RESUMEN
BACKGROUND: With the recent development of endoscopic submucosal dissection (ESD), large oesophageal cancers can be removed with a single procedure, with few limits on the resectable range. However, after aggressive ESD, a major complication that arises is postoperative inflammation and stenosis that can considerably affect the patient's quality of life. AIMS: To examine a novel treatment combining ESD and the endoscopic transplantation of tissue-engineered cell sheets created using autologous oral mucosal epithelial cells, in a clinically relevant large animal model. METHODS: Oral mucosal epithelial cells, harvested from beagle dogs, were cultured under normal conditions at 37 degrees C, on temperature-responsive dishes. After ESD (5 cm in length, 180 degrees in range), cell sheets were harvested by a simple reduction in temperature to 20 degrees C, and transplanted by endoscopy. RESULTS: The transplanted cell sheets were able to adhere to and survive on the underlying muscle layers in the ulcer sites, providing an intact, stratified epithelium. Four weeks after surgery, complete wound healing, with no observable stenosis, was seen in the animals receiving autologous cell sheet transplantation. By contrast, noticeable fibrin mesh and host inflammation, consistent with the intermediate stages of wound healing, were observed in the control animals that received only ESD. CONCLUSIONS: These findings in a clinically relevant canine model show the effectiveness of a novel combined endoscopic approach for the potential treatment of oesophageal cancers that can effectively enhance wound healing and possibly prevent postoperative oesophageal stenosis.
Asunto(s)
Modelos Animales de Enfermedad , Células Epiteliales/trasplante , Enfermedades del Esófago/cirugía , Mucosa Bucal/citología , Ingeniería de Tejidos/métodos , Úlcera/cirugía , Animales , Perros , Enfermedades del Esófago/patología , Neoplasias Esofágicas/cirugía , Estenosis Esofágica/patología , Estenosis Esofágica/prevención & control , Esofagoscopía/métodos , Esófago/patología , Esófago/cirugía , Inmunohistoquímica/métodos , Masculino , Microscopía Electrónica de Rastreo/métodos , Complicaciones Posoperatorias/cirugía , Resultado del Tratamiento , Úlcera/patología , Cicatrización de Heridas/fisiologíaRESUMEN
Intermolecular interactions of human serum proteins with a hydrophilic nonmetalloporphyrin, 13,17-bis(1-carboxypropionyl)carbomoylethyl-8-ethenyl-2-hydroxy-3-hydroxyiminoethylidene-2,7,12,18-tetramethylporphyrin sodium salt (ATX-S10 (Na)), or a hydrophilic gallium-metalloporphyrin, diethylenetriamine pentaacetic acid ester of 2-[1-(2-hydroxy-ethoxy)ethyl]-4-vinyl-deuteroporphyrin (IX) Ga complex (ATN-2), were investigated using spectrophotometry. ATX-S10 (Na) caused a bathochromic shift with albumin, high-density lipoprotein and low-density lipoprotein, but little or no shift was observed with hemopexin, transferrin and immunoglobulin G. In contrast, ATN-2 displayed a bathochromic shift only with hemopexin. These results suggest that the association energy of ATX-S10 (Na) with albumin might be slightly greater than that with lipoproteins and that of ATN-2 with hemopexin might be greater than that with other serum proteins.
Asunto(s)
Proteínas Sanguíneas/química , Galio/química , Fármacos Fotosensibilizantes/química , Porfirinas/química , Humanos , Interacciones Hidrofóbicas e Hidrofílicas , Estructura Molecular , EspectrofotometríaRESUMEN
BACKGROUND: We compared the prognostic efficacy between the Japanese General Rules of Prostatic Cancer (JGRPC) and the Gleason grading system (GGS) by applying them to a single set of patients and assessing the survival outcome. METHODS: One hundred and seventy-six patients with previously untreated prostate cancer were studied. One experienced Japanese pathologist graded the slides with JGRPC. Another experienced American pathologist graded the same slides with the Gleason grading system. The JGRPC grades were correlated with the Gleason scores (GS) grouped into three (GS 2-4, 5-7 and 8-10) or four (GS 2-4, 5-6, 7 and 8-10) tiers. RESULTS: The highest cancer death rates were seen in the higher grade groups in both systems. Comparison of JGRPC grade and three-tiered grouping of the GS showed identical grades in 81 of 176 cases (46.0%). The overall kappa value of agreement was only 0.151. The 96 cases of JGRPC moderately differentiated carcinoma group contained two nearly equal-sized groups by the Gleason grading system, those with GS 5-7 (47cases) and GS 8-10 (49 cases). There was a significant difference in survival rate between the GS 5-7 and GS 8-10 groups. No significant differences were noted in the reverse analysis of survival by JGRPC groups within patients with the same GS three-tiered groups. Similar trends were seen when JGRPC was compared with the four-tiered grouping of the GS. CONCLUSION: Both JGRPC and the Gleason grading system are useful in estimating the prognosis of prostate cancer, but only a mild correlation was found between the two systems. The Gleason grading system may provide more prognostic information than JGRPC in the moderately differentiated group.
Asunto(s)
Adenocarcinoma/patología , Neoplasias de la Próstata/patología , Adenocarcinoma/clasificación , Adenocarcinoma/mortalidad , Anciano , Humanos , Masculino , Pronóstico , Neoplasias de la Próstata/clasificación , Neoplasias de la Próstata/mortalidad , Tasa de SupervivenciaRESUMEN
It was recently reported that intravenous administration of phorbol 12-myristate 13-acetate (PMA) showed a therapeutic effect in myelocytic leukemia patients. However, we previously observed that, in serum-free conditions, polymorphonuclear leucocytes (PMNs) were killed rapidly by exposure to PMA, suggesting the possibility of serious side effects. In this study, we found that PMA-induced necrosis of PMNs was prevented by serum, suggesting the existence of a "necrosis-suppressing factor". Next we tried to identify the serum factor. The hemopexins we purified were found to suppress necrosis of PMNs in a dose-dependent fashion. Hemopexins alone could not suppress necrosis, however, as it required the coexistence of another macromolecule such as albumin. Albumin promoted the suppressive activity of hemopexins in a dose-dependent fashion. These results strongly suggest that serum hemopexins may rescue mature PMNs from necrosis in the PMA-administered leukemia patient as previously reported, resulting in avoidance of serious side effects.
Asunto(s)
Antineoplásicos/antagonistas & inhibidores , Hemopexina/farmacología , Neutrófilos/efectos de los fármacos , Acetato de Tetradecanoilforbol/antagonistas & inhibidores , Animales , Bovinos , Supervivencia Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Hemopexina/aislamiento & purificación , Hemopexina/metabolismo , Humanos , Necrosis , Neutrófilos/citología , Albúmina Sérica/farmacología , Superóxidos/metabolismo , Porcinos , UltrafiltraciónRESUMEN
The purpose of this study was to determine the accuracy of Gleason scores in prostate needle biopsy diagnosis and to investigate factors affecting the accuracy of the tumor grade. A single pathologist reviewed 116 sets of prostate cancer biopsies and radical prostatectomy specimens. The following factors were examined to determine their effect on the accuracy of the biopsy Gleason scores: (i) relative tumor differentiation; (ii) pathological stage; (iii) amount of tissue in the biopsy specimen; (iv) amount of cancer tissue in the biopsy specimen; (v) tumor heterogeneity; (vi) clinical findings (prostate specific antigen value and digital rectal examination); and (vii) interobserver variability. In 53 cases the Gleason score of biopsy specimens was identical to the score of prostatectomy specimens (45.7%). Fifty-four cases (46.6%) of biopsy specimens were undergraded. The most common discrepancy was diagnosis of well-differentiated carcinoma in the biopsy but diagnosis of moderately differentiated tumor in the corresponding prostatectomy specimen. This discrepancy occurred when the amount of tumor in the biopsy was 3 mm or less. Biopsy and prostatectomy results showed less agreement when the original biopsy tumor grade rendered by nine different pathologists was used, suggesting that interobserver variability can adversely affect the accuracy of tumor grade. Clarifying the histologic criteria for distinguishing each grade, especially between Gleason grades 2 and 3, is important for accurate grading.
Asunto(s)
Adenocarcinoma/diagnóstico , Neoplasias de la Próstata/diagnóstico , Adenocarcinoma/sangre , Adenocarcinoma/cirugía , Biopsia con Aguja , Humanos , Masculino , Variaciones Dependientes del Observador , Examen Físico , Antígeno Prostático Específico/sangre , Neoplasias de la Próstata/sangre , Neoplasias de la Próstata/cirugía , Reproducibilidad de los ResultadosRESUMEN
Virus infection triggers innate responses to host cells including production of type I interferon (IFN). Since IFN production is also induced by treatment with poly(I:C), viral double-stranded (ds) RNA has been postulated to play a direct role in the process. In the present study, we investigated the effect of dsRNA binding proteins on virus-induced activation of the IFN-beta gene. We found that PACT, originally identified as protein activator for dsRNA-dependent protein kinase (PKR) and implicated in the regulation of translation, augmented IFN-beta gene activation induced by Newcastle disease virus. Concomitantly with the augmented activity of IFN-beta enhancer, increased activity of NF-kappaB and IRF-3 and IRF-7 was observed. For the observed effect, the dsRNA-binding activity of PACT was essential. We identified residues of PACT that interact with a presumptive target molecule to exert its function. Furthermore, PACT colocalized with viral replication complex in the infected cells. Thus the observed effect of PACT is novel and PACT is involved in the regulation of viral replication and results in a marked increase of cellular IFN-beta gene expression.
Asunto(s)
Proteínas Portadoras/metabolismo , Interferón beta/genética , Virus de la Enfermedad de Newcastle/patogenicidad , ARN Bicatenario/metabolismo , Proteínas de Unión al ARN , Ribonucleoproteínas/metabolismo , Secuencia de Aminoácidos , Animales , Sitios de Unión , Proteínas Portadoras/química , Proteínas Portadoras/genética , Línea Celular , Proteínas de Unión al ADN/metabolismo , Elementos de Facilitación Genéticos , Regulación de la Expresión Génica , Células HeLa , Humanos , Factor 3 Regulador del Interferón , Factor 7 Regulador del Interferón , Ratones , Datos de Secuencia Molecular , Mutación , FN-kappa B/metabolismo , Virus de la Enfermedad de Newcastle/inmunología , Virus de la Enfermedad de Newcastle/fisiología , Estructura Terciaria de Proteína , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Ribonucleoproteínas/química , Ribonucleoproteínas/genética , Homología de Secuencia de Aminoácido , Factores de Transcripción/metabolismo , Activación Transcripcional , Replicación ViralRESUMEN
BACKGROUND: Infection by virus or treatment with double-stranded RNA (dsRNA) results in the activation of transcription factors including IRF-3, IRF-7 and a pleiotropic regulator NF-kappaB by specific phosphorylation. These factors are important in triggering a cascade of antiviral responses. A protein kinase that is yet to be identified is responsible for the activation of these factors and plays a key role in the responses. RESULTS: The signal cascade was analysed using sensitive assays for the activation of IRF-3 and NF-kappaB, and various inhibitors. We found that the activation of IRF-3 and NF-kappaB by dsRNA or virus involves a process that is sensitive to Geldanamycin. Although the induction of NF-kappaB by dsRNA/virus and TNF-alpha involves common downstream pathways including IKK activation, the upstream, Geldanamycin-sensitive process was unique to the dsRNA/virus-induced signal. By an in vitro assay using cell extract, we found an inducible protein kinase activity with physiological specificity of IRF-3 phosphorylation. Furthermore, the same extract specifically phosphorylated IRF-7 in a similar manner. CONCLUSIONS: Double-stranded RNA or virus triggers a specific signal cascade that results in the activation of the IRF-3/-7 kinase we detected, which corresponds to the long-sought signalling machinery that is responsible for triggering the early phase of innate response. The signal branches to a common NF-kappaB activation cascade, thus resulting in the activation of a set of critical transcription factors for the response.
Asunto(s)
Proteínas de Unión al ADN/biosíntesis , FN-kappa B/biosíntesis , Virus de la Enfermedad de Newcastle/metabolismo , ARN Bicatenario/farmacología , Factores de Transcripción/biosíntesis , Benzoquinonas , Proteínas de Unión al ADN/antagonistas & inhibidores , Proteínas de Unión al ADN/genética , Electroforesis en Gel de Poliacrilamida , Activación Enzimática/efectos de los fármacos , Inducción Enzimática , Ensayo de Inmunoadsorción Enzimática , Regulación Enzimológica de la Expresión Génica , Vectores Genéticos , Células HeLa , Humanos , Immunoblotting , Factor 3 Regulador del Interferón , Factor 7 Regulador del Interferón , Lactamas Macrocíclicas , Fosforilación , Poli I-C/farmacología , Proteínas Serina-Treonina Quinasas/metabolismo , Quinonas/farmacología , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Inhibidores de Serina Proteinasa/farmacología , Transducción de Señal , Clorometilcetona de Tosilfenilalanila/farmacología , Factores de Transcripción/antagonistas & inhibidores , Factores de Transcripción/genética , Células Tumorales Cultivadas , Factor de Necrosis Tumoral alfa/metabolismoRESUMEN
[reaction: see text] Palladium-catalyzed intramolecular carbon-carbon bond formation of aryl halides and amide-enolates gave 4-arylisoquinoline derivatives in good yields, which were further converted into the isoquinoline alkaloids cherylline and latifine.
Asunto(s)
Alcaloides/síntesis química , Hidrocarburos Halogenados/química , Isoquinolinas/síntesis química , Lactamas/síntesis química , Alcaloides/química , Alcaloides/aislamiento & purificación , Alcaloides de Amaryllidaceae , Catálisis , Isoquinolinas/química , Lactamas/química , Lactamas/aislamiento & purificación , Estructura Molecular , Paladio/químicaRESUMEN
PERF 15 is a testicular germ cell specific fatty acid-binding protein (FABP) isolated from rat. Indirect immunofluorescent analysis of juvenile rat testis showed that there were some strongly PERF 15-positive spermatocytes. These cells showed unclear nuclear structure and were predicted to undergo apoptosis. Apoptosis in germ cells is an important regulatory event to limit the number of germ cells in the seminiferous epithelium, but the physiological significance and molecular mechanisms of this testicular germ cell apoptosis are poorly understood. To determine whether PERF 15 participates in germ cell apoptosis, juvenile rat testis was examined by immunohistochemical and terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) methods. Strongly PERF 15-positive cells and TUNEL-positive cells were co-localized in adjacent sections. Exposure to methoxyacetic acid (MAA), known to induce apoptosis in spermatocytes, increased the number of strongly PERF 15-positive cells in 25-day-old rats' testes. Therefore, it seems that PERF 15 is involved in both spermatogenesis and testicular germ cell apoptosis.
Asunto(s)
Apoptosis , Proteínas Portadoras/biosíntesis , Células Germinativas/metabolismo , Testículo/metabolismo , Acetatos/toxicidad , Animales , Anticuerpos Monoclonales , Apoptosis/efectos de los fármacos , Electroforesis en Gel de Poliacrilamida , Proteínas de Unión a Ácidos Grasos , Técnica del Anticuerpo Fluorescente Indirecta , Células Germinativas/patología , Inmunohistoquímica , Inmunosupresores/toxicidad , Etiquetado Corte-Fin in Situ , Inyecciones Intraperitoneales , Masculino , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Ratas , Ratas Wistar , Espermatogénesis , Testículo/citología , Testículo/efectos de los fármacos , Testículo/patologíaRESUMEN
Cellular genes including the type I interferon genes are activated in response to viral infection. We previously reported that IRF-3 (interferon regulatory factor 3) is specifically phosphorylated on serine residues and directly transmits a virus-induced signal from the cytoplasm to the nucleus, and then participates in the primary phase of gene induction. In this study, we analyzed the molecular mechanism of IRF-3 activation further. The formation of a stable homomeric complex of IRF-3 between the specifically phosphorylated IRF-3 molecules occurred. While virus-induced IRF-7 did not bind to p300, the phosphorylated IRF-3 complex formed a stable multimeric complex with p300 (active holocomplex). Competition using a synthetic phosphopeptide corresponding to the activated IRF-3 demonstrated that p300 directly recognizes the structure in the vicinity of the phosphorylated residues of IRF-3. These results indicated that the phosphorylation of serine residues at positions 385 and 386 is critical for the formation of the holocomplex, presumably through a conformational switch facilitating homodimer formation and the generation of the interaction interface with CBP/p300.
Asunto(s)
Proteínas de Unión al ADN/metabolismo , Virus de la Enfermedad de Newcastle/fisiología , Proteínas Nucleares/metabolismo , Transactivadores/metabolismo , Factores de Transcripción/metabolismo , Animales , Unión Competitiva , Línea Celular , Proteínas de Unión al ADN/genética , Proteína p300 Asociada a E1A , Factor 3 Regulador del Interferón , Factor 7 Regulador del Interferón , Ratones , Fosfopéptidos/metabolismo , Fosforilación , Mutación Puntual , Pruebas de Precipitina , Serina/genética , Factores de Transcripción/genéticaRESUMEN
Two different tendon-to-bone reattachment methods were compared to assess tensile strength and histologic repair. After sharp dissection, rabbit Achilles tendons were reattached to the calcaneus by one of two methods: to abraded cortical bone (group 1) or into a cancellous bone tunnel (group 2). After surgery, each rabbit had its long-leg hip spica-cast in plantar flexion for 3 weeks. The rabbits' tendon-bone junctions were harvested 1, 2, 4, 6, and 12 weeks after surgery. Three rabbits were used for each repair method at each point in time: 2 for strength testing and 1 for histologic analysis. After this preliminary study, tensile strength was tested with another 14 rabbits 2 weeks after surgery. At each advancing point in time, in both groups, increasing tendon-bone strength was found. Ultimate tensile strength was equivalent for test rabbits (both methods after 6 weeks) and control rabbits. There was no significant difference between methods at any point in time. Blinded pathologic evaluation reported similar healing with both methods over time. With both methods, healing occurred with Sharpey fibers attached to the superficial cortex, with tendon resorption occurring in the bone tunnel. The simple method of cortical reattachment was shown to be equal to the more complex bone-tunnel reattachment.
Asunto(s)
Tendón Calcáneo/cirugía , Calcáneo/cirugía , Traumatismos de los Tendones/cirugía , Tendón Calcáneo/patología , Animales , Calcáneo/patología , Conejos , Traumatismos de los Tendones/patología , Resistencia a la Tracción , Cicatrización de Heridas/fisiologíaRESUMEN
Normal mammalian vitreous humor maintains its avascularity after regression of hyaloid vessels. Neovascularization in adults is only detected under pathological conditions which suggests that antiangiogenic factors are present in the vitreous humor. To elucidate the mechanism of vitreal angiogenic inhibition, we investigated the effect of vitreous humor on cultured vascular endothelial cells. When bovine aortic endothelial cells were cultured in the presence of bovine vitreous humor in medium, a decrease in cell viability was observed within 24 h. Ascorbic acid from vitreous humor has been identified as a cell death inducing factor with high performance liquid chromatography (HPLC) and molecular mass analysis. Ascorbic acid reduced endothelial cell viability at concentrations normally present in vitreous humor. This effect was completely inhibited by antioxidants, N-acetylcysteine and catalase. Amongst the ascorbic acid derivatives tested, ascorbic acid 2-phosphate did not induce cell death, suggesting that the production of ascorbyl radical is required for induction of cell death. Furthermore, capillary formation in three-dimensional collagen gel cultures characteristic of vascular endothelial cells were disrupted in the presence of ascorbic acid. Since ascorbic acid is highly concentrated in ocular tissues, especially in vitreous humor, it may function as a neovascularization inhibitor.
Asunto(s)
Ácido Ascórbico/farmacología , Endotelio Vascular/efectos de los fármacos , Cuerpo Vítreo/química , Acetilcisteína/farmacología , Animales , Aorta , Ácido Ascórbico/análogos & derivados , Ácido Ascórbico/toxicidad , Catalasa/farmacología , Bovinos , Muerte Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Relación Dosis-Respuesta a Droga , Endotelio Vascular/citología , Cuerpo Vítreo/metabolismoRESUMEN
beta 1 Integrins are considered to be essential for the differentiation of bone-marrow B cells through an interaction with fibronectin-expressed bone-marrow stromal cells. The expression of very late antigens-4 (VLA-4) and -5 (VLA-5) by CD38bright bone-marrow cells in patients with multiple myeloma was measured by flow cytometry using specific monoclonal antibodies. The percentage of CD38bright bone-marrow cells appeared to correlated with that of bone-marrow plasma cells as judged by examination of bone-marrow smears (r = 0.911, P < 0.0001). Expression of VLA-4 and VLA-5 by CD38bright cells varied between patients, but the expression of VLA-4 was always equal to or greater than that of VLA-5. The ratio of VLA-4 to VLA-5 expression (VLA-4:VLA-5 ratio) was calculated and compared with the clinical features of the myeloma patients. A high VLA-4:VLA-5 ratio (> 2.0) was associated with the presence of plasmacytomas and urinary Bence-Jones protein was more common in this group. No other correlations between the clinical features of the disease and the expression of beta 1 integrins were found.
Asunto(s)
Antígenos CD , Células de la Médula Ósea/patología , Integrinas/biosíntesis , Mieloma Múltiple/fisiopatología , Receptores de Fibronectina/biosíntesis , Receptores Mensajeros de Linfocitos/biosíntesis , Receptores de Antígeno muy Tardío/biosíntesis , ADP-Ribosil Ciclasa , ADP-Ribosil Ciclasa 1 , Anciano , Antígenos de Diferenciación/análisis , Antígenos de Diferenciación/biosíntesis , Proteína de Bence Jones/orina , Células de la Médula Ósea/inmunología , Femenino , Humanos , Inmunoglobulina A/sangre , Inmunoglobulina G/sangre , Integrina alfa4beta1 , Integrinas/análisis , Masculino , Glicoproteínas de Membrana , Persona de Mediana Edad , Mieloma Múltiple/inmunología , Mieloma Múltiple/patología , NAD+ Nucleosidasa/análisis , NAD+ Nucleosidasa/biosíntesis , Estadificación de Neoplasias , Plasmacitoma/complicaciones , Receptores de Fibronectina/análisis , Receptores Mensajeros de Linfocitos/análisis , Receptores de Antígeno muy Tardío/análisisRESUMEN
Polymorphonuclear leucocytes (PMNs) circulating in mammalian peripheral blood are terminally differentiated cells, and once isolated in serum-free medium, they undergo apoptosis within 1 or 2 days. In this study, we studied the effects of phorbol myristate acetate (PMA) on the viability of porcine PMNs in vitro. PMA is known to suppress apoptosis in many cell types. PMA but not dioctanoyl glycerol (DOG) induced morphological degeneration and cell death within 3 to 5 hours as assessed by light microscopy observation and the MTT viability assay. This occurred despite the fact that DNA fragmentation associated with "spontaneous apoptosis" was not observed. Morphological degeneration and death were not due to the oxidative damage from superoxides or its metabolites produced by polymorphonuclear leucocytes, because PMA and DOG similarly stimulated superoxide production. Several other inactive phorbol derivatives tested did not cause cell death, suggesting that the toxicity of PMA did not result from non-specific effect of the reagent.
Asunto(s)
Apoptosis , Neutrófilos/efectos de los fármacos , Acetato de Tetradecanoilforbol/farmacología , Animales , Supervivencia Celular/efectos de los fármacos , Fragmentación del ADN/efectos de los fármacos , Diglicéridos/farmacología , Peróxido de Hidrógeno/metabolismo , NADPH Oxidasas/metabolismo , Neutrófilos/citología , Superóxidos/metabolismo , PorcinosRESUMEN
In this study, we report that phenylarsine oxide and ethanol, both of which suppress a number of polymorphonuclear leucocyte functions including superoxide production, prevented the phorbol myristate acetate-induced cell death in a dose-dependent manner. These reagents had an inhibitory effect even after polymorphonuclear leucocytes were stimulated to produce superoxide by treatment with phorbol myristate acetate. The results indicate that activation of protein kinase C and subsequent superoxide release do not directly cause phorbol myristate acetate-induced cell death. Phenylarsine oxide or ethanol prevents cell death by affecting pathways downstream from those involved in the superoxide production.
Asunto(s)
Arsenicales/metabolismo , Muerte Celular , Etanol/metabolismo , Neutrófilos/metabolismo , Acetato de Tetradecanoilforbol/metabolismo , Animales , Arsenicales/farmacología , Etanol/farmacología , Neutrófilos/citología , Neutrófilos/efectos de los fármacos , Proteína Quinasa C/metabolismo , Superóxidos/metabolismo , Porcinos , Acetato de Tetradecanoilforbol/farmacologíaRESUMEN
Treatment of U937 cells with dolichyl phosphate led to an increase in the activity of the ICE family protease CPP32, accompanied with cleavage of pre-CPP32 to generate p17. Peptide inhibitors YVAD-cmk and Z-Asp-CH2-DCB (specific to ICE) and DEVD-CHO (specific to CPP32) blocked the dolichyl phosphate-induced apoptosis. The dolichyl phosphate-induced increase of CPP32 activity was inhibited by adenylate cyclase inhibitors, SQ 22536 and 2',5'-dideoxyadenosine. Dolichyl phosphate caused a transient increase of intracellular cAMP concentration. The results suggest that modulation of cAMP synthesis due to the stimulation of adenylate cyclase by dolichyl phosphate plays a critical role in CPP32 activation and apoptosis.
Asunto(s)
Apoptosis , Caspasas , Cisteína Endopeptidasas/metabolismo , Fosfatos de Dolicol/farmacología , Leucemia Monocítica Aguda/enzimología , Adenina/análogos & derivados , Adenina/farmacología , Inhibidores de Adenilato Ciclasa , Adenilil Ciclasas/metabolismo , Caspasa 3 , AMP Cíclico/metabolismo , Fragmentación del ADN , Didesoxiadenosina/análogos & derivados , Didesoxiadenosina/farmacología , Activación Enzimática , Inhibidores Enzimáticos/farmacología , Precursores Enzimáticos/metabolismo , Humanos , Cinética , Células Tumorales CultivadasRESUMEN
To evaluate the role of various growth factors in naturally occurring cell death during development of the neural retina, we examined the effects of such factors on the nuclear morphology and the size of DNA in cultured chick embryonic neural retina cells. Basic fibroblast growth factor (bFGF) increased internucleosomal cleavage of DNA and nuclear fragmentation in a time- and dose-dependent manner. The effect was inhibited by anti-bFGF antibody, suramin, and cycloheximide. Epidermal growth factor, platelet-derived growth factor, nerve growth factor, tumor necrosis factor-alpha, and dexamethasone had no effect. These results provide evidence that bFGF may eventually act as a lethal factor inducing apoptotic cell death during the development of the neural retina in chick embryo.
Asunto(s)
Apoptosis/efectos de los fármacos , Factor 2 de Crecimiento de Fibroblastos/farmacología , Retina/citología , Retina/efectos de los fármacos , Animales , Núcleo Celular/ultraestructura , Embrión de Pollo , Cicloheximida/farmacología , ADN/efectos de los fármacos , ADN/genética , Fragmentación del ADN , Neuronas/efectos de los fármacos , Neuronas/fisiología , Concentración Osmolar , Inhibidores de la Síntesis de la Proteína/farmacologíaRESUMEN
3-Ketoglucose and similar ketosugars have been identified in microorganisms only and little is known about their functions. UDP-sugars are widely found as an intermediate in sugar metabolism in living organisms. Yet what role UDP-sugars play, or whether they play a direct role in metabolism, is still unknown. UDP-sugars were isolated and purified from bovine heart muscle, and a UDP-sugar fraction capable of NAD(P)H-dependent catalytic reduction of metmyoglobin was detected. Subsequent identification revealed that the active UDP-sugar was UDP-3- or UDP-4-ketoglucosamine. These compounds were purified from bovine cardiac muscle by ultrafiltration, anion-exchange column chromatography and reverse-phase chromatography. They were further characterized by determination of their chemical reducing activity, by comparison with synthetic UDP-3- or UDP-4-ketoglucosamine standards using high-performance liquid chromatography, by estimation of molecular mass using fast atom bombardment mass spectrometry, and by Fourier transform infrared microspectroscopy and electron probe microanalysis. The results suggest that UDP-3- or UDP-4-ketoglucosamine reduces metmyoglobin in bovine cardiac muscle. It is important that the reducing activity displayed by this ketosugar is not the effect of UDP-3- or UDP-4-ketoglucosamine alone but depends on NAD(P)H. In other words, this action of UDP-3- or UDP-4-ketoglucosamine is catalytic.