RESUMEN
Ferroptosis is a newly described form of regulated cell death triggered by oxidative stresses and characterized by extensive lipid peroxidation and membrane damages. The name of ferroptosis indicates that the ferroptotic death process depends on iron, but not other metals, as one of its canonical features. Here, we reported that zinc is also essential for ferroptosis in breast and renal cancer cells. Zinc chelator suppressed ferroptosis, and zinc addition promoted ferroptosis, even during iron chelation. By interrogating zinc-related genes in a genome-wide RNAi screen of ferroptosis, we identified SLC39A7, encoding ZIP7 that controls zinc transport from endoplasmic reticulum (ER) to cytosol, as a novel genetic determinant of ferroptosis. Genetic and chemical inhibition of the ZIP7 protected cells against ferroptosis, and the ferroptosis protection upon ZIP7 knockdown can be abolished by zinc supplementation. We found that the genetic and chemical inhibition of ZIP7 triggered ER stresses, including the induction of the expression of HERPUD1 and ATF3. Importantly, the knockdown of HERPUD1 abolished the ferroptosis protection phenotypes of ZIP7 inhibition. Together, we have uncovered an unexpected role of ZIP7 in ferroptosis by maintaining ER homeostasis. These findings may have therapeutic implications for human diseases involving ferroptosis and zinc dysregulations.
Asunto(s)
Neoplasias de la Mama/metabolismo , Carcinoma de Células Renales/metabolismo , Proteínas de Transporte de Catión/metabolismo , Retículo Endoplásmico/metabolismo , Ferroptosis , Neoplasias Renales/metabolismo , Zinc/metabolismo , Neoplasias de la Mama/genética , Neoplasias de la Mama/patología , Carcinoma de Células Renales/genética , Carcinoma de Células Renales/patología , Proteínas de Transporte de Catión/antagonistas & inhibidores , Proteínas de Transporte de Catión/genética , Línea Celular Tumoral , Quelantes/farmacología , Retículo Endoplásmico/genética , Retículo Endoplásmico/patología , Femenino , Ferroptosis/efectos de los fármacos , Regulación Neoplásica de la Expresión Génica , Humanos , Neoplasias Renales/genética , Neoplasias Renales/patología , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismoRESUMEN
In ß-thalassemia, ineffective erythropoiesis leads to anemia and systemic iron overload. The management of iron overload by chelation therapy is a standard of care. However, iron chelation does not improve the ineffective erythropoiesis. We recently showed that the oral ferroportin inhibitor VIT-2763 ameliorates anemia and erythropoiesis in the Hbbth3/+ mouse model of ß-thalassemia. In this study, we investigated whether concurrent use of the iron chelator deferasirox (DFX) and the ferroportin inhibitor VIT-2763 causes any pharmacodynamic interactions in the Hbbth3/+ mouse model of ß-thalassemia. Mice were treated with VIT-2763 or DFX alone or with the combination of both drugs once daily for three weeks. VIT-2763 alone or in combination with DFX improved anemia and erythropoiesis. VIT-2763 alone decreased serum iron and transferrin saturation (TSAT) but was not able to reduce the liver iron concentration. While DFX alone had no effect on TSAT and erythropoiesis, it significantly reduced the liver iron concentration alone and in the presence of VIT-2763. Our results clearly show that VIT-2763 does not interfere with the iron chelation efficacy of DFX. Furthermore, VIT-2763 retains its beneficial effects on improving ineffective erythropoiesis when combined with DFX in the Hbbth3/+ mouse model. In conclusion, co-administration of the oral ferroportin inhibitor VIT-2763 and the iron chelator DFX is feasible and might offer an opportunity to improve both ineffective erythropoiesis and iron overload in ß-thalassemia.
Asunto(s)
Bencimidazoles/farmacología , Eritropoyesis/efectos de los fármacos , Oxazoles/farmacología , Piridinas/farmacología , Talasemia beta/tratamiento farmacológico , Administración Oral , Animales , Bencimidazoles/administración & dosificación , Bencimidazoles/efectos adversos , Bencimidazoles/uso terapéutico , Proteínas de Transporte de Catión/antagonistas & inhibidores , Células Cultivadas , Deferasirox/administración & dosificación , Deferasirox/farmacología , Deferasirox/uso terapéutico , Combinación de Medicamentos , Interacciones Farmacológicas , Femenino , Hierro/sangre , Quelantes del Hierro/administración & dosificación , Quelantes del Hierro/farmacología , Quelantes del Hierro/uso terapéutico , Masculino , Ratones , Ratones Endogámicos C57BL , Oxazoles/administración & dosificación , Oxazoles/efectos adversos , Oxazoles/uso terapéutico , Piridinas/administración & dosificación , Piridinas/efectos adversos , Piridinas/uso terapéutico , Transferrina/metabolismoRESUMEN
Zinc is an essential trace element and participates in a variety of biological processes. ZnT (SLC30) family members are generally responsible for zinc efflux across the membrane regulating zinc homeostasis. In mammals, the only predominantly plasma membrane resident ZnT has been reported to be ZnT1, and ZnT1-/ZnT1- mice die at the embryonic stage. In Drosophila, knock down of ZnT1 homologue (dZnT1//ZnT63C/CG17723) results in growth arrest under zinc-limiting conditions. To investigate the essentiality of dZnT1 for zinc homeostasis, as well as its role in dietary zinc uptake especially under normal physiological conditions, we generated dZnT1 mutants by the CRISPER/Cas9 method. Homozygous mutant dZnT1 is lethal, with substantial zinc accumulation in the iron cell region, posterior midgut as well as gastric caeca. Expression of human ZnT1 (hZnT1), in the whole body or in the entire midgut, fully rescued the dZnT1 mutant lethality, whereas tissue-specific expression of hZnT1 in the iron cell region and posterior midgut partially rescued the developmental defect of the dZnT1 mutant. Supplementation of zinc together with clioquinol or hinokitiol conferred a limited but observable rescue upon dZnT1 loss. Our work demonstrated the absolute requirement of dZnT1 in Drosophila survival and indicated that the most essential role of dZnT1 is in the gut.
Asunto(s)
Proteínas de Transporte de Catión/metabolismo , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/metabolismo , Zinc/metabolismo , Animales , Animales Modificados Genéticamente , Sistemas CRISPR-Cas , Proteínas de Transporte de Catión/antagonistas & inhibidores , Proteínas de Transporte de Catión/genética , Dieta , Proteínas de Drosophila/antagonistas & inhibidores , Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Drosophila melanogaster/crecimiento & desarrollo , Femenino , Técnicas de Silenciamiento del Gen , Genes de Insecto , Humanos , Absorción Intestinal/genética , Absorción Intestinal/fisiología , Masculino , Mutación , Filogenia , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Oligoelementos/administración & dosificación , Oligoelementos/metabolismo , Oligoelementos/farmacocinética , Zinc/administración & dosificación , Zinc/farmacocinéticaRESUMEN
ß-Thalassemia is a genetic anemia caused by partial or complete loss of ß-globin synthesis, leading to ineffective erythropoiesis and RBCs with a short life span. Currently, there is no efficacious oral medication modifying anemia for patients with ß-thalassemia. The inappropriately low levels of the iron regulatory hormone hepcidin enable excessive iron absorption by ferroportin, the unique cellular iron exporter in mammals, leading to organ iron overload and associated morbidities. Correction of unbalanced iron absorption and recycling by induction of hepcidin synthesis or treatment with hepcidin mimetics ameliorates ß-thalassemia. However, hepcidin modulation or replacement strategies currently in clinical development all require parenteral drug administration. We identified oral ferroportin inhibitors by screening a library of small molecular weight compounds for modulators of ferroportin internalization. Restricting iron availability by VIT-2763, the first clinical stage oral ferroportin inhibitor, ameliorated anemia and the dysregulated iron homeostasis in the Hbbth3/+ mouse model of ß-thalassemia intermedia. VIT-2763 not only improved erythropoiesis but also corrected the proportions of myeloid precursors in spleens of Hbbth3/+ mice. VIT-2763 is currently being developed as an oral drug targeting ferroportin for the treatment of ß-thalassemia.
Asunto(s)
Proteínas de Transporte de Catión/antagonistas & inhibidores , Compuestos Férricos/administración & dosificación , Maltosa/análogos & derivados , Talasemia beta/tratamiento farmacológico , Administración Oral , Animales , Proteínas de Transporte de Catión/metabolismo , Línea Celular , Modelos Animales de Enfermedad , Perros , Evaluación Preclínica de Medicamentos , Eritropoyesis/efectos de los fármacos , Eritropoyesis/genética , Femenino , Hepcidinas/metabolismo , Humanos , Hierro/sangre , Hierro/metabolismo , Células de Riñón Canino Madin Darby , Masculino , Maltosa/administración & dosificación , Ratones , Ratones Endogámicos C57BL , Ratones Mutantes , Proteolisis/efectos de los fármacos , Ratas Sprague-Dawley , Ubiquitinación/efectos de los fármacos , Globinas beta/deficiencia , Globinas beta/genética , Talasemia beta/genética , Talasemia beta/metabolismoRESUMEN
Intracellular zinc concentrations are tightly regulated by the coordinated regulation of ZIPs and ZnTs. Very little is known about the regulation of these transporters in cardiomyocytes, in response to extracellular zinc. Adult rat cardiomyocytes express ZnTs 1, 2, 5, and 9, in addition to ZIPs 1, 2, 3, 6, 7, 9, 10, 11, 13, and 14. We have determined the intracellular free zinc levels using Zinpyr-1 fluorescence and studied response of ZIP and ZnT mRNA by real-time PCR to the changes in extracellular zinc and TPEN in adult rat ventricular myocytes. TPEN downregulated ZnT1, ZnT2, and ZIP11 mRNAs but upregulated ZnT5, ZIP2, ZIP7, ZIP10, ZIP13, and ZIP14 mRNAs. Zinc supplementation upregulated ZnT1, ZnT2 mRNA but downregulated ZnT5, ZIP1, ZIP2, ZIP3, ZIP7, ZIP9, and ZIP10 mRNA. The negative regulation of ZIPs by zinc excess can be explained in terms of zinc homeostasis as these transporters may act to protect cells from zinc over accumulation by reducing zinc influx when the extracellular concentration of zinc is high. Similarly, the ZnT expression appears to be regulated to avoid loss of zinc from the intracellular milieu, under zinc-deficient conditions.
Asunto(s)
Proteínas de Transporte de Catión/antagonistas & inhibidores , Etilenodiaminas/farmacología , Miocitos Cardíacos/efectos de los fármacos , Zinc/farmacología , Animales , Proteínas de Transporte de Catión/genética , Proteínas de Transporte de Catión/metabolismo , Supervivencia Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Etilenodiaminas/química , Etilenodiaminas/metabolismo , Masculino , Miocitos Cardíacos/metabolismo , ARN Mensajero/efectos de los fármacos , ARN Mensajero/genética , ARN Mensajero/metabolismo , Ratas , Ratas Wistar , Relación Estructura-Actividad , Zinc/química , Zinc/metabolismoRESUMEN
AIMS: Erythropoiesis-stimulating agents used to treat anaemia in patients with chronic kidney disease (CKD) have been associated with cardiovascular adverse events. Hepcidin production, controlled by bone morphogenic protein 6 (BMP6), regulates iron homeostasis via interactions with the iron transporter, ferroportin. High hepcidin levels are thought to contribute to increased iron sequestration and subsequent anaemia in CKD patients. To investigate alternative therapies to erythropoiesis-stimulating agents for CKD patients, monoclonal antibodies, LY3113593 and LY2928057, targeting BMP6 and ferroportin respectively, were tested in CKD patients. METHODS: Preclinical in vitro/vivo data and clinical data in healthy subjects and CKD patients were used to illustrate the translation of pharmacological properties of LY3113593 and LY2928057, highlighting the novelty of targeting these nodes within the hepcidin-ferroportin pathway. RESULTS: LY2928057 bound ferroportin and blocked interactions with hepcidin, allowing iron efflux, leading to increased serum iron and transferrin saturation levels and increased hepcidin in monkeys and humans. In CKD patients, LY2928057 led to slower haemoglobin decline and reduction in ferritin (compared to placebo). Serum iron increase was (mean [90% confidence interval]) 1.98 [1.46-2.68] and 1.36 [1.22-1.51] fold-relative to baseline following LY2928057 600 mg and LY311593 150 mg respectively in CKD patients. LY3113593 specifically blocked BMP6 binding to its receptor and produced increases in iron and transferrin saturation and decreases in hepcidin preclinically and clinically. In CKD patients, LY3113593 produced an increase in haemoglobin and reduction in ferritin (compared to placebo). CONCLUSION: LY3113593 and LY2928057 pharmacological effects (serum iron and ferritin) were translated from preclinical-to-clinical development. Such interventions may lead to new CKD anaemia treatments.
Asunto(s)
Anemia/tratamiento farmacológico , Fármacos Hematológicos/farmacología , Hepcidinas/metabolismo , Insuficiencia Renal Crónica/complicaciones , Transducción de Señal/efectos de los fármacos , Adulto , Anemia/sangre , Anemia/etiología , Anemia/metabolismo , Animales , Proteína Morfogenética Ósea 6/antagonistas & inhibidores , Proteína Morfogenética Ósea 6/metabolismo , Proteínas de Transporte de Catión/antagonistas & inhibidores , Proteínas de Transporte de Catión/metabolismo , Modelos Animales de Enfermedad , Evaluación Preclínica de Medicamentos , Femenino , Ferritinas/sangre , Ferritinas/metabolismo , Voluntarios Sanos , Fármacos Hematológicos/uso terapéutico , Hemoglobinas/análisis , Humanos , Hierro/sangre , Hierro/metabolismo , Macaca fascicularis , Masculino , Ratones , Persona de Mediana Edad , Ratas , Insuficiencia Renal Crónica/sangre , Insuficiencia Renal Crónica/metabolismo , Resultado del Tratamiento , Adulto JovenRESUMEN
Aplysin, a kind of phytochemicals or phytonutrients, is purified from red alga Laurencia tristicha. The present study aims to investigate the influence of aplysin on changes of intestinal permeability and microbiota induced by excessive ethanol and iron. Thirty male rats were randomly divided into three groups (10/group): control group (normal saline); ethanol + iron group as EI treated with ethanol (8â»12 mL/kg/day) and iron (1000 mg/kg) in diet; EI supplemented with aplysin (150 mg/kg/day) group as AEI; the trial lasts for 12 weeks. The result showed that levels of plasma endotoxin, fatty acid-binding protein 2, D-lactic acid, diamine oxidase were increased in rats in the EI group; and significantly decreased by 14%, 17%, 26%, 16%, respectively (p < 0.05) in the AEI group after the 12-week aplysin treatment. Moreover, in the AEI group the amount of Escherichia coli and Bacteroides fragilis were higher, while the amount of Lactobacillus, Bifidobacterium and Clostridium were lower than those in the EI group. The expressions of iron transporters divalent-metal transporter 1(DMT1) and ferroportin 1(FPN1) were significantly upregulated in the EI group compared to those in the control group. In conclusion, aplysin could effectively improve intestinal permeability and intestinal flora disorder induced with excessive ethanol and iron.
Asunto(s)
Suplementos Dietéticos , Disbiosis/prevención & control , Enteritis/prevención & control , Fármacos Gastrointestinales/uso terapéutico , Microbioma Gastrointestinal , Hidrocarburos Bromados/uso terapéutico , Sustancias Protectoras/uso terapéutico , Sesquiterpenos/uso terapéutico , Consumo de Bebidas Alcohólicas/efectos adversos , Animales , Proteínas de Transporte de Catión/agonistas , Proteínas de Transporte de Catión/antagonistas & inhibidores , Proteínas de Transporte de Catión/metabolismo , Disbiosis/etiología , Disbiosis/microbiología , Disbiosis/patología , Enteritis/etiología , Enteritis/microbiología , Enteritis/patología , Mucosa Intestinal/metabolismo , Mucosa Intestinal/microbiología , Mucosa Intestinal/patología , Mucosa Intestinal/ultraestructura , Intestino Delgado/metabolismo , Intestino Delgado/microbiología , Intestino Delgado/patología , Intestino Delgado/ultraestructura , Hierro de la Dieta/envenenamiento , Masculino , Microscopía Electrónica de Transmisión , Estrés Oxidativo , Permeabilidad , Distribución Aleatoria , Ratas WistarRESUMEN
Moringa oleifera leaves are a well-known source of antioxidants and traditionally used for medicinal applications. In the present study, the protective action of soluble M. oleifera leaf extract (MOLE) against cadmium toxicity was investigated in the model eukaryote Saccharomyces cerevisiae. The results showed that this extract exhibited a protective effect against oxidative stress induced by cadmium and H2O2 through the reduction of intracellular reactive oxygen species. Interestingly, not only the co-exposure of soluble MOLE with cadmium but also pretreatment of this extract prior to cadmium exposure significantly reduced the cadmium uptake through an inhibition of Fet4p, a low-affinity iron(II) transporter. In addition, the supplementation of soluble MOLE significantly reduced intracellular iron accumulation in a Fet4p-independent manner. Our findings suggest the potential use of soluble extract from M. oleifera leaves as a dietary supplement for protection against cadmium accumulation and oxidative stress.
Asunto(s)
Cadmio/metabolismo , Moringa oleifera/química , Estrés Oxidativo/efectos de los fármacos , Extractos Vegetales/farmacología , Hojas de la Planta/química , Saccharomyces cerevisiae/efectos de los fármacos , Saccharomyces cerevisiae/metabolismo , Antioxidantes/farmacología , Transporte Biológico/efectos de los fármacos , Proteínas de Transporte de Catión/antagonistas & inhibidores , Proteínas de Transporte de Catión/metabolismo , Proteínas Transportadoras de Cobre , Suplementos Dietéticos , Peróxido de Hidrógeno/farmacología , Hierro/metabolismo , Proteínas de Unión a Hierro/antagonistas & inhibidores , Proteínas de Unión a Hierro/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Saccharomyces cerevisiae/citología , Proteínas de Saccharomyces cerevisiae/antagonistas & inhibidores , Proteínas de Saccharomyces cerevisiae/metabolismo , SolubilidadRESUMEN
Disturbed magnesium (Mg(2+)) homoeostasis and increased levels of OS (oxidative stress) are associated with poor clinical outcomes in patients suffering from neurodegenerative, cardiovascular and metabolic diseases. Data from clinical and animal studies suggest that MD (Mg(2+) deficiency) is correlated with increased production of ROS (reactive oxygen species) in cells, but a straightforward causal relationship (including molecular mechanisms) between the two conditions is lacking. The multifactorial protein PARK7/DJ-1 is a major antioxidant protein, playing a key role in cellular redox homoeostasis, and is a positive regulator of AR (androgen receptor)-dependent transcription. SLC41A1 (solute carrier family 41 member 1), the gene encoding a ubiquitous cellular Mg(2+)E (Mg(2+)efflux) system, has been shown to be regulated by activated AR. We hypothesize that overexpression/up-regulation of PARK7/DJ-1, attributable to OS and related activation of AR, is an important event regulating the expression of SLC41A1 and consequently, modulating the Mg(2+)E capacity. This would involve changes in the transcriptional activity of PARK7/DJ-1, AR and SLC41A1, which may serve as biomarkers of intracellular MD and may have clinical relevance. Imipramine, in use as an antidepressant, has been shown to reduce the Mg(2+)E activity of SLC41A1 and OS. We therefore hypothesize further that administration of imipramine or related drugs will be beneficial in MD- and OS-associated diseases, especially when combined with Mg(2+) supplementation. If proved true, the OS-responsive functional axis, PARK7/DJ-1-AR-SLC41A1, may be a putative mechanism underlying intracellular MD secondary to OS caused by pro-oxidative stimuli, including extracellular MD. Furthermore, it will advance our understanding of the link between OS and MD.
Asunto(s)
Enfermedades Cardiovasculares/etiología , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Deficiencia de Magnesio/etiología , Enfermedades Metabólicas/etiología , Enfermedades Neurodegenerativas/etiología , Proteínas Oncogénicas/metabolismo , Estrés Oxidativo , Transducción de Señal , Animales , Enfermedades Cardiovasculares/metabolismo , Enfermedades Cardiovasculares/prevención & control , Proteínas de Transporte de Catión/antagonistas & inhibidores , Proteínas de Transporte de Catión/metabolismo , Enfermedad Crónica , Humanos , Imipramina/uso terapéutico , Deficiencia de Magnesio/tratamiento farmacológico , Deficiencia de Magnesio/metabolismo , Enfermedades Metabólicas/metabolismo , Enfermedades Metabólicas/prevención & control , Terapia Molecular Dirigida , Enfermedades Neurodegenerativas/metabolismo , Enfermedades Neurodegenerativas/prevención & control , Estrés Oxidativo/efectos de los fármacos , Proteína Desglicasa DJ-1 , Receptores Androgénicos/metabolismo , Factores de Riesgo , Regulación hacia ArribaRESUMEN
BACKGROUND: Na(+)/H(+) exchanger-1 (NHE-1) is involved in pH regulation and is up-regulated in different malignancies. Activation of NHE-1 is one way for allowing cells to avoid intracellular acidification and protect them against apoptosis. Inhibitors of NHE-1 are able to decrease intracellular pH and induce apoptosis. Some statins can also act by partial inhibition of NHE-1. This review presents progress in understanding the mechanisms of action of these inhibitors, connections with certain genetic mutations and acquired treatment resistance, as well as new patents on them. METHODS: A MEDLINE search for original and review articles using key terms, Na(+)/H(+) exchanger, leukemia, cariporide, and amiloride. Recent patents with NHE-1 inhibitors published by United States Patent and Trademark Office are also presented. RESULTS AND CONCLUSIONS: Sorafenib is used for the treatment of acute myeloid leukemia patients carrying internal tandem duplication of fms-like tyrosine kinase 3 (FLT3-ITD) mutation. 5-(N, N-hexamethylene)-amiloride can increase the suppression of FLT3 signaling by sorafenib. NHE-1 inhibitors are able to increase the sensitivity of chronic myeloid leukemia cells to tyrosine kinase inhibitors, including through the inhibition of P-glycoprotein. NHE-1 inhibitors are promising adjuvant drugs for overcoming acquired resistance to treatment in various malignant hemopathies.
Asunto(s)
Proteínas de Transporte de Catión/antagonistas & inhibidores , Leucemia Mielógena Crónica BCR-ABL Positiva/tratamiento farmacológico , Leucemia Mieloide Aguda/tratamiento farmacológico , Intercambiadores de Sodio-Hidrógeno/antagonistas & inhibidores , Amilorida/farmacología , Antineoplásicos/farmacología , Apoptosis/efectos de los fármacos , Proteínas de Transporte de Catión/fisiología , Línea Celular Tumoral , Daño del ADN/fisiología , Interacciones Farmacológicas , Genes abl/genética , Guanidinas/farmacología , Hemo-Oxigenasa 1/antagonistas & inhibidores , Hemo-Oxigenasa 1/metabolismo , Humanos , Concentración de Iones de Hidrógeno , Inhibidores de Hidroximetilglutaril-CoA Reductasas/farmacocinética , Mesilato de Imatinib/farmacología , Leucemia Mielógena Crónica BCR-ABL Positiva/genética , Leucemia Mieloide Aguda/genética , Mutación/genética , Niacinamida/análogos & derivados , Niacinamida/farmacología , Concentración Osmolar , Patentes como Asunto , Compuestos de Fenilurea/farmacología , Inhibidores de Proteínas Quinasas/farmacología , Transducción de Señal/efectos de los fármacos , Intercambiador 1 de Sodio-Hidrógeno , Intercambiadores de Sodio-Hidrógeno/fisiología , Sorafenib , Sulfonas/farmacología , Hipoxia Tumoral/fisiología , Regulación hacia Arriba/fisiología , Tirosina Quinasa 3 Similar a fms/antagonistas & inhibidores , Tirosina Quinasa 3 Similar a fms/genéticaRESUMEN
The purpose of the present study was to determine whether copper histidine could inhibit copper transporter 1 (Ctr1)-mediated transport of oxaliplatin in vitro and thereby limit the accumulation of platinum and neurotoxicity of oxaliplatin in dorsal root ganglion (DRG) tissue in vivo. In HEK293 cells overexpressing rat Ctr1, copper histidine was shown to be transported by Ctr1 and to inhibit their Ctr1-mediated uptake of oxaliplatin. Pilot in vivo dose-finding studies showed that copper histidine at doses up to 2 mg/kg, p.o., daily for 5 days/week could be added to maximum tolerated doses of oxaliplatin (1.85 mg/kg, i.p., twice weekly) for 8 week combination treatment studies in female Wistar rats. After treatment, rats showed significant changes in sensory neuron size profiles in DRG tissue induced by oxaliplatin that were not altered by its coadministration with copper histidine. The expression of copper transporters (Ctr1 and copper-transporting P-type ATPase 1 (Atp7a)) in DRG tissue appeared unchanged following treatment with oxaliplatin given alone or with copper histidine. Platinum and copper tissue levels were higher in DRG than in most other tissues, but were unaltered by the addition of copper histidine to oxaliplatin treatment. In conclusion, copper histidine inhibited cellular uptake of oxaliplatin mediated by Ctr1 in vitro without altering the accumulation of platinum or neurotoxicity of oxaliplatin in DRG tissue in vivo at doses tolerated in combination with oxaliplatin treatment.
Asunto(s)
Proteínas de Transporte de Catión/antagonistas & inhibidores , Ganglios Espinales/efectos de los fármacos , Intoxicación del Sistema Nervioso por Metales Pesados/prevención & control , Histidina/análogos & derivados , Compuestos Organometálicos/farmacología , Compuestos Organoplatinos/toxicidad , Platino (Metal)/metabolismo , Adenosina Trifosfatasas/metabolismo , Animales , Peso Corporal/efectos de los fármacos , Proteínas de Transporte de Catión/genética , Proteínas de Transporte de Catión/metabolismo , Cobre/metabolismo , Transportador de Cobre 1 , ATPasas Transportadoras de Cobre , Relación Dosis-Respuesta a Droga , Evaluación Preclínica de Medicamentos , Interacciones Farmacológicas , Femenino , Ganglios Espinales/metabolismo , Ganglios Espinales/patología , Células HEK293 , Intoxicación del Sistema Nervioso por Metales Pesados/patología , Histidina/farmacología , Humanos , Compuestos Organoplatinos/farmacocinética , Oxaliplatino , Ratas , TransfecciónRESUMEN
Inhibition of intestinal brush border DMT1 offers a novel therapeutic approach to the prevention and treatment of disorders of iron overload. Several series of diaryl and tricyclic benzylisothiourea compounds as novel and potent DMT1 inhibitors were discovered from the original hit compound 1. These compounds demonstrated in vitro potency against DMT1, desirable cell permeability properties and a dose-dependent inhibition of iron uptake in an acute rat model of iron hyperabsorption. Tricyclic compounds increased the in vitro potency by up to 16-fold versus the original hit. Diaryl compounds 6b and 14a demonstrated significant iron absorption inhibition in vivo with both 25 and 50 mg/kg doses. The diaryl and tricyclic compounds described in this report represent promising structural templates for further optimization.
Asunto(s)
Proteínas de Transporte de Catión/antagonistas & inhibidores , Tiourea/química , Animales , Células CACO-2 , Proteínas de Transporte de Catión/metabolismo , Permeabilidad de la Membrana Celular/efectos de los fármacos , Modelos Animales de Enfermedad , Evaluación Preclínica de Medicamentos , Humanos , Hierro/metabolismo , Sobrecarga de Hierro/metabolismo , Sobrecarga de Hierro/patología , Ratas , Relación Estructura-Actividad , Tiourea/síntesis química , Tiourea/farmacologíaRESUMEN
Magnesium (Mg(2+)) is the second most abundant cation in cells, yet relatively few mechanisms have been identified that regulate cellular levels of this ion. The most clearly identified Mg(2+) transporters are in bacteria and yeast. Here, we use a yeast complementary screen to identify two mammalian genes, MagT1 and TUSC3, as major mechanisms of Mg(2+) influx. MagT1 is universally expressed in all human tissues and its expression level is up-regulated in low extracellular Mg(2+). Knockdown of either MagT1 or TUSC3 protein significantly lowers the total and free intracellular Mg(2+) concentrations in mammalian cell lines. Morpholino knockdown of MagT1 and TUSC3 protein expression in zebrafish embryos results in early developmental arrest; excess Mg(2+) or supplementation with mammalian mRNAs can rescue the effects. We conclude that MagT1 and TUSC3 are indispensable members of the vertebrate plasma membrane Mg(2+) transport system.
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Proteínas de Transporte de Catión/metabolismo , Desarrollo Embrionario/fisiología , Magnesio/metabolismo , Proteínas de la Membrana/metabolismo , Proteínas Supresoras de Tumor/metabolismo , Animales , Animales Modificados Genéticamente , Secuencia de Bases , Proteínas de Transporte de Catión/antagonistas & inhibidores , Proteínas de Transporte de Catión/química , Proteínas de Transporte de Catión/genética , Línea Celular , Desarrollo Embrionario/genética , Femenino , Prueba de Complementación Genética , Humanos , Transporte Iónico , Células Jurkat , Masculino , Proteínas de la Membrana/antagonistas & inhibidores , Proteínas de la Membrana/genética , Oligodesoxirribonucleótidos Antisentido/genética , Embarazo , Estructura Secundaria de Proteína , ARN Mensajero/genética , ARN Mensajero/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/crecimiento & desarrollo , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Distribución Tisular , Proteínas Supresoras de Tumor/antagonistas & inhibidores , Proteínas Supresoras de Tumor/genética , Pez Cebra/embriología , Pez Cebra/genética , Pez Cebra/metabolismo , Proteínas de Pez Cebra/antagonistas & inhibidores , Proteínas de Pez Cebra/genética , Proteínas de Pez Cebra/metabolismoRESUMEN
BACKGROUND: Metronidazole is an important antimicrobial agent for the therapeutic management of periodontal diseases and dentoalveolar infections. As in other tissues, the metronidazole concentration in gingival crevicular fluid is about equal to the plasma level. Thus, we hypothesized that metronidazole is not actively transported into human gingival fibroblasts. METHODS: Using high performance liquid chromatography, the influences of extracellular metronidazole concentrations, temperature, pH, and inhibitors of transporters on the uptake of metronidazole by cultured human gingival fibroblasts were tested. RESULTS: Metronidazole was taken up rapidly by fibroblasts; the intracellular metronidazole concentration reached the extracellular level in 3 minutes at 37 degrees C and in 2 minutes at 4 degrees C. The uptake of metronidazole by human gingival fibroblasts was not saturable, and the intracellular metronidazole concentrations increased linearly with the extracellular level. Temperature and pH had no significant influence on the uptake of metronidazole by fibroblasts. Probenecid and adenine had no influence on the uptake of metronidazole by fibroblasts. These findings indicate that metronidazole uptake does not involve a transporter. Metronidazole bound rapidly to human gingival fibroblasts, but the cell-associated drug declined progressively until it reached a stable plateau in 15 minutes. CONCLUSIONS: Metronidazole rapidly entered human gingival fibroblasts via simple diffusion. Metronidazole easily reached the minimal inhibitory concentration in fibroblasts and gingiva. Given the fact that intracellular concentrations of metronidazole in other tissues and cells are also close to the plasma level, we speculate that metronidazole enters other tissues and cells via simple diffusion.
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Antiinfecciosos/farmacocinética , Fibroblastos/metabolismo , Encía/metabolismo , Metronidazol/farmacocinética , Adenina/farmacología , Adyuvantes Farmacéuticos/farmacología , Adolescente , Antiinfecciosos/sangre , Proteínas de Transporte de Catión/antagonistas & inhibidores , Células Cultivadas , Cromatografía Líquida de Alta Presión , Difusión , Líquido Extracelular/metabolismo , Encía/citología , Humanos , Concentración de Iones de Hidrógeno , Líquido Intracelular/metabolismo , Masculino , Moduladores del Transporte de Membrana/farmacología , Metronidazol/sangre , Pruebas de Sensibilidad Microbiana , Probenecid/farmacología , Temperatura , Factores de TiempoRESUMEN
Experimental and clinical investigations suggest that blockade of Na(+)/H(+) exchange (NHE) with cariporide provides functional protection during ischemia and reperfusion in mature hearts. The benefit on aged human myocardium is unknown. Therefore, the impact of cardiac aging on cardio-protection by cariporide after prolonged ischemia was studied in isolated myocardium of adult (
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Envejecimiento/fisiología , Cardiotónicos/farmacología , Guanidinas/farmacología , Corazón/efectos de los fármacos , Daño por Reperfusión Miocárdica/fisiopatología , Sulfonas/farmacología , Adulto , Anciano , Anciano de 80 o más Años , Antiarrítmicos/farmacología , Proteínas de Transporte de Catión/antagonistas & inhibidores , Proteínas de Transporte de Catión/metabolismo , Evaluación Preclínica de Medicamentos/métodos , Corazón/fisiopatología , Atrios Cardíacos/efectos de los fármacos , Atrios Cardíacos/fisiopatología , Humanos , Precondicionamiento Isquémico Miocárdico , Persona de Mediana Edad , Contracción Miocárdica/efectos de los fármacos , Técnicas de Cultivo de Órganos , Intercambiador 1 de Sodio-Hidrógeno , Intercambiadores de Sodio-Hidrógeno/antagonistas & inhibidores , Intercambiadores de Sodio-Hidrógeno/metabolismoRESUMEN
The objective of this study was to investigate the effect of ATP7B antisense oligodeoxynucleotides (ASODNs) on regulating the sensitivity to cisplatin in ovarian carcinoma cell line SKOV3ip1. The ATP7B ASODNs and the corresponding sense oligodeoxynucleotide (SODN) as control were transfected into SKOV3ip1 cells by lipofectamine-2000. The changes of ATP7B were detected by reverse transcription-polymerase chain reaction, flow cytometry, and Western blotting. The survival rate of the SKOV3ip1 cells was assessed by MTT assay. Compared with nontransfected cell, the transfer of ASODN/lipofectin (LF) into SKOV3ip1 cells resulted in (1) 73.70% and 48.30% reduction of ATP7B in messenger RNA and protein, respectively, (2) an obviously decreased intracellular fluorescence intensity from 79.42 to 50.87 (P < 0.01), and (3) a decreased IC(50) value for cisplatin from 126.63 to 80.90 micromol/L (P < 0.01), while no significant changes were detected for groups treated with SODN/LF and LF only. ASODN transfection can inhibit the expression of ATP7B and increase the cisplatin sensitivity in SKOV3ip1 cells.
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Adenosina Trifosfatasas/antagonistas & inhibidores , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Carcinoma/tratamiento farmacológico , Proteínas de Transporte de Catión/antagonistas & inhibidores , Cisplatino/administración & dosificación , Resistencia a Antineoplásicos/efectos de los fármacos , Oligodesoxirribonucleótidos Antisentido/administración & dosificación , Neoplasias Ováricas/tratamiento farmacológico , Adenosina Trifosfatasas/genética , Adenosina Trifosfatasas/metabolismo , Carcinoma/genética , Carcinoma/metabolismo , Carcinoma/patología , Proteínas de Transporte de Catión/genética , Proteínas de Transporte de Catión/metabolismo , Línea Celular Tumoral , ATPasas Transportadoras de Cobre , Evaluación Preclínica de Medicamentos , Resistencia a Antineoplásicos/genética , Sinergismo Farmacológico , Femenino , Regulación Neoplásica de la Expresión Génica , Humanos , Neoplasias Ováricas/genética , Neoplasias Ováricas/metabolismo , Neoplasias Ováricas/patología , ARN Mensajero/metabolismo , TransfecciónRESUMEN
HEK293T cells overexpressing divalent metal transporter-1 (DMT1) were established to screen for small-molecule inhibitors of iron uptake. Using a fluorescence-based assay, we tested 2000 known bioactive compounds to find 3 small molecules that potently block ferrous iron uptake. One of the inhibitors, ebselen, is a seleno compound used in clinical trials as a protective agent against ischemic stroke. Ebselen inhibited Fe(II) uptake (IC(50) of approximately 0.22 microM), but did not influence Fe(III) transport or DMT1-mediated manganese uptake. An unrelated antioxidant, pyrrolidine dithiobarbamate (PDTC), also inhibited DMT1 activity (IC(50) of approximately 1.54 microM). Both ebselen and PDTC increased cellular levels of reduced glutathione. These observations indicate that Fe(II) transport by DMT1 can be modulated by cellular redox status and suggest that ebselen may act therapeutically to limit iron-catalyzed damage due to transport inhibition.
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Antioxidantes/farmacología , Azoles/farmacología , Proteínas de Transporte de Catión/antagonistas & inhibidores , Proteínas de Transporte de Catión/metabolismo , Compuestos Ferrosos/metabolismo , Compuestos de Organoselenio/farmacología , Antioxidantes/farmacocinética , Azoles/farmacocinética , Línea Celular , Relación Dosis-Respuesta a Droga , Evaluación Preclínica de Medicamentos , Compuestos Férricos/metabolismo , Fluoresceínas/metabolismo , Humanos , Concentración 50 Inhibidora , Transporte Iónico/efectos de los fármacos , Isoindoles , Manganeso/metabolismo , Compuestos de Organoselenio/farmacocinética , Prolina/análogos & derivados , Prolina/farmacología , Tiocarbamatos/farmacología , TransfecciónRESUMEN
Unintended inhibition of the cardiac potassium channel human ether-a-go-go-related gene (hERG) is considered the main culprit in drug-induced arrhythmias known as torsades de pointes. Electrophysiology is the most reliable in vitro screening method for identifying potential cardiac hERG liabilities, but only the recent advent of planar electrode-based voltage clamp electrophysiology promises sufficient throughput to support the drug testing needs of most drug discovery programs. We have assessed the reliability of this new format of the voltage clamp technology in measuring the activity of small molecules on the hERG channel. Based on the results herein of a screening against a panel of well-characterized hERG-active and -inactive molecules, we demonstrate that planar electrode electrophysiology, utilizing the Sealchip and PatchXpress technology platform (AVIVA Biosciences Corp., San Diego, CA), is comparable to traditional electrophysiology based on glass micropipettes in its reliability and data content. The new technology will allow significantly higher throughput and more thorough testing of pharmaceutical compounds.