Role of Myeloperoxidase in ROS Generation and Inflammation Response on Prostate Epithelial Cells

Myeloperoxidase (MPO) has been reported in prostate tissue, and considering its pro-oxidant properties, this location might be linked to prostate pathology. The possibility that the glandular prostatic tissue might be the source of MPO and its potential inflammatory effects must be tested. Human prostate material was obtained from prostate biopsies and radical prostatectomies. Immunohistochemistry was performed using MPO-specific human antibody. In situ hybridization using MPO-specific probes and laser-assisted microdissection for quantitative real-time RT-PCR were performed to observe whether MPO is being produced in prostate tissue. Mass spectrometry on prostate biopsies was used to detect products of MPO activity in nucleic acids (DNA/RNA). MPO contribution to intracellular accumulation of ROS and interleukin-8 in prostatic epithelial cells was monitored in vitro. Immunohistochemistry confirmed cellular localization of MPO in epithelial cells of the prostate. The staining varied from light to high intensity. In situ hybridization did not address the presence of mRNA coding for MPO. No MPO-specific modifications on nucleic acids were detected. Mox-LDL was a major factor inducing ROS and cytokines production in prostatic epithelial cells. We did not demonstrate that MPO was synthetized by prostatic epithelial cells. However, in vitro experiments showed the ability of MPO to potentiate the ROS production and inflammation on prostate epithelial cells. Results do not allow us to demonstrate a role of MPO in prostate to date but further studies are mandatory to focus on the potential impact of MPO in the development of prostatic diseases.