(154) Microarray and Pathway Analysis of Corpora Cavernosal Tissue from Peyronie’s and Prostatectomy Patients with Erectile Dysfunction in Comparison to a Rat Cavernous Nerve Resection Model

Abstract

Abstract Introduction Prostatectomy patients are at high risk of developing erectile dysfunction (ED) that is refractory to PDE5 inhibitors. The cavernous nerve (CN), which innervates the penis, is frequently damaged during prostatectomy, causing loss of neurotransmission, remodeling of penile architecture, including abundant smooth muscle apoptosis and fibrosis, resulting in ED. Objective In this study we perform microarray and pathway analysis to identify signaling mechanisms that are altered with ED and penile remodeling, in order to develop novel therapies for ED prevention and treatment. Methods Corpora cavernosal tissue was obtained from Peyronie’s (control, n=3) and prostatectomy (control, n=3) patients that underwent prosthesis implant to treat ED. Sprague Dawley rat penis was obtained from rats that underwent bilateral CN resection (n=5) or sham surgery (controls, n=5), and corpora cavernosa was dissected after two days. RNA was extracted using TRIzol, DNase treated, and purified by Qiagen mini kit. Microarray was performed using the Human Gene 2.0 ST Array and the RU34 rat array. Differentially expressed genes were identified in corpora cavernosa from prostatectomy patients using several analytical tools (ShinyGO, WebGestalt) and databases (GO, Reactome). Comparison of patient and rat pathway analysis was performed. Two technical replicates were examined. A two-fold change was used as threshold for differential expression. FDR<0.05 was considered significant for enrichment terms. Results Microarray identified 197 differentially expressed protein-coding genes in corpora cavernosa from prostatectomy patients, with 100 genes up, and 97 genes down regulated. 112 of the 197 DEGs were non-protein-coding genes of which 26 had documented associations (9 up-regulated and 17 down-regulated; 13 associated with cell proliferation). Thus, the overall changed expression of these documented non-protein-coding genes would be expected to favor a reduction in cell growth compared with Peyronie’s control. For the rat ED model, microarray detected 182 differentially expressed protein-coding genes. Over Representation Enrichment Analysis showed enrichments for cell death, stress and cellular development. Examination of the role of individual genes found altered signaling for both proliferation and cell death, indicating while apoptosis is abundant at this time frame in the rat ED model, proliferation also occurs initially, prior to apoptotic dominance. Conclusions Prostatectomy patients display alterations in gene expression in their corpora cavernosa that are consistent with decreased growth, likely impacting tissue repair and regenerative processes. Non-protein-coding RNAs may play a crucial role in ED development in prostatectomy patients. In our CN resection rat ED model, which represents altered signaling early in the architectural remodel process that occurs after CN injury, both cell death and proliferation are the acute response followed by apoptosis domination. Microarray and pathway analysis identify strategic points for clinical intervention for ED therapy development. Disclosure No