NAC family genes encode plant-specific transcription factors involved in diverse biological processes. In this study, the Arabidopsis NAC gene ATAF1 was found to be induced by drought, high-salinity, abscisic acid （...NAC family genes encode plant-specific transcription factors involved in diverse biological processes. In this study, the Arabidopsis NAC gene ATAF1 was found to be induced by drought, high-salinity, abscisic acid （ABA）, methyl jasmonate, mechanical wounding, and Botrytis cinerea infection. Significant induction of ATAF1 was found in an ABA-deficient mutant aba2 subjected to drought or high salinity, revealing an ABA-independent mechanism of expression. Arabidopsis ATAFl-overexpression lines displayed many altered phenotypes, including dwarfism and short primary roots. Furthermore, in vivo experiments indicate that ATAF1 is a bonafide regulator modulating plant responses to many abiotic stresses and necrotrophic-pathogen infection. Overexpression of ATAF1 in Arabidopsis increased plant sensitivity to ABA, salt, and oxidative stresses. Especially, ATAF1 overexpression plants, but not mutant lines, showed remarkably enhanced plant tolerance to drought. Additionally, ATAF1 overexpression enhanced plant susceptibility to the necrotrophic pathogen B. cinerea, but did not alter disease symptoms caused by avirulent or virulent strains of P. syringae pv tomato DC3000. Transgenic plants overexpressing ATAF1 were hypersensitive to oxidative stress, suggesting that reactive oxygen intermediates may be related to ATAFl-mediated signaling in response to both pathogen and abiotic stresses.展开更多
AIM: To investigate the role of heme oxygenase-1 (HO-1) in pathogenesis of experimental hepatorenal syndrome (HRS). METHODS: Rats were divided into liver cirrhotic group, zinc protoporphyrin IX (ZnPP) treatment group,...AIM: To investigate the role of heme oxygenase-1 (HO-1) in pathogenesis of experimental hepatorenal syndrome (HRS). METHODS: Rats were divided into liver cirrhotic group, zinc protoporphyrin IX (ZnPP) treatment group, cobalt protoporphyrin (CoPP) treatment group and sham group. Biliary cirrhosis was established by bile duct ligation in the first three groups. Rats in the ZnPP and CoPP treatment groups received intraperitoneal injection of ZnPP and CoPP, respectively, 24 h before sample collection. Expression of HO-1 mRNA in kidney was detected by reverse-transcription polymerase chain reaction, while protein expression was determined by immunohis-tochemical analysis. Hematoxylin and eosin staining was performed to observe liver cirrhosis and renal structure. Renal artery blood flow, mean arterial pressure and portal vein pressure, 24 h total urinary volume, serum and urine sodium concentrations, and creatinine clearance rate (Ccr) were also measured.RESULTS: The HO-1 mRNA and protein expression levels in kidney, 24 h total urinary volume, renal artery blood flow, serum and urine sodium concentration and Ccr were lower in cirrhotic group than in sham group (P < 0.05). However, they were significantly lower in ZnPP treatment group than in cirrhotic group and significantly higher in CoPP treatment group than in cirrhotic group (P < 0.05). CONCLUSION: Low HO-1 expression level in kidney is an important factor for experimental HRS.展开更多
AIM:To study the production and secretion of corticotropin-releasing factor (CRF) by dendritic cells and the influence of commensal bacteria.METHODS:JAWSⅡ cells (ATCC CRL-11904),a mouse dendritic cell line,were seede...AIM:To study the production and secretion of corticotropin-releasing factor (CRF) by dendritic cells and the influence of commensal bacteria.METHODS:JAWSⅡ cells (ATCC CRL-11904),a mouse dendritic cell line,were seeded into 24-well culture plates and grown for 3 d.Commensal bacterial strains of Clostridium clostrodiiforme (JCM1291),Bacteroides vulgatus (B.vulgatus) (JCM5856),Escherichia coli (JCM1649),or Fusobacterium varium (F.varium) (ATCC8501) were added to the cells except for the control well,and incubated for 2 h.After incubation,we performed enzyme-linked immunosorbent assay for the cultured medium and reverse transcription polymerase chain reaction for the dendritic cells,and compared these values with controls.RESULTS:The level of CRF secretion by control dendritic cells was 40.4±6.2 pg/mL.The CRF levels for cells incubated with F.varium and B.vulgatus were significantly higher than that of the control (P<0.0001).CRF mRNA was present in the control sample without bacteria,and CRF mRNA levels in all samples treated with bacteria were above that of the control sample.F.varium caused the greatest increase in CRF mRNA expression.CONCLUSION:Our results suggest that dendritic cells produce CRF,a process augmented by commensal bacteria.展开更多
基金We would like to thank Dr Nam-Hai Chua （Rockefeller Univer- sity） for kindly providing the pBA002Myc vector and the Arabi- dopsis Biological Resource Center （ABRC）, Ohio State University for providing ToDNA insertion lines. This work was supported by grants from National Natural Science Foundation of China （No. 30530400/90717006/30670195） to Q Xie and Y Wu, the Chinese Academy of Science （KSCX2-YW-N-010 and CXTD-S2005-2）, and the （iuangdong Natural Science Foundation, China （No. 5300648） to Z Deng.
文摘NAC family genes encode plant-specific transcription factors involved in diverse biological processes. In this study, the Arabidopsis NAC gene ATAF1 was found to be induced by drought, high-salinity, abscisic acid （ABA）, methyl jasmonate, mechanical wounding, and Botrytis cinerea infection. Significant induction of ATAF1 was found in an ABA-deficient mutant aba2 subjected to drought or high salinity, revealing an ABA-independent mechanism of expression. Arabidopsis ATAFl-overexpression lines displayed many altered phenotypes, including dwarfism and short primary roots. Furthermore, in vivo experiments indicate that ATAF1 is a bonafide regulator modulating plant responses to many abiotic stresses and necrotrophic-pathogen infection. Overexpression of ATAF1 in Arabidopsis increased plant sensitivity to ABA, salt, and oxidative stresses. Especially, ATAF1 overexpression plants, but not mutant lines, showed remarkably enhanced plant tolerance to drought. Additionally, ATAF1 overexpression enhanced plant susceptibility to the necrotrophic pathogen B. cinerea, but did not alter disease symptoms caused by avirulent or virulent strains of P. syringae pv tomato DC3000. Transgenic plants overexpressing ATAF1 were hypersensitive to oxidative stress, suggesting that reactive oxygen intermediates may be related to ATAFl-mediated signaling in response to both pathogen and abiotic stresses.
基金Supported by National Natural Science Foundation of China, No. 30970886Science and Technology Project of Dalian,No. 2008E13SF193
文摘AIM: To investigate the role of heme oxygenase-1 (HO-1) in pathogenesis of experimental hepatorenal syndrome (HRS). METHODS: Rats were divided into liver cirrhotic group, zinc protoporphyrin IX (ZnPP) treatment group, cobalt protoporphyrin (CoPP) treatment group and sham group. Biliary cirrhosis was established by bile duct ligation in the first three groups. Rats in the ZnPP and CoPP treatment groups received intraperitoneal injection of ZnPP and CoPP, respectively, 24 h before sample collection. Expression of HO-1 mRNA in kidney was detected by reverse-transcription polymerase chain reaction, while protein expression was determined by immunohis-tochemical analysis. Hematoxylin and eosin staining was performed to observe liver cirrhosis and renal structure. Renal artery blood flow, mean arterial pressure and portal vein pressure, 24 h total urinary volume, serum and urine sodium concentrations, and creatinine clearance rate (Ccr) were also measured.RESULTS: The HO-1 mRNA and protein expression levels in kidney, 24 h total urinary volume, renal artery blood flow, serum and urine sodium concentration and Ccr were lower in cirrhotic group than in sham group (P < 0.05). However, they were significantly lower in ZnPP treatment group than in cirrhotic group and significantly higher in CoPP treatment group than in cirrhotic group (P < 0.05). CONCLUSION: Low HO-1 expression level in kidney is an important factor for experimental HRS.
基金Supported by Grants in Aid for Scientific Research (C) from the Japanese Ministry of Education,Culture,Sports,Science and Technology,No. 17590679
文摘AIM:To study the production and secretion of corticotropin-releasing factor (CRF) by dendritic cells and the influence of commensal bacteria.METHODS:JAWSⅡ cells (ATCC CRL-11904),a mouse dendritic cell line,were seeded into 24-well culture plates and grown for 3 d.Commensal bacterial strains of Clostridium clostrodiiforme (JCM1291),Bacteroides vulgatus (B.vulgatus) (JCM5856),Escherichia coli (JCM1649),or Fusobacterium varium (F.varium) (ATCC8501) were added to the cells except for the control well,and incubated for 2 h.After incubation,we performed enzyme-linked immunosorbent assay for the cultured medium and reverse transcription polymerase chain reaction for the dendritic cells,and compared these values with controls.RESULTS:The level of CRF secretion by control dendritic cells was 40.4±6.2 pg/mL.The CRF levels for cells incubated with F.varium and B.vulgatus were significantly higher than that of the control (P<0.0001).CRF mRNA was present in the control sample without bacteria,and CRF mRNA levels in all samples treated with bacteria were above that of the control sample.F.varium caused the greatest increase in CRF mRNA expression.CONCLUSION:Our results suggest that dendritic cells produce CRF,a process augmented by commensal bacteria.
