RESUMEN
BACKGROUND: Postherpetic pain (PHP) is difficult to control. Although Neurotropin® (NTP) and methylcobalamin (MCB) are often prescribed to treat the pain, the efficacy of combined treatment for PHP remains imcompletely understood. OBJECTIVE: In this study, we investigate the combined effects of NTP and MCB on PHP in mice. METHODS: NTP and MCB were administered from day 10-29 after herpes simplex virus type-1 (HSV-1) infection. The pain-related responses were evaluated using a paint brush. The expression of neuropathy-related factor (ATF3) and nerve repair factors (GAP-43 and SPRR1A) in the dorsal root ganglion (DRG) and neurons in the skin were evaluated by immunohistochemical staining. Nerve growth factor (NGF) and neurotrophin-3 (NT3) mRNA expression levels were evaluated using real-time PCR. RESULTS: Repeated treatment with NTP and MCB after the acute phase inhibited PHP. Combined treatment with these drugs inhibited PHP at an earlier stage than either treatment alone. In the DRG of HSV-1-infected mice, MCB, but not NTP, decreased the number of cells expressing ATF3 and increased the number of cells expressing GAP-43- and SPRR1A. In addition, MCB, but not NTP, also increased and recovered non-myelinated neurons decreased in the lesional skin. NTP increased the mRNA levels of NTF3 in keratinocytes, while MCB increased that of NGF in Schwann cells. CONCLUSION: These results suggest that combined treatment with NTP and MCB is useful for the treatment of PHP. The combined effect may be attributed to the different analgesic mechanisms of these drugs.
Asunto(s)
Herpes Simple , Herpesvirus Humano 1 , Neuralgia Posherpética , Polisacáridos , Vitamina B 12/análogos & derivados , Ratones , Animales , Neuralgia Posherpética/tratamiento farmacológico , Factor de Crecimiento Nervioso/metabolismo , Proteína GAP-43/farmacología , Herpes Simple/complicaciones , Herpes Simple/tratamiento farmacológico , ARN MensajeroRESUMEN
We have recently found that combination of ovariectomy (OVX) and chronic restraint stress causes cognitive dysfunction and reduces hippocampal CA3 neurons in female rats and mice and that estrogen replacement and chronic treatment with Ginkgo biloba extract EGb 761 suppress the OVX/stress-induced behavioral and morphological changes. In this study, we examined the effect of placental extract on the memory impairment and neuromorphological change in OVX/stress-subjected mice. Female Slc:ICR strain mice were randomly divided into four groups: vehicle-treated OVX, porcine placental extract (120 and 2160 mg/kg)-treated OVX, and sham-operated control groups. Two weeks after surgical operation, OVX mice underwent restraint stress for 21 days (6 h/day), and all animals were then subjected to a contextual fear conditioning test followed by morphological examination by Nissl staining. Placental extract was orally administered once daily until the behavioral analysis was carried out. Chronic treatment with both doses of placental extract improved the OVX/stress-induced fear memory impairment and Nissl-positive cell loss of the hippocampal CA3 region, although it did not affect the loss of bone mineral density and increase in body weight after OVX. These results have important implications for the neuroprotective and cognition-enhancing effects of placental extract in postmenopausal women.
Asunto(s)
Miedo , Ginkgo biloba/química , Hipocampo/efectos de los fármacos , Inmovilización , Trastornos de la Memoria/patología , Neuronas/patología , Ovariectomía , Placenta/química , Extractos Vegetales/farmacología , Estrés Fisiológico , Animales , Densidad Ósea/efectos de los fármacos , Femenino , Hipocampo/patología , Ratones , Ratones Endogámicos ICR , Tamaño de los Órganos/efectos de los fármacos , Embarazo , Ratas , Útero/efectos de los fármacosRESUMEN
OBJECTIVE: A previous open study demonstrated that French maritime pine bark extract (Pycnogenol) may soothe menstrual pain in dysmenorrhea. We thus investigated the effects of Pycnogenol on menstrual pain in a double-blind study. STUDY DESIGN: Subjects were 116 women aged 18-48 years. The first 2 menstrual cycles served as a control period; during the subsequent 2 menstrual cycles women received either a Pycnogenol supplement (60 mg/day) or a placebo in identical capsule form. One further cycle was monitored after cessation of capsule administration. Women were assigned to either a group with low menstrual pain or a group with dysmenorrhea. The criterion for assignment to the first group was absence of analgesic medication. RESULTS: In women with low menstrual pain, no significant difference for lowering of pain scores was found. In contrast, women with dysmenorrhea had a significantly lower pain score and required statistically significantly less analgesic medication during supplementation with Pycnogenol. The number of days women required analgesic medication was likewise found to be statistically significantly lowered in the Pycnogenol group. Even after discontinuation of Pycnogenol supplementation, the required analgesic medication remained significantly decreased. CONCLUSION: The analgesic-sparing effect of Pycnogenol increases with duration of supplementation and benefits persist even after discontinuation.
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Analgésicos/administración & dosificación , Dismenorrea/tratamiento farmacológico , Flavonoides/uso terapéutico , Inhibidores de Agregación Plaquetaria/uso terapéutico , Adolescente , Adulto , Método Doble Ciego , Femenino , Humanos , Japón , Persona de Mediana Edad , Dimensión del Dolor , Extractos Vegetales , Calidad de Vida , Resultado del TratamientoRESUMEN
Ovarian hormone decline after menopause may influence cognitive performance and increase the risk for Alzheimer's disease (AD) in women. Amyloid-beta peptide (Abeta) has been proposed to be the primary cause of AD. In this study, we examined whether ovariectomy (OVX) could affect the levels of cofactors Abeta-binding alcohol dehydrogenase (ABAD) and receptor for advanced glycation endproducts (RAGE), which have been reported to potentiate Abeta-mediated neuronal perturbation, in mouse hippocampus, correlating with estrogen and Abeta levels. Female ICR mice were randomly divided into ovariectomized or sham-operated groups, and biochemical analyses were carried out at 5 weeks after the operation. OVX for 5 weeks significantly decreased hippocampal 17beta-estradiol level, while it tended to reduce the hormone level in serum, compared with the sham-operated control. In contrast, OVX did not affect hippocampal Abeta(1-40) level, although it significantly increased serum Abeta(1-40) level. Furthermore, we demonstrated that OVX increased hippocampal ABAD level in neurons, but not astrocytes, while it did not affect RAGE level. These findings suggest that the expression of neuronal ABAD depends on estrogen level in the hippocampus and the increase in serum Abeta and hippocampal ABAD induced by ovarian hormone decline may be associated with pre-stage of memory deficit in postmenopausal women and Abeta-mediated AD pathology.
Asunto(s)
Alcohol Deshidrogenasa/metabolismo , Péptidos beta-Amiloides/metabolismo , Hipocampo/metabolismo , Neuronas/metabolismo , Ovariectomía , Animales , Astrocitos/metabolismo , Western Blotting , Proteínas de Unión al ADN , Estradiol/farmacología , Femenino , Proteína Ácida Fibrilar de la Glía/metabolismo , Hipocampo/citología , Hipocampo/enzimología , Ratones , Ratones Endogámicos ICR , Proteínas del Tejido Nervioso/metabolismo , Proteínas Nucleares/metabolismo , Receptor para Productos Finales de Glicación Avanzada , Receptores Inmunológicos/metabolismoRESUMEN
Ovarian hormone decline after menopause may influence cognitive performance and increase the risk for Alzheimer's disease (AD) in women. We have recently demonstrated that a combination of ovariectomy and chronic stress (OVX/stress) causes hippocampus-associated cognitive dysfunction in mice. In this study, we examined whether OVX/stress could affect the levels of AD-related molecules in the mouse hippocampus. Female ICR mice were ovariectomized or sham-operated, and then randomly divided into a daily restraint stress (21 days, 6 h/day) or non-stress group. Although OVX or stress alone did not affect beta-site amyloid precursor protein (APP)-cleaving enzyme-1 (BACE1) activity, OVX/stress increased activity in hippocampal CA1 and CA3 regions, compared with other groups. In contrast, OVX/stress did not affect gamma-secretase activity, Abeta(1-40), and phosphorylated-tau levels in the hippocampus. These findings suggest that a stressful life after menopause can influence the levels of AD-related molecules and that BACE1 is the most sensitive molecule for such a situation.
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Secretasas de la Proteína Precursora del Amiloide/metabolismo , Ácido Aspártico Endopeptidasas/metabolismo , Regulación de la Expresión Génica/fisiología , Hipocampo/metabolismo , Trastornos de la Memoria/patología , Posmenopausia , Análisis de Varianza , Animales , Modelos Animales de Enfermedad , Ensayo de Inmunoadsorción Enzimática/métodos , Femenino , Trastornos de la Memoria/etiología , Ratones , Ratones Endogámicos ICR , Ovariectomía/métodos , Restricción Física/métodos , Estrés Psicológico/complicaciones , Estrés Psicológico/patología , Factores de TiempoAsunto(s)
Hormona Liberadora de Gonadotropina/fisiología , Gonadotropinas Hipofisarias/metabolismo , Femenino , Gonadotropinas Hipofisarias/biosíntesis , Humanos , Hipotálamo/fisiología , Neuronas/fisiología , Comunicación Paracrina/fisiología , Adenohipófisis/metabolismo , Receptores LHRH/fisiología , Transducción de Señal/fisiología , Factores de Transcripción/fisiología , Factor de Necrosis Tumoral alfa/fisiologíaRESUMEN
This study investigated hearing levels in cases of intractable otitis media with eosinophils and validated the treatment strategy. Medical charts were reviewed retrospectively. The diagnosis was made when the proportion of eosinophils in middle ear secretions exceeded 10%. Twelve patients were identified and treated with an antihistaminergic agent, leukotriene receptor antagonist and topical steroid. The air-bone conductance gap decreased significantly with the relief of subjective symptoms. Bone conduction hearing levels at 4 and 8 kHz were higher than at lower frequencies. There was a significant correlation between subjective symptom duration and bone conduction hearing level at 8 kHz, which diminished with treatment. Compared with suppurative otitis, active otitis with eosinophilia damages high-tone sensory hearing in a time-dependent manner, and antiallergic treatment prevents progression of the high-tone sensory hearing loss. We emphasize the importance of diagnosis and the validity of treatment for intractable otitis media with eosinophils.
Asunto(s)
Eosinofilia/diagnóstico , Eosinofilia/terapia , Otitis Media con Derrame/diagnóstico , Otitis Media con Derrame/terapia , Adulto , Audiometría de Tonos Puros , Conducción Ósea , Enfermedad Crónica , Terapia Combinada , Progresión de la Enfermedad , Femenino , Pérdida Auditiva Sensorineural/prevención & control , Humanos , Masculino , Persona de Mediana Edad , Análisis de Regresión , Estudios Retrospectivos , Estadísticas no ParamétricasRESUMEN
The physiological and pharmacological properties of gamma-aminobutyric acid (GABA)-induced responses were investigated in acutely isolated spiral ganglion cells (SGCs) of guinea pig by using either a nystatin-perforated patch recording configuration or a conventional whole-cell patch recording mode combined with rapid drug application. GABA and GABA(A) subtype receptor agonist, muscimol, induced inward currents in a concentration-dependent manner in 74% of all cells. The current-voltage relationship for the GABA response indicated the GABA-induced current in SGCs is carried by Cl-. Bicuculline (BIC), strychnine (STR), and picrotoxin (PTX) suppressed the GABA response in a concentration-dependent manner. BIC and STR, and PTX blocked the GABA response in a competitive manner and in a non-competitive manner, respectively. For inorganic antagonists, Cd2+ and Ni2+ also inhibited the GABA response. On the other hand, Zn2+ failed to suppress the GABA response in SGCs. An antibiotic, benzylpenicillin, suppressed the GABA response. The GABA response was augmented by both a barbiturate derivative, pentobarbital (PB), and a benzodiazepine derivative, diazepam. The results suggest clearly that the physiological and pharmacological characteristics of GABA(A) receptor on acutely isolated guinea pig SGCs are quite similar to the common GABA(A) receptor found in other sensory ganglion cells.
Asunto(s)
Neuronas/metabolismo , Ganglio Espiral de la Cóclea/metabolismo , Ácido gamma-Aminobutírico/metabolismo , Animales , Células Cultivadas , Femenino , Agonistas del GABA/farmacología , Antagonistas del GABA/farmacología , Cobayas , Masculino , Potenciales de la Membrana/efectos de los fármacos , Potenciales de la Membrana/fisiología , Neuronas/efectos de los fármacos , Técnicas de Placa-Clamp , Receptores de GABA-A/efectos de los fármacos , Receptores de GABA-A/metabolismo , Ganglio Espiral de la Cóclea/citologíaRESUMEN
OBJECTIVE: Bile acid-sequestering resins are known to be potent hypocholesterolaemic drugs, and a feeling of abdominal fullness has been reported as the most frequent adverse effect associated with their use. However, this unique adverse effect of colestilan, abdominal fullness, may have the potential to reduce total food intake. The aim of this study was to investigate the effect of colestilan, a new bile acid-sequestering resin, on the bodyweight of postmenopausal women who had previously dieted unsuccessfully. METHODS: Forty postmenopausal women who failed to diet successfully over a 4-week period were enrolled in this randomised, open-label, controlled study. Subjects were randomised to two groups: the colestilan group received four colestilan tablets administered in divided doses with three glasses of water before dinner and bedtime for 12 weeks; the control group received three glasses of water before dinner and bedtime for 12 weeks. All patients were monitored and were given the same diet instructions. RESULTS: Twelve weeks' administration of colestilan in addition to diet instruction significantly reduced bodyweight and body mass index from 62.9 +/- 5.7kg to 58.0 +/- 5.4kg (mean +/- SD) and from 26.1 +/- 2.0 kg/m2 to 23.9 +/- 2.0 kg/m2, respectively. There were no significant differences in bodyweight before and after 12 weeks of treatment in the control group. CONCLUSION: Colestilan may be useful for appetite control and exerts anti-obesity effects when used in conjunction with a weight-management programme.
Asunto(s)
Depresores del Apetito/uso terapéutico , Ácidos y Sales Biliares/uso terapéutico , Peso Corporal/efectos de los fármacos , Obesidad/tratamiento farmacológico , Posmenopausia/metabolismo , Depresores del Apetito/administración & dosificación , Ácidos y Sales Biliares/administración & dosificación , Ácidos y Sales Biliares/metabolismo , Índice de Masa Corporal , Esquema de Medicación , Ingestión de Alimentos/efectos de los fármacos , Femenino , Humanos , Persona de Mediana Edad , Obesidad/dietoterapia , Resultado del TratamientoRESUMEN
Overexpression of cyclin D1 in head and neck cancer has been suggested to be a poor prognostic factor. To understand the role of cyclin D1 expression in head and neck cancer, we overexpressed cyclin D1 in TU182 (a cell line derived from pharyngeal cancer) using a retroviral vector. Stable transfectants were isolated by neomycin (G418) selection. Compared to the parental and control-vector transfected cells, the cyclin D1 transfected cells revealed a decrease of the G1/G0 population and resulted in continuous proliferation under low serum conditions. Proliferation assays revealed an increase in resistance to cisplatin in cyclin D1 overexpressing cells. These observation suggest that deregulation of cyclin D1 may reduce growth factor requirements and contribute to the resistance to some chemotherapeutic agents among head and neck cancer patients.
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Carcinoma de Células Escamosas/metabolismo , Ciclina D1/biosíntesis , Neoplasias de Cabeza y Cuello/metabolismo , Antineoplásicos/farmacología , Northern Blotting , Western Blotting , Carcinoma de Células Escamosas/tratamiento farmacológico , Carcinoma de Células Escamosas/patología , Ciclo Celular/efectos de los fármacos , Línea Celular , Supervivencia Celular/efectos de los fármacos , Cisplatino/farmacología , Ciclina D1/antagonistas & inhibidores , Ciclina D1/genética , Resistencia a Antineoplásicos , Regulación Neoplásica de la Expresión Génica/genética , Neoplasias de Cabeza y Cuello/tratamiento farmacológico , Neoplasias de Cabeza y Cuello/patología , Humanos , Técnicas In Vitro , Pronóstico , Transfección , Células Tumorales CultivadasRESUMEN
BACKGROUND: To clarify the pathophysiological role of tumor-associated macrophages (TAMs), we performed clinicopathological analysis of CD68+ cells in 70 cases of human endometrial cancer. MATERIALS AND METHODS: Using immunohistochemistry for CD68, we classified CD68+ cells into four groups: (a) those infiltrated into cancer cell nests or in close contact with cancer cells (nest TAM); (b) those in necrosis in the tumor center (hot-spot TAM); (c) those infiltrated into cancer stroma (stroma TAM); and (d) those distributed along the invasive margin of a tumor (Margin TAM). RESULTS: The aggregation of nest TAM related to high relapse-free survival rate after surgery. On the contrary, increased hot-spot TAM was a hazard to relapse-free survival and was proportionately-associated with clinical stage, myometrial invasion and histological differentiation. The extent of stroma TAM was associated with the presence of lymph node metastasis. CONCLUSION: Our findings demonstrate that the histological location of infiltrated TAMs may be taken into account in the clinical evaluation of endometrial cancer.
Asunto(s)
Neoplasias Endometriales/inmunología , Neoplasias Endometriales/patología , Macrófagos/inmunología , Macrófagos/patología , Adulto , Anciano , Antígenos CD/biosíntesis , Antígenos CD/inmunología , Antígenos de Diferenciación Mielomonocítica/biosíntesis , Antígenos de Diferenciación Mielomonocítica/inmunología , Femenino , Humanos , Inmunohistoquímica , Macrófagos/clasificación , Persona de Mediana Edad , Estadificación de Neoplasias , PronósticoRESUMEN
The molecular basis of estrogen-mediated neuroprotection against brain ischemia remains obscure. Here, we studied by immunohistochemistry the expression of estrogen receptor (ER) alpha and beta in the hippocampal CA1 sector of postischemic adult macaque monkeys. ERbeta was present in control CA1 pyramidal neurons, decreasing on day 4 after ischemia. In contrast, ERbeta immunoreactivity increased remarkably in the radiate and molecular layers of CA1, where it was present in astrocytes and microglia. ERalpha was negligible in both control and postischemic monkeys. These results indicate that ERbeta is the major receptor responsible for the direct estrogen actions on the monkey hippocampus, regulating glial response after ischemia.
Asunto(s)
Receptor beta de Estrógeno/metabolismo , Hipocampo/metabolismo , Isquemia/metabolismo , Animales , Antígenos CD/metabolismo , Antígenos de Diferenciación Mielomonocítica/metabolismo , Bromodesoxiuridina/metabolismo , Recuento de Células/métodos , Femenino , Proteína Ácida Fibrilar de la Glía/metabolismo , Hipocampo/citología , Inmunohistoquímica/métodos , Macaca , Proteínas Nucleares/metabolismoRESUMEN
OBJECTIVE: Although hormone replacement therapy (HRT) improves menopausal depressive symptoms, women unresponsive to HRT need an antidepressant drug as an effective adjunctive therapy. The aim of this study was to assess whether the herbal medicine Unkei-to has an impact on HRT-resistant menopausal depressive symptoms as an effective adjunctive therapy combined with HRT. METHODS: Twenty-four HRT-resistant menopausal depressive women were randomly assigned to group 1 (n = 12) or group 2 (n = 12). Subjects in group 1 were accessioned into 6 months of open treatment with Unkei-to as an adjunctive therapy and changed to Toki-shakuyaku-san for 6 months following a 1-month washout period. Group 2 started with Toki-shakuyaku-san for 6 months and then changed to Unkei-to for 6 months following a 1-month washout period. RESULTS: Three months' treatment with Unkei-to as an adjunctive therapy significantly improved Zung's Self-Rating Depression Scale (ZSDS) scores, State-Anxiety (STAI-1) scores, and Trait-Anxiety (STAI-2) scores noted before treatment, and this effect continued at 6 months. Treatment with Unkei-to was also significantly effective in reduction of ZSDS scores, STAI-1 scores, and STAI-2 scores at 3 months compared with Toki-shakuyaku-san treatment, and this effect continued at 6 months. CONCLUSIONS: Unkei-to is another option as an adjunctive herbal therapy in HRT-resistant menopausal depressive women.
Asunto(s)
Depresión/tratamiento farmacológico , Medicamentos Herbarios Chinos/uso terapéutico , Terapia de Reemplazo de Estrógeno , Posmenopausia/efectos de los fármacos , Anciano , Cromatografía Líquida de Alta Presión/métodos , Medicamentos Herbarios Chinos/química , Femenino , Humanos , Escala de Ansiedad Manifiesta , Persona de Mediana Edad , Escalas de Valoración Psiquiátrica , Estadísticas no Paramétricas , Factores de Tiempo , Resultado del TratamientoRESUMEN
The effect of Unkei-to, a traditional Japanese herbal medicine and strong in vitro releaser of cytokine-induced neutrophil chemoattractant (CINC), on the increase in locomotor activity induced by intracerebroventricular (icv) injection of corticotropin-releasing factor (CRF) in male rats in a familiar environment was investigated. Oral administration of Unkei-to (100 mg/kg) for 1 week significantly attenuated the CRF-induced increase in locomotor activity. Unkei-to also reduced the CRF-induced accumulation of hypothalamic CINC, which has a functional antagonistic action on the response to CRF; the reduction may reflect an increased release of CINC. These results suggest that Unkei-to has an alleviative effect on the action induced by brain CRF and the mechanism of this effect may partly involve CINC.
Asunto(s)
Hormona Liberadora de Corticotropina/farmacología , Medicamentos Herbarios Chinos/farmacología , Actividad Motora/efectos de los fármacos , Animales , Quimiocinas CXC/metabolismo , Hormona Liberadora de Corticotropina/administración & dosificación , Hipotálamo/efectos de los fármacos , Hipotálamo/metabolismo , Inyecciones Intraventriculares , Péptidos y Proteínas de Señalización Intercelular/metabolismo , Masculino , Ratas , Ratas Sprague-DawleyRESUMEN
Multidrug resistance in human tumour cells is often associated with increased expression of the 190kDa multidrug resistance protein, MRP1, that belongs to the ATP-binding cassette superfamily of transport proteins. MRP1 is also an efficient transporter of many organic anions. In the present study, we have mapped the epitope of the MRP1-specific murine monoclonal antibody (MAb) MRPm5 to the decapeptide (1063)FFERTPSGNL(1072) located in the cytoplasmic loop (CL6) linking transmembrane helices 13 and 14 in the third membrane spanning domain of the protein. Several amino acids in the cytoplasmic loops of MRP1 have been reported to be important for its transport function; nevertheless, MAb MRPm5 does not inhibit vesicular uptake of the high affinity substrate leukotriene C(4). None of the other MRP1-reactive MAbs described to date map to CL6 of MRP1 which in turn enhances the utility of MAb MRPm5 for both clinical and experimental investigations of this transporter.
Asunto(s)
Anticuerpos Monoclonales/inmunología , Proteínas Asociadas a Resistencia a Múltiples Medicamentos/inmunología , Secuencia de Aminoácidos , Sustitución de Aminoácidos , Animales , Anticuerpos Monoclonales/química , Especificidad de Anticuerpos , Línea Celular , Membrana Celular/metabolismo , Citosol/metabolismo , Mapeo Epitopo , Humanos , Leucotrieno C4/metabolismo , Proteínas de la Membrana/química , Ratones , Datos de Secuencia Molecular , Proteínas Asociadas a Resistencia a Múltiples Medicamentos/química , Proteínas Asociadas a Resistencia a Múltiples Medicamentos/genética , Proteínas Asociadas a Resistencia a Múltiples Medicamentos/metabolismo , Oligopéptidos/química , Oligopéptidos/inmunología , Estructura Secundaria de Proteína , Proteínas Recombinantes de Fusión/química , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/inmunología , Proteínas Recombinantes de Fusión/metabolismo , Homología de Secuencia de AminoácidoRESUMEN
Multidrug resistance protein 1 (MRP1/ABCC1) is an ATP-binding cassette transporter that confers resistance to drugs and mediates the transport of organic anions. MRP1 has a core structure of two membrane spanning domains (MSDs) each followed by a nucleotide binding domain. This core structure is preceded by a third MSD with five transmembrane (TM) helices, whereas MSD2 and MSD3 each contain six TM helices. We investigated the consequences of Ala substitution of 18 Pro residues in both the non-membrane and TM regions of MSD2 and MSD3 on MRP1 expression and organic anion transport function. All MRP1-Pro mutants except P1113A were expressed in human embryonic kidney cells at levels comparable with wild-type MRP1. In addition, five mutants containing substitutions of Pro residues in or proximal to the TM helices of MSD2 (TM6-Pro(343), TM8-Pro(448), TM10-Pro(557), and TM11-Pro(595)) and MSD3 (TM14-Pro(1088)) exhibited significantly reduced transport of five organic anion substrates. In contrast, mutation of Pro(1150) in the cytoplasmic loop (CL7) linking TM15 to TM16 caused a substantial increase in 17beta-estradiol-17-beta-(D-glucuronide) and methotrexate transport, whereas transport of other organic anions was reduced or unchanged. Significant substrate-specific changes in the ATP dependence of transport and binding by the P1150A mutant were also observed. Our findings demonstrate the importance of TM6, TM8, TM10, TM11, and TM14 in MRP1 transport function and suggest that CL7 may play a differential role in coupling the activity of the nucleotide binding domains to the translocation of different substrates across the membrane.
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Membrana Celular/metabolismo , Citoplasma/metabolismo , Proteínas Asociadas a Resistencia a Múltiples Medicamentos/química , Prolina/química , Adenosina Trifosfato/química , Alanina/química , Secuencia de Aminoácidos , Aniones , Transporte Biológico , Northern Blotting , Línea Celular , Relación Dosis-Respuesta a Droga , Vectores Genéticos , Humanos , Riñón/embriología , Cinética , Metotrexato/farmacología , Microscopía Confocal , Datos de Secuencia Molecular , Proteínas Asociadas a Resistencia a Múltiples Medicamentos/metabolismo , Mutagénesis Sitio-Dirigida , Mutación , Nucleótidos/química , Unión Proteica , Transporte de Proteínas , Proteínas Ribosómicas , Proteínas de Saccharomyces cerevisiae , Especificidad por Sustrato , Transfección , Vanadatos/farmacologíaRESUMEN
The human ATP-binding cassette (ABC) transporter, multidrug resistance protein 1 (MRP1/ABCC1), confers resistance to a broad range of anti-cancer agents and transports a variety of organic anions. At present, essentially no structural data exists for MRP1 that might be used to elucidate its mechanism of transport. Consequently, we have applied a modeling strategy incorporating crystal and indirect structural data from other ABC transporters to construct a model of the transmembrane domains of the core region of MRP1 that includes the amino acid side chains. Three conserved Trp residues and one non-conserved Tyr residue, shown previously to be of functional importance (Koike, K., Oleschuk, C. J., Haimeur, A., Olsen, S. L., Deeley, R. G., and Cole, S. P. C. (2002) J. Biol. Chem. 277, 49495-49503), were found to line the "pore" in our model proximal to the membrane cytosol interface. A fifth aromatic residue (Phe594) was identified that, with the Trp and Tyr residues, completed a ring or "basket" of aromatic amino acids and, accordingly, we postulated that it would also be of functional importance. To test this idea, MRP1-Phe594 mutants were expressed in human embryonic kidney cells, and their properties were examined using membrane vesicles. Substitution of Phe594 with Ala substantially reduced or eliminated the transport of five organic anion substrates by MRP1 and abrogated the binding of leukotriene C4. On the other hand, the conservatively substituted F594W and F594Y mutants remained transport competent, although significant substrate- and substitution-specific changes were observed. These studies provide some structural insight into a possible substrate binding/transport site of MRP1 at the beginning of a putative substrate translocation pathway and demonstrate the usefulness of modeling for directing structure-function analyses of this transporter.
Asunto(s)
Proteínas Asociadas a Resistencia a Múltiples Medicamentos/química , Fenilalanina , Marcadores de Afinidad , Secuencia de Aminoácidos , Sustitución de Aminoácidos , Secuencia de Bases , Secuencia Conservada , Cartilla de ADN , Humanos , Leucotrieno C4 , Modelos Moleculares , Mutagénesis Sitio-Dirigida , Fenilalanina/química , Conformación Proteica , Estructura Secundaria de Proteína , Transporte de Proteínas , Proteínas Recombinantes/químicaRESUMEN
ELR(+) CXC chemokines including IL-8 are known to be involved in the ischemia-reperfusion injuries in various organs including rodent brain. However, the roles of these chemokines during the ischemia-reperfusion injuries of the primate brain still remain unknown. Here, we studied expressions of CXC chemokines and their receptor CXCR2 in monkey hippocampus known to develop total CA1 neuronal loss on day 5 after 20-min ischemia and reperfusion. ELR(+) chemokines and their receptor CXCR2 were not detected in the hippocampus of non-ischemic monkeys. On the contrary, at 30-60 min after the start of reperfusion, CD68-positive microglial cells increased significantly in the hippocampal CA1 sector, but there was negligible infiltration of neutrophils. These microglial cells expressed simultaneously growth regulated oncogene (Gro)-alpha and other ELR(+) CXC chemokines. Moreover, CD68-positive microglial cells also expressed the receptor for ELR(+) CXC chemokines. On day 4, capillary endothelial cells were significantly increased in the CA1 sector. Considering that ELR(+) CXC chemokines have potent angiogenic activities, the coordinate expression of ELR(+) CXC chemokines and their receptor CXCR2 in microglial cells may be related not only to the ischemic brain injuries but also to the microglial and capillary proliferation in the monkey hippocampus.
Asunto(s)
Quimiocinas CXC/biosíntesis , Hipocampo/metabolismo , Microglía/metabolismo , Receptores de Interleucina-8B/biosíntesis , Daño por Reperfusión/metabolismo , Animales , Quimiocinas CXC/análisis , Femenino , Hipocampo/química , Macaca mulatta , Masculino , Microglía/química , Receptores de Interleucina-8B/análisisRESUMEN
The multidrug resistance protein, MRP1, is a clinically important ATP-binding cassette transporter in which the three membrane-spanning domains (MSDs), which contain up to 17 transmembrane (TM) helices, and two nucleotide binding domains (NBDs) are configured MSD1-MSD2-NBD1-MSD3-NBD2. In tumor cells, MRP1 confers resistance to a broad spectrum of drugs, but in normal cells, it functions as a primary active transporter of organic anions such as leukotriene C(4) and 17beta-estradiol 17beta-(D-glucuronide). We have previously shown that mutation of TM17-Trp(1246) eliminates 17beta-estradiol 17beta-(D-glucuronide) transport and drug resistance conferred by MRP1 while leaving leukotriene C(4) transport intact. By mutating the 11 remaining Trp residues that are in predicted TM segments of MRP1, we have now determined that five of them are also major determinants of MRP1 function. Ala substitution of three of these residues, Trp(445) (TM8), Trp(553) (TM10), and Trp(1198) (TM16), eliminated or substantially reduced transport levels of five organic anion substrates of MRP1. In contrast, Ala substitutions of Trp(361) (TM7) and Trp(459) (TM9) caused a more moderate and substrate-selective reduction in MRP1 function. More conservative substitutions (Tyr and Phe) of the Trp(445), Trp(553), and Trp(1198) mutants resulted in substrate selective retention of transport in some cases (Trp(445) and Trp(1198)) but not others (Trp(553)). Our findings suggest that the bulky polar aromatic indole side chain of each of these five Trp residues contributes significantly to the transport activity and substrate specificity of MRP1.
Asunto(s)
Triptófano/química , Adenosina Trifosfato/metabolismo , Alanina/química , Algoritmos , Cationes , Línea Celular , Membrana Celular/metabolismo , Vectores Genéticos , Proteínas Fluorescentes Verdes , Humanos , Immunoblotting , Transporte Iónico , Iones , Leucotrieno C4/metabolismo , Proteínas Luminiscentes/metabolismo , Microscopía Confocal , Modelos Biológicos , Mutagénesis Sitio-Dirigida , Mutación , Unión Proteica , Estructura Secundaria de Proteína , Estructura Terciaria de Proteína , Transporte de Proteínas , Proteínas Recombinantes de Fusión/metabolismo , Especificidad por Sustrato , Factores de Tiempo , TransfecciónRESUMEN
Tamoxifen is widely applied as an antiestrogenic agent for adjuvant therapy in the treatment of breast cancer, while its estrogen-agonistic activity occasionally causes proliferative disorders or carcinogenesis at other sites, such as the uterus. We reported that estrogen activates telomerase in breast and endometrial cancer cells. The present study examines the effects of tamoxifen on the gene expression of human telomerase reverse transcriptase (hTERT) in breast and endometrial cancer cells. Tamoxifen inhibited the cell growth of MCF-7 cells, as well as hTERT mRNA expression in the presence of estrogen (E2), antagonizing the E2 effects. In contrast, tamoxifen stimulated the growth of Ishikawa cells and activated hTERT mRNA expression in the absence or presence of E2, exhibiting estrogen-agonistic action. Transient expression assays revealed that these actions of tamoxifen are achieved by transcriptional regulation of the hTERT promoter. An estrogen responsive element (ERE) in the hTERT 5' regulatory region was partly responsible for both the E2-antagonistic and -agonistic actions of tamoxifen. Tamoxifen activated the MAP kinase cascade in Ishikawa cells, but not in MCF-7 cells, and the activation of hTERT mRNA expression was effectively blocked by MEK inhibitor, suggesting that the MAP kinase pathway is involved in the tamoxifen-induced activation of hTERT. These findings indicate that tamoxifen regulates hTERT expression in a cell-type specific manner. Tamoxifen-induced activation of hTERT may be one component of estrogen agonistic function of tamoxifen that is involved in endometrial carcinogenesis induced by this agent.