RESUMEN
Serratia marcescens swarms on 0.8% LB agar at 30 °C but not at 37 °C. To understand the molecular mechanism regulating Serratia swarming, transposon mutagenesis was performed to screen for mutants that swarmed at 37 °C. In one mutant, S. marcescens WW100, the transposon was inserted in the upstream region of manA, which encodes mannose-6-phosphate isomerase, a type I phosphomannose isomerase. The transcriptional and translational levels of manA were higher in S. marcescens WW100 than in the wild-type strain. S. marcescens WW100 produced more serrawettin W1 (biosurfactant) than the wild-type, as detected by thin-layer chromatography, to promote surface motility by reducing surface tension. Serratia swarming was previously shown to be negatively regulated by the RssA-RssB two-component system. An electrophoretic mobility shift assay (EMSA) indicated that phosphorylated RssB (the response regulator) binds upstream of the transposon insertion site and manA in S. marcescens WW100. Analysis by real-time RT-PCR (qRT-PCR) revealed that, compared to the wild-type level, manA mRNA was increased in the rssA deletion mutant. The results indicated that RssA-RssB signaling directly represses the expression of manA and that overexpression of manA increases the production of serrawettin for Serratia swarming at 37 °C.
Asunto(s)
Proteínas Bacterianas/metabolismo , Manosa-6-Fosfato Isomerasa/metabolismo , Serratia marcescens/fisiología , Transducción de Señal , Secuencia de Bases , Sitios de Unión , Elementos Transponibles de ADN , Regulación Bacteriana de la Expresión Génica , Glucosa/metabolismo , Manosa/metabolismo , Manosa-6-Fosfato Isomerasa/genética , Redes y Vías Metabólicas , Datos de Secuencia Molecular , Mutagénesis , Unión ProteicaRESUMEN
OBJECTIVES: A germline BIM deletion polymorphism has been proposed to predict a poor treatment efficacy of certain kinase inhibitors. The current study aimed to explore whether the BIM deletion polymorphism predicts the treatment efficacy of sorafenib for advanced hepatocellular carcinoma (HCC). METHODS: All patients who were enrolled in clinical trials to receive sorafenib-containing regimens as first-line therapy for advanced HCC and consented to providing peripheral blood samples were included. Polymerase chain reaction followed by gel electrophoresis was used to detect the germline BIM deletion polymorphism. RESULTS: A total of 89 patients were enrolled; 69 (77%) patients had chronic hepatitis B infection, and 18 (20%) had chronic hepatitis C infection. The heterozygous BIM deletion polymorphism was identified in 9 (10%) patients. Patients with and without the BIM deletion polymorphism had similar response rates (11 vs. 6%) and disease control rates (56 vs. 61%). The time to progression, progression-free survival, and overall survival were similar between patients with and without the BIM deletion polymorphism. After adjusting for basic clinicopathologic variables and treatment regimens, the BIM polymorphism still could not predict treatment outcomes. CONCLUSIONS: The BIM deletion polymorphism was not associated with the treatment efficacy of sorafenib for advanced HCC.
Asunto(s)
Antineoplásicos/uso terapéutico , Proteínas Reguladoras de la Apoptosis/genética , Carcinoma Hepatocelular/tratamiento farmacológico , Carcinoma Hepatocelular/genética , Eliminación de Gen , Mutación de Línea Germinal , Neoplasias Hepáticas/tratamiento farmacológico , Neoplasias Hepáticas/genética , Proteínas de la Membrana/genética , Niacinamida/análogos & derivados , Compuestos de Fenilurea/uso terapéutico , Polimorfismo de Nucleótido Simple , Proteínas Proto-Oncogénicas/genética , Adulto , Anciano , Proteína 11 Similar a Bcl2 , Carcinoma Hepatocelular/mortalidad , Supervivencia sin Enfermedad , Femenino , Genotipo , Humanos , Estimación de Kaplan-Meier , Neoplasias Hepáticas/mortalidad , Masculino , Persona de Mediana Edad , Niacinamida/uso terapéutico , Valor Predictivo de las Pruebas , Inhibidores de Proteínas Quinasas/uso terapéutico , Sorafenib , Resultado del TratamientoRESUMEN
Rapid assays are still needed to detect rifabutin (RFB) susceptibility for proper tuberculosis treatment. To assess the use of the GenoType MTBDRplus assay and subsequent rpoB gene sequencing on detection of RFB susceptibility, we analyzed 800 multidrug-resistant Mycobacterium tuberculosis isolates, and 13% (104/800) were RFB susceptible. Of the 104 RFB-susceptible isolates, 71 (68.3%) isolates were rapidly identified using two molecular assays, while the remaining isolates could be determined using conventional drug-susceptibility testing according to the clinician's decision.
Asunto(s)
Antituberculosos/farmacología , Técnicas de Diagnóstico Molecular/métodos , Mycobacterium tuberculosis/efectos de los fármacos , Rifabutina/farmacología , Tuberculosis Resistente a Múltiples Medicamentos/microbiología , ARN Polimerasas Dirigidas por ADN/genética , Farmacorresistencia Bacteriana Múltiple , Humanos , Pruebas de Sensibilidad Microbiana/métodos , Mycobacterium tuberculosis/genéticaRESUMEN
Widely identified in bacteria, yeasts and human beings, 2,3-butanediol has been studied for decades. This chemical reportedly functions as a neutralization agent to counteract lethal acidification by bacterial growth and as a signaling molecule involved in interactions among insects, and between bacteria and the plant host. While 2,3-butanediol is produced by many pathogenic bacterial species, its significance and effect on mammals remains basically uncharacterized. Herein, we show that gastric intubation of 2,3-butanediol in rats significantly ameliorates acute lung injury (ALI) and the inflammatory responses induced by the bacterial endotoxin lipopolysaccharide (LPS), with an efficacy comparable to that of the polyphenol compound resveratrol. Such effect was further demonstrated to occur via modulation of the NF-kappaB signaling pathway. These results indicate that bacterial metabolite, 2,3-butanediol has a negative regulatory effect on host innate immunity response, suggesting bacteria may use some metabolites for host immune evasion.
Asunto(s)
Antiinflamatorios/administración & dosificación , Butileno Glicoles/administración & dosificación , Endotoxinas/toxicidad , Inflamación/tratamiento farmacológico , Lipopolisacáridos/toxicidad , Pulmón/efectos de los fármacos , Pulmón/patología , Animales , Endotoxinas/administración & dosificación , Inflamación/inmunología , Inflamación/patología , Lipopolisacáridos/administración & dosificación , Pulmón/inmunología , Masculino , FN-kappa B/metabolismo , Ratas , Ratas Sprague-Dawley , Transducción de Señal , Resultado del TratamientoRESUMEN
The protein pirin, which is involved in a variety of biological processes, is conserved from prokaryotic microorganisms, fungi, and plants to mammals. It acts as a transcriptional cofactor or an apoptosis-related protein in mammals and is involved in seed germination and seedling development in plants. In prokaryotes, while pirin is stress induced in cyanobacteria and may act as a quercetinase in Escherichia coli, the functions of pirin orthologs remain mostly uncharacterized. We show that the Serratia marcescens pirin (pirin(Sm)) gene encodes an ortholog of pirin protein. Protein pull-down and bacterial two-hybrid assays followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and electrospray ionization-tandem mass spectrometry analyses showed the pyruvate dehydrogenase (PDH) E1 subunit as a component interacting with the pirin(Sm) gene. Functional analyses showed that both PDH E1 subunit activity and PDH enzyme complex activity are inhibited by the pirin(Sm) gene in S. marcescens CH-1. The S. marcescens CH-1 pirin(Sm) gene was subsequently mutated by insertion-deletion homologous recombination. Accordingly, the PDH E1 and PDH enzyme complex activities and cellular ATP concentration increased up to 250%, 140%, and 220%, respectively, in the S. marcescens CH-1 pirin(Sm) mutant. Concomitantly, the cellular NADH/NAD(+) ratio increased in the pirin(Sm) mutant, indicating increased tricarboxylic acid (TCA) cycle activity. Our results show that the pirin(Sm) gene plays a regulatory role in the process of pyruvate catabolism to acetyl coenzyme A through interaction with the PDH E1 subunit and inhibiting PDH enzyme complex activity in S. marcescens CH-1, and they suggest that pirin(Sm) is an important protein involved in determining the direction of pyruvate metabolism towards either the TCA cycle or the fermentation pathways.