人羊膜上皮细胞通过抑制中性粒细胞胞外诱捕网促进糖尿病创面愈合

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

摘要:

目的 糖尿病创面愈合延迟的特征是多细胞功能障碍及中性粒细胞胞外诱捕网（neutrophil extracellular traps，NETs）的形成。既往研究表明人羊膜上皮细胞（human amniotic epithelial cells，hAECs）可通过调节成纤维细胞、巨噬细胞和血管内皮细胞促进糖尿病创面愈合。但hAECs对NETs是否有影响仍不得而知。本研究旨在阐明hAECs对NETs的影响。方法 体内：糖尿病大鼠模型通过链脲佐菌素（streptozotocin，STZ）诱导，在背部建立创面，用hAECs混悬液或PBS（Phosphate buffered saline）对创面进行干预后观察第5和第10天的愈合率，同时检测创面组织NETs相关的生物标志物。体外：提取人中性粒细胞，并用佛波醇（phorbol 12-myristate 13-acetate，PMA）刺激，建立体外NETs模型。分别用24、48 h人羊膜上皮细胞的条件培养基（conditioned medium for human amniotic epithelial cells，CM-hAECs）干预中性粒细胞，观察其对NETs生成的作用。结果 在第5和第10天，hAECs细胞混悬液干预的创面愈合率均显著高于PBS干预的创面［（32.61±2.48）% vs.（20.80±2.70）%，P=0.028；（86.35±0.92）% vs.（61.52±3.70）%，P<0.001］，且最佳浓度为5×10⁵个/mL。hAECs细胞混悬液干预组创面组织中NETs相关蛋白组蛋白3（citrullinated histone，Cit-H₃）和中性粒细胞弹性蛋白酶（neutrophil elastase，NE）的表达在第5天和第10天降低。体外研究表明，hAECs的条件培养基可抑制NETs的生成。结论 hAECs可能通过抑制NETs的生成促进糖尿病创面的愈合。

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.