Abstract：
Premature birth is a common obstetric complication but its pathogenesis is unclear. Inflammation at the maternal-fetal interface in preterm labor leads to the infiltration of neutrophils, which promotes inflammatory responses and induces the degradation of extracellular matrix and cell apoptosis, thus contributing to preterm labor. It is unclear whether neutrophil extracellular traps (NETs), a functional form of neutrophils, are involved in preterm labor.
After collecting amniotic membranes from research objects, we localized NETs by immunofluorescence and evaluated the expression of matrix metalloproteinase (MMP)-9 and MMP-2 by western blotting. Primary human amniotic epithelial cells (hAECs) subjected to treatment with NETs, 5-ethynyl-20-deoxyuridine cell proliferation assay, lactate dehydrogenase (LDH) assay, western blotting, and flow cytometry apoptosis assay were used to determine the effects of NETs on hAECs. We also elucidated possible mechanisms underlying the effects.
Compared with normal term women, NETs infiltration and MMP-9 expression in the amniotic membrane from preterm women had increased. Thereafter, NETs might suppress the proliferation and promote the apoptosis of hAECs. Furthermore, after NETs treatment, the mitochondrial membrane potential was significantly decreased, ERK1/2 phosphorylation expression was upregulated and reactive oxygen species (ROS) production was increased in hAECs. Changes in cell proliferation, LDH release, and cell apoptosis level due to NETs could be reversed by ROS inhibitor or ERK phosphorylation inhibitors.
NETs can promote the apoptosis of hAECs via ERK1/2 pathways dependent on ROS release.
After collecting amniotic membranes from research objects, we localized NETs by immunofluorescence and evaluated the expression of matrix metalloproteinase (MMP)-9 and MMP-2 by western blotting. Primary human amniotic epithelial cells (hAECs) subjected to treatment with NETs, 5-ethynyl-20-deoxyuridine cell proliferation assay, lactate dehydrogenase (LDH) assay, western blotting, and flow cytometry apoptosis assay were used to determine the effects of NETs on hAECs. We also elucidated possible mechanisms underlying the effects.
Compared with normal term women, NETs infiltration and MMP-9 expression in the amniotic membrane from preterm women had increased. Thereafter, NETs might suppress the proliferation and promote the apoptosis of hAECs. Furthermore, after NETs treatment, the mitochondrial membrane potential was significantly decreased, ERK1/2 phosphorylation expression was upregulated and reactive oxygen species (ROS) production was increased in hAECs. Changes in cell proliferation, LDH release, and cell apoptosis level due to NETs could be reversed by ROS inhibitor or ERK phosphorylation inhibitors.
NETs can promote the apoptosis of hAECs via ERK1/2 pathways dependent on ROS release.
摘要：
早产是常见的产科并发症，但其发病机制尚不清楚。早产中母胎界面的炎症导致中性粒细胞浸润，促进炎症反应，诱导细胞外基质降解和细胞凋亡，从而导致早产。目前尚不清楚中性粒细胞胞外诱捕网(NET)中性粒细胞的功能性形式，参与早产。
从研究对象中收集羊膜后，我们通过免疫荧光定位NETs，并通过蛋白质印迹评估基质金属蛋白酶（MMP）-9和MMP-2的表达。原代人羊膜上皮细胞（hAECs）用NET处理，5-乙炔基-20-脱氧尿苷细胞增殖试验，乳酸脱氢酶（LDH）测定，西方印迹,采用流式细胞仪检测细胞凋亡情况,以确定NETs对hAECs的影响。我们还阐明了影响的潜在机制。
与正常足月女性相比，早产妇女羊膜中的NETs浸润和MMP-9表达增加。此后,NETs可能抑制hAECs的增殖并促进其凋亡。此外，NETs治疗后，线粒体膜电位显著下降，hAECs中ERK1/2磷酸化表达上调，活性氧（ROS）产生增加。细胞增殖的变化，LDH释放,NETs引起的细胞凋亡水平可被ROS抑制剂或ERK磷酸化抑制剂逆转。
NETs可通过依赖ROS释放的ERK1/2通路促进hAECs凋亡。
从研究对象中收集羊膜后，
与正常足月女性相比，
NETs可通过依赖ROS释放的ERK1/2通路促进hAECs凋亡。
