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-CreER^T2 transgenic mouse strain expressing tamoxifen-inducible CreER^T2 recombinase driven by a 6-kb human PSA promoter/enhancer was crossed with the B6.129-Cdh1^tm2Kem/J mouse to generate bigenic PSA-CreER^T2/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.

This data collection details the following supplemental figures associated with the manuscript, describing a murine Cdh1 knockout model of benign prostatic hyperplasia and lower urinary tract symptoms (BPH/LUTS).

Supplemental Figure Legends

Supplemental Figure S1. A. Breeding scheme for the generation of PSA-CreER^T2+/-:Cdh1^fl/fl (Cdh1-cko) and Cdh1^fl/fl Control mice. B. Genotypic analysis of tail DNA from PSA-CreER^T2+/- and Cdh1^fl/fl offspring.  Cdh1^fl/fl WT amplified 243 bp and Mut amplified 310 bp. -C, negative control without template DNA. L, ladder size. WT, wild-type, Mut, mutant. C. Treatment timeline for animal cohorts in the study. Cohort 1: Tamoxifen (TAM, 3 mg/40 g i.p.) was injected daily for 5 consecutive days in adult male mice at 7 weeks of age and animals were followed to 21-23 weeks of age (single TAM, or 1 X TAM). Cohort 2:  Tamoxifen (TAM, 3 mg/40 g i.p.) was injected daily for 5 consecutive days in adult male mice at 7 weeks of age and at 19 weeks of age (double TAM, or 2 X TAM).  Both cohorts of animals were utilized in the void spot assay and cystometry experiments. The background strain in all cases was C57BL/6J. TAM, tamoxifen, Euth, euthanasia.

Supplemental Figure S2. A. Histology of murine prostate lateral, dorsal and anterior prostate lobes. H&E staining of transverse sections of prostate lateral (top panels), dorsal (center panels) and anterior (bottom panels) lobes from Control and Cdh1^-/- mice at 21 to 23 weeks of age. Original magnification, 10×, inset 40×. B. H&E staining of transverse sections of prostate lateral (top panels), dorsal (center panels) and anterior (bottom panels) lobes from tamoxifen-induced Cdh1^+/- mice at 21 to 23 weeks of age. Original magnification, 5×, inset 40×. Scale bars indicate 400 µm in 5×, 200 µm in 10×, 50 µm in 40×.

Supplemental Figure S3. Prostate proliferation changes induced by E-cadherin deletion.  A. Prostate mass of Control and Cdh1^-/- mice at 21-23 weeks of age, vlp, ventral-lateral prostate, dp, dorsal prostate, ap, anterior prostate. Data represent mean ± S.D, number of mice in each group in parentheses. *, p < 0.05.

Supplemental Figure S4. Effects of Cdh1-deficiency on bladder voiding in cohort 1 mice treated with a single tamoxifen pulse and analyzed at 21-23 weeks of age (Single TAM pulse). A. Quantification of average void spot on paper assay results from Control and Cdh1^-/- over 4 hours. B. Average single voiding volume and C. Total urine volume over the 4-hour testing period. Numbers of mice in each group are indicated in parentheses. ns, nonsignificant.

Supplemental Figure S5.  Phenotype of Cdh1^-/- mice treated with second pulse of tamoxifen (Double TAM Pulse).  A. Expression of E-cadherin in the ventral lobes of the murine prostate (top panels) and bladder urothelium (bottom panels) in Control or Cdh1^-/- knockout mice at 21 to 23 weeks of age. Original magnification, 40×, inset 40×. B. Histology of murine prostate. H&E staining of transverse sections of prostate ventral lobes. C. Masson’s trichrome staining in transverse sections of prostate ventrallobes. Original magnification, 10×, inset 40×, scale bars indicate 200 µm in 20×, 50 µm 40×.

Supplemental Figure S6. Effects of Cdh1-deficiency on voiding function in mice treated with a single tamoxifen pulse and analyzed at 21-23 weeks of age (Single TAM Pulse). A. Representative traces of in vivo cystometrograms (CMG) in a control (top trace) and in a single tamoxifen pulse treated (lower trace) awake restrained mouse. B. Quantification of intercontraction interval (ICI) and non-voiding contraction (NVC) in Control (n=6) and in TAM treated Cdh1^-/- mice (n=7). ns, nonsignificant.