Previously, we revealed sexually dimorphic mRNA expression and responsiveness to maternal dietary supplementation with n-3 long-chain polyunsaturated fatty acids (LCPUFA) in placentas from a defined INFAT study subpopulation. Here, we extended these analyses and explored the respective placental microRNA expression, putative microRNA-mRNA interactions, and downstream target processes as well as their associations with INFAT offspring body composition. We performed explorative placental microRNA profiling, predicted microRNA-mRNA interactions by bioinformatics, validated placental target microRNAs and their putative targets by RT-qPCR and western blotting, and measured amino acid levels in maternal and offspring cord blood plasma and placenta. microRNA, mRNA, protein, and amino acid levels were associated with each other and with offspring body composition from birth to 5 years of age. Forty-six differentially regulated microRNAs were found. Validations identified differential expression for microRNA-99a (miR-99a) and its predicted target genes mTOR, SLC7A5, encoding L-type amino acid transporter 1 (LAT1), and SLC6A6, encoding taurine transporter (TauT), and their prevailing significant sexually dimorphic regulation. Target mRNA levels were mostly higher in placentas from control male than from female offspring, whereas respective n-3 LCPUFA responsive target upregulation was predominantly found in female placentas, explaining the rather balanced expression levels between the sexes present only in the intervention group. LAT1 and TauT substrates tryptophan and taurine, respectively, were significantly altered in both maternal plasma at 32 weeks’ gestation and cord plasma following intervention, but not in the placenta. Several significant associations were observed for miR-99a, mTOR mRNA, SLC7A5 mRNA, and taurine and tryptophan in maternal and cord plasma with offspring body composition at birth, 1 year, 3 and 5 years of age. Our data suggest that the analyzed targets may be part of a sexually dimorphic molecular regulatory network in the placenta, possibly modulating gene expression per se and/or counteracting n-3 LCPUFA responsive changes, and thereby stabilizing respective placental and fetal amino acid levels. Our data propose placental miR-99, SLC7A5 mRNA, and taurine and tryptophan levels in maternal and fetal plasma as potentially predictive biomarkers for offspring body composition.

中文翻译：

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胎儿性别调节胎盘 microRNA 表达、潜在的 microRNA-mRNA 相互作用以及氨基酸转运蛋白表达和底物的水平：妊娠期间 n-3 LCPUFA 干预的 INFAT 研究亚群分析以及与后代身体成分的关联

以前，我们揭示了来自定义的 INFAT 研究亚群的胎盘中的性二态性 mRNA 表达和对母体膳食补充剂 n-3 长链多不饱和脂肪酸 (LCPUFA) 的反应。在这里，我们扩展了这些分析并探讨了各自的胎盘 microRNA 表达、假定的 microRNA-mRNA 相互作用和下游目标过程以及它们与 INFAT 后代身体成分的关联。我们进行了探索性胎盘 microRNA 分析，通过生物信息学预测了 microRNA-mRNA 相互作用，通过 RT-qPCR 和蛋白质印迹验证了胎盘靶 microRNA 及其推定的靶标，并测量了母体和后代脐带血浆和胎盘中的氨基酸水平。微RNA、mRNA、蛋白质、和氨基酸水平相互关联，并与从出生到 5 岁的后代身体成分相关。发现了 46 个差异调节的 microRNA。验证确定了 microRNA-99a (miR-99a) 及其预测的靶基因 mTOR、SLC7A5、编码 L 型氨基酸转运蛋白 1 (LAT1) 和 SLC6A6、编码牛磺酸转运蛋白 (TauT) 的差异表达，以及它们普遍存在的显着性二态性规定。对照雄性胎盘中的目标 mRNA 水平大多高于雌性后代，而相应的 n-3 LCPUFA 响应性目标上调主要在雌性胎盘中发现，这解释了仅在干预组中存在的性别之间相当平衡的表达水平。LAT1 和 TauT 底物分别是色氨酸和牛磺酸，妊娠 32 周时的母体血浆和干预后的脐带血浆中的 β 显着改变，但在胎盘中没有显着改变。观察到 miR-99a、mTOR mRNA、SLC7A5 mRNA 以及母体和脐带血浆中的牛磺酸和色氨酸与后代在出生、1 岁、3 和 5 岁时的身体成分存在显着关联。我们的数据表明，分析的目标可能是胎盘中性二态分子调控网络的一部分，可能调节基因表达本身和/或抵消 n-3 LCPUFA 响应变化，从而稳定各自的胎盘和胎儿氨基酸水平。我们的数据表明，母体和胎儿血浆中的胎盘 miR-99、SLC7A5 mRNA 以及牛磺酸和色氨酸水平可作为后代身体成分的潜在预测生物标志物。