The functions of TRPP2 in the vascular system.

TRPP2 (polycystin-2, PC2 or PKD2), encoded by the PKD2 gene, is a non-selective cation channel with a large single channel conductance and high Ca(2+) permeability. In cell membrane, TRPP2, along with polycystin-1, TRPV4 and TRPC1, functions as a mechanotransduction channel. In the endoplasmic reticulum, TRPP2 modulates intracellular Ca(2+) release associated with IP3 receptors and the ryanodine receptors. Noteworthily, TRPP2 is widely expressed in vascular endothelial and smooth muscle cells of all major vascular beds, and contributes to the regulation of vessel function. The mutation of the PKD2 gene is a major cause of autosomal dominant polycystic kidney disease (ADPKD), which is not only a common genetic disease of the kidney but also a systemic disorder associated with abnormalities in the vasculature; cardiovascular complications are the leading cause of mortality and morbidity in ADPKD patients. This review provides an overview of the current knowledge regarding the TRPP2 protein and its possible role in cardiovascular function and related diseases.

Orai1 forms a signal complex with SK3 channel in gallbladder smooth muscle.

Orai1 is one of the key components of store-operated Ca(2+) entry (SOCE) involved in diverse physiological functions. Orai1 may associate with other proteins to form a signaling complex. In the present study, we investigated the interaction between Orai1 and small conductance Ca(2+)-activated potassium channel 3 (SK3). With the use of RNA interference technique, we found that the SOCE and its associated membrane hyperpolarization were reduced while Orai1 was knocked down by a specific Orai1 siRNA in guinea pig gallbladder smooth muscle. However, with the use of isometric tension measurements, our results revealed that agonist-induced muscle contractility was significantly enhanced after Orai1 protein was knocked down or the tissue was treated by SK3 inhibitor apamin, but not affected by larger conductance Ca(2+)-activated potassium channel inhibitor iberiotoxin or intermediate conductance Ca(2+)-activated potassium channel inhibitor TRAM-34. In addition, in the presence of apamin, Orai1 siRNA had no additional effect on agonist-induced contraction. In coimmunoprecipitation experiment, SK3 and Orai1 pulled down each other. These data suggest that, Orai1 physically associated with SK3 to form a signaling complex in gallbladder smooth muscle. Ca(2+) entry via Orai1 activates SK3, resulting in membrane hyperpolarization in gallbladder smooth muscle. This hyperpolarizing effect of Orai1-SK3 coupling could serve to prevent excessive contraction of gallbladder smooth muscle in response to contractile agonists.

c-Met function requires N-linked glycosylation modification of pro-Met.

c-Met, the receptor for hepatocyte growth factor (HGF), is cell surface tyrosine kinase that controls cancer cell growth, survival, invasion, and metastasis. Post-translational modification, such as glycosylation, plays an essential role in regulating the function of cell surface molecules. Whether glycosylation modification regulates the enzymatic properties of c-Met is unknown. In this study, we investigated the effect of glycosylation on the function of c-Met. We found that c-Met is an N-linked glycosylated protein. Both pro-Met and p145Met (the ß subunit of mature c-Met) have N-linked glycosylation. Glycosylation inhibitor studies revealed that the N-glycosylation modification of p145Met is from pro-Met, but not due to the further modification of pro-Met. Importantly, blocking the N-glycosylation targets pro-Met to cytoplasm and initiates its phosphorylation independent of HGF engagement. Nonglycosylated pro-Met activates c-Met downstream pathways to a certain extent to compensate for the degradation of p145Met induced by glycosylation blocking-mediated endoplasmic reticulum (ER) stress.

NTCP Change in Rats of Hilar Cholangiocarcinoma and Therapeutic Significance.

Background: The study aims to detect the expression of Na+/taurocholate cotransporter polypeptide in hilar cholangiocarcinoma of rat model, to provide a new therapeutic target for gene therapy of hilar cholangiocarcinoma. Methods: 60 male Wistar rats (weighing 190 ± 8 g) were randomly divided into 3 groups (experimental group, control group, and sham operation group; 20 rats in each group). The 3 groups were fed with standard diet. The QBC939 cell suspension of cholangiocarcinoma was injected into the hilar bile duct in the experimental group with a micro syringe. The control group was injected with normal saline, and the sham operation group was not injected with any drugs. Comprehensive behavior score and Basso Beattie Bresnahan were used to evaluate the mental state and exercise of rats every day. At 5 weeks, one rat in the experimental group was killed, and the changes in hilar bile duct were recorded. The procedure was repeated at one and half months. After one and half months, hilar cholangiocarcinoma only occurred in the experimental group. Pathological examination confirmed the formation of tumor, and hilar bile duct tissues were taken from the 3 groups. Na+/taurocholate cotransporter polypeptide expression in hilar bile duct was detected by real-time polymerase chain reaction and immunohistochemistry. Results: After 2 weeks, the rats in experimental group ate less, and their weight was significantly reduced compared with the other 2 groups. One and half months later, hilar cholangiocarcinoma was detected in 16 rats in the experimental group. The levels of alanine aminotransferase and aspartate transaminase in the experimental group were higher than those in the other 2 groups. The ratio of Na+/taurocholate cotransporter polypeptide/GAPDH mRNA in hilar cholangiocarcinoma, control group, and sham operation group was significantly different. Under the light microscope, Na+/taurocholate cotransporter polypeptide protein reacted with anti-Na+/taurocholate cotransporter polypeptide antibody and showed granular expression. Every pathological section included 4800 cells. 3823 positive cells were in the experimental group, 1765 positive cells were in the control group, and 1823 positive cells were in the sham operation group. Conclusions: Na+/taurocholate cotransporter polypeptide expression in hilar cholangiocarcinoma of rats was significantly higher than normal hilar bile duct tissues, suggesting that drugs targeting Na+/taurocholate cotransporter polypeptide may be a new strategy for the treatment of hilar cholangiocarcinoma.

Effect of FXR agonist GW4064 in the treatment of hilar cholangiocarcinoma in rats.

The study objective was to observe the treatment effect of the farnesoid X receptor (FXR) agonist GW4064 in a rat model of hilar cholangiocarcinoma to explore a new therapeutic target for gene therapy for hilar cholangiocarcinoma. Eighty male Wistar rats were randomly divided into four groups (treatment group, model group, control group and sham operation group, 20 rats in each group). The four groups were fed a standard diet. The treatment group and the model group were injected with a suspension of cholangiocarcinoma QBC939 cells into the hilar bile duct with a microsyringe, the control group was injected with normal saline, and the sham operation group was not injected with anything. A modified tail suspension test (TST) was used to evaluate the vitality of the rats. At 4 weeks, one rat in the treatment group and model group was euthanized, and the changes in the hilar bile duct were recorded. The procedure was repeated at 6 weeks. After 6 weeks, hilar cholangiocarcinoma occurred in the treatment group and model group. Then, the treatment group was injected with GW4064 intraperitoneally at a dose of 50 mg/kg/day. One week after injection, the rats in the four groups were euthanized. Pathological examination confirmed that tumours had formed, and hilar bile duct tissues were taken from the four groups. FXR, Bsep, Ntcp and NF-κB expression in the hilar bile duct was detected by real-time polymerase chain reaction (RT-PCR) and immunohistochemistry. After three weeks, the rats in the treatment group and model group ate less, and their weight was significantly reduced. Six weeks later, hilar cholangiocarcinoma was detected in the treatment group and model group. After treatment with GW4064, the ratios of FXR/GAPDH mRNA, Bsep/GAPDH mRNA, Ntcp/GAPDH mRNA and NF-κBp65/GAPDH mRNA were significantly different among the four groups. Under a light microscope, FXR protein reacted with anti-FXR antibody, Bsep protein reacted with anti-Bsep antibody, Ntcp protein reacted with anti-Ntcp antibody and NF-κBp65 protein reacted with anti-NF-κBp65 antibody, and they showed granular expression. Every pathological section included 4,800 cells, and there were different numbers of positive cells in each group. FXR expression in the hilar cholangiocarcinoma of rats was significantly lower than that in normal hilar bile duct tissues. GW4064 increased the expression of FXR in tumour tissues. These findings suggest that FXR may be a new therapeutic target and that GW4064 may be helpful in the treatment of hilar cholangiocarcinoma.

[Expressions and significance of COX-2 and P-gp in human hepatocellular carcinoma tissues].

OBJECTIVE: To investigate the effect of the COX-2 gene on the oncogenesis and development of the hepatocellular carcinoma and the influence of COX-2 gene on the expression of P-gp protein. METHOD: Fifty-two pieces of the hepatocellular carcinoma samples and 20 cases of normal liver samples were collected from the patients operated from October 2003 to June 2005. RT-PCR and immunohistochemistry staining were employed to detect the COX-2 mRNA as well as P-gp protein in the normal liver tissues and the carcinoma tissues. Meanwhile, the expression of the mdr 1 mRNA in the carcinoma tissues was also determined and the correlation between the expressions of the COX-2 and P-gp was investigated. RESULTS: No expression of the COX-2 in the normal liver tissue was detected. The positive expression of COX-2 in the low and middle differentiated carcinoma was elevated significantly as compared with that in the high differentiated carcinoma tissue (x2 = 6.80, P less than 0.01). The positive expression of the COX-2 in the HBSAg (+) carcinoma tissue was significantly higher as compared with that in the HBSAg (-) carcinoma (x2 = 4.70, P less than 0.05), and the carcinoma in combination with cirrhosis also showed significantly higher in expression of COX-2 than the carcinoma without cirrhosis (x2 = 7.51, P less than 0.01). The mdr1 mRNA was found both expressed in the normal and carcinoma tissues. The expression of COX-2 mRNA was found in the carcinoma, but not found in the normal tissues. The COX-2 mRNA and mdr1 mRNA was found both expressed in the normal and carcinoma tissues. The correlation coefficient between COX-2 and mdr1 mRNA was 0.563 ( P less than 0.01). CONCLUSION: The results indicated that Cox-2 gene might involved in the multidrug resistance of the hepatocellular carcinoma mediated by P-gp.

Bsep expression in hilar cholangiocarcinoma of rat model.

Develop a rat model of hilar cholangiocarcinoma for detecting bile salt export pump (Bsep) expression in hilar cholangiocarcinoma tissues, in order to provide a new therapeutic target for the gene therapy of hilar cholangiocarcinoma. Sixty male Wistar rats (body weight, 190 ± 8 g) were randomly divided into three groups (the experimental group, the control group and the sham operation group, n = 20 each) as follows: The three groups were fed a standard diet, the experimental group was injected by cholangiocarcinoma QBC939 cell suspension along the hilar bile duct into the bile duct bifurcation with microsyringe, the control group was injected by normal saline, the sham operation group did not inject anything. Every day assess the rats' mental state, diet, and motion by using Basso-Beattie-Bresnahan and combined behavioral score. At 4 weeks, one rat of the experimental group was sacrificed after it was administered anesthesia, and we recorded changes in hilar bile duct size, texture, and form. This procedure was repeated at 6 weeks. After 6 weeks, hilar cholangiocarcinoma developed only in the experimental group, thereby establishing an experimental model for studying QBC939-induced hilar cholangiocarcinoma. Tumor formation was confirmed by pathological examination, and hilar bile duct tissues were harvested from both the groups. A real-time polymerase chain reaction assay and an immunohistochemical assay were used to analyze the expression of Bsep in hilar bile duct tissues of each group. From the second week, the rats in experimental group began to eat less, and their body mass decreased compared with control group and sham operation group. After 6 weeks, we detected hilar cholangiocarcinoma in the hilar bile duct tissues of 18 rats (90%) in the experimental group. In the experimental group with hilar cholangiocarcinoma, we found that the levels of total cholesterol, total bilirubin, and direct bilirubin were higher compared with those in the control group and sham operation group. Simultaneously, muddy stones emerged from the bile ducts of rats in the experimental group. The Bsep/Gapdh mRNA ratio in hilar cholangiocarcinoma, control group and sham operation group differed markedly. Light microscopy revealed a granular pattern of Bsep protein expression which reacted with the anti-Bsep antibody. Each section was randomly divided into six regions, with 80 cells were observed in every region. Sections with > 10% positive cells were designated positive, Sections with < 10% positive cells were designated negative. Each group included 4800 cells. In the experimental group, 1200 cells (25%) were positive, in the control group, 3648 cells (76%) were positive and in the sham operation group 3598 cells (75%) were positive, and this difference was statistically significant. Bsep expression significantly decreased in hilar cholangiocarcinoma of rats than those in control group and sham operation group, suggesting that drugs targeting Bsep are a new strategy for hilar cholangiocarcinoma.

The effect of transient receptor potential vanilloid 4 on the intestinal epithelial barrier and human colonic cells was affected by tyrosine-phosphorylated claudin-7.

TRPV4 is a type of nonselective cation channel, and activation of TRPV4 in the gastrointestinal tract causes experimental colitis in mice. A previous study found that tyrosine-phosphorylated claudin-7 is increased in experimental colitis. The relationship between tyrosine-phosphorylated claudin-7 and TRPV4 remains undefined. In the present study, we developed a claudin-7 mutant by replacing tyrosine with glutamic acid at position 210, named cld7-Y210E colonic cells. We found that activation of TRPV4 by GSK1016790A increased the permeability of control colonic cell monolayers, which was decreased by the TRPV4 antagonist HC067047. In monolayers of cld7-Y210E colonic cells, no differences in permeability were found between GSK1016790A and HC067047 treatments. GSK1016790A increased the aggregation of claudin-7 at the cell membrane in control colonic cells, and the effect was diminished by HC067047. In cld7-Y210E colonic cells, neither GSK1016790A nor HC067047 apparently changed the aggregation of claudin-7. Neither GSK1016790A nor HC067047 altered the TRPV4 protein level in vector colonic cells. In cld7-wild colonic cells, GSK1016790A did not alter the TRPV4 protein level, while HC067047 increased the TRPV4 protein level. The TRPV4 protein level was increased in cld7-Y210E colonic cells, decreased by GSK1016790A and further decreased by HC067047. Calcium influx was not significantly changed in the control colonic cells treated with GSK1016790A. However, GSK1016790A significantly increased calcium influx in cld7-Y210E colonic cells. We concluded that tyrosine-phosphorylated claudin-7 affects the TRPV4-modulated intestinal epithelial barrier, TRPV4-mediated calcium influx, and the protein expression of TRPV4 in human colonic cells. We suggest that tyrosine-phosphorylated claudin-7 affects the TRPV4-modulated intestinal epithelial barrier, which might be related to TRPV4 expression and TRPV4-mediated calcium influx.

Kaempferol from Penthorum chinense Pursh suppresses HMGB1/TLR4/NF-κB signaling and NLRP3 inflammasome activation in acetaminophen-induced hepatotoxicity.

Acetaminophen (APAP) is one of the safest and most effective over-the-counter (OTC) analgesics and antipyretics, but excessive doses of APAP will induce hepatotoxicity with high morbidity and mortality worldwide. Kaempferol (KA), a flavonoid compound derived from the medicinal and edible plant of Penthorum chinense Pursh, has been reported to exert a profound anti-inflammatory and antioxidant activity. In this study, we explored the protective effect and novel mechanism of KA against APAP-induced hepatotoxicity. The results revealed that KA pretreatment significantly reduced the levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT), relieved hepatocellular damage and apoptosis, attenuated the exhaustion of glutathione (GSH) and accumulation of malondialdehyde (MDA), increased the expression of antioxidative enzymes (e.g., heme oxygenase 1 (HO-1) and NADPH quinone oxidoreductase 1 (NQO1)), and thus restrained APAP-induced oxidative damage in the liver. KA suppressed the expression of NLRP3 and reduced the levels of pro-inflammatory factors, including interleukin-1 beta (IL-1ß), tumor necrosis factor-alpha (TNF-α), and interleukin-6 (IL-6). Moreover, KA remarkably inhibited high-mobility group box 1 (HMGB1) and toll-like receptor 4 (TLR4) expression as well as nuclear factor kappa-B (NF-κB) activation for liver protection against APAP-induced inflammatory responses and apoptosis. Taken together, our findings suggested that KA could effectively protect hepatocytes from APAP hepatotoxicity through the up-regulation of HO-1 and NQO1 expression, the down-regulation of NLRP3 expression, and the inhibition of the HMGB1/TLR4/NF-κB signaling pathway.

Emodin and baicalein inhibit pancreatic stromal derived factor-1 expression in rats with acute pancreatitis.

BACKGROUND: Stromal derived factor-1 (SDF-1) is an efficacious leukocyte chemoattractant, which can attract lymphocytes and mononuclear cells from bloodstream into the site of inflammation. Emodin, an anthraquinone derivative from Radix et Rhizoma Rhei, and baicalein, a flavone from Scutellaria baicalensis Georgi, both have been reported to possess anti-inflammatory activities. The expression pattern of SDF-1 in experimental acute pancreatitis (AP) and the effect of emodin or baicalein on that are not well defined. The present study aimed to investigate the effects of emodin and baicalein on pancreatic myeloperoxidase (MPO) activity (reflecting leukocyte sequestration) and cytokine production, as well as tissue SDF-1 expression in the setting of AP. METHODS: A rat model of AP was induced by administration of 5% sodium taurocholate through the biliopancreatic duct. The level of tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6) and MPO in the pancreas, and serum amylase were tested by immunohistochemistry, ELISA and chromatometry. The expressions of SDF-1 alpha and SDF-1 beta were detected by real-time PCR, Western blotting, and immunohistochemistry. RESULT: Combination of emodin and baicalein significantly reduced pancreatic TNF-alpha, IL-6 and MPO, and also inhibited pancreatic SDF-1 expression. CONCLUSIONS: The inhibition of SDF-1 expression by emodin and baicalein might contribute, in part at least, to the amelioration of pancreatic inflammation. The present study also shows benefits of simultaneous treatment of AP.

Morphological changes of blood spleen barrier in portal hypertensive spleen.

BACKGROUND: The pathogenesis of hypersplenism and the immune function of the spleen in patients with portal hypertension (PH) remain obscure. This study aimed to evaluate the morphological changes of blood spleen barrier in spleen with hypersplenism due to PH and provide evidence for an in-depth investigation of the immune function of the spleen with hypersplenism and the mechanism of hypersplenism. METHODS: Spleen samples from 12 portal hypertensive patients and 4 patients with traumatic ruptures of spleen were examined. The samples of spleen were made into pathological sections, stained with Masson trichrome stain, Gomori stain, and CD68, CD34 immunohistochemistry, and were examined microscopically for the changes in the distribution of collagen fibers, reticular fibers, macrophages, and vascular endothelial cells. The changes in ultrastructure of macrophages and endothelial cells in marginal zone were also evaluated by transmission electron microscopy. RESULTS: As compared to the normal spleen, the density of macrophage in the PH spleen was decreased, but the macrophages were mainly located in the marginal zone and distributed around the splenic corpuscle, with many villi and pseudopodium-like protrusion on the cell surface. The accrementition of collagen fibers was obvious around the splenic corpuscle and central artery. The increased reticulate fibers encircled the splenic corpuscle with more connection between the fibers. The vascular endothelial cells were in diffused distribution, without any regionality in PH spleen, but the vessel with enlarged lumina increased in red pulp. CONCLUSIONS: The morphological changes of the blood spleen barrier can be one of the pathological fundaments for the abnormality of the immune function and the increased destruction of blood cells located in the spleens of patients with PH. However, this still entails clarification.

The effect of serine phosphorylated claudin-7 on the epithelial barrier and the modulation by transient receptor potential vanilloid 4 in human colonic cells.

Abnormal phosphorylation of claudins changes the interaction and aggregation of tight junction proteins, affecting the intestinal epithelial barrier. Selective blockade of transient receptor potential vanilloid 4 (TRPV4) alleviated experimental colitis. Whether TRPV4 affects the intestinal epithelial barrier and the relationship to claudin-7 phosphorylation remain unknown. In the present study, we investigated the TRPV4 expression in human colonic tissues and colonic cells. Using the site-directed mutagenesis approach, we also identified the roles of claudin-7 phosphorylation in the epithelial barrier and the relationship between TRPV4 and claudin-7 phosphorylation. Increased TRPV4 expression was found in the colonic mucosa from IBD patients. In colonic cells, the mutation of claudin-7 at position 204 decreased the TRPV4 expression. Mutation of claudin-7 at position 204 significantly decreased the FD20 permeability in monolayer colonic cells, while mutations of claudin-7 at positions S206 and S207 increased the FD20 permeability. Meanwhile, mutations of claudin-7 at positions S204 and S207 increased the TER in monolayer colonic cells. TRPV4 agonist GSK1016790 A increased the FD20 permeability in the control group, cld7-wild group, cld7-S206A group and cld7-S207 A group, while the TRPV4 antagonist HC067047 decreased the FD20 permeability in the same groups. HC067047 treatment increased the TER in vector cells, cld7-wild cells and cld7-S206 A cells compared to the respective cells in GSK1016790A-treated groups. HC067047 treatment decreased the migration in vector cells, cld7-wild cells and cld7-S206 A cells compared to the respective cells in the GSK1016790A-treated groups. These results indicated that TRPV4 might be a target for the maintenance of the intestinal epithelial barrier and indicated the mechanism involved in the modulation of serine phosphorylated claudin-7.

Different Effects of Hypertension and Age on the Function of Large Conductance Calcium- and Voltage-Activated Potassium Channels in Human Mesentery Artery Smooth Muscle Cells.

BACKGROUND: Large-conductance calcium- and voltage-activated potassium channels (BKC a channels) play important roles in the maintenance of vascular tone, and their dysregulation is associated with abnormal vascular relaxation and contraction. We tested the changes in BKC a channel properties in patients at different ages to assess the effects of hypertension and aging on the functional changes of BKC a channels. METHODS AND RESULTS: Patch clamp was performed to detect the activities of BKC a channels in freshly isolated human mesenteric artery smooth muscle cells from younger patients (aged ≤45 years) without hypertension, older patients (aged ≥65 years) without hypertension, and older patients with hypertension. The expression of mRNA and protein from BKC a channels was evaluated by reverse transcription polymerase chain reaction and Western blot analysis, respectively. Results showed that the whole-cell current density, spontaneous transient outward current, and Ca(2+) sensitivity of the artery smooth muscle cells were significantly decreased in the older patients with hypertension; the decreases were insignificant in the older patients without hypertension, although a clear tendency to have spontaneous transient outward current was detected in these patients. The expression of both mRNA and protein of BKC a subunits α and ß1 was significantly decreased in the older patients with hypertension but not in the older patients without hypertension compared with the younger patients without hypertension. CONCLUSIONS: Our findings demonstrate for the first time that hypertension is an important factor for the pathological alteration of the properties of BKC a channels in human mesenteric artery smooth muscle cells, and aging itself may also be a factor in these changes in the cells.

Changes in the phosphorylation of claudins during the course of experimental colitis.

The phosphorylation of the tight-junction protein claudin causes allosterism, endocytosis and changes in the polarity of the epithelium, thus affecting the barrier function. The phosphorylation status of claudin during the course of colitis has not been demonstrated. In the present study, we found that the phosphorylated claudin-4 and claudin-7 contents were increased in experimental colitis at days 6 and 8, and colonic phosphorylated claudin-6 was found to be increased at day 4 and day 8. Colonic phosphorylated claudin-5 was found to be decreased at day 4 but increased at day 6. These changes were accompanied by increases in intestinal permeability. In T84 cells, phosphorylated claudin-3 was increased at 48 h but decreased at 72 h after lipopolysaccharide (LPS) treatment. Phosphorylated claudin-5 and claudin-7 were decreased 72 h after LPS treatment, while phosphorylated claudin-6 was increased at 72 h after LPS treatment. We conclude that the phosphorylation of colonic claudins was changed during the course of colitis, which may be related to the change in the intestinal barrier function. Cytokine such as LPS was found to affect the phosphorylation of colonic claudins.

Rabeprazole 10 mg versus 20 mg in preventing relapse of gastroesophageal reflux disease: a meta-analysis.

BACKGROUND: Several randomized controlled trials (RCTs) have compared endoscopic and symptomatic relapses in patients with erosive gastroesophageal reflux disease (GERD). We have summarized current evidence for rabeprazole 10 or 20 mg once daily for GERD maintenance treatment over 1 or 5 years. METHODS: MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials were searched, through August 2012, for eligible RCTs of adults with erosive GERD. The efficacies of rabeprazole 10 and 20 mg/d were compared. RESULTS: The search identified 288 citations, and five RCTs containing 1480 patients were considered eligible. Heartburn relapse rates did not differ significantly between patients treated with rabeprazole 10 and 20 mg/d for 1 year (relative risk (RR) = 1.29; 95% confidence interval (CI): 0.97-1.72), but differed in patients treated for 5 years (RR = 1.274; 95% CI: 1.005-1.615). Endoscopic relapse rates differed significantly between rabeprazole 10 and 20 mg/d for 1 year (RR = 1.92; 95% CI: 1.21-3.06), for 5 years (RR = 1.667; 95% CI: 1.073-2.589), and in combined 1- and 5-year maintenance trials (RR = 1.785; 95% CI: 1.298-2.456). CONCLUSION: Rabeprazole 20 mg/d was superior to rabeprazole 10 mg/d in preventing endoscopic relapse of erosive GERD, but that the two dosages were equivalent in symptomatic relief over 1 year.

Emodin promoted pancreatic claudin-5 and occludin expression in experimental acute pancreatitis rats.

AIM: To investigate the effect of emodin on pancreatic claudin-5 and occludin expression, and pancreatic paracellular permeability in acute pancreatitis (AP). METHODS: Experimental pancreatitis was induced by retrograde injection of 5% sodium taurocholate into the biliopancreatic duct. Emodin was injected via the external jugular vein 0 or 6 h after induction of AP. Rats from sham operation and AP groups were injected with normal saline at the same time. Samples of pancreas were obtained 6 or 12 h after drug administration. Pancreatic morphology was examined with hematoxylin and eosin staining. Pancreatic edema was estimated by measuring tissue water content. Tumor necrosis factor (TNF)-α and interleukin (IL)-6 level were measured by enzyme-linked immunosorbent assay. Pancreatic paracellular permeability was assessed by tissue dye extravasation. Expression of pancreatic claudin-5 and occludin was examined by immunohistology, quantitative real-time reverse transcriptase polymerase chain reaction and western blotting. RESULTS: Pancreatic TNF-α and IL-6 levels, wet/dry ratio, dye extravasation, and histological score were significantly elevated at 3, 6 and 12 h following sodium taurocholate infusion; treatment with emodin prevented these changes at all time points. Immunostaining of claudin-5 and occludin was detected in rat pancreas, which was distributed in pancreatic acinar cells, ductal cells and vascular endothelial cells, respectively. Sodium taurocholate infusion significantly decreased pancreatic claudin-5 and occludin mRNA and protein levels at 3, 6 and 12 h, and that could be promoted by intravenous administration of emodin at all time points. CONCLUSION: These results demonstrate that emodin could promote pancreatic claudin-5 and occludin expression, and reduce pancreatic paracellular permeability.

CXCR4 antagonist AMD3100 modulates claudin expression and intestinal barrier function in experimental colitis.

Ulcerative colitis is a gastrointestinal disorder characterized by local inflammation and impaired epithelial barrier. Previous studies demonstrated that CXC chemokine receptor 4 (CXCR4) antagonists could reduce colonic inflammation and mucosal damage in dextran sulfate sodium (DSS)-induced colitis. Whether CXCR4 antagonist has action on intestinal barrier and the possible mechanism, is largely undefined. In the present study, the experimental colitis was induced by administration of 5% DSS for 7 days, and CXCR4 antagonist AMD3100 was administered intraperitoneally once daily during the study period. For in vitro study, HT-29/B6 colonic cells were treated with cytokines or AMD3100 for 24 h until assay. DSS-induced colitis was characterized by morphologic changes in mice. In AMD3100-treated mice, epithelial destruction, inflammatory infiltration, and submucosal edema were markedly reduced, and the disease activity index was also significantly decreased. Increased intestinal permeability in DSS-induced colitis was also significantly reduced by AMD3100. The expressions of colonic claudin-1, claudin-3, claudin-5, claudin-7 and claudin-8 were markedly decreased after DSS administration, whereas colonic claudin-2 expression was significantly decreased. Treatment with AMD3100 prevented all these changes. However, AMD3100 had no influence on claudin-3, claudin-5, claudin-7 and claudin-8 expression in HT-29/B6 cells. Cytokines as TNF-α, IL-6, and IFN-γ increased apoptosis and monolayer permeability, inhibited the wound-healing and the claudin-3, claudin-7 and claudin-8 expression in HT-29/B6 cells. We suggest that AMD3100 acted on colonic claudin expression and intestinal barrier function, at least partly, in a cytokine-dependent pathway.

Emodin enhances alveolar epithelial barrier function in rats with experimental acute pancreatitis.

AIM: To investigate the effect of emodin on expression of claudin-4, claudin-5 and occludin, as well as the alveolar epithelial barrier in rats with pancreatitis induced by sodium taurocholate. METHODS: Experimental pancreatitis was induced by retrograde injection of 5% sodium taurocholate into the biliopancreatic duct. Emodin was injected via the external jugular vein 3 h after induction of acute pancreatitis. Rats from sham operation group and acute pancreatitis group were injected with normal saline (an equivalent volume as emodin) at the same time point. Samples of lung and serum were obtained 6 h after drug administration. Pulmonary morphology was examined with HE staining. Pulmonary edema was estimated by measuring water content in lung tissue samples. Tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) level were measured by enzyme-linked immunospecific assay. Serum amylase and pulmonary myeloperoxidase (MPO) activity were detected by spectrophotometry. Alveolar epithelial barrier was assessed by pulmonary dye extravasation. Expression of claudin-4, claudin-5 and occludin in lung tissue samples was examined by immunohistology, quantitative real-time reverse transcription polymerase chain reaction and Western blotting analysis, respectively. RESULTS: Pancreatitis-associated lung injury was characterized by pulmonary edema, leukocyte infiltration, alveolar collapse, and elevated serum amylase level. The pulmonary damage, pulmonary pathological scores, serum amylase and MPO activity, TNF-alpha and IL-6 levels, and wet/dry ratio were decreased in rats after treatment with emodin. Immunostaining of claudin-4, claudin-5 and occludin was detected in lung tissue samples from rats in sham operation group, which was distributed in alveolar epithelium, vascular endothelium, and bronchial epithelium, respectively. The mRNA and protein expression levels of claudin-4, claudin-5 and occludin in lung tissue samples were markedly decreased, the expression level of claudin-4, claudin-5 and occluding was increased, and the pulmonary dye extravasation was reduced in lung tissue samples from rats with acute pancreatitis after treatment with emodin. CONCLUSION: Emodin attenuates pulmonary edema and inflammation, enhances alveolar epithelial barrier function, and promotes expression of claudin-4, claudin-5 and occludin in lung tissue samples from rats with acute pancreatitis.

CXCR4 antagonist AMD3100 attenuates colonic damage in mice with experimental colitis.

AIM: To investigate the effects of the chemokine stromal cell-derived factor-1 (CXCL12) receptor (CXCR4) antagonist AMD3100 on colonic inflammation and epithelial barrier in dextran sulfate sodium (DSS)-induced colitis in mice. METHODS: Experimental colitis was induced by administration of 5% DSS for 7 d, and assays performed on intestinal segments from the ileocecal valve to the anus. Colonic morphology was examined by hematoxylin and eosin staining. Colonic cytokines were determined by enzyme-linked immunosorbent assay. Myeloperoxidase (MPO) activity (indicator of inflammatory infiltration) was observed spectrophotometrically. Gut permeability was assessed by mucosal-to-serosal clearance of fluorescein isothiocyanate-conjugated dextran 4000 (FD4) in everted gut sacs. The apoptosis of colonic epithelium was assessed by Hoechst-33342 staining. To further elucidate the role of CXCR4 in colonic inflammation, we also investigated the effect of AMD3100 on migration and cytokine production of isolated peripheral blood mononuclear cells (PBMCs). RESULTS: DSS-induced colitis was characterized by morphologic changes, as well as increased colonic cytokines, inflammatory infiltration, epithelial apoptosis, and intestinal permeability in mice. In AMD3100-treated mice, epithelial destruction, inflammatory infiltration, and submucosal edema were markedly reduced; colonic tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6) and interferon-gamma (IFN-gamma) levels, as well as MPO activity were significantly decreased. Increased intestinal permeability in DSS-treated mice was significantly reduced by AMD3100. The number of apoptotic cells in colitis mice was markedly increased after DSS administration, and decreased when treated with the CXCR4 antagonist AMD3100. In pre-activated PBMCs, CXCL12 stimulation significantly increased the migration of PBMCs, and was inhibited by AMD3100. Moderately increased TNF-alpha, IL-6, and IFN-gamma from CXCL12-treated PBMCs were also reduced by AMD3100. CONCLUSION: The CXCR4 antagonist AMD3100 exerts therapeutic effects on experimental colitis by inhibiting colonic inflammation and enhancing epithelial barrier integrity.

Induction of apoptosis and cell cycle arrest in human HCC MHCC97H cells with Chrysanthemum indicum extract.

AIM: To investigate the effects of Chrysanthemum indicum extract (CIE) on inhibition of proliferation and on apoptosis, and the underlying mechanisms, in a human hepatocellular carcinoma (HCC) MHCC97H cell line. METHODS: Viable rat hepatocytes and human endothelial ECV304 cells were examined by trypan blue exclusion and MTT assay, respectively, as normal controls. The proliferation of MHCC97H cells was determined by MTT assay. The cellular morphology of MHCC97H cells was observed by phase contrast microscopy. Flow cytometry was performed to analyze cell apoptosis with annexin V/propidium iodide (PI), mitochondrial membrane potential with rhodamine 123 and cell cycle with PI in MHCC97H cells. Apoptotic proteins such as cytochrome C, caspase-9, caspase-3 and cell cycle proteins, including P21 and CDK4, were measured by Western blotting. RESULTS: CIE inhibited proliferation of MHCC97H cells in a time- and dose-dependent manner without cytotoxicity in rat hepatocytes and human endothelial cells. CIE induced apoptosis of MHCC97H cells in a concentration-dependent manner, as determined by flow cytometry. The apoptosis was accompanied by a decrease in mitochondrial membrane potential, release of cytochrome C and activation of caspase-9 and caspase-3. CIE arrested the cell cycle in the S phase by increasing P21 and decreasing CDK4 protein expression. CONCLUSION: CIE exerted a significant apoptotic effect through a mitochondrial pathway and arrested the cell cycle by regulation of cell cycle-related proteins in MHCC97H cells without an effect on normal cells. The cancer-specific selectivity shown in this study suggests that the plant extract could be a promising novel treatment for human cancer.