Down-regulation of nerve growth factor expression in the bladder by antisense oligonucleotides as new treatment for overactive bladder.
PURPOSE
Nerve growth factor over expression in the bladder has a role in overactive bladder symptoms via the mediation of functional changes in bladder afferent pathways. We studied whether blocking nerve growth factor over expression in bladder urothelium by a sequence specific gene silencing mechanism would suppress bladder overactivity and chemokine expression induced by acetic acid.


MATERIALS AND METHODS
Female Sprague-Dawley® rats anesthetized with isoflurane were instilled with 0.5 ml saline, scrambled or TYE™ 563 labeled antisense oligonucleotide targeting nerve growth factor (12 μM) alone or complexed with cationic liposomes for 30 minutes. The efficacy of nerve growth factor antisense treatments for acetic acid induced bladder overactivity was assessed by cystometry. Bladder nerve growth factor expression levels and cellular distribution were quantified by immunofluorescence staining and enzyme-linked immunosorbent assay. Effects on bladder chemokine expression were measured by Luminex® xMAP® analysis.


RESULTS
Liposomes were needed for bladder uptake of oligonucleotide, as seen by the absence of bright red TYE 563 fluorescence in rats instilled with oligonucleotide alone. At 24 hours after liposome-oligonucleotide treatment baseline bladder activity during saline infusion was indistinct in the sham and antisense treated groups with a mean ± SEM intercontraction interval of 348 ± 55 and 390 ± 120 seconds, respectively. Acetic acid induced bladder overactivity was shown by a decrease in the intercontraction interval to a mean of 33.2% ± 4.0% of baseline in sham treated rats. However, the reduction was blunted to a mean of 75.8% ± 3.4% of baseline in rats treated with liposomal antisense oligonucleotide (p <0.05). Acetic acid induced increased nerve growth factor in the urothelium of sham treated rats, which was decreased by antisense treatment, as shown by enzyme-linked immunosorbent assay and reduced nerve growth factor immunoreactivity in the urothelium. Increased nerve growth factor in bladder tissue was associated with sICAM-1, sE-selectin, CXCL-10 and 1, leptin, MCP-1 and vascular endothelial growth factor over expression, which was significantly decreased by nerve growth factor antisense treatment (p <0.01).


CONCLUSIONS
Acetic acid induced bladder overactivity is associated with nerve growth factor over expression in the urothelium and with chemokine up-regulation. Treatment with liposomal antisense suppresses bladder overactivity, and nerve growth factor and chemokine expression. Local suppression of nerve growth factor in the bladder could be an attractive approach for overactive bladder. It would avoid the systemic side effects that may be associated with nonspecific blockade of nerve growth factor expression.
['Kashyap|Mahendra|M|', 'Kawamorita|Naoki|N|', 'Tyagi|Vikas|V|', 'Sugino|Yoshio|Y|', 'Chancellor|Michael|M|', 'Yoshimura|Naoki|N|', 'Tyagi|Pradeep|P|']
D000704:Analysis of Variance D000818:Animals D015536:Down-Regulation D004797:Enzyme-Linked Immunosorbent Assay D007150:Immunohistochemistry D018613:Microscopy, Confocal D020932:Nerve Growth Factor D016376:Oligonucleotides, Antisense D051381:Rats D017207:Rats, Sprague-Dawley D015398:Signal Transduction D001743:Urinary Bladder D053201:Urinary Bladder, Overactive
nerve growth factor oligonucleotide overactive bladder urothelium bladder overactivity chemokines acetic acid liposomes intercontraction interval sICAM-1 sE-selectin MCP-1 vascular endothelial growth factor AA BO CMG ICI NGF OAB OND PBS VEGF cystometrogram monocyte chemoattractant protein-1 phosphate buffered saline soluble endothelial adhesion molecule soluble intracellular adhesion molecule urinary bladder, overactive