Loss of Caveolin 1 is Associated With the Expression of Aquaporin 1 and Bladder Dysfunction in Mice.

PURPOSE: It is suggested that caveolin and aquaporin might be closely associated with bladder signal activity. We investigated the effect of the deletion of caveolin 1, using caveolin 1 knockout mice, on the expression of aquaporin 1 in order to identify their relation in the urothelium of the urinary bladder. METHODS: The cellular localization and expressions of aquaporin 1 and caveolin 1, in the wild type and caveolin 1 knockout mice urinary bladder, were examined by Western blot and immunofluorescence techniques. RESULTS: Aquaporin 1 and caveolin 1 were coexpressed in the arterioles, venules, and capillaries of the suburothelial layer in the wild type controls. Aquaporin 1 protein expression was significantly higher in the caveolin 1 knockout mice than in the wild type controls (P <0.05). CONCLUSIONS: The results imply that aquaporin 1 and caveolin 1 may share a distinct relation with the bladder signal activity. This might play a specific role in bladder dysfunction.

Altered expression of caveolin 2 and 3 in smooth muscle of rat urinary bladder by 17ß-estradiol.

BACKGROUND: The purpose of this study was to investigate the effect of estrogen alteration on the expression of caveolin 2 and 3 in rat smooth muscle of urinary bladder. METHODS: Female Sprague-Dawley rats were divided into three groups: control, bilateral ovariectomy (Ovx), and bilateral ovariectomy followed by subcutaneous injections of 17ß-estradiol (Ovx+Est). After 4 weeks, urodynamic measurements were taken to ascertain the contraction interval and contraction pressure. The expression and cellular localization of caveolin 2 and 3 were determined by Western blot and immunohistochemistry in rat urinary bladder smooth muscle. RESULTS: In cystometrograms, the contraction interval (min) was significantly lower in the Ovx group (3.1±1.5) than in the control group (5.6±1.2), but was increased after estrogen treatment (9.3±1.0). Conversely, the average contraction pressure (mmHg) was higher in the Ovx group (26.2±2.3) than in the control group (21.9±3.1), and was decreased after estrogen treatment (23.8±3.5). Caveolin 2 and 3 expression was localized in the cell membrane of the smooth muscle. The protein expression of both caveolin 2 and 3 was significantly lower after ovariectomy and was restored to the control levels after 17ß-estradiol treatment. CONCLUSIONS: Hormonal alteration causes a significant change in the expression of caveolin 2 and 3 in smooth muscle of rat urinary bladder. These findings suggest that these molecules might have functional roles in the detrusor overactivity that occurs in association with hormonal alteration.

Effect of detrusor overactivity on the expression of aquaporins and nitric oxide synthase in rat urinary bladder following bladder outlet obstruction.

BACKGROUND: Aquaporins (AQPs) have recently been reported to be expressed in rat and human urothelium. Nitric oxide (NO) is thought to play a role in the bladder overactivity related to bladder outlet obstruction (BOO). The purpose of this study is to investigate the effect of BOO on the expression of AQP2-3 and nitric oxide synthase (NOS) isoforms in rat urothelium. METHODS: Female Sprague-Dawley rats (230-240 g, n = 60) were divided into 2 groups. The control group (n = 30) and the partial bladder outlet obstruction (BOO) group (n = 30). After 4 weeks, we performed a urodynamic study to measure the contraction interval and contraction pressure. The expression and cellular localization of AQP2-3, endothelial nitric oxide synthase (eNOS) and neuronal nitric oxide synthase (nNOS) were determined by Western blot and immunohistochemistry. RESULTS: On the cystometrogram, the estimated contraction interval time (minutes, mean ± SE) was significantly lower in the BOO group (3.0 ± 0.9) than in the control group (6.3 ± 0.4; p < 0.05). AQP2 was localized in the cytoplasm of the epithelium, whereas AQP3 was found only in the cell membrane of the epithelium. The protein expression of AQP2-3, eNOS and nNOS was significantly increased in the BOO group. CONCLUSION: Detrusor overactivity induced by BOO causes a significant increase in the expression of AQP2-3, eNOS, and nNOS in rat urinary bladder. This may imply that the AQPs and NOS isoforms have a functional role in the bladder dysfunction that occurs in association with BOO.

Overexpression of aquaporin-1 and caveolin-1 in the rat urinary bladder urothelium following bladder outlet obstruction.

PURPOSE: This study was designed to investigate the effect of detrusor overactivity induced by partial bladder outlet obstruction (BOO) on the expression of aquaporin 1 (AQP1) and caveolin 1 (CAV1) in the rat urinary bladder, and to determine the role of these molecules in detrusor overactivity. METHODS: Female Sprague-Dawley rats were divided into control (n=30) and experimental (n=30) groups. The BOO group underwent partial BOO, and the control group underwent a sham operation. After 4 weeks, an urodynamic study was performed to measure the contraction interval and contraction pressure. The expression and cellular localization of AQP1 and CAV1 were determined by western blot and immunofluorescence experiments in the rat urinary bladder. RESULTS: In cystometrograms, the contraction interval was significantly lower in the BOO group (2.9±1.5 minutes) than in the control group (6.7±1.0 minutes) (P<0.05). Conversely, the average contraction pressure was significantly higher in the BOO group (21.2±3.3 mmHg) than in the control group (13.0±2.5 mmHg) (P<0.05). AQP1 and CAV1 were coexpressed in the capillaries, arterioles, and venules of the suburothelial layer. AQP1 and CAV1 protein expression was significantly increased in the BOO rats compared to the control rats (P<0.05). CONCLUSIONS: Detrusor overactivity induced by BOO causes a significant increase in the expression of AQP1 and CAV1, which were coexpressed in the suburothelial microvasculature. This finding suggests that AQP1 and CAV1 might be closely related to bladder signal activity and may have a functional role in BOO-associated detrusor overactivity.

Changes in aquaporin (AQP)2 and AQP3 expression in ovariectomized rat urinary bladder: potential implication of water permeability in urinary bladder.

PURPOSE: AQPs have recently been reported to be expressed in rat and human urothelium. The purpose of this study was to investigate the effect of ovariectomy on the expression of AQP2 and AQP3 in rat urothelium. MATERIALS AND METHODS: Female Sprague-Dawley rats were divided into three groups: control, bilateral ovariectomy (Ovx), and bilateral ovariectomy followed by subcutaneous injections of 17ß-estradiol (Ovx + Est). After 4 weeks, urodynamic studies were done to measure the contraction interval and contraction pressure. The expression and cellular localization of AQP2 and AQP3 were determined by Western blot and immunohistochemistry in rat urinary bladder. RESULTS: In cystometrograms, the contraction interval (min) was significantly lower in the Ovx group (2.8 ± 0.32) than in the control group (5.1 ± 0.56) but was increased after estrogen treatment (8.8 ± 0.29). Conversely, the average contraction pressure (mmHg) was higher in the Ovx group (28.2 ± 2.3) than in the control group (22.3 ± 1.06) and decreased after estrogen treatment (23.1 ± 2.02). AQP2 expression was localized in the cytoplasm of the epithelium, whereas AQP3 was found only in the cell membrane of the epithelium. The protein expression of both AQP2 and AQP3 was significantly lower after ovariectomy and was restored to the control levels after 17ß-estradiol treatment. CONCLUSIONS: Hormonal alteration causes a significant change in the expression of AQP2 and AQP3. These findings suggest that AQPs might have a functional role in the detrusor overactivity that occurs in association with hormonal alteration in female rat.

Expression of caveolin-1 in rat urinary bladder with cyclophosphamide-induced cystitis.

PURPOSE: The purposes of this study were to investigate the effect of cyclophosphamide (CYP)-induced inflammatory cystitis on caveolin 1 in rat urinary bladder and to determine the role of these molecules in the bladder dysfunction that occurs in inflammatory change in rat urinary bladder. METHODS: Female Sprague-Dawley rats were divided into control (n=30) and experimental (n=30) groups. Cystitis in experimental group was induced by intraperitoneal injection of CYP (200 mg/kg). The control group underwent an intraperitoneal saline injection. After 3 days, urodynamic studies were done to measure the contraction interval and contraction pressure. The expression and cellular localization of caveolin 1 were determined by Western blot and immunofluorescent study in rat urinary bladder. RESULTS: In cystometrograms, the contraction interval (minute) was significantly increased in the CYP-induced cystitis rats (15.8±1.5) than in the control group (6.3±0.5) (P<0.05). Conversely, the average contraction pressure (mmHg) was significantly higher in the CYP-induced cystitis rats (15.6±1.7) than in the control group (11.3±0.5) (P<0.05). Caveolin 1 was expressed in the capillaries, arteriols and venules. The protein expression of caveolin 1 was significantly decreased in the CYP-induced cystitis rats (P<0.05). CONCLUSIONS: Inflammatory change of urinary bladder maybe causes a significant change in the expression of caveolin 1. These findings suggest that caveolin 1 might have a functional role in the bladder dysfunction related with cystitis in rat urinary bladder.

Expression and localization of aquaporins in benign prostate hyperplasia and prostate cancer.

The aquaporin (AQP) families of water channels are intrinsic membrane proteins that facilitate selective water and small solute movement across the plasma membrane. The purposes of this study were to determine the expression and localization of AQPs in benign prostatic hyperplasia and prostate cancer. Prostatic tissue was collected from patients with benign prostatic hyperplasia or prostate cancer by transurethral resection of the prostate. The expression and cellular localization of the AQPs were determined in the human prostate by Western blot and immunohistochemistry. AQP1, 3, and 9 were expressed in the human prostate. Western blot analysis revealed bands at 28-36 kDa for the AQP1, 3, and 9 proteins. Of these proteins, AQP3 and 9 were expressed in the epithelium. Immunolabeling showed that AQP1 was mainly expressed in the capillaries and venules of the prostate, AQP9 was expressed in the cytoplasm of the epithelium, and AQP3 was mainly associated with the plasma membrane of the prostatic epithelium. Only AQP3 expression was localized in the cell membrane, and expressed AQP3 was translocated to the cytoplasm in prostate cancer. The epithelium in the human prostate expresses AQP3 and 9 proteins, and the capillaries and venules of the prostate express AQP1. Characterizing or modifying the expression of AQP3 may lead to an understanding of the role of the AQPs in human prostatic disease.

Distribution of interstitial cells of Cajal and expression of nitric oxide synthase after experimental bladder outlet obstruction in a rat model of bladder overactivity.

AIMS: Recent studies have showed that interstitial cells (ICs) are widely distributed in the genitourinary tract and have suggested their involvement in spontaneous electrical activity and muscle contraction. Nitric oxide (NO) is thought to play a role in bladder overactivity related with bladder outlet obstruction (BOO). The purposes of this study were to investigate the effect of bladder overactivity induced by BOO on ICs and nitric oxide synthase (NOS) isoforms in rat urinary bladder. METHODS: Female Sprague-Dawley rats (230-240 g, n = 40) were divided into two groups: control (group Con, n = 20) and partial BOO (group BOO, n = 20). After 4 weeks, urodynamic studies measuring contraction interval and contraction pressure were done. The cellular localization of cKit immunoreactive ICs and the expression of endothelial NOS (eNOS) and neuronal NOS (nNOS) were determined by Western blot and immunohistochemistry in the rat urinary bladder. RESULTS: Filling cystometry studies demonstrated a reduced interval between voiding contractions and an increased voiding pressure in BOO bladders. The contraction interval time (2.9 ± 0.35 min) was significantly decreased in the BOO group compared to the control (6.1 ± 0.05; P < 0.05). The population of ICs was increased in the suburothelial and muscle layers in BOO bladders. ICs had a close contact with each other and neighboring nNOS expressing cells. CONCLUSIONS: These results demonstrated an increased population of ICs in the BOO rat model and suggest that the functional change of ICs and NOS isoforms may contribute to the pathophysiology of bladder overactivity induced by BOO.

Effects of estrogens on the expression of caveolin-1 in the urinary bladders of female rats.

PURPOSE: The purposes of this study were to investigate the effect of hormonal alterations on the expression of caveolin-1 in the urinary bladders of ovariectomized rats and to determine the role of caveolin-1 in the overactivity of the detrusor muscle that occurs with hormonal alterations in rats. METHODS: Female Sprague-Dawley rats were divided into three groups: a control group, a group that underwent bilateral ovariectomy (Ovx), and a group that underwent bilateral ovariectomy followed by subcutaneous injections of 17ß-estradiol (Ovx+Est). After 4 weeks, urodynamic studies were done to measure the contraction interval and contraction pressure. The expression and cellular localization of caveolin-1 were determined by Western blot and immunofluorescence in the urinary bladders of rats. RESULTS: On cystometrograms, the contraction interval was significantly shorter in the Ovx group (3.0±0.3 minute) than in the control group (5.6±0.5 minute) but was longer in the Ovx+Est group (9.2±0.4 minute) (P<0.05). Conversely, the average contraction pressure was higher in the Ovx group (26.4±0.48 mmHg) than in the control group (21.8±0.37 mmHg) but was lower in the Ovx+Est group (23.9±0.76 mmHg) (P<0.05). Caveolin-1 was expressed in the capillaries, arterioles, and venules. Expression of the protein caveolin-1 was significantly lower after ovariectomy and was restored to control levels after treatment with 17ß-estradiol (P<0.05). CONCLUSIONS: Hormonal alterations cause a significant change in the expression of caveolin-1, which suggests that caveolin-1 might have a functional role in the overactivity of the detrusor muscle related to hormonal alterations in the urinary bladders of rats.

Characterization of porcine multipotent stem/stromal cells derived from skin, adipose, and ovarian tissues and their differentiation in vitro into putative oocyte-like cells.

The present study evaluated the alkaline phosphatase activity, cell cycle stage, expression of markers and early transcriptional factors, and in vitro differentiation into selected cell lineages of porcine stem/stromal cells (SCs) isolated from skin (SSCs), adipose, and ovarian (OSCs) tissues. Skin and adipose SCs were isolated from a 6-month-old miniature pig, whereas OSCs were isolated from a newly born piglet. Isolated cells exhibited fibroblast-like cell population with significant renewal capacity and formed colonies by cells out-growth. All cells were positive for alkaline phosphatase activity and showed a relatively lower population at G0/G1 phase of the cell cycle. SCs derived from all tissues were strongly positive for cell surface markers, such as CD29, CD44, CD90, and vimentin. Further, relatively lower expression of cytokeratin and immunophenotype markers, such as major histocompatibility complex II (MHCII) and swine leukocyte antigen (SLA), was also observed. SCs derived from all tissues positively expressed the transcription factors, such as Oct-3/4, Nanog, and Sox-2. After induction, all SCs successfully differentiated into osteocytes and adipocytes and expressed the lineage specific marker genes. Further, cells from all tissues exhibited their potential for in vitro oogenesis with morphological changes and expression of markers during the germ-cell formation, namely Oct-4, growth differentiation factor 9b, c-Mos, Vasa, deleted in azoospermia-like gene, zona pellucida C, and follicle stimulating hormone receptor. Apart from basic features and selected lineage potential among all types of cells, OSCs possessed a greater ability to differentiate into the germ cell lineage in vitro.

Distribution of interstitial cells of cajal in menopausal rat urinary bladder showing detrusor overactivity.

PURPOSE: Recent studies have showed that interstitial cells of Cajal (ICCs) are widely distributed in the genitourinary tract and have suggested their involvement in spontaneous electrical activity and muscle contraction. The purposes of this study were to investigate the effect of estrogen on ICCs in rat urinary bladder from the detrusor overactivity induced by ovariectomy. MATERIALS AND METHODS: Female Sprague-Dawley rats (230-240 g, N=60) were divided into three groups: control (N=20), bilateral ovariectomy (Ovx, N=20), and bilateral ovariectomy followed by subcutaneous injections of 17 ß-estradiol (50 mg/kg/day, Ovx + Est, N=20). After 4 weeks, urodynamic studies measuring contraction interval and contraction pressure were done. The cellular localization of ICCs was determined by immunohistochemistry in the rat urinary bladder. RESULTS: Filling cystometry studies demonstrated a reduced interval between voiding contractions and an increased voiding pressure in Ovx group. The approximate the contraction interval (min) was (3.9±0.25) significantly decreased in the Ovx group compared to the control group (6.7±0.15), which was increased after estrogen treatment (9.7±0.22) (p<0.05). Conversely, the average contraction pressures (mmHg) were increased in the Ovx group (28.9±2.1) compared to the control group (21.2±1.45), and decreased after estrogen treatment (24.8±2.21) (p<0.05). The population of c-Kit immunoreactive ICCs was decreased in both the urothelial and muscle layers in Ovx bladders, which increased to the control value after estrogen treatment. CONCLUSIONS: These results demonstrated an decreased immunoreactivity of ICCs in the menopausal rat model and suggest that thedecreased population of ICCs expression may contribute to the modulation of bladder overactivity induced by menopause.

The Expression of AQP1 and eNOS in Menopausal Rat Urinary Bladder.

PURPOSE: Aquaporins (AQPs) have been reported to be expressed in rat and human urothelium. Nitric oxide (NO) is thought to play an important role in the bladder overactivity related to menopause. The purpose of this study was to investigate the effect of hormonal alteration on the expression of AQP1 and eNOS in menopausal rat urinary bladder. MATERIALS AND METHODS: Female Sprague-Dawley rats (230-240 g, N=30) were divided into three groups: control (N=10), bilateral ovariectomy (Ovx, N=10), and bilateral ovariectomy followed by subcutaneous injections of 17ß-estradiol (50 mg/kg/day, Ovx+Est, N=10). After 4 weeks, urodynamic studies measuring the contraction interval and contraction pressure were done. The expression and cellular localization of AQP1 and eNOS were determined by performing Western blotting and immunohistochemistry on the rat urinary bladder. RESULTS: The approximate contraction interval (min) was significantly decreased in the Ovx group (3.9±0.25) compared to the control group (6.7±0.15), and was increased after estrogen treatment (9.7±0.22) (p<0.05). The AQP1 and eNOS immunoreactivities were localized in the same areas: capillaries, arterioles, and venules of the lamina propria. The protein expression of AQP1 was not changed significantly, whereas eNOS expression was significantly decreased in the Ovx group and restored to the control value in the Ovx+Est group. CONCLUSIONS: This study showed that ovariectomy causes a significant change in e-NOS expression without a change in AQP1 in menopausal rat urinary bladder. This may imply that e-NOS has a functional role in the bladder overactivity that occurs in association with menopause.

Changes in aquaporin 1 expression in rat urinary bladder after partial bladder outlet obstruction: preliminary report.

PURPOSE: Aquaporins (AQPs) are membrane proteins that facilitate water movement across biological membranes. AQPs are also called water channels, and they have recently been reported to be expressed in rat and human urothelium. The purposes of this study were to investigate the effect of bladder outlet obstruction (BOO) on the rat urothelium and AQP1 expression in rat urothelium. MATERIALS AND METHODS: Female Sprague-Dawley rats (230-240 g each, n=20) were divided into 2 groups: the sham group (the Con group, n=10) and the partial BOO group (the BOO group, n=10). The BOO group underwent a partial BOO. The expression and cellular localization of AQP1 were determined by performing Western blotting and immunohistochemistry on the rat urinary bladder. RESULTS: AQP1 immunoreactivity in both the control and the BOO groups was localized in the capillaries, arterioles, and venules of the lamina propria of the urinary bladder. The protein expression of AQP1 was significantly increased in the BOO group. CONCLUSIONS: This study showed that BOO causes a significant increase in the expression of AQP1. This may imply that AQP1 has a functional role in the detrusor instability that occurs in association with BOO.

Cadmium down-regulates human OGG1 through suppression of Sp1 activity.

Cadmium is a well known human and animal carcinogen and is a ubiquitous contaminant in the environment. Although the carcinogenic mechanism of cadmium is a multifactorial process, oxidative DNA damage is believed to be of prime importance. In particular, cadmium suppresses the capacity of cells to repair oxidative DNA damage. In this study, cadmium treatment led to a significant increase in gamma-ray-induced 8-oxoguanine (8-oxoG) formation. Western blotting and semiquantitative reverse transcription-PCR revealed that cadmium treatment caused a decrease in the expression level of human OGG1 (8-oxoguanine-DNA glycosylase-1; hOGG1) in human fibroblast GM00637 and HeLa S3 cells. In addition, the cadmium-mediated decrease in hOGG1 transcription was the result of decreased binding of the transcription factor Sp1 to the hOGG1 promoter. Finally, we show that an increase in the functional hOGG1 expression level could inhibit the cadmium-mediated increase in gamma-ray-induced 8-oxoG accumulation as well as in gamma-radiation-induced mutation frequency at the HPRT (hypoxanthine-guanine phosphoribosyltransferase) gene locus. These results suggest that cadmium attenuates removal of gamma-ray-induced 8-oxoG adducts, which in turn increases the mutation frequency, and that this effect might, at least in part, result from suppression of hOGG1 transcription via inactivation of Sp1 as a result of cadmium treatment.