ABSTRACT
Objective: To investigate the effect of nuclear factor erythroid 2-related factor 2 (Nrf2) in the alteration of tight junction protein expression in choroid plexus epithelial cells created by lanthanum-activated matrix metalloproteinase 9 (MMP9) . Methods: In October 2020, immortalized rat choroid plexus epithelial cell line (Z310) cells were used as the blood-cerebrospinal fluid barrier in vitro, and were divided into control group and 0.125, 0.25, 0.5 mmol/L lanthanum chloride (LaCl(3)) treatment group. After treating Z310 cells with different concentrations of LaCl(3) for 24 hours, the morphological changes of Z310 cells were observed under inverted microscope, the protein expression levels of MMP9, occludin and zonula occludens-1 (ZO-1) were observed by cellular immunofluorescence method, and the protein expression levels of MMP9, tissue inhibitors of metalloproteinase1 (TIMP1) , occludin, ZO-1 and Nrf2 were detected by Western blotting. The level of reactive oxygen species (ROS) in cells was detected by flow cytometry. Results: Compared with the control group, Z310 cells in the LaCl(3) treatment group were smaller in size, with fewer intercellular junctions, and more dead cells and cell fragments. The expression level of MMP9 protein in cells treated with 0.25 and 0.5 mmol/L LaCl(3) was significantly higher than that in the control group (P<0.05) , and the expression level of TIMP1 and tight junction proteins occudin and ZO-1 was significantly lower than that in the control group (P<0.05) . Compared with the control group, the ROS production level in the 0.25, 0.5 mmol/L LaCl(3) treatment group was significantly increased (P<0.05) , and the Nrf2 protein expression level in the 0.125, 0.25, 0.5 mmol/L LaCl(3) treatment group was significantly decreased (P<0.05) . Conclusion: Lanthanum may increase the level of ROS in cells by down regulating the expression of Nrf2, thus activating MMP9 to reduce the expression level of intercellular tight junction proteins occludin and ZO-1.
Subject(s)
Rats , Animals , Matrix Metalloproteinase 9/metabolism , NF-E2-Related Factor 2/metabolism , Tight Junction Proteins/metabolism , Occludin/pharmacology , Choroid Plexus/metabolism , Reactive Oxygen Species/metabolism , Lanthanum/pharmacology , Epithelial Cells , Zonula Occludens-1 Protein/metabolism , Phosphoproteins/pharmacologyABSTRACT
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.
Subject(s)
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/metabolismABSTRACT
The aim of this paper was to explore the effect and mechanism of Jiawei Baitouweng Decoction(JWBTW) against ulcerative colitis(UC) from the perspective of intestinal mucosal tight junction proteins. From 60 SPF-grade male SD rats, 10 were randomly selected as the blank control, and the remaining 50 were treated with 3% dextran sodium sulfate(DSS) solution to induce UC and then randomized into the model group, mesalazine group, and low-, medium-, and high-dose JWBTW( L-JWBTW, M-JWBTW and H-JWBTW) groups, with 10 rats in each group. After successive medication for 14 days, the rat general conditions like body weight and stool were observed and the disease activity index(DAI) was calculated. The pathological changes in colon tissue was observed under a microscope for injury severity scoring and histopathological scoring. The serum endotoxin content was determined by limulus assay, followed by the measurement of protein expression levels of ZO-1, occludin, claudin-1, p38 MAPK, MLCK, MLC2 and p-MLC in colon tissue by Western blot. The results showed that compared with the blank group, the model group exhibited significantly reduced body weight, elevated DAI, injury severity and histopathological scores and serum endotoxin content, up-regulated protein expression levels of p38 MAPK, MLCK, MLC2 and p-MLC, and down-regulated ZO-1, occludin and claudin-1. Compared with the model group,mesalazine and JWBTW at each dose obviously increased the body weight, lowered the DAI, injury severity and histopathological scores and serum endotoxin content, down-regulated the protein expression levels of p38 MAPK, MLCK, MLC2 and p-MLC, and up-regulated the ZO-1, occludin and claudin-1, with the most obvious changes noticed in the H-JWBTW group. All these have indicated that JWBTW exerts the therapeutic effect against UC by inhibiting the activation of p38 MAPK/MLCK pathway, reversing the protein expression levels of occludin, claudin-1 and ZO-1, decreasing the serum endotoxin content, promoting the repair of intestinal mucosal mechanical barrier, maintaining the integrity of tight junctions, and reducing the permeability of intestinal mucosa.
Subject(s)
Animals , Male , Rats , Colitis, Ulcerative/genetics , Disease Models, Animal , Intestinal Mucosa , Rats, Sprague-Dawley , Signal Transduction , Tight Junction Proteins/genetics , p38 Mitogen-Activated Protein Kinases/geneticsABSTRACT
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.
Subject(s)
Humans , Cell Line , Epithelial Cells , ErbB Receptors , Mucin 5AC , Respiratory Syncytial Virus Infections , Tight Junction Proteins , Tight JunctionsABSTRACT
PURPOSE: Cockroach exposure is a pivotal cause of asthma. Tight junctions are intercellular structures required for maintenance of the barrier function of the airway epithelium, which is impaired in this disease. Matrix metalloproteinases (MMPs) digest extracellular matrix components and are involved in asthma pathogenesis: MMP1 is a collagenase with a direct influence on airway obstruction in asthmatics. This study aimed to investigate the mechanism by which German cockroach extract (GCE) induces MMP1 expression and whether MMP1 release alters cellular tight junctions in human airway epithelial cells (NCI-H292). MATERIALS AND METHODS: mRNA and protein levels were determined using real-time PCR and ELISA. Tight junction proteins were detected using immunofluorescence staining. Epithelial barrier function was measured by transepithelial electrical resistance (TEER). The binding of a transcription factor to DNA molecules was determined by electrophoretic mobility shift assay, while the levels of tight junction proteins and phosphorylation were determined using Western blotting. RESULTS: GCE was shown to increase MMP1 expression, TEER, and tight junction degradation. Both an inhibitor and small interfering RNA (siRNA) of MMP1 significantly decreased GCE-induced tight junction disruption. Furthermore, transient transfection with ETS1 and SP1 siRNA, and anti-TLR2 antibody pretreatment prevented MMP1 expression and tight junction degradation. An extracellular signal-regulated kinase (ERK)/mitogen-activated protein kinase (MAPK) inhibitor also blocked MMP1 release, ETS1/SP1 DNA binding, and tight junction alteration. CONCLUSION: GCE treatment increases MMP1 expression, leading to tight junction disruption, which is transcriptionally regulated and influenced by the ERK/MAPK pathway in airway epithelial cells. These findings may contribute to developing novel therapeutic strategies for airway diseases.
Subject(s)
Humans , Airway Obstruction , Asthma , Blattellidae , Blotting, Western , Cockroaches , Collagenases , DNA , Electric Impedance , Electrophoretic Mobility Shift Assay , Enzyme-Linked Immunosorbent Assay , Epithelial Cells , Epithelium , Extracellular Matrix , Fluorescent Antibody Technique , Matrix Metalloproteinase 1 , Matrix Metalloproteinases , Phosphorylation , Phosphotransferases , Protein Kinases , Real-Time Polymerase Chain Reaction , RNA, Messenger , RNA, Small Interfering , Tight Junction Proteins , Tight Junctions , Transcription Factors , TransfectionABSTRACT
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.
Subject(s)
Animals , Male , Mice , Kidney , Mice, Inbred C57BL , Rats, Sprague-Dawley , Reperfusion Injury , Tight Junction ProteinsABSTRACT
Tight junctions (TJs) are the most apical intercellular junctions of epithelial cells formed by occludin, claudins, junctional adhesion molecules (JAMs), and zonula occludens (ZO). Tight junction proteins can sense the presence of bacteria and regulate the transcription of target genes that encode effectors and regulators of the immune response. The aim of this study was to determine the impact of TJ proteins in response to Porphyromonas gingivalis (P. gingivalis), P. gingivalis lipopolysaccharide (P. gingivalis LPS), and extracellular adenosine triphosphate (ATP) in the oral epithelial cell culture model. Quantified real time-polymerase chain reaction (RT-PCR), immunoblots, and immunostaining were performed to assess the gene and protein expression in TJs. It was found that P. gingivalis infection led to transient upregulation of the genes encoding occludin, claudin-1, and claudin-4 but not JAM-A, claudin-15, or ZO-1, while P. gingivalis LPS increased claudin-1, claudin-15, and ZO-1 and decreased occludin, JAM-A, and claudin-4. Tight junction proteins showed significant upregulation in the above two groups when cells were pretreated with ATP for 3 h. The findings indicated that P. gingivalis induced the host defence responses at an early stage. P. gingivalis LPS exerted a more powerful stimulatory effect on the disruption of the epithelial barrier than P. gingivalis. ATP stimulation enhanced the reaction of TJ proteins to P. gingivalis invasion and LPS destruction of the epithelium.International Journal of Oral Science (2018) 10, e8; doi:10.1038/ijos.2017.51; published online 10 January 2018.
Subject(s)
Humans , Adenosine Triphosphate , Pharmacology , Cells, Cultured , Epithelial Cells , Cell Biology , Gene Expression , Immunoblotting , Lipopolysaccharides , Pharmacology , Mouth Mucosa , Cell Biology , Porphyromonas gingivalis , Allergy and Immunology , Real-Time Polymerase Chain Reaction , Tight Junction Proteins , Metabolism , Up-RegulationABSTRACT
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.
Subject(s)
Animals , Rats , Blotting, Western , Claudin-1 , Claudin-3 , Gastroesophageal Reflux , Leukocytes , Models, Animal , Mucous Membrane , Proton Pump Inhibitors , Proton Pumps , Protons , Stomach , Tight Junction Proteins , Tight JunctionsABSTRACT
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.
Subject(s)
Female , Humans , Male , Claudin-1 , Claudin-4 , Fluconazole , Gastroesophageal Reflux , Hand , Occludin , Polymerase Chain Reaction , Quality of Life , Receptors, Neurokinin-1 , RNA, Messenger , Tight Junction Proteins , Tight JunctionsABSTRACT
Objective@#To explore the role of TGF-β1 in the proliferation and apoptosis of Sertoli cells and its effect on the expressions of tight junction-related proteins and genes in rats.@*METHODS@#Rat Sertoli cells were isolated in vitro, primarily cultured, and divided into groups A (blank control), B (TGF-β1 receptor blocker), C (TGF-β1), and D (TGF-β1 + receptor blocker). The proliferation and apoptosis of the cells were detected by CCK-8 and flow cytometry, respectively. After establishment of the dual-chamber model for the primary culture of Sertoli cells, the trans-epithelia electrical resistance (TER) value was measured and the relative expressions of Occludin, ZO-1 and Claudin Ⅱ determined by RT-PCR and Western blot.@*RESULTS@#The OD value of the proliferation of the Sertoli cells was markedly higher in group C than in groups A and D (0.79 ± 0.04 vs 0.66 ± 0.05 and 0.68 ± 0.02, P0.05). The TER value was dramatically decreased in group C as compared with groups A and D ([176.37 ± 16.61] vs [281.42 ± 9.83] and [254.37 ± 13.55] /cm2, P0.05) or their protein expressions (F = 0.28 and 1.31, P>0.05). Both the mRNA and protein expressions of Occludin were markedly lower in group C than in A and D (P<0.01 and P<0.05), with statistically significant differences among the four groups (F = 6.86 and 6.87, P<0.01).@*CONCLUSIONS@#TGF-β1 can promote the proliferation of Sertoli cells in rats and act on the tight junction of the cells by regulating the expression of Occludin.
Subject(s)
Animals , Male , Rats , Apoptosis , Cell Proliferation , Cells, Cultured , Claudin-2 , Metabolism , Occludin , Metabolism , RNA, Messenger , Sertoli Cells , Cell Biology , Physiology , Tight Junction Proteins , Metabolism , Tight Junctions , Genetics , Metabolism , Transforming Growth Factor beta1 , Physiology , Zonula Occludens-1 Protein , MetabolismABSTRACT
Inflammatory bowel disease is a chronic inflammatory disorder occurring in the gastrointestinal track. However, the efficacy of current therapeutic strategies has been limited and accompanied by side effects. In order to eliminate the limitations, herbal medicines have recently been developed for treatment of IBD. Peuraria Lobata (Peuraria L.) is one of the traditional herbal medicines that have anti-inflammatory effects. Bioavailability of Peuraria L., which is rich in isoflavones, is lower than that of their fermented forms. In this study, we generated fermented Peuraria L. extracts (fPue) and investigated the role of fPue in inflammation and intestinal barrier function in vitro and in vivo. As the mice or intestinal epithelial cells were treated with DSS/fPue, mRNA expression of pro-inflammatory cytokines was reduced and the architecture and expression of tight junction proteins were recovered, compared to the DSS-treated group. In summary, fPue treatment resulted in amelioration of DSS-induced inflammation in the colon, and the disrupted intestinal barrier was recovered as the expression and architecture of tight junction proteins were retrieved. These results suggest that use of fPue could be a new therapeutic strategy for treatment of IBD.
Subject(s)
Animals , Mice , Biological Availability , Colitis , Colon , Cytokines , Dextran Sulfate , Dextrans , Epithelial Cells , In Vitro Techniques , Inflammation , Inflammatory Bowel Diseases , Isoflavones , Pueraria , RNA, Messenger , Tight Junction ProteinsABSTRACT
<p><b>OBJECTIVE</b>To understand the junction protein expression of gastric mucosa including occlusal proteins (occludin), closed protein-4 (claudin-4), zonula occluden-1(ZO-1), epithelial cadherin (E-cadherin), and β ring protein (β-catenin) and the clinical significance in children with Helicobacter pylori (Hp) infection.</p><p><b>METHOD</b>Seventy patients in whom gastric endoscopy was performed because of nausea, vomiting, abdominal pain, bloating, acid reflux, melena, and other gastrointestinal symptoms were enrolled in this study from Dec. 2010 to Apr. 2013 in our hospital. Informed consent was signed by their parents, and the study was in accordance with the principles of medical ethics. Hp positivity was confirmed if both respiratory urea test (RUT) and Hp were positive by gastric mucosal pathology. Gastric mucosal samples from 70 patients were enrolled in this study, 23 of them were Hp negative, 47 of them were Hp positive (24 cases without peptic ulcer, 23 cases with peptic ulcer). The mRNA levels and protein expression of tight junction protein of gastric mucosa were measured by RT-PCR and Western blot respectively. The location and semi quantitative content of E-cadherin and β-catenin in gastric mucosa were detected by immunohistochemical staining method.</p><p><b>RESULT</b>The mRNA level of E-cadherin, β-catenin, ZO-1 in the Hp positive group regardless of peptic ulcer was significantly lower than that in the Hp negative group. Hp positive without peptic ulcer group were 0.0008, 0.0040, 0.0014, respectively; Hp positive with peptic ulcer group were 0.0010, 0.0090, 0.0013, respectively; Hp negative group were 0.0137, 0.0423, 0.0198, respectively (F values were 36.956, 39.893, 38.962, respectively, all P<0.05). The expression of claudin-4 mRNA in Hp positive group with peptic ulcer increased significantly, the difference among Hp positive group with peptic ulcer, Hp positive group without peptic ulcer and Hp negative group was statistically significant (0.1438 vs. 0.0926 vs. 0.0789) (F value was 11.964, P<0.05), while the difference of occludin mRNA levels among the three groups was not statistically significant.Immunohistochemistry results showed that the score of E-cadherin, β-catenin positive cell in the Hp positive patients were also significantly lower than that in the Hp negative group (t values were 3.981 and 2.340, all P<0.05, respectively). Western blot results showed that the protein levels of β-catenin in Hp positive group with peptic ulcer were significantly lower than that in Hp negative group, while the protein levels of E-cadherin in Hp positive patients regardless of peptic ulcer were decreased significantly in Hp negative group.</p><p><b>CONCLUSION</b>Our results revealed that the tight junction protein E-cadherin, β-catenin, ZO-1 expression of gastric mucosa were decreased in children with Hp infection, while claudin-4 expression was increased in Hp positive patients with peptic ulcer, suggesting that damage to gastric epithelial barrier function may be the main pathogenesis of Hp associated gastric diseases in children.</p>
Subject(s)
Child , Humans , Blotting, Western , Cadherins , Metabolism , Claudin-4 , Metabolism , Gastric Mucosa , Metabolism , Pathology , Helicobacter Infections , Metabolism , Helicobacter pylori , Immunohistochemistry , Occludin , Metabolism , Peptic Ulcer , Metabolism , Microbiology , RNA, Messenger , Tight Junction Proteins , Metabolism , Tight Junctions , Metabolism , Zonula Occludens-1 Protein , Metabolism , beta Catenin , MetabolismABSTRACT
<p><b>OBJECTIVE</b>To investigate the effects of the combination of musk and olibanum on the tight junction protein expressions in prostatic epithelial cells of normal and chronic prostatitis (CP) rats.</p><p><b>METHODS</b>Eighty male SD rats were randomly divided into 8 groups of equal number: normal control, normal musk, normal olibanum, normal musk + olibanum, CP model control, CP model musk, CP model olibanum, and CP model musk + olibanum. At 60 days after modeling, the rats in the control, musk, olibanum, and musk + olibanum groups were treated intragastrically with normal saline, musk (0.021 g per kg body weight per day), olibanum (1.05 g per kg body weight per day), or musk + olibanum respectively, all for 3 days. Then, all the rats were sacrificed and their prostate tissues harvested for detection of the expressions of the tight junction proteins Claudin-1, Claudin-3, Occludin, and ZO-1 in the prostatic epithelial cells by immunohistochemical staining.</p><p><b>RESULTS</b>In the CP models, only the expression of Claudin-1 was significantly increased. In the normal rats, the expression of Claudin-1 was remarkably upregulated after treated with musk (824.6 ± 393.3, P < 0.05), olibanum (982.0 ± 334.0, P < 0.05), and musk + olibanum (1088.1 ± 640.2, P < 0.01); that of Claudin-3 was elevated markedly by olibanum (1 009.5 ± 243.6, P < 0.05) and insignificantly by musk (597.5 ± 80.7), but the increasing effect of olibanum was reduced by musk + olibanum (678.4 ± 255.1). No statistically significant differences were found in the expression of Occludin among the rats treated with musk (693.0 ± 424.8), olibanum (732.1 ± 302.0), and musk + olibanum (560.2 ± 202.3), or in that of ZO-1 in the animals treated with musk (290.0 ± 166.8) and olibanum (419.7 ± 108.1), but the latter was markedly decreased in the musk + olibanum group (197.7 ± 98.2, P < 0.05). In the CP rat models, both the expressions of Claudin-1 (823.0 ± 100.1, P < 0.01) and Occludin (1160.0 ± 32.2, P < 0.05) were significantly increased. The expression of Claudin-1 was remarkably down-regulated by musk (764.9 ± 179.0), olibanum (468.4 ± 220.4), and musk + olibanum (335.1 ± 204.0) (all P < 0.05), but that of Claudin-3 up-regulated by musk (744.6 ± 94.5) and olibanum (700.1 ± 223.7) (both P < 0.05). The expression of Occludin was reduced by musk (615.0 ± 221.0), olibanum (749.6 ± 321.7), and musk + olibanum (505.8 ± 523.7), while that of ZO-1 increased by olibaum (443.2 ± 44.9) and decreased by musk + olibanum (213.5 ± 24.9, P < 0.05).</p><p><b>CONCLUSION</b>In physiological and pathological conditions, the combination of musk and olibanum acts on the expressions of tight junction proteins in prostate epithelial cells in a selective and dual-targeting manner, promoting their permeability by down-regulating the expression of ZO-1 and maintaining their structural stability by regulating the expressions of Claudin-1, Claudin-3, and Occludin.</p>
Subject(s)
Animals , Male , Rats , Claudins , Metabolism , Down-Regulation , Epithelial Cells , Fatty Acids, Monounsaturated , Chemistry , Frankincense , Chemistry , Occludin , Metabolism , Prostate , Cell Biology , Prostatitis , Rats, Sprague-Dawley , Tight Junction Proteins , Metabolism , Up-RegulationABSTRACT
Our previous study has shown berberine prevents damage to the intestinal mucosal barrier during early phase of sepsis in rat through mechanisms independent of the NOD-like receptors signaling pathway. In this study, we explored the regulatory effects of berberine on Toll-like receptors during the intestinal mucosal damaging process in rats. Male Sprague-Dawlay (SD) rats were treated with berberine for 5 d before undergoing cecal ligation and puncture (CLP) to induce polymicrobial sepsis. The expression of Toll-like receptor 2 (TLR 2), TLR 4, TLR 9, the activity of nuclear factor-kappa B (NF-kappaB), the levels of selected cytokines and chemokines, percentage of cell death in intestinal epithelial cells, and mucosal permeability were investigated at 0, 2, 6, 12 and 24 h after CLP. Results showed that the tumor necrosis factor-alpha (TNF-alpha ) and interleukin-6 (IL-6) level were significantly lower in berberine-treated rats compared to the control animals. Conversely, the expression level of tight junction proteins, percentage of cell death in intestinal epithelial cells and the mucosal permeability were significantly higher in berberine-treated rats. The mRNA expression of TLR 2, TLR 4, and TLR 9 were significantly affected by berberine treatment. Our results indicate that pretreatment with berberine attenuates tissue injury and protects the intestinal mucosal barrier in early phase of sepsis and this may possibly have been mediated through the TLRs pathway.
Subject(s)
Animals , Humans , Male , Rats , Berberine , Cell Death , Chemokines , Cytokines , Epithelial Cells , Interleukin-6 , Intraabdominal Infections , Ligation , Permeability , Punctures , RNA, Messenger , Sepsis , Tight Junction Proteins , Toll-Like Receptor 2 , Toll-Like Receptors , Tumor Necrosis Factor-alphaABSTRACT
Glutathione (GSH) protects cells against oxidative stress by playing an antioxidant role. Protecting brain endothelial cells under oxidative stress is key to treating cerebrovascular diseases and neurodegenerative diseases including Alzheimer's disease and Huntington's disease. In present study, we investigated the protective effect of GSH on brain endothelial cells against hydrogen peroxide (H2O2). We showed that GSH attenuates H2O2-induced production of nitric oxide (NO), reactive oxygen species (ROS), and 8-Oxo-2'-deoxyguanosine (8-OHdG), an oxidized form of deoxiguanosine. GSH also prevents H2O2-induced reduction of tight junction proteins. Finally, GSH increases the level of nuclear factor erythroid 2-related factor 2 (Nrf2) and activates Nrf2-mediated signaling pathways. Thus, GSH is a promising target to protect brain endothelial cells in conditions of brain injury and disease.
Subject(s)
Alzheimer Disease , Apoptosis , Brain Injuries , Brain , Endothelial Cells , Glutathione , Huntington Disease , Hydrogen Peroxide , Hydrogen , Neurodegenerative Diseases , Nitric Oxide , Oxidative Stress , Reactive Oxygen Species , Tight Junction ProteinsABSTRACT
Helicobacter pylori (Hp) infection is an important cause of chronic gastritis and peptic ulcer, but their pathogenesis is unclear. The role of gastric mucosal barrier dysfunction induced by impaired structure and function of tight junction in the pathogenesis of Hp-associated gastric diseases has received considerable attention in recent years. Tight junction is composed of a variety of proteins and molecules, including 3 integral membrane proteins (occludin, claudins, and junctional adhesion molecules) and a cytoplasmic protein (zonula occludens). This paper mainly describes the composition and function of various tight junction proteins, changes in tight junction protein function induced by Hp infection and their relationship with the incidence of gastric diseases, and the significance of enhancing the tight junction protein function in the prevention and treatment of Hp-associated gastric diseases.
Subject(s)
Humans , Helicobacter Infections , Helicobacter pylori , Virulence , Oxidative Stress , Stomach Diseases , Stomach Neoplasms , Tight Junction Proteins , Chemistry , PhysiologyABSTRACT
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.
Subject(s)
Humans , Biopsy , Claudin-2 , Epithelium , Esophagogastric Junction , Esophagus , Extracellular Space , Gastroesophageal Reflux , Immunohistochemistry , Intercellular Junctions , Microscopy, Electron, Transmission , Mucous Membrane , Tight Junction Proteins , Tight JunctionsABSTRACT
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.
Subject(s)
Animals , Humans , Male , Rats , Adrenocorticotropic Hormone , Cell Count , Duodenum , Dyspepsia , Eosinophils , Hydrocortisone , Lymphocyte Count , Lymphocytes , Mast Cells , Mucous Membrane , Occludin , Plasma , RNA, Messenger , T-Lymphocytes , Tight Junction Proteins , Tight JunctionsABSTRACT
To evaluate the effect of chlorogenic acid (CGA), a polyphenol abundant in coffee, on retinal vascular leakage in the rat model of diabetic retinopathy, Sprague-Dawley rats were divided into four groups: controls, streptozotocin-induced diabetic rats, and diabetic rats treated with 10 and 20 mg/kg chlorogenic acid intraperitoneally daily for 14 days, respectively. Blood-retinal barrier (BRB) breakdown was evaluated using FITC-dextran. Vascular endothelial growth factor (VEGF) distribution and expression level was evaluated with immunohistochemistry and Western blot analysis. Expression of tight junction proteins, occludin and claudin-5, and zonula occludens protein, ZO-1 was also evaluated with immunohistochemistry and Western blot analysis. BRB breakdown and increased vascular leakage was found in diabetic rats, with increased VEGF expression and down-regulation of occludin, claudin-5, and ZO-1. CGA treatment effectively preserved the expression of occludin, and decreased VEGF levels, leading to less BRB breakdown and less vascular leakage. CGA may have a preventive role in BRB breakdown in diabetic retinopathy by preserving tight junction protein levels and low VEGF levels.
Subject(s)
Animals , Male , Rats , Blood-Retinal Barrier/drug effects , Chlorogenic Acid/metabolism , Claudin-5/metabolism , Dextrans/chemistry , Diabetes Mellitus, Experimental/complications , Diabetic Retinopathy/etiology , Down-Regulation , Fluorescein-5-isothiocyanate/chemistry , Occludin/metabolism , Rats, Sprague-Dawley , Retina/metabolism , Tight Junction Proteins/metabolism , Vascular Endothelial Growth Factor A/metabolism , Zonula Occludens-1 Protein/metabolismABSTRACT
No abstract available.