The Mechanism And Effect Of MiR-424and Target Genes, FGFR1and MEK1in Fetal Growth Restriction

Part I the Study on microRNA-424differential expression level inhuman placenta tiuuse with fetal growth restrictionObjective: To investigate the differential expression level of microRNA-424in humanplacenta tiuuse with fetal growth restriction.to exploring the relationship between miR-424and FGR,to provide new idea and aproach for the molecular meehanism and play afoundation for exploring related biomolecular markers of fetal growth restriction.Mthods: Total RNA from50mg placental tissue was extracted using TRIzol reagentfollowing the manufacturer’s instructions. Real-time PCR analysis was then performed toexamine the levels of miRNA-424using Taqman assay kits,the correlations betweenmiR-424and FGR were analyzed.Result:①The birth weight was significantly lower in FGR group than control group,while there was no difference in maternal age, prepregnant weight and gestation at delivery;②the levels of miRNA-424in placentae quantified by quantitative real time PCR weresignificantly increased in pregnant women with FGR compared to control(p=0.002)；③MiR-424yields an AUC of0.754with88.6%sensitivity and68.0%specificity for separating FGR from normal controls. This study indicates that miR-424may be of diagnostic importance in FGR.Coclusion:MiR-424is particularly abundant in placental trophoblasts and that abundanceis a critical determinant of the biological activity of miRNAs。To regulate importantcellular functions, including differentiation,proliferation, cell cycle, and angiogenesis. inhuman placenta tiuuse with fetal growth restriction，Over-expression level of miRNA-424might participate the pathogenesis of fetal growth restriction. Part II the Study on target gene mitogen-activated protein kinase1and fibroblast growth factor receptor1differential expression level inhuman placenta tiuuse with fetal growth restrictionObjective：To investigate the differential expression level of mitogen-activated proteinkinase1and fibroblast growth factor receptor1in human placenta tiuuse with fetal growthrestriction. to exploring the relationship between target gene mitogen-activated proteinkinase1and fibroblast growth factor receptor1and FGR，to provide new idea and aproachfor the molecular meehanism。Methods: To determine the levels of MEK1and. FGFR1, extracted RNA was reversetranscribed to cDNA and Superscript II using an ABI7500Real Time PCR system. ThemRNA levels of MEK1and FGFR1genes were normalized using GAPDH. Western blotwas used to examine the protein expression level of the target genes of miR-424.forwestern blotting, placental tissues from five pregnant women with FGR or healthypregnant women were detected, Protein was analyzed with GAPDH as a loading control.Result:①The mRNA levels of both MEK1and FGFR1in placentae from women withFGR were significantly reduced compared to control (p=0.036).②Protein expressions ofboth MEK1and FGFR1were significantly reduced in placentae from women with FGRcompared to control。③Semi-quantitative analysis of western blotting showed75%and60%reduction of the protein levels of MEK1and FGFR1respectively.Conclusion: FGFR1and MEK1have a complex genomic organization and has beenimplicated throughout development in many signaling pathways controlling cellularproliferation, differentiation, survival, and angiogenesis,placenta development and fetalgrowth.both mRNA and protein levels of MEK1and FGFR1were significantly reduced inthe placentae associated with FGR, decreased levels of mRNA and protein levels ofMEK1and FGFR1are associated with the pathogenesis of fetal growth restriction. Part III TO stady the relationship and clinical effect between miR-424and target genes FGFR1and MEK1in fetal growth restrictionObjective: TO stady the relationship between miR-424and target genes FGFR1andMEK1in fetal growth restriction，to exploring their The mechanism and effect of miR-424and target genes, FGFR1and MEK1in fetal growth restriction.Methods: The correlation between relative expressions of miR-424and FGFR1andMEK1in FGR group was analyzed by the Spearman rank correlation coefficient usingPrism software。The relationship between miR-424and FGFR1and MEK1were analysed.Results:①The potential relationship between the levels of miRNA-424and mRNA levelsof MEK1or FGFR1in women with FGR was analyzed. The increased level ofmiRNA-424was negatively correlated with the mRNA levels of MEK1in women withFGR(Spearman r=-0.667; p=0.001)②The increased level of miRNA-424wasnegatively correlated tendency with the mRNA levels of FGFR1in women withFGR(Spearman r=-0.250; p=0.080)③The level of FGFR1was positive correlated withthe mRNA levels of MEK1in women with FGR(Spearman r=0.34, P <0.0001).Conclusion: Our results indicate that aberrant high expression level of miR-424mightplay important roles in the pathogenesis of FGR by suppressing MEK1and FGFR1. thereduced level of FGFR1and MEK1mRNA has a synergistic action. We propose thatmiR-424may participate in a miR-424-FGFR1-MEK1-MAPK network related to FGRdevelopment. These findings may provide new targets via miR-424in diagnosis andtherapy of FGR in the future.