The Expression of AQP1 and eNOS in Menopausal Rat Urinary Bladder

Mechanistic effect of human umbilical cord blood derived mesenchymal stem cells on the submandibular salivary gland in ovariectomized rats

We performed this study to understand the effect of human umbilical cord blood derived mesenchymal stem cells (hUCB-MSCs) on the submandibular gland after bilateral ovariectomy. For this, 21 adult female rats were distributed equally among 3 groups: the sham-operated group (SHAM); the ovariectomized group (OVX); and the OVX group that received repeated intravenous injections of the hUCB-MSCs (OVX + hUCB-MSCs). We used reverse transcription – PCR to analyze for the gene expression of AQPs 3, 4, 5, and BMP-6. The cellular localization and expression of human CD105, human CD34, proliferating nuclear antigen (PCNA), single-stranded DNA (ss-DNA), caspase 3, AQP1, and α smooth muscle actin (α-SMA) were determined immunohistochemically. In the OVX group, a significant decrease in the gene expression of AQP3, AQP4, and BMP6, as well as the acinar area % was detected, while area % of granular convoluted tubules (GCTs) showed a significant increase. A significant decrease in area % staining positively for AQP1 and α-SMA was noted. An obvious improvement in the structure of the submandibular gland was demonstrated in the group injected with hUCB-MSCs, as well as a significant increase in the gene expression of AQP3, AQP4, and BMP6. The acinar and GCT area %, as well as the different measured markers, were relatively normal. This demonstrates that E2-deficiency induces structural changes to the submandibular gland. Moreover, a definite amelioration of the structure and function of the submandibular gland was detected after the administration of hUCB-MSCs.

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.

Signalling molecules in the urothelium

The urothelium was long considered to be a silent barrier protecting the body from the toxic effects of urine. However, today a number of dynamic abilities of the urothelium are well recognized, including its ability to act as a sensor of the intravesical environment. During recent years several pathways of these urothelial abilities have been proposed and a major part of these pathways includes release of signalling molecules. It is now evident that the urothelium represents only one part of the sensory web. Urinary bladder signalling is finely tuned machinery of signalling molecules, acting in autocrine and paracrine manner, and their receptors are specifically distributed among different types of cells in the urinary bladder. In the present review the current knowledge of the formation, release, and signalling effects of urothelial acetylcholine, ATP, adenosine, and nitric oxide in health and disease is discussed.

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.

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.

Nitric oxide in neurodegeneration: potential benefits of non-steroidal anti-inflammatories

The cellular messenger nitric oxide (NO) has been linked to neurodegenerative disorders due to the increased expression of the enzymes that catalyze its synthesis in postmortem tissues derived from sufferers of these diseases. Nitrated proteins have also been detected in these samples, revealing that NO is biologically active in regions damaged during neurodegeneration. Modulation of NO levels has been reported not only in the neurons of the central nervous system, but also in the glial cells (microglia and astroglia) activated during the neuroinflammatory response. Neuroinflammation has been found in some neurodegenerative conditions, and inhibition of these neuroinflammatory signals has been shown to delay the progress of such disorders. Thus NO and the pathways triggering its release are emerging as an important research focus in the search for strategies to prevent, halt or cure neurodegenerative diseases.