Human Amniotic Epithelial Stem Cells Promote Functional Recovery After Spinal Cord Injury In Rats By Regulating The Polarization Of Macrophages.

Spinal cord injury (SCI) is a catastrophic nerve injury caused by extremely severe damage to the spinal cord, for which effective treatments are currently unavailable. Human amniotic epithelial stem cells (hAESCs) are considered promising candidates for transplantation in various clinical and preclinical applications, due to their lack of limitations such as ethical barriers, immune rejection, tumorigenicity, or cell origin. Nevertheless, the effectiveness and mechanism by which hAESCs treat SCI remain elusive. To assess the motor function recovery process following SCI in rats, the Basso Beattie Bresnahan (BBB) behavior test, inclined plate scale and motor evoked potential (MEP) analysis were used in this study after transplantation of hAESCs at different doses. And the underlying mechanism was investigated by histological and molecular methods. The transplantation of hAESCs can significantly promote the recovery of motor function in SCI group, and the higher the dose, the better the effect. Compared with SCI group, hAESCs group had reduced tissue damage, significantly increased the number of neurons, neurofilaments and myelin sheath, and significantly reduced syringomyelia and glial scars. In addition, hAESCs inhibited the Levels of tumor necrosis factor (TNF-α) and interleukin-6 (IL-6) and increased the expression of the interleukin-4 (IL-4), interleukin-10 (IL-10) and interleukin-13 (IL-13), and promoted the shift of M1-polarized macrophages to M2-polarized macrophages. Our results demonstrate that hAESCs promoted the recovery of motor function after SCI by promoting M2 polarization of macrophages and reducing neuroinflammation. These findings may provide novel therapeutic strategies for SCI.