Clinical and Translational Research Center, Shanghai First Maternity and Infant Hospital, Tongji University School of Medicine, Shanghai, P. R. China.
J Hypertens. 2021 Aug 1;39(8):1642-1651. doi: 10.1097/HJH.0000000000002837.
Preeclampsia is a pregnancy-specific disorder that is a major cause of maternal and foetal morbidity and mortality, with a prevalence of 6-8% of pregnancies. Although the downregulation of lysyl oxidase (LOX) and LOX-like protein 2 (LOXL2), which leads to reduced trophoblast cell migration and invasion through activation of the TGF-β1/Smad3/collagen pathway, is relevant to preeclampsia, the mechanisms regulating differences in the gene expression of LOX and LOXL2 in placentas are not yet understood. This study aimed to investigate the mechanisms regulating differences in the gene expression of LOX and LOXL2 in placentas.
The expression of miRNAs, LOX and LOXL2 in preeclamptic placentas and control placentas was analysed by qPCR. Localisation of miR29a and LOXL2 in preeclamptic placentas was performed by RNA-Fluorescence in-situ hybridization assay. The direct regulation of LOXL2 by miR-29a was assessed by dual-luciferase reporter assays in human extravillous trophoblast cells (HTR8/SVneo). Cell migration and invasion were evaluated by Transwell assays in HTR8/SVneo cells.
miR-29a expression was upregulated in preeclamptic placentas and negatively correlated with LOXL2 mRNA expression levels. RNA-Fluorescence in-situ hybridization assay revealed a clear overlap between miR-29a and LOXL2 in the placentas of preeclampic women. LOXL2 was a direct target gene of miR-29a, as confirmed by a dual-luciferase reporter assay in HTR8/SVneo trophoblast cells. miR-29a suppressed HTR8/SVneo trophoblast cell migration and invasion. LOXL2 overexpression reversed the inhibitory effects of miR-29a on HTR8/SVneo trophoblast cell migration and invasion.
Our results suggest that the upregulation of miR-29a suppresses the migration and invasion of HTR8/SVneo trophoblast cells by directly targeting LOXL2 in preeclampsia.
子痫前期是一种妊娠特有的疾病，是孕产妇和胎儿发病率和死亡率的主要原因，其患病率为 6-8%的妊娠。尽管赖氨酰氧化酶（LOX）和赖氨酰氧化酶样蛋白 2（LOXL2）的下调与子痫前期有关，通过激活 TGF-β1/Smad3/胶原途径导致滋养细胞迁移和侵袭减少，但调节胎盘 LOX 和 LOXL2 基因表达差异的机制尚不清楚。本研究旨在探讨调节胎盘 LOX 和 LOXL2 基因表达差异的机制。
通过 qPCR 分析子痫前期胎盘和对照胎盘中小 miRNA、LOX 和 LOXL2 的表达。通过 RNA-荧光原位杂交测定子痫前期胎盘 miR29a 和 LOXL2 的定位。通过双荧光素酶报告基因测定在人绒毛外滋养细胞（HTR8/SVneo）中评估 LOXL2 受 miR-29a 的直接调节。通过 HTR8/SVneo 细胞中的 Transwell 测定评估细胞迁移和侵袭。
miR-29a 在子痫前期胎盘组织中表达上调，与 LOXL2 mRNA 表达水平呈负相关。RNA-荧光原位杂交测定显示 miR-29a 和 LOXL2 在子痫前期妇女的胎盘组织中明显重叠。LOXL2 是 miR-29a 的直接靶基因，这在 HTR8/SVneo 滋养细胞中通过双荧光素酶报告基因测定得到证实。miR-29a 抑制 HTR8/SVneo 滋养细胞的迁移和侵袭。LOXL2 过表达逆转了 miR-29a 对 HTR8/SVneo 滋养细胞迁移和侵袭的抑制作用。
我们的结果表明，miR-29a 的上调通过直接靶向 LOXL2 抑制子痫前期 HTR8/SVneo 滋养细胞的迁移和侵袭。
