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Detrusor overactivity (DO) is the abnormal response of the urinary bladder to physiological stretch during the filling phase of the micturition cycle. The mechanisms of bladder smooth muscle compliance upon the wall stretch are poorly understood. We previously reported that the function of normal detrusor is regulated by TREK-1, a member of the mechanogated subfamily of two-pore-domain potassium (K2P) channels. In the present study, we aimed to identify the changes in expression and function of TREK-1 channels under pathological conditions associated with DO, evaluate the potential relationship between TREK-1 channels and cytoskeletal proteins in the human bladder, and test the possibility of modulation of TREK-1 channel expression by small RNAs. Expression of TREK-1 channels in DO specimens was 2.7-fold decreased compared with control bladders and was associated with a significant reduction of the recorded TREK-1 currents. Isolated DO muscle strips failed to relax when exposed to a TREK-1 channel opener. Immunocytochemical labeling revealed close association of TREK-1 channels with cell cytoskeletal proteins and caveolins, with caveolae microdomains being severely disrupted in DO specimens. Small activating RNA (saRNA) tested in vitro provided evidence that expression of TREK-1 protein could be partially upregulated. Our data confirmed a significant downregulation of TREK-1 expression in human DO specimens and provided evidence of close association between the channel, cell cytoskeleton, and caveolins. Upregulation of TREK-1 expression by saRNA could be a future step for the development of in vivo pharmacological and genetic approaches to treat DO in humans. [ABSTRACT FROM AUTHOR]

In the present study, we aimed to determine whether mice with coronavirus-induced encephalomyelitis (CIE) develop neurogenic bladder dysfunction that is comparable with the neurogenic detrusor overactivity observed in patients with multiple sclerosis. Adult mice (C57BL/6J, 8 wk of age, n = 146) were inoculated with a neurotropic strain of mouse hepatitis virus (A59 strain) and followed for 4 wk. Inoculation with the virus caused a significant neural deficit in mice with an average clinical symptom score of 2.6 ± 0.5 at 2 wk. These changes were accompanied by 25 ± 5% weight loss at 1 and 2 wk postinoculation (P ≤ 0.001 vs. baseline) followed by a recovery phase. Histological analysis of spinal cord sections revealed multifocal sites of demyelinated lesions. Assessment of micturition patterns by filter paper assay determined an increase in the number of small and large urine spots in CIE mice starting from the second week after inoculation. Cystometric recordings in unrestrained awake animals confirmed neurogenic bladder overactivity at 4 wk postinoculation. One week after inoculation with the A59 strain of mouse hepatitis virus, mice became increasingly sensitive to von Frey filament testing with responses enhanced by 45% (n = 8, P ≤ 0.05 vs. baseline at 4 g); however, this initial increase in sensitivity was followed by gradual and significant diminution of abdominal sensitivity to mechanical stimulation by 4 wk postinoculation. Our results provide direct evidence showing that coronavirus-induced demyelination of the central nervous system causes the development of a neurogenic bladder that is comparable with neurogenic detrusor overactivity observed in patients with multiple sclerosis. [ABSTRACT FROM AUTHOR]