Prostate-specific deletion of Cdh1 induces murine prostatic inflammation and bladder overactivity

Benign Prostatic Hyperplasia (BPH) is an age-related debilitating prostatic disease that is frequently associated with prostatic inflammation and bothersome lower urinary tract symptoms (LUTS). Animal models have shown that formalin- and bacterial-induced prostatic inflammation can induce bladder dysfunction; however, the underlying mechanisms contributing to prostatic inflammation in BPH and bladder dysfunction are not clear. We previously reported that E-cadherin expression in BPH is down-regulated in hyperplastic nodules compared to expression in adjacent normal tissues. Here, we explored the potential consequences of prostatic E-cadherin down-regulation on the prostate and bladder in vivo using an inducible murine model of prostate luminal epithelial-specific deletion of Cdh1. The PSA-CreERT2 transgenic mouse strain expressing tamoxifen-inducible CreERT2 recombinase driven by a 6-kb human PSA promoter/enhancer was crossed with the B6.129-Cdh1tm2Kem/J mouse to generate bigenic PSA-CreERT2/Cdh1-/- mice. Deletion of E-cadherin was induced by transient administration of tamoxifen when mice reached sexual maturity (7 weeks of age). At 21-23 weeks of age, the prostate, bladder, and prostatic urethra were examined histologically, and bladder function was assessed using Void Spot Assays and cystometry. Mice with Cdh1 deletion had increased prostatic epithelial hyperplasia, inflammation, and stromal changes at 21-23 weeks of age, as well as changes in bladder voiding function compared to age-matched controls. Thus, loss of E-cadherin in the murine prostate could result in prostatic defects that are characteristic of BPH and lower urinary tract symptoms, suggesting that E-cadherin down-regulation could be a driving force in human BPH development and progression.