Abstract: Abstract：Objective To investigate the relationship between apolipoprotein E (APOE) promoter region-427T/C gene polymorphism and the incidence of coronary heart disease (CHD) and its effect on the transcriptional activity of APOE.Methods A total of 627 patients admitted to the department of cardiology, Tianjin chest hospital from October 2016 toSeptember 2017 were selected and divided into CHD group (n=415) and non-CHD group (n=212). The total cholesterol (TC)，triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), lipoprotein a[Lp (a)], apolipoprotein AI (APOAI), apolipoprotein B (APOB) and uric acid (UA) levels were detected after admission. The serum concentration of APOE was determined by enzyme-linked immunosorbent assay (ELISA). Polymerase chain reactionrestriction enzyme fragment length polymorphism (PCR-RFLP) was used to detect gene polymorphism at the -427T/C site.Logistic regression analysis was used to evaluate risk factors of coronary heart disease. The dual luciferase report gene expression vector pGL2 was used to build carry APOE -427TT wild type recombinant plasmid (TT group) and APOE-427CC variation homozygous type recombinant plasmid (CC group). The TT group, CC group, pGL2-basic no-load plasmid (controlgroup) and pRL-CMV internal reference plasmid were co-transfected into 293T cells by cationic liposome method. The fluorescence intensity of luciferase reporter gene was detected in the three groups to reflect the transcriptional activity of APOE. Results (1) Compared with the non-CHD group, data of age, male ratio, smoking ratio, history of diabetes, TG,Lp(a), HCY and UA were significantly increased in the CHD group, while the levels of APOAI and HDL-C were significantly decreased (P＜0.01). The genotype distribution in the two groups was consistent with the Hardy-Weinberg genetic balance(χ2=1.698，P＞0.05), and the C allele frequency was increased in CHD group than that of non-CHD group (19.8% vs. 12.4%,χ2=8.959, P＜0.05). (2) The level of APOB of TC+CC patients was higher in the CHD group than that in the TT group (P＜0.05), and APOA / APOB was lower in the TT group (P＜0.05). There were no significant differences in lipid and apolipoprotein levels between the two genotypes in the non-CHD group (P＞0.05). Multivariate Logistic regression analysis showed that smoking (OR=2.065, 95%CI：1.369-3.115), diabetes (OR=3.355, 95%CI：1.935-5.815), higher level of UA (OR=1.008, 95%CI: 1.005-1.010), and carrying -427C allele (OR=1.876, 95% CI：1.185-2.969) were risk factors for CHD. (3)The results of in vitro experiments showed that the transcriptional activity of APOE was significantly lower in CC group than that in TT group (P＜0.05). Conclusion Carriers of APOE-427C gene are risk factors for the incidence of coronary heart disease, and this site affects the plasma lipoprotein concentration and the incidence of coronary heart disease by affecting the transcriptional activity and synthesis level of APOE.

Key words: coronary disease, apolipoproteins E, polymorphism, single nucleotide, transcription initiation site, APOE-427T/C