Vizitiu Anda-Cornelia, Stambouli Danae, Pavel Anca-Gabriela, Muresan Maria-Cezara, Anastasiu Diana Maria, Bejinar Cristina, Alexa Anda, Marian Catalin, Sirbu Ioan Ovidiu, Sima Laurentiu
Doctoral School, Victor Babes University of Medicine and Pharmacy Timisoara, Eftimie Murgu Nr. 2, Timisoara 300041, Romania.
CytoGenomic Medical Laboratory, Calea Floreasca Nr. 35, Sector 1, Bucharest 014451, Romania.
Medicina (Kaunas). 2019 Nov 7;55(11):728. doi: 10.3390/medicina55110728.
Although Down syndrome is the most frequent aneuploidy, its pathogenic molecular mechanisms are not yet fully understood. The aim of our study is to quantify-by qRT-PCR-the expression levels of both the mature forms and the pri-miRNAs of the microRNAs resident on chromosome 21 (miR(21)) in the amniotic fluid samples from Down syndrome singleton pregnancies and to estimate the impact of the differentially expressed microRNAs on Down syndrome fetal heart and amniocytes transcriptomes. We collected amniotic fluid samples harvested by trained obstetricians as part of the second trimester screening/diagnostic procedure for aneuploidies to assess the trisomy 21 status by QF-PCR and karyotyping. Next, we evaluated-by Taqman qRT-PCR-the expression levels of both the mature forms and the pri-miRNA precursors of the microRNAs resident on chromosome 21 in amniotic fluid samples from singleton Down syndrome and euploid pregnancies. Further, we combined miRWalk 3.0 microRNA target prediction with GEO DataSets analysis to estimate the impact of hsa-miR-99a abnormal expression on Down syndrome heart and amniocytes transcriptome. We found a statistically significant up-regulation of the mature form of miR-99a, but not pri-miR-99a, in the amniotic fluid samples from Down syndrome pregnancies with female fetuses. GATHER functional enrichment analysis of miRWalk3.0-predicted targets from Down syndrome amniocytes and fetal hearts transcriptome GEODataSets outlined both focal adhesion and cytokine-cytokine receptor interaction signaling as novel signaling pathways impacted by miR-99a and associated with cardiac defects in female Down syndrome patients. The significant overexpression of miR-99a, but not pri-miR-99a, points towards an alteration of the post-transcriptional mechanisms of hsa-miR-99a maturation and/or stability in the female trisomic milieu, with a potential impact on signaling pathways important for proper development of the heart.
尽管唐氏综合征是最常见的非整倍体疾病，但其致病分子机制尚未完全明确。我们研究的目的是通过定量逆转录聚合酶链反应（qRT-PCR），测定唐氏综合征单胎妊娠羊水样本中21号染色体上微小RNA（miR(21)）的成熟形式和初级微小RNA（pri-miRNAs）的表达水平，并评估差异表达的微小RNA对唐氏综合征胎儿心脏和羊膜细胞转录组的影响。我们收集了由训练有素的产科医生采集的羊水样本，作为孕中期非整倍体筛查/诊断程序的一部分，通过QF-PCR和核型分析评估21三体状态。接下来，我们通过Taqman qRT-PCR评估了唐氏综合征单胎妊娠和整倍体妊娠羊水样本中21号染色体上微小RNA的成熟形式和初级微小RNA前体的表达水平。此外，我们将miRWalk 3.0微小RNA靶标预测与GEO数据集分析相结合，以评估hsa-miR-99a异常表达对唐氏综合征心脏和羊膜细胞转录组的影响。我们发现，在怀有女胎的唐氏综合征妊娠羊水样本中，miR-99a的成熟形式有统计学意义的上调，但pri-miR-99a没有上调。对唐氏综合征羊膜细胞和胎儿心脏转录组GEO数据集的miRWalk3.0预测靶标的GATHER功能富集分析表明，粘着斑和细胞因子-细胞因子受体相互作用信号通路是受miR-99a影响的新信号通路，与女性唐氏综合征患者的心脏缺陷有关。miR-99a而非pri-miR-99a的显著过表达表明，在女性三体环境中，hsa-miR-99a成熟和/或稳定性的转录后机制发生了改变，这可能对心脏正常发育的重要信号通路产生影响。
