Sal-hDPSCs Transplantation Alleviates Hypoxic-Ischaemic Ferroptosis in Neonatal Rats Via the FSP1-CoQ<sub>10</sub> Axis.

Abstract

<h4>Objective</h4>To investigate the therapeutic effects and mechanisms of salidroside-pretreated human dental pulp stem cells (Sal-hDPSCs) on hypoxic-ischaemic brain damage (HIBD) in neonatal rats, providing a scientific basis for clinical application of hDPSCs.<h4>Methods</h4>An oxygen-glucose deprivation (OGD) model was established in hDPSCs. Cell viability and migration were assessed by CCK-8 and wound healing assays. The HIBD model was induced in neonatal rats using the Rice-Vannucci method and at 24 hours post-induction, hDPSCs or Sal-hDPSCs were transplanted. At 72 hours post-transplantation, cortical pathology was examined by HE and Nissl staining; Fe²⁺, malondialdehyde (MDA), superoxide dismutase (SOD) and CoQ₁₀ levels were measured; mitochondrial morphology was observed by transmission electron microscopy; and glutathione peroxidase 4 (GPX4)/ferroptosis suppressor protein 1 (FSP1) expression was detected by immunofluorescence and Western blot. Neurobehavioural function was evaluated at 28 days using novel object recognition and mesh tests. In PC12 cells subjected to OGD, the effects of conditioned medium from hDPSCs or Sal-hDPSCs, with or without the FSP1 inhibitor iFSP1, were assessed by measuring Fe²⁺, MDA, reactive oxygen species, CoQ₁₀ and GPX4/FSP1 expression.<h4>Results</h4>Sal pretreatment (20 μM) significantly enhanced hDPSC viability and migration after OGD. In HIBD rats, neuronal damage, elevated Fe²⁺ and MDA decreased SOD activity, reduced GPX4/FSP1 expression and CoQ₁₀ level and typical ferroptotic mitochondrial changes were observed. Both hDPSCs and Sal-hDPSCs transplantation improved these alterations, with Sal-hDPSCs showing greater efficacy. Neurobehavioural outcomes were also significantly improved in the treatment groups. In vitro, Sal-hDPSCs-CM markedly reduced Fe²⁺, MDA and reactive oxygen species, upregulated GPX4/FSP1 and increased CoQ₁₀ in OGD-exposed PC12 cells; these effects were abolished by iFSP1.<h4>Conclusion</h4>Sal pretreatment enhances the survival and migratory capacity of hDPSCs under hypoxic-ischaemic conditions, thereby improving their therapeutic efficacy. Moreover, Sal-hDPSCs alleviate HIBD by inhibiting ferroptosis via the FSP1-CoQ₁₀ axis.