The Association Between Nelin Gene And Coronary Heart Disease

Objective:To investigate the association between variants of Nelin gene and susceptibility and risk factors of coronary heart disease (CHD), and the effects of mRNA and protein expression of Nelin in hypobaric hypoxia induced rat cardiomyocytes.Methods:(1) The nucleotide sequences in the exon and exon-intron junction region of the Nelin gene in 101 CHD patients and 114 health individuals were determined by DNA sequencing technology, and were compared with the Genbank sequences determined by nucleotide sequence analysis software. (2) The height, weight and blood pressure of the subjects were detected, the serum level of Nelin was determined by enzyme-linked immunosorbent assay(ELISA), and the levels of TC, HDL-C, LDL-C, TG, Hs-CRP, Glu and Cre were detected with automatic biochemical analyzer. The relationship was analysed between the mutation of Nelin gene and risk factors of coronary heart disease as above. (3) The rat cardiomyocytes were cultured in vitro, and were simulated by hypobaric hypoxia, the expression of Nelin in hypobaric hypoxia induced cardiomyocyte was determined by RT-PCR and Western-blot.Results:(1) 2 SNPs was found among the exons, in which one was reported in the NCBI database(rs1166698) and one was new. The SNP(rs1166698)is a missense mutation(48364365 G/A)in the exon 8, the genotypes were 31.6%(G/G),52.6% (G/A), 15.8%(A/A)respectively, and the allele frequeney were 57.9%(G)and 42.1% (A) in control group, and the genotypes were 33.7%(G/G),49.5% (G/A),16.8%(A/A) respectively, and the allele frequeney were 58.45%(G)and 41.55% (A) in CHD group. The frequency of AA genotype and the frequency of A allele in CHD group was lower than that in control group, but both of them have no significant. (2) The serum level of Nelin was 0.88±0.74 ng/ml in patients of coronary heart disease, and 0.31±0.18 ng/ml in normal control, the CHD group was significantly higher than that in normal control(P<0.001). Increased serum levels of Nelin accout for 60.4% in CHD group. The levels of Hs-CRP,Glu and LDL-C were significantly higher than that in control group(P<0.001), and the HDL-C was lower(P＜0.001). (3)Compared with the AA genotype and GG+GA genotypes, the serum levels of Nelin and HDL-C were higher, others were lower, but all of them had no significant. (4)The results which extracted the total protein in hypo baric hypoxia induced cardiomyocyte detected by RT-PCR and Western blot showed that the expressions of mRNA and protein were decreased gradually with the time increased.Conclusion:The serum levels of Nelin was significantly increased in CHD group, and there were 60.4% increased. Showed that the association between variants of Nelin gene and coronary heart disease (CHD). The association between coronary heart disease and the SNP(rs1166698) was found. The expression of Nelin was decreased in hypobaric hypoxia induced cardiomyocytes. Indicated that gene of Nelin may play an inportant role in occurrence and development of coronary heart disease.