Exploring the Mechanisms of Microenergy Acoustic Pulse Therapy for the Treatment of Female Stress Urinary Incontinence—Part II

Aims: While previous studies showed that micro-energy acoustic pulse (MAP) therapy restores urethral structure and function in adult stress urinary incontinence (SUI) rats, the underlying mechanisms remain unclear. This study aimed to explore the effect of MAP therapy in a rat model of vaginal birth injury-induced SUI at single cell resolution. Methods: Rat model of SUI was established using vaginal balloon dilation plus ovariectomy combined with β-aminopropionitrile treatment. Subsequently, MAP therapy was administered twice weekly for a total of 4 weeks. At the end of the treatment, single-cell sequencing was performed to analyze changes of cell heterogeneity and signaling in the urethral tissue microenvironment. Functional evaluations, including leak point pressure (LPP) measurements, electromyography, and electrophysiological studies, were conducted to confirm the effects of MAP therapy on urethral repair and muscle reinnervation. Results: MAP enhanced the transcription levels of various cell proliferation markers, including Pcna, Mki67, and Ccne2. The MAP treatment group exhibited higher muscle fiber content and structural integrity in the urethral sphincter compared to the untreated SUI model group. MAP also improved LPP, reduced sudden jumps in the CMAP value, and activated pathways such as “ribosome” in muscle cells. Additionally, MAP reduced senescence-associated beta-galactosidase levels in the urethral epithelium and influenced the expression of multiple transcription factors. Conclusions: MAP therapy effectively promotes urethral repair by modulating cellular aging and improving muscle reinnervation. These findings provide valuable insights into urethral repair mechanisms and lay the groundwork for developing novel therapies for SUI. Clinical Trial Registration: This study is based on an animal model and does not require a clinical trial registration.