Human amniotic epithelial cells promote diabetic wound healing by inhibiting neutrophil extracellular traps

Abstract:

Objective Delayed diabetic wound healing is characterized by dysfunction of multiple cells and formation of neutrophil extracellular traps（NETs）. Previous studies demonstrated that human amniotic epithelial cells（hAECs） can promote diabetic wound healing through regulating fibroblasts，macrophages，and vascular endothelial cells. Whether hAECs have any impact on NETs remains unknown. Our research aims to clarify the effect of hAECs on NETs.Methods Wounds were created on the dorsa of streptozotocin（STZ）-induced diabetic rat models. The wounds were treated with hAECs suspension or PBS and then observed for healing rates on days 5 and 10. Meanwhile，NETs-related biomarkers in the wound tissue were measured. Human neutrophils were extracted and stimulated with phorbol 12-myristate 13-acetate to establish an in vitro model of NETs. The neutrophils were then treated with conditioned medium for human amniotic epithelial cells（CM-hAECs） at 24 and 48 h to observe its impact on NETs production.Results The wound healing rates were significantly higher for wounds treated with hAECs suspension than for those treated with PBS on days 5［（32.61±2.48）% vs.（20.80±2.70）%，P=0.028］ and 10 ［（86.35±0.92）% vs.（61.52±3.70）%，P<0.001］，with an optimal concentration of 5×10⁵/mL. The hAECs suspension-treated group had reduced expression of NETs-related proteins Cit-H₃ and NE in the wound tissue on days 5 and 10. The in vitro study showed that CM-hAECs can inhibit NETs production.Conclusion This study suggests that hAECs may promote diabetic wound healing by inhibiting NETs production.