Tarui Tomo, Kim Aimee, Flake Alan, McClain Lauren, Stratigis John D, Fried Inbar, Newman Rebecca, Slonim Donna K, Bianchi Diana W
Mother Infant Research Institute, Pediatrics, Floating Hospital for Children, Tufts Medical Center, Boston, MA.
Center for Fetal Research, Pediatric Surgery, Children's Hospital of Philadelphia, Philadelphia, PA.
Am J Obstet Gynecol. 2017 Nov;217(5):587.e1-587.e10. doi: 10.1016/j.ajog.2017.07.022. Epub 2017 Jul 20.
Cell-free RNA in amniotic fluid supernatant reflects developmental changes in gene expression in the living fetus, which includes genes that are specific to the central nervous system. Although it has been previously shown that central nervous system-specific transcripts are present in amniotic fluid supernatant, it is not known whether changes in the amniotic fluid supernatant transcriptome reflect the specific pathophysiologic condition of fetal central nervous system disorders. In myelomeningocele, there is open communication between the central nervous system and amniotic fluid.
The purpose of this study was to identify molecular pathophysiologic changes and novel disease mechanisms that are specific to myelomeningocele by the analysis of amniotic fluid supernatant cell-free RNA in fetuses with open myelomeningocele.
Amniotic fluid supernatant was collected from 10 pregnant women at the time of the open myelomeningocele repair in the second trimester (24.5±1.0 weeks); 10 archived amniotic fluid supernatant from sex and gestational age-matched euploid fetuses without myelomeningocele were used as controls (20.9±0.9 weeks). Differentially regulated gene expression patterns were analyzed with the use of human genome expression arrays.
Fetuses with myelomeningocele had 284 differentially regulated genes (176 up- and 108 down-regulated) in amniotic fluid supernatant. Known genes that were associated with myelomeningocele (PRICKLE2, GLI3, RAB23, HES1, FOLR1) and novel dysregulated genes were identified in association with neurodevelopment and neuronal regeneration (up-regulated, GAP43 and ZEB1) or axonal growth and guidance (down-regulated, ACAP1). Pathway analysis demonstrated a significant contribution of inflammation to disease and a broad influence of Wnt signaling pathways (Wnt1, Wnt5A, ITPR1).
Transcriptomic analyses of living fetuses with myelomeningocele with the use of amniotic fluid supernatant cell-free RNA demonstrated differential regulation of specific genes and molecular pathways relevant to this central nervous system disorder, which resulted in a new understanding of pathophysiologic changes. The data also suggested the importance of pathways that involve secondary disease, such as inflammation, in myelomeningocele. These newly identified pathways may lead to hypotheses that can test novel therapeutic targets as adjuncts to fetal surgical repair.
羊水上清液中的游离RNA反映了活胎儿基因表达的发育变化，其中包括中枢神经系统特有的基因。尽管此前已表明羊水上清液中存在中枢神经系统特异性转录本，但尚不清楚羊水上清液转录组的变化是否反映胎儿中枢神经系统疾病的特定病理生理状况。在脊柱裂合并脊髓脊膜膨出中，中枢神经系统与羊水之间存在开放的连通。
本研究的目的是通过分析开放性脊柱裂合并脊髓脊膜膨出胎儿的羊水上清液游离RNA，确定脊柱裂合并脊髓脊膜膨出特有的分子病理生理变化和新的疾病机制。
在孕中期开放性脊柱裂合并脊髓脊膜膨出修复时（24.5±1.0周），从10名孕妇收集羊水上清液；将10份来自性别和孕周匹配的非脊柱裂合并脊髓脊膜膨出的整倍体胎儿的存档羊水上清液用作对照（20.9±0.9周）。使用人类基因组表达阵列分析差异调节的基因表达模式。
脊柱裂合并脊髓脊膜膨出的胎儿羊水上清液中有284个差异调节基因（176个上调和108个下调）。鉴定出与脊柱裂合并脊髓脊膜膨出相关的已知基因（PRICKLE2、GLI3、RAB23、HES1、FOLR1）以及与神经发育和神经元再生（上调，GAP43和ZEB1）或轴突生长和导向（下调，ACAP1）相关的新的失调基因。通路分析表明炎症对疾病有显著贡献，且Wnt信号通路（Wnt1、Wnt5A、ITPR1）有广泛影响。
使用羊水上清液游离RNA对脊柱裂合并脊髓脊膜膨出的活胎儿进行转录组分析，显示了与这种中枢神经系统疾病相关的特定基因和分子通路的差异调节，这导致了对病理生理变化的新认识。数据还表明涉及继发性疾病（如炎症）的通路在脊柱裂合并脊髓脊膜膨出中的重要性。这些新确定的通路可能会产生可测试作为胎儿手术修复辅助手段的新治疗靶点的假设。
