Isolation and identification of urine-derived stem cells from female patients with interstitial cystitis/bladder pain syndrome

Objective To establish the method for isolation and culture of urine-derived stem cells (USCs) from female patients with interstitial cystitis/bladder pain syndrome(IC/BPS). Methods The USCs were collected from fresh midstream urine samples from 6 female IC/BPS patients admitted to our hospital from June 2018 to December 2018.The 6 patients were 33-55 years old (average 41.5 years old), and their course of illness was 2-18 years (average 8 years). The USCs were isolated from the urine through times of centrifugation and cultured in specific medium. Growth curve and cell cycle of USCs were observed.The expression of surface markers of USCs was analyzed by flow cytometry and immunofluorescence, the smooth muscle and epithelial differentiation potential of USCs were detected by immunofluorescence staining of surface markers of smooth muscle cells and epithelial cells. Results USCs were successfully extracted from 3 of 6 female patients, and the success rate reached 50% by once extraction.USCs showed a "rice-grain" spindle appearance and showed logarithmic growth. USCs expressed surface markers associated with mesenchymal stem cells( e. g. CD44, CD73, CD105, CD133) and embryonic stem cells [e.g. stage-specific embryonic antigen 4 (SSEA4)] and pericytes[e.g. CD146, platelet derived growth factor beta receptor (PDGFRB) and NG2], but didn’t express hematopoietic stem cell surface markers(e.g. CD31, CD34 and CD45). When induced to smooth muscle cells or epithelial cells, the cells expressed the surface markers of smooth muscle cells [e.g. desmin, myosin, alpha-smooth muscle actin(α-SMA) and vimentin ] and epithelial cells(e.g. uroplakin 1A, uroplakin 3B, AE1/AE3 and cytokeratin 13). Conclusions The method of isolation and culture of USCs from female IC/BPS patients was successfully established, and it provides a preliminary technical method for exploring the application of USCs in the clinical study of IC/BPS patients with autologous treatment. Key words: Cystitis, interstitial; Bladder pain syndrome; Urine; Stem Cells; Isolation; Identification