黄芪多糖APS-Ⅱ-2对脂多糖所致绒毛膜羊膜炎诱发的肺泡化阻滞的改善作用

Effect of APS-Ⅱ-2 on intra-amniotic lipopolysaccharide-induced alveolarization arrest in bronchopulmonary dysplasia model rats

目的·探讨黄芪多糖APS-Ⅱ-2对脂多糖(lipopolysaccharide,LPS)所致绒毛膜羊膜炎诱发的肺泡化阻滞的改善作用及可能机制。方法·对孕16.5 d SD大鼠羊膜腔注射LPS,构建支气管肺发育不良模型。根据羊膜腔注入药物,将孕鼠随机分为对照组(Saline组)、LPS+Saline组、LPS+APS-Ⅱ-2组。LPS+APS-Ⅱ-2组新生鼠出生后第1~3日腹腔注射APS-Ⅱ-2溶液[50 mg/(kg·d)];Saline组和LPS+Saline组腹腔注射等体积生理盐水。取第1、3日新生鼠肺组织,苏木精-伊红(H-E)染色观察病理改变。SD大鼠骨髓巨噬细胞培养,分为PBS组、LPS+PBS组、LPS+APS-Ⅱ-2组,利用全转录组测序技术(RNA-sequence)筛选APS-Ⅱ-2抑制炎症的可能靶点。结果·APS-Ⅱ-2可改善新生鼠肺组织病理状态,LPS+APS-Ⅱ-2组大鼠出生第1日肺泡数较LPS+Saline组增多(P=0.033),第1、3日次级突起增多(P=0.002,P=0.026),第1、3日平均内衬间隔减小(P=0.006,P=0.004)。RNA-sequence结果显示APS-Ⅱ-2抑制一些炎症因子表达,如Toll样受体Tlr3、Tlr7、Tlr8;也促进一些有抗炎作用因子的表达,如花生四烯酸15-脂加氧酶Alox15和CD74。结论·APS-Ⅱ-2可通过调节炎症反应减轻LPS诱发的绒毛膜羊膜炎,进而改善支气管肺发育不良模型肺组织病理状态。

Objective · To investigate the role of APS-Ⅱ-2（a kind of plant-derived natural drug） on amelioration of chorioamnionitis-induced alveolarization arrest and the underlying mechanism. Methods · Bronchopulmonary dysplasia（BPD） model was constructed by intra-amniotic injection of lipopolysaccharide（LPS） in SD rats（E16.5）. The SD rats were randomly divided into control group（Saline group）、LPS model group（LPS＋Saline group） and APS-Ⅱ-2 administration group（LPS＋APS-Ⅱ-2 group）. Then neonatal rats in LPS＋APS-Ⅱ-2 group were given an intraperitoneal injection with APS-Ⅱ-2（50 mg/kg） for 3 consecutive days after birth, whereas rats in LPS＋Saline group and Saline group were administrated with an equal amount of normal saline. To examine pathologic change of pulmonary in neonatal rats, hematoxylin-eosin（H-E） staining was performed at postnatal day1 and 3. Then bone marrowderived macrophages（BMDMs） from SD rats were detected by the technology of RNA-sequence to research the immunomodulation of APS-Ⅱ-2. Results · APS-Ⅱ-2 administration group had drastically higher terminal air spaces（P=0.033 at postnatal day1） and secondary septa counts at postnatal day1 and 3, respectively（P=0.002, P=0.026） than LPS-induced model group, while mean linear intercept was the opposite situation at postnatal day1 and 3, respectively（P=0.006, P=0.004）. The detection of RNA-sequence indicated that APS-Ⅱ-2 suppressed the expression of inflammatory cytokines such as Tlr3, Tlr7 and Tlr8 in BMDMs. Meanwhile, it also promoted some pleiotropic cytokines with anti-inflammatory effects such as Alox15 and Cd74. Conclusion · Administration of APS-Ⅱ-2 could improve the pathology of BPD, thereby supporting the ethnopharmacological uses of the plant. This effect may be directly caused by modulatory effects of APS-Ⅱ-2 on inflammation.