Background: Aquaporins (AQPs), the family of water-selective channels, are localized in various organs and tissues, including the gastrointestinal (GI) tract. However, the roles of AQPs in the GI tract remain unclear....Background: Aquaporins (AQPs), the family of water-selective channels, are localized in various organs and tissues, including the gastrointestinal (GI) tract. However, the roles of AQPs in the GI tract remain unclear. Materials and Methods: Male SD rats were subjected to subtotal colectomy (Group C, n = 22) or a sham operation (Group S, n = 16) and were sacri-ficed on postoperative days 7, 14, and 28. Total RNAs from the distal ileum and rectum were extracted. Quantitative RT-PCR was performed to measure AQP8 mRNA expression. For light-microscopy or immunohistochemistry, paraffin-embedded sections of 4 μm were prepared with H-E staining or anti-AQP8 antibody reaction. Mann-Whitney U-test was performed to compare the AQP8 distributions between the two groups, and the statistical significance was defined as展开更多
Backgrounds: Aquaporins (AQPs), the mammalian water channels, have been localized in various organs, including the gastrointestinal (GI) tract. We examined AQPs expression in rat models of massive intestineal resectio...Backgrounds: Aquaporins (AQPs), the mammalian water channels, have been localized in various organs, including the gastrointestinal (GI) tract. We examined AQPs expression in rat models of massive intestineal resection to determine the functions of AQPs in the GI tract. Methods: Female Sprague-Dawley rats (n = 15) underwent 90% resection of the small intestine, and Female Wistar-Kyoto rats (n = 10), received subtotal colectomy, and were sacrificed following the operations. RNase protection assay and quantitative reverse transcription-polymerase chain reaction (RT-PCR) were performed to measure the AQPs mRNA expression in the GI tract. Immunohistochemistry was performed to confirm AQP8 protein expression. Results: AQP8 mRNA expression (mean ± standard error), was enhanced in the jejunum of the short bowel rats at days 7 and 14 (37.6% ± 1.4% and 18.5% ± 2.4%, respectively, p < 0.01). Enhancement of AQP8 mRNA was also observed in the remnant rectum of the subtotal colectomized rats at both days 21 and 42 (116.1% ± 4.5% and 143.3% ± 7.4%, respectively, p < 0.01). Immunohistochemistry demonstrated enhanced AQP8 expression in the remnant rectum of the subtotal colectomized rats. No intensive change was observed with other AQPs in both models. Conclusions: Our results suggest a compensatory role of AQP8 in the maintenance of intestinal fluid balance.展开更多
Background The relationship between melanosis coli （MC） and aquaporin 8 （AQP8） has not yet been elucidated. The aim of this research was to investigate the relationship between the expression of AQP8 and the patho...Background The relationship between melanosis coli （MC） and aquaporin 8 （AQP8） has not yet been elucidated. The aim of this research was to investigate the relationship between the expression of AQP8 and the pathological mechanism of MC.Methods Expression of AQP8 was detected by immunohistochemistry and reverse transcription-polymerase chain reaction （RT-PCR） in 37 MC colon tissues and 13 control colon tissues. Global gene expression analysis was also used to identify differently expressed genes. Its relationship with MC was analyzed by SPSS 11.5 statistical software.Results The positive rate of AQP8 expression detected by immunohistochemistry in the MC group was 24.3% （9/37）,significantly lower than the 69.2% （9/13） in the control group （P 〈0.05）. The relative expression level of AQP8 in MC group was 0.639±0.160, lower than 0.921±0.148 of controls （P 〈0.05）. Global gene expression analysis showed that AQP8 mRNA expression was downregulated in MC patients.Conclusions The decreased AQP8 expression in MC patients indicates that chronic use of laxatives containing anthraquinone may cause reduced water absorption. The expression of AQP8 may be related to MC.展开更多
Background We analysed and compared the aquaporin 8 （AQP8） expression in ascending and descending colon mucosa between patients with diarrhoea-predominant irritable bowel syndrome （D-IBS） and healthy volunteers, i...Background We analysed and compared the aquaporin 8 （AQP8） expression in ascending and descending colon mucosa between patients with diarrhoea-predominant irritable bowel syndrome （D-IBS） and healthy volunteers, in order to study the relationship between the clinical feature of IBS, the expression of AQP8 and the pathological mechanism of D-IBS. Methods Specimens were taken from the proximal ascending colon or distal descending colon of D-IBS patients （n=-26） and healthy volunteers （n=30）, and AQP8 mRNA expression of each specimen was determined by fluorescent quantitative reverse transcription polymerase chain reaction （FQ-RT-PCR）. In patients with D-IBS, the relationship was analysed between AQP8 expression in both ascending and descending colons and clinical features including gender, age of onset, duration of illness, frequency of defecation, and stool characteristics. Results Although AQP8 was present in the epithelium of the ascending and descending colons in healthy persons and D-IBS patients, the AQP8 level of the D-IBS patients was significantly lower than that of the healthy persons （P〈0.01 in the ascending colon, P〈0.05 in the descending colon）. AQP8 expression was not correlated with the age of patients with D-IBS （P〉0.05 both in the ascending and descending colons） or the age at the onset （P〉0.05 both in the ascending and descending colons）, but closely with the duration of illness （P〈0.05 in the ascending colon, P〈0.01 in the descending colon）, frequency of defecation （P〈0.01 in the ascending colon, P〈0.05 in the descending colon） and stool characteristics （P〈0.01 in the ascending colon, P〉0.05 in the descending colon）. Conclusions The decreased AQP8 expression in D-IBS patients indicates that dysfunction of colonic absorption may cause reduced water absorption, loose stool and diarrhoea. The expression of AQP8 may be related to D-IBS.展开更多
Background Ulcerative colitis （UC） is associated with differential expression of genes involved in inflammation and tissue remodeling. MicroRNA （miRNA） plays an important role in the pathogenesis of UC by regulati...Background Ulcerative colitis （UC） is associated with differential expression of genes involved in inflammation and tissue remodeling. MicroRNA （miRNA） plays an important role in the pathogenesis of UC by regulating the gene expression at the post-transcriptional level and control crucial physiological processes. This study aimed to identify aquaporin 8 （AQP8） expression and its relationship with miRNA in UC patients. Methods Human colon samples, in this study, were obtained from 20 patients with UC and 16 healthy subjects undergoing diagnostic colonoscopy at the Chinese People＇s Liberation Army General Hospital between December 2009 and June 2010. We screened different genes from UC tissues and healthy subjects using genome-wide microarray, quantitative reverse transcription-polymerase chain reaction （qRT-PCR） and Western blotting. Regulation of gene expression by miRNAs was assessed by luciferase reporter construct assays and transfection of specific miRNA mimics and inhibitor. Results We identified that 1596 genes were increased and 1301 genes were decreased in UC patients compared to healthy subjects. Among them, we focused on the analysis of AQP8 which was decreased three folds in UC tissues （P 〈0.01）. The expression of AQP8 mRNA and protein were decreased in UC tissue and tumor necrosis factor （TNF）-α treated HT29 cells compared with controls （P 〈0.05）. We searched candidate target miRNAs of AQP8 through bioformatics and the luciferase report assay analysis indicated that miR-424, miR-195, miR-330, miR-612, and miR-16 which has complementary site in the 3-untranslated region （3＇UTR） of AQP8 could decrease the relative luciferase activities by 10%-45%. Conclusion AQP8 and its relationship with miRNAs may be involved in the pathogenesis of UC.展开更多
AIM: To study susceptibility genes which may play a potential role in the pathogenesis and etiology of inflammatory bowel disease (IBD). METHODS: To identify potential susceptibility genes we performed global gene exp...AIM: To study susceptibility genes which may play a potential role in the pathogenesis and etiology of inflammatory bowel disease (IBD). METHODS: To identify potential susceptibility genes we performed global gene expression profiling in patients with IBD and control specimens. For determination of an intrinsic gene expression profile in ulcerative colitis (UC) and Crohn’s disease (CD) compared to normal subjects, mucosal biopsies of non-inflamed regions of the colon and the terminal ileum were subjected to DNA microarray analysis. Real-time RT-PCR and immunohistochemistry were used for verification of selected regulated candidate genes and a genetic analysis was performed. RESULTS: We could show that aquaporin-8 (AQP8) mRNA and protein levels were significantly increased in the colon of UC patients compared to controls. Genetic analysis of the six exons and the promoter region of AQP8, however, revealed no mutations or polymorphisms in IBD patients. CONCLUSION: Our results suggest that upregulation of AQP8 in the colon of UC patients represents a secondary phenomenon which may, due to altered water exchange of the distal intestinal mucosa, disturb the physiologic colonic mucus barrier and thus lead to chronic infla- mmation and ulceration.展开更多
文摘Background: Aquaporins (AQPs), the family of water-selective channels, are localized in various organs and tissues, including the gastrointestinal (GI) tract. However, the roles of AQPs in the GI tract remain unclear. Materials and Methods: Male SD rats were subjected to subtotal colectomy (Group C, n = 22) or a sham operation (Group S, n = 16) and were sacri-ficed on postoperative days 7, 14, and 28. Total RNAs from the distal ileum and rectum were extracted. Quantitative RT-PCR was performed to measure AQP8 mRNA expression. For light-microscopy or immunohistochemistry, paraffin-embedded sections of 4 μm were prepared with H-E staining or anti-AQP8 antibody reaction. Mann-Whitney U-test was performed to compare the AQP8 distributions between the two groups, and the statistical significance was defined as
文摘Backgrounds: Aquaporins (AQPs), the mammalian water channels, have been localized in various organs, including the gastrointestinal (GI) tract. We examined AQPs expression in rat models of massive intestineal resection to determine the functions of AQPs in the GI tract. Methods: Female Sprague-Dawley rats (n = 15) underwent 90% resection of the small intestine, and Female Wistar-Kyoto rats (n = 10), received subtotal colectomy, and were sacrificed following the operations. RNase protection assay and quantitative reverse transcription-polymerase chain reaction (RT-PCR) were performed to measure the AQPs mRNA expression in the GI tract. Immunohistochemistry was performed to confirm AQP8 protein expression. Results: AQP8 mRNA expression (mean ± standard error), was enhanced in the jejunum of the short bowel rats at days 7 and 14 (37.6% ± 1.4% and 18.5% ± 2.4%, respectively, p < 0.01). Enhancement of AQP8 mRNA was also observed in the remnant rectum of the subtotal colectomized rats at both days 21 and 42 (116.1% ± 4.5% and 143.3% ± 7.4%, respectively, p < 0.01). Immunohistochemistry demonstrated enhanced AQP8 expression in the remnant rectum of the subtotal colectomized rats. No intensive change was observed with other AQPs in both models. Conclusions: Our results suggest a compensatory role of AQP8 in the maintenance of intestinal fluid balance.
文摘Background The relationship between melanosis coli （MC） and aquaporin 8 （AQP8） has not yet been elucidated. The aim of this research was to investigate the relationship between the expression of AQP8 and the pathological mechanism of MC.Methods Expression of AQP8 was detected by immunohistochemistry and reverse transcription-polymerase chain reaction （RT-PCR） in 37 MC colon tissues and 13 control colon tissues. Global gene expression analysis was also used to identify differently expressed genes. Its relationship with MC was analyzed by SPSS 11.5 statistical software.Results The positive rate of AQP8 expression detected by immunohistochemistry in the MC group was 24.3% （9/37）,significantly lower than the 69.2% （9/13） in the control group （P 〈0.05）. The relative expression level of AQP8 in MC group was 0.639±0.160, lower than 0.921±0.148 of controls （P 〈0.05）. Global gene expression analysis showed that AQP8 mRNA expression was downregulated in MC patients.Conclusions The decreased AQP8 expression in MC patients indicates that chronic use of laxatives containing anthraquinone may cause reduced water absorption. The expression of AQP8 may be related to MC.
文摘Background We analysed and compared the aquaporin 8 （AQP8） expression in ascending and descending colon mucosa between patients with diarrhoea-predominant irritable bowel syndrome （D-IBS） and healthy volunteers, in order to study the relationship between the clinical feature of IBS, the expression of AQP8 and the pathological mechanism of D-IBS. Methods Specimens were taken from the proximal ascending colon or distal descending colon of D-IBS patients （n=-26） and healthy volunteers （n=30）, and AQP8 mRNA expression of each specimen was determined by fluorescent quantitative reverse transcription polymerase chain reaction （FQ-RT-PCR）. In patients with D-IBS, the relationship was analysed between AQP8 expression in both ascending and descending colons and clinical features including gender, age of onset, duration of illness, frequency of defecation, and stool characteristics. Results Although AQP8 was present in the epithelium of the ascending and descending colons in healthy persons and D-IBS patients, the AQP8 level of the D-IBS patients was significantly lower than that of the healthy persons （P〈0.01 in the ascending colon, P〈0.05 in the descending colon）. AQP8 expression was not correlated with the age of patients with D-IBS （P〉0.05 both in the ascending and descending colons） or the age at the onset （P〉0.05 both in the ascending and descending colons）, but closely with the duration of illness （P〈0.05 in the ascending colon, P〈0.01 in the descending colon）, frequency of defecation （P〈0.01 in the ascending colon, P〈0.05 in the descending colon） and stool characteristics （P〈0.01 in the ascending colon, P〉0.05 in the descending colon）. Conclusions The decreased AQP8 expression in D-IBS patients indicates that dysfunction of colonic absorption may cause reduced water absorption, loose stool and diarrhoea. The expression of AQP8 may be related to D-IBS.
文摘Background Ulcerative colitis （UC） is associated with differential expression of genes involved in inflammation and tissue remodeling. MicroRNA （miRNA） plays an important role in the pathogenesis of UC by regulating the gene expression at the post-transcriptional level and control crucial physiological processes. This study aimed to identify aquaporin 8 （AQP8） expression and its relationship with miRNA in UC patients. Methods Human colon samples, in this study, were obtained from 20 patients with UC and 16 healthy subjects undergoing diagnostic colonoscopy at the Chinese People＇s Liberation Army General Hospital between December 2009 and June 2010. We screened different genes from UC tissues and healthy subjects using genome-wide microarray, quantitative reverse transcription-polymerase chain reaction （qRT-PCR） and Western blotting. Regulation of gene expression by miRNAs was assessed by luciferase reporter construct assays and transfection of specific miRNA mimics and inhibitor. Results We identified that 1596 genes were increased and 1301 genes were decreased in UC patients compared to healthy subjects. Among them, we focused on the analysis of AQP8 which was decreased three folds in UC tissues （P 〈0.01）. The expression of AQP8 mRNA and protein were decreased in UC tissue and tumor necrosis factor （TNF）-α treated HT29 cells compared with controls （P 〈0.05）. We searched candidate target miRNAs of AQP8 through bioformatics and the luciferase report assay analysis indicated that miR-424, miR-195, miR-330, miR-612, and miR-16 which has complementary site in the 3-untranslated region （3＇UTR） of AQP8 could decrease the relative luciferase activities by 10%-45%. Conclusion AQP8 and its relationship with miRNAs may be involved in the pathogenesis of UC.
文摘AIM: To study susceptibility genes which may play a potential role in the pathogenesis and etiology of inflammatory bowel disease (IBD). METHODS: To identify potential susceptibility genes we performed global gene expression profiling in patients with IBD and control specimens. For determination of an intrinsic gene expression profile in ulcerative colitis (UC) and Crohn’s disease (CD) compared to normal subjects, mucosal biopsies of non-inflamed regions of the colon and the terminal ileum were subjected to DNA microarray analysis. Real-time RT-PCR and immunohistochemistry were used for verification of selected regulated candidate genes and a genetic analysis was performed. RESULTS: We could show that aquaporin-8 (AQP8) mRNA and protein levels were significantly increased in the colon of UC patients compared to controls. Genetic analysis of the six exons and the promoter region of AQP8, however, revealed no mutations or polymorphisms in IBD patients. CONCLUSION: Our results suggest that upregulation of AQP8 in the colon of UC patients represents a secondary phenomenon which may, due to altered water exchange of the distal intestinal mucosa, disturb the physiologic colonic mucus barrier and thus lead to chronic infla- mmation and ulceration.
