AIM:To evaluate the protective effects of fucoidan on oxidative stress-induced barrier disruption in human intestinal epithelial cells.METHODS:In Caco-2 cell monolayer models,the disruption of barrier function by oxid...AIM:To evaluate the protective effects of fucoidan on oxidative stress-induced barrier disruption in human intestinal epithelial cells.METHODS:In Caco-2 cell monolayer models,the disruption of barrier function by oxidative stress is mediated by H2O2.The integrity of polarized Caco-2 cell monolayers was determined by measuring the transepithelial resistance(TER)and permeability was estimated by measuring the paracellular transport of FITC-labeled4-kDa dextran(FD4).The protective effects of fucoidan on epithelial barrier functions on polarized Caco-2 cell monolayers were evaluated by TER and FD4 flux.The expression of tight junction(TJ)proteins was assessed using reverse-transcription polymerase chain reaction(RT-PCR)and immunofluorescence staining.RESULTS:Without H2O2treatment,fucoidan significantly increased the TER compared to control(P<0.05),indicating a direct enhancement of intestinal epithelial barrier function.Next,H2O2disrupted the epithelial barrier function in a time-dependent manner.Fucoidan prevented the H2O2-induced destruction in a dosedependent manner.Fucoidan significantly decreased H2O2-induced FD4 flux(P<0.01),indicating the prevention of disruption in paracellular permeability.RTPCR showed that Caco-2 cells endogenously expressed claudin-1 and-2,and occludin and that H2O2reduced the mRNA expression of these TJ proteins.Treatment with fucoidan attenuated the reduction in the expressions of claudin-1 and claudin-2 but not occludin.Immunofluorescence staining revealed that the expression of claudin-1 was intact and high on the cell surface.H2O2disrupted the integrity of claudin-1.Treatment with fucoidan dramatically attenuated the expression of claudin-1.CONCLUSION:Fucoidan enhanced intestinal epithelial barrier function by upregulating the expression of claudin-1.Thus,fucoidan may be an appropriate therapy for the treatment of inflammatory bowel diseases.展开更多
AIM: To evaluate a multiplex PCR assay for the detection of bacterial and viral enteropathogens in stool samples from patients with ulcerative colitis(UC). METHODS: We prospectively analyzed 300 individuals, including...AIM: To evaluate a multiplex PCR assay for the detection of bacterial and viral enteropathogens in stool samples from patients with ulcerative colitis(UC). METHODS: We prospectively analyzed 300 individuals, including immunocompetent patients, immunocompromised patients, and patients with UC. Stool samples were collected from the recto-sigmoid region of the colon by endoscopy. The samples were qualitatively analyzed for bacterial and viral enteropathogens with a multiplex PCR assay using a Seeplex® Kit. Additional clinical and laboratory data were collected from the medical records. RESULTS: A multiplex PCR assay detected 397 pathogens(191 bacteria and 206 viruses) in 215 samples(71.7%). The most frequently detected bacteria were Escherichia coli H7, 85(28.3%); followed by Aeromonas spp., 43(14.3%); and Clostridium perfringens, 36(12.0%) samples. The most prevalent viruses were Epstein-Barr virus(EBV), 90(30.0%); followed by human herpes virus-6(HHV-6), 53(17.7%); and cytomegalovirus(CMV), 37(12.3%) samples. The prevalence rate of CMV infection was significantly higher in the immunocompromised group than in the immunocompetent group(P < 0.01). CMV infection was more common in patients with UC(26/71; 36.6%)than in the immunocompetent patients excluding UC(6/188; 3.2%)(P < 0.01). CMV infection was more prevalent in UC active patients(25/58; 43.1%) than in UC inactive patients(1/13; 7.7%)(P < 0.05). Among 4 groups which defined by the UC activity and immunosuppressive drugs, the prevalence rate of CMV infection was highest in the UC active patients with immunosuppressive drugs(19/34; 55.8%). EpsteinBarr virus(EBV) infection was more common in the immunocompromised patients excluding UC(18/41; 43.9%) than in the immunocompetent patients excluding UC(47/188; 25.0%)(P < 0.05). The simultaneous presence of CMV and EBV and/or HHV6 in UC active patients(14/58; 24.1%) was greater than in immunocompromised patients excluding UC(5/41; 12.2%)(P < 0.05). CONCLUSION: The multiplex PCR assay that was used to analyze the stool samples in this study may serve as a non-invasive approach that can be used to exclude the possibility of CMV infection in patients with active UC who are treated with immunosuppressive therapy.展开更多
文摘AIM:To evaluate the protective effects of fucoidan on oxidative stress-induced barrier disruption in human intestinal epithelial cells.METHODS:In Caco-2 cell monolayer models,the disruption of barrier function by oxidative stress is mediated by H2O2.The integrity of polarized Caco-2 cell monolayers was determined by measuring the transepithelial resistance(TER)and permeability was estimated by measuring the paracellular transport of FITC-labeled4-kDa dextran(FD4).The protective effects of fucoidan on epithelial barrier functions on polarized Caco-2 cell monolayers were evaluated by TER and FD4 flux.The expression of tight junction(TJ)proteins was assessed using reverse-transcription polymerase chain reaction(RT-PCR)and immunofluorescence staining.RESULTS:Without H2O2treatment,fucoidan significantly increased the TER compared to control(P<0.05),indicating a direct enhancement of intestinal epithelial barrier function.Next,H2O2disrupted the epithelial barrier function in a time-dependent manner.Fucoidan prevented the H2O2-induced destruction in a dosedependent manner.Fucoidan significantly decreased H2O2-induced FD4 flux(P<0.01),indicating the prevention of disruption in paracellular permeability.RTPCR showed that Caco-2 cells endogenously expressed claudin-1 and-2,and occludin and that H2O2reduced the mRNA expression of these TJ proteins.Treatment with fucoidan attenuated the reduction in the expressions of claudin-1 and claudin-2 but not occludin.Immunofluorescence staining revealed that the expression of claudin-1 was intact and high on the cell surface.H2O2disrupted the integrity of claudin-1.Treatment with fucoidan dramatically attenuated the expression of claudin-1.CONCLUSION:Fucoidan enhanced intestinal epithelial barrier function by upregulating the expression of claudin-1.Thus,fucoidan may be an appropriate therapy for the treatment of inflammatory bowel diseases.
文摘AIM: To evaluate a multiplex PCR assay for the detection of bacterial and viral enteropathogens in stool samples from patients with ulcerative colitis(UC). METHODS: We prospectively analyzed 300 individuals, including immunocompetent patients, immunocompromised patients, and patients with UC. Stool samples were collected from the recto-sigmoid region of the colon by endoscopy. The samples were qualitatively analyzed for bacterial and viral enteropathogens with a multiplex PCR assay using a Seeplex® Kit. Additional clinical and laboratory data were collected from the medical records. RESULTS: A multiplex PCR assay detected 397 pathogens(191 bacteria and 206 viruses) in 215 samples(71.7%). The most frequently detected bacteria were Escherichia coli H7, 85(28.3%); followed by Aeromonas spp., 43(14.3%); and Clostridium perfringens, 36(12.0%) samples. The most prevalent viruses were Epstein-Barr virus(EBV), 90(30.0%); followed by human herpes virus-6(HHV-6), 53(17.7%); and cytomegalovirus(CMV), 37(12.3%) samples. The prevalence rate of CMV infection was significantly higher in the immunocompromised group than in the immunocompetent group(P < 0.01). CMV infection was more common in patients with UC(26/71; 36.6%)than in the immunocompetent patients excluding UC(6/188; 3.2%)(P < 0.01). CMV infection was more prevalent in UC active patients(25/58; 43.1%) than in UC inactive patients(1/13; 7.7%)(P < 0.05). Among 4 groups which defined by the UC activity and immunosuppressive drugs, the prevalence rate of CMV infection was highest in the UC active patients with immunosuppressive drugs(19/34; 55.8%). EpsteinBarr virus(EBV) infection was more common in the immunocompromised patients excluding UC(18/41; 43.9%) than in the immunocompetent patients excluding UC(47/188; 25.0%)(P < 0.05). The simultaneous presence of CMV and EBV and/or HHV6 in UC active patients(14/58; 24.1%) was greater than in immunocompromised patients excluding UC(5/41; 12.2%)(P < 0.05). CONCLUSION: The multiplex PCR assay that was used to analyze the stool samples in this study may serve as a non-invasive approach that can be used to exclude the possibility of CMV infection in patients with active UC who are treated with immunosuppressive therapy.
