Clinical Sample Collection

This study was approved by Institutional Review Board (IRB) Protocol and conducted under the guidance of the University of Wisconsin-Madison Human Research Protection Program (HRPP). All human subjects provided informed consent before participating in this study. Midstream urine samples were collected from 26 patients with LUTS and 20 controls without LUTS in the Urology clinic of the University of Wisconsin Hospital according to the approved IRB. Because of the physiological and anatomic differences of lower urinary tract between female and male, the etiology and risk factors of developing LUTS are often separately studied for female and male patients^51,53. In this study, the recruited LUTS patients were men with significant urinary frequency and urgency for a duration of more than 6 months as described by the American Urological Association Symptom Index (AUASI) frequency + urgency symptom scores of >7⁸. Control male patients had no history of significant LUTS and the symptom score ≤3 (detailed patient inclusion and exclusion criteria are provided in Supplementary Fig. S5). Because many LUTS patients have a history of other urologic conditions, including renal cell carcinoma, renal cystic disease, kidney stones, erectile dysfunction, hydrocele, and low-grade prostate cancer, controls were also selected from patients with such diagnostic history not specifically associated with LUTS in order to provide a spectrum of patients that can dilute the effect of confounding variables. The age and body mass index were matched between recruited LUTS and control patients (Supplementary Table S2). After collection, all midstream urine samples were centrifuged at 1000 g for 10 min, spiked with sodium azide, de-identified, and stored at −80 °C until analysis.

In order to compare collagen levels in men with or without LUTS, human periurethral prostatic tissues were collected from a separate group of LUTS patients (n = 5) and age-matched controls (n = 7) assessed under AUASI criteria. Periurethral tissues were procured at surgery from men undergoing radical prostatectomy, who had completed the AUASI within 30 days before surgery. Patient clinical information was provided in Supplementary Table S2. Experimental details were described previously^3,31. Tissue samples and related clinical information were obtained with IRB approval.