OBJECTIVETo investigate the expressions of aquaporins (AQPs) in the mouse prostatic tissue and their significance, and to provide some evidence for a deeper insight into the physiological function and regulation of AQP expressions in normal and diseased prostatic tissues.

METHODSThe mRNA expressions of AQP0 - 4 in the mouse prostatic tissue were determined by RT-PCR, and the expressions and localizations of AQP1 and AQP3 proteins were characterized by Western blot and immunohistochemistry.

RESULTSRT-PCR exhibited the mRNA expressions of AQP1 and AQP3, but not those of AQP0, AQP2 and AQP4 in the prostate tissue, while Western blot showed the expression of the AQP1 protein with the relative molecular mass (RMM) of 28 000 and those of the glycosylated and non-glycosylated AQP3 proteins with the RMM of 35 000 and 27 000, respectively. Immunohistochemistry indicated the strong expression of AQP1 in the cyst and plasma membrane of the secretary cells and that of AQP3 in the stroma cells of the prostate.

CONCLUSIONThe AQP1 and AQP3 genes were expressed in the secretary epithelia of the mouse prostate tissue, which suggests that AQP1 and AQP3 may play an important role in the secretion of prostatic fluid.

Animals ; Aquaporin 1 ; genetics ; metabolism ; Aquaporin 3 ; genetics ; metabolism ; Male ; Mice ; Mice, Inbred BALB C ; Prostate ; metabolism ; pathology

To evaluate the effect of dexamethasone on the expression of aquaporin-1 (AQP-1) in cultured bovine trabecular meshwork cells, bovine trabecular meshwork cells were cultured in vitro and reproduced to the third and the fourth generation, then treated with dexamethasone at the concentrations of 5, 25, 50, 250 microg/L respectively for 7 days. Immunohistochemical technique-supervision method was employed to measure, and image analysis system to analyze the expression of AQP-1 in normal cultured bovine trabecular meshwork cells and those treated with dexamethasone. In normal bovine trabecular meshwork cells, the grayscale of AQP-1 positive staining was 167.94 +/- 1.18, while it was 168.92 +/- 0.91, 176.72 +/- 1.80, 180.64 +/- 1.31, 185.64 +/- 1.58 in cells treated with 5, 25, 50, 250 microg/L concentrations of dexamethasone. When the concentration of dexamethasone was higher than 25 microg/L, the expression of AQP-1 was significantly inhibited (P < 0.05). The regulation of AQP-1 expression by dexamethasone in cultured bovine trabecular meshwork cells in vitro may be one of causes that retard the aqueous outflow in glucocorticoid- induced glaucoma.
Aquaporin 1/*biosynthesis ; Aquaporin 1/genetics ; Cells, Cultured ; Depression, Chemical ; Dexamethasone/*pharmacology ; Dose-Response Relationship, Drug ; Immunohistochemistry ; Trabecular Meshwork/cytology ; Trabecular Meshwork/*metabolism

OBJECTIVETo investigate the changes in the myocardial expression of aquaporin-1 (AQP1) protein and its association with myocardial edema in rats with severe burns.

METHODSForty-eight healthy adult Wistar rats were randomly divided into normal control group (n=6) and burn injury group with third degree burn of 30% total body surface area, and the latter group was further divided into 2, 4, 8, 12, 24, 48 and 72 h groups. The changes of myocardial water content were investigated by dry-wet weight methods. Enzyme-linked immunosorbent assay was used to detect the changes in AQP1 expression at different time points after sever burns.

RESULTSThe myocardial water content and AQP1 expression increased significantly 2 h after the burn injury, reaching the peak levels at 12 h and remaining higher than the normal level at 48 h. A significant positive correlation was found between myocardial water content and AQP1 expression in the rats (r=0.868, P<0.01).

CONCLUSIONThe severity of myocardial edema after severe burn is correlated to the expression level of AQPl protein, suggesting the important role of AQPl protein in pathological progression of myocardial edema.

Animals ; Aquaporin 1 ; genetics ; metabolism ; Burns ; metabolism ; pathology ; Edema ; metabolism ; Female ; Male ; Myocardium ; metabolism ; pathology ; Random Allocation ; Rats ; Rats, Wistar

OBJECTIVETo explore the changes of vascular endothelial growth factor(VEGF), aquaporin (AQP) gene and protein expression during hypoxic encephaledema so as to provide the basis for elucidating the brain injury caused by acute hypoxic exposure and pathogenesis of the encephaledema.

METHODSWistar rats were randomly divided into 4 groups, i.e. control group, hypoxia 4 000 m group, hypoxia 6 000 m group and hypoxia 8 000 m group. Rats in hypoxic groups were exposed to hypoxia at simulated altitude of 4 000 m, 6 000 m and 8 000 m above sea level for 8 hours respectively in order to establish hypoxic encephaledema model. The water content in brain was determined by dry-weight method. The changes in morphology of brains were observed under optical microscope. The changes in expression of VEGF, AQP1 and AQP4 genes and protein were determined by RT-PCR and immunohistochemistry.

RESULTS(1) The results determined by dry-weight method indicated that water content of rats brain increased markedly after rats were exposed to a simulated altitude at 6 000 m, 8 000 m. (2) The results determined by microscopy indicated that during the rats exposed to hypoxia, nerve cells, vascular endothelial cells and astrocyte foot processes swelled lightly, transudate occurred in tissues at 4 000 m. The swelling of vascular endothelial cell (VEC) and astrocyte foot processes aggravated, interspace between vessels and tissues enlarged, and transudate in tissue increased at 6 000 m. The swelling of VEC and astrocyte foot processes went from bad to worse, interspace between vessels and tissues enlarged further, and transudate in tissue increased evidently at 8 000 m. (3) During hypoxic encephaledema, the expression of VEGF, AQP1 and AQP4 mRNA increased, AQP1 was abnormally expressed on the surface of VEC, and the expressive level of VEGF and AQP1 on VEC and AQP4 on astrocyte foot processes increased.

CONCLUSIONThe changes in expression and distribution of VEGF, AQP1 and AQP4 during encephaledema caused by hypoxic exposure may induce blood-brain barrier injury, and may be one of the pathogenesis of hypoxic encephaledema.

Animals ; Aquaporin 1 ; genetics ; metabolism ; Aquaporin 4 ; genetics ; metabolism ; Blood-Brain Barrier ; pathology ; Brain ; metabolism ; Brain Edema ; etiology ; metabolism ; physiopathology ; Hypoxia ; complications ; metabolism ; Male ; RNA, Messenger ; genetics ; metabolism ; Rats ; Rats, Wistar ; Vascular Endothelial Growth Factor A ; genetics ; metabolism

OBJECTIVETo investigate the expression of aquaporin (AQP)-1, 3, 8, 9 in human fetal membrane and their role in the human amniotic fluid circulation.

METHODSRT-PCR was employed for detection of the expressions of AQP-1, 3, 8, 9 mRNA in human amnion and chorion from 20 women with normal term pregnancy.

RESULTSAQP-1, 3, 8, 9 mRNA expression was detected in both human amnion and chorion, and no significant difference was found in their expression levels or between the amnion and chorion (P>0.05).

CONCLUSIONAQP-1, 3, 8, 9 can be associated with intramembranous transport and volume regulation of amniotic fluid.

Adult ; Amnion ; embryology ; metabolism ; Aquaporin 1 ; genetics ; Aquaporin 3 ; genetics ; Aquaporins ; genetics ; Chorion ; embryology ; metabolism ; Electrophoresis, Agar Gel ; Extraembryonic Membranes ; embryology ; metabolism ; Female ; Gene Expression Regulation, Developmental ; Humans ; Pregnancy ; Reverse Transcriptase Polymerase Chain Reaction

OBJECTIVETo investigate the expression of aquaporin 1 (AQP1) in endometrium of patients with menorrhagia.

METHODSRT-PCR and immunohistochemistry were carried out in twenty women with normal menstrual cycle to confirm the expression of AQP1 in endometrium and locate it. Then 51 women with menorrhagia and 40 women with normal menstrual cycle were included in the study. RT-PCR and immunohistochemistry were used to examine the expression of AQP1.

RESULTAQP1 mRNA was expressed in the human endometrium throughout menstruation cycle, which was mainly located in the endothelia of the capillaries and small blood vessels. Quantification of the immunostaining revealed higher density during secretary phase than that in proliferative phase (P<0.01). The staining intensity and density of AQP1-positive microvessel decreased significantly in simple hyperplasia group (P<0.01) and then gradually increased in complex hyperplasia and atypical hyperplasia groups (P<0.001).

CONCLUSIONDecreased expression of AQP1 may lead to disturbed endometrial vascular remodeling and may be involved in the occurrence of menorrhagia.

Adult ; Aquaporin 1 ; biosynthesis ; genetics ; Endometrium ; blood supply ; metabolism ; Female ; Gene Expression ; Humans ; Immunohistochemistry ; Menorrhagia ; genetics ; metabolism ; pathology ; RNA, Messenger ; biosynthesis ; genetics ; Reverse Transcriptase Polymerase Chain Reaction

Animals ; Aquaporin 1 ; analysis ; genetics ; physiology ; Aquaporin 3 ; analysis ; genetics ; physiology ; Disease Models, Animal ; Immunohistochemistry ; Lung ; blood supply ; metabolism ; RNA, Messenger ; analysis ; Rats ; Rats, Wistar ; Reperfusion Injury ; etiology ; metabolism

BACKGROUNDOver 70% of the total tissue weight in the cartilage matrix consists of water, and the early-stage osteoarthritic cartilage is characterized by swelling. Water transport in the cartilage matrix and across the membranes of chondrocytes may be important in normal and pathological conditions of cartilage. The purpose of this study was to identify aquaporin-1 (AQP1) and aquaporin-3 (AQP3) expressions in the mandibular condylar cartilage after experimentally induced osteoarthritis (OA) in rats.

METHODSAn experimental temporomandibular joint OA was induced by partial discectomy in rats. The pathological characteristics of the normal, early-stage, and late-stage osteoarthritic TMJ cartilages were verified by histological techniques. The AQP1 and AQP3 gene expressions in the normal and osteoarthritic cartilages were measured using quantitative real-time reverse-transcription PCR analysis. The cartilage sections were incubated in primary polyclonal antibodies to AQP3; immunofluorescent microscopy was used to examine the AQP3 expression shown by its protein level.

RESULTSThe mRNA expression levels of AQP1 and AQP3, analyzed using quantitative PCR, revealed that AQP3 mRNA was highly up-regulated in the OA cartilage, which was considered significant. There was no notable difference in the expression of AQP1 mRNA between OA and normal controls. With the progressing of the OA, the localization of the AQP3 protein was quite different from that of the normal cartilage. Compared to the normal cartilage, the expressions of AQP3 protein were observed mainly in the proliferative zone and the upper mid-zone chondrocytes at the early-stage of OA, and were observed to appear frequently throughout the mid- and deep zone during the late-stage of OA.

CONCLUSIONSThe high expression of AQP3 mRNA in the OA cartilage and the different localization of the AQP3 protein suggest that it may play a particular role in OA pathogenesis. Further study of AQP3 function may provide new insight into the understanding of the molecular mechanisms underlying OA.

Animals ; Aquaporin 1 ; genetics ; Aquaporin 3 ; genetics ; Cartilage, Articular ; metabolism ; Male ; Microscopy, Fluorescence ; Osteoarthritis ; metabolism ; RNA, Messenger ; analysis ; Rats ; Rats, Wistar ; Reverse Transcriptase Polymerase Chain Reaction ; Temporomandibular Joint ; metabolism

OBJECTIVETo explore the role of aquaporin-1 (AQP1) gene in erythroid differentiation of erythroleukemia K562 cells induced by retinoic acid (RA).

METHODSK562 cells were cultured in the presence of 1 µmol/L RA for varying lengths of time, and γ-globin mRNA expression and hemoglobin content in the cells were detected by real-time PCR (RT-PCR) and ultraviolet spectrophotometry, respectively, to evaluate the erythroid differentiation of K562 cells. RT-PCR and Western blotting were used to examine AQP1 expression in the cells following RA treatment. A retroviral expression vector of AQP1 small interfering RNA (pSUPER-retro-puro-shAQP1) was constructed and transfected into K562 cells to establish a K562 cell line with stable AQP1 down-regulation (K562-shAQP1), in which the changes in γ-globin and hemoglobin expressions after RA treatment were detected.

RESULTSRA treatment significantly increased γ-globin and hemoglobin expressions in K562 cells (P<0.01), causing also significantly enhanced AQP1 mRNA and protein expressions over time (P<0.01). Transfection with the recombinant plasmids pSuper-retro-puro-shAQP1 resulted in stable AQP1 suppression in K562 cells (P<0.01), which showed markedly reduced γ-globin and hemoglobin expressions after RA induction as compared to the control K562 cells (P<0.01).

CONCLUSIONK562 cells show a significant increase of AQP1 expression after RA-induced erythroid differentiation, and suppression of AQP1 expression can partially block the effect of RA, suggesting the important role of AQP1 in RA-induced erythroid differentiation of K562 cells.

Aquaporin 1 ; antagonists & inhibitors ; metabolism ; Cell Differentiation ; drug effects ; Humans ; K562 Cells ; Leukemia, Erythroblastic, Acute ; metabolism ; RNA, Messenger ; genetics ; RNA, Small Interfering ; genetics ; Tretinoin ; pharmacology

The objective of this study was to establish an RNAi approach that can specifically target aqp1 gene sequence in vitro, and to assess the inhibitory effect of this siRNA on K562 cells. The siRNA targeting aqp1-mRNA was designed and transfected into K562 cells by using Lipofectamine(TM) 2000 reagent. Phase-contrast microscopy was used to analyze morphology changes of K562 cells. Cell viability was determined by MTT assay, and flow cytometry and DNA ladder analysis were carried out to identify siRNA-induced apoptosis. The expression levels of aqp1-mRNA at different transfection time were detected by RT-PCR. The results showed that the siRNA was successful by established. The transfected K562 cells displayed the significant apoptosis. The aqp1-siRNAs could obviously inhibit the activity of K562 cells. Cellular DNA fragmentation was observed in the siRNA group after transfection for 48 hours, the apoptosis rates at 24, 48 and 72 hours after transfection were 24.2%, 36.1% and 42.9% respectively. The aqp1-mRNA expression in the cells treated by aqp1-siRNA for 24, 48 and 72 hours were significantly reduced by 33%, 46% and 57% respectively. It is concluded that the aqp1-siRNA can efficiently and specifically inhibited the proliferation and inducing apoptosis of K562 cells. Gene aqp1 can be a potential target point for therapy of malignant tumor.
Apoptosis ; drug effects ; Aquaporin 1 ; genetics ; Cell Proliferation ; drug effects ; Cell Survival ; drug effects ; Gene Targeting ; Humans ; K562 Cells ; RNA Interference ; RNA, Small Interfering ; genetics ; pharmacology