RESUMEN
Cancer cells exhibit dramatic alterations of chromatin organization at cis-regulatory elements, but the molecular basis, extent, and impact of these alterations are still being unraveled. Here, we identify extensive genome-wide modification of sites bearing the active histone mark H3K4me2 in primary human colorectal cancers, as compared with corresponding benign precursor adenomas. Modification of certain colorectal cancer sites highlighted the activity of the transcription factor CNOT3, which is known to control self-renewal of embryonic stem cells (ESC). In primary colorectal cancer cells, we observed a scattered pattern of CNOT3 expression, as might be expected for a tumor-initiating cell marker. Colorectal cancer cells exhibited nuclear and cytoplasmic expression of CNOT3, suggesting possible roles in both transcription and mRNA stability. We found that CNOT3 was bound primarily to genes whose expression was affected by CNOT3 loss, and also at sites modulated in certain types of colorectal cancers. These target genes were implicated in ESC and cancer self-renewal and fell into two distinct groups: those dependent on CNOT3 and MYC for optimal transcription and those repressed by CNOT3 binding and promoter hypermethylation. Silencing CNOT3 in colorectal cancer cells resulted in replication arrest. In clinical specimens, early-stage tumors that included >5% CNOT3+ cells exhibited a correlation to worse clinical outcomes compared with tumors with little to no CNOT3 expression. Together, our findings implicate CNOT3 in the coordination of colonic epithelial cell self-renewal, suggesting this factor as a new biomarker for molecular and prognostic classification of early-stage colorectal cancer. Cancer Res; 77(3); 766-79. ©2016 AACR.
Asunto(s)
Neoplasias Colorrectales/patología , Regulación Neoplásica de la Expresión Génica/fisiología , Células Madre Neoplásicas/patología , Factores de Transcripción/metabolismo , Animales , Biomarcadores de Tumor/análisis , Inmunoprecipitación de Cromatina , Neoplasias Colorrectales/metabolismo , Neoplasias Colorrectales/mortalidad , Células Madre Embrionarias/metabolismo , Células Madre Embrionarias/patología , Perfilación de la Expresión Génica , Xenoinjertos , Humanos , Inmunohistoquímica , Estimación de Kaplan-Meier , Ratones , Ratones Endogámicos NOD , Células Madre Neoplásicas/metabolismo , Análisis de Secuencia por Matrices de Oligonucleótidos , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Análisis de Matrices Tisulares , TranscriptomaRESUMEN
Recent studies have suggested that two polymorphisms of the beta(2)-adrenergic receptor (beta(2)AR) gene at codons 16 (arginine to glycine) and 27 (glutamine to glutamate) affect an individual's airway responsiveness, or response to acute or chronic beta(2)-agonist therapy but are not risk factors for asthma. We hypothesize that there is an interaction effect on asthma between the beta(2)AR gene polymorphisms and cigarette smoking. A case-control study was conducted in 128 asthma cases and 136 control individuals identified from 10,014 studied subjects in rural Anqing, China. Allele-specific polymerase chain reaction (PCR) was used to genotype beta(2)AR gene polymorphisms. Multiple logistic regression was used to adjust for potential confounding factors. We found a marginally significant interaction between cigarette smoking and beta(2)AR-16 genotype after adjusting for important confounding factors (p = 0.06). Specifically, we found that compared with never-smoking Gly-16 homozygotes, those ever-smokers who are Arg-16 homozygotes had a significantly increased risk of asthma (odds ratio [OR] = 7.81; 95% confidence interval [CI]: 2.07 to 29.5). This association showed a clear dose-response relationship with the number of cigarettes smoked. However, there was no significant association of asthma with polymorphisms of the beta(2)AR at position 27 (OR = 1.38; 95% CI: 0.69 to 2.73). Our study suggests a gene-environment interaction between the Arg-16 genotype and ever cigarette smoking with respect to the susceptibility of an individual to asthma.
Asunto(s)
Asma/etiología , Predisposición Genética a la Enfermedad/genética , Polimorfismo Genético/genética , Receptores Adrenérgicos beta 2/genética , Fumar/efectos adversos , Adulto , Asma/diagnóstico , Asma/epidemiología , Estudios de Casos y Controles , China/epidemiología , Factores de Confusión Epidemiológicos , Femenino , Volumen Espiratorio Forzado , Genotipo , Homocigoto , Humanos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Reacción en Cadena de la Polimerasa , Prevalencia , Factores de Riesgo , Distribución por Sexo , Encuestas y CuestionariosRESUMEN
BACKGROUND: Regular use of inhaled beta-adrenergic agonists may have adverse effects in some asthma patients. Polymorphisms of the beta(2)-adrenergic receptor (beta(2)-AR) can affect its regulation; however, results of smaller studies of the effects of such polymorphisms on response to beta-agonist therapy have been inconsistent. METHODS: We examined the possible effects of polymorphisms at codons 16 (beta(2)-AR-16) and 27 (beta(2)-AR-27) on response to albuterol by genotyping 190 asthmatics who had participated in a trial of regular versus as-needed albuterol use. RESULTS: During the 16-week treatment period, patients homozygous for arginine (Arg/Arg) at beta(2)-AR-16 who used albuterol regularly had a small decline in morning peak expiratory flow (AM PEF). This effect was magnified during a 4-week run-out period, when all patients returned to as-needed albuterol only. By the end of the study, Arg/Arg subjects who had used albuterol regularly had an AM PEF 30.5 +/- 12.1 liters/min lower (p = 0.012) than Arg/Arg patients who had used albuterol as needed only. Subjects homozygous for glycine at beta(2)-AR-16 showed no such decline. Evening PEF also declined in the Arg/Arg regular but not in as-need albuterol users. No significant differences between regular and as-needed treatment were associated with polymorphisms at beta(2)-AR-27. CONCLUSIONS: Polymorphisms of the beta(2)-AR may influence airway responses to regular inhaled beta-agonist treatment.
Asunto(s)
Agonistas Adrenérgicos beta/uso terapéutico , Albuterol/uso terapéutico , Asma/tratamiento farmacológico , Asma/genética , Polimorfismo Genético , Receptores Adrenérgicos beta 2/genética , Adolescente , Adulto , Niño , Estudios de Cohortes , Femenino , Genotipo , Humanos , Masculino , Ápice del Flujo Espiratorio/efectos de los fármacos , Factores de TiempoRESUMEN
An increased concentration of nitric oxide (NO) in exhaled air (FENO) is now recognized as a critical component of the asthmatic phenotype. When we identified patients with asthma on the basis of a standard case definition alone, we found that they were remarkably heterogeneous with respect to their FENO. However, when we included genotype at a prominent asthma candidate gene (i.e., NOS1) in the case definition, and determined the number of AAT repeats in intron 20, we identified a remarkably homogeneous cohort of patients with respect to FENO. Both mean FENO (p = 0.00008) and variability around the mean (p = 0.000002) were significantly lower in asthmatic individuals with a high number (> or = 12) of AAT repeats at this locus than in those with fewer repeats. These data provide a biologically tenable link between genotype at a candidate gene in a region of linkage, NOS1, and an important component of the asthmatic phenotype, FENO. We show that addition of NOS1 genotype to the case definition of asthma allows the identification of a uniform cohort of patients, with respect to FENO, that would have been indistinguishable by other physiologic criteria. Our isolation of this homogeneous cohort of patients ties together the well-established associations among asthma, increased concentrations of NO in the exhaled air of asthmatic individuals, and variations of trinucleotide repeat sequences as identified in several neurologic conditions.
Asunto(s)
Asma/fisiopatología , Proteínas del Tejido Nervioso/genética , Óxido Nítrico Sintasa/genética , Óxido Nítrico/fisiología , Adulto , Asma/genética , Secuencia de Bases , Estudios de Cohortes , ADN/genética , Femenino , Frecuencia de los Genes/genética , Genotipo , Humanos , Masculino , Persona de Mediana Edad , Datos de Secuencia Molecular , Óxido Nítrico Sintasa de Tipo I , Fenotipo , Estadísticas no ParamétricasRESUMEN
We examined the influence of two common polymorphic forms of the beta(2)-adrenergic receptor (beta(2)AR): the Gly16 and Glu27 alleles, on acute and long-term beta(2)AR desensitization in human airway smooth muscle (HASM) cells. In cells from 15 individuals, considered without respect to genotype, pretreatment with Isoproterenol (ISO) at 10(-7) M for 1 h or 24 h caused approximately 25% and 64% decreases in the ability of subsequent ISO (10(-6) M) stimulation to reduce HASM cell stiffness as measured by magnetic twisting cytometry. Similar results were obtained with ISO-induced cyclic adenosine monophosphate (cAMP) as the outcome indicator. Data were then stratified post hoc by genotype. Cells containing at least one Glu27 allele (equivalent to presence of the Gly16Glu27 haplotype) showed significantly greater acute desensitization than did cells with no Glu27 allele, whether ISO-induced cell stiffness (34% versus 19%, p < 0.03) or cAMP formation (58% versus 11%, p < 0.02) was measured. Likewise, cells with any Glu27 allele showed greater long-term desensitization of cell stiffness and cAMP formation responses than did cells without the Glu27 allele. The distribution of genotypes limited direct conclusions about the influence of the Gly16 allele. However, presence of the Gly16Gln27 haplotype was associated with less acute and long-term desensitization of ISO-induced cAMP formation than was seen in cells without the Gly16Gln27 haplotype (14% versus 47%, p < 0.09 for short-term desensitization; 32% versus 84%, p < 0.01 for long-term desensitization), suggesting that the influence of Glu27 is not through its association with Gly16. The Glu27 allele was in strong linkage disequilibrium with the Arg19 allele, a polymorphic form of the beta(2)AR upstream peptide of the 5'-leader cistron of the beta(2)AR, and this polymorphism in the beta(2)AR 5'-flanking region may explain the effects of the Glu27 allele. Cells with any Arg19 allele showed significantly greater acute and long-term desensitization of ISO-induced cAMP formation than did cells without the Arg19 allele (54% versus 2%, p < 0.01 for short-term desensitization; 73% versus 35%, p < 0.05 for long-term desensitization). Similar results were obtained for ISO-induced changes in cell stiffness. Thus, the presence of the Glu27 allele is associated with increased acute and long-term desensitization in HASM.
Asunto(s)
Músculo Liso/fisiología , Polimorfismo Genético/genética , Receptores Adrenérgicos beta 2/genética , Agonistas Adrenérgicos beta/farmacología , Alelos , Análisis de Varianza , Secuencia de Bases , Bucladesina/farmacología , Células Cultivadas , Relación Dosis-Respuesta a Droga , Genotipo , Humanos , Indometacina/farmacología , Isoproterenol/farmacología , Datos de Secuencia Molecular , Músculo Liso/citología , Músculo Liso/efectos de los fármacos , Polimorfismo Genético/efectos de los fármacos , Polimorfismo Genético/fisiología , Receptores Adrenérgicos beta 2/efectos de los fármacos , Receptores Adrenérgicos beta 2/fisiología , Factores de Tiempo , Tráquea/citologíaRESUMEN
BACKGROUND: Polymorphisms of the beta(2) adrenoceptor influence receptor function in vitro and asthma phenotypes in vivo. However, their importance in determining responses to inhaled beta agonist treatment has not been clearly defined. METHODS: In a retrospective analysis of previously published data we have examined relationships between polymorphisms at codons 16 and 27 of the beta(2) adrenoceptor and clinical outcomes in a randomised, placebo controlled, crossover trial of regularly scheduled salbutamol and salmeterol in 115 patients with mild to moderate asthma. Genotyping was obtained for positions 16 and 27 in 108 and 107 patients, respectively. For position 16, 17 patients (16%) were homozygous Arg-Arg, 40 (37%) were heterozygous Arg-Gly, and 51 (47%) were homozygous Gly-Gly. RESULTS: Within the homozygous Arg-16 group major exacerbations were more frequent during salbutamol treatment than with placebo (1.91 (95% CI 1.07 to 3.12) per year versus 0.81 (95% CI 0.28 to 1.66) per year; p = 0.005). No significant treatment related differences occurred for heterozygous Arg-Gly patients (salbutamol 0.11 (95% CI 0.01 to 0.40), placebo 0.54 (95% CI 0.26 to 1.00) exacerbations per year) or homozygous Gly-16 patients (salbutamol 0.38 (95% CI 0.17 to 0.73), placebo 0.30 (95% CI 0.12 to 0.61) exacerbations per year). No adverse changes occurred for any position 16 subgroup with salmeterol. There was no significant relationship between position 27 genotypes and treatment related outcomes. CONCLUSION: Homozygous Arg-16 patients are susceptible to clinically important increases in asthma exacerbations during chronic dosing with the short acting beta(2) agonist salbutamol.
Asunto(s)
Agonistas Adrenérgicos beta/uso terapéutico , Albuterol/análogos & derivados , Albuterol/uso terapéutico , Asma/tratamiento farmacológico , Asma/genética , Polimorfismo Genético , Receptores Adrenérgicos beta 2/genética , Adolescente , Adulto , Estudios Cruzados , Método Doble Ciego , Femenino , Genotipo , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Xinafoato de Salmeterol , Resultado del TratamientoRESUMEN
Inhaled beta-adrenergic agonists are the most commonly used medications for the treatment of asthma although there is evidence that regular use may produce adverse effects in some patients. Polymorphisms of the beta(2)-adrenergic receptor (beta(2)-AR) can affect regulation of the receptor. Smaller studies examining the effects of such polymorphisms on the response to beta-agonist therapy have produced inconsistent results. We examined whether polymorphisms at codon 16 (beta(2)-AR-16) and codon 27 (beta(2)-AR-27) of the beta(2)-AR might affect the response to regular versus as-needed use of albuterol by genotyping the 190 asthmatics who had participated in a trial examining the effects of regular versus as needed albuterol use. During the 16-wk treatment period there was a small decline in morning peak expiratory flow in patients homozygous for arginine at B(2)-AR-16 (Arg/Arg) who used albuterol regularly. This effect was magnified during a 4-wk run out period, during which all patients returned to using as-needed albuterol, so that by the end of the study Arg Arg patients who had regularly used albuterol had a morning peak expiratory flow 30. 5 +/- 12.1 L/min lower (p = 0.012) than Arg/Arg patients who had used albuterol on an as needed basis. There was no decline in peak flow with regular use of albuterol in patients who were homozygous for glycine at beta(2)-AR-16. Evening peak expiratory flow also declined in the Arg/Arg patients who used albuterol regularly but not in those who used albuterol on an as-needed basis. No significant differences in outcomes between regular and as-needed treatment were associated with polymorphisms at position 27 of the beta(2)-AR. No other differences in asthma outcomes that we investigated occurred in relation to these beta(2)-AR polymorphisms. Polymorphisms of the beta(2)-AR may influence airway responses to regular inhaled beta-agonist treatment.
Asunto(s)
Albuterol/uso terapéutico , Asma/tratamiento farmacológico , Asma/genética , Broncodilatadores/uso terapéutico , Polimorfismo Genético/efectos de los fármacos , Receptores Adrenérgicos beta 2/genética , Adolescente , Niño , Método Doble Ciego , Femenino , Genotipo , Humanos , MasculinoRESUMEN
Recent family-based studies have revealed evidence for linkage of chromosomal region 12q to both asthma and high total serum immunoglobulin E (IgE) levels. Among the candidate genes in this region for asthma is neuronal nitric oxide synthase (NOS1). We sought a genetic association between a polymorphism in the NOS1 gene and the diagnosis of asthma, using a case-control design. Frequencies for allele 17 and 18 of a CA repeat in exon 29 of the NOS1 gene were significantly different between 490 asthmatic and 350 control subjects. Allele 17 was more common in the asthmatics (0.83 vs 0.76, or 1.49 [95% CI 1.17-1.90], P = 0.013) while allele 18 was less common in the asthmatics (0.06 vs 0.12, or 0.49 [95% CI 0.34-0. 69], P = 0.0004). To confirm these results we genotyped an additional 1131 control subjects and found the frequencies of alleles 17 and 18 to be virtually identical to those ascertained in our original control subjects. Total serum IgE was not associated with any allele of the polymorphism. These findings provide support, from case-control association analysis, for NOS1 as a candidate gene for asthma.
Asunto(s)
Asma/enzimología , Asma/genética , Óxido Nítrico Sintasa/genética , Polimorfismo Genético/genética , Adulto , Anciano , Anciano de 80 o más Años , Alelos , Asma/inmunología , Estudios de Casos y Controles , Repeticiones de Dinucleótido/genética , Exones/genética , Frecuencia de los Genes/genética , Genotipo , Humanos , Inmunoglobulina E/sangre , Modelos Logísticos , Masculino , Persona de Mediana Edad , Modelos Genéticos , Óxido Nítrico Sintasa de Tipo I , Oportunidad Relativa , Estados Unidos , Población Blanca/genéticaRESUMEN
Quantitative trait locus (QTL) mapping was used to identify chromosomal regions contributing to airway hyperresponsiveness in mice. Airway responsiveness to methacholine was measured in A/J and C3H/HeJ parental strains as well as in progeny derived from crosses between these strains. QTL mapping of backcross [(A/J x C3H/HeJ) x C3H/HeJ] progeny (n = 137-227 informative mice for markers tested) revealed two significant linkages to loci on chromosomes 6 and 7. The QTL on chromosome 6 confirms the previous report by others of a linkage in this region in the same genetic backgrounds; the second QTL, on chromosome 7, represents a novel locus. In addition, we obtained suggestive evidence for linkage (logarithm of odds ratio = 1.7) on chromosome 17, which lies in the same region previously identified in a cross between A/J and C57BL/6J mice. Airway responsiveness in a cross between A/J and C3H/HeJ mice is under the control of at least two major genetic loci, with evidence for a third locus that has been previously implicated in an A/J and C57BL/6J cross; this indicates that multiple genetic factors control the expression of this phenotype.
Asunto(s)
Asma/genética , Hiperreactividad Bronquial/genética , Mapeo Cromosómico , Animales , Hiperreactividad Bronquial/inducido químicamente , Pruebas de Provocación Bronquial , Broncoconstrictores , Cromosomas , Ligamiento Genético , Genotipo , Masculino , Cloruro de Metacolina , Ratones , Ratones Endogámicos A , Ratones Endogámicos C3H , Carácter Cuantitativo HeredableRESUMEN
Suppressor of cytokine signaling (SOCS) proteins are involved in the negative regulation of cytokine-induced STAT (signal transducers and activators of transcription) factor signaling. We cloned genomic regions of SOCS1 and SOCS2 genes and mapped these genes to chromosome 16p12-p13.1 and chromosome 12q21.3-q23 regions, respectively, by cytogenetic and radiation hybrid mapping. In addition, we mapped SOCS2 by yeast artificial chromosome (YAC) pool screening to YAC contig WC 12.5 on chromosome 12 with an unambiguous hit to CHLC.ATA19H12 and WI-5940, which is 461.5 cR from the top of the map.
Asunto(s)
Proteínas Portadoras/genética , Cromosomas Humanos Par 12 , Cromosomas Humanos Par 16 , Proteínas de Unión al ADN , Péptidos y Proteínas de Señalización Intracelular , Proteínas/genética , Proteínas Represoras , Transactivadores , Mapeo Cromosómico , Cromosomas Artificiales de Levadura , Clonación Molecular , Citocinas/metabolismo , Humanos , Células Híbridas , Hibridación Fluorescente in Situ , Transducción de Señal , Proteína 1 Supresora de la Señalización de Citocinas , Proteínas Supresoras de la Señalización de CitocinasRESUMEN
Clinically similar asthma patients may develop airway obstruction by different mechanisms. Asthma treatments that specifically interfere with the 5-lipoxygenase (ALOX5) pathway provide a method to identify those patients in whom the products of the ALOX5 pathway (that is, the leukotrienes) contribute to the expression of the asthma phenotype. Failure of an asthma patient to respond to treatment with ALOX5-pathway modifiers indicates that leukotrienes are not critical to the expression of the asthmatic phenotype in that patient. We previously defined a family of DNA sequence variants in the core promoter of the gene ALOX5 (on chromosome 10q11.2) associated with diminished promoter-reporter activity in tissue culture. Because expression of ALOX5 is in part transcriptionally regulated, we reasoned that patients with these sequence variants may have diminished gene transcription, and therefore decreased ALOX5 product production and a diminished clinical response to treatment with a drug targeting this pathway. Such an effect indicates an interaction between gene promoter sequence variants and drug-treatment responses, that is, a pharmacogenetic effect of a promoter sequence on treatment responses.
Asunto(s)
Antiasmáticos/uso terapéutico , Araquidonato 5-Lipooxigenasa/genética , Asma/tratamiento farmacológico , Asma/genética , Hidroxiurea/análogos & derivados , Regiones Promotoras Genéticas , Alelos , Asma/enzimología , Frecuencia de los Genes , Variación Genética , Humanos , Hidroxiurea/uso terapéutico , Inhibidores de la Lipooxigenasa/uso terapéutico , Fenotipo , Resultado del TratamientoRESUMEN
Asthma is a chronic disease characterized by increased airway responsiveness and airway inflammation. The functional role of nitric oxide (NO) and the various nitric oxide synthase (NOS) isoforms in human asthma is controversial. To investigate the role of NO in an established model of allergic asthma, mice with targeted deletions of the three known isoforms of NOS (NOS1, 2, and 3) were studied. Although the inducible (NOS2) isoform was significantly upregulated in the lungs of ovalbumin (OVA)-sensitized and -challenged (OVA/OVA) wild-type (WT) mice and was undetectable in similarly treated NOS2-deficient mice, airway responsiveness was not significantly different between these groups. OVA/OVA endothelial (NOS3)-deficient mice were significantly more responsive to methacholine challenge compared with similarly treated NOS1 and NOS1&3-deficient mice. Airway responsiveness in OVA/OVA neuronal (NOS1)-deficient and neuronal/endothelial (NOS1&3) double-deficient mice was significantly less than that observed in similarly treated NOS2 and WT groups. These findings demonstrate an important function for the nNOS isoform in controlling the inducibility of airway hyperresponsiveness in this model of allergic asthma.
Asunto(s)
Asma/inmunología , Óxido Nítrico Sintasa/deficiencia , Neumonía/inmunología , Animales , Asma/enzimología , Asma/etiología , Líquido del Lavado Bronquioalveolar/citología , Calcio/metabolismo , Modelos Animales de Enfermedad , Marcación de Gen/métodos , Histocitoquímica , Humanos , Isoenzimas/deficiencia , Pulmón/enzimología , Cloruro de Metacolina , Ratones , Ratones Noqueados , Ovalbúmina , PletismografíaRESUMEN
Arachidonate 5-lipoxygenase-activating protein (ALOX5AP) is an arachidonic acid binding protein that has been shown to be critical in the biosynthesis of leukotrienes. We mapped the ALOX5AP gene to the chromosome 13q12 region by cytogenetic mapping, yeast artificial chromosome (YAC) pool screening, and radiation hybrid mapping. It was mapped to YAC contig WC13.2 by YAC pool screening with an unambiguous hit to WI-4874, which is at 78 cR on the radiation hybrid map, 3.36 cR, by radiation hybrid mapping, from WI-4874.
Asunto(s)
Proteínas Portadoras/genética , Cromosomas Humanos Par 13/genética , Proteínas de la Membrana/genética , Proteínas Activadoras de la 5-Lipooxigenasa , Humanos , Hibridación in Situ , Leucotrienos/genética , Mapeo Físico de Cromosoma/métodosRESUMEN
We examined the role of the interleukin-8 (IL-8) receptor in a murine model of allergen-induced pulmonary inflammation using mice with a targeted deletion of the murine IL-8 receptor homologue (IL-8r-/-). Wild-type (Wt) and IL-8r-/- mice were systemically immunized to ovalbumin (OVA) and were exposed with either single or multiple challenge of aerosolized phosphate-buffered saline (OVA/PBS) or OVA (OVA/OVA). Analysis of cells recovered from bronchoalveolar lavage (BAL) revealed a diminished recruitment of neutrophils to the airway lumen after single challenge in IL-8r-/- mice compared with Wt mice, whereas multiply challenged IL-8r-/- mice had increased B cells and fewer neutrophils compared with Wt mice. Both Wt and IL-8r-/- OVA/OVA mice recruited similar numbers of eosinophils to the BAL fluid and exhibited comparable degrees of pulmonary inflammation histologically. Both total and OVA-specific IgE levels were greater in multiply challenged IL-8r-/- OVA/OVA mice than in Wt mice. Both the IL-8r-/- OVA/OVA and OVA/PBS mice were significantly less responsive to methacholine than their respective Wt groups, but both Wt and IL-8r mice showed similar degrees of enhancement after multiple allergen challenge. The data demonstrate that the IL-8r modulates IgE production, airway responsiveness, and the composition of the cells (B cells and neutrophils) recruited to the airway lumen in response to antigen.
Asunto(s)
Alérgenos/inmunología , Antígenos CD/inmunología , Linfocitos B/inmunología , Inmunoglobulina E/biosíntesis , Pulmón/inmunología , Ovalbúmina/inmunología , Receptores de Interleucina/inmunología , Animales , Antígenos CD/genética , Linfocitos B/citología , Recuento de Células Sanguíneas , Lavado Broncoalveolar , Broncoconstrictores/farmacología , Citometría de Flujo , Pulmón/patología , Linfocitos/citología , Masculino , Cloruro de Metacolina/farmacología , Ratones , Ratones Endogámicos BALB C , Ratones Noqueados , Proteínas/metabolismo , Receptores de Interleucina/genética , Receptores de Interleucina-8ARESUMEN
Asthma is a common, but heterogeneous disease, characterized by reversible airway obstruction, bronchial hyperresponsiveness (BHR); and is commonly associated with atopy. The messenger molecule nitric oxide (NO), that is formed by neuronal NO synthase (NOS1), is known to have a key role in bronchomotor control in animals. In humans the gene for NOS1 is located on chromosome 12q24, in a region that had been shown in family studies to be linked to the diagnosis of asthma. We identified variants of the NOS1 gene, and assessed whether there was a genetic association between these variants of NOS1 and the diagnosis asthma. A total of 410 Caucasian asthma patients and 228 Caucasian controls were screened for three bi-allelic polymorphisms in the NOS1 gene that had been detected by single-stranded conformational polymorphism (SSCP) analysis and confirmed by sequencing. Allele frequencies of a polymorphism in exon 29 of the NOS1 gene were significantly different between asthmatics and controls (P<0.05). These findings suggest that variants of the NOS1 gene may be one source of genetic risk for asthma.
Asunto(s)
Asma/genética , Óxido Nítrico Sintasa/genética , Exones , Humanos , Mutación , Óxido Nítrico Sintasa de Tipo I , Polimorfismo Conformacional Retorcido-SimpleRESUMEN
Thiamine-responsive megaloblastic anemia, also known as "TRMA" or "Rogers syndrome," is an early-onset autosomal recessive disorder defined by the occurrence of megaloblastic anemia, diabetes mellitus, and sensorineural deafness, responding in varying degrees to thiamine treatment. On the basis of a linkage analysis of affected families of Alaskan and of Italian origin, we found, using homozygosity mapping, that the TRMA-syndrome gene maps to a region on chromosome 1q23.2-23.3 (maximum LOD score of 3.7 for D1S1679). By use of additional consanguineous kindreds of Israeli-Arab origin, the putative disease-gene interval also has been confirmed and narrowed, suggesting genetic homogeneity. Linkage analysis generated the highest combined LOD-score value, 8.1 at a recombination fraction of 0, with marker D1S2799. Haplotype analysis and recombination events narrowed the TRMA locus to a 16-cM region between markers D1S194 and D1S2786. Several heterozygote parents had diabetes mellitus, deafness, or megaloblastic anemia, which raised the possibility that mutations at this locus predispose carriers in general to these manifestations. Characterization of the metabolic defect of TRMA may shed light on the role of thiamine deficiency in such common diseases.
Asunto(s)
Anemia Megaloblástica/genética , Cromosomas Humanos Par 1/genética , Diabetes Mellitus Tipo 1/genética , Genes Recesivos , Pérdida Auditiva Sensorineural/genética , Tiamina/uso terapéutico , Alaska , Anemia Megaloblástica/tratamiento farmacológico , Anemia Megaloblástica/etnología , Árabes , Mapeo Cromosómico , Consanguinidad , Diabetes Mellitus Tipo 1/etnología , Femenino , Haplotipos/genética , Pérdida Auditiva Sensorineural/etnología , Homocigoto , Humanos , Israel/etnología , Italia/etnología , Escala de Lod , Masculino , Repeticiones de Microsatélite , Linaje , Federación de Rusia/etnología , SíndromeRESUMEN
The association of subclasses of Alu repetitive elements with various classes of trinucleotide and tetranucleotide microsatellites was characterized as a first step toward advancing our understanding of the evolution of microsatellite repeats. In addition, information regarding the association of specific classes of microsatellites with families of Alu elements was used to facilitate the development of genetic markers. Sequences containing Alu repeats were eliminated because unique primers could not be designed. Various classes of microsatellites are associated with different classes of Alu repeats. Very abundant and poly(A)-rich microsatellite classes (ATA, AATA) are frequently associated with an evolutionarily older subclass of Alu repeats, AluSx, whereas most of GATA and CA microsatellites are associated with a recent Alu subfamily, AluY. Our observations support all three possible mechanisms for the association of Alu repeats to microsatellites. Primers designed using a set of sequences from a particular microsatellite class showed higher homology with more sequences of that class than probes designed for other classes. We developed an efficient method of prescreening GGAA and ATA microsatellite clones for Alu repeats with probes designed in this study. We also showed that Alu probes labeled in a single reaction (multiplex labeling) could be used efficiently for prescreening of GGAA clones. Sequencing of these prescreened GGAA microsatellites revealed only 5% Alu repeats. Prescreening with primers designed for ATA microsatellite class resulted in the reduction of the loss of markers from approximately 50% to 10%. The new Alu probes that were designed have also proved to be useful in Alu-Alu fingerprinting.
Asunto(s)
Mapeo Cromosómico , Genoma Humano , Repeticiones de Microsatélite/genética , Secuencias Repetitivas de Ácidos Nucleicos , Animales , Cromosomas Artificiales de Levadura , Humanos , RatonesRESUMEN
Two thousand nine hundred and thirty-one tri- and tetranucleotide short tandem repeat polymorphisms (STRPs) developed by the Cooperative Human Linkage Center were assigned to chromosomes using the NIGMS somatic cell hybrid mapping panel 2 and an efficient pooling strategy. Approximately 82% of all STRPs tested were assigned by this method, with 96.7% accuracy. Many of the single chromosome cell lines contained portions of additional chromosomes, confirming previous reports. The cell lines for chromosomes 6, 14, and 20 contained extensive portions of other chromosomes. Five previously unreported chromosomal contaminants were identified and are reported. A new pooling strategy was designed to minimize ambiguous assignments.
Asunto(s)
Mapeo Cromosómico/métodos , Marcadores Genéticos , Repeticiones de Microsatélite , Repeticiones de Trinucleótidos , Animales , Secuencia de Bases , Línea Celular , Bandeo Cromosómico , Cromosomas Humanos/genética , Cricetinae , Femenino , Humanos , Células Híbridas , Masculino , RatonesRESUMEN
We developed a simple and rapid amplification-refractory mutation system (ARMS) assay for the factor V mutation [R506Q] (factor VLeiden), which results in the autosomal dominant thrombotic tendency, resistance to activated protein C (rAPC). PCR primers within Exon 10 of the factor V gene were designed. A common upstream primer was paired with either a mutant or wild-type-specific downstream primer. The 3'-most nucleotide of the specific primers recognized either the mutant or normal allele, and the 3' penultimate nucleotide was mismatched to enhance specificity of the reaction. The assay was validated using authentic factor VLeiden DNA samples. Seven of 103 hematologically normal children (6.8%) were found to be heterozygotes. Among 27 patients studied by the rAPC assay, ARMS assay and rAPC results were concordant in 26. Among these were a 1-year-old child with a calcified clot in the inferior vena cava. Both the patient and his father were heterozygous for the mutation and both had abnormal rAPC assays. rAPC and factor VLeiden assays were discordant in a young girl with a history of stroke. Biochemical rAPC assay was abnormal, while ARMS assay revealed amplification only with wild-type primers, suggesting a non-[R506Q] mechanism for rAPC. This assay will be a valuable tool for studying subjects with thromboses and their family members.