Introduction: Urethral stricture is characterized by urethral lumen narrowing due to fibrosis. Urethroplasty of the urethral stricture involves excision of scar, and may be followed by reconstruction of the urethra using split-thickness skin, buccal mucosa, urethral mucosa or, more recently, tissue-engineered grafts. The stricture wound healing process after urethroplasty is known to be mediated by an interaction between keratinocyte and fibroblasts; however, the underlying mechanisms are not studied in detail yet. We investigated the influence of epithelial cell-conditioned medium (ECCM) (obtained from confluent penile skin, buccal mucosa and urethral cell cultures) on the proliferation and migration of stricture fibroblasts using an in vitro scratch assay.
Materials and methods: ECCM was collected from confluent primary epithelial cell cultures of three different human biopsies (penile skin, buccal mucosa and urethral mucosa), whereas stricture fibroblasts were isolated from human urethral stricture biopsies. The effect of ECCM on stricture fibroblasts' proliferation and migration into the scratch was observed using a standard in vitro scratch assay over a period of 3 days. Four experiments were performed independently using four stricture fibroblasts from four patients and ECCM was collected from 12 different patients' primary cell cultures.
Results: ECCM from primary epithelial cells cultures obtained from penile skin, buccal mucosa and urethra inhibited stricture fibroblasts' proliferation and migration in the in vitro scratch assay.
Conclusion: These results demonstrate the ability of ECCM to inhibit the proliferation and migration of stricture fibroblasts and present it as an effective adjunct in urethroplasty, which may influence stricture wound healing and inhibit the recurrence of stricture.
Keywords: Epithelial cell-conditioned medium; scratch assay; tissue-engineered epithelial cell graft; urethral stricture; urethroplasty; wound healing.