OBJECTIVE: To investigate the effects of Danmu Extract Syrup (DMS) on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in mice and explore the mechanism. METHODS: Seventy-two male Balb/C mice were randomly divided into 6 groups according to a random number table (n=12), including control (normal saline), LPS (5 mg/kg), LPS+DMS 2.5 mL/kg, LPS+DMS 5 mL/kg, LPS+DMS 10 mL/kg, and LPS+Dexamethasone (DXM, 5 mg/kg) groups. After pretreatment with DMS and DXM, the ALI mice model was induced by LPS, and the bronchoalveolar lavage fluid (BALF) were collected to determine protein concentration, cell counts and inflammatory cytokines. The lung tissues of mice were stained with hematoxylin-eosin, and the wet/dry weight ratio (W/D) of lung tissue was calculated. The levels of tumor necrosis factor-α (TNF-α), interleukin (IL)-6 and IL-1 β in BALF of mice were detected by enzyme linked immunosorbent assay. The expression levels of Claudin-5, vascular endothelial (VE)-cadherin, vascular endothelial growth factor (VEGF), phospho-protein kinase B (p-Akt) and Akt were detected by Western blot analysis. RESULTS: DMS pre-treatment significantly ameliorated lung histopathological changes. Compared with the LPS group, the W/D ratio and protein contents in BALF were obviously reduced after DMS pretreatment (P<0.05 or P<0.01). The number of cells in BALF and myeloperoxidase (MPO) activity decreased significantly after DMS pretreatment (P<0.05 or P<0.01). DMS pre-treatment decreased the levels of TNF-α, IL-6 and IL-1 β (P<0.01). Meanwhile, DMS activated the phosphoinositide 3-kinase/protein kinase B (PI3K/Akt) pathway and reversed the expressions of Claudin-5, VE-cadherin and VEGF (P<0.01). CONCLUSIONS DMS attenuated LPS-induced ALI in mice through repairing endothelial barrier. It might be a potential therapeutic drug for LPS-induced lung injury.
Mice ; Male ; Animals ; Proto-Oncogene Proteins c-akt/metabolism* ; Lipopolysaccharides ; Phosphatidylinositol 3-Kinases/metabolism* ; Interleukin-1beta/metabolism* ; Vascular Endothelial Growth Factor A/metabolism* ; Tumor Necrosis Factor-alpha/metabolism* ; Claudin-5/metabolism* ; Acute Lung Injury/chemically induced* ; Lung/pathology* ; Interleukin-6/metabolism* ; Drugs, Chinese Herbal

OBJECTIVES: Restoration of blood circulation within "time window" is the principal treating goal for treating acute ischemic stroke. Previous studies revealed that delayed recanalization might cause serious ischemia/reperfusion injury. However, plenty of evidences showed delayed recanalization improved neurological outcomes in acute ischemic stroke. This study aims to explore the role of delayed recanalization on blood-brain barrier (BBB) in the penumbra (surrounding ischemic core) and neurological outcomes after middle cerebral artery occlusion (MCAO). METHODS: Recanalization was performed on the 3rd day after MCAO. BBB disruption was tested by Western blotting, Evans blue dye, and immunofluorescence staining. Infarct volume and neurological outcomes were evaluated on the 7th day after MCAO. The expression of fibroblast growth factor 21 (FGF21), fibroblast growth factor receptor 1 (FGFR1), phosphatidylinositol-3-kinase (PI3K), and serine/threonine kinase (Akt) in the penumbra were observed by immunofluorescence staining and/or Western blotting. RESULTS: The extraversion of Evans blue, IgG, and albumin increased surrounding ischemic core after MCAO, but significantly decreased after recanalization. The expression of Claudin-5, Occludin, and zona occludens 1 (ZO-1) decreased surrounding ischemic core after MCAO, but significantly increased after recanalization. Infarct volume reduced and neurological outcomes improved following recanalization (on the 7th day after MCAO). The expressions of Claudin-5, Occludin, and ZO-1 decreased surrounding ischemic core following MCAO, which were up-regulated corresponding to the increases of FGF21, p-FGFR1, PI3K, and p-Akt after recanalization. Intra-cerebroventricular injection of FGFR1 inhibitor SU5402 down-regulated the expression of PI3K, p-Akt, Occludin, Claudin-5, and ZO-1 in the penumbra, which weakened the beneficial effects of recanalization on neurological outcomes after MCAO. CONCLUSIONS Delayed recanalization on the 3rd day after MCAO increases endogenous FGF21 in the penumbra and activates FGFR1/PI3K/Akt pathway, which attenuates BBB disruption in the penumbra and improves neurobehavior in MCAO rats.
Animals ; Rats ; Blood-Brain Barrier/metabolism* ; Brain Ischemia ; Claudin-5/metabolism* ; Infarction, Middle Cerebral Artery/metabolism* ; Ischemic Stroke/metabolism* ; Occludin/metabolism* ; Phosphatidylinositol 3-Kinases/metabolism* ; Proto-Oncogene Proteins c-akt/metabolism* ; Rats, Sprague-Dawley ; Receptor, Fibroblast Growth Factor, Type 1/metabolism* ; Reperfusion Injury/metabolism*

Objective To investigate the effect of salidroside on intestinal mucosal immune status in rats under compound stress of hypoxia and training (HTCS) and the mechanism. Methods SD rats were randomly divided into HTCS model group (model), placebo group (placebo) and salidroside group (salidro). Model group received no intervention, and placebo and salidro group received intraperitoneal injection of normal saline and salidroside, respectively. Then, ileum tissue of rats were collected and the intestinal damage was assayed by HE staining and Chiu scores. Intestinal permeability indices, including serum D-diamine oxidase (DAO), D-lactic acid (DLA) and endotoxin (END) and secretory immunoglobulin A (sIgA) of intestinal tissue were detected by ELISA. T lymphocyte subsets of intestinal tissue were detected by flow cytometry. Expression of tight junction molecules, including ZO-1, Claudin-3, occluding, were detected by PCR and western blot. Activation of TLR4/NF-κB signaling pathway was detected by Western blot analysis. Results Compared with model group and placebo group, salidro group had the decreased intestinal mucosal injury and low Chiu score, and the level of intestinal permeability indices including serum DAO, DLA and END fell off. CD4⁺ T cell percentage, CD4⁺/CD8⁺ ratio and sIgA level were went up, while CD8⁺ T cell percentage was went down. mRNA and the level of protein expressions of ZO-1, claudin-3 and occludin increased, while activation of TLR4/NF-κB signaling pathway was inhibited. Conclusion Salidroside can alleviate the intestinal barrier injury and improve intestinal mucosal immune status of rats under compound stress of hypoxia and training via inhibiting TLR4/NF-κB signalling pathway.
Animals ; Rats ; Rats, Sprague-Dawley ; NF-kappa B ; Toll-Like Receptor 4/genetics* ; Claudin-3 ; Hypoxia ; Immunoglobulin A, Secretory ; Signal Transduction

OBJECTIVE: To investigate the protective effects and underlying mechanisms of Xuebijing Injection (XBJ) on the lung endothelial barrier in hydrogen sulfide (H METHODS: Sprague-Dawley rats were exposed to H RESULTS: The morphological investigation showed that XBJ attenuated H CONCLUSIONS XBJ ameliorated H
Animals ; Claudin-5 ; Drugs, Chinese Herbal ; Endothelial Cells ; Hydrogen Sulfide ; Phosphatidylinositol 3-Kinases ; Rats ; Rats, Sprague-Dawley ; Respiratory Distress Syndrome/drug therapy*

Bronchopulmonary dysplasia (BPD) has the main manifestations of pulmonary edema in the early stage and characteristic alveolar obstruction and microvascular dysplasia in the late stage, which may be caused by structural and functional destruction of the lung epithelial barrier. The Claudin family is the main component of tight junction and plays an important role in regulating the permeability of paracellular ions and solutes. Claudin-18 is the only known tight junction protein solely expressed in the lung. The lack of Claudin-18 can lead to barrier dysfunction and impaired alveolar development, and the knockout of Claudin-18 can cause characteristic histopathological changes of BPD. This article elaborates on the important role of Claudin-18 in the development and progression of BPD from the aspects of lung epithelial permeability, alveolar development, and progenitor cell homeostasis, so as to provide new ideas for the pathogenesis and clinical treatment of BPD.
Bronchopulmonary Dysplasia/etiology* ; Claudin-3 ; Claudins/genetics* ; Humans ; Infant ; Infant, Newborn ; Infant, Premature ; Lung ; 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

While inflammatory bowel disease (IBD) might be a risk factor in the development of brain dysfunctions, the underlying mechanisms are largely unknown. Here, mice were treated with 5% dextran sodium sulfate (DSS) in drinking water and sacrificed on day 7. The serum level of IL-6 increased, accompanied by elevation of the IL-6 and TNF-α levels in cortical tissue. However, the endotoxin concentration in plasma and brain of mice with DSS-induced colitis showed a rising trend, but with no significant difference. We also found significant activation of microglial cells and reduction in occludin and claudin-5 expression in the brain tissue after DSS-induced colitis. These results suggested that DSS-induced colitis increases systemic inflammation which then results in cortical inflammation via up-regulation of serum cytokines. Here, we provide new information on the impact of colitis on the outcomes of cortical inflammation.
Animals ; Calcium-Binding Proteins ; metabolism ; Caspase 3 ; metabolism ; Cerebral Cortex ; pathology ; Claudin-5 ; metabolism ; Colitis ; chemically induced ; complications ; pathology ; Cytokines ; genetics ; metabolism ; Dextran Sulfate ; toxicity ; Disease Models, Animal ; Encephalitis ; etiology ; Gene Expression Regulation ; drug effects ; Mice ; Microfilament Proteins ; metabolism ; Occludin ; metabolism ; Polysaccharides ; blood ; toxicity ; Time Factors

Ischemic stroke results in the diverse phathophysiologies including blood brain barrier (BBB) disruption, brain edema, neuronal cell death, and synaptic loss in brain. Vitamin C has known as the potent anti-oxidant having multiple functions in various organs, as well as in brain. Dehydroascorbic acid (DHA) as the oxidized form of ascorbic acid (AA) acts as a cellular protector against oxidative stress and easily enters into the brain compared to AA. To determine the role of DHA on edema formation, neuronal cell death, and synaptic dysfunction following cerebral ischemia, we investigated the infarct size of ischemic brain tissue and measured the expression of aquaporin 1 (AQP-1) as the water channel protein. We also examined the expression of claudin 5 for confirming the BBB breakdown, and the expression of bcl 2 associated X protein (Bax), caspase-3, inducible nitric oxide synthase (iNOS) for checking the effect of DHA on the neurotoxicity. Finally, we examined postsynaptic density protein-95 (PSD-95) expression to confirm the effect of DHA on synaptic dysfunction following ischemic stroke. Based on our findings, we propose that DHA might alleviate the pathogenesis of ischemic brain injury by attenuating edema, neuronal loss, and by improving synaptic connection.
Aquaporins ; Aquaporin 1 ; Ascorbic Acid ; bcl-2-Associated X Protein ; Blood-Brain Barrier ; Brain ; Brain Edema* ; Brain Injuries ; Brain Ischemia* ; Caspase 3 ; Cell Death ; Claudin-5 ; Dehydroascorbic Acid* ; Edema ; Neurons ; Nitric Oxide Synthase Type II ; Oxidative Stress ; Post-Synaptic Density ; Stroke

OBJECTIVETo develop an experimental rat model of inflammatory bowel disease (IBD) by administration of dextran sulfate sodium (DSS), and to observe changes in the tight junction protein expression and permeability of colon mucosa.

METHODSMale Sprague-Dawley (SD) rats were randomly divided into control (n=27) and IBD model groups (n=27). In the IBD model group, IBD was induced by 6-day administration of 3% DSS in water followed by 14-day administration of water only. The control group was fed with water only. Pathological changes in colon mucosae were observed on days 7, 14 and 21 after DSS administration. Colon tissue specimens were collected on day 21 for measuring myeloperoxidase (MPO) activity. The transepithelial electric resistance (TEER), transepithelial potential difference (TEPD) and short circuit current (Isc) of the specimens were measured by Ussing chamber. Real-time PCR and Western blot were used to measure the mRNA and protein expression of tight junction proteins in colon epithelia.

RESULTSIn the IBD model group, diarrhea, hemafecia and weight loss were seen. Inflammation occurred mainly in the distal colon and was characterized by crypt abscess and inflammatory cell infiltration. The IBD model group showed significantly increased MPO activity (P<0.01), significantly decreased TEER (P<0.01) and TEPD (P<0.01), and significantly increased Isc (P<0.01) compared with the control group. No claudin 2 expression of mRNA and protein was detected in the control group, and they were expressed in the IBD model group. The expression levels of claudin 3, occludin and ZO-1 in the IBD model group were significantly decreased compared with in the control group (P<0.01).

CONCLUSIONSIBD rats show colonic barrier dysfunction and changes in the expression of tight junction proteins. The changes in the expression of tight junction proteins may contribute to colonic barrier dysfunction in cases of IBD in the chronic recovery stage.

Animals ; Claudin-3 ; analysis ; Colon ; metabolism ; pathology ; Dextran Sulfate ; Disease Models, Animal ; Inflammatory Bowel Diseases ; chemically induced ; metabolism ; Intestinal Mucosa ; metabolism ; Male ; Occludin ; analysis ; Permeability ; Rats ; Rats, Sprague-Dawley ; Tight Junction Proteins ; analysis ; Zonula Occludens-1 Protein ; analysis

OBJECTIVEThe aim of this study was to explore the possibility of creating a toxin, C-CPE-ETA', by fusing C-terminal high affinity binding domain of CPE (C-CPE) with a truncated form of Pseudomonas aeruginosa exotoxin A (ETA') and to examine whether C-CPE-ETA' could specifically target CLDN-3, 4 molecule and the targeted toxin was cytotoxic against CLDN-3,4-overexpressing ovarian cancer.

METHODSCLDN-3 and CLDN-4 expressions were analyzed at the mRNA level in three ovarian cancer cell lines and epithelial ovarian cancer tissues from 20 patients. After transforming an expression plasmid of C-CPE-ETA' into E. coli BL21 (DE3) plysS strain, the recombinant protein was purified using His-Bind resin chromatography column and analyzed by Western blot and Coomassie blue staining. The specific binding, proapoptotic and cytolytic activities were evaluated by flow cytometry, fluorescence microscopy with the JC-1 probe and MTT assay in CLDN-3,4-overexpressing ovarian cancer cells.

RESULTSQuantitive RT-PCR results showed there existed high levels of CLDN-3 and CLDN-4 in ovarian cancer cells, CAOV3, OVCAR3 and SKOV3. Moreover, high expressions of CLDN-3 and CLDN-4 were observed in 90.0% (18/20) and 60.0% (12/20) of ovarian cancer tissues, with an expression level 10-fold higher than that in the normal ovarian tissue. A 58 000 recombinant protein C-CPE-ETA' was demonstrated by Western blot and Coomassie blue staining. Purified and recombinant C-CPE-ETA' was bound with high affinity to CLDN-3,4-overexpressing ovarian cancer cells, CAOV3, OVCAR3 and SKOV3 cells. C-CPE-ETA' was strongly proapoptotic and cytotoxic towards the CLDN-3,4-overexpressing ovarian cancer cells. The concentration of IC(50) was 7.364 ng/ml for CAOV3 cells, 8.110 ng/ml for OVCAR3 cells and 22.340 ng/ml for SKOV3 cells, respectively. However, control CLDN-3,4-deficient cell line HUVEC was not susceptible to the recombinant C-CPE-ETA' at a concentration up to 10 µg/ml.

CONCLUSIONSThe C-CPE-ETA' protein exhibits remarkably specific cytotoxicity for CLDN-3,4-overexpressing ovarian cancer cells. Its therapeutic potential warrants further development for ovarian cancer molecular targeted therapy.

ADP Ribose Transferases ; metabolism ; physiology ; Apoptosis ; Bacterial Toxins ; metabolism ; Cell Line, Tumor ; Claudin-3 ; Claudin-4 ; Claudins ; genetics ; metabolism ; Enterotoxins ; metabolism ; physiology ; Exotoxins ; metabolism ; physiology ; Female ; Humans ; Immunotoxins ; metabolism ; Ovarian Neoplasms ; metabolism ; pathology ; RNA, Messenger ; metabolism ; Recombinant Fusion Proteins ; metabolism ; physiology ; Virulence Factors ; metabolism ; physiology