Login to Access Video or Poster Abstract: MP82-07
Sources of Funding: SUFU OAB Grant

Introduction

Menopause increases risk of persistent UTI which manifests with chronic lower urinary tract symptoms (LUTS). While treatment focuses on eradicating pathogens (e.g. antibiotics), we lack an understanding of host responses which can lead to bladder functional changes, including refractory LUTS. In this study, we sought to measure host responses, including voiding behavior, urothelial gene expression, and bladder morphology. We identified urothelial genes influenced by OVX that regulated voiding behavior after repetitive LPS intravesical exposure.

Methods

Female C57BL6 mice underwent sham (n=10) or OVX (n=10) surgery. Micturition behavior was measured using voiding spot assay (VSA) performed pre-surgery, 4 weeks post-surgery (but prior to LPS exposure) and after each of three consecutive days of intravesical inoculation of LPS. At end of experiment, animals were euthanized and bladders harvested for Gomori trichome staining. A separate experiment, following same LPS exposure protocol, was performed in 18 mice (sham=9, OVX =9) for microarray analysis of urothelial gene expression (pure urothelial sheet dissections) before LPS, 1d and 3d after LPS exposure, using Affymetrix gene chip for entire mouse transcriptome.

Results

In Fig 1, OVX and sham animals exhibited overactive voiding behavior on day 1 (Fig 1). However, voiding behaviors diverged on days 2 and 3 of LPS treatment with the OVX mice persisting with an overactive voiding phenotype. Gomori trichome staining showed that OVX mice had flattened rugae which was not seen in sham mice. Analysis of microarray data focused on pattern of gene expression changes (cutoff >+10x or <-10x) that mimicked voiding pattern changes for both sham and OVX animals. Six genes (protein) were identified using this focused approach: Nr4a3 (nuclear receptor 4a3), Nr4a1 (nerve growth factor IB), Areg (amphoregulin), Egr1 (early growth response 1), Krt23 (keratin type 1 cytoskeletal 23), and Gm30571 (unknown protein) (Fig 2A, 2B).

Conclusions

Focused microarray analysis revealed 6 urothelial gene expression changes that paralleled voiding changes. These genes involve inflammation, epithelial growth/repair and cytokines. Treating LUTS secondary to inflammation/UTI might target these host response urothelial genes.

Funding

SUFU OAB Grant