The Nerve-Induced Adipose Stem Cells Promote Nerve Repair in Stress Urinary Incontinence by Regulating Schwann Cell Repair Phenotype Conversion Through Activation of the Notch Pathway.

Abstract

Stress urinary incontinence (SUI) currently lacks effective treatment options, and the restoration of neurological function remains a major challenge, with unmet clinical needs. Research has indicated that adipose-derived stem cells (ADSCs) can be induced to differentiate into neural-induced adipose-derived stem cells (NI-ADSCs) under specific inductive conditions, exhibiting excellent neuroregenerative capabilities. ADSCs were obtained from female SD rats and induced into NI-ADSCs. In vitro, NI-ADSCs were co-cultured with Schwann cells (SCs) to investigate their effects on SC proliferation and repair phenotype transition and further explore its underlying mechanism. In vivo, a rat model of SUI was established using a bilateral pudendal nerve transection method. NI-ADSCs were injected into the urethral sphincter to evaluate their effects on urodynamics, muscle angiogenesis, and neural repair in SUI rats, while also exploring the mechanisms of neural repair. This study used EGF, FGF, and B27 to induce ADSCs into NI-ADSCs expressing neural induction markers (MAP, Nestin, and PAX6). In vitro experiments found no significant difference in the proliferation of L6 and RSC96 between NI-ADSCs and ADSCs (p > 0.05). However, when co-cultured with NI-ADSCs, SCs showed upregulated expression of repair-related phenotypic markers (BDNF, GDNF, and GFAP). In this phenotypic transformation process, the expression of Notch-related pathway proteins (Notch1, NICD, and Hes1) was increased, and the use of DAPT (a Notch pathway inhibitor) could suppress the SC repair phenotype transformation. In vivo, experiments revealed that intraurethral injection of NI-ADSCs significantly promoted the expression of neural marker (S100β) and demyelination markers (GFAP) and urodynamic recovery in SUI rats, while DAPT inhibited its neural repair effect. In summary, our study demonstrates that NI-ADSCs can promote nerve regeneration by promoting and maintaining the repair-related phenotype of SCs. The underlying mechanism may be related to the activation of the Notch signaling pathway.