Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 18 de 18
Filtrar
Más filtros












Base de datos
Intervalo de año de publicación
1.
Int J Mol Sci ; 25(11)2024 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-38892314

RESUMEN

GV1001, an anticancer vaccine, exhibits other biological functions, including anti-inflammatory and antioxidant activity. It also suppresses the development of ligature-induced periodontitis in mice. Porphyromonas gingivalis (Pg), a major human oral bacterium implicated in the development of periodontitis, is associated with various systemic disorders, such as atherosclerosis and Alzheimer's disease (AD). This study aimed to explore the protective effects of GV1001 against Pg-induced periodontal disease, atherosclerosis, and AD-like conditions in Apolipoprotein (ApoE)-deficient mice. GV1001 effectively mitigated the development of Pg-induced periodontal disease, atherosclerosis, and AD-like conditions by counteracting Pg-induced local and systemic inflammation, partly by inhibiting the accumulation of Pg DNA aggregates, Pg lipopolysaccharides (LPS), and gingipains in the gingival tissue, arterial wall, and brain. GV1001 attenuated the development of atherosclerosis by inhibiting vascular inflammation, lipid deposition in the arterial wall, endothelial to mesenchymal cell transition (EndMT), the expression of Cluster of Differentiation 47 (CD47) from arterial smooth muscle cells, and the formation of foam cells in mice with Pg-induced periodontal disease. GV1001 also suppressed the accumulation of AD biomarkers in the brains of mice with periodontal disease. Overall, these findings suggest that GV1001 holds promise as a preventive agent in the development of atherosclerosis and AD-like conditions associated with periodontal disease.


Asunto(s)
Apolipoproteínas E , Aterosclerosis , Enfermedades Periodontales , Porphyromonas gingivalis , Animales , Ratones , Apolipoproteínas E/deficiencia , Enfermedades Periodontales/microbiología , Enfermedades Periodontales/prevención & control , Aterosclerosis/metabolismo , Aterosclerosis/prevención & control , Aterosclerosis/microbiología , Telomerasa/metabolismo , Fragmentos de Péptidos/farmacología , Enfermedad de Alzheimer/metabolismo , Enfermedad de Alzheimer/prevención & control , Enfermedad de Alzheimer/microbiología , Periodontitis/microbiología , Periodontitis/prevención & control , Infecciones por Bacteroidaceae/microbiología , Infecciones por Bacteroidaceae/complicaciones , Infecciones por Bacteroidaceae/prevención & control , Modelos Animales de Enfermedad , Ratones Endogámicos C57BL , Masculino , Humanos
2.
Food Chem (Oxf) ; 8: 100203, 2024 Jul 30.
Artículo en Inglés | MEDLINE | ID: mdl-38633725

RESUMEN

Fruit and vegetable wastes are linked to the depletion of natural resources and can pose serious health and environmental risks (e.g. eutrophication, water and soil pollution, and GHG emissions) if improperly managed. Current waste management practices often fail to recover high-value compounds from fruit wastes. Among emerging valorization methods, the utilization of fruit wastes as a feedstock for microalgal biorefineries is a promising approach for achieving net zero waste and sustainable development goals. This is due to the ability of microalgae to efficiently sequester carbon dioxide through photosynthesis, utilize nutrients in wastewater, grow in facilities located on non-arable land, and produce several commercially valuable compounds with applications in food, biofuels, bioplastics, cosmetics, nutraceuticals, pharmaceutics, and various other industries. However, the application of microalgal biotechnology towards upcycling fruit wastes has yet to be implemented on the industrial scale due to several economic, technical, operational, and regulatory challenges. Here, we identify sources of fruit waste along the food supply chain, evaluate current and emerging fruit waste management practices, describe value-added compounds in fruit wastes, and review current methods of microalgal cultivation using fruit wastes as a fermentation medium. We also propose some novel strategies for the practical implementation of industrial microalgal biorefineries for upcycling fruit waste in the future.

3.
Int J Mol Sci ; 24(16)2023 Aug 08.
Artículo en Inglés | MEDLINE | ID: mdl-37628753

RESUMEN

GV1001, a 16 amino acid peptide derived from the catalytic segment of human telomerase reverse transcriptase, was developed as an anti-cancer vaccine. Subsequently, it was found to exhibit anti-inflammatory and anti-Alzheimer's disease properties. Periodontitis is a risk factor for a variety of systemic diseases, including atherosclerosis, a process in which chronic systemic and vascular inflammation results in the formation of plaques containing lipids, macrophages, foam cells, and tissue debris on the vascular intima. Thus, we investigated the effect of GV1001 on the severity of ligature-induced periodontitis, vascular inflammation, and arterial lipid deposition in mice. GV1001 notably reduced the severity of ligature-induced periodontitis by inhibiting gingival and systemic inflammation, alveolar bone loss, and vascular inflammation in wild-type mice. It also significantly lowered the amount of lipid deposition in the arterial wall in ApoE-deficient mice receiving ligature placement without changing the serum lipid profile. In vitro, we found that GV1001 inhibited the Receptor Activator of NF-κB ligand (RANKL)-induced osteoclast formation and tumor necrosis factor-α (TNF-α)-induced phenotypic changes in endothelial cells. In conclusion, our study suggests that GV1001 prevents the exacerbation of periodontitis and atherosclerosis associated with periodontitis partly by inhibiting local, systemic, and vascular inflammation and phenotypic changes of vascular endothelial cells.


Asunto(s)
Aterosclerosis , Vacunas contra el Cáncer , Periodontitis , Humanos , Animales , Ratones , Células Endoteliales , Arterias , Inflamación , Vacunas de Subunidad
4.
J Can Dent Assoc ; 87: l7, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-34343070

RESUMEN

The field of artificial intelligence (AI) has experienced spectacular development and growth over the past two decades. With recent progress in digitized data acquisition, machine learning and computing infrastructure, AI applications are expanding into areas that were previously thought to be reserved for human experts. When applied to medicine and dentistry, AI has tremendous potential to improve patient care and revolutionize the health care field. In dentistry, AI is being investigated for a variety of purposes, specifically identification of normal and abnormal structures, diagnosis of diseases and prediction of treatment outcomes. This review describes some current and future applications of AI in dentistry.


Asunto(s)
Inteligencia Artificial , Aprendizaje Automático , Odontología , Predicción , Humanos
5.
Cell ; 173(3): 792-803.e19, 2018 04 19.
Artículo en Inglés | MEDLINE | ID: mdl-29656897

RESUMEN

Microscopy is a central method in life sciences. Many popular methods, such as antibody labeling, are used to add physical fluorescent labels to specific cellular constituents. However, these approaches have significant drawbacks, including inconsistency; limitations in the number of simultaneous labels because of spectral overlap; and necessary perturbations of the experiment, such as fixing the cells, to generate the measurement. Here, we show that a computational machine-learning approach, which we call "in silico labeling" (ISL), reliably predicts some fluorescent labels from transmitted-light images of unlabeled fixed or live biological samples. ISL predicts a range of labels, such as those for nuclei, cell type (e.g., neural), and cell state (e.g., cell death). Because prediction happens in silico, the method is consistent, is not limited by spectral overlap, and does not disturb the experiment. ISL generates biological measurements that would otherwise be problematic or impossible to acquire.


Asunto(s)
Colorantes Fluorescentes/química , Procesamiento de Imagen Asistido por Computador/métodos , Microscopía Fluorescente/métodos , Neuronas Motoras/citología , Algoritmos , Animales , Línea Celular Tumoral , Supervivencia Celular , Corteza Cerebral/citología , Humanos , Células Madre Pluripotentes Inducidas/citología , Aprendizaje Automático , Redes Neurales de la Computación , Neurociencias , Ratas , Programas Informáticos , Células Madre/citología
6.
Hum Mol Genet ; 26(19): 3699-3712, 2017 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-28934389

RESUMEN

Deletion of the 16p11.2 CNV affects 25 core genes and is associated with multiple symptoms affecting brain and body, including seizures, hyperactivity, macrocephaly, and obesity. Available data suggest that most symptoms are controlled by haploinsufficiency of two or more 16p11.2 genes. To identify interacting 16p11.2 genes, we used a pairwise partial loss of function antisense screen for embryonic brain morphology, using the accessible zebrafish model. fam57ba, encoding a ceramide synthase, was identified as interacting with the doc2a gene, encoding a calcium-sensitive exocytosis regulator, a genetic interaction not previously described. Using genetic mutants, we demonstrated that doc2a+/- fam57ba+/- double heterozygotes show hyperactivity and increased seizure susceptibility relative to wild-type or single doc2a-/- or fam57ba-/- mutants. Additionally, doc2a+/- fam57ba+/- double heterozygotes demonstrate the increased body length and head size. Single doc2a+/- and fam57ba+/- heterozygotes do not show a body size increase; however, fam57ba-/- homozygous mutants show a strongly increased head size and body length, suggesting a greater contribution from fam57ba to the haploinsufficient interaction between doc2a and fam57ba. The doc2a+/- fam57ba+/- interaction has not been reported before, nor has any 16p11.2 gene previously been linked to increased body size. These findings demonstrate that one pair of 16p11.2 homologs can regulate both brain and body phenotypes that are reflective of those in people with 16p11.2 deletion. Together, these findings suggest that dysregulation of ceramide pathways and calcium sensitive exocytosis underlies seizures and large body size associated with 16p11.2 homologs in zebrafish. The data inform consideration of mechanisms underlying human 16p11.2 deletion symptoms.


Asunto(s)
Trastorno Autístico/genética , Trastorno Autístico/metabolismo , Proteínas de Unión al Calcio/genética , Trastornos de los Cromosomas/genética , Trastornos de los Cromosomas/metabolismo , Discapacidad Intelectual/genética , Discapacidad Intelectual/metabolismo , Proteínas del Tejido Nervioso/genética , Oxidorreductasas/genética , Animales , Animales Modificados Genéticamente , Tamaño Corporal/genética , Encéfalo/metabolismo , Proteínas de Unión al Calcio/metabolismo , Deleción Cromosómica , Cromosomas Humanos Par 16/genética , Cromosomas Humanos Par 16/metabolismo , Variaciones en el Número de Copia de ADN , Modelos Animales de Enfermedad , Exocitosis/genética , Humanos , Proteínas del Tejido Nervioso/metabolismo , Oxidorreductasas/metabolismo , Fenotipo , Convulsiones/genética , Pez Cebra , Proteínas de Pez Cebra/genética , Proteínas de Pez Cebra/metabolismo
7.
Proc Natl Acad Sci U S A ; 114(5): 1165-1170, 2017 01 31.
Artículo en Inglés | MEDLINE | ID: mdl-28028237

RESUMEN

Mutations in leucine-rich repeat kinase 2 (LRRK2) and α-synuclein lead to Parkinson's disease (PD). Disruption of protein homeostasis is an emerging theme in PD pathogenesis, making mechanisms to reduce the accumulation of misfolded proteins an attractive therapeutic strategy. We determined if activating nuclear factor erythroid 2-related factor (Nrf2), a potential therapeutic target for neurodegeneration, could reduce PD-associated neuron toxicity by modulating the protein homeostasis network. Using a longitudinal imaging platform, we visualized the metabolism and location of mutant LRRK2 and α-synuclein in living neurons at the single-cell level. Nrf2 reduced PD-associated protein toxicity by a cell-autonomous mechanism that was time-dependent. Furthermore, Nrf2 activated distinct mechanisms to handle different misfolded proteins. Nrf2 decreased steady-state levels of α-synuclein in part by increasing α-synuclein degradation. In contrast, Nrf2 sequestered misfolded diffuse LRRK2 into more insoluble and homogeneous inclusion bodies. By identifying the stress response strategies activated by Nrf2, we also highlight endogenous coping responses that might be therapeutically bolstered to treat PD.


Asunto(s)
Proteína 2 Quinasa Serina-Treonina Rica en Repeticiones de Leucina/antagonistas & inhibidores , Factor 2 Relacionado con NF-E2/fisiología , Proteínas del Tejido Nervioso/metabolismo , Neuronas/efectos de los fármacos , Enfermedad de Parkinson/metabolismo , alfa-Sinucleína/antagonistas & inhibidores , Animales , Corteza Cerebral/citología , Genes Reporteros , Células HEK293 , Humanos , Hidroquinonas/farmacología , Cuerpos de Inclusión , Células Madre Pluripotentes Inducidas/citología , Proteína 2 Quinasa Serina-Treonina Rica en Repeticiones de Leucina/metabolismo , Proteína 2 Quinasa Serina-Treonina Rica en Repeticiones de Leucina/toxicidad , Factor 2 Relacionado con NF-E2/biosíntesis , Factor 2 Relacionado con NF-E2/genética , Neuronas/metabolismo , Cultivo Primario de Células , Agregación Patológica de Proteínas , Proteostasis , Ratas , Proteínas Recombinantes de Fusión/metabolismo , Análisis de la Célula Individual , Factores de Tiempo , alfa-Sinucleína/metabolismo , alfa-Sinucleína/toxicidad
8.
Arterioscler Thromb Vasc Biol ; 34(7): 1437-45, 2014 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-24855060

RESUMEN

OBJECTIVE: The site-specificity of endothelial phenotype is attributable to the local hemodynamic forces. The flow regulation of microRNAs in endothelial cells (ECs) plays a significant role in vascular homeostasis and diseases. The objective of this study was to elucidate the molecular mechanism by which the pulsatile shear flow-induced microRNA-23b (miR-23b) exerts antiproliferative effects on ECs. APPROACH AND RESULTS: We used a combination of a cell perfusion system and experimental animals to examine the flow regulation of miR-23b in modulating EC proliferation. Our results demonstrated that pulsatile shear flow induces the transcription factor Krüppel-like factor 2 to promote miR-23b biosynthesis; the increase in miR-23b then represses cyclin H to impair the activity and integrity of cyclin-dependent kinase-activating kinase (CAK) complex. The inhibitory effect of miR-23b on CAK exerts dual actions to suppress cell cycle progression, and reduce basal transcription by deactivating RNA polymerase II. Whereas pulsatile shear flow regulates the miR-23b/CAK pathway to exert antiproliferative effects on ECs, oscillatory shear flow has little effect on the miR-23b/CAK pathway and hence does not cause EC growth arrest. Such flow pattern-dependent phenomena are validated with an in vivo model on rat carotid artery: the flow disturbance induced by partial carotid ligation led to a lower expression of miR-23b and a higher EC proliferation in comparison with the pulsatile flow regions of the unligated vessels. Local delivery of miR-23b mitigated the proliferative EC phenotype in partially ligated vessels. CONCLUSIONS: Our findings unveil a novel mechanism by which hemodynamic forces modulate EC proliferative phenotype through the miR-23b/CAK pathway.


Asunto(s)
Enfermedades de las Arterias Carótidas/enzimología , Proliferación Celular , Ciclina H/metabolismo , Quinasas Ciclina-Dependientes/metabolismo , Células Endoteliales/enzimología , Células Endoteliales de la Vena Umbilical Humana/enzimología , MicroARNs/metabolismo , Transcripción Genética , Animales , Enfermedades de las Arterias Carótidas/genética , Enfermedades de las Arterias Carótidas/fisiopatología , Puntos de Control del Ciclo Celular , Células Cultivadas , Ciclina H/genética , Quinasas Ciclina-Dependientes/genética , Modelos Animales de Enfermedad , Humanos , Factores de Transcripción de Tipo Kruppel/metabolismo , Masculino , Mecanotransducción Celular , MicroARNs/genética , Perfusión , Fenotipo , Flujo Pulsátil , Interferencia de ARN , ARN Polimerasa II/metabolismo , Ratas , Ratas Sprague-Dawley , Flujo Sanguíneo Regional , Estrés Mecánico , Factores de Tiempo , Transfección , Quinasa Activadora de Quinasas Ciclina-Dependientes
9.
Dis Model Mech ; 5(6): 834-51, 2012 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-22566537

RESUMEN

Deletion or duplication of one copy of the human 16p11.2 interval is tightly associated with impaired brain function, including autism spectrum disorders (ASDs), intellectual disability disorder (IDD) and other phenotypes, indicating the importance of gene dosage in this copy number variant region (CNV). The core of this CNV includes 25 genes; however, the number of genes that contribute to these phenotypes is not known. Furthermore, genes whose functional levels change with deletion or duplication (termed 'dosage sensors'), which can associate the CNV with pathologies, have not been identified in this region. Using the zebrafish as a tool, a set of 16p11.2 homologs was identified, primarily on chromosomes 3 and 12. Use of 11 phenotypic assays, spanning the first 5 days of development, demonstrated that this set of genes is highly active, such that 21 out of the 22 homologs tested showed loss-of-function phenotypes. Most genes in this region were required for nervous system development - impacting brain morphology, eye development, axonal density or organization, and motor response. In general, human genes were able to substitute for the fish homolog, demonstrating orthology and suggesting conserved molecular pathways. In a screen for 16p11.2 genes whose function is sensitive to hemizygosity, the aldolase a (aldoaa) and kinesin family member 22 (kif22) genes were identified as giving clear phenotypes when RNA levels were reduced by ∼50%, suggesting that these genes are deletion dosage sensors. This study leads to two major findings. The first is that the 16p11.2 region comprises a highly active set of genes, which could present a large genetic target and might explain why multiple brain function, and other, phenotypes are associated with this interval. The second major finding is that there are (at least) two genes with deletion dosage sensor properties among the 16p11.2 set, and these could link this CNV to brain disorders such as ASD and IDD.


Asunto(s)
Encefalopatías/genética , Encéfalo/embriología , Cromosomas Humanos Par 16/genética , Eliminación de Gen , Dosificación de Gen/genética , Genoma Humano/genética , Pez Cebra/genética , Animales , Axones/efectos de los fármacos , Encéfalo/efectos de los fármacos , Encéfalo/patología , Encefalopatías/embriología , Encefalopatías/patología , Secuencia Conservada/genética , Embrión no Mamífero/anomalías , Embrión no Mamífero/efectos de los fármacos , Embrión no Mamífero/patología , Regulación del Desarrollo de la Expresión Génica/efectos de los fármacos , Humanos , Morfolinos/farmacología , Movimiento/efectos de los fármacos , Especificidad de Órganos/efectos de los fármacos , Especificidad de Órganos/genética , Fenotipo , ARN Interferente Pequeño/metabolismo , Homología de Secuencia de Ácido Nucleico , Pez Cebra/embriología , Proteínas de Pez Cebra/genética , Proteínas de Pez Cebra/metabolismo
10.
PLoS One ; 6(5): e20588, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-21637783

RESUMEN

High grade gliomas (HGG) are one of the leading causes of cancer-related deaths in children, and there is increasing evidence that pediatric HGG may harbor distinct molecular characteristics compared to adult tumors. We have sought to clarify the role of microsatellite instability (MSI) in pediatric versus adult HGG. MSI status was determined in 144 patients (71 pediatric and 73 adults) using a well established panel of five quasimonomorphic mononucleotide repeat markers. Expression of MLH1, MSH2, MSH6 and PMS2 was determined by immunohistochemistry, MLH1 was assessed for mutations by direct sequencing and promoter methylation using MS-PCR. DNA copy number profiles were derived using array CGH, and mutations in eighteen MSI target genes studied by multiplex PCR and genotyping. MSI was found in 14/71 (19.7%) pediatric cases, significantly more than observed in adults (5/73, 6.8%; p = 0.02, Chi-square test). MLH1 expression was downregulated in 10/13 cases, however no mutations or promoter methylation were found. MSH6 was absent in one pediatric MSI-High tumor, consistent with an inherited mismatch repair deficiency associated with germline MSH6 mutation. MSI was classed as Type A, and associated with a remarkably stable genomic profile. Of the eighteen classic MSI target genes, we identified mutations only in MSH6 and DNAPKcs and described a polymorphism in MRE11 without apparent functional consequences in DNA double strand break detection and repair. This study thus provides evidence for a potential novel molecular pathway in a proportion of gliomas associated with the presence of MSI.


Asunto(s)
Silenciador del Gen , Genes Relacionados con las Neoplasias/genética , Genoma Humano/genética , Glioma/genética , Inestabilidad de Microsatélites , Adolescente , Adulto , Anciano , Secuencia de Bases , Niño , Roturas del ADN de Doble Cadena , Reparación de la Incompatibilidad de ADN/genética , Proteínas de Unión al ADN/genética , Femenino , Mutación del Sistema de Lectura/genética , Humanos , Lactante , Proteína Homóloga de MRE11 , Masculino , Persona de Mediana Edad , Datos de Secuencia Molecular , Polimorfismo Genético , Adulto Joven
11.
J Hosp Med ; 5(9): 514-20, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-21162153

RESUMEN

BACKGROUND: Patient satisfaction is typically measured by quantitative surveys using predetermined domains. However, dissatisfaction may be an entity distinct from satisfaction, may have different determinants, and may better reflect problems in healthcare delivery. OBJECTIVE: The aim of this study was to describe domains of dissatisfaction experienced by patients during hospitalization. SETTING: The setting was a U.S. urban academic medical center. PATIENTS: The patients were adults discharged between July 1, 2007 and June 30, 2008 INTERVENTION: The intervention was a postdischarge telephone interview: "If there was one thing we could have done to improve your experience in the hospital, what would it have been?" MEASUREMENTS: The measurements were standard qualitative analysis of suggestions for improvement. RESULTS: We randomly selected 976 of 9,764 interviews. A total of 439/976 (45.0%) included at least one suggestion for improvement. We identified six major domains of dissatisfaction: ineptitude (7.7%), disrespect (6.1%), waits (15.8%), ineffective communication (7.4%), lack of environmental control (15.6%), and substandard amenities (6.9%). These domains corresponded to six implicit expectations for quality hospital care: safety, treatment with respect and dignity, minimized wait times, effective communication, control over physical surroundings, and high-quality amenities. Some of these expectations, such as for safe care, effective communication between providers, and lack of disrespect, may not be adequately captured in existing patient satisfaction assessments. CONCLUSIONS: The results represent patient-generated priorities for quality improvement in healthcare. These priorities are not all consistently represented in standard patient satisfaction surveys and quality improvement initiatives. Patient input is critical to assessing the quality of hospital care and to identifying areas for improvement.


Asunto(s)
Centros Médicos Académicos/normas , Satisfacción del Paciente , Adolescente , Femenino , Hospitalización , Humanos , Entrevistas como Asunto , Masculino , Garantía de la Calidad de Atención de Salud , Estados Unidos , Adulto Joven
12.
Mol Cell Biol ; 26(4): 1195-208, 2006 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-16449635

RESUMEN

DEXD/H box putative RNA helicases are required for pre-rRNA processing in Saccharomyces cerevisiae, although their exact roles and substrates are unknown. To characterize the significance of the conserved motifs for helicase function, a series of five mutations were created in each of the eight essential RNA helicases (Has1, Dbp6, Dbp10, Mak5, Mtr4, Drs1, Spb4, and Dbp9) involved in 60S ribosomal subunit biogenesis. Each mutant helicase was screened for the ability to confer dominant negative growth defects and for functional complementation. Different mutations showed different degrees of growth inhibition among the helicases, suggesting that the conserved regions do not function identically in vivo. Mutations in motif I and motif II (the DEXD/H box) often conferred dominant negative growth defects, indicating that these mutations do not interfere with substrate binding. In addition, mutations in the putative unwinding domains (motif III) demonstrated that conserved amino acids are often not essential for function. Northern analysis of steady-state RNA from strains expressing mutant helicases showed that the dominant negative mutations also altered pre-rRNA processing. Coimmunoprecipitation experiments indicated that some RNA helicases associated with each other. In addition, we found that yeasts disrupted in expression of the two nonessential RNA helicases, Dbp3 and Dbp7, grew worse than when either one alone was disrupted.


Asunto(s)
ARN Helicasas/genética , ARN Helicasas/metabolismo , Ribosomas/metabolismo , Saccharomyces cerevisiae/enzimología , Saccharomyces cerevisiae/genética , Alelos , Secuencia Conservada , Genes Fúngicos , Complejos Multiproteicos , Mutación , ARN Helicasas/química , Precursores del ARN/metabolismo , Procesamiento Postranscripcional del ARN , ARN de Hongos/metabolismo , Saccharomyces cerevisiae/metabolismo
13.
J Pharmacol Exp Ther ; 313(2): 840-7, 2005 May.
Artículo en Inglés | MEDLINE | ID: mdl-15701710

RESUMEN

We evaluated the effects of 4-(5-chloro-2-hydroxyphenyl)-3-(2-hydroxyethyl)-6-(trifluoromethyl)-quinolin-2(1H)-one (BMS-223131), an opener of large conductance Ca(2+)-activated potassium (maxi-K) channels, on normal and stress-exacerbated colonic motility and visceral nociception in the rat. Fecal output was employed as an index of motility. Visceral nociception, in response to intracolonic balloon distension (10-90 mm Hg; 30 s duration), was evaluated using one of three indices: change in blood pressure, abdominal withdrawal, or myoelectrical activity. BMS-223131 (2, 6, or 20 mg/kg i.p.) produced a small but dose-dependent and significant reduction in cumulative 24-h fecal output. Fecal output in response to stress (1-h restraint plus bursts of air to the face) was markedly inhibited by BMS-223131, and moisture content was significantly reduced. With regard to visceral pain, the transient and distention-dependent reduction in arterial pressure in anesthetized animals was inhibited by BMS-223131 in a dose-dependent manner. Distension-induced abdominal withdrawal in conscious rats was also dose-dependently attenuated by BMS-223131. BMS-223131 at a dose of 20 mg/kg markedly attenuated the increase in myoelectrical activity evoked by balloon distention in conscious animals. BMS-223131 was also evaluated in viscerally hypersensitive rats (sensitized as neonates by intracolonic mustard oil) where it produced a robust dose-dependent attenuation of the abdominal withdrawal response. Compared with naive animals, BMS-223131 was more potent in the sensitized animals. Thus, BMS-223131 effectively reduced stress-induced colonic motility and visceral nociception supporting the potential utility of maxi-K channel openers for the treatment of bowel disorders involving dysfunctional motility and visceral sensitivity.


Asunto(s)
Colon/efectos de los fármacos , Motilidad Gastrointestinal/efectos de los fármacos , Dimensión del Dolor/efectos de los fármacos , Canales de Potasio Calcio-Activados/agonistas , Canales de Potasio Calcio-Activados/fisiología , Quinolonas/administración & dosificación , Estrés Fisiológico/tratamiento farmacológico , Animales , Presión Sanguínea/efectos de los fármacos , Presión Sanguínea/fisiología , Colon/fisiología , Relación Dosis-Respuesta a Droga , Femenino , Motilidad Gastrointestinal/fisiología , Activación del Canal Iónico/efectos de los fármacos , Activación del Canal Iónico/fisiología , Canales de Potasio de Gran Conductancia Activados por el Calcio , Dimensión del Dolor/métodos , Quinolinas/administración & dosificación , Quinolinas/química , Quinolonas/química , Ratas , Ratas Wistar , Estrés Fisiológico/fisiopatología , Vísceras/efectos de los fármacos , Vísceras/fisiología
14.
Cell Cycle ; 4(1): 177-82, 2005 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-15611643

RESUMEN

Human MDC1/NFBD1 has been found to interact with key players of the DNA-damage response machinery. Here, we identify and describe a functional homologue of MDC1/ NFBD1 in Mus musculus. The mouse homologue, mMDC1, retains the key motifs identified in the human protein and in response to ionizing radiation forms foci that co-localize with the MRE11-RAD50-NBS1 (MRN) complex and factors such as gammaH2AX and 53BP1. In addition, mMDC1 is associated with DNA damage sites generated during meiotic recombination as well as the X and Y chromosomes during the late stages of meiotic prophase I. Finally, whereas MDC1 shows strong colocalization with the MRN complex in response to DNA damage it does not co-localize with the MRN complex on replicating chromatin. These data suggest that mMDC1 is a marker for both exogenously and endogenously generated DNA double-stranded breaks and that its interaction with the MRN complex is initiated exclusively by DNA damage.


Asunto(s)
Proteínas de Ciclo Celular/metabolismo , Daño del ADN , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Proteínas Nucleares/metabolismo , Proteínas Adaptadoras Transductoras de Señales , Secuencias de Aminoácidos , Secuencia de Aminoácidos , Animales , Proteínas de Ciclo Celular/genética , Línea Celular , Rotura Cromosómica , Enzimas Reparadoras del ADN , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/fisiología , Genes cdc/fisiología , Histonas/genética , Histonas/fisiología , Humanos , Péptidos y Proteínas de Señalización Intracelular/química , Péptidos y Proteínas de Señalización Intracelular/genética , Proteína Homóloga de MRE11 , Meiosis/genética , Meiosis/fisiología , Ratones , Datos de Secuencia Molecular , Proteínas Nucleares/genética , Radiación Ionizante , Recombinación Genética , Sus scrofa
15.
DNA Repair (Amst) ; 3(8-9): 959-67, 2004.
Artículo en Inglés | MEDLINE | ID: mdl-15279782

RESUMEN

At close hand to one's genomic material are the histones that make up the nucleosome. Standing guard, one variant stays hidden doubling as one of the core histones. But, thanks to its prime positioning, a variation in the tail of H2AX enables rapid modification of the histone code in response to DNA damage. A role for H2AX phosphorylation has been demonstrated in DNA repair, cell cycle checkpoints, regulated gene recombination events, and tumor suppression. In this review, we summarize what we have learned about this marker of DNA breaks, and highlight some of the questions that remain to be elucidated about the physiological role of H2AX. We also suggest a model in which chromatin restructuring mediated by H2AX phosphorylation serves to concentrate DNA repair/signaling factors and/or tether DNA ends together, which could explain the pleotropic phenotypes observed in its absence.


Asunto(s)
Daño del ADN , Reparación del ADN , Histonas/fisiología , Recombinación Genética , Animales , Ciclo Celular , Genoma , Histonas/genética , Humanos , Meiosis , Modelos Biológicos , Modelos Genéticos , Fenotipo , Fosforilación , Serina/química , Transducción de Señal
16.
Nat Cell Biol ; 5(7): 675-9, 2003 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-12792649

RESUMEN

Histone H2AX is rapidly phosphorylated in the chromatin micro-environment surrounding a DNA double-strand break (DSB). Although H2AX deficiency is not detrimental to life, H2AX is required for the accumulation of numerous essential proteins into irradiation induced foci (IRIF). However, the relationship between IRIF formation, H2AX phosphorylation (gamma-H2AX) and the detection of DNA damage is unclear. Here, we show that the migration of repair and signalling proteins to DSBs is not abrogated in H2AX(-/-) cells, or in H2AX-deficient cells that have been reconstituted with H2AX mutants that eliminate phosphorylation. Despite their initial recruitment to DSBs, numerous factors, including Nbs1, 53BP1 and Brca1, subsequently fail to form IRIF. We propose that gamma-H2AX does not constitute the primary signal required for the redistribution of repair complexes to damaged chromatin, but may function to concentrate proteins in the vicinity of DNA lesions. The differential requirements for factor recruitment to DSBs and sequestration into IRIF may explain why essential regulatory pathways controlling the ability of cells to respond to DNA damage are not abolished in the absence of H2AX.


Asunto(s)
Núcleo Celular/genética , Cromatina/genética , Daño del ADN/genética , Células Eucariotas/metabolismo , Histonas/deficiencia , Animales , Línea Celular , Daño del ADN/efectos de la radiación , Reparación del ADN/genética , Proteínas de Unión al ADN/genética , Histonas/genética , Humanos , Ratones , Proteínas Nucleares/genética , Fosforilación , Transducción de Señal/genética
17.
Transgenic Res ; 12(2): 171-8, 2003 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-12739885

RESUMEN

When knockout mice are used to test the efficacy of recombinant human proteins, the animals often develop antibodies to the enzyme, precluding long-term pre-clinical studies. This has been a problem with a number of models, for example, the evaluation of gene or enzyme replacement therapies in a knockout model of glycogen storage disease type II (GSDII; Pompe syndrome). In this disease, the lack of acid alpha-glucosidase (GAA) results in lysosomal accumulation of glycogen, particularly in skeletal and cardiac muscle. Here, we report that in a GAA-deficient mouse model of GSDII, low levels of transgene-encoded human GAA expressed in skeletal muscle or liver dramatically blunt or abolish the immune response to human recombinant protein. Of two low expression transgenic lines, only the liver-expressing line exhibited a profound GAA deficiency in skeletal muscle and heart indistinguishable from that in the original knockouts. The study suggests that the induction of tolerance in animal models of protein deficiencies could be achieved by restricting the expression of a gene of interest to a particular, carefully chosen tissue.


Asunto(s)
alfa-Glucosidasas/inmunología , Animales , Autoanticuerpos/biosíntesis , Células CHO , Cricetinae , Modelos Animales de Enfermedad , Enfermedad del Almacenamiento de Glucógeno Tipo II/terapia , Humanos , Hígado/enzimología , Ratones , Ratones Noqueados , Ratones Transgénicos , Fenotipo , Proteínas Recombinantes/inmunología , alfa-Glucosidasas/genética
18.
Mol Ther ; 6(5): 601-8, 2002 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-12409258

RESUMEN

Although many lysosomal disorders are corrected by a small amount of the missing enzyme, it has been generally accepted that 20-30% of normal acid alpha-glucosidase (GAA) activity, provided by gene or enzyme replacement therapy, would be required to reverse the myopathy and cardiomyopathy in Pompe disease. We have addressed the issue of reversibility of the disease in the Gaa(-/-) mouse model. We have made transgenic lines expressing human GAA in skeletal and cardiac muscle of Gaa(-/-) mice, and we turned the transgene on at different stages of disease progression by using a tetracycline-controllable system. We have demonstrated that levels of 20-30% of normal activity are indeed sufficient to clear glycogen in the heart of young Gaa(-/-) mice, but not in older mice with a considerably higher glycogen load. However, in skeletal muscle-a major organ affected in infantile and in milder, late-onset variants in humans-induction of GAA expression in young Gaa(-/-) mice to levels greatly exceeding wildtype values did not result in full phenotypic correction, and some muscle fibers showed little or no glycogen clearance. The results demonstrate that complete reversal of pathology in skeletal muscle or long-affected heart muscle will require much more enzyme than previously expected or a different approach.


Asunto(s)
Técnicas de Transferencia de Gen , Glucógeno/metabolismo , Músculo Esquelético/metabolismo , alfa-Glucosidasas/genética , Animales , Western Blotting , Cardiomiopatías , Femenino , Enfermedad del Almacenamiento de Glucógeno Tipo II/genética , Humanos , Ratones , Ratones Noqueados , Ratones Transgénicos , Mutación , Miocardio/citología , Fenotipo , Transgenes
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...