RESUMO
DNA glycosylases initiate the base excision repair (BER) pathway by catalyzing the removal of damaged or mismatched bases from DNA. The Arabidopsis DNA glycosylase methyl-CpG-binding domain protein 4 like (MBD4L) is a nuclear enzyme triggering BER in response to the genotoxic agents 5-fluorouracil and 5-bromouracil. To date, the involvement of MBD4L in plant physiological processes has not been analyzed. To address this, we studied the enzyme functions in seeds. We found that imbibition induced the MBD4L gene expression by generating two alternative transcripts, MBD4L.3 and MBD4L.4. Gene activation was stronger in aged than in non-aged seeds. Seeds from mbd4l-1 mutants displayed germination failures when maintained under control or ageing conditions, while 35S:MBD4L.3/mbd4l-1 and 35S:MBD4L.4/mbd4l-1 seeds reversed these phenotypes. Seed nuclear DNA repair, assessed by comet assays, was exacerbated in an MBD4L-dependent manner at 24 h post-imbibition. Under this condition, the BER genes ARP, APE1L, and LIG1 showed higher expression in 35S:MBD4L.3/mbd4l-1 and 35S:MBD4L.4/mbd4l-1 than in mbd4l-1 seeds, suggesting that these components could coordinate with MBD4L to repair damaged DNA bases in seeds. Interestingly, the ATM, ATR, BRCA1, RAD51, and WEE1 genes associated with the DNA damage response (DDR) pathway were activated in mbd4l-1, but not in 35S:MBD4L.3/mbd4l-1 or 35S:MBD4L.4/mbd4l-1 seeds. These results indicate that MBD4L is a key enzyme of a BER cascade that operates during seed imbibition, whose deficiency would cause genomic damage detected by DDR, generating a delay or reduction in germination.
Assuntos
Proteínas de Arabidopsis , Arabidopsis , DNA Glicosilases , Reparo do DNA , Germinação , Sementes , Sementes/genética , Sementes/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , DNA Glicosilases/metabolismo , DNA Glicosilases/genética , Regulação da Expressão Gênica de Plantas , Dano ao DNARESUMO
La hemorragia digestiva determinada por una fístula entre manga gástrica y seudoaneurisma de arteria esplénica o polo superior de bazo es infrecuente. Se presenta un caso clínico de una paciente de 52 años con antecedentes de cirugía de manga gástrica y fuga anastomótica. Ingresó por hemorragia digestiva alta grave. Se operó de emergencia y realizó punto hemostático sobre cara posterior de manga gástrica. Se reintervino por resangrado realizándose la gastrectomía y esplenopancreatectomía distal por solución de continuidad de arteria esplénica. Dada la inestabilidad hemodinámica se efectuó un esofagostoma y yeyunostomía, reconstruyéndose a los 8 meses con buena evolución.
Gastrointestinal bleeding caused by a fistula between the gastric sleeve and a pseudoaneurysm of the splenic artery or upper pole of the spleen is uncommon. A clinical case of a 52-year-old patient with a history of gastric sleeve surgery and anastomotic leak is presented. She was admitted for severe upper gastrointestinal bleeding. She underwent emergency surgery and performed a hemostatic stitch on the posterior face of the gastric sleeve. She underwent reoperation due to rebleeding, performing gastrectomy and distal splenopancreatectomy due to discontinuation of the splenic artery. Given the hemodynamic instability, an esophagostomy and jejunostomy were performed, reconstructing at 8 months with good evolution.
O sangramento gastrointestinal causado por uma fístula entre a manga gástrica e um pseudoaneurisma da artéria esplênica ou pólo superior do baço é incomum. Apresenta-se o caso clínico de um paciente de 52 anos com história de cirurgia de manga gástrica e fístula anastomótica. Ele foi internado por hemorragia digestiva alta grave. Uma operação de emergência foi realizada e um ponto hemostático foi realizado na face posterior da manga gástrica. Foi reoperado por ressangramento, realizando gastrectomia e esplenopancreatectomia distal por descontinuação da artéria esplênica. Dada a instabilidade hemodinâmica, foi realizada esofagostomia e jejunostomia, reconstruindo aos 8 meses com boa evolução.
Assuntos
Humanos , Feminino , Pessoa de Meia-Idade , Artéria Esplênica/patologia , Fístula Gástrica/complicações , Cirurgia Bariátrica/efeitos adversos , Gastrectomia , Hemorragia Gastrointestinal/cirurgia , Complicações Pós-Operatórias , Doença Catastrófica , Emergências , Hemorragia Gastrointestinal/etiologiaRESUMO
The association between some bacterial infections and colon cancer is well documented. The most described is Streptococcus bovis infection. Another bacteria related to intestinal neoplasms is Clostridium septicum. We present the case of a 62-year-old man who consulted for abdominal pain associated with diarrhea and fever. A computed tomography scan of the abdomen and pelvis was performed, which revealed thickening of the cecum walls with an apparent break in continuity at its free edge. An exploratory laparotomy was performed which confirmed the presence of peritonitis and cecal perforation. A right hemicolectomy and terminal ileostomy were performed. The histopathological study revealed the presence of signet ring cell type adenocarcinoma associated with ischemia. The blood cultures results demonstrated the presence of C. septicum. The patient died due to fulminant sepsis.
Assuntos
Infecções por Clostridium , Clostridium septicum , Neoplasias do Colo , Perfuração Intestinal , Sepse , Infecções por Clostridium/complicações , Neoplasias do Colo/complicações , Neoplasias do Colo/cirurgia , Humanos , Perfuração Intestinal/diagnóstico por imagem , Masculino , Pessoa de Meia-IdadeRESUMO
Resumen La asociación entre algunas infecciones bacterianas y cáncer de colon está bien documentada. La más descrita es la infección por Streptococcus bovis. Otra bacteria relacionada a neoplasias intestinales es Clostridium septicum. Presentamos el caso clínico de un varón de 62 años que consultó por dolor abdominal, diarrea y fiebre. Se realizó una tomografía computada de abdomen y pelvis que evidenció un engrosamiento de las paredes del ciego con una aparente solución de continuidad en su borde libre. En una laparotomía exploradora se confirmó la presencia de peritonitis y perforación cecal, siendo sometido a una hemicolectomía derecha e ileostomía terminal. El estudio histopatológico reveló la presencia de un adenocarcinoma de tipo células en anillo de sello asociado a isquemia. Los hemocultivos fueron positivos a C. septicum. El paciente falleció por una sepsis fulminante.
Abstract The association between some bacterial infections and colon cancer is well documented. The most described is Streptococcus bovis infection. Another bacteria related to intestinal neoplasms is Clostridium septicum. We present the case of a 62-year-old man who consulted for abdominal pain associated with diarrhea and fever. A computed tomography scan of the abdomen and pelvis was performed, which revealed thickening of the cecum walls with an apparent break in continuity at its free edge. An exploratory laparotomy was performed which confirmed the presence of peritonitis and cecal perforation. A right hemicolectomy and terminal ileostomy were performed. The histopathological study revealed the presence of signet ring cell type adenocarcinoma associated with ischemia. The blood cultures results demonstrated the presence of C. septicum. The patient died due to fulminant sepsis.
Assuntos
Humanos , Masculino , Pessoa de Meia-Idade , Infecções por Clostridium/complicações , Neoplasias do Colo/cirurgia , Neoplasias do Colo/complicações , Sepse , Clostridium septicum , Perfuração Intestinal/diagnóstico por imagemAssuntos
Proteínas de Arabidopsis , Arabidopsis , DNA Glicosilases , Processamento Alternativo/genética , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , DNA Glicosilases/genética , DNA Glicosilases/metabolismo , Reparo do DNA , Resposta ao Choque Térmico/genéticaRESUMO
BACKGROUND: Liver resection represents the curative treatment of choice for patients with colorectal liver metastases (CRLM). Laparoscopic hepatectomy in CRLM is considered a safe approach. However, the information on their oncological results in the different series is deficient. This study aimed to compare the surgical margin, overall survival (OS), and disease-free survival (DFS) in patients with oncological resections of CRLM according to the type of surgical approach performed. METHODS: Between April 2007 and June 2017, 263 patients with CRLM underwent hepatic resection. Inclusion criteria were initial resectability, tumor size ≤ 50 mm, 3 or less metastases, no bilobar involvement, and absence of extrahepatic disease. A propensity score was performed to adjust the indication bias. RESULTS: Eighty-two patients were included (56 open and 26 laparoscopic). Twenty-eight (50%) patients had synchronous presentation in the open approach and 6 (23%) in the laparoscopic approach (p = 0.021), with more frequent simultaneous open resections (p = 0.037). The resection margin was positive (R1) in 5 patients with an open approach and 2 with a laparoscopic approach (8.9% and 7.6% respectively; p = 0.852). Nine patients (16%) with conventional approach and 2 (7.7%) with laparoscopic approach had local complications (p = 0.3). There was one death in the open group and none in the laparoscopic. There were no significant differences in OS and DFS rate between both groups (1-3 years, OS: 92-77% and 96-75% respectively; 1-3 years, DFS: 63-20% and 73-36% respectively). CONCLUSIONS: There were no significant differences in terms of surgical margin, OS rate, and DFS rate between the laparoscopic and open approach in patients with CRLM.
Assuntos
Neoplasias do Colo , Neoplasias Colorretais , Laparoscopia , Neoplasias Hepáticas , Neoplasias Retais , Neoplasias do Colo/cirurgia , Neoplasias Colorretais/patologia , Intervalo Livre de Doença , Hepatectomia/métodos , Humanos , Laparoscopia/métodos , Margens de Excisão , Neoplasias Retais/cirurgia , Estudos Retrospectivos , Resultado do TratamentoRESUMO
Arabidopsis contains two proline dehydrogenase (ProDH) genes, ProDH1 and ProDH2, encoding for homologous and functional isoenzymes. Although ProDH1 has been studied extensively, especially under abiotic stress, ProDH2 has only started to be analysed in recent years. These genes display distinctive expression patterns and show weak transcriptional co-regulation, but are both activated in pathogen-infected tissues. We have demonstrated previously that Arabidopsis plants with silenced ProDH1/2 expression fail to trigger defences against the hemibiotrophic bacterial pathogen Pseudomonas syringae pv. tomato AvrRpm1 (Pst-AvrRpm1), and that ProDH1 and ProDH2 are differentially regulated by salicylic acid (SA). In the current work, we used prodh1 and prodh2 single-mutant plants to assess the particular contribution of each gene to resistance against Pst-AvrRpm1 and the necrotrophic fungal pathogen Botrytis cinerea. In addition, we studied the sensitivity of ProDH1 and ProDH2 to the jasmonic acid (JA) defence pathway. We found that ProDH1 and ProDH2 are both necessary to achieve maximum resistance against Pst-AvrRpm1 and B. cinerea. However, ProDH2 has a major effect on early restriction of B. cinerea growth. Interestingly, ProDH1 is up-regulated by SA and JA, whereas ProDH2 is only activated by JA, and both genes display transcriptional inter-regulation at basal and infection conditions. These studies provide the first evidence of the contribution of ProDH2 to disease resistance, and describe the differential regulation and non-redundant but complementary function of both enzyme isoforms in infected tissues, providing support for a fundamental role of ProDH in the control of biotrophic and necrotrophic pathogens.
Assuntos
Proteínas de Arabidopsis/genética , Arabidopsis/genética , Arabidopsis/microbiologia , Botrytis/patogenicidade , Genes de Plantas , Proteínas Mitocondriais/genética , Doenças das Plantas/microbiologia , Prolina Oxidase/genética , Pseudomonas syringae/patogenicidade , Arabidopsis/efeitos dos fármacos , Proteínas de Arabidopsis/metabolismo , Ciclopentanos/farmacologia , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Proteínas Mitocondriais/metabolismo , Mutação/genética , Oxilipinas/farmacologia , Doenças das Plantas/genética , Prolina Oxidase/metabolismo , Ácido Salicílico/farmacologiaRESUMO
L-proline (Pro) catabolism is activated in plants recovering from abiotic stresses associated with water deprivation. In this catabolic pathway, Pro is converted to glutamate by two reactions catalyzed by proline dehydrogenase (ProDH) and Δ(1)-pyrroline-5-carboxylate dehydrogenase (P5CDH), with Δ(1)-pyrroline-5-carboxylate (P5C) as the intermediate. Alternatively, under certain conditions, the P5C derived from Pro is converted back to Pro by P5C reductase, thus stimulating the Pro-P5C cycle, which may generate reactive oxygen species (ROS) as a consequence of the ProDH activity. We previously observed that Pro biosynthesis is altered in Arabidopsis (Arabidopsis thaliana) tissues that induce the hypersensitive response (HR) in response to Pseudomonas syringae. In this work, we characterized the Pro catabolic pathway and ProDH activity in this model. Induction of ProDH expression was found to be dependent on salicylic acid, and an increase in ProDH activity was detected in cells destined to die. To evaluate the role of ProDH in the HR, ProDH-silenced plants were generated. These plants displayed reduced ROS and cell death levels as well as enhanced susceptibility in response to avirulent pathogens. Interestingly, the early activation of ProDH was accompanied by an increase in P5C reductase but not in P5CDH transcripts, with few changes occurring in the Pro and P5C levels. Therefore, our results suggest that in wild-type plants, ProDH is a defense component contributing to HR and disease resistance, which apparently potentiates the accumulation of ROS. The participation of the Pro-P5C cycle in the latter response is discussed.
Assuntos
Arabidopsis/enzimologia , Imunidade Vegetal , Prolina Oxidase/metabolismo , Prolina/metabolismo , Ácido Salicílico/metabolismo , 1-Pirrolina-5-Carboxilato Desidrogenase/genética , 1-Pirrolina-5-Carboxilato Desidrogenase/metabolismo , Arabidopsis/genética , Arabidopsis/imunologia , Morte Celular , Regulação da Expressão Gênica de Plantas , Inativação Gênica , Plantas Geneticamente Modificadas/enzimologia , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/imunologia , Prolina Oxidase/genética , Pseudomonas syringae/patogenicidade , Espécies Reativas de Oxigênio/análiseRESUMO
Plant suspension cell cultures display many features of the innate immune responses observed in planta and have been extensively applied to the study of basal and race-specific defences. However, no single model including photosynthetic cultured cells has been used for the exhaustive characterization of both basal and race-specific defences to date. In this article, we report the activation of basal and race-specific defences in green cultured cells from Arabidopsis thaliana. Inoculation of cultured cells with isogenic virulent or avirulent strains of Pseudomonas syringae pv. tomato DC3000 (Pst) was used to evaluate race-specific defences. The proliferation of avirulent Pst was found to be lower than that of virulent Pst in the inoculated cultures. Extracellular pH changes, sustained oxidative burst (5-13 h post-inoculation), enhancement of salicylic acid, and massive cell death were specifically stimulated by the avirulent bacterium. Neither avirulent nor virulent Pst induced markers of basal resistance, such as callose deposition or early oxidative burst (1-5 h post-inoculation). However, both basal defences were activated when cells were exposed to Pseudomonas syringae pv. phaseolicola or to the Pst mutant defective in the type III secretion system (TTSS), Pst-hrpL(-). Thus, in these cells, basal defences may be inhibited by Pst in a TTSS-dependent manner. Recapitulation of classical defence features demonstrates the usefulness of this system for the fine characterization of plant innate immune components.