RESUMEN
The role of gut microbiota in host defense against nontuberculous mycobacterial lung disease (NTM-LD) was poorly understood. Here, we showed significant gut microbiota dysbiosis in patients with NTM-LD. Reduced abundance of Prevotella copri was significantly associated with NTM-LD and its disease severity. Compromised TLR2 activation activity in feces and plasma in the NTM-LD patients was highlighted. In the antibiotics-treated mice as a study model, gut microbiota dysbiosis with reduction of TLR2 activation activity in feces, sera, and lung tissue occurred. Transcriptomic analysis demonstrated immunocompromised in lung which were closely associated with increased NTM-LD susceptibility. Oral administration of P. copri or its capsular polysaccharides enhanced TLR2 signaling, restored immune response, and ameliorated NTM-LD susceptibility. Our data highlighted the association of gut microbiota dysbiosis, systematically compromised immunity and NTM-LD development. TLR2 activation by P. copri or its capsular polysaccharides might help prevent NTM-LD.
Asunto(s)
Disbiosis , Microbioma Gastrointestinal , Infecciones por Mycobacterium no Tuberculosas , Receptor Toll-Like 2 , Disbiosis/microbiología , Animales , Receptor Toll-Like 2/metabolismo , Receptor Toll-Like 2/genética , Humanos , Ratones , Masculino , Femenino , Infecciones por Mycobacterium no Tuberculosas/microbiología , Persona de Mediana Edad , Heces/microbiología , Anciano , Prevotella , Enfermedades Pulmonares/microbiología , Micobacterias no Tuberculosas , Susceptibilidad a Enfermedades , Ratones Endogámicos C57BL , Pulmón/microbiologíaRESUMEN
Nosocomial infectious outbreaks caused by multidrug-resistant Acinetobacter baumannii have emerged as a serious threat to human health. Phosphoproteomics of pathogenic bacteria has been used to identify the mechanisms of bacterial virulence and antimicrobial resistance. In this study, we used a shotgun strategy combined with high-accuracy mass spectrometry to analyze the phosphoproteomics of the imipenem-susceptible strain SK17-S and -resistant strain SK17-R. We identified 410 phosphosites on 248 unique phosphoproteins in SK17-S and 285 phosphosites on 211 unique phosphoproteins in SK17-R. The distributions of the Ser/Thr/Tyr/Asp/His phosphosites in SK17-S and SK17-R were 47.0%/27.6%/12.4%/8.0%/4.9% versus 41.4%/29.5%/17.5%/6.7%/4.9%, respectively. The Ser-90 phosphosite, located on the catalytic motif S(88)VS(90)K of the AmpC ß-lactamase, was first identified in SK17-S. Based on site-directed mutagenesis, the nonphosphorylatable mutant S90A was found to be more resistant to imipenem, whereas the phosphorylation-simulated mutant S90D was sensitive to imipenem. Additionally, the S90A mutant protein exhibited higher ß-lactamase activity and conferred greater bacterial protection against imipenem in SK17-S compared with the wild-type. In sum, our results revealed that in A. baumannii, Ser-90 phosphorylation of AmpC negatively regulates both ß-lactamase activity and the ability to counteract the antibiotic effects of imipenem. These findings highlight the impact of phosphorylation-mediated regulation in antibiotic-resistant bacteria on future drug design and new therapies.
Asunto(s)
Acinetobacter baumannii/efectos de los fármacos , Proteínas Bacterianas/metabolismo , Imipenem/farmacología , Proteoma/metabolismo , Proteómica/métodos , beta-Lactamasas/metabolismo , Acinetobacter baumannii/genética , Acinetobacter baumannii/metabolismo , Antibacterianos/farmacología , Proteínas Bacterianas/química , Proteínas Bacterianas/genética , Sitios de Unión/genética , Infección Hospitalaria/microbiología , Humanos , Modelos Moleculares , Mutación , Fosfoproteínas/metabolismo , Fosforilación , Estructura Terciaria de Proteína , Espectrometría de Masas en Tándem , Resistencia betalactámica/efectos de los fármacos , beta-Lactamasas/química , beta-Lactamasas/genéticaRESUMEN
Lung cancer is a common malignancy and has a poor overall prognosis. Widespread metastasis is a common phenomenon in non-small cell lung cancer (NSCLC). It has been demonstrated that cancer relapse and survival can be predicted by the presence of a five-microRNA (miRNA) signature independent of stage or histologic type in NSCLC patients. Among the five miRNAs in the signature, miR-372 has been shown to play a significant role in metastasis and in the development of human testicular germ cell tumors. In addition, there is evidence that miR-372 posttranscriptionally downregulates large tumor suppressor, homolog 2 (Lats2), resulting in tumorigenesis and proliferation. To further investigate the cellular mechanisms involved in miR-372-induced silencing, we conducted a comparative proteomic analysis of NSCLC CL 1-0 cells expressing miRNA-372 and/or vector only by using two-dimensional gel electrophoresis (2DE), two-dimensional difference gel electrophoresis (2D-DIGE), and LC/MS/MS. Proteins identified as being up- or downregulated were further classified according to their biological functions. Many of the proteins identified in our study may be potential diagnostic biomarkers of NSCLC, particularly phosphorylated eIF4A-I.
