Human umbilical cord mesenchymal stem cells ameliorates cisplatin-induced blood-testis barrier dysfunction in mice by mitigating ferroptosis.

BACKGROUND: Cisplatin (CDDP), a widely used chemotherapeutic agent, induces reproductive toxicity primarily by damaging the blood-testis barrier (BTB) and triggering oxidative stress. This study aimed to investigate whether human umbilical cord mesenchymal stem cells (hUC-MSCs) protect against CDDP-induced BTB dysfunction and ferroptosis in mice, with implications for preserving fertility in chemotherapy patients. METHODS: Male C57 mice were randomized into four groups: control, CDDP-treated, hUC-MSCs-treated, and CDDP+hUC-MSCs-treated. An additional CDDP+Ferrostatin-1 (Fer-1, a ferroptosis inhibitor) group was included to validate ferroptosis involvement. Testicular histology, sperm quality, BTB integrity (via Evans blue permeability assay), and oxidative stress markers were evaluated. Ferroptosis-related (GPX4, NRF2, COX2, TFR1) and BTB-related (N-cadherin, ZO-1, Connexin 43) proteins were assessed by immunofluorescence and Western blotting. In vitro fertilization (IVF) was used to evaluate fertility. RESULTS: CDDP induced significant testicular damage, reduced sperm quality, increased BTB permeability, and disrupted BTB proteins. It also triggered ferroptosis, as evidenced by decreased GSH, elevated MDA, downregulated GPX4/NRF2, and upregulated COX2/TFR1. hUC-MSCs reversed these changes: restoring GSH levels, reducing MDA, normalizing ferroptosis-related proteins, and repairing BTB integrity. Fer-1 mimicked these effects, confirming ferroptosis as a key mechanism. IVF showed hUC-MSCs restored embryonic development (two-cell and blastocyst rates) to normal. CONCLUSIONS: hUC-MSCs protect against CDDP-induced reproductive injury by inhibiting ferroptosis (especially in Sertoli cells), repairing BTB, and restoring fertility. Their transient retention and low immunogenicity support their potential as a safe therapeutic strategy for preserving fertility in chemotherapy patients.