Protamine Sulfate Induced Bladder Injury Protects from Distention Induced Bladder Pain

Abstract

Purpose Bladder pain is a debilitating symptom of many urologic conditions, and there is no generally effective treatment. Abnormal urothelial turnover is common to multiple disease states, but the specific components of urothelial injury and the resulting molecular signals that lead to bladder pain are unknown. We examined mouse models of bladder injury induced by uropathogenic E. coli (UPEC), protamine sulfate (PS), and bacterial lipopolysaccharide (LPS) to identify cellular and molecular correlates underlying pain sensitization in response to the stimuli. Materials and Methods C57BL/6 female mice were given intravesicular PS, LPS or UPEC, and the impact of each on nociception was determined by measuring the evoked visceromotor response to bladder distention at 24 hours post inoculation. Levels of pyuria and tissue inflammation were examined by urinary cytology and tissue histology. Quantitative PCR and gene expression analysis were used to identify injury profiles associated with nociception. Results PS treatment was significantly analgesic upon bladder distention. PS-treated bladders did not exhibit pyuria or extensive tissue damage. PS injury was associated with a global decrease in expression of inflammation-associated genes. In contrast, UPEC injury significantly increased the nociceptive response to bladder distention. LPS treatment did not affect nociception. Finally, injury-induced expression of inflammation-associated genes correlated with nociceptive responses. Conclusion PS treatment of the bladder is analgesic, tissue protective, and suppresses inflammatory cytokine expression normally associated with nociception. Additionally, the injury modalities that result in differential tissue response patterns provide an innovative method for identification of mediators of visceral pain.

Estrogenic Modulation of Uropathogenic Escherichia coli Infection Pathogenesis in a Murine Menopause Model

“…Fivemicrometer-thick tissue sections were stained with hematoxylin and eosin. Inflammation scores of infected bladders were determined as described previously (30).…”

“…Bacterial titers were calculated as CFU/ml of urine. Urine sediments were obtained by cyto-centrifuging 50 l of a 1:5 dilution of the urine onto poly-L-lysine-coated glass slides, which were then stained for inflammatory scoring as described previously (30).…”

Imidazolium Salts as Small-Molecule Urinary Bladder Exfoliants in a Murine Model

“…These conditions confer burdensome symptoms to many patients, and as the causes are poorly understood, directed and evidence-based management options are lacking. However, there is evidence that exfoliation of the superficial bladder epithelium might mitigate pain associated with these conditions (29). In part, this may be because the uroepithelial cells represent a primary source of proinflammatory cytokines and chemokines in bladder inflammatory responses.…”

“…For tissue culture experiments, compounds were diluted from the working 1 mM stock in RPMI 1640 medium (Gibco) containing 10% fetal bovine serum (FBS) (Sigma). Protamine sulfate (PS) (Sigma) (50 mg/ml in water) was used as an established comparator method for bladder epithelial exfoliation (29), and 0.8% DMSO in water was used as a vehicle-only control.…”

“…A second dose was similarly administered 12.5 h after the initial inoculation. Mice were euthanized after 16 h of compound exposure (3.5 h after the second inoculation), a schedule based on recent studies with PS (29).…”