phosphorylation of STAT3 in SKOV3 and SKOV3/DDP cells. WP1066 treatment inhibited the proliferation and clonogenicity of both SKOV3 and SKOV3/DDP cells. After WP1066 treatment for 24 h, the apoptosis rates of SKOV3 and SKOV3/DDP cells were significantly increased compared with the control cells. After treatment with WP1066, the reduction of the wound gaps was significantly less in both SKOV3 and SKOV3/DDP cells. WP1066 also significantly inhibited the invasion capacity of SKOV3 and SKOV3/DDP cells compared with the control group. Treatment with WP1066 combined with cisplatin significantly increased proliferation inhibition and apoptosis in SKOV3 and SKOV3/ DDP cells compared with treatment with cisplatin alone. A synergistic action between WP1066 and cisplatin on the proliferation and apoptosis of ovarian cancer cells was determined. In conclusion, inhibition of STAT3 may suppress the proliferation, migration and invasion, induce apoptosis and enhance the chemosensitivity of ovarian cancer cells, indicating that STAT3 is a new therapeutic target of ovarian cancer.
Asunto(s)
Antineoplásicos/farmacología , Cisplatino/farmacología , Neoplasias Ováricas/tratamiento farmacológico , Piridinas/farmacología , Factor de Transcripción STAT3/antagonistas & inhibidores , Tirfostinos/farmacología , Antineoplásicos/uso terapéutico , Protocolos de Quimioterapia Combinada Antineoplásica/farmacología , Apoptosis/efectos de los fármacos , Línea Celular Tumoral , Movimiento Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Femenino , Humanos , Invasividad Neoplásica , Fosforilación , Piridinas/uso terapéutico , Tirfostinos/uso terapéuticoRESUMEN
Estrogens and tamoxifen do not only exert their effects at the genomic level, but also play a role at the cell membrane activating downstream signaling pathways. We recently characterized an estrogen receptor-positive epithelial murine breast cancer cell line, LM05-E. Utilizing this cell line and MCF-7 cells, we compared the non-genomic effects of estradiol and 4-OH-tamoxifen. We showed that, similar to estradiol, tamoxifen activated the MAPK/ERK 1/2 pathway; however, we did not find activation of PI3K/AKT by either estradiol or tamoxifen. Short-term treatments with estradiol stimulated, whereas tamoxifen inhibited cell proliferation. Using pharmacological inhibitors we showed that the effect of estradiol was mediated by the MAPK/ERK 1/2 pathway, but that inhibition of this pathway did not affect tamoxifen. Surprisingly, however, blocking of PI3K/AKT signaling interfered with the inhibitory effect of tamoxifen. Analysis of the involvement of the EGFR support previous findings that designate this receptor as a mediator of the non-genomic effects of estradiol; blocking EGFR also reverses the inhibitory effect of tamoxifen. Finally, matrix metalloproteinases (MMPs) were confirmed to be involved in the proliferative effect of estradiol. These results demonstrated the novel non-genomic effects of tamoxifen and revealed that pathways downstream of EGFR and PI3K/AKT are involved in the inhibition of cell proliferation. Caution should be exercised when analyzing strategies that aim at combining endocrine therapy with specific signaling inhibitors.
Asunto(s)
Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/metabolismo , Estradiol/farmacología , Tamoxifeno/análogos & derivados , Animales , Neoplasias de la Mama/patología , Línea Celular Tumoral/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Receptores ErbB/antagonistas & inhibidores , Receptores ErbB/metabolismo , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Femenino , Humanos , Células MCF-7/efectos de los fármacos , Ratones , Fosfatidilinositol 3-Quinasas/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Quinazolinas/farmacología , Transducción de Señal/efectos de los fármacos , Tamoxifeno/farmacología , Tirfostinos/farmacologíaRESUMEN
Synaptic transmission in the sympathetic nervous system is a plastic process modulated by different factors. We characterized the effects of brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) on basal transmission and ganglionic long-term potentiation (LTP) in the rat superior cervical ganglion. LTP was elicited by supramaximal tetanic stimulation (40 Hz, 3 s) of the sympathetic trunk and was quantified by measuring LTP decay time and LTP extent. Neurotrophins did not affect basal transmission, however, they differentially affected LTP. BDNF (200 ng/ml) increased LTP decay time and LTP extent 2.0-fold (p < 0.01). In contrast, NGF showed a dual effect: 200 ng/ml NGF reduced LTP decay time and LTP extent to 53% and to 32% of control value (p < 0.0001 and p < 0.02; respectively), whereas >350 ng/ml NGF significantly increased LTP decay time and LTP extent (p < 0.02). Digital analysis of compound action potentials suggests that neurotrophins could change the synchronization of unitary action potentials. Pharmacological data obtained in intact ganglia show that C2-ceramide produced a 2-fold enhancement in LTP, whereas tyrphostin AG879, an inhibitor of tyrosine kinase activity, reversed the NGF blockade and produced by itself an enhancement in LTP. In sliced ganglia we observed that an anti-TrkA antibody reversed the NGF-induced LTP blockade. Immunohistochemistry studies revealed that 83% of ganglionic neurons express TrkA, whereas 52% express p75 receptor, and 18% express TrkB receptor. We propose that p75 neurotrophin receptors and probably TrkB signaling enhance LTP, whereas TrkA signaling reduces it.
Asunto(s)
Factor Neurotrófico Derivado del Encéfalo/farmacología , Potenciación a Largo Plazo/efectos de los fármacos , Factor de Crecimiento Nervioso/farmacología , Neuronas/efectos de los fármacos , Ganglio Cervical Superior/citología , Potenciales de Acción/efectos de los fármacos , Animales , Ceramidas/farmacología , Relación Dosis-Respuesta a Droga , Estimulación Eléctrica , Masculino , Factor de Crecimiento Nervioso/metabolismo , Proteínas del Tejido Nervioso , Ratas , Ratas Wistar , Receptor trkA/metabolismo , Receptor trkB/metabolismo , Receptores de Factores de Crecimiento , Receptores de Factor de Crecimiento Nervioso/metabolismo , Tirfostinos/farmacologíaRESUMEN
In the heart, insulin-like growth factor-1 (IGF-1) is a peptide with pro-hypertrophic and anti-apoptotic actions. The pro-hypertrophic properties of IGF-1 have been attributed to the extracellular regulated kinase (ERK) pathway. Recently, we reported that IGF-1 also increases intracellular Ca(2+) levels through a pertussis toxin (PTX)-sensitive G protein. Here we investigate whether this Ca(2+) signal is involved in IGF-1-induced cardiomyocyte hypertrophy. Our results show that the IGF-1-induced increase in Ca(2+) level is abolished by the IGF-1 receptor tyrosine kinase inhibitor AG538, PTX and the peptide inhibitor of Gßγ signaling, ßARKct. Increases in the activities of Ca(2+) -dependent enzymes calcineurin, calmodulin kinase II (CaMKII), and protein kinase Cα (PKCα) were observed at 5 min after IGF-1 exposure. AG538, PTX, ßARKct, and the dominant negative PKCα prevented the IGF-1-dependent phosphorylation of ERK1/2. Participation of calcineurin and CaMKII in ERK phosphorylation was discounted. IGF-1-induced cardiomyocyte hypertrophy, determined by cell size and ß-myosin heavy chain (ß-MHC), was prevented by AG538, PTX, ßARKct, dominant negative PKCα, and the MEK1/2 inhibitor PD98059. Inhibition of calcineurin with CAIN did not abolish IGF-1-induced cardiac hypertrophy. We conclude that IGF-1 induces hypertrophy in cultured cardiomyocytes by activation of the receptor tyrosine kinase activity/ßγ-subunits of a PTX-sensitive G protein/Ca(2+) /PKCα/ERK pathway without the participation of calcineurin.
Asunto(s)
Calcio/metabolismo , Cardiomegalia/metabolismo , Proteínas de Unión al GTP Heterotriméricas/metabolismo , Factor I del Crecimiento Similar a la Insulina/metabolismo , Miocitos Cardíacos/patología , Animales , Calcineurina/genética , Calcineurina/metabolismo , Señalización del Calcio/efectos de los fármacos , Proteína Quinasa Tipo 2 Dependiente de Calcio Calmodulina/metabolismo , Cardiomegalia/inducido químicamente , Cardiomegalia/patología , Catecoles/farmacología , Células Cultivadas , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Factor I del Crecimiento Similar a la Insulina/farmacología , Miocitos Cardíacos/efectos de los fármacos , Miocitos Cardíacos/metabolismo , Péptidos/genética , Fosforilación/efectos de los fármacos , Proteína Quinasa C-alfa/metabolismo , Subunidades de Proteína , Ratas Sprague-Dawley , Receptor IGF Tipo 1/antagonistas & inhibidores , Receptor IGF Tipo 1/metabolismo , Proteínas Recombinantes/genética , Tirfostinos/farmacologíaRESUMEN
Warm ischemia/reperfusion (I/R) is a common clinical problem during liver transplantation and liver resection. Warm ischemia also occurs during trauma and shock. However, there is still no safe and promising strategy for protecting the liver from I/R injury. Signal transducer and activator of transcription 3 (STAT3) is a major immediate response molecule for protecting cell survival. In this study, we first confirmed that a pharmacological STAT3 inhibitor, (E)-2-cyano-3-(3,4-dihydrophenyl)-N-(phenylmethyl)-2-propenamide (AG490), significantly reduced the survival of HepG2 cells, regardless of the serum condition. Furthermore, we created hepatocyte-specific STAT3-deficient mice with the cyclization recombination-locus of X-over P1 (Cre-LoxP) system to study the mechanisms of STAT3 in liver I/R injury. We found that the alanine aminotransferase level was significantly higher in hepatocyte-specific STAT3-deficient mice versus wild-type (WT) mice in a 70% liver I/R injury model. A histopathological examination showed that hepatocyte-specific STAT3-deficient mice suffered more severe damage than WT mice despite similar numbers of polymorphonuclear neutrophils in the 2 groups. These results indicate that endogenous STAT3 signaling in hepatocytes is required for protection of the liver in vitro and in vivo against warm I/R injury. In conclusion, endogenous STAT3 plays an important role in protecting the liver against I/R injury, and STAT3-targeting therapy could be a therapeutic approach to combating liver I/R injury.
Asunto(s)
Hepatocitos/metabolismo , Trasplante de Hígado/métodos , Daño por Reperfusión/metabolismo , Factor de Transcripción STAT3/metabolismo , Alanina Transaminasa/metabolismo , Animales , Proliferación Celular , Supervivencia Celular , Modelos Animales de Enfermedad , Genotipo , Células Hep G2 , Hepatocitos/citología , Hepatocitos/patología , Humanos , Isquemia/patología , Hígado/patología , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Neutrófilos/citología , Fosforilación , Daño por Reperfusión/patología , Factor de Transcripción STAT3/antagonistas & inhibidores , Tirosina/química , Tirfostinos/farmacología , Isquemia TibiaRESUMEN
The role played by prolactin (PRL) in fish immunity is scant. We report here that stimulation of the Atlantic salmon monocytic cell line SHK-1 with native salmon PRL resulted in activation of the respiratory burst and induction of the expression of the genes encoding the phagocyte NADPH oxidase components p47phox, p67phox and gp91phox, and the transcription factor IFN regulatory factor-1 (IRF-1). Interestingly, the pharmacologic inhibition of the Jak/Stat signaling pathway with AG490 blocked reactive oxygen species (ROS) production, and the induction of genes encoding the NADPH oxidase components and IRF-1 in PRL-activated SHK-1 cells. In addition, PRL promoted the phosphorylation of Stat and induced the DNA binding activity of IRF-1. These results, together with the presence of several consensus target motifs for Stat and IRF-1 in the promoter of the tilapia p47phox gene, suggest that PRL regulates p47phox gene expression in fish through the activation of these two key transcription factors. Taken together, our results demonstrate that PRL induces the expression of the genes encoding the major phagocyte NADPH oxidase components and ROS production in fish macrophages via the JAK2/Stat/IRF-1 signaling pathway.