Department of Pediatrics, Graduate School of Medicine, Yokohama City University.
Cardiovascular Research Institute, Yokohama City University.
Circ J. 2019 Feb 25;83(3):654-661. doi: 10.1253/circj.CJ-18-1033. Epub 2019 Feb 7.
Antenatal betamethasone (BMZ) is a standard therapy for reducing respiratory distress syndrome in preterm infants. Recently, some reports have indicated that BMZ promotes ductus arteriosus (DA) closure. DA closure requires morphological remodeling; that is, intimal thickening (IT) formation; however, the role of BMZ in IT formation has not yet been reported.
First, DNA microarray analysis using smooth muscle cells (SMCs) of rat preterm DA on gestational day 20 (pDASMCs) stimulated with BMZ was performed. Among 58,717 probe sets, ADP-ribosyltransferase 3 (Art3) was markedly increased by BMZ stimulation. Quantitative reverse transcription polymerase chain reaction (RT-PCR) confirmed the BMZ-induced increase of Art3 in pDASMCs, but not in aortic SMCs. Immunocytochemistry showed that BMZ stimulation increased lamellipodia formation. BMZ significantly increased total paxillin protein expression and the ratio of phosphorylated to total paxillin. A scratch assay demonstrated that BMZ stimulation promoted pDASMC migration, which was attenuated byArt3-targeted siRNAs transfection. pDASMC proliferation was not promoted by BMZ, which was analyzed by a 5'-bromo-2'-deoxyuridine (BrdU) assay. Whether BMZ increased IT formation in vivo was examined. BMZ or saline was administered intravenously to maternal rats on gestational days 18 and 19, and DA tissues were obtained on gestational day 20. The ratio of IT to tunica media was significantly higher in the BMZ-treated group.
These data suggest that antenatal BMZ administration promotes DA IT through Art3-mediated DASMC migration.
产前倍他米松（BMZ）是治疗早产儿呼吸窘迫综合征的标准疗法。最近，一些报告表明 BMZ 可促进动脉导管未闭（DA）闭合。DA 闭合需要形态重塑，即内膜增厚（IT）形成；然而，BMZ 在 IT 形成中的作用尚未报道。
首先，对孕 20 天（pDASMCs）大鼠早产 DA 的平滑肌细胞（SMCs）进行了 BMZ 刺激的 DNA 微阵列分析。在 58717 个探针集中，ADP-核糖基转移酶 3（Art3）被 BMZ 刺激显著增加。定量逆转录聚合酶链反应（RT-PCR）证实了 BMZ 诱导的 pDASMCs 中 Art3 的增加，但在主动脉 SMCs 中没有。免疫细胞化学显示 BMZ 刺激增加了片状伪足的形成。BMZ 显著增加了总 paxillin 蛋白表达和磷酸化与总 paxillin 的比值。划痕实验表明，BMZ 刺激促进了 pDASMC 的迁移，而 Art3 靶向 siRNA 转染则减弱了这种迁移。BMZ 刺激并未促进 pDASMC 增殖，通过 5'-溴-2'-脱氧尿苷（BrdU）分析得出了这一结果。体内实验检查了 BMZ 是否增加 IT 形成。在孕 18 天和 19 天，通过静脉给予母体大鼠 BMZ 或生理盐水，并在孕 20 天获取 DA 组织。BMZ 处理组的 IT 与中膜的比值显著升高。
这些数据表明，产前 BMZ 给药通过 Art3 介导的 DASMC 迁移促进 DA IT 的形成。
