The Role And Mechanism Of Lipid Metabolism Disorders Mediated By LXRα And SREBP-1c In The Pre-eclampsia

Objective:1. To evaluate the expression and the correlations of liver X receptor α (LXRα) andits target gene sterol regulatory element-binding protein-1c(SREBP-1c) in placentaand serum during the course of pre-eclampsia (PE) and their relationship in PE.2. To evaluate the correlations between the expression of placenta and serum LXRαand its target gene SREBP-1c and abnormal lipid metabolism,and then theircorrelations in lipid metabolic disorders in PE.Methods: normal unfertilized group30cases,normal pregnancy group30cases,PEgroup30cases(mild14cases and severe16cases)1. The concentration of TC,TG,VLDL-C,LDL-C,HDL-C and FFA in the serum ofevery groups were detected by biochemical method.2. The protein expression of LXRα,SREBP-1c and oxLDL were analysised byimmunohistochemistry (IHC)in the placenta.3. The mRNA level of LXRαand SREBP-1c were measured by reversetranscription-polymerase chain reaction(RT-PCR)in the placenta.4. The concentration of LXRα and SREBP-1c in the serum of every groups weredetected by enzyme-linked immuno sorbent assay(ELISA).Results:1. PE group compared with normal pregnancy group, TC,TG,VLDL-C,LDL-C and AIwere significantly higher and HDL-C was lower(P＜0.01or P＜0.05).2. IHC,RT-PCR and ELISA all show that the expressions of mRNA and(or) protein ofoxLDL, LXRα and SREBP-1c increased gradually with significantly different levelsamong normal pregnancy，MPE and SPE groups(P＜0.01or P＜0.05).3. correlation analysis①There were positive correlations between the expression of placental LXRα mRNAand protein and serous LXRαprotein(r=0.417,r=0.527),TC(r=0.393,r=0.497), TG(r=0.415,r=0.514),VLDL-C(r=0.414,r=0.525),LDL-C(r=0.372,r=0.486),AI(r=0.313,r=0.399).②There were positive correlations between the expression of placental SREBP-1cmRNA and protein and serous SREBP-1c protein(r=0.497,r=0.664),TC(r=0.397,r=0.407),TG(r=0.477,r=0.480),VLDL-C(r=0.517,r=0.428),LDL-C(r=0.529,r=0.491).③There were positive correlation between the concentration of serous LXRα andserous SREBP-1c protein(r=0.662),TC(r=0.514),TG(r=0.553),VLDL-C(r=0.509),LDL-C(r=0.523),AI(r=0.496),negative with HDL-C(r=－0.282).④There were positive correlations between the concentration of serous SREBP-1cand TC(r=0.618),TG(r=0.707),VLDL-C(r=0.629),LDL-C(r=0.541),AI(r=0.586),negative with HDL-C（r=－0.278）.⑤There were positive correlations between the expression of placental oxLDL andplacental LXRα(r=0.396),serous VLDL-C(r=0.387),serous LDL-C(r=0.407).Conclusion:1. TC,TG,VLDL-C,LDL-C and AI were significantly higher and HDL-C was lower inPE group,suggests there is lipid metabolic disorders in PE.2. The expression of LXRα and SREBP-1c elevated distinctively in serum andplacenta, which mediated lipid metabolism disorders in matrix and placenta, vascularendothelial cell injury,are related to the occurrence and development of PE.3. LXRα,SREBP-1c in serum can be used as targets to predict preeclampsia andjudge severity of patient’s conditionone to guide clinical work.