In this study,the effects of hyperosmolality on the expression of urea transporter A2 (UTA2) and aquaporin 2 (AQP2) were investigated in transfected immortalized mouse medullary collecting duct (mIMCD3) cell line.AQP2...In this study,the effects of hyperosmolality on the expression of urea transporter A2 (UTA2) and aquaporin 2 (AQP2) were investigated in transfected immortalized mouse medullary collecting duct (mIMCD3) cell line.AQP2-GFP-pCMV6 and UTA2-GFP-pCMV6 plasmids were stably transfected into mIMCD3 cells respectively.Transfected mIMCD3 and control cells were cultured in different hy-pertonic media,which were made by NaCl alone,urea alone,or an equiosmolar mixture of NaCl and urea.The mRNA and protein expression of AQP2 was elevated by the stimulation of NaCl alone,urea alone and NaCl plus urea in AQP2-mIMCD3 cells;whereas NaCl alone and NaCl plus urea rather than urea alone increased the mRNA and protein expression of UTA2 in UTA2-mIMCD3 cells,and all the expression presented an osmolality-dependent manner.Moreover,the mRNA and protein expression of UTA2 rather than AQP2 was found to be synergistically up-regulated by a combination of NaCl and urea in mIMCD3 cells.It is concluded that NaCl and urea synergistically induce the expression of UTA2 rather than AQP2 in mIMCD3 cells,and hyperosmolality probably mediates the expression of AQP2 and UTA2 through different mechanisms.展开更多
OBJECTIVE: To investigate the effect of Sanao Tang(SAT) on urine volume and the expression of aquaporin-2(AQP2) in rats with lung dysfunction induced by passive smoking and lipopolysaccharide.METHODS: Totally 45 healt...OBJECTIVE: To investigate the effect of Sanao Tang(SAT) on urine volume and the expression of aquaporin-2(AQP2) in rats with lung dysfunction induced by passive smoking and lipopolysaccharide.METHODS: Totally 45 healthy Specific pathogen Free Wistar Rats were randomized into 3 groups:normal control group, model group and SAT group.A rat model of respiratory dysfunction induced by exposure to cigarette smoking and lipopolysaccharide(LPS). Lavage of decoction of the Chinese medicine was performed for rats in the SAT group. Anires 2005 System was used to analyze the pulmonary function. Urine of rats was collected through metabolism cage method. Enzyme-linked immunosorbent assay(ELISA) was used to determine content of antidiuretic hormone(ADH), angiotensin Ⅱ(AngⅡ), atrial natriuretic factor(ANP), endothelin 1(ET-1), nitric oxide(NO) and prostaglandin E2(PGE2) in serum, lung and kidney. The expression of AQP2 in rat renal tissue was determined with real-time fluorescence quantitative PCR(RT-PCR).RESULTS:(a) In comparison with the normal control, It was found that enforced vital capacity(FVC),1-second forced expiratory volume/forced vital capacity%(FEV1/FVC%), 24 h urine volume content of NO and PGE2 were decreased, while AQP2 m RNA level and content of ADH, Agn Ⅱ, ANP and ET-1were increased in the model group with statistical significance(P < 0.05).(b) In comparison with the model group, It was found that FVC, FEV1, FEV1/FVC%, 24 h urine volume, content of PGE2 and NO decreased, while AQP2 m RNA level, content of ANP,ADH and AngⅡ decreased in the SAT group with statistical significance(P < 0.05).CONCLUSION: SAT might effectively regulate the urine volume in the modeled rats; ADH, Ang Ⅱ,ANP, ET-1, NO and PGE2 might play an important role in the regulation on urine volume by lungs.This might be the mechanisms underpinning the function of lung governing water passage in terms of the theory of Traditional Chinese Medicine.展开更多
In current study, the effect of angiotensin receptor blocker Micardis on the localization and expression of aquaporin-2 （AQP2） was investigated in the renal medullary collecting duct of mice with diabetic nephropat...In current study, the effect of angiotensin receptor blocker Micardis on the localization and expression of aquaporin-2 （AQP2） was investigated in the renal medullary collecting duct of mice with diabetic nephropathy （DN）. Mice were divided into three groups： normal group, DN group and Micardis-treated group. Six weeks after establishment of STZ-induced DN model in mice, the expression of AQP2 in renal medulla was detected measured by semiquantitative immunofluorescence histochemistry and Western blot techniques, and the localization of AQP2 by confocal immunofluorescence laser scanning microscopy. The results showed that the urinary osmolality was decreased in DN group as compared with normal group （2.39±0.11 vs 3.16±0.16, P〈0.05）. Although the localization of AQP2 on the renal medulla was unchanged, the expression of AQP2 was increased significantly in DN group as compared with normal group. Micardis could partly attenuate above changes. It was concluded that treatment with Micardis could partly rectify the abnormal expression of AQP2 in renal medulla of DN mice, which suggested that rennin-angiotensin system （RAS） is implicated in the pathogenesis of DN by regulating the expression of AQP2.展开更多
AIM: To investigate the role of tolvaptan in regulating aquaporin(AQP)-2 expression and fecal water content in cirrhotic rats with ascites.METHODS: Cirrhosis with ascites was induced in rats by repetitive dorsal injec...AIM: To investigate the role of tolvaptan in regulating aquaporin(AQP)-2 expression and fecal water content in cirrhotic rats with ascites.METHODS: Cirrhosis with ascites was induced in rats by repetitive dorsal injection of CCl4 for 14 wk. In total, 84 cirrhotic rats with ascites divided into three groups(vehicle, 3 mg/kg and 5 mg/kg tolvaptan), and then further divided into five subgroups(days 1, 2, 3, 4, and 5). Blood samples were obtained to measure vasopressin and sodium concentrations. Rats were killed and colonic mucosa was scraped for analysis of protein expression and AQP-2 transcriptional level. The whole layer was fixed for hematoxylin&eosin(HE) staining and feces were collected for determination of fecal water content. CONCLUSION: Compared with vehicle, vasopressin decreased significantly in the tolvaptan groups from day 2 to a similar level in each treatment group. AQP-2 showed significant upregulation in cirrhotic rats with ascites compared with an untreated control group(100% ± 22.9% vs 22.2% ± 10.23%, P < 0.01). After administration of tolvaptan, AQP-2 expression began to decrease significantly from day 2 in each treatment group, but no significant difference was finally found between the treatment groups. Fecal water content inthe distal colon was increased by 5 mg/kg tolvaptan on day 1(66.8% ± 9.3% vs 41.4% ± 6.3%, in the vehicle group, P < 0.05). Fecal water content returned to baseline at day 4 at the latest in both treatment groups, and did not correspond to the change in AQP-2 expression. HE staining of the colonic mucosa showed no mucosal damage related to tolvaptan.CONCLUSION: Upregulation of AQP-2 in the distal colon is found in cirrhotic rats with ascites. Tolvaptan inhibits its expression and may decrease water reabsorption and induce diarrhea.展开更多
Objective To investigate the role of extracellular signal-regulated kinase1/2（ERK1/2） pathway in the regulation of aquaporin 4（AQP4） expression in cultured astrocytes after scratch-injury. Methods The scratch-inju...Objective To investigate the role of extracellular signal-regulated kinase1/2（ERK1/2） pathway in the regulation of aquaporin 4（AQP4） expression in cultured astrocytes after scratch-injury. Methods The scratch-injury model was produced in cultured astrocytes of rat by a 10-μL plastic pipette tip. The morphological changes of astrocytes and lactate dehydrogenase（LDH） leakages were observed to assess the degree of scratch-injury. AQP4 expression was detected by immunofluorescence staining and Western blot, and phosphorylated-ERK1/2（p-ERK1/2） expression was determined by Western blot. To explore the effect of ERK1/2 pathway on AQP4 expression in scratch-injured astrocytes, 10 μmol/L U0126（ERK1/2 inhibitor） was incubated in the medium at 30 min before the scratch-injury in some groups. Results Increases in LDH leakage were observed at 1, 12, and 24 h after scratch-injury, and AQP4 expression was reduced simultaneously. Decrease in AQP4 expression was associated with a significant increase in ERK1/2 activation. Furthermore, pretreatment with U0126 blocked both ERK1/2 activation and decrease in AQP4 expression induced by scratch-injury. Conclusion These results indicate that ERK1/2 pathway down-regulates AQP4 expression in scratch-injured astrocytes, and ERK1/2 pathway might be a novel therapeutic target in reversing the effects of astrocytes that contribute to traumatic brain edema.展开更多
基金supported by a grant from National Natural Science foundation of China (No. 30871173)
文摘In this study,the effects of hyperosmolality on the expression of urea transporter A2 (UTA2) and aquaporin 2 (AQP2) were investigated in transfected immortalized mouse medullary collecting duct (mIMCD3) cell line.AQP2-GFP-pCMV6 and UTA2-GFP-pCMV6 plasmids were stably transfected into mIMCD3 cells respectively.Transfected mIMCD3 and control cells were cultured in different hy-pertonic media,which were made by NaCl alone,urea alone,or an equiosmolar mixture of NaCl and urea.The mRNA and protein expression of AQP2 was elevated by the stimulation of NaCl alone,urea alone and NaCl plus urea in AQP2-mIMCD3 cells;whereas NaCl alone and NaCl plus urea rather than urea alone increased the mRNA and protein expression of UTA2 in UTA2-mIMCD3 cells,and all the expression presented an osmolality-dependent manner.Moreover,the mRNA and protein expression of UTA2 rather than AQP2 was found to be synergistically up-regulated by a combination of NaCl and urea in mIMCD3 cells.It is concluded that NaCl and urea synergistically induce the expression of UTA2 rather than AQP2 in mIMCD3 cells,and hyperosmolality probably mediates the expression of AQP2 and UTA2 through different mechanisms.
基金Supported by National Nature Science Fund Projects(the Influence of Lung"Governing Qi"on"Governing Water Passage"and Exploring Related Molecular Signaling Pathways,No.81373503)
文摘OBJECTIVE: To investigate the effect of Sanao Tang(SAT) on urine volume and the expression of aquaporin-2(AQP2) in rats with lung dysfunction induced by passive smoking and lipopolysaccharide.METHODS: Totally 45 healthy Specific pathogen Free Wistar Rats were randomized into 3 groups:normal control group, model group and SAT group.A rat model of respiratory dysfunction induced by exposure to cigarette smoking and lipopolysaccharide(LPS). Lavage of decoction of the Chinese medicine was performed for rats in the SAT group. Anires 2005 System was used to analyze the pulmonary function. Urine of rats was collected through metabolism cage method. Enzyme-linked immunosorbent assay(ELISA) was used to determine content of antidiuretic hormone(ADH), angiotensin Ⅱ(AngⅡ), atrial natriuretic factor(ANP), endothelin 1(ET-1), nitric oxide(NO) and prostaglandin E2(PGE2) in serum, lung and kidney. The expression of AQP2 in rat renal tissue was determined with real-time fluorescence quantitative PCR(RT-PCR).RESULTS:(a) In comparison with the normal control, It was found that enforced vital capacity(FVC),1-second forced expiratory volume/forced vital capacity%(FEV1/FVC%), 24 h urine volume content of NO and PGE2 were decreased, while AQP2 m RNA level and content of ADH, Agn Ⅱ, ANP and ET-1were increased in the model group with statistical significance(P < 0.05).(b) In comparison with the model group, It was found that FVC, FEV1, FEV1/FVC%, 24 h urine volume, content of PGE2 and NO decreased, while AQP2 m RNA level, content of ANP,ADH and AngⅡ decreased in the SAT group with statistical significance(P < 0.05).CONCLUSION: SAT might effectively regulate the urine volume in the modeled rats; ADH, Ang Ⅱ,ANP, ET-1, NO and PGE2 might play an important role in the regulation on urine volume by lungs.This might be the mechanisms underpinning the function of lung governing water passage in terms of the theory of Traditional Chinese Medicine.
基金the Scientific Research Foundation for the Returned Overseas Chinese Scholars,Ministry of Education of China (Grant No. 2007-1108)
文摘In current study, the effect of angiotensin receptor blocker Micardis on the localization and expression of aquaporin-2 （AQP2） was investigated in the renal medullary collecting duct of mice with diabetic nephropathy （DN）. Mice were divided into three groups： normal group, DN group and Micardis-treated group. Six weeks after establishment of STZ-induced DN model in mice, the expression of AQP2 in renal medulla was detected measured by semiquantitative immunofluorescence histochemistry and Western blot techniques, and the localization of AQP2 by confocal immunofluorescence laser scanning microscopy. The results showed that the urinary osmolality was decreased in DN group as compared with normal group （2.39±0.11 vs 3.16±0.16, P〈0.05）. Although the localization of AQP2 on the renal medulla was unchanged, the expression of AQP2 was increased significantly in DN group as compared with normal group. Micardis could partly attenuate above changes. It was concluded that treatment with Micardis could partly rectify the abnormal expression of AQP2 in renal medulla of DN mice, which suggested that rennin-angiotensin system （RAS） is implicated in the pathogenesis of DN by regulating the expression of AQP2.
文摘AIM: To investigate the role of tolvaptan in regulating aquaporin(AQP)-2 expression and fecal water content in cirrhotic rats with ascites.METHODS: Cirrhosis with ascites was induced in rats by repetitive dorsal injection of CCl4 for 14 wk. In total, 84 cirrhotic rats with ascites divided into three groups(vehicle, 3 mg/kg and 5 mg/kg tolvaptan), and then further divided into five subgroups(days 1, 2, 3, 4, and 5). Blood samples were obtained to measure vasopressin and sodium concentrations. Rats were killed and colonic mucosa was scraped for analysis of protein expression and AQP-2 transcriptional level. The whole layer was fixed for hematoxylin&eosin(HE) staining and feces were collected for determination of fecal water content. CONCLUSION: Compared with vehicle, vasopressin decreased significantly in the tolvaptan groups from day 2 to a similar level in each treatment group. AQP-2 showed significant upregulation in cirrhotic rats with ascites compared with an untreated control group(100% ± 22.9% vs 22.2% ± 10.23%, P < 0.01). After administration of tolvaptan, AQP-2 expression began to decrease significantly from day 2 in each treatment group, but no significant difference was finally found between the treatment groups. Fecal water content inthe distal colon was increased by 5 mg/kg tolvaptan on day 1(66.8% ± 9.3% vs 41.4% ± 6.3%, in the vehicle group, P < 0.05). Fecal water content returned to baseline at day 4 at the latest in both treatment groups, and did not correspond to the change in AQP-2 expression. HE staining of the colonic mucosa showed no mucosal damage related to tolvaptan.CONCLUSION: Upregulation of AQP-2 in the distal colon is found in cirrhotic rats with ascites. Tolvaptan inhibits its expression and may decrease water reabsorption and induce diarrhea.
基金supported by the National Natural Science Foundation of China,No.81271286 to YUAN Fang and No.81228009 to YANG Shao Hua
文摘Objective To investigate the role of extracellular signal-regulated kinase1/2（ERK1/2） pathway in the regulation of aquaporin 4（AQP4） expression in cultured astrocytes after scratch-injury. Methods The scratch-injury model was produced in cultured astrocytes of rat by a 10-μL plastic pipette tip. The morphological changes of astrocytes and lactate dehydrogenase（LDH） leakages were observed to assess the degree of scratch-injury. AQP4 expression was detected by immunofluorescence staining and Western blot, and phosphorylated-ERK1/2（p-ERK1/2） expression was determined by Western blot. To explore the effect of ERK1/2 pathway on AQP4 expression in scratch-injured astrocytes, 10 μmol/L U0126（ERK1/2 inhibitor） was incubated in the medium at 30 min before the scratch-injury in some groups. Results Increases in LDH leakage were observed at 1, 12, and 24 h after scratch-injury, and AQP4 expression was reduced simultaneously. Decrease in AQP4 expression was associated with a significant increase in ERK1/2 activation. Furthermore, pretreatment with U0126 blocked both ERK1/2 activation and decrease in AQP4 expression induced by scratch-injury. Conclusion These results indicate that ERK1/2 pathway down-regulates AQP4 expression in scratch-injured astrocytes, and ERK1/2 pathway might be a novel therapeutic target in reversing the effects of astrocytes that contribute to traumatic brain edema.
