Amniotic fluid stem cells alleviate neuronal injury-related changes in spina bifida by inducing autophagy via regulating the FOXO1/STAT3 axis.

Abstract

Spina bifida (SB) is associated with progressive spinal cord injury and limited therapeutic options for neural protection. Amniotic fluid stem cells (AFSCs) have shown regenerative potential, but their effects on SB-related neuronal injury and the underlying mechanisms remain unclear. In this study, we investigated whether AFSCs alleviate neuronal injury-related changes in SB rats through the modulation of autophagy via the FOXO1/STAT3 pathway. SB-like lesions were induced in neonatal rats, followed by the intramedullary injection of AFSCs or vehicle on postnatal day 1. Behavioral assessment was performed using Basso, Beattie, and Bresnahan locomotor scoring on days 2, 7, and 14 after injection, and lesion-centered lumbosacral spinal cord tissues were collected on day 15. AFSC treatment partially improved hindlimb locomotor scores and reduced neuronal injury-related alterations in SB rats. AFSCs also increased autophagy-associated markers, including LC3II/I and Beclin1, and reduced p62 mRNA expression in vivo and in neural stem cells isolated from SB rats. Mechanistically, AFSC treatment was associated with reduced FOXO1 and enhanced STAT3 signaling. FOXO1 overexpression or STAT3 inhibition attenuated AFSC-mediated effects, whereas siRNA-mediated FOXO1 knockdown enhanced these effects; combined STAT3 knockdown partially reversed the effects of FOXO1 silencing. These findings suggest that AFSCs alleviate SB-related neuronal injury-associated changes by regulating autophagy through the FOXO1/STAT3 axis. This study provides preclinical evidence for an experimental neuroprotective mechanism of AFSCs, although further validation is required before translational applicability can be considered.