Evaluation of the Therapeutic Effect of PRP in the Urethral Stricture

Aims and Objectives Urethral stricture (US) is the result of lumen stricture affecting the urethra due to fibrosis; however, the effective treatment to prevent fibrosis formation is not known. In this study, the effects of platelet-rich plasma (PRP) on a urethral injury model of male rats were evaluated for the expression of collagen type I, collagen type III, and tumor necrosis factor-α (TNF-α) using immunohistochemical techniques and the expression of miR-9-5p, miR-185, miR-29, and miR-146a using reverse transcription-polymerase chain reaction (RT-PCR) technique. Materials and Methods Thirty-six rats were randomly divided into six equal groups: a normal control group, a US group, a PRP group, a urethrotomy (UT) group, a US + UT group, and a US + UT + PRP group. All rats were sacrificed after the final procedure, 15 days later. Urethral tissue samples were examined using immunohistochemical techniques with TNF-α, collagen I, and collagen III antibodies, and were examined for miR-9-5p, miR-185, miR-29, and miR-146a expression using the RT-PCR technique. Results Group 2 was milder, and Group 4 had more lymphocyte infiltration of hemorrhagic areas in the lamina propria. TNF-α, collagen I, and collagen III immunoreactivities were high in all PRP-applied groups. While miR-9-5p, miR-185, miR-146, and miR-9 expressions decreased in the experimental groups except for Group 6. Conclusion PRP injection during UT modulates inflammation by increasing TNF-α expression, regulates connective tissue healing by increasing collagen III synthesis more than collagen I, and also suppresses miR-9-5p, miR-185, miR-146, and miR-9 to prevent fibrosis.