Table_1_Neutrophil depletion in the pre-implantation phase impairs pregnancy index, placenta and fetus development.docx

Maternal neutrophils cells are players in gestational tolerance and fetus delivery. Nonetheless, their actions in each phase of the pregnancy are unknown. We here investigated the role of maternal neutrophil depletion before the blastocyst implantation phase and outcomes in the pregnancy index, placenta, and fetus development. Neutrophils were pharmacologically depleted by i.p. injection of anti-Gr1 (anti-neutrophils; 200 µg) 24 hours after plug visualization in allogeneic-mated C57BL/6/BALB/c mice. Depletion of peripheral neutrophils lasted until 48 hours after anti-Gr1 injection (gestational day 1.5-3.5). On gestational day 5.5, neutrophil depletion impaired the blastocyst implantation, as 50% of pregnant mice presented reduced implantation sites. On gestational day 18.5, neutrophil depletion reduced the pregnancy rate and index, altered the placenta disposition in the uterine horns, and modified the structure of the placenta, detected by reduced junctional zone, associated with decreased numbers of giant trophoblast cells, spongiotrophoblast. Reduced number of placenta cells labeled for vascular endothelial growth factor (VEGF), platelet-endothelial cell adhesion molecule (PECAM-1), and intercellular cell adhesion molecule (ICAM-1), important markers of angiogenesis and adhesiveness, were detected in neutrophil depleted mice. Furthermore, neutrophil depletion promoted a higher frequency of monocytes, natural killers, and T regulatory cells, and lower frequency of cytotoxic T cells in the blood, and abnormal development of offspring. Associated data obtained herein highlight the pivotal role of neutrophils actions in the early stages of pregnancy, and address further investigations on the imbricating signaling evoked by neutrophils in the trophoblastic interaction with uterine epithelium.

母体中性粒细胞细胞在妊娠耐受和胎儿分娩过程中扮演着重要角色。然而，它们在妊娠各阶段的具体作用尚不明确。本研究旨在探讨母体中性粒细胞在胚泡着床阶段之前的耗竭作用及其对妊娠指标、胎盘以及胎儿发育的影响。通过在异种交配的C57BL/6/BALB/c小鼠中，于插塞可视化后24小时通过腹腔注射抗Gr1抗体（抗中性粒细胞；200 µg）来药理性地耗竭中性粒细胞。外周中性粒细胞的耗竭持续至抗Gr1注射后48小时（妊娠第1.5-3.5天）。在妊娠第5.5天，中性粒细胞的耗竭影响了胚泡的着床，因为50%的妊娠小鼠表现出着床位点减少。在妊娠第18.5天，中性粒细胞的耗竭降低了妊娠率和指标，改变了子宫角中的胎盘分布，并影响了胎盘的结构，通过降低连接带以及与减少的巨滋养细胞和海绵滋养细胞的关联得到检测。在抗中性粒细胞耗竭的小鼠中，标记血管内皮生长因子（VEGF）、血小板内皮细胞粘附分子（PECAM-1）和细胞间粘附分子（ICAM-1）的胎盘细胞数量减少，这些是血管生成和粘附性的重要标志物。此外，中性粒细胞的耗竭促进了单核细胞、自然杀伤细胞和T调节细胞在血液中的频率增加，以及细胞毒性T细胞的频率降低，并导致后代发育异常。本研究获得的相关数据突出了中性粒细胞在妊娠早期阶段作用的至关重要性，并为进一步探讨中性粒细胞与子宫内膜上皮细胞相互作用所引发的复杂信号传导研究提供了依据。