Termination of translation in eukaryotes requires two polypeptide chain-release factors, eRF1 and eRF3. eRF1 recognizes stop signals, whereas eRF3 is a ribosome-dependent and eRFl-dependent GTPase. Polypeptide release...Termination of translation in eukaryotes requires two polypeptide chain-release factors, eRF1 and eRF3. eRF1 recognizes stop signals, whereas eRF3 is a ribosome-dependent and eRFl-dependent GTPase. Polypeptide release factor eRF3 consists of N-terminal variable region and C-terminal conserved part. C-terminal part of eRF3 is responsible for termination of the translation, In the present study, the C-terminal of Euplotes octocarinatus eRF3 (eRF3C) and truncate eRF3C lacking 76 amino acids in C-terminal (eRF3Ct) were expressed in Escherichia coll. The recombinant GST-eRF3C and GST-eRF3Ct polypeptides were purifled by affinity chromatography using glutathione Sepharose 4B column. After enzymatic cleavage of GST tail, the eRF3C and eRF3Ct protein were obtained. Pull-down analysis showed that the recombinant GST-eRF3C and GST-eRF3Ct polypeptides interacted with E. octocarinatus polypeptide chain release factor eRF1a. This result suggested that the C-terminal of eRF3 having 76 amino acids were not required for the binding of eRFla in Euplotes octocarinatus.展开更多
The fracture theory of cubic quasicrystal was developed. The exact analytic solution of a Mode Ⅲ Griffith crack in the material was obtained by using the Fourier transform and dual integral equations theory, and so t...The fracture theory of cubic quasicrystal was developed. The exact analytic solution of a Mode Ⅲ Griffith crack in the material was obtained by using the Fourier transform and dual integral equations theory, and so the displacement and stress fields, the stress intensity factor and strain energy release rate were determined. The results show that the stress intensity factor is independent of material constants, and the strain energy release rate is dependent on all material constants. These provide important information for studying the deformation and fracture of the new solid material.展开更多
Objective: To study the protective and therapeutic antitumor immunity against hepatocellular carcinoma (HCC) with the fixed-tumor vaccine.Methods: A tumor vaccine consisting of fixed tumor cells or fixed tumor fragmen...Objective: To study the protective and therapeutic antitumor immunity against hepatocellular carcinoma (HCC) with the fixed-tumor vaccine.Methods: A tumor vaccine consisting of fixed tumor cells or fixed tumor fragments combined with sustained-releasers of cytokines and a non-toxic adjuvant was developed. C57BL/6J mice were immunized intra-dermally with the vaccine on day 0 and 7, followed by intrahepatic challenge with live Hepa 1–6 cells.Results: All of 15 nonimmunized control mice developed the hepatoma. Protection of mice immunized with fixed Hepa 1–6 cells and both of IL-2/GM-CSF microspheres or further mixed with TiterMax Gold reached 80% and 87%, respectively. Mass growth of the established tumors, vaccinated twice at 5 mm in diameter, the tumor of control animals continued to grow. However, 7–10 days after the second injection of the tumor vaccine, the tumor growth was suppressed in 9 of 10 mice and then markedly reduced. Complete tumor regression was observed in 60% (6/10) of mice. Splenocytes from the control mice were not able to lyse target Hepa 1–6 cells and other tumor cells. In contrast splenocytes from the vaccinated mice exhibited a 41% lytic activity against the Hepa 1–6 cells tested at an effector/target (E/T) ratio of 5, whereas they did not exhibited such activity against the melanoma cells (B16-F1), Lewis lung carcinoma cells (LLC), renal carcinoma cells (Renca), and bladder carcinoma cells (MBT-2). The cytotoxic activity was inhibited by the treatment with anti-CD3, anti-CD8, and anti-MHC-class I monoclonal antibodies but not with anti-CD4 and anti-MHC-class II antibodies. In the Phase-I clinical trial, vaccination of HCC patients with the autologous vaccine is a well-tolerated treatment and induces fixed tumor fragment-specific immunity.Conclusion: Fixed HCC vaccination elicited protective and therapeutic antitumor immunity against HCC. The tumor vaccine elicited antigen specific CTL response lysis of the target HCC was mediated by the typical MHC-class I restricted CD8+ T cells. Key words cancer vaccine - cytotoxic T lymphocyte - immunotherapy - hepatoma展开更多
[Objective] The aim was to study the release characteristics of different release-controlled fertilizers, as well as their effects on wheat growth and develop- ment under water stress. [method] With phosphorus-potassi...[Objective] The aim was to study the release characteristics of different release-controlled fertilizers, as well as their effects on wheat growth and develop- ment under water stress. [method] With phosphorus-potassium fertilization and opti- mized fertilization (OPT) as the control, the release characteristics of 4 kinds of re- lease-controlled nitrogen fertilizers (A, B, C and D) coated with different materials were studied. [Result] Under the same phosphorus and potassium levels, the re- lease-controlled nitrogen fertilizers A and B significantly improved the yield of wheat. Spike number is the main reason leading to the difference in yield. The fertilizers A and B were released by 44.4% and 46.3% before winter, released by 72.1% and 69.8% at the jointing stage, and related by 88.0% and 91.5% in the harvest period, meeting the nitrogen requirement of dryland wheat across the growth period. Com- pared with OPT, the nitrogen accumulation amounts in treatments A and B were increased by 1.39 and 2.09 kg/667 m2, the nitrogen use efficiencies were increased by 8.66% and 13.04%, and the nitrogen partial factor productivities were increased by 9.00 and 7.22 kg/kg, respectively. [Conclusion] Among the 4 kinds of fertilizers, A and B were considered as the optimum release-controlled nitrogen fertilizers for winter wheat on dry land.展开更多
[Objective] This study was to clone the GnRH (gonadotropin-releasing hormone), and to investigate its expression in Apis cerana cerana. [Method] The cDNA sequence of GnRHR gene was amplified from Apis cerana cerana ...[Objective] This study was to clone the GnRH (gonadotropin-releasing hormone), and to investigate its expression in Apis cerana cerana. [Method] The cDNA sequence of GnRHR gene was amplified from Apis cerana cerana by using RT-PCR techniques. It was conducted with bioinformatics analysis and the in situ hybridization histochemistry of its expression products was studied. [Result] The sequence analy- sis showed that the full cDNA sequence was 1 050 bp with the open reading frame of 1 050 bp, and it encoded 349 amino acid residues. The deduced amino sequence included 7 transmembrane regions, and the predicted molecular mass and isoelectric point were 40.6 kD and 9.54, respectively. The cluster analysis showed that the GnRHR from ',4. cerana cerana had close relationship to the GnRHR II from other insects. In situ hybridization showed that Bee-GnRHR staining was specifically localized to the brain, intestine, fat body and testis. [Conclusion] The results indicated that the GnRHR provided molecular bond for the reproduction and metabolism for insects, and suggested a functional role for bee-GnRHR signaling in the coupling of reproduction activities and environment conditions.展开更多
Attenuated adenomatous polyposis(AAP) is a poorly understood syndrome, that can be defined as the presence of 10-99 synchronous adenomas in the large bowel, and it is considered a phenotypic variant of familial adenom...Attenuated adenomatous polyposis(AAP) is a poorly understood syndrome, that can be defined as the presence of 10-99 synchronous adenomas in the large bowel, and it is considered a phenotypic variant of familial adenomatous polyposis(FAP). This definition has the advantage of simplicity, but it may include sporadic multiple adenomas of the large bowel at an extreme, or FAP cases on the other side. AAP shows a milder phenotype than FAP, with an older age of onset of adenomas and cancer, and less frequent extracolonic manifestations. AAP may be diagnosed as a single case in a family or, less frequently, it may be present in other family members, and it shows distinct pattern of inheritance. In less than 50% of cases, it may be caused by adenomatous polyposis coli(APC) or MUTYH mutations, referred to as APC-associated polyposis, inherited as an autosomal dominant trait, or MUTYH-associated polyposis, which shows an autosomal recessive mechanism of inheritance, respectively. Surveillance should rely on colonoscopy at regular intervals, with removal of adenomas and careful histological examination. When removal of polyps is not possible or advanced lesions are observed, the surgical approach is mandatory, being subtotal colectomy with ileo-rectal anastomosis the treatment of choice. Studies on this syndrome are lacking, and controversies are still present on many issues, thus, other clinical and genetic studies are requested.展开更多
To determine the role of corticotropin releasing factor receptor (CRF2) in epithelial permeability and enterocyte cell differentiation.METHODSFor this purpose, we used rat Sprague Dawley and various colon carcinoma ce...To determine the role of corticotropin releasing factor receptor (CRF2) in epithelial permeability and enterocyte cell differentiation.METHODSFor this purpose, we used rat Sprague Dawley and various colon carcinoma cell lines (SW620, HCT8R, HT-29 and Caco-2 cell lines). Expression of CRF2 protein was analyzed by fluorescent immunolabeling in normal rat colon and then by western blot in dissociated colonic epithelial cells and in the lysates of colon carcinoma cell lines or during the early differentiation of HT-29 cells (ten first days). To assess the impact of CRF2 signaling on colonic cell differentiation, HT-29 and Caco-2 cells were exposed to Urocortin 3 recombinant proteins (Ucn3, 100 nmol/L). In some experiments, cells were pre-exposed to the astressin 2b (A2b) a CRF2 antagonist in order to inhibit the action of Ucn3. Intestinal cell differentiation was first analyzed by functional assays: the trans-cellular permeability and the para-cellular permeability were determined by Dextran-FITC intake and measure of the transepithelial electrical resistance respectively. Morphological modifications associated to epithelial dysfunction were analyzed by confocal microscopy after fluorescent labeling of actin (phaloidin-TRITC) and intercellular adhesion proteins such as E-cadherin, p120ctn, occludin and ZO-1. The establishment of mature adherens junctions (AJ) was monitored by following the distribution of AJ proteins in lipid raft fractions, after separation of cell lysates on sucrose gradients. Finally, the mRNA and the protein expression levels of characteristic markers of intestinal epithelial cell (IEC) differentiation such as the transcriptional factor krüppel-like factor 4 (KLF4) or the dipeptidyl peptidase IV (DPPIV) were performed by RT-PCR and western blot respectively. The specific activities of DPPIV and alkaline phosphatase (AP) enzymes were determined by a colorimetric method.RESULTSCRF2 protein is preferentially expressed in undifferentiated epithelial cells from the crypts of colon and in human colon carcinoma cell lines. Furthermore, CRF2 expression is down regulated according to the kinetic of HT-29 cell differentiation. By performing functional assays, we found that Ucn3-induced CRF2 signaling alters both para- and trans-cellular permeability of differentiated HT-29 and Caco-2 cells. These effects are partly mediated by Ucn3-induced morphological changes associated with the disruption of mature AJ in HT-29 cells and tight junctions (TJ) in Caco-2 cells. Ucn3-mediated activation of CRF2 decreases mRNA and protein expression levels of KLF4 a transcription factor involved in IEC differentiation. This signaling is correlated to a down-regulation of key IEC markers such as DPPIV and AP, at both transcriptional and post-transcriptional levels.CONCLUSIONOur findings suggest that CRF2 signaling could modulate IEC differentiation. These mechanisms could be relevant to the stress induced epithelial alterations found in inflammatory bowel diseases.展开更多
The onset of alcoholic liver disease (ALD) is initiated by different cell types in the liver and a number of different factors including: products derived from ethanol-induced inflammation, ethanol metabolites, and th...The onset of alcoholic liver disease (ALD) is initiated by different cell types in the liver and a number of different factors including: products derived from ethanol-induced inflammation, ethanol metabolites, and the indirect reactions from those metabolites. Ethanol oxidation results in the production of metabolites that have been shown to bind and form protein adducts, and to increase inflammatory, fibrotic and cirrhotic responses. Lipopolysaccharide (LPS) has many deleterious effects and plays a significant role in a number of disease processes by increasing inflammatory cytokine release. In ALD, LPS is thought to be derived from a breakdown in the intestinal wall enabling LPS from resident gut bacterial cell walls to leak into the blood stream. The ability of adducts and LPS to independently stimulate the various cells of the liver provides for a two-hit mechanism by which various biological responses are induced and result in liver injury. Therefore, the purpose of this article is to evaluate the effects of a two-hit combination of ethanol metabolites and LPS on the cells of the liver to increase inflamma-tion and fi brosis, and play a role in the development and/or progression of ALD.展开更多
Kallikrein 8 (KLK8) is a serine protease functioning in the central nervous system, and essential in many aspects of neuronal activities. Sequence comparison and gene expression analysis among diverse primate specie...Kallikrein 8 (KLK8) is a serine protease functioning in the central nervous system, and essential in many aspects of neuronal activities. Sequence comparison and gene expression analysis among diverse primate species identified a human-specific splice form of KLK8 (type II) with preferential expression in the human brain, which may contribute to the origin of human cognition. To gain insights into the physiological and biochemical role of this novel form, we conducted functional analyses of human type II KLK8. Our results show that type II KLK8 is abundantly expressed in human embryonic stem cells and in embryo brain samples, suggesting a potential role in embryogenesis. There are dramatic expression variations in different individuals and brain regions, which is a reflection of its dynamic role in neural activities. Furthermore, the transcription start site (TSS) of KLK8 is tissue-specific, with a brain-specific TSS found in humans indicating functional specialization. Our in vitro biochemical assay shows that there is a type II-specific intermediate protein form, although the processed end-point enzymes are the same for both type 1 and type II KLK8, suggesting that the emergence of type II KLK8 in the human brain likciy leads to functional modifications of KLK8.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This work was supported by grants from National Natural Science Foundation of China(No.30670282,30470239,3030038)Natural Science Foundation of Shanxi Province(No.20041079,20051065).
文摘Termination of translation in eukaryotes requires two polypeptide chain-release factors, eRF1 and eRF3. eRF1 recognizes stop signals, whereas eRF3 is a ribosome-dependent and eRFl-dependent GTPase. Polypeptide release factor eRF3 consists of N-terminal variable region and C-terminal conserved part. C-terminal part of eRF3 is responsible for termination of the translation, In the present study, the C-terminal of Euplotes octocarinatus eRF3 (eRF3C) and truncate eRF3C lacking 76 amino acids in C-terminal (eRF3Ct) were expressed in Escherichia coll. The recombinant GST-eRF3C and GST-eRF3Ct polypeptides were purifled by affinity chromatography using glutathione Sepharose 4B column. After enzymatic cleavage of GST tail, the eRF3C and eRF3Ct protein were obtained. Pull-down analysis showed that the recombinant GST-eRF3C and GST-eRF3Ct polypeptides interacted with E. octocarinatus polypeptide chain release factor eRF1a. This result suggested that the C-terminal of eRF3 having 76 amino acids were not required for the binding of eRFla in Euplotes octocarinatus.
文摘The fracture theory of cubic quasicrystal was developed. The exact analytic solution of a Mode Ⅲ Griffith crack in the material was obtained by using the Fourier transform and dual integral equations theory, and so the displacement and stress fields, the stress intensity factor and strain energy release rate were determined. The results show that the stress intensity factor is independent of material constants, and the strain energy release rate is dependent on all material constants. These provide important information for studying the deformation and fracture of the new solid material.
文摘Objective: To study the protective and therapeutic antitumor immunity against hepatocellular carcinoma (HCC) with the fixed-tumor vaccine.Methods: A tumor vaccine consisting of fixed tumor cells or fixed tumor fragments combined with sustained-releasers of cytokines and a non-toxic adjuvant was developed. C57BL/6J mice were immunized intra-dermally with the vaccine on day 0 and 7, followed by intrahepatic challenge with live Hepa 1–6 cells.Results: All of 15 nonimmunized control mice developed the hepatoma. Protection of mice immunized with fixed Hepa 1–6 cells and both of IL-2/GM-CSF microspheres or further mixed with TiterMax Gold reached 80% and 87%, respectively. Mass growth of the established tumors, vaccinated twice at 5 mm in diameter, the tumor of control animals continued to grow. However, 7–10 days after the second injection of the tumor vaccine, the tumor growth was suppressed in 9 of 10 mice and then markedly reduced. Complete tumor regression was observed in 60% (6/10) of mice. Splenocytes from the control mice were not able to lyse target Hepa 1–6 cells and other tumor cells. In contrast splenocytes from the vaccinated mice exhibited a 41% lytic activity against the Hepa 1–6 cells tested at an effector/target (E/T) ratio of 5, whereas they did not exhibited such activity against the melanoma cells (B16-F1), Lewis lung carcinoma cells (LLC), renal carcinoma cells (Renca), and bladder carcinoma cells (MBT-2). The cytotoxic activity was inhibited by the treatment with anti-CD3, anti-CD8, and anti-MHC-class I monoclonal antibodies but not with anti-CD4 and anti-MHC-class II antibodies. In the Phase-I clinical trial, vaccination of HCC patients with the autologous vaccine is a well-tolerated treatment and induces fixed tumor fragment-specific immunity.Conclusion: Fixed HCC vaccination elicited protective and therapeutic antitumor immunity against HCC. The tumor vaccine elicited antigen specific CTL response lysis of the target HCC was mediated by the typical MHC-class I restricted CD8+ T cells. Key words cancer vaccine - cytotoxic T lymphocyte - immunotherapy - hepatoma
基金Supported by Scientific and Technological Development Plan of Shandong Province(2014GNC113001)Open Subject of National Key Laboratory of Crop Biology(2014KF11)Science and Technology Plan Project of Tai'an City~~
文摘[Objective] The aim was to study the release characteristics of different release-controlled fertilizers, as well as their effects on wheat growth and develop- ment under water stress. [method] With phosphorus-potassium fertilization and opti- mized fertilization (OPT) as the control, the release characteristics of 4 kinds of re- lease-controlled nitrogen fertilizers (A, B, C and D) coated with different materials were studied. [Result] Under the same phosphorus and potassium levels, the re- lease-controlled nitrogen fertilizers A and B significantly improved the yield of wheat. Spike number is the main reason leading to the difference in yield. The fertilizers A and B were released by 44.4% and 46.3% before winter, released by 72.1% and 69.8% at the jointing stage, and related by 88.0% and 91.5% in the harvest period, meeting the nitrogen requirement of dryland wheat across the growth period. Com- pared with OPT, the nitrogen accumulation amounts in treatments A and B were increased by 1.39 and 2.09 kg/667 m2, the nitrogen use efficiencies were increased by 8.66% and 13.04%, and the nitrogen partial factor productivities were increased by 9.00 and 7.22 kg/kg, respectively. [Conclusion] Among the 4 kinds of fertilizers, A and B were considered as the optimum release-controlled nitrogen fertilizers for winter wheat on dry land.
基金Supported by the Science and Technology Planning Project of the Education Department of Shaanxi Province(11JK0618)~~
文摘[Objective] This study was to clone the GnRH (gonadotropin-releasing hormone), and to investigate its expression in Apis cerana cerana. [Method] The cDNA sequence of GnRHR gene was amplified from Apis cerana cerana by using RT-PCR techniques. It was conducted with bioinformatics analysis and the in situ hybridization histochemistry of its expression products was studied. [Result] The sequence analy- sis showed that the full cDNA sequence was 1 050 bp with the open reading frame of 1 050 bp, and it encoded 349 amino acid residues. The deduced amino sequence included 7 transmembrane regions, and the predicted molecular mass and isoelectric point were 40.6 kD and 9.54, respectively. The cluster analysis showed that the GnRHR from ',4. cerana cerana had close relationship to the GnRHR II from other insects. In situ hybridization showed that Bee-GnRHR staining was specifically localized to the brain, intestine, fat body and testis. [Conclusion] The results indicated that the GnRHR provided molecular bond for the reproduction and metabolism for insects, and suggested a functional role for bee-GnRHR signaling in the coupling of reproduction activities and environment conditions.
文摘Attenuated adenomatous polyposis(AAP) is a poorly understood syndrome, that can be defined as the presence of 10-99 synchronous adenomas in the large bowel, and it is considered a phenotypic variant of familial adenomatous polyposis(FAP). This definition has the advantage of simplicity, but it may include sporadic multiple adenomas of the large bowel at an extreme, or FAP cases on the other side. AAP shows a milder phenotype than FAP, with an older age of onset of adenomas and cancer, and less frequent extracolonic manifestations. AAP may be diagnosed as a single case in a family or, less frequently, it may be present in other family members, and it shows distinct pattern of inheritance. In less than 50% of cases, it may be caused by adenomatous polyposis coli(APC) or MUTYH mutations, referred to as APC-associated polyposis, inherited as an autosomal dominant trait, or MUTYH-associated polyposis, which shows an autosomal recessive mechanism of inheritance, respectively. Surveillance should rely on colonoscopy at regular intervals, with removal of adenomas and careful histological examination. When removal of polyps is not possible or advanced lesions are observed, the surgical approach is mandatory, being subtotal colectomy with ileo-rectal anastomosis the treatment of choice. Studies on this syndrome are lacking, and controversies are still present on many issues, thus, other clinical and genetic studies are requested.
基金Supported by grants from Association pour la Recherche sur le Cancer,Ligue Nationale contre le Cancer,No.GEFLUC and No.ESPOIR
文摘To determine the role of corticotropin releasing factor receptor (CRF2) in epithelial permeability and enterocyte cell differentiation.METHODSFor this purpose, we used rat Sprague Dawley and various colon carcinoma cell lines (SW620, HCT8R, HT-29 and Caco-2 cell lines). Expression of CRF2 protein was analyzed by fluorescent immunolabeling in normal rat colon and then by western blot in dissociated colonic epithelial cells and in the lysates of colon carcinoma cell lines or during the early differentiation of HT-29 cells (ten first days). To assess the impact of CRF2 signaling on colonic cell differentiation, HT-29 and Caco-2 cells were exposed to Urocortin 3 recombinant proteins (Ucn3, 100 nmol/L). In some experiments, cells were pre-exposed to the astressin 2b (A2b) a CRF2 antagonist in order to inhibit the action of Ucn3. Intestinal cell differentiation was first analyzed by functional assays: the trans-cellular permeability and the para-cellular permeability were determined by Dextran-FITC intake and measure of the transepithelial electrical resistance respectively. Morphological modifications associated to epithelial dysfunction were analyzed by confocal microscopy after fluorescent labeling of actin (phaloidin-TRITC) and intercellular adhesion proteins such as E-cadherin, p120ctn, occludin and ZO-1. The establishment of mature adherens junctions (AJ) was monitored by following the distribution of AJ proteins in lipid raft fractions, after separation of cell lysates on sucrose gradients. Finally, the mRNA and the protein expression levels of characteristic markers of intestinal epithelial cell (IEC) differentiation such as the transcriptional factor krüppel-like factor 4 (KLF4) or the dipeptidyl peptidase IV (DPPIV) were performed by RT-PCR and western blot respectively. The specific activities of DPPIV and alkaline phosphatase (AP) enzymes were determined by a colorimetric method.RESULTSCRF2 protein is preferentially expressed in undifferentiated epithelial cells from the crypts of colon and in human colon carcinoma cell lines. Furthermore, CRF2 expression is down regulated according to the kinetic of HT-29 cell differentiation. By performing functional assays, we found that Ucn3-induced CRF2 signaling alters both para- and trans-cellular permeability of differentiated HT-29 and Caco-2 cells. These effects are partly mediated by Ucn3-induced morphological changes associated with the disruption of mature AJ in HT-29 cells and tight junctions (TJ) in Caco-2 cells. Ucn3-mediated activation of CRF2 decreases mRNA and protein expression levels of KLF4 a transcription factor involved in IEC differentiation. This signaling is correlated to a down-regulation of key IEC markers such as DPPIV and AP, at both transcriptional and post-transcriptional levels.CONCLUSIONOur findings suggest that CRF2 signaling could modulate IEC differentiation. These mechanisms could be relevant to the stress induced epithelial alterations found in inflammatory bowel diseases.
文摘The onset of alcoholic liver disease (ALD) is initiated by different cell types in the liver and a number of different factors including: products derived from ethanol-induced inflammation, ethanol metabolites, and the indirect reactions from those metabolites. Ethanol oxidation results in the production of metabolites that have been shown to bind and form protein adducts, and to increase inflammatory, fibrotic and cirrhotic responses. Lipopolysaccharide (LPS) has many deleterious effects and plays a significant role in a number of disease processes by increasing inflammatory cytokine release. In ALD, LPS is thought to be derived from a breakdown in the intestinal wall enabling LPS from resident gut bacterial cell walls to leak into the blood stream. The ability of adducts and LPS to independently stimulate the various cells of the liver provides for a two-hit mechanism by which various biological responses are induced and result in liver injury. Therefore, the purpose of this article is to evaluate the effects of a two-hit combination of ethanol metabolites and LPS on the cells of the liver to increase inflamma-tion and fi brosis, and play a role in the development and/or progression of ALD.
文摘Kallikrein 8 (KLK8) is a serine protease functioning in the central nervous system, and essential in many aspects of neuronal activities. Sequence comparison and gene expression analysis among diverse primate species identified a human-specific splice form of KLK8 (type II) with preferential expression in the human brain, which may contribute to the origin of human cognition. To gain insights into the physiological and biochemical role of this novel form, we conducted functional analyses of human type II KLK8. Our results show that type II KLK8 is abundantly expressed in human embryonic stem cells and in embryo brain samples, suggesting a potential role in embryogenesis. There are dramatic expression variations in different individuals and brain regions, which is a reflection of its dynamic role in neural activities. Furthermore, the transcription start site (TSS) of KLK8 is tissue-specific, with a brain-specific TSS found in humans indicating functional specialization. Our in vitro biochemical assay shows that there is a type II-specific intermediate protein form, although the processed end-point enzymes are the same for both type 1 and type II KLK8, suggesting that the emergence of type II KLK8 in the human brain likciy leads to functional modifications of KLK8.
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.