Presentation Authors: Uros Milenkovic*, Rekin's Janky, Leuven, Belgium, Georgios Hatzichristodoulou, Wurzburg, Germany, Koen van Renterghem, Hasselt, Belgium, Selim Cellek, Chelmsford, United Kingdom, Trinity Bivalacqua, Baltimore, MD, Dirk De Ridder, Maarten Albersen, Leuven, Belgium
Introduction: Peyronie&[prime]s disease (PD) is an acquired fibrotic process affecting the tunica albuginea (TA) of the penis. The development of fibrotic plaques can lead to penile curvature/deformities, shortening and erectile dysfunction. Medical treatments are lacking due to limited understanding of disease pathophysiology. Elucidation of molecular pathways and cell types involved could lead to the development of novel disease models and conservative therapeutics.Our purpose was to characterise the transcriptomic signature of plaques from PD patients and compare it to normal TA using RNA sequencing (RNAseq) and network analysis.
Methods: We collected surgical TA samples from 6 PD patients and 6 control patients where RNAseq was performed, followed by gene ontology, gene set enrichment (GSEA) and transcriptional regulation (iRegulon) analysis. Identical samples that were used for RNAseq were used for qPCR validation, as well as additional samples, not included in the RNAseq analysis, that were used as biological replicates/external validation (N=5). Moreover, biological validation of our hypothesis was provided through immunohistochemical staining of patient samples (10 controls and 20 PD samples).
Results: This is the first report using human samples for transcriptome-wide analysis of genital tract fibrosis. Differential gene expression identified 819 over- and 475 underexpressed genes in PD patients. Gene ontology reveals an active inflammation with extracellular matrix remodelling and leukocyte mediated immunity. Using GSEA and iRegulon we uncovered that nearly 50% of enriched genes were NF-kB (TNFÎ± and Toll-like receptors (TLR)-activated) and JAK/STAT (through interleukins/interferons)-regulated. Validation of genes involved in these pathways was performed using qPCR (IL6, CCL2, CXCL2, SPP1, CCL3, CD14, TLR7, IL15, CXCL11, VCAM1, SOCS3, LAMP3). Relative gene expression using RNAseq and qPCR correlated strongly within our samples. These findings suggest an important macrophage-related signature. Immunohistochemical staining for macrophages (CD68) corroborated this hypothesis.
Conclusions: Our analysis suggests that, even in an established, stable PD-plaque, inflammatory pathways are still active. We show for the first time that TLR-activation could be an important pathway in PD-pathophysiology. Additionally, we suggest that this process is potentially maintained through macrophages. Both could lead to development of novel druggable targets and more representative disease models.
Source of Funding: This research has been funded by the Fund for Peyronie&[prime]s Disease Research, European Society for Sexual Medicine (ESSM) and the Fund for Translational Biomedical Research (FTBR) (&[Prime]Klinische onderzoeks- en opleidingsraad&[Prime] (KOOR)) of KU/