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1.
RNA ; 27(12): 1557-1576, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34544891

RESUMO

The regulation of pre-mRNA processing has important consequences for cell division and the control of cancer cell proliferation, but the underlying molecular mechanisms remain poorly understood. We report that three splicing factors, SPF45, SR140, and CHERP, form a tight physical and functionally coherent complex that regulates a variety of alternative splicing events, frequently by repressing short exons flanked by suboptimal 3' splice sites. These comprise alternative exons embedded in genes with important functions in cell-cycle progression, including the G2/M key regulator FOXM1 and the spindle regulator SPDL1. Knockdown of either of the three factors leads to G2/M arrest and to enhanced apoptosis in HeLa cells. Promoting the changes in FOXM1 or SPDL1 splicing induced by SPF45/SR140/CHERP knockdown partially recapitulates the effects on cell growth, arguing that the complex orchestrates a program of alternative splicing necessary for efficient cell proliferation.


Assuntos
Processamento Alternativo , Proteínas de Ciclo Celular/metabolismo , Proteínas de Ligação a DNA/metabolismo , Regulação Neoplásica da Expressão Gênica , Proteínas de Membrana/metabolismo , Fatores de Processamento de RNA/metabolismo , Proteínas de Ligação a RNA/metabolismo , Ribonucleoproteínas/metabolismo , Neoplasias do Colo do Útero/patologia , Apoptose , Proteínas de Ciclo Celular/genética , Proliferação de Células , Proteínas de Ligação a DNA/genética , Feminino , Células HeLa , Humanos , Proteínas de Membrana/genética , Fatores de Processamento de RNA/genética , Proteínas de Ligação a RNA/genética , Ribonucleoproteínas/genética , Neoplasias do Colo do Útero/genética , Neoplasias do Colo do Útero/metabolismo
2.
Endoscopy ; 54(1): 27-34, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-33271604

RESUMO

BACKGROUND: The "diagnose-and-leave-in" policy has been established to reduce the risks and costs related to unnecessary polypectomies in the average-risk population. In individuals with Lynch syndrome, owing to accelerated carcinogenesis, the general recommendation is to remove all polyps, irrespective of size, location, and appearance. We evaluated the feasibility and safety of the diagnose-and-leave-in strategy in individuals with Lynch syndrome. METHODS : We performed a post hoc analysis based on per-polyp data from a randomized, clinical trial conducted by 24 dedicated colonoscopists at 14 academic centers, in which 256 patients with confirmed Lynch syndrome underwent surveillance colonoscopy from July 2016 to January 2018. In vivo optical diagnosis with confidence level for all detected lesions was obtained before polypectomy using virtual chromoendoscopy alone or with dye-based chromoendoscopy. Primary outcome was the negative predictive value (NPV) for neoplasia of high-confidence optical diagnosis among diminutive (≤ 5 mm) rectosigmoid lesions. Histology was the reference standard. RESULTS: Of 147 rectosigmoid lesions, 128 were diminutive. In 103 of the 128 lesions (81 %), the optical diagnostic confidence was high and showed an NPV of 96.0 % (95 % confidence interval [CI] 88.9 %-98.6 %) and accuracy of 89.3 % (95 %CI 81.9 %-93.9 %). By following the diagnose-and-leave-in policy, we would have avoided 59 % (75/128) of polypectomies at the expense of two diminutive low grade dysplastic adenomas and one diminutive sessile serrated lesion that would have been left in situ. CONCLUSION: In patients with Lynch syndrome, the diagnose-and-leave-in strategy for diminutive rectosigmoid polyps would be feasible and safe.


Assuntos
Pólipos do Colo , Neoplasias Colorretais Hereditárias sem Polipose , Neoplasias Colorretais , Pólipos do Colo/diagnóstico por imagem , Pólipos do Colo/cirurgia , Colonoscopia , Neoplasias Colorretais Hereditárias sem Polipose/diagnóstico , Humanos , Imagem de Banda Estreita
3.
Gastroenterology ; 158(4): 895-904.e1, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31520613

RESUMO

BACKGROUND & AIMS: Dye-based pancolonic chromoendoscopy is recommended for colorectal cancer surveillance in patients with Lynch syndrome. However, there is scarce evidence to support its superiority to high-definition white-light endoscopy. We performed a prospective study assess whether in the hands of high detecting colonoscopists, high-definition, white-light endoscopy is noninferior to pancolonic chromoendoscopy for detection of adenomas in patients with Lynch syndrome. METHODS: We conducted a parallel controlled study, from July 2016 through January 2018 at 14 centers in Spain of adults with pathogenic germline variants in mismatch repair genes (60% women; mean age, 47 ± 14 years) under surveillance. Patients were randomly assigned to groups that underwent high-definition white-light endoscopy (n = 128) or pancolonic chromoendoscopy (n = 128) evaluations by 24 colonoscopists who specialized in detection of colorectal lesions in high-risk patients for colorectal cancer. Adenoma detection rates (defined as the proportion of patients with at least 1 adenoma) were compared between groups, with a noninferiority margin (relative difference) of 15%. RESULTS: We found an important overlap of confidence intervals (CIs) and no significant difference in adenoma detection rates by pancolonic chromoendoscopy (34.4%; 95% CI 26.4%-43.3%) vs white-light endoscopy (28.1%; 95% CI 21.1%-36.4%; P = .28). However, pancolonic chromoendoscopy detected serrated lesions in a significantly higher proportion of patients (37.5%; 95% CI 29.5-46.1) than white-light endoscopy (23.4%; 95% CI 16.9-31.4; P = .01). However, there were no significant differences between groups in proportions of patients found to have serrated lesions of 5 mm or larger (9.4% vs 7.0%; P = .49), of proximal location (11.7% vs 10.2%; P = .68), or sessile serrated lesions (3.9% vs 5.5%; P = .55), respectively. Total procedure and withdrawal times with pancolonic chromoendoscopy (30.7 ± 12.8 minutes and 18.3 ± 7.6 minutes, respectively) were significantly longer than with white-light endoscopy (22.4 ± 8.7 minutes and 13.5 ± 5.6 minutes; P < .001). CONCLUSIONS: In a randomized parallel trial, we found that for Lynch syndrome surveillance, high-definition white-light endoscopy is not inferior to pancolonic chromoendoscopy if performed by experienced and dedicated endoscopists. ClinicalTrials.gov no: NCT02951390.


Assuntos
Adenoma/diagnóstico , Colonoscopia/métodos , Neoplasias Colorretais Hereditárias sem Polipose/complicações , Neoplasias Colorretais/diagnóstico , Detecção Precoce de Câncer/métodos , Vigilância da População/métodos , Adenoma/congênito , Adulto , Neoplasias Colorretais/congênito , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos
4.
5.
Gastroenterology ; 156(1): 75-87, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30296432

RESUMO

BACKGROUND & AIMS: T1 colorectal polyps with at least 1 risk factor for metastasis to lymph node should be treated surgically and are considered endoscopically unresectable. Optical analysis, based on the Narrow-Band Imaging International Colorectal Endoscopic (NICE) classification system, is used to identify neoplasias with invasion of the submucosa that require endoscopic treatment. We assessed the accuracy of the NICE classification, along with other morphologic characteristics, in identifying invasive polyps that are endoscopically unresectable (have at least 1 risk factor for metastasis to lymph node). METHODS: We performed a multicenter, prospective study of data collected by 58 endoscopists, from 1634 consecutive patients (examining 2123 lesions) at 17 university and community hospitals in Spain from July 2014 through June 2016. All consecutive lesions >10 mm assessed with narrow-band imaging were included. The primary end point was the accuracy of the NICE classification for identifying lesions with deep invasion, using findings from histology analysis as the reference standard. Conditional inference trees were fitted for the analysis of diagnostic accuracy. RESULTS: Of the 2123 lesions analyzed, 89 (4.2%) had features of deep invasion and 91 (4.3%) were endoscopically unresectable. The NICE classification system identified lesions with deep invasion with 58.4% sensitivity (95% CI, 47.5-68.8), 96.4% specificity (95% CI, 95.5-97.2), a positive-predictive value of 41.6% (95% CI, 32.9-50.8), and a negative-predictive value of 98.1% (95% CI, 97.5-98.7). A conditional inference tree that included all variables found the NICE classification to most accurately identify lesions with deep invasion (P < .001). However, pedunculated morphology (P < .007), ulceration (P = .026), depressed areas (P < .001), or nodular mixed type (P < .001) affected accuracy of identification. Results were comparable for identifying lesions that were endoscopically unresectable. CONCLUSIONS: In an analysis of 2123 colon lesions >10 mm, we found the NICE classification and morphologic features identify those with deep lesions with >96% specificity-even in non-expert hands and without magnification. ClinicalTrials.gov number NCT02328066.


Assuntos
Adenocarcinoma/patologia , Pólipos Adenomatosos/patologia , Pólipos do Colo/patologia , Colonoscopia/métodos , Neoplasias Colorretais/patologia , Imagem de Banda Estreita/métodos , Adenocarcinoma/classificação , Adenocarcinoma/cirurgia , Pólipos Adenomatosos/classificação , Pólipos Adenomatosos/cirurgia , Idoso , Tomada de Decisão Clínica , Pólipos do Colo/classificação , Pólipos do Colo/cirurgia , Neoplasias Colorretais/classificação , Neoplasias Colorretais/cirurgia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Invasividade Neoplásica , Estadiamento de Neoplasias , Valor Preditivo dos Testes , Estudos Prospectivos , Reprodutibilidade dos Testes , Fatores de Risco , Espanha , Carga Tumoral
6.
J Integr Plant Biol ; 62(1): 70-89, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31638740

RESUMO

The amino-terminal residue of a protein (or amino-terminus of a peptide following protease cleavage) can be an important determinant of its stability, through the Ubiquitin Proteasome System associated N-degron pathways. Plants contain a unique combination of N-degron pathways (previously called the N-end rule pathways) E3 ligases, PROTEOLYSIS (PRT)6 and PRT1, recognizing non-overlapping sets of amino-terminal residues, and others remain to be identified. Although only very few substrates of PRT1 or PRT6 have been identified, substrates of the oxygen and nitric oxide sensing branch of the PRT6 N-degron pathway include key nuclear-located transcription factors (ETHYLENE RESPONSE FACTOR VIIs and LITTLE ZIPPER 2) and the histone-modifying Polycomb Repressive Complex 2 component VERNALIZATION 2. In response to reduced oxygen or nitric oxide levels (and other mechanisms that reduce pathway activity) these stabilized substrates regulate diverse aspects of growth and development, including response to flooding, salinity, vernalization (cold-induced flowering) and shoot apical meristem function. The N-degron pathways show great promise for use in the improvement of crop performance and for biotechnological applications. Upstream proteases, components of the different pathways and associated substrates still remain to be identified and characterized to fully appreciate how regulation of protein stability through the amino-terminal residue impacts plant biology.


Assuntos
Proteínas de Plantas/metabolismo , Plantas/metabolismo , Proteólise , Ubiquitina/metabolismo , Melhoramento Vegetal , Especificidade por Substrato
7.
Clin Gastroenterol Hepatol ; 17(10): 2016-2023.e6, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-30366156

RESUMO

BACKGROUND & AIMS: Serrated polyposis syndrome (SPS), characterized by multiple and/or large proximal serrated lesions, increases the risk of colorectal cancer. Serrated lesions often are missed during colonoscopy but panchromoendoscopy can increase their detection in an average-risk population. We performed a randomized controlled study to determine the efficacy of panchromoendoscopy in detection of polyps in patients with SPS. METHODS: Patients with SPS (n = 86 patients) underwent tandem high-definition (HD) colonoscopies from February 2015 through July 2016 at 7 centers in Spain. Patients were assigned randomly to groups that received 2 HD white-light endoscopy examinations (HD-WLE group; n = 43) or HD-WLE followed by 0.4% indigo carmine panchromoendoscopy (HD-CE group; n = 43). For each procedure, polyps detected were described, removed, and analyzed by histology. The primary outcome was additional polyp detection rate, defined as the number of polyps detected during the second inspection divided by the total number of polyps detected during the first and the second examination. RESULTS: A total of 774 polyps were detected (362 in the HD-WLE group and 412 in the HD-CE group); 54.2% were hyperplastic, 13.8% were adenomas, and 10.9% were sessile serrated polyps. There was a significantly higher additional polyp detection rate in the HD-CE group (0.39; 95% CI, 0.35-0.44) than in the HD-WLE group (0.22; 95% CI, 0.18-0.27) (P < .001). A higher additional rate of serrated lesions proximal to the sigmoid colon were detected in the second inspection with HD-CE (0.40; 95% CI, 0.33-0.47) than with HD-WLE (0.24; 95% CI, 0.19-0.31) (P = .001). Detection of adenomas and serrated lesions greater than 10 mm did not differ significantly between groups. In a multivariate logistic regression analysis, only use of HD-CE was associated independently with increased polyp detection throughout the colon. CONCLUSIONS: In a randomized controlled trial, we found that panchromoendoscopy increases detection of polyps (mostly of small serrated lesions) and should be considered the standard of care in patients with SPS. Studies are needed to determine the effects of this strategy on the incidence of advanced neoplasia during long-term follow-up evaluation. ClinicalTrials.gov no: NCT03476434.


Assuntos
Pólipos Adenomatosos/diagnóstico , Pólipos do Colo/diagnóstico , Colonoscopia/métodos , Neoplasias Colorretais/diagnóstico , Corantes , Adenoma/diagnóstico , Adenoma/patologia , Pólipos Adenomatosos/patologia , Pólipos do Colo/patologia , Neoplasias Colorretais/patologia , Feminino , Humanos , Índigo Carmim , Masculino , Pessoa de Meia-Idade , Síndrome
8.
New Phytol ; 221(2): 988-1000, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30117535

RESUMO

The N-end rule pathway is a highly conserved constituent of the ubiquitin proteasome system, yet little is known about its biological roles. Here we explored the role of the N-end rule pathway in the plant immune response. We investigated the genetic influences of components of the pathway and known protein substrates on physiological, biochemical and metabolic responses to pathogen infection. We show that the glutamine (Gln) deamidation and cysteine (Cys) oxidation branches are both components of the plant immune system, through the E3 ligase PROTEOLYSIS (PRT)6. In Arabidopsis thaliana Gln-specific amino-terminal (Nt)-amidase (NTAQ1) controls the expression of specific defence-response genes, activates the synthesis pathway for the phytoalexin camalexin and influences basal resistance to the hemibiotroph pathogen Pseudomonas syringae pv tomato (Pst). The Nt-Cys ETHYLENE RESPONSE FACTOR VII transcription factor substrates enhance pathogen-induced stomatal closure. Transgenic barley with reduced HvPRT6 expression showed enhanced resistance to Ps. japonica and Blumeria graminis f. sp. hordei, indicating a conserved role of the pathway. We propose that that separate branches of the N-end rule pathway act as distinct components of the plant immune response in flowering plants.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Doenças das Plantas/imunologia , Imunidade Vegetal , Pseudomonas syringae/fisiologia , Ubiquitina-Proteína Ligases/metabolismo , Arabidopsis/imunologia , Arabidopsis/microbiologia , Proteínas de Arabidopsis/genética , Ascomicetos/fisiologia , Etilenos/metabolismo , Hordeum/genética , Hordeum/imunologia , Hordeum/microbiologia , Oxirredução , Doenças das Plantas/microbiologia , Reguladores de Crescimento de Plantas/metabolismo , Estômatos de Plantas/genética , Estômatos de Plantas/imunologia , Estômatos de Plantas/microbiologia , Proteólise , Ubiquitina-Proteína Ligases/genética
9.
Endoscopy ; 51(7): 637-645, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31174224

RESUMO

BACKGROUND AND STUDY AIMS: Serrated polyposis syndrome (SPS) is a condition with high risk for colorectal cancer. The Endocuff device has been shown to increase adenoma detection in the general and screening population. We aimed to ascertain whether Endocuff-assisted colonoscopy increases detection of serrated lesions in comparison with standard colonoscopy during the surveillance of patients with SPS.  METHODS: In a multicenter randomized controlled study, patients who met SPS criteria I and/or III under surveillance (previous resection of all serrated lesions ≥ 4 mm) were consecutively randomly allocated 1:1 to Endocuff-assisted colonoscopy or standard colonoscopy, performed by expert endoscopists. The main outcome was the mean number of serrated lesions detected per patient. RESULTS: 122 patients (standard colonoscopy n = 60; Endocuff-assisted colonoscopy n = 62; 59 % men; mean age 60.6 (standard deviation [SD] 7.5) were included at 4 centers. Baseline variables (demographic data, SPS phenotype, colorectal cancer [CRC] history, cumulative polyps, and follow-up), cecal intubation rate, and withdrawal time were similar between groups. There was no statistically significant difference between Endocuff-assisted colonoscopy and standard colonoscopy for the mean number of serrated lesions detected per patient: 5.8 (95 % confidence interval [95 %CI] 4.4 - 7.2) and 5.0 (3.9 - 6.1), respectively (P = 0.36). There were also no differences between Endocuff-assisted and standard colonoscopy for detection of sessile serrated lesions (mean number per patient 2.5 [1.3 - 3.6] vs. 2.0 [1.1 - 3.0], P = 0.54) and adenomas (0.9 [0.5 - 1.3] vs. 0.5 [0.3 - 0.7], P = 0.12). CONCLUSION: Use of Endocuff-assisted colonoscopy did not significantly increase the number of serrated lesion detected per patient during surveillance of SPS.


Assuntos
Polipose Adenomatosa do Colo/diagnóstico , Neoplasias do Colo/diagnóstico , Colonoscopia/instrumentação , Detecção Precoce de Câncer , Desenho de Equipamento , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes
10.
Endoscopy ; 51(2): 142-151, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30068004

RESUMO

BACKGROUND: Serrated polyposis syndrome (SPS) has been associated with an increased risk of colorectal cancer (CRC). Accordingly, intensive surveillance with annual colonoscopy is advised. The aim of this multicenter study was to describe the risk of advanced lesions in SPS patients undergoing surveillance, and to identify risk factors that could guide the prevention strategy. METHODS: From March 2013 to April 2015, 296 patients who fulfilled criteria I and/or III for SPS were retrospectively recruited at 18 centers. We selected patients in whom successful clearing colonoscopy had been performed and who underwent subsequent endoscopic surveillance. Advanced neoplasia was defined as CRC, advanced adenoma, or advanced serrated lesion that were ≥ 10 mm and/or with dysplasia. Cumulative incidence of advanced neoplasia was calculated and independent predictors of advanced neoplasia development were identified. RESULTS: In 152 SPS patients a total of 315 surveillance colonoscopies were performed (median 2, range 1 - 7). The 3-year cumulative incidence of CRC and advanced neoplasia were 3.1 % (95 % confidence interval [CI] 0 - 6.9) and 42.0 % (95 %CI 32.4 - 51.7), respectively. Fulfilling both I + III criteria and the presence of advanced serrated lesions at baseline colonoscopy were independent predictors of advanced neoplasia development (odds ratio [OR] 1.85, 95 %CI 1.03 - 3.33, P  = 0.04 and OR 2.62, 95 %CI 1.18 - 5.81, P  = 0.02, respectively). During follow-up, nine patients (5.9 %) were referred for surgery for invasive CRC (n = 4, 2.6 %) or because of polyp burden (n = 5, 3.3 %). After total colectomy, 17.9 % patients developed advanced neoplasia in the retained rectum. CONCLUSIONS: Patients with SPS have a substantial risk of developing advanced neoplasia under endoscopic surveillance, whereas CRC incidence is low. Personalized endoscopic surveillance based on polyp burden and advanced serrated histology could help to optimize prevention in patients with SPS.


Assuntos
Polipose Adenomatosa do Colo/epidemiologia , Polipose Adenomatosa do Colo/patologia , Colonoscopia , Neoplasias Colorretais/epidemiologia , Neoplasias Colorretais/patologia , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Risco , Espanha/epidemiologia , Síndrome
11.
J Exp Bot ; 69(19): 4583-4590, 2018 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-29846689

RESUMO

Post-translational modifications are essential mediators between stimuli from development or the environment and adaptive transcriptional patterns. Recent data allow a first glimpse at how two modifications, phosphorylation and sumoylation, act interdependently to modulate stress responses. In particular, many components of the SUMO conjugation system are phosphoproteins, and some regulators and enzymes of protein phosphorylation can be sumoylated. Equally important, however, a number of proteins can be subject to both modifications. These substrates also have the capacity to connect stimuli transmitted via sumoylation with those transmitted via phosphorylation. As a prime example, we review data suggesting that nitrate reductase is a hub that integrates cues from these two modifications. Powerful proteomics approaches allowed the identification of additional common substrates, paving the way for studies to understand, on a broader basis, the cross-talk of phosphorylation with sumoylation and how it contributes to plant growth.


Assuntos
Fosforilação , Proteínas de Plantas/metabolismo , Proteínas Modificadoras Pequenas Relacionadas à Ubiquitina/metabolismo , Sumoilação/fisiologia , Proteoma
12.
Gut ; 65(11): 1829-1837, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-26264224

RESUMO

OBJECTIVE: Serrated polyposis syndrome (SPS) is associated with an increased colorectal cancer (CRC) risk, although the magnitude of the risk remains uncertain. Whereas intensive endoscopic surveillance for CRC prevention is advised, predictors that identify patients who have high CRC risk remain unknown. We performed a multicentre nationwide study aimed at describing the CRC risk in patients with SPS and identifying clinicopathological predictors independently associated with CRC. DESIGN: From March 2013 through September 2014, patients with SPS were retrospectively recruited at 18 Spanish centres. Data were collected from medical, endoscopy and histopathology reports. Multivariate logistic regression was performed to identify CRC risk factors. RESULTS: In 296 patients with SPS with a median follow-up time of 45 months (IQR 26-79.7), a median of 26 (IQR 18.2-40.7) serrated polyps and 3 (IQR 1-6) adenomas per patient were detected. Forty-seven patients (15.8%) developed CRC at a mean age of 53.9±12.8, and 4 out of 47 (8.5%) tumours were detected during surveillance (cumulative CRC incidence 1.9%). Patients with >2 sessile serrated adenomas/polyps (SSA/Ps) proximal to splenic flexure and ≥1 proximal SSA/P with high-grade dysplasia were independent CRC risk factors (incremental OR=2, 95% CI 1.22 to 3.24, p=0.006). Patients with no risk factors showed a 55% decrease in CRC risk (OR=0.45, 95% CI 0.24 to 0.86, p=0.01). CONCLUSIONS: Patients with SPS have an increased risk of CRC, although lower than previously published. Close colonoscopy surveillance in experienced centres show a low risk of developing CRC (1.9% in 5 years). Specific polyp features (SSA/P histology, proximal location and presence of high-grade dysplasia) should be used to guide clinical management.


Assuntos
Polipose Adenomatosa do Colo , Neoplasias Colorretais , Polipose Adenomatosa do Colo/diagnóstico , Polipose Adenomatosa do Colo/epidemiologia , Polipose Adenomatosa do Colo/patologia , Adulto , Idoso , Biópsia , Estudos de Coortes , Colonoscopia/métodos , Neoplasias Colorretais/diagnóstico , Neoplasias Colorretais/epidemiologia , Neoplasias Colorretais/patologia , Demografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , Fatores Socioeconômicos , Espanha/epidemiologia , Avaliação de Sintomas/métodos
13.
BMC Plant Biol ; 16(1): 251, 2016 11 11.
Artigo em Inglês | MEDLINE | ID: mdl-27835985

RESUMO

BACKGROUND: The induction of alcohol fermentation in roots is a plant adaptive response to flooding stress and oxygen deprivation. Available transcriptomic data suggest that fermentation-related genes are also frequently induced in roots infected with gall forming pathogens, but the biological significance of this induction is unclear. In this study, we addressed the role of hypoxia responses in Arabidopsis roots during infection by the clubroot agent Plasmodiophora brassicae. RESULTS: The hypoxia-related gene markers PYRUVATE DECARBOXYLASE 1 (PDC1), PYRUVATE DECARBOXYLASE 2 (PDC2) and ALCOHOL DEHYDROGENASE 1 (ADH1) were induced during secondary infection by two isolates of P. brassicae, eH and e2. PDC2 was highly induced as soon as 7 days post inoculation (dpi), i.e., before the development of gall symptoms, and GUS staining revealed that ADH1 induction was localised in infected cortical cells of root galls at 21 dpi. Clubroot symptoms were significantly milder in the pdc1 and pdc2 mutants compared with Col-0, but a null T-DNA insertional mutation of ADH1 did not affect clubroot susceptibility. The Arg/N-end rule pathway of ubiquitin-mediated proteolysis controls oxygen sensing in plants. Mutants of components of this pathway, ate1 ate2 and prt6, that both exhibit constitutive hypoxia responses, showed enhanced clubroot symptoms. In contrast, gall development was reduced in quintuple and sextuple mutants where the activity of all oxygen-sensing Group VII Ethylene Response Factor transcription factors (ERFVIIs) is absent (erfVII and prt6 erfVII). CONCLUSIONS: Our data demonstrate that the induction of PDC1 and PDC2 during the secondary infection of roots by P. brassicae contributes positively to clubroot development, and that this is controlled by oxygen-sensing through ERFVIIs. The absence of any major role of ADH1 in symptom development may also suggest that PDC activity could contribute to the formation of galls through the activation of a PDH bypass.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Arabidopsis/parasitologia , Plasmodioforídeos/fisiologia , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Regulação da Expressão Gênica de Plantas , Doenças das Plantas/parasitologia , Raízes de Plantas/genética , Raízes de Plantas/metabolismo , Raízes de Plantas/parasitologia
14.
Plant Physiol ; 166(2): 1022-32, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25118255

RESUMO

DELLA proteins are the master negative regulators in gibberellin (GA) signaling acting in the nucleus as transcriptional regulators. The current view of DELLA action indicates that their activity relies on the physical interaction with transcription factors (TFs). Therefore, the identification of TFs through which DELLAs regulate GA responses is key to understanding these responses from a mechanistic point of view. Here, we have determined the TF interactome of the Arabidopsis (Arabidopsis thaliana) DELLA protein GIBBERELLIN INSENSITIVE and screened a collection of conditional TF overexpressors in search of those that alter GA sensitivity. As a result, we have found RELATED TO APETALA2.3, an ethylene-induced TF belonging to the group VII ETHYLENE RESPONSE FACTOR of the APETALA2/ethylene responsive element binding protein superfamily, as a DELLA interactor with physiological relevance in the context of apical hook development. The combination of transactivation assays and chromatin immunoprecipitation indicates that the interaction with GIBBERELLIN INSENSITIVE impairs the activity of RELATED TO APETALA2.3 on the target promoters. This mechanism represents a unique node in the cross regulation between the GA and ethylene signaling pathways controlling differential growth during apical hook development.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Giberelinas/metabolismo , Fatores de Transcrição/metabolismo , Sequência de Bases , Primers do DNA , Reação em Cadeia da Polimerase , Regiões Promotoras Genéticas , Ligação Proteica , Ativação Transcricional
15.
J Strength Cond Res ; 29(12): 3494-505, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26595136

RESUMO

Variants of the solute carrier SLC16A1 gene have been associated with alterations in MCT1 expression, because of a lactate (La) transport deficiency across the cell membrane and a blood La accumulation. The aim of this study was to associate the allelic and genotypic frequencies of 1470T>A, 2917(1414) C>T, and IVS3-17A>C variants relative to the blood La kinetics and metabolic responses to a progressive effort until exhaustion. Twenty-five well-trained road cyclists performed a long-graded laboratory test: 10 minutes at 2.0 W·kg, first step at 2.5 W·kg with increments of 0.5 W·kg every 10 minutes until exhaustion. Blood La, nonesterified fatty acids (NEFAS), and glucose levels were measured; fat and carbohydrate oxidation rates were estimated through stoichiometric equations. Three variants of SLC16A1 gene were determined for each subject, which were divided in two groups: wt (wild type)/mt (mutated type) and mt/mt genotype group versus wt/wt genotype group. Metabolic responses were compared between both groups with an unpaired Student's t-test; Friedman and Wilcoxon tests were performed for nonparametric data. The statistical significance was set at p ≤ 0.05. For 1470TA polymorphism, no significant blood La differences were found between groups. 2197(1414)C>T allele carriers and IVS3-17A>C carriers showed significantly higher blood La levels, lower blood NEFAS, and glucose levels at submaximal intensities. These findings open a new perspective to investigate SLC16A1 variants (1470TA and IVS3-17A>C) on La deficiency transport and its regulation/interaction with other metabolic pathways. Future studies would be needed to clarify whether 1470T>A, 2917(1414)C>T, and IVS3-17A>C allelic/genotypic distribution benefit performance in endurance athletes.


Assuntos
Glicemia/metabolismo , Ácidos Graxos não Esterificados/sangue , Ácido Láctico/sangue , Transportadores de Ácidos Monocarboxílicos/genética , Simportadores/genética , Adulto , Ciclismo , Estudos Transversais , Teste de Esforço , Frequência do Gene , Genótipo , Humanos , Masculino , Redes e Vias Metabólicas/genética , Mutação , Resistência Física/fisiologia , Polimorfismo Genético , Adulto Jovem
16.
Plant Physiol ; 161(2): 617-27, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23370715

RESUMO

9-Lipoxygenases (9-LOXs) initiate fatty acid oxygenation, resulting in the formation of oxylipins activating plant defense against hemibiotrophic pathogenic bacteria. Previous studies using nonresponding to oxylipins (noxy), a series of Arabidopsis (Arabidopsis thaliana) mutants insensitive to the 9-LOX product 9-hydroxy-10,12,15-octadecatrienoic acid (9-HOT), have demonstrated the importance of cell wall modifications as a component of 9-LOX-induced defense. Here, we show that a majority (71%) of 41 studied noxy mutants have an added insensitivity to isoxaben, an herbicide inhibiting cellulose synthesis and altering the cell wall. The specific mutants noxy2, noxy15, and noxy38, insensitive to both 9-HOT and isoxaben, displayed enhanced susceptibility to Pseudomonas syringae DC3000 as well as reduced activation of salicylic acid-responding genes. Map-based cloning identified the mutation in noxy2 as At5g11630 encoding an uncharacterized mitochondrial protein, designated NOXY2. Moreover, noxy15 and noxy38 were mapped at the DYNAMIN RELATED PROTEIN3A and FRIENDLY MITOCHONDRIA loci, respectively. Fluorescence microscopy and molecular analyses revealed that the three noxy mutants characterized exhibit mitochondrial dysfunction and that 9-HOT added to wild-type Arabidopsis causes mitochondrial aggregation and loss of mitochondrial membrane potential. The results suggest that the defensive responses and cell wall modifications caused by 9-HOT are under mitochondrial retrograde control and that mitochondria play a fundamental role in innate immunity signaling.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Lipoxigenase/metabolismo , Proteínas Mitocondriais/metabolismo , Oxilipinas/metabolismo , Sequência de Aminoácidos , Arabidopsis/genética , Arabidopsis/microbiologia , Proteínas de Arabidopsis/genética , Benzamidas/farmacologia , Parede Celular/metabolismo , Resistência à Doença/efeitos dos fármacos , Resistência à Doença/genética , Regulação da Expressão Gênica de Plantas , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Interações Hospedeiro-Patógeno , Ácidos Linolênicos/metabolismo , Ácidos Linolênicos/farmacologia , Lipoxigenase/genética , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Microscopia Confocal , Microscopia de Fluorescência , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/genética , Mitocôndrias/metabolismo , Proteínas Mitocondriais/genética , Dados de Sequência Molecular , Mutação , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Plantas Geneticamente Modificadas , Pseudomonas syringae/fisiologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Homologia de Sequência de Aminoácidos
17.
Mol Biol Rep ; 41(3): 1267-72, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24430292

RESUMO

This study was designed to investigate the potential differences between Spaniards and Ecuadorian Mestizo people regarding CYP2C8, CYP2C9, and CYP2C19 genetic polymorphisms. DNA from 282 Spaniard and 297 Ecuadorian subjects were analyzed by either a previously reported pyrosequencing method (CY2C8*3, CYP2C9*2, CYP2C9*3, CYP2C19*2 and CYP2C19*3) or a nested PCR technique (CYP2C19*17). Whereas CYP2C19*17 allele distribution was higher in Ecuadorians than in Spaniards (P < 0.001) and the frequency of CYP2C19*3 was similar in these two populations (P > 0.05), the other allelic variants were detected at significantly lower frequencies in Ecuadorians than in Spaniards (P < 0.05). According to the diplotype distributions, the prevalence of the presumed CYP2C9 and CYP2C8 extensive metabolizers was higher in Ecuadorians than in Spaniards (P < 0.05). Individuals genotyped CYP2C19*1/*17 and *17/*17 who were considered as ultrarapid metabolizers were overrepresented in Ecuadorians in relation to Spaniards (P < 0.001). By contrast, among Ecuadorians no poor metabolizers (PMs) of either CYP2C8 or CYP2C9 were found and only two individuals were CYP2C19 PMs. These data are compatible with a higher CYP2C8, CYP2C9, and CYP2C19 activity in Mestizo Ecuadorians as opposed to Spaniards, which could imply differences in dosage requirements for drugs metabolized by these cytochromes and should also be considered in allele-disease association studies.


Assuntos
Hidrocarboneto de Aril Hidroxilases/genética , Genética Populacional , Adulto , Alelos , Citocromo P-450 CYP2C19 , Citocromo P-450 CYP2C8 , Citocromo P-450 CYP2C9 , Equador , Feminino , Humanos , Inativação Metabólica/genética , Indígenas Sul-Americanos/genética , Masculino , Polimorfismo Genético , População Branca/genética
18.
Rev Esp Enferm Dig ; 106(1): 59-62, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24689719

RESUMO

Lymphogranuloma venereum (LGV) is a sexually transmitted infectious disease caused by serovars L1, L2 and L3 of Chlamydia trachomatis. The initial presentation is usually a painless ulcerated papule on the genitalia or distal proctitis. The progression of the infection can lead to major complications: rectal strictures, intestinal obstruction or perforation. We present five cases of LGV proctitis as the initial presentation of the disease. All patients were male, mean age 44.6 years, with positive serology to human immunodeficiency virus (HIV) and promiscuous men who have sex with men (MSM).The initial diagnosis was made by rectosigmoidoscopy indicated for pain and anal discharge. All cases were confirmed by polymerase chain reaction technique in rectal tissue. Endoscopic images obtained showed a great variety of rectal lesions, from mild erythema of the mucosa and ulcers to deep ulcers with elevated borders and purulent exudate. All cases were resolved after treatment with doxycycline for 3 weeks. It emphasizes the importance of suspecting this re-emerging disease in patients with risk factors (HIV and MSM), with the aim of early treatment and to avoid major complications.


Assuntos
Linfogranuloma Venéreo/complicações , Proctite/etiologia , Adulto , Humanos , Linfogranuloma Venéreo/epidemiologia , Masculino , Pessoa de Meia-Idade , Proctite/epidemiologia
19.
Clin Transl Oncol ; 26(4): 825-835, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37787973

RESUMO

Watch-and-wait has emerged as a new strategy for the management of rectal cancer when a complete clinical response is achieved after neoadjuvant therapy. In an attempt to standardize this new clinical approach, initiated by the Spanish Cooperative Group for the Treatment of Digestive Tumors (TTD), and with the participation of the Spanish Association of Coloproctology (AECP), the Spanish Society of Pathology (SEAP), the Spanish Society of Gastrointestinal Endoscopy (SEED), the Spanish Society of Radiation Oncology (SEOR), and the Spanish Society of Medical Radiology (SERAM), we present herein a consensus on a watch-and-wait approach for the management of rectal cancer. We have focused on patient selection, the treatment schemes evaluated, the optimal timing for evaluating the clinical complete response, the oncologic outcomes after the implementation of this strategy, and a protocol for surveillance of these patients.


Assuntos
Neoplasias Retais , Conduta Expectante , Humanos , Consenso , Recidiva Local de Neoplasia/tratamento farmacológico , Neoplasias Retais/patologia , Terapia Neoadjuvante/métodos , Quimiorradioterapia/métodos , Resposta Patológica Completa , Resultado do Tratamento
20.
Artigo em Inglês | MEDLINE | ID: mdl-39033774

RESUMO

BACKGROUND: Computer-aided detection (CADe) systems for colonoscopy have been shown to increase small polyp detection during colonoscopy in the general population. People with Lynch syndrome represent an ideal target population for CADe-assisted colonoscopy because adenomas, the primary cancer precursor lesions, are characterised by their small size and higher likelihood of showing advanced histology. We aimed to evaluate the performance of CADe-assisted colonoscopy in detecting adenomas in individuals with Lynch syndrome. METHODS: TIMELY was an international, multicentre, parallel, randomised controlled trial done in 11 academic centres and six community centres in Belgium, Germany, Italy, and Spain. We enrolled individuals aged 18 years or older with pathogenic or likely pathogenic MLH1, MSH2, MSH6, or EPCAM variants. Participants were consecutively randomly assigned (1:1) to either CADe (GI Genius) assisted white light endoscopy (WLE) or WLE alone. A centre-stratified randomisation sequence was generated through a computer-generated system with a separate randomisation list for each centre according to block-permuted randomisation (block size 26 patients per centre). Allocation was automatically provided by the online AEG-REDCap database. Participants were masked to the random assignment but endoscopists were not. The primary outcome was the mean number of adenomas per colonoscopy, calculated by dividing the total number of adenomas detected by the total number of colonoscopies and assessed in the intention-to-treat population. This trial is registered with ClinicalTrials.gov, NCT04909671. FINDINGS: Between Sept 13, 2021, and April 6, 2023, 456 participants were screened for eligibility, 430 of whom were randomly assigned to receive CADe-assisted colonoscopy (n=214) or WLE (n=216). 256 (60%) participants were female and 174 (40%) were male. In the intention-to-treat analysis, the mean number of adenomas per colonoscopy was 0·64 (SD 1·57) in the CADe group and 0·64 (1·17) in the WLE group (adjusted rate ratio 1·03 [95% CI 0·72-1·47); p=0·87). No adverse events were reported during the trial. INTERPRETATION: In this multicentre international trial, CADe did not improve the detection of adenomas in individuals with Lynch syndrome. High-quality procedures and thorough inspection and exposure of the colonic mucosa remain the cornerstone in surveillance of Lynch syndrome. FUNDING: Spanish Gastroenterology Association, Spanish Society of Digestive Endoscopy, European Society of Gastrointestinal Endoscopy, Societat Catalana de Digestologia, Instituto Carlos III, Beca de la Marato de TV3 2020. Co-funded by the European Union.

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