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1.
Sci Rep ; 13(1): 16470, 2023 09 30.
Artículo en Inglés | MEDLINE | ID: mdl-37777633

RESUMEN

DNA damage contributes to atherosclerosis. However, causative links between DNA double-strand breaks (DSBs) and atherosclerosis have yet to be established. Here, we investigated the role of DSBs in atherosclerosis using mice and vascular cells deficient in Ku80, a DSB repair protein. After 4 weeks of a high-fat diet, Ku80-deficient apolipoprotein E knockout mice (Ku80+/-ApoE-/-) displayed increased plaque size and DSBs in the aorta compared to those of ApoE-/- control. In the preatherosclerotic stages (two-week high-fat diet), the plaque size was similar in both the Ku80+/-ApoE-/- and ApoE-/- control mice, but the number of DSBs and mRNA levels of inflammatory cytokines such as IL-6 and MCP-1 were significantly increased in the Ku80+/-ApoE-/- aortas. We further investigated molecular links between DSBs and inflammatory responses using vascular smooth muscle cells isolated from Ku80 wild-type and Ku80+/- mice. The Ku80+/- cells displayed senescent features and elevated levels of inflammatory cytokine mRNAs. Moreover, the cytosolic DNA-sensing cGAS-STING pathway was activated in the Ku80+/- cells. Inhibiting the cGAS-STING pathway reduced IL-6 mRNA level. Notably, interferon regulatory factor 3 (IRF3), a downstream effector of the cGAS-STING pathway, was activated, and the depletion of IRF3 also reduced IL-6 mRNA levels in the Ku80+/- cells. Finally, DSBs accumulation in normal cells also activated the cGAS-STING-IRF3 pathway. In addition, cGAS inhibition attenuated DNA damage-induced IL-6 expression and cellular senescence in these cells. These results suggest that DSBs accumulation promoted atherosclerosis by upregulating proinflammatory responses and cellular senescence via the cGAS-STING (-IRF3) pathway.


Asunto(s)
Aterosclerosis , Roturas del ADN de Doble Cadena , Placa Aterosclerótica , Animales , Ratones , Apolipoproteínas E , Aterosclerosis/genética , Citocinas/metabolismo , ADN/metabolismo , Interleucina-6 , Ratones Noqueados , Nucleotidiltransferasas/metabolismo
2.
J Biochem ; 173(5): 375-382, 2023 Apr 26.
Artículo en Inglés | MEDLINE | ID: mdl-36634373

RESUMEN

Klotho is an anti-aging, single-pass transmembrane protein found mainly in the kidney. Although aging is likely to be associated with DNA damage, the involvement of Klotho in protecting cells from DNA damage is still unclear. In this study, we examined DNA damage in human kidney cells and mouse kidney tissue after ionizing radiation (IR). The depletion and overexpression of Klotho in human kidney cells reduced and increased the cell survival rates after IR, respectively. The formation of γ-H2AX foci, representing DNA damage, was significantly elevated immediately after IR in cells with Klotho depletion and decreased in cells overexpressing Klotho. These results were confirmed in mouse renal tissues after IR. Quantification of DNA damage by a comet assay revealed that the Klotho knockdown significantly increased the amount of DNA damage immediately after IR, suggesting that Klotho protects chromosomal DNA from the induction of damage, rather than facilitating DNA repair. Consistent with this notion, Klotho was detected in both the nucleus and cytoplasm. In the nucleus, Klotho may serve to protect chromosomal DNA from damage, leading to its anti-aging effects.


Asunto(s)
Envejecimiento , Reparación del ADN , Histonas , Proteínas Klotho , Animales , Humanos , Ratones , Envejecimiento/genética , ADN , Daño del ADN , Histonas/metabolismo , Proteínas Klotho/genética , Proteínas Klotho/metabolismo
3.
Radiat Res ; 197(4): 384-395, 2022 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-35090038

RESUMEN

Contrast media has been shown to induce nephropathy (i.e., contrast-induced nephropathy) after various types of radiological examinations. The molecular mechanism of contrast-induced nephropathy has been unclear. In this study, we investigated the mechanism of contrast-induced nephropathy by examining the effects of combined treatment of contrast medium and ionizing radiation on kidney cells in vitro and kidney tissue in vivo. In human renal tubular epithelium cells, immunofluorescence analysis revealed that iohexol increased the numbers of radiation-induced γH2AX nuclear foci. The numbers of γH2AX nuclear foci remained high at 24 h, suggesting that some radiation-induced double-strand breaks remain unrepaired in the presence of iohexol. We established a mouse model of contrast-induced nephropathy, then showed that iohexol and ionizing radiation synergistically reduced renal function and induced double-strand breaks. Importantly, iohexol induced significant macrophage accumulation and oxidative DNA damage in the kidneys of contrast-induced nephropathy model mice in the absence of ionizing radiation; these effects were amplified by ionizing radiation. The results suggest that underlying inflammation and oxidative DNA damage caused by iohexol contribute to the enhancement of radiation-induced double-strand breaks, leading to contrast-induced nephropathy.


Asunto(s)
Yohexol , Enfermedades Renales , Animales , Medios de Contraste/efectos adversos , Daño del ADN , Yohexol/efectos adversos , Riñón/fisiología , Enfermedades Renales/inducido químicamente , Ratones , Radiación Ionizante
4.
CEN Case Rep ; 8(4): 266-270, 2019 11.
Artículo en Inglés | MEDLINE | ID: mdl-31177384

RESUMEN

Thrombotic microangiopathies include hemolytic uremic syndrome (HUS) and thrombotic thrombocytopenic purpura (TTP). Measurement of plasma levels of "a disintegrin-like and metalloproteinase with thrombospondin type 1 motifs 13" (ADAMTS13) activity can distinguish HUS from TTP. Reduced plasma ADAMTS13 activity (< 10% normal range) is atypical for HUS, but not for TTP. However, we detected reduced ADAMTS13 activity in a patient with Shiga toxin-producing Escherichia coli-associated HUS caused by non-IgG anti-ADMTS13 autoantibodies. Furthermore, the patient exhibited possible genetic abnormalities associated with atypical HUS. The patient fully recovered after administration of supportive therapy. To the best of our knowledge, very few cases of STEC-HUS with reduced ADAMTS13 activity have been reported; thus far, none have described the presence of non-IgG anti-ADMTS13 autoantibodies. Therefore, we suggest that anti-ADAMTS13 analyses should be performed in patients diagnosed with STEC-HUS, especially in those who present with prolonged healing or unexpected clinical symptoms.


Asunto(s)
Proteína ADAMTS13/sangre , Desintegrinas/sangre , Síndrome Hemolítico-Urémico/microbiología , Escherichia coli Shiga-Toxigénica/aislamiento & purificación , Autoanticuerpos/sangre , Transfusión de Eritrocitos/métodos , Femenino , Síndrome Hemolítico-Urémico/genética , Síndrome Hemolítico-Urémico/terapia , Humanos , Infusiones Intravenosas/métodos , Proteína Cofactora de Membrana/genética , Púrpura Trombocitopénica Trombótica/diagnóstico , Insuficiencia Renal/diagnóstico , Insuficiencia Renal/etiología , Índice de Severidad de la Enfermedad , Microangiopatías Trombóticas/complicaciones , Microangiopatías Trombóticas/diagnóstico , Resultado del Tratamiento , Adulto Joven
5.
Dig Surg ; 32(5): 353-60, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26228297

RESUMEN

AIM: To evaluate the effect of Tri-staple technology and slow firing using the Endo-GIA endoscopic linear stapler. METHODS: The cardiac and pyloric portions of porcine stomachs were divided using the endoscopic linear stapler with different reload types. A total of 8 min of waiting time was employed during firing in the slow-firing group and no waiting time was employed in the normal-firing group. The shape of the staples was then evaluated. The length of the staple line and serosal laceration was also determined. RESULTS: There was a moderate negative correlation between tissue thickness and secure staple formation. Tri-staple reloads (purple, black) offered more secure staple formation compared with Universal green reload. Although slow firing enhanced secure staple formation, its effect was greater when using green reload, compared with Tri-staple reloads. Significantly shorter staple line length and longer serosal laceration was observed in the thick tissue. Although the cartridge type did not influence lengths of the staple line or serosal laceration, both were better in the slow-firing group. CONCLUSIONS: Tri-staple reloads offered more secure staple formation compared with the Universal reload. Although slow firing improved staple line shortening and serosal laceration, its effect on secure stapling was relatively small when using Tri-staple reloads.


Asunto(s)
Endoscopía Gastrointestinal/instrumentación , Estómago/cirugía , Engrapadoras Quirúrgicas , Grapado Quirúrgico/instrumentación , Anastomosis Quirúrgica , Animales , Grapado Quirúrgico/métodos , Porcinos
6.
J Surg Res ; 193(2): 652-7, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25277356

RESUMEN

BACKGROUND: Anastomotic leakage is a serious complication after rectal surgery. The aim of this study was to assess the effect of waiting time during firing of stapling devices on optimal staple formation. METHODS: An endoscopic linear stapler (Echelon Flex 60 Endopath) with either a 60 mm blue or gold cartridge was applied to the cardiac and pyloric portions of 27 fresh porcine stomachs. Three different waiting times were used for the precompression and interstroke periods (0/0, 2/0, and 2/2 min). The staple line was divided into four portions (oral, anal and top, base), and the shape of each staple was evaluated. Optimal staple formation was also assessed using the circular stapler (CDH 29). RESULTS: Mean thickness of the cardiac and pyloric portions was 2.4 ± 0.35 mm and 4.0 ± 0.4 mm, respectively. The waiting time improved optimal staple formation for the blue cartridge, especially when it was used for the pyloric portion. Staple malformation was observed more commonly in the top portion than in the base portion; however, the former was improved by an interstroke waiting time. Staple formation using the circular stapler was satisfactory and not influenced by the prefiring waiting time or tissue thickness. CONCLUSIONS: Employment of a waiting time improves optimal staple formation when the endoscopic linear stapler is used for challenging tissue.


Asunto(s)
Anastomosis Quirúrgica/métodos , Engrapadoras Quirúrgicas , Suturas , Animales , Porcinos , Porcinos Enanos , Factores de Tiempo
7.
Gan To Kagaku Ryoho ; 41(2): 257-9, 2014 Feb.
Artículo en Japonés | MEDLINE | ID: mdl-24743210

RESUMEN

Here we report gastric cancer accompanied by bone marrow carcinomatosis in a patient for whom long-term chemotherapy was enabled by early pain-relief therapy. A 45-year-old man was admitted to our hospital because of back pain associated with multiple spinal tumors in June 2011. Blood tests showed a trend toward disseminated intravascular coagulation(DIC) and gastric cancer was suspected as the primary lesion. Because pain was severe, emergency pain relief was provided by flurbiprofen axetil and a continuous subcutaneous infusion of fentanyl citrate. After bone marrow examination gave a diagnosis of poorly differentiated adenocarcinoma, we performed sequential methotrexate(MTX)and 5-fluorouracil(5-FU)therapy. The therapy successfully decreased tumor marker levels, and alkaline phosphatase and lactate dehydrogenase levels normalized. Finally, gastric cancer accompanied by bone marrow carcinomatosis was diagnosed. Because the patient had anxiety and spiritual pain from the time of admission, psychiatric care was also required. In November 2011, the tumor recurred, and we switched therapy to a combination of S-1 and cisplatin. The patient's pain was controlled by combined treatment with a fentanyl patch and etodolac, and he was discharged in December 2011. However, severe pain recurred and pain therapy was continued. DIC developed in February 2012 and transiently resolved after resuming combination therapy with MTX and 5-FU; however, it subsequently recurred, leading to the patient's death in May 2012.


Asunto(s)
Adenocarcinoma/terapia , Neoplasias de la Médula Ósea/terapia , Cuidados Paliativos , Neoplasias Gástricas/terapia , Adenocarcinoma/secundario , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Neoplasias de la Médula Ósea/secundario , Resultado Fatal , Humanos , Masculino , Persona de Mediana Edad , Neoplasias Gástricas/patología , Factores de Tiempo
8.
Gan To Kagaku Ryoho ; 41 Suppl 1: 20-2, 2014 Dec.
Artículo en Japonés | MEDLINE | ID: mdl-25595072

RESUMEN

The intervention of palliative care from the early stages of cancer is advocated, however, current situation remains virtually unchanged. Since the Baptist Home Hospice Palliative Care Clinic opened, the percentage of patients who have been introduced to the clinic during chemotherapy and have received home-visit care is 16.1%. Of those, the percentage of patients who passed away more than two months since the start of home-visit care is 45.7%. We determine the direction in care by listening closely to our patients and their families, and putting advance care planning (ACP) into effect. One of our roles is to offer support in deciding to discontinue the treatment in the final stages of chemotherapy. It is recognized that a number of patients are undergoing ineffective chemotherapy, despite the strong side effects. Our clinic strives to help these patients spend time the way they want by providing home-visit care and home-visit nursing.


Asunto(s)
Toma de Decisiones , Servicios de Atención de Salud a Domicilio , Neoplasias , Adulto , Planificación Anticipada de Atención , Anciano , Anciano de 80 o más Años , Cuidadores , Femenino , Humanos , Masculino , Persona de Mediana Edad , Neoplasias/tratamiento farmacológico , Pacientes Ambulatorios , Adulto Joven
9.
Gan To Kagaku Ryoho ; 41 Suppl 1: 60-2, 2014 Dec.
Artículo en Japonés | MEDLINE | ID: mdl-25595085

RESUMEN

The Japan Baptist Medical Foundation has established a "hospice triangle" system consisting of the hospice ward, general ward, and home hospice. Palliative care is provided for patients with various types of cancer, including hematological malignancies, in the place where they desire to receive care. From December 2010 to December 2013, 37 patients with hematological malignancies received palliative care and died at our foundation. Eleven (30%) patients died in the hospice ward, 24 (65%) in the general ward, and 2 (5%) at home. The median interval between the final dose of chemotherapy and death was 12 (1- 88) days. Twenty (54%) patients received transfusions during the last 2 weeks prior to death. Quick response to patient situations and early introduction of palliative care are essential to support end-of-life decision-making processes, because the clinical course of hematological malignancies generally differs from that of other cancers.


Asunto(s)
Neoplasias Hematológicas/terapia , Cuidados Paliativos , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Japón , Masculino , Persona de Mediana Edad
10.
Psychiatr Genet ; 23(6): 255-7, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23982282

RESUMEN

Previous studies have reported that the hypothalamic-pituitary-adrenal axis is involved with personality traits. We examined the association between corticotropin-releasing hormone receptor (CRHR) genes and personality traits. We investigated the 12 single-nucleotide polymorphisms of intron CRHR (six in CRHR1 and six in CRHR2, respectively) in 218 healthy volunteers using TaqMan PCR assays. Personality traits were assessed using the Revised NEO-Personality Inventory, the Temperament and Character Inventory, and the State-Trait Anxiety Inventory. No significant associations were observed between CRHR1 and CRHR2 expression and personality traits. These results fail to provide support for an association of CRHR1 and CRHR2 with personality traits in a Japanese adult population.


Asunto(s)
Estudios de Asociación Genética , Predisposición Genética a la Enfermedad , Personalidad/genética , Polimorfismo de Nucleótido Simple/genética , Receptores de Hormona Liberadora de Corticotropina/genética , Adulto , Pueblo Asiatico/genética , Humanos
11.
Gan To Kagaku Ryoho ; 40 Suppl 2: 191-4, 2013 Dec.
Artículo en Japonés | MEDLINE | ID: mdl-24712142

RESUMEN

The Japan Baptist Medical Foundation forms a so-called hospice triangle, with a general ward, a hospice ward, and home hospice, and it is possible to provide palliative care in the desired place. The ratio of homecare is 65.0%, and there were 2 cases in which a physician was present at the time of death. The average number of home-visit medical treatments during the week prior to death was 3.7. The median value of the period of home-visit medical treatment is 36 days. The group of homecare patients who were temporarily hospitalized during the period of home-visit medical treatment was 17.1%, and the most common reason was exacerbation of symptoms related to the primary disease. The group of patients who were hospitalized in a hospice ward was 17.0%, and many were for the purpose of respite care or trial hospitalization. Because some patients are reluctant to be hospitalized in a hospice ward, it was thought that adding an option of hospitalizing in a cooperating hospital to the homecare support system would give patients peace of mind. In order to increase the use of homecare from now on, it was thought that even further education about homecare is necessary in addition to a support system of cooperating hospitals.


Asunto(s)
Servicios de Atención de Salud a Domicilio , Hospitalización , Grupo de Atención al Paciente , Cuidado Terminal , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Hospitales para Enfermos Terminales , Humanos , Masculino , Persona de Mediana Edad , Cuidados Paliativos
12.
Gan To Kagaku Ryoho ; 39 Suppl 1: 30-2, 2012 Dec.
Artículo en Japonés | MEDLINE | ID: mdl-23268892

RESUMEN

Home hospice care is not merely an extension of hospital-based medical care administered at the hospital, but refers to hospice care for patients with life-threatening diseases that can only be given at their homes. The rapid growth of the elderly population in Japan has led to not only the need for home hospice care, but also social problems such as living alone, living with only one elderly family member, and problems that are particularly acute in cancer patients with dementia. We analyzed data for 262 patients for whom home hospice care was provided by our clinic. Overall, elderly persons with dementia tended to request admission before death, but most elderly persons living alone preferred home hospice care. We found that 58% of the patients living with only one elderly family member requested admission before death, which was lower than the rate of the study group as a whole. We further performed an in-depth analysis of the current situation in order to improve home hospice care of terminally ill patients in Japan, focusing on problems related to the aging population.


Asunto(s)
Servicios de Atención de Salud a Domicilio , Cuidados Paliativos al Final de la Vida , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad
13.
Gan To Kagaku Ryoho ; 39 Suppl 1: 64-6, 2012 Dec.
Artículo en Japonés | MEDLINE | ID: mdl-23268903

RESUMEN

In November 2009, a home hospice palliative care clinic(clinic)was opened in addition to a hospice ward, general ward, and geriatric health services facility at our hospital. This marked the initiation of a health care system able to provide the palliative care desired by patients and families. We studied the characteristics and hospitalization status of 514 patients with cancer who died at the hospice ward, general ward, or their homes from November 2009 through December 2011. Overall, 373 patients died at the hospice ward, 11 at the general ward, and 130 at home. Hospice physicians participated in the home care of 20 patients. Hospice physicians provide home-based care in cooperation with clinic physicians, facilitating the palliative care of patients who initially do not have a place to receive terminal care and the prompt discharge of patients who want to live at home.


Asunto(s)
Servicios de Atención de Salud a Domicilio , Cuidados Paliativos al Final de la Vida , Cuidados Paliativos , Adulto , Anciano , Anciano de 80 o más Años , Redes Comunitarias , Femenino , Servicios de Salud para Ancianos , Hospitales , Humanos , Masculino , Persona de Mediana Edad , Neoplasias/terapia , Grupo de Atención al Paciente , Adulto Joven
14.
Am J Med Genet B Neuropsychiatr Genet ; 159B(4): 429-36, 2012 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-22467522

RESUMEN

Major depressive disorder (MDD) and panic disorder (PD) are common and disabling medical disorders with stress and genetic components. Dysregulation of the stress response of the hypothalamic-pituitary-adrenal axis, including the corticotrophin-releasing hormone (CRH) signaling via primary receptors (CRHR1 and CRHR2), is considered to play a major role for onset and recurrence in MDD and PD. To confirm the association of CRHR1 and CRHR2 with MDD and PD, we investigated 12 single nucleotide polymorphisms (SNPs) (rs4076452, rs7209436, rs110402, rs242924, rs242940, and rs173365 for CRHR1 and rs4722999, rs3779250, rs2267710, rs1076292, rs2284217, and rs226771 for CRHR2) in MDD patients (n = 173), PD patients (n = 180), and healthy controls (n = 285). The SNP rs110402 and rs242924 in the CRHR1 gene and the rs3779250 in the CRHR2 gene were associated with MDD. The SNP rs242924 in the CRHR1 gene was also associated with PD. The T-A-T-G-G haplotype consisting of rs7209436 and rs173365 in CRHR1 was positively associated with MDD. The T-A haplotype consisting of rs7209436 and rs110402 in CRHR1 was positively associated with MDD. The C-C haplotype consisting of rs4722999 and rs37790 in CRHR1 was associated with PD. These results provide support for an association of CRHR1 and CRHR2 with MDD and PD.


Asunto(s)
Pueblo Asiatico/genética , Trastorno Depresivo Mayor/genética , Estudios de Asociación Genética , Predisposición Genética a la Enfermedad , Trastorno de Pánico/genética , Receptores de Hormona Liberadora de Corticotropina/genética , Adulto , Estudios de Casos y Controles , Femenino , Frecuencia de los Genes/genética , Genética de Población , Haplotipos/genética , Humanos , Masculino , Polimorfismo de Nucleótido Simple/genética
15.
Surg Endosc ; 25(7): 2382-6, 2011 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-21184102

RESUMEN

BACKGROUND: One prerequisite for the safe stapling of anastomoses is the formation of perfectly aligned B-shaped staples. Using an animal model, this study investigated whether precompression enhances secure staple formation. METHODS: A 45-mm linear stapler with a blue cartridge (staple leg length, 3.5 mm) was used on three portions each of six porcine stomachs (cardia, center, and pylorus). Staple shape and height were examined according to the precompression time (0, 1, or 5 min) before firing. The shape was classified as optimal or suboptimal, and the heights of the staples were measured individually. The completeness of the proximal staple lines also was compared with the distal lines. RESULTS: The optimal staple rate in the 5-min group (52.7%) was significantly higher than in the 1-min group (28.7%; p<0.001) or the 0-min group (17.1%; p=0.002). The optimal staple rate in the 5-min group for the cardiac portion (mean wall thickness, 2.7 mm) reached 98.9%. However, this rate was less than 50% in the center (5.3 mm) and pylorus (4.2 mm) portions regardless of the precompression time. Compared with the root side, the top side of the cartridge had a lower optimal rate (45.3 vs. 18.7%; p<0.001). A high correlation of completeness was observed between the distal and proximal sides of the stump. CONCLUSIONS: When a linear stapling device is used, proper staple formation is correlated with intestinal wall thickness, and a sufficient amount of precompression time is effective for gaining the secure staple formation.


Asunto(s)
Estómago/cirugía , Grapado Quirúrgico/métodos , Anastomosis Quirúrgica/métodos , Animales , Distribución de Chi-Cuadrado , Diseño de Equipo , Modelos Animales , Presión , Engrapadoras Quirúrgicas , Porcinos , Porcinos Enanos , Factores de Tiempo
16.
Intern Med ; 49(8): 781-5, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-20424371

RESUMEN

We report the case of a woman with intracranial metastasis from an esophageal gastrointestinal stromal tumor (GIST) with the mutation site in the 3' end of exon 11. Frontal craniotomy was performed with complete resection of the mass, followed by postoperative stereotaxic radiotherapy (SRT). Intracranial metastasis from GISTs is extremely rare; we found only seven case reports in the literature.


Asunto(s)
Neoplasias Encefálicas/diagnóstico , Neoplasias Encefálicas/secundario , Neoplasias Esofágicas/diagnóstico , Tumores del Estroma Gastrointestinal/diagnóstico , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/terapia , Neoplasias Esofágicas/genética , Neoplasias Esofágicas/terapia , Femenino , Tumores del Estroma Gastrointestinal/genética , Tumores del Estroma Gastrointestinal/terapia , Humanos , Persona de Mediana Edad , Mutación/genética
17.
FEMS Microbiol Lett ; 293(1): 79-84, 2009 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-19236484

RESUMEN

An actinomycete strain, Amycolatopsis sp. CsO-2, produces a 27-kDa chitosanase. To reveal the molecular characteristics of the enzyme, its corresponding gene ctoA was cloned by a reverse genetic technique, based on the N-terminal amino acid sequence of the protein. The encoded CtoA protein was deduced to be composed of 286 amino acids, including a putative signal peptide (1-48), and exhibited 83% identity in the amino acid sequence with the family 46 chitosanases from Streptomyces sp. N174 or Nocardioides sp. N106. The active recombinant CtoA protein was successfully overproduced in Escherichia coli. The mutant protein E22Q, in which the glutamic acid residue 22 was replaced with glutamine, abolished the chitosanase activity, showing that the Glu22 residue is required for the enzymatic activity. CtoA exhibited antifungal activity against Rhizopus oryzae, which is known to produce chitosan probably as a cell wall component. In contrast, E22Q did not inhibit the growth of the fungus, suggesting that chitosan-hydrolyzing activity is essential for the antifungal activity. It is noteworthy that the antifungal effect of CtoA against R. oryzae was drastically enhanced by the simultaneous addition of the family 19 chitinase ChiC from Streptomyces griseus.


Asunto(s)
Actinomycetales/enzimología , Antifúngicos , Proteínas Fúngicas , Glicósido Hidrolasas , Rhizopus/efectos de los fármacos , Actinomycetales/genética , Antifúngicos/farmacología , Quitinasas/genética , Quitinasas/metabolismo , Quitosano/metabolismo , Clonación Molecular , Escherichia coli/enzimología , Escherichia coli/genética , Proteínas Fúngicas/química , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Glicósido Hidrolasas/biosíntesis , Glicósido Hidrolasas/química , Glicósido Hidrolasas/genética , Mutagénesis Sitio-Dirigida , Mutación , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Análisis de Secuencia de ADN
19.
Planta ; 216(6): 961-8, 2003 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-12687363

RESUMEN

The spinach ( Spinacia oleracea L. (cv. Hoyo) nitrate reductase inactivator (NRI) is a novel protein that irreversibly inactivates NR. Using degenerate primers based on an N-terminal amino acid sequence of NRI purified from spinach leaves and a cDNA library, we isolated a full-length NRI cDNA from spinach that contains an open reading frame encoding 479 amino acid residues. This protein shares 67.4% and 51.1-68.3% amino acid sequence similarities with a nucleotide pyrophosphatase (EC 3.6.1.9) from rice and three types of the nucleotide pyrophosphatase-like protein from Arabidopsis thaliana, respectively. Immunoblot analysis revealed that NRI was constitutively expressed in suspension-cultured spinach cells; however, its expression level is quite low in 1-day-subcultured cells. Moreover, northern blot analysis indicated that this expression was regulated at the mRNA level. These results suggest that NRI functions in mature cells.


Asunto(s)
ADN Complementario/genética , Genes de Plantas/genética , Nitrato Reductasas/antagonistas & inhibidores , Proteínas de Plantas/biosíntesis , Proteínas de Plantas/genética , Spinacia oleracea/genética , Secuencia de Aminoácidos , Secuencia de Bases , Células Cultivadas , Clonación Molecular , Reacciones Cruzadas/inmunología , Regulación de la Expresión Génica de las Plantas , Datos de Secuencia Molecular , Nitrato-Reductasa , Proteínas de Plantas/química , Proteínas de Plantas/inmunología , Reacción en Cadena de la Polimerasa , ARN Mensajero/genética , ARN Mensajero/metabolismo , Análisis de Secuencia de Proteína , Homología de Secuencia de Aminoácido , Spinacia oleracea/citología , Spinacia oleracea/metabolismo
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