No abstract available.
Gastroesophageal Reflux* ; Humans ; Intercellular Junctions* ; Tight Junction Proteins*

OBJECTIVE: To study the effects of respiratory syncytial virus (RSV) infection on epidermal growth factor receptor (EGFR), tight junction association proteins and mucin in the human airway epithelial cells. METHODS: Human airway epithelial cells NCI-H292 were randomly treated by ultraviolet light-inactivated RSV (control group) or thawed RSV (RSV infection group). After 48 hours of treatment, the protein levels of occludin, E-cadherin, phosphorylated EGFR and EGFR in NCI-H292 cells were measured by Western blot. The distribution and expression levels of occludin and E-cadherin in NCI-H292 cells were examined by immunofluorescence technique. The expression levels of MUC5AC mRNA in NCI-H292 cells were assessed by RT-PCR. RESULTS: The protein levels of occludin and E-cadherin were significantly reduced in the RSV infection group compared with the control group (P<0.05). The protein levels of phosphorylated EGFR and EGFR increased significantly in the RSV infection group compared with the control group (P<0.05). The MUC5AC mRNA levels also increased significantly in the RSV infection group compared with the control group (P<0.05). CONCLUSIONS RSV may down-regulate the tight junction association proteins and up-regulate the expression of MUC5AC in airway epithelial cells, which contributes to epithelial barrier dysfunction. EGFR phosphorylation may play an important role in regulation of airway barrier.
Cell Line ; Epithelial Cells ; ErbB Receptors ; Humans ; Mucin 5AC ; Respiratory Syncytial Virus Infections ; Tight Junction Proteins ; Tight Junctions

BACKGROUND/AIMS: Detailed characterization of the ultrastructural morphology of intercellular space in gastroesophageal reflux disease has not been fully studied. We aimed to investigate whether subtle alteration in intercellular space structure and tight junction proteins might differ among patients with gastroesophageal reflux disease. METHODS: Esophageal biopsies at 5 cm above the gastroesophageal junction were obtained from 6 asymptomatic controls, 10 patients with reflux symptoms but without erosions, and 18 patients with erosions. The biopsies were morphologically evaluated by transmission electron microscopy, and by using immunohistochemistry for tight junction proteins (claudin-1 and claudin-2 proteins). RESULTS: The expressions of tight junction proteins did not differ between asymptomatic controls and gastroesophageal reflux disease patients. In patients with gastroesophageal reflux disease, altered desmosomal junction morphology was only found in upper stratified squamous epithelium. Dilated intercellular space occurred only in upper stratified squamous epithelium and in patients with erosive esophagitis. CONCLUSIONS: This study suggests that dilated intercellular space may not be uniformly present inside the esophageal mucosa and predominantly it is located in upper squamous epithelium. Presence of desmosomal junction alterations is associated with increased severity of gastroesophageal reflux disease. Besides dilated intercellular space, subtle changes in ultrastructural morphology of intercellular space allow better identification of inflamed esophageal mucosa relevant to acid reflux.
Biopsy ; Claudin-2 ; Epithelium ; Esophagogastric Junction ; Esophagus ; Extracellular Space ; Gastroesophageal Reflux ; Humans ; Immunohistochemistry ; Intercellular Junctions ; Microscopy, Electron, Transmission ; Mucous Membrane ; Tight Junction Proteins ; Tight Junctions

OBJECTIVE: To study the expression and significance of tight junction proteins (claudin-2, claudin-10, and claudin-17) in a mouse model of renal ischemia-reperfusion injury. METHODS: A total of 152 male C57BL/6 mice were randomly assigned to control group (n=8), sham-operation group (n=72), and model group (n=72). The renal pedicles at both sides were clamped for 30 minutes to establish a mouse model of renal ischemia-reperfusion injury. According to the time points of reperfusion (0, 3, 6, 12, 24, 48, and 72 hours and 5 and 7 days), the sham-operation group and the model group were further divided into 9 subgroups, with 8 mice in each subgroup. RT-PCR and immunohistochemistry were used to measure the mRNA and protein expression of claudin-2, claudin-10, and claudin-17 in renal tissue. RESULTS: The control and sham-operation groups had no significant changes in the mRNA and protein expression of claudin-2, claudin-10, and claudin-17 in renal tissue over the time of reperfusion (P>0.05). Compared with the control and sham-operation groups, the model group had decreased mRNA and protein expression of claudin-2 and claudin-10 after reperfusion, and the expression decreased gradually over the time of reperfusion, with the lowest levels at 24 hours of reperfusion (P<0.05). Compared with the control and sham-operation groups, the model group had increased mRNA and protein expression of claudin-17 after reperfusion, and the expression increased gradually over the time of reperfusion, with the highest mRNA level at 12 hours and the highest protein level at 24 hours of reperfusion (P<0.05). CONCLUSIONS Renal ischemia-reperfusion injury is closely associated with abnormal expression of tight junction proteins claudin-2, claudin-10, and claudin-17.
Animals ; Kidney ; Male ; Mice ; Mice, Inbred C57BL ; Rats, Sprague-Dawley ; Reperfusion Injury ; Tight Junction Proteins

PURPOSE: Tight junction proteins are either over-expressed or suppressed in some cancers. These suppressions of claudin-1 and ZO-1 protein are known to have a significant relationship with the progression of breast cancer. The authors reviewed 42 cases of breast cancer and the staining status of claudin-1 and ZO-1 in order to evaluate Claudin-1 and ZO-1 as clinicopathologic risk factors. METHODS: Immunohistological staining for Claudin-1 and ZO-1 was performed in 42 post-operative pathologically diagnosed infiltrating duct carcinoma specimens. The rate of expression was compared with the clinical record, the pathological diagnosis, the estrogen receptor and progesteron receptor status and the c-erbB2 gene to evaluate the protein expression-breast cancer progression relationship and to investigate the expressions of Claudin-1 and ZO-1 as a prognostic factors in breast cancer. RESULTS: The claudin-1 and ZO-1 expressions were both decreased in all the post-operative specimens. The claudin-1 expressions were significantly decreased 100%, 82.4% and 66.7% as the histologic grade increased. The ZO-1 expressions were shown in 44.8% of the lymph node metastasis negative group and in 7.7% of the lymph node positive group. The expression of ZO-1 decreased by 53.3%, 28.6% and 0%, with statistical significance, as the stage increased. CONCLUSION: The claudin-1 expressions were decreased in the poorly differentiated group, i.e., a high histologic grade, and the ZO-1 expressions were decreased in the lymph node positive group and in the high stage cancer. This shows the possibility of Claudin-1 and ZO-1 as factors for tumorigenesis and progression and as prognostic factors in breast cancer.
Breast Neoplasms* ; Breast* ; Carcinogenesis ; Claudin-1* ; Diagnosis ; Estrogens ; Lymph Nodes ; Neoplasm Metastasis ; Risk Factors ; Staphylococcal Protein A* ; Tight Junction Proteins ; Tight Junctions

BACKGROUND/AIMS: The aim of this study was to investigate the effects of rebamipide on tight junction proteins in the esophageal mucosa in a rat model of gastroesophageal reflux disease (GERD). METHODS: GERD was created in rats by tying the proximal stomach. The rats were divided into a control group, a proton pump inhibitor (PPI) group, and a PPI plus rebamipide (PPI+R) group. Pantoprazole (5 mg/kg) was administered intraperitoneally to the PPI and PPI+R groups. An additional dose of rebamipide (100 mg/kg) was administered orally to the PPI+R group. Mucosal erosions, epithelial thickness, and leukocyte infiltration into the esophageal mucosa were measured in isolated esophagi 14 days after the procedure. A Western blot analysis was conducted to measure the expression of claudin-1, -3, and -4. RESULTS: The mean surface area of mucosal erosions, epithelial thickness, and leukocyte infiltration were lower in the PPI group and the PPI+R group than in the control group. Western blot analysis revealed that the expression of claudin-3 and -4 was significantly higher in the PPI+R group than in the control group. CONCLUSIONS: Rebamipide may exert an additive effect in combination with PPI to modify the tight junction proteins of the esophageal mucosa in a rat model of GERD. This treatment might be associated with the relief of GERD symptoms.
Animals ; Blotting, Western ; Claudin-1 ; Claudin-3 ; Gastroesophageal Reflux ; Leukocytes ; Models, Animal ; Mucous Membrane ; Proton Pump Inhibitors ; Proton Pumps ; Protons ; Rats ; Stomach ; Tight Junction Proteins ; Tight Junctions

BACKGROUND/AIMS: Male predominance has been observed in the erosive reflux disease (ERD), but reverse finding in nonerosive reflux disease (NERD). This suggests sex-specific medicine approach is needed but its mechanism is remained to be elucidated. We aimed to compare clinical characteristics and mRNA expression levels of tight junction-related proteins between male and female gastroesophageal reflux disease (GERD). METHODS: Sixteen healthy controls, 45 ERD, and 14 NERD patients received upper endoscopies and completed questionnaires. Quantitative real-time polymerase chain reactions of occludin (OCLN), zonal occludens (ZO) 1, claudin-1 (CLDN1) and claudin-4 (CLDN4), and neurokinin 1 receptor (NK1R) were performed in the distal esophageal mucosal specimen. These results were analyzed by sex. RESULTS: Female GERD patients were affected more by reflux symptoms than males. The impairment of overall quality of life was more prominent in female patients with reflux symptoms than male patients (5.6±0.2 vs 4.9±0.6, p=0.009). The levels of OCLN mRNA expression were significantly lower in the male ERD group. On the other hand, those of CLDN1, CLDN4, and NK1R except ZO-1 were significantly higher in the male ERD group. CONCLUSIONS: We demonstrated that female ERD/NERD patients were affected more by GERD and male ERD patients showed significant changes of tight junction protein mRNA expression levels.
Claudin-1 ; Claudin-4 ; Female* ; Fluconazole ; Gastroesophageal Reflux* ; Hand ; Humans ; Male* ; Occludin ; Polymerase Chain Reaction ; Quality of Life ; Receptors, Neurokinin-1 ; RNA, Messenger* ; Tight Junction Proteins ; Tight Junctions*

PURPOSE: Peritumoral brain edema (PTBE) is a serious causative factor that contributes the morbidity or mortality of brain tumors. The development of PTBE is influenced by many factors, including such tight junction proteins as occludin. We evaluated the PTBE volume and survival time with respect to the occludin expression in various pathological types of brain tumors. MATERIALS AND METHODS: Fresh-frozen specimens from sixty patients who had brain tumors were obtained during surgery and the tumors were confirmed pathologically. The occludin expression was investigated by Western blot analysis. The PTBE volume was measured by using preoperative magnetic resonance (MR) imaging, and the survival time in each patient was estimated retrospectively. RESULTS: Occludin was detected in 41 (68.3%) of the cases with brain tumors and it was not expressed in the other 19 (31.7%) cases. Although the lowest expression was revealed in high-grade gliomas, its expression was variable according to the pathology of the brain tumors (p>0.05). The difference of PTBE volume between occludin-positive and negative brain tumors was statistically significant (2072.46+/-328.73 mm3 vs. 7452.42+/-1504.19 mm3, respectively, p=0.002). The mean survival time was longer in the occludin-positive tumor group than in the occludin-negative group (38.63+/-1.57 months vs. 26.16+/-3.83 months, respectively; p=0.016). CONCLUSIONS: This study suggests that the occludin expression is highly correlated to the development of PTBE in brain tumors and it might be a prognostic indicator for patient survival.
Blotting, Western ; Brain Edema ; Brain Neoplasms* ; Brain* ; Edema* ; Glioma ; Humans ; Mortality ; Occludin* ; Pathology ; Retrospective Studies ; Survival Rate ; Tight Junction Proteins

OBJECTIVE: To investigate the mechanism by which fibroblasts with high WNT2b expression causes intestinal mucosa barrier disruption and promote the progression of inflammatory bowel disease (IBD). METHODS: Caco-2 cells were treated with 20% fibroblast conditioned medium or co-cultured with fibroblasts highly expressing WNT2b, with the cells without treatment with the conditioned medium and cells co-cultured with wild-type fibroblasts as the control groups. The changes in barrier permeability of Caco-2 cells were assessed by measuring transmembrane resistance and Lucifer Yellow permeability. In Caco-2 cells co-cultured with WNT2b-overexpressing or control intestinal fibroblasts, nuclear entry of β-catenin was detected with immunofluorescence assay, and the expressions of tight junction proteins ZO-1 and E-cadherin were detected with Western blotting. In a C57 mouse model of dextran sulfate sodium (DSS)-induced IBD-like enteritis, the therapeutic effect of intraperitoneal injection of salinomycin (5 mg/kg, an inhibitor of WNT/β-catenin signaling pathway) was evaluated by observing the changes in intestinal inflammation and detecting the expressions of tight junction proteins. RESULTS: In the coculture system, WNT2b overexpression in the fibroblasts significantly promoted nuclear entry of β-catenin (P < 0.01) and decreased the expressions of tight junction proteins in Caco-2 cells; knockdown of FZD4 expression in Caco-2 cells obviously reversed this effect. In DSS-treated mice, salinomycin treatment significantly reduced intestinal inflammation and increased the expressions of tight junction proteins in the intestinal mucosa. CONCLUSION Intestinal fibroblasts overexpressing WNT2b causes impairment of intestinal mucosal barrier function and can be a potential target for treatment of IBD.
Humans ; Mice ; Animals ; Caco-2 Cells ; beta Catenin/metabolism* ; Culture Media, Conditioned/pharmacology* ; Tight Junctions/metabolism* ; Intestinal Mucosa ; Inflammatory Bowel Diseases ; Tight Junction Proteins/metabolism* ; Inflammation/metabolism* ; Fibroblasts/metabolism* ; Mice, Inbred C57BL ; Glycoproteins/metabolism* ; Wnt Proteins/pharmacology* ; Frizzled Receptors/metabolism*

BACKGROUND/AIMS: Duodenal immune alterations have been reported in a subset of patients with functional dyspepsia (FD). The aim of this study was to investigate the effect of acute stress on immune cell counts and the expression of tight junction proteins in the duodenal mucosa. METHODS: Twenty-one male rats were divided into the following three experimental groups: 1) the nonstressed, control group, 2) the 2-hour-stressed group, and 3) the 4-hour-stressed group. Eosinophils, mast cells and CD4+ and CD8+ T lymphocytes in the duodenal mucosa were counted. The protein and mRNA expressions of occludin and zonula occludens-1 (ZO-1) were examined. RESULTS: Eosinophils, mast cells and CD8+ T lymphocyte counts did not differ between the stressed and control groups. The number of CD4+ T lymphocytes and the protein and mRNA expressions of occludin and ZO-1 were significantly lower in the 4-hour-stressed group compared with the control group. The plasma adrenocorticotrophic hormone and cortisol levels of the 4-hour-stressed group were significantly higher than those of the control group. CONCLUSIONS: Acute stress reduces the number of CD4+ T lymphocytes and the expression of tight junction proteins in the duodenal mucosa, which might be associated with the duodenal immune alterations found in a subset of FD patients.
Adrenocorticotropic Hormone ; Animals ; Cell Count ; Duodenum ; Dyspepsia ; Eosinophils ; Humans ; Hydrocortisone ; Lymphocyte Count ; Lymphocytes ; Male ; Mast Cells ; Mucous Membrane ; Occludin ; Plasma ; Rats ; RNA, Messenger ; T-Lymphocytes ; Tight Junction Proteins ; Tight Junctions