LncRNA H19 Mediates MiR-let7e-5p Targeting MMP9 In The Pathogenesis Of Hypertensive Disorders Of Pregnancy

Objectives:Hypertensive disorders of pregnancy is an obstetric disease that seriously affects the outcome of mother and child.At present,it is believed that the ability of extravillous trophoblast infiltration was impaired,and "shallow placental implantation" was one of the causes of the disease.Long noncoding Ribonucleic Acid(lncRNA)H19 can promote the invasion of tumor cells.The formation process of placenta was similar to the process of tumor invasion.lncRNA H19 can regulate the expression of downstream target genes through micro RNA(miRNA)let7,while Matrix metalloproteinase9(MMP9)was involved in the decomposition of extracellular Matrix.It was related to cell invasion and migration.This study mainly explores whether lncRNA H19/miR-let7e-5p/MMP9,a molecular pathway regulating trophoblast invasion in the placenta,plays a role in the pathogenesis of hypertensive disorders of pregnancy.Methods:This study was divided into two parts.Part1 Experiment:Twenty cases of normal pregnancy and 86 cases of hypertensive disorders of pregnancy(HDP)hospitalized during the same period were enrolled,and the HDP patients were divided into 3 groups:Group Ⅰ included 26 cases of pregnancy induced hypertension(PIH),29 cases of mild preeclampsia(mPE)in group Ⅱ and 31 cases of severe preeclampsia(sPE)in group Ⅲ.sPE group included 8 cases of early onset sPE and 23 cases of late onset sPE.The placental tissues at delivery were collected,and the expression levels of lncRNA H19,miR-let7b-5p,miR-let7e-5p and MMP9 mRNA in samples from each patient were detected by qRT-PCR.Immunohistochemistry(IHC)was used to detect the expression level of MMP9 protein in placentae of different groups.Part2 Experiment:According to the results of Part1 experiment,miR-let7e-5p were screened out,which were related to disease development and had a stronger negative correlation with lncRNA H19,for subsequent studies to explore its mechanism of action.lncRNA H19 was knocked down and overexpressed,and the plasmids which overexpresed lncRNA H19 were co-transfected with miR-let7e-5p mimics in HTR-8/Svneo trophoblast cells.The expressions of lncRNA H19,miR-let7e-5p and MMP9 mRNA were detected by qRT-PCR.Cells invasion ability were detected by Transwell assay,cells migration ability were detected by cell scratch assay,and cells viability were detected by CCK8 assay.Results:1.The expression of lncRNA H19 was significantly increased in the placental tissues of PIH,mPE and sPE compared with the placental tissues of pregnant women with normal delivery.2.Compared with normal pregnancy,the expression of miR-let7b-5p was decreased in PIH,mPE and sPE placental tissues,the expression of miR-let7b-5p was lower in Early onset sPE than that in late onset sPE.3.Compared with normal pregnancy,the expression of miR-let7e-5p expression was decreased in PIH,mPE and sPE placental tissues.The expression of miR-let7e-5p was negatively correlated with lncRNA H19.4.Compared with normal pregnancy,the expression of MMP9 mRNA was decreased in PIH and sPE placenta tissues,However,there was no significant difference in the expression of MMP9 mRNA between mPE and the normal group.In the sPE group,the expression of MMP9 mRNA was lower in early onset sPE compared with that in the late onset sPE.5.The expression of MMP9 protein was decreased in PIH,mPE and sPE placental tissues compared with the normal group.6.After overexpress lncRNA H19 in HTR-8/Svneo cells,the expression of miR-let7e-5p was decreased,while the expression of MMP9 mRNA was increased,and the invasion and migration of trophoblast cells was enhanced.These result were reversed when lncRNA H19 was knocked down.7.The positive regulation of lncRNA H19 on the expression of MMP9 mRNA in the rescue group,which co-transfected overexpressed lncRNA H19 plasmids and miR-let7e-5p mimics in HTR-8/Svneo cells,was reversed by miR-let7e-5p,and the positive regulation of lncRNA H19 on the invasion and migration of trophoblast cells was also reversed by miR-let7e-5p.Conclusions:1.The expression of lncRNA H19 was increased in placental tissues of PIH,mPE and sPE.2.The expression of miR-let7b-5p and miR-let7e-5p were decreased in the placental tissues of PIH,mPE and sPE.The level of miR-let7b-5p in early-onset sPE was lower than that in late-onset sPE.The expression of miR-let7e-5p and lncRNA H19 was negatively correlated.3.The expression of MMP9 mRNA was decreased in PIH and sPE placenta tissues.However,there was no significant difference in the expression of MMP9 mRNA between mPE and the normal group.The level of MMP9 mRNA in early-onset sPE was lower than that in late-onset sPE.4.The expression of MMP9 protein was decreased in PIH,mPE and sPE placenta tissues.5.LncRNA H19 may be involved in the pathogenesis of HDP by depress the expression of miR-let7e-5p while promote MMP9 to regulate the invasion,migration,cell vitality of trophoblast cells.