Department of Obstetrics and Gynecology, Louisiana State University Health Sciences Center - Shreveport, LA, 71103, United States; Department of Obstetrics and Gynecology, Second Affiliated Hospital, Harbin Medical University, Harbin, 150086, China.
Department of Obstetrics and Gynecology, Louisiana State University Health Sciences Center - Shreveport, LA, 71103, United States.
J Reprod Immunol. 2021 Apr;144:103281. doi: 10.1016/j.jri.2021.103281. Epub 2021 Feb 1.
MiR-126-3p is a prototype of an endothelial miRNA and has protective effects on endothelial cells. However, little is known about the effects of miR-126-3p on placental trophoblasts. In the present study, we tested the hypothesis that aberrant miR-126-3p expression is present in preeclamptic placenta which contributes to increased inflammatory response in trophoblasts. Placentas were obtained immediately after delivery from normotensive and preeclamptic pregnancies. Villous tissue was either fixed with formalin or used for trophoblast isolation. Trophoblast miR-126-3p expression was assessed by in situ hybridization of formalin-fixed tissue sections and by RT-PCR in cultured syncytiotrophoblasts. Culture medium was collected for measurement of IL-6, TNFα, and 8-Isoprostane production by ELISA and total cellular protein was collected for evaluation of HIF1α expression by Western blot. Effects of overexpression of miR-126-3p in trophoblasts on cytokine production were tested by transfection of pre-mir-126, a precursor of miR-126, into primary isolated trophoblasts. We found that downregulation of miR-126-3p expression was associated with increased IL-6 and TNFα production in trophoblasts from preeclamptic placentas vs. normal placentas. Moreover, transient overexpression of miR-126-3p significantly reduced IL-6 and TNFα production in trophoblasts from both normal and preeclamptic placentas. We further found that increase in miR-126-3p expression not only suppressed hypoxia-induced increases in IL-6 and TNFα production, but also attenuated hypoxia-induced increases in HIF1α expression and 8-Isoprostane production in trophoblasts cultured under hypoxic condition. These results provide plausible evidence that downregulation of miR-126-3p expression reduces anti-inflammatory and anti-oxidative stress activities in placental trophoblasts in preeclampsia.
miR-126-3p 是内皮细胞 microRNA 的原型，对内皮细胞具有保护作用。然而，miR-126-3p 对胎盘滋养层的影响知之甚少。本研究旨在验证假设，即子痫前期胎盘存在异常 miR-126-3p 表达，导致滋养层炎症反应增加。分娩后立即从正常妊娠和子痫前期孕妇中获得胎盘。绒毛组织用福尔马林固定或用于滋养层分离。通过福尔马林固定组织切片的原位杂交和培养的合体滋养层的 RT-PCR 评估滋养层 miR-126-3p 表达。通过 ELISA 测量培养上清液中 IL-6、TNFα 和 8-异前列腺素的产生，收集总细胞蛋白通过 Western blot 评估 HIF1α 的表达。通过转染前 miR-126（miR-126 的前体）到原代分离的滋养层中来测试 miR-126-3p 过表达对细胞因子产生的影响。我们发现，与正常胎盘相比，子痫前期胎盘滋养层 miR-126-3p 表达下调与 IL-6 和 TNFα 产生增加有关。此外，miR-126-3p 的瞬时过表达显著降低了正常和子痫前期胎盘滋养层中 IL-6 和 TNFα 的产生。我们进一步发现，miR-126-3p 表达增加不仅抑制了缺氧诱导的 IL-6 和 TNFα 产生增加，而且减轻了缺氧诱导的 HIF1α 表达和缺氧条件下培养的滋养层中 8-异前列腺素产生增加。这些结果为 miR-126-3p 表达下调降低子痫前期胎盘滋养层抗炎和抗氧化应激活性提供了合理的证据。
