RESUMEN

High-temperature-requirement protein A (HtrA) family proteins play important roles in controlling protein quality and are recognized as virulence factors in numerous animal and human bacterial pathogens. The role of HtrA family proteins in plant pathogens remains largely unexplored. Here, we investigated the HtrA family protein, DegQ, in the crucifer black rot pathogen Xanthomonas campestris pathovar campestris (Xcc). DegQ is essential for bacterial attachment and full virulence of Xcc. Moreover, the degQ mutant strain showed increased sensitivity to heat treatment and sodium dodecyl sulfate. Expressing the intact degQ gene in trans in the degQ mutant could reverse the observed phenotypic changes. In addition, we demonstrated that the DegQ protein exhibited chaperone-like activity. Transcriptional analysis displayed that degQ expression was induced under heat treatment. Our results contribute to understanding the function and expression of DegQ of Xcc for the first time and provide a novel perspective about HtrA family proteins in plant pathogen.

Asunto(s)

Proteínas Bacterianas , Regulación Bacteriana de la Expresión Génica , Enfermedades de las Plantas , Xanthomonas campestris , Xanthomonas campestris/genética , Xanthomonas campestris/patogenicidad , Xanthomonas campestris/metabolismo , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Enfermedades de las Plantas/microbiología , Virulencia/genética , Factores de Virulencia/genética , Factores de Virulencia/metabolismo , Calor , Adhesión Bacteriana/genética , Dodecil Sulfato de Sodio/farmacología , Chaperonas Moleculares/genética , Chaperonas Moleculares/metabolismo , Brassica/microbiología , Perfilación de la Expresión Génica , Mutación

RESUMEN

SsrA and SmpB are known to play important roles in translational quality control and are essential for virulence in many human and animal pathogenic bacteria. The physiological roles and contribution of SsrA and SmpB to plant pathogen are unclear. Here, we present evidence to show that ssrA and smpB are involved in pathogenesis of Xanthomonas campestris pathovar campestris, the cause of black rot diseases in crucifers. The ssrA and smpB mutants exhibited defects in bacterial attachment, cell motility, and extracellular enzyme activity. The mutation of ssrA and smpB also resulted in a reduction in temperature tolerance. These altered phenotypes of the ssrA and smpB mutants could be complemented to wild-type levels by the intact ssrA and smpB genes. This is the first demonstration of the roles of SsrA and SmpB in phytopathogen.

Asunto(s)

Xanthomonas campestris , Animales , Humanos , Xanthomonas campestris/genética , Proteínas Bacterianas/genética , Virulencia/genética , Factores de Virulencia/genética , Proteómica , Enfermedades de las Plantas/microbiología

RESUMEN

ATP-dependent proteases (FtsH, Lon, and Clp family proteins) are ubiquitous in bacteria and play essential roles in numerous regulatory cell processes. Xanthomonas campestris pv. campestris is a Gram-negative pathogen that can cause black rot diseases in crucifers. The genome of X. campestris pv. campestris has several clp genes, namely, clpS, clpA, clpX, clpP, clpQ, and clpY. Among these genes, only clpX and clpP is known to be required for pathogenicity. Here, we focused on two uncharacterized clp genes (clpS and clpA) that encode the adaptor (ClpS) and ATPase subunit (ClpA) of the ClpAP protease complex. Transcriptional analysis revealed that the expression of clpS and clpA was growth phase-dependent and affected by the growth temperature. The inactivation of clpA, but not of clpS, resulted in susceptibility to high temperature and attenuated virulence in the host plant. The altered phenotypes of the clpA mutant could be complemented in trans. Site-directed mutagenesis revealed that K223 and K504 were the amino acid residues critical for ClpA function in heat tolerance. The protein expression profile shown by the clpA mutant in response to heat stress was different from that exhibited by the wild type. In summary, we characterized two clp genes (clpS and clpA) by examining their expression profiles and functions in different processes, including stress tolerance and pathogenicity. We demonstrated that clpS and clpA were expressed in a temperature-dependent manner and that clpA was required for the survival at high temperature and full virulence of X. campestris pv. campestris. This work represents the first time that clpS and clpA were characterized in Xanthomonas.

Asunto(s)

Xanthomonas campestris , Adenosina Trifosfatasas/metabolismo , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Virulencia/genética , Xanthomonas campestris/genética , Xanthomonas campestris/metabolismo

RESUMEN

BACKGROUND: Xanthomonas campestris pv. campestris (Xcc) is a Gram-negative bacterium that can cause black rot disease in crucifers. The lipoprotein outer membrane localization (Lol) system is involved in the lipoprotein sorting to the outer membrane. Although Xcc has a set of annotated lol genes, there is still little known about the physiological role in this phytopathogen. In this study, we aimed to characterize the role of LolB of Xcc in bacterial attachment, stress tolerance, and virulence. RESULTS: To characterize the role of LolB, lolB mutant was constructed and phenotypic evaluation was performed. The lolB mutant revealed reductions in bacterial attachment, extracellular enzyme production, and virulence. Mutation of lolB also resulted in reduced tolerance to a myriad of stresses, including heat and a range of membrane-perturbing agents. Trans-complementation of lolB mutant with intact lolB gene reverted these altered phenotypes to the wild-type levels. From subsequent reporter assay and reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR) analysis, the expression of genes that encode the major extracellular enzymes and the stress-related proteins was reduced after lolB mutation. CONCLUSIONS: The results in this work contribute to the functional understanding of lolB in Xanthomonas for the first time, and provide new insights into the function of lolB in bacteria.

Asunto(s)

Proteínas de la Membrana Bacteriana Externa/genética , Xanthomonas campestris/fisiología , Xanthomonas campestris/patogenicidad , Adaptación Fisiológica/genética , Adhesión Bacteriana/genética , Membrana Celular/genética , Membrana Celular/metabolismo , Regulación Bacteriana de la Expresión Génica/genética , Lipoproteínas/genética , Lipoproteínas/metabolismo , Mutación , Enfermedades de las Plantas/microbiología , Virulencia/genética , Xanthomonas campestris/genética , Xanthomonas campestris/metabolismo

RESUMEN

Purpose: To determine the prevalence, clinical manifestations, and treatment outcomes of IgG4-related ophthalmic disease (IgG4-ROD) in previously diagnosed idiopathic orbital inflammation (IOI).Materials and Methods: Thirty one surgically treated patients with IOI between 1990 and 2015 were divided into sclerosing (SIOI) and non-sclerosing (NSIOI) to identify IgG4-ROD. Preserved pathological specimens were immunostained for IgG4 cells. Changes in clinical features were evaluated before and after treatment.Results: Out of the 31 patients, 15 (48.4%) had IgG4-ROD, consisting of 7 of the 16 SIOI (43.8%) and 8 of the 15 NSIOI patients (53.3%). Among 15 patients with IgG4-ROD, 4 (26.7%) achieved complete remission, which was significantly less than among IgG4-unrelated patients (11/16, 68.8%, p = .03). Furthermore, 3 out of 15 IgG4-ROD patients (20%) experienced recurrence, all of whom had SIOI, compared to 0% among IgG4-unrelated patients (p = .1).Conclusions: IgG4-ROD is common among previously identified IOI in our study. Treatment response is modest in IgG4-ROD patients.

Asunto(s)

Enfermedades Autoinmunes/diagnóstico , Predicción , Inmunoglobulina G/inmunología , Miositis Orbitaria/diagnóstico , Seudotumor Orbitario/diagnóstico , Enfermedades Autoinmunes/inmunología , Estudios de Seguimiento , Humanos , Inmunohistoquímica , Miositis Orbitaria/inmunología , Estudios Retrospectivos

RESUMEN

BACKGROUND: Sebaceous tumors are adnexal neoplasms showing sebocytic differentiation. They range from benign to malignant and are associated with Muir-Torre syndrome (MTS). Several clinical and histopathological features associated with MTS have been described. Sebaceous tumors with an overlying cutaneous horn are extremely rare. METHODS: Hematoxylin and eosin-stained slides were retrospectively reviewed to identify sebaceous tumors with marked hyperkeratosis, a condition that is often associated with cutaneous horns. Clinical correlation and mismatch repair protein immunohistochemical studies were then conducted. RESULTS: Four tumors from three patients were identified in our archive. Three were classified as sebaceous adenomas, and the fourth was considered as a borderline sebaceous tumor favoring well-differentiated sebaceous carcinoma. All cases showed loss of expression of mismatch repair proteins (three tumors from two patients exhibited lost expression of MSH2 and MSH6, and the fourth exhibited lost expression of MLH1 and PMS2). Additionally, one patient presented characteristic clinical manifestations of MTS, including multiple sebaceous adenomas and visceral carcinomas. CONCLUSIONS: We suggest that extraocular well-differentiated sebaceous neoplasms with overlying cutaneous horns may be an indication of underlying mismatch repair protein deficiency and potential MTS. This distinctive morphology might be an exaggerated combination of other features associated with MTS, i.e. keratoacanthoma-like architecture and extensive holocrine secretion.

Asunto(s)

Adenoma/patología , Carcinoma/patología , Neoplasias de las Glándulas Sebáceas/patología , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Síndrome de Muir-Torre/complicaciones

RESUMEN

Periocular sebaceous carcinoma is an aggressive neoplasm with significant morbidity and mortality. Its pathogenesis is poorly understood. It is only rarely associated with Muir-Torre syndrome. Previous studies from Asian countries, have suggested that human papillomavirus (HPV) infection plays a role in the pathogenesis and overexpression of p16(INK4a), a surrogate marker of HPV infection, have also been reported. However, data from western countries seem contradictory. In order to clarify and explore the molecular and epigenetic basis of HPV, CDKN2A status and role of microsatellite instability in the development of periocular sebaceous carcinoma, 24 cases of periocular sebaceous carcinoma were analyzed for the expression of p16(INK4a) and mismatch repair proteins (MLH1, MSH2, MSH6 and PMS2) via immunohistochemistry. Nested polymerase chain reaction (PCR) and genechip HPV typing were used to detect HPV infection and decide its genotype when present. PCR amplification using a consensus primer pair was also performed to detect ß-HPV. The methylation status of CDKN2A promoter region was studied by methylation-specific polymerase chain reaction. HPV-positivity was demonstrated in only one of our cases (HPV 16), while another case showed p16(INK4a) overexpression. All cases showed preserved expression of mismatch repair proteins. CDKN2A promoter hypermethylation was noted in nearly half of our cases (11/24) and was associated with younger patient age (P = .013). Our results showed that periocular sebaceous carcinoma is rarely associated with HPV and microsatellite instability. Higher frequency of CDKN2A promoter hypermethylation in younger patients implies a significant epigenetic role in tumor development in this age group.

Asunto(s)

Carcinoma/genética , Inhibidor p16 de la Quinasa Dependiente de Ciclina/genética , Metilación de ADN , Neoplasias de los Párpados/genética , Regiones Promotoras Genéticas , Neoplasias de las Glándulas Sebáceas/genética , Factores de Edad , Anciano , Anciano de 80 o más Años , Biomarcadores de Tumor/genética , Biomarcadores de Tumor/metabolismo , Carcinoma/metabolismo , Carcinoma/patología , Carcinoma/virología , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/patología , Carcinoma de Células Escamosas/virología , Inhibidor p16 de la Quinasa Dependiente de Ciclina/metabolismo , Epigénesis Genética , Neoplasias de los Párpados/metabolismo , Neoplasias de los Párpados/patología , Neoplasias de los Párpados/virología , Femenino , Humanos , Masculino , Inestabilidad de Microsatélites , Persona de Mediana Edad , Papillomaviridae , Infecciones por Papillomavirus/genética , Infecciones por Papillomavirus/patología , Neoplasias de las Glándulas Sebáceas/metabolismo , Neoplasias de las Glándulas Sebáceas/patología , Neoplasias de las Glándulas Sebáceas/virología , Neoplasias del Cuello Uterino/genética , Neoplasias del Cuello Uterino/patología , Neoplasias del Cuello Uterino/virología

RESUMEN

Human monitoring performance was compared for different screens within a single display. Participants' performance with random signals and different numbers of split screens was tested for a period of time. The performance measures were hit rate, false alarm rate, and response time. Results indicated that the response time and false alarm rate significantly increased with the number of split screens. Results also showed that signal frequency significantly influenced the false alarm rate. The location of the 9-screen display was analyzed on hit rate and false alarm rate. More attention was paid to the center screen as indicated by both the higher hit rate and false alarm rate. Findings suggest that designers of monitoring systems should take into consideration the trade-off between the number of multiple split screens and the limited human capability for monitoring performance. Furthermore, it is suggested that high risk and critical information should be placed in the center region to be detected effectively.

Asunto(s)

Desempeño Psicomotor/fisiología , Detección de Señal Psicológica/fisiología , Adulto , Análisis de Varianza , Atención/fisiología , Femenino , Humanos , Masculino , Pruebas Neuropsicológicas , Estimulación Luminosa , Tiempo de Reacción/fisiología

RESUMEN

BACKGROUND: Oral squamous cell carcinoma (OSCC) is one of the leading cancers in most Asian countries. Alterations of immune function have been detected in OSCC patients. The pro-inflammatory cytokine tumor necrosis factor-alpha (TNF-alpha) is a central mediator of the immune response involved in a wide range of immuno-inflammatory and infectious diseases. Polymorphism of the TNF-alpha gene has been intensively studied as a potential determinant of susceptibility to numerous cancers. METHODS: We genotyped 192 patients with OSCC and 146 healthy case controls by using polymerase chain reaction-double restriction fragment length polymorphism with amplification-created restriction sites to assess allelic determinants at the TNF-alpha polymorphic sites -308 and -238 in the promoter region. Genotype frequencies were evaluated with Fisher's test. RESULTS: The -308 TNFG (tumor necrosis factor G) allele genotype was higher in patients with OSCC (91.2% vs. 82.2%; P = 0.02) and TNFG/A was lower (8.3% vs. 11.8%; P = 0.02); the -238 TNFG/A allele genotype was lower in patient with OSCC (2.1% vs. 6.9%; P = 0.02). CONCLUSION: This is the first report that the TNF-alpha polymorphism is associated with the risk for OSCC in Taiwan.

Asunto(s)

Carcinoma de Células Escamosas/genética , Predisposición Genética a la Enfermedad/genética , Neoplasias de la Boca/genética , Polimorfismo Genético/genética , Regiones Promotoras Genéticas/genética , Factor de Necrosis Tumoral alfa/genética , Adenina , Alelos , Secuencia de Bases , Estudios de Casos y Controles , Femenino , Frecuencia de los Genes , Genotipo , Guanina , Humanos , Masculino , Persona de Mediana Edad , Reacción en Cadena de la Polimerasa , Polimorfismo de Longitud del Fragmento de Restricción

RESUMEN

Oral squamous cell carcinoma (OSCC) is a worldwide disease. In South Asians, the high prevalence of OSCC is tightly linked to areca chewing. The prognosis for OSCC remains dismal and improvement in early diagnosis may benefit the survival of patients with this disease. Chromosome region 3q26-27 has been shown to carry several oncogenes. By quantitative PCR (Q-PCR), the gene copy numbers of TERC, PI3KCA, ZASC1, and TP63 from microdissected OSCCs have been determined. Copy number amplifications of PI3KCA and ZASC1, a newly identified zinc finger transcription factor, were identified in 30 (65%) and 32 (70%) of 46 primary OSCCs, respectively. Co-amplification of PI3KCA and ZASC1 in 50% of primary OSCCs suggests that they are critical targets of the 3q26.3 amplicon. OSCCs carrying higher levels of PI3KCA and/or ZASC1 copy number amplification were associated with a significantly higher propensity for lymph node metastasis. ZASC1 mRNA expression in OSCC was also associated with lymph node metastasis. In addition, copy number amplification of at least one 3q26-27 oncogene was detected in brush samples from 10 of 22 (45%) patients with oral leukoplakia and 5 of 20 (25%) oral mucosa samples from areca chewers without a visible lesion. These data indicate frequent copy number amplification and overexpression of ZASC1 in OSCC. The findings also suggest the potential use of Q-PCR analysis and brush collection of samples to dissect OSCC risk.

Asunto(s)

Carcinoma de Células Escamosas/genética , Neoplasias de la Boca/genética , Proteínas de Neoplasias/genética , Oncogenes/genética , Adulto , Areca/efectos adversos , Proteínas Portadoras/genética , Células Cultivadas , Proteínas de Unión al ADN , Femenino , Amplificación de Genes/genética , Genes Supresores de Tumor , Neoplasias de Cabeza y Cuello/secundario , Humanos , Metástasis Linfática/genética , Masculino , Persona de Mediana Edad , Mucosa Bucal/química , Proteínas Nucleares/genética , Fosfoproteínas/genética , ARN/genética , ARN Mensajero/genética , Telomerasa/genética , Transactivadores/genética , Factores de Transcripción/genética , Proteínas Supresoras de Tumor

Asunto(s)

Neoplasias Encefálicas/diagnóstico , Quiste Dermoide/diagnóstico , Exotropía/diagnóstico , Neoplasias Encefálicas/complicaciones , Neoplasias Encefálicas/cirugía , Seno Cavernoso/patología , Niño , Quiste Dermoide/complicaciones , Quiste Dermoide/cirugía , Exotropía/etiología , Humanos , Imagen por Resonancia Magnética , Masculino , Enfermedades del Nervio Oculomotor/diagnóstico , Enfermedades del Nervio Oculomotor/etiología