The Relationship Between The Oestrogen Receptor α Gene Polymorphisms And Th1/Th2 Cytokine Drift In Female Systemic Lupus Erythematosus

ObjectiveTo investigate the association of the PvuⅡand XbaⅠrestriction fragment length polymorphisms(RFLP) of ERa and the Th1 and Th2 cytokine expression in studying the pathogenesis of SLE.MethodsGenomic DNA was extracted from whole blood(EDTA treated) using the TIANamp blood DNA kit supplied by the limited company of Tiangen biochemistry.To genotype the PvuⅡand XbaⅠrestriction polymorphic sites in intron 1 of ERαgene, polymerase chain reaction(PCR) and specific oligonucleotide primers were used.After amplification,the PCR products were digested with 10 units PvuⅡor XbaⅠat 37℃for 7h and electrophoresed in 1%ethidium bromide-agarose gel.PvuⅡdigestion reveals genotypes denoted PP(1.3kb),Pp(1.3kb,850bp,450bp),and pp(850bp,450bp),while XbaⅠcleavage results in genotypes XX(1.3kb),Xx(1.3kb,910bp,390bp),and xx(910bp, 390bp).Total RNA from 5×106 peripheral blood mononuclear cells(PBMC) was extracted using TRIzol and reversely transcripted into cDNA.The cDNA as the template, PCR was carried out with primers for IL-10,IFN-γ,IL-4 and IL-2.Each cytokine amplified withβ-actin at the same time in order to detect the cytokine' s quantity by ratios of the cytokine andβ-actin.ResultsNo significant difference was found in the distribution of ERαgenotypes between SLE patients and the healthy controls.But the IL-10 and IL-4 mRNA expression of SLE patients in PpXx genotype was higher than that of controls(P＜0.01).And in SLE patients the mRNA expression of IL-10 in PpXx genotype was obviously higher than other genotypes such as PPXX,PPXx,Ppxx,ppxx(P＜0.01),while the mRNA expression of IL-4 in PpXx genotype was higher than PPXX,Ppxx,ppxx(P＜0.05).The IFN-γand IL-2 mRNA expression of SLE patients in Ppxx genotype was lower than that of the healthy controls(P＜0.01).And in SLE patients the mRNA expression of IFN-γin Ppxx genotype was obviously lower than the PpXx and ppxx genotypes(P＜0.05,P＜0.01),while the mRNA expression of IL-2 in Ppxx genotype was lower than the PPXX,PpXx and ppxx genotypes(P＜0.05).The mRNA expression of IL-10,IL-4,IFN-γand IL-2 has no significant difference in various genotypes among the healthy controls.Conclusion1.We have confirmed that the ERαgene distribution in SLE patients was approximated to the healthy controls.The Th2 cell was predominant in SLE patients.2.The various ERαgenotypes were relevant to the different cytokine's expression.So the ERαgene polymorphisms may influence the cytokine's expression by serving as a genetic background.