RESUMEN
Rice bran oil is a byproduct of the milling of rice (Oryza sativa L.). It offers various health benefits and has a beneficial fatty acid composition. To increase the amount of rice bran as a sink for triacylglycerol (TAG), we developed and characterized new breeding materials with giant embryos. To induce mutants, we treated fertilized egg cells of the high-yielding cultivar 'Mizuhochikara' with N-methyl-N-nitrosourea (MNU). By screening M2 seeds, we isolated four giant embryo mutant lines. Genetic analysis revealed that the causative loci in lines MGE12 and MGE13 were allelic to giant embryo (ge) on chromosome 7, and had base changes in the causal gene Os07g0603700. On the other hand, the causative loci in lines MGE8 and MGE14 were not allelic to ge, and both were newly mapped on chromosome 3. The TAG contents of all four mutant lines increased relative to their wild type, 'Mizuhochikara'. MGE13 was agronomically similar to 'Mizuhochikara' and would be useful for breeding for improved oil content.
RESUMEN
Different biomarkers are used to evaluate the severity of atopic dermatitis (AD); however, it remains difficult to determine the severity of localized skin lesions. MIF plays an essential role in the pathophysiology of skin inflammation. To establish whether the MIF level in the stratum corneum (SC) serves as a marker of the severity of AD lesions, we examined the SC MIF (scMIF) levels in AD patients. The SC of the cheek, neck and upper arm skin was collected using tape stripping, and the scMIF levels were measured. Consequently, the scMIF levels were found to be significantly higher in the involved skin lesions than the uninvolved areas within the same patient. Moreover, the scMIF levels were significantly correlated with the severity of local skin lesions. These findings suggest that the scMIF level can be used as an effective marker for evaluating the local severity of AD.
Asunto(s)
Dermatitis Atópica/metabolismo , Oxidorreductasas Intramoleculares/metabolismo , Factores Inhibidores de la Migración de Macrófagos/metabolismo , Adolescente , Adulto , Biomarcadores/sangre , Biomarcadores/metabolismo , Estudios de Casos y Controles , Dermatitis Atópica/sangre , Dermatitis Atópica/patología , Epidermis/metabolismo , Epidermis/patología , Femenino , Humanos , Oxidorreductasas Intramoleculares/sangre , Factores Inhibidores de la Migración de Macrófagos/sangre , Masculino , Persona de Mediana Edad , Adulto JovenRESUMEN
INTRODUCTION: Mandibular growth is believed to be strongly related to mastication. Furthermore, mandibular condylar cartilage is known to be derived from neural crest cells. We examined whether the degree of chewing affects condylar cartilage growth of the mandible. METHODS: Mice were fed diets with varying hardness. Genes specific to neural crest-derived cells were measured by real-time polymerase chain reaction to compare the expression changes between the mandibular and tibia cartilages. The mandibular condylar cartilage was then evaluated histologically, and proliferation was evaluated using proliferating cell nuclear antigen. Immunostaining was conducted for osteopontin, type X collagen, and Musashi1, and real-time polymerase chain reaction was used to assess the expression levels of osteopontin and type X collagen. RESULTS: Markers including P75, Wnt-1, Musashi1, and Nestin were upregulated in the mandibular condylar cartilage as compared with the tibial cartilage. Histologic assessment of the mandibular cartilage showed that the hypertrophic chondrocyte zone was statistically significantly thicker in mice fed a hard diet. Chondrocyte proliferation and Musashi1 expression were lower in mice fed a hard diet. After 4 weeks, numerous osteopontin and type X collagen-positive cells were observed in mice fed a mixed diet. CONCLUSIONS: Mastication affects the balance between differentiation and proliferation in the mandibular condylar cartilage. This phenomenon might be attributed to the presence of neural crest-derived cells.
Asunto(s)
Cartílago Articular/crecimiento & desarrollo , Cóndilo Mandibular/crecimiento & desarrollo , Masticación/genética , Alimentación Animal/clasificación , Animales , Cartílago Articular/anatomía & histología , Diferenciación Celular/genética , Proliferación Celular , Condrocitos/citología , Colágeno Tipo X/análisis , Expresión Génica/genética , Dureza , Masculino , Cóndilo Mandibular/anatomía & histología , Meniscos Tibiales/anatomía & histología , Meniscos Tibiales/crecimiento & desarrollo , Ratones , Proteínas del Tejido Nervioso/análisis , Nestina/análisis , Cresta Neural/citología , Cresta Neural/metabolismo , Osteopontina/análisis , Antígeno Nuclear de Célula en Proliferación/análisis , Proteínas de Unión al ARN/análisis , Distribución Aleatoria , Reacción en Cadena en Tiempo Real de la Polimerasa , Receptores de Factor de Crecimiento Nervioso/análisis , Factores de Tiempo , Regulación hacia Arriba , Proteína Wnt1/análisisRESUMEN
Although novel techniques for avoiding incontinence during robot-assisted radical prostatectomy have been developed, long-term oncological outcomes are unknown. The objective of this study was to determine the long-term oncological outcomes and functional outcomes of novel nerve-sparing robot-assisted radical prostatectomy with endopelvic fascia preservation for a single surgeon. Data from 100 patients who underwent structure-preserving prostatectomies performed by a single surgeon were retrospectively analyzed. The median console time was 123 min. Bilateral nerve-sparing was performed in 43% of patients underwent, and 57% underwent unilateral nerve-sparing surgery. Most patients (96%) reached complete pad-zero urinary continence by one year after surgery. Satisfactory erectile function was achieved in 97% of patients who underwent bilateral nerve-sparing surgery, and 80% of patients who underwent unilateral nerve-sparing surgery. The surgical margin was positive for 25% of patients, and the biochemical recurrence-free rate at 5 years was 77%. The cancer-specific survival rate was 100% during the median follow-up period of 4.5 years. Clavien-Dindo grade III complications occurred in 1% of cases. The outcomes for novel nerve-sparing robot-assisted radical prostatectomy with endopelvic fascia preservation were similar to previously reported oncological outcomes, with satisfactory functional outcomes. This operative method may be useful for patients who are eligible for nerve-sparing surgery.
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Robótica , Cirujanos , Masculino , Humanos , Estudios Retrospectivos , Prostatectomía , FasciaRESUMEN
UV radiation indirectly regulates melanogenesis in melanocytes through a paracrine regulatory mechanism involving keratinocytes. Protease-activated receptor (PAR)-2 activation induces melanosome transfer by increasing phagocytosis of melanosomes by keratinocytes. This study demonstrated that macrophage migration inhibitory factor (MIF) stimulated PAR-2 expression in human keratinocytes. In addition, we showed that MIF stimulated stem cell factor (SCF) release in keratinocytes; however, MIF had no effect on the release of endothelin-1 or prostaglandin E2 in keratinocytes. In addition, MIF had no direct effect on melanin and tyrosinase synthesis in cultured human melanocytes. The effect of MIF on melanogenesis was also examined using a three-dimensional reconstituted human epidermal culture model, which is a novel, commercially available, cultured human epidermis containing functional melanocytes. Migration inhibitory factor induced an increase in melanin content in the epidermis after a 9-day culture period. Moreover, melanin synthesis induced by UV-B stimulation was significantly down-regulated by anti-MIF antibody treatment. An in vivo study showed that the back skin of MIF transgenic mice had a higher melanin content than that of wild-type mice after 12 weeks of UV-B exposure. Therefore, MIF-mediated melanogenesis occurs mainly through the activation of PAR-2 and SCF expression in keratinocytes after exposure to UV-B radiation.
Asunto(s)
Queratinocitos/metabolismo , Factores Inhibidores de la Migración de Macrófagos/farmacología , Melaninas/biosíntesis , Receptor PAR-2/metabolismo , Factor de Células Madre/metabolismo , Rayos Ultravioleta , Animales , Supervivencia Celular/efectos de los fármacos , Supervivencia Celular/efectos de la radiación , Células Cultivadas , Epidermis/efectos de los fármacos , Epidermis/metabolismo , Epidermis/efectos de la radiación , Humanos , Queratinocitos/efectos de los fármacos , Queratinocitos/patología , Queratinocitos/efectos de la radiación , Melanocitos/efectos de los fármacos , Melanocitos/enzimología , Melanocitos/patología , Melanocitos/efectos de la radiación , Ratones , Ratones Transgénicos , Modelos Biológicos , Monofenol Monooxigenasa/metabolismo , Pigmentación de la Piel/efectos de los fármacos , Pigmentación de la Piel/efectos de la radiación , Factores de Tiempo , Técnicas de Cultivo de TejidosRESUMEN
It is well known that mastication has a significant influence on mandibular growth and development, but the mechanism behind this effect has not yet been clarified. Furthermore, no studies have examined the effects of changes in mastication on the three-dimensional (3D) morphometry of the mandible. The aim of the present study was to investigate the influences of changes in mastication on mandibular growth and morphology. Twenty-five 3-week-old (at the time of weaning) imprinting control region mice were randomly divided into three groups: mice fed a hard diet (HD), mice fed a soft diet (SD), and mice alternately fed hard and soft diets (HSDs) every week for 4 weeks. The morphometry of the mandible was analysed using 3D microcomputed tomography (muCT). Statistical analysis was undertaken using a t-test. muCT analysis showed that the condylar width was significantly greater in the HD group than in the SD group after 1 week. After 4 weeks, mandibular length was significantly longer and ramus height was greater in the HSD group than in the other two groups. Bone volume was significantly less in the SD group than in the other two groups after 4 weeks. These findings suggest that changes in mastication markedly affect mandibular condylar cartilage growth and mandibular morphology. It is considered that dietary education at an early age is important in order to prevent disruption of the development of the mandible.
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Adaptación Fisiológica , Mandíbula/crecimiento & desarrollo , Masticación/fisiología , Alimentación Animal , Animales , Impresión Genómica , Dureza , Masculino , Mandíbula/diagnóstico por imagen , Ratones , Ratones Transgénicos , Distribución Aleatoria , Estrés Mecánico , Soporte de Peso , Microtomografía por Rayos XRESUMEN
Rhodopsin is the photosensitive protein, which binds to 11-cis-retinal as its chromophore. In the dark, rhodopsin exists as a stable complex between the opsin moiety and 11-cis-retinal. The absorption of a light photon converts 11-cis-retinal to all-trans-retinal and initiates our vision. As a result, the increase in the rate of dark activation of rhodopsin reduces its photosensitivity resulting in night blindness. The mutations, G90D and T94I are night blindness-causing mutations that exhibit completely different physicochemical characteristics associated with the dark activation of rhodopsin, such as a high rate of thermal isomerization of 11-cis-retinal and a slow pigment regeneration. To elucidate the molecular mechanism by which G90D and T94I mutations affect rhodopsin dark activation and regeneration, we performed light-induced difference FTIR spectroscopy on dark and primary photo-intermediate states of G90D and T94I mutants. The FTIR spectra clearly show that both charged G90D and hydrophobic T94I mutants alter the H-bond network at the Schiff base region of the chromophore, which weakens the electrostatic interaction with Glu113 counterion. Our results further show an altered water-mediated H-bond network around the central transmembrane region of mutant rhodopsin, which is reminiscent of the active Meta-II state. This altered water-mediated H-bond network may cause thermal isomerization of the chromophore and facilitate rhodopsin dark activation.
Asunto(s)
Ceguera Nocturna/genética , Rodopsina/genética , Animales , Bovinos , Enlace de Hidrógeno , Isomerismo , Modelos Moleculares , Ceguera Nocturna/metabolismo , Mutación Puntual , Conformación Proteica , Retinaldehído/química , Retinaldehído/genética , Retinaldehído/metabolismo , Rodopsina/química , Rodopsina/metabolismoRESUMEN
Mandibular condylar cartilage can be distinguished from articular and growth cartilages of long bones based on several differences in morphology, physiology, and function between these structures. However, there is almost no information available on the types of genes that contribute to these differences. In this study, genes that were differentially expressed in mandibular condylar and growth cartilages in 1-week-old rats were investigated using fluorescent differential display (FDD) and laser microdissection (LMD). A number of genes were identified by FDD including chondromodulin-1 (ChM-1), which is known to be an angiogenesis inhibitor of endochondral ossification. ChM-1 expression was then compared with that of tenomodulin (TeM) in mandibular condylar and tibial cartilages of 1- and 5-week-old rats using real time PCR (RT-PCR), immunohistochemistry, and in situ hybridization. There was negligible detection of ChM-1 mRNA and protein in mandibular condylar cartilages compared to tibial cartilages of 1- and 5-week-old rats. On the other hand, TeM mRNA was more abundant in mandibular condylar cartilage than in tibial. These observations demonstrated that gene expression in mandibular condylar cartilage differed from other types of cartilage such as articular and growth ones.
Asunto(s)
Cartílago Articular/fisiología , Regulación de la Expresión Génica , Péptidos y Proteínas de Señalización Intercelular/metabolismo , Cóndilo Mandibular/anatomía & histología , Proteínas de la Membrana/metabolismo , Tibia/anatomía & histología , Animales , Cartílago Articular/anatomía & histología , Perfilación de la Expresión Génica , Hibridación in Situ , Péptidos y Proteínas de Señalización Intercelular/genética , Rayos Láser , Masculino , Cóndilo Mandibular/fisiología , Proteínas de la Membrana/genética , Microdisección/métodos , Ratas , Ratas Sprague-Dawley , Tibia/fisiologíaRESUMEN
Despite the increasing attention being paid to the functions of glycoproteins, their structural analysis is still difficult and hinders functional investigations. Structural analysis of post-translationally modified proteins is thought to be achieved using methods frequently utilized in proteomics research; however, the same methods cannot be used for glycosylated proteins. One of the difficulties associated with the physiochemical properties of glycopeptides and peptides is that the detection of the former is considerably more difficult, because of the existence of glycoforms that increase molecular weight and reduces quantities of individual species. Thus, difficulties are often faced in finding glycopeptide(s) by using MS when analyzing peaks (or fractions) obtained after proteolytic digestion and HPLC. One simple yet difficult solution to this problem would be to develop a purification method that provides better resolution. Our intention has been to address this issue by using a combination of conventional methods. We found that a method consisting of a combination of rough fractionation using a reverse-phase cartridge column under acidic conditions and comparative RP-HPLC, where the two chromatograms obtained using phosphate and borate buffers under basic conditions were compared, is effective for MS-based structural analysis. The applicability of the method in glycoprotein analysis was examined using various samples including ribonuclease B (RNase B), IgG1, ovalbumin (OVA), and asialo fetuin (ASF). The results suggest that the method is useful in the analysis of glycoproteins.
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Cromatografía Líquida de Alta Presión/instrumentación , Cromatografía Líquida de Alta Presión/métodos , Glicopéptidos/análisis , Glicopéptidos/química , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/instrumentación , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/métodos , Ácidos/química , Álcalis/química , Secuencia de Aminoácidos , Asialoglicoproteínas/química , Asialoglicoproteínas/metabolismo , Boratos , Tampones (Química) , Fetuínas , Humanos , Concentración de Iones de Hidrógeno , Interacciones Hidrofóbicas e Hidrofílicas , Inmunoglobulina G/química , Inmunoglobulina G/inmunología , Datos de Secuencia Molecular , Ovalbúmina/química , Ovalbúmina/metabolismo , Fosfatos , Ribonucleasas/química , Ribonucleasas/metabolismo , Factores de Tiempo , Tripsina/metabolismo , alfa-Fetoproteínas/química , alfa-Fetoproteínas/metabolismoRESUMEN
Gene regulatory networks elucidated from strategic, genome-wide experimental data can aid in the discovery of novel gene function information and expression regulation events from observation of transcriptional regulation among genes of known and unknown biological function. To create a reliable and comprehensive data set for the elucidation of transcription regulation networks, we conducted systematic genome-wide disruption expression experiments of yeast on 118 genes with known involvement in transcription regulation. We report several novel regulatory relationships between known transcription factors and other genes with previously unknown biological function discovered with this expression library. Here we report the downstream regulatory subnetworks for UME6 and MET28. The elucidated network topology among these genes demonstrates MET28's role as a nodal point between genes involved in cell division and those involved in DNA repair mechanisms.
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Genes Reguladores , Biblioteca Genómica , Transcripción Genética , Algoritmos , Análisis de Secuencia por Matrices de OligonucleótidosRESUMEN
BACKGROUND: In the clinical field of jawbone formation, the use of autogenous bone as the graft material is the gold standard. However, there are some problems with this technique, such as risk of infection on the donor side, the limited amount of available bone mass, and marked resorption of the grafted bone. We investigated the potential for using teeth as a bone graft material for jawbone formation because the dental pulp contains stem cells, including undifferentiated neural crest-derived cells. METHODS: Alveolar bone defects were created in Wistar rats, and the defects were filled with either tooth or iliac bone graft material, or left as controls. The potential for using teeth as a bone graft material for jawbone formation was measured using real-time polymerase chain reaction, microcomputed tomography, and histologic analysis. RESULTS: Polymerase chain reaction revealed that the expressions of P75, P0, nestin, and musashi-1 were significantly higher in teeth than in mandibular bone and iliac bone grafts. Hematoxylin and eosin staining and microcomputed tomography showed that at 8 weeks, tooth graft material produced a similar amount of new bone compared to iliac bone graft material. Osteopontin was expressed in both the tooth and iliac bone graft material at 6 and 8 weeks after surgery. Dentin sialoprotein was expressed in the tooth graft material in the new bone at 6 weeks only. CONCLUSION: These results indicate that teeth may be an alternative material to autogenous bone for treating alveolar bone defects by grafting.
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Pérdida de Hueso Alveolar/cirugía , Regeneración Tisular Guiada Periodontal/métodos , Diente/trasplante , Animales , Regeneración Ósea , Sustitutos de Huesos , Trasplante Óseo , Huesos/metabolismo , Proteínas de la Matriz Extracelular/biosíntesis , Masculino , Mandíbula/cirugía , Proteínas del Tejido Nervioso/biosíntesis , Osteopontina/biosíntesis , Fosfoproteínas/biosíntesis , Ratas , Ratas Wistar , Sialoglicoproteínas/biosíntesis , Diente/metabolismoRESUMEN
A 4-week repeated dose oral toxicity study of phenobarbital (PB) sodium was conducted in F344 rats of both sexes at PB doses of 0.8, 8, and 80 mg/kg/day to fully elucidate its general toxicity including hematological changes. Both sexes in the 80 mg/kg/day group showed staggering gait, lacrimation, and/or sedation, which were more evident in the early stage of treatment. The body weight gain and food consumption were greater in these animals than in controls. Hematology revealed a significant reduction in the hematocrit (Ht), hemoglobin concentration (Hb), and erythrocyte count (RBC) in both sexes at 80 mg/kg/day, which was accompanied by a decrease in the cell mean Hb (CHCM) in mature erythrocytes with an increase in unsaturated iron binding capacity. Female rats also showed reduction in the CHCM in reticulocytes, content of hemoglobin per reticulocyte, and transferrin saturation. PB prolonged the activated partial thromboplastin time and inversely increased the platelet count with no evidence of platelet activation. Well-known toxic effects of PB on the liver and thyroid were observed in a dose-dependent manner, along with altered lipid, glucose, and electrolyte metabolism. The serum levels of PB increased dose-dependently, when examined in females received 8 and 80 mg/kg/day on day 1 and 28; there were no difference in C(max) and AUC(0-24) values between day 1 and day 28. These results indicated that PB has the potential to elicit multiple organ toxicity including an effect on the hematopoietic system. The hematological analysis provided evidence for hypochromic anemia, plausibly caused by the impairment of iron utility.
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Anemia Hipocrómica/inducido químicamente , Fenobarbital/toxicidad , Administración Oral , Animales , Peso Corporal/efectos de los fármacos , Ingestión de Alimentos/efectos de los fármacos , Femenino , Marcha/efectos de los fármacos , Hierro/metabolismo , Hígado/efectos de los fármacos , Hígado/metabolismo , Masculino , Tamaño de los Órganos/efectos de los fármacos , Fenobarbital/administración & dosificación , Fenobarbital/farmacocinética , Ratas , Ratas Endogámicas F344 , Pruebas de Toxicidad , UrinálisisRESUMEN
Derivatives of bufogenin isolated from the skin of the Chinese toad, Bufo bufo gargarizans Cantor ("Ch'an Su"), and several semisynthetic derivatives of 20beta,21beta-epoxy-resibufogenin (13) have been evaluated for interleukin-6 (IL-6) antagonistic activity due to their growth-inhibitory activities on IL-6-dependent MH-60 cells. Among the naturally derived compounds (1-17), 20S,21-epoxy-resibufogenin formate (1) showed potent inhibitory activity on the IL-6-dependent growth of MH-60 cells. Epoxide groups at both the C-14, C-15 and C-20, C-21 positions are required to exhibit this type of activity. Compounds acetylated at the C-16 position (7 and 9-11) showed a loss of activity. An oxo group at the C-3 position (8, 14, and 15) resulted in cytotoxicity for both cell lines. Stereochemistry is important for selectivity on suppression of IL-6 activity. Among the semisynthetic derivatives (18-25) of 13, compound 19, with an acetyl group introduced at the C-3 position in comparison to 13, demonstrated considerable growth inhibition of IL-6-dependent MH-60 cells.
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Bufanólidos , Interleucina-6/antagonistas & inhibidores , Animales , Bufanólidos/química , Bufanólidos/aislamiento & purificación , Bufanólidos/farmacología , Bufo bufo , Relación Dosis-Respuesta a Droga , Ensayos de Selección de Medicamentos Antitumorales , Ratones , Estructura Molecular , Estereoisomerismo , Células Tumorales CultivadasRESUMEN
While screening for novel IL-6 inhibitors, we synthesized 20S,21-epoxy-resibufogenin-3-acetate (ERBA). ERBA dose-dependently suppressed IL-6-induced cell growth with an IC(50) value of 5.3 microM and caused a parallel rightward shift of dose-response curves to IL-6. Analysis of data yields a pA2 of 5.83 and a slope of 0.99. ERBA did not affect IL-2-, IL-3-, and GCSF-dependent cell growth, or tumor necrosis factor alpha-induced growth suppression, nor did ERBA affect osteoclast formation induced by IL-11, leukemia inhibitory factor, and 1alpha,25-dihydroxyvitamin D(3). Receptor assay showed that ERBA dose-dependently suppressed IL-6 binding to IL-6 receptor (IL-6R). Furthermore, no band existing at the position of IL-6R in Western blots of ERBA-treated cells when stimulated with IL-6:ERBA suppresses IL-6 activity by blocking the binding of IL-6 to IL-6R. In an experimental model of colon 26-induced cancer cachexia, ERBA markedly inhibited body weight loss. ERBA is a specific small molecule with IL-6R-antagonist activity.
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Células de la Médula Ósea/metabolismo , Bufanólidos/administración & dosificación , Caquexia/tratamiento farmacológico , Neoplasias del Colon/tratamiento farmacológico , Receptores de Interleucina-6/antagonistas & inhibidores , Receptores de Interleucina-6/metabolismo , Cráneo/metabolismo , Animales , Antineoplásicos/administración & dosificación , Peso Corporal/efectos de los fármacos , Células de la Médula Ósea/citología , Células de la Médula Ósea/efectos de los fármacos , Caquexia/etiología , Caquexia/patología , Línea Celular , Línea Celular Tumoral , Técnicas de Cocultivo , Neoplasias del Colon/complicaciones , Neoplasias del Colon/patología , Femenino , Interleucina-6/farmacología , Ratones , Ratones Endogámicos BALB C , Cráneo/citología , Cráneo/efectos de los fármacos , Resultado del TratamientoRESUMEN
IL-6 is a multifunctional cytokine involved in regulation of differentiation, antibody production, and growth of certain types of tumor cells. Its excessive production plays a major role in pathogenesis of multiple myeloma and postmenopausal osteoporosis. In the course of a screening program aimed at IL-6 inhibitor from microbial products, we found madindoline A (MDL-A) and madindoline B, which have a fuloindoline structure with diketocyclopentene bound to the methyl group. MDL-A has no cytotoxic activities. It inhibited only activities of both IL-6 and IL-11 without affecting the IL-6-specific signal transduction cascade, JAK2/STAT3. In a dose-dependent manner [(3)H]MDL-A binds to gp130, which is a signal transducing 130-kDa glycoprotein, but formation of the trimeric complex IL-6/IL-6 receptor/gp130 was not inhibited, suggesting that MDL-A suppresses dimerization of trimeric complexes. Not only did MDL-A markedly inhibit IL-6- and IL-11-induced osteoclastogenesis in vitro, but it also inhibited IL-6-stimulated serum amyloid A production and bone resorption in an experimental model of postmenopausal osteoporosis in vivo by a different mechanism from that of 17beta-estradiol. Here we show that MDL-A has a highly selective inhibitory effect on IL-6 and IL-11 activities by inhibiting a gp130 activity while suppressing bone loss in ovariectomized mice. MDL-A is anticipated as a lead compound for treatment of hormone-dependent postmenopausal osteoporosis, which has no serious side effects, and as a new mechanism of action, gp130 blocking.
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Resorción Ósea/prevención & control , Compuestos Bicíclicos Heterocíclicos con Puentes/farmacología , Citocinas/farmacología , Indoles/farmacología , Receptores de Citocinas/antagonistas & inhibidores , Animales , Línea Celular , Proteínas de Unión al ADN/metabolismo , Femenino , Inhibidores de Crecimiento/farmacología , Humanos , Interleucina-2/farmacología , Interleucina-3/farmacología , Interleucina-4/farmacología , Interleucina-6/farmacología , Interleucina-8 , Factor Inhibidor de Leucemia , Linfocinas/farmacología , Macrófagos/efectos de los fármacos , Macrófagos/fisiología , Ratones , Ratones Endogámicos C3H , Ratones Endogámicos , Factor de Crecimiento Nervioso/farmacología , Proteínas Recombinantes/farmacología , Factor de Transcripción STAT3 , Transducción de Señal/efectos de los fármacos , Transducción de Señal/fisiología , Estereoisomerismo , Transactivadores/metabolismo , Factor de Necrosis Tumoral alfa/farmacologíaRESUMEN
Interleukin (IL)-6 is a key mediator in the regulation and coordination of the immune response and participates in pathogenesis of cancer cachexia, autoimmune disease, and postmenopausal osteoporosis. In the course of a screening program aimed at IL-6 inhibitor from natural products, we isolated 20S,21-epoxy-resibufogenin-3-formate (ERBF) from bufadienolide and examined the effect of ERBF on activities of various cytokines. ERBF dose dependently suppressed IL-6 activity and caused a parallel rightward shift of dose-response curves to IL-6 at concentrations of 0.03 to 10 ng/ml. Analysis of data yields a pA(2) of 5.12 and a slope of 0.99. Selectivity of ERBF on activity of cytokines was examined using cytokine-dependent cell lines. ERBF did not affect IL-2-dependent growth of CTLL-2 cells, IL-3-dependent growth of Baf3 cells, or tumor necrosis factor (TNF)alpha-induced growth suppression in TNFalpha-sensitive L929 cells. ERBF also did not affect IL-4-stimulated expression of FcepsilonR II receptor (CD23) in U-937 cells, the IL-8-induced chemotaxis of human neutrophils, or nerve growth factor-stimulated neuronal differentiation in PC-12 cells. In contrast, ERBF dose dependently suppressed IL-6-induced neuronal differentiation in PC-12 cells. Furthermore, ERBF suppressed only IL-6-induced osteoclast formation without affecting osteoclast formation induced by IL-11, leukemia inhibitory factor, and 1alpha,25-dihydroxyvitamin D(3). In receptor binding assay, unbound (free) IL-6 was increased in a dose-dependent manner by pretreatment with ERBF on IL-6 receptor (IL-6R), suggesting that ERBF suppresses binding of IL-6 to IL-6R. These results clearly indicate that ERBF is a novel specific small molecule to show IL-6 receptor antagonist activity.
Asunto(s)
Bufanólidos/farmacología , Quimiotaxis de Leucocito/efectos de los fármacos , Receptores de Interleucina-6/antagonistas & inhibidores , Animales , Células de la Médula Ósea/citología , Células de la Médula Ósea/efectos de los fármacos , Diferenciación Celular , División Celular/efectos de los fármacos , Línea Celular , Técnicas de Cocultivo , Citocinas/farmacología , Humanos , Ratones , Estructura Molecular , Neuronas/citología , Neuronas/efectos de los fármacos , Osteoclastos/citología , Osteoclastos/efectos de los fármacos , Células PC12 , Feocromocitoma , Ratas , Proteínas Recombinantes/antagonistas & inhibidores , Células U937RESUMEN
Time-related changes in potential factors involved in hepatocarcinogenesis by DDT were investigated in a 4-week and a 2-year feeding studies of p,p'-DDT with F344 rats. In the 4-week study with males at doses of 50, 160, and 500 ppm, cell proliferation and gap junctional intercellular communication (GJIC) were examined after 1, 2, 3, 7, 14, and 28 days. Cell proliferation was enhanced within 3 days at any dose level, but returned to normal after 7 days, whereas GJIC was inhibited throughout the study. In the 2-year study with both sexes at doses of 5, 50, and 500 ppm, cell proliferation, GJIC, enzyme induction, and oxidative stress were investigated after 26, 52, 78, and 104 weeks. Males and females showed an inhibition of GJIC and increases in P450 isozymes (CYP2B1 and CYP3A2) in a dose-dependent manner at all time points, but no significant change in cell proliferation. Lipid peroxide for males at 50 and 500 ppm and 8-hydroxydeoxyguanosine for both sexes at 500 ppm were elevated throughout the study. Histologically, eosinophilic foci and hepatocellular adenomas increased in males at 50 ppm and both sexes at 500 ppm. Hepatocellular carcinomas also developed in males at 500 ppm. These results indicate that DDT may induce eosinophilic foci as a result of oxidative DNA damage and leads them to neoplasms in combination with its mitogenic activity and inhibitory effect on GJIC. Oxidative stress could be a key factor in hepatocarcinogenesis by DDT.