ICAM-1基因K469E、K56M多态性对中国裕固族、藏族和汉族人血浆ICAM-1水平的影响

Effects of ICAM-1 Gene K469E,K56M Polymorphisms on PlasmasICAM-1 Expression Levels in Chinese Yugur,Tibetan and Han Nationalities

本研究检测中国裕固族、藏族和汉族3个民族人群血液中细胞间黏附分子-1(ICAM-1)基因K469E(A/G,rs5498)和K56M(A/T,rs5491)的基因多态性及血浆中可溶性ICAM-1(sICAM-1)水平,分析其基因型和等位基因频率在不同民族人群中的分布,探讨ICAM-1基因2个多态性位点对血浆中sICAM-1水平的影响。采集327例裕固族、400例藏族及126例汉族人群EDTA抗凝静脉血,采用大量全血基因组DNA提取试剂盒提取DNA,以PCR-RFLP进行DNA多态性分析,琼脂糖凝胶电泳后在凝胶扫描成像系统下判断基因型,DNA测序确定基因序列,比较ICAM-1基因型和等位基因频率在不同群体中的分布,通过Hardy-Weinberg遗传平衡定律检验群体代表性。采用人ICAM-1 ELISA试剂盒检测各民族人群血浆中sICAM-1水平。结果表明,DNA测序与PCR-RFLP分析结果一致。本研究检测到裕固族、藏族及汉族3个民族ICAM-1基因K469E位点KK、KE、EE 3种基因型,但它们的分布差异没有统计学意义,而K、E等位基因频率分布的差异有统计学意义(P<0.05)。裕固族和藏族分别与汉族群体之间的基因型和等位基因频率分布差异都有统计学意义(P<0.05)。K56M位点在3个民族中只检测出KK、KM 2种基因型,尚未检测到MM基因型;2种基因型和K、M等位基因频率分布在裕固族与汉族群体之间差异有统计学意义(P<0.05)。3个民族人群ICAM-1基因型和等位基因频率无明显性别比例和年龄分布差异,分布符合Hardy-Weinberg遗传平衡定律(P>0.05)。ICAM-1 K469E位点含K等位基因个体的sICAM-1血浆水平〔(253±122),(185±97)μg/L)〕高于不含K等位基因的个体〔(145±110)μg/L,P<0.01〕。ICAM-1 K56M位点含KK基因型的个体的sICAM-1血浆水平〔(253±122)μg/L〕高于KM基因型的个体〔(168±103)μg/L,P<0.01〕。裕固族和藏族群体中sICAM-1血浆水平〔(224±800),(214±111)μg/L〕高于汉族群体〔(175±125)μg/L,P<0.05〕,两两比较显示,裕固族与汉族群体及藏族与汉族群体中sICAM-1血浆水平差异有统计学意义(P<0.05)。结论:裕固族、藏族和汉族人群的ICAM-1 K469E和K56M 2个氨基酸位点基因型和等位基因频率均以KK/KE型、KK型和K等位基因为主,且裕固族和藏族的高于汉族,性别年龄间无明显差异,本研究对象中的ICAM-1基因型和等位基因频率分布具有群体代表性。ICAM-1基因K469E和K56M多态性影响血液中sICAM-1的血浆水平。K469E基因的K等位基因可能是某些疾病遗传危险因素,而K56M基因的M等位基因可能是其遗传保护因素。

This study was purposed to investigate the intercellular cell adhesion molecule-1（ICAM-1） gene K469E（A/G）（rs5498）and K56M（A/T）（rs5491）single nucleotide polymorphisms（SNP） and soluble ICAM-1（sICAM-1） levels in plasma in three Chinese populations of Yugur,Tibetan and Han nationalities,to analyze comparatively the genotypes and allele frequencies distribution in different ethnic groups,and to explore the effects of ICAM-1 K469E and K56M polymorphism and sICAM-1 levels in plasma.EDTA-anticoagulant venous blood from Yugur（327 cases）,Tibetan（400 cases） and Han（126 cases） people was collected,the DNA was extracted by using whole blood genomic DNA extraction kit,DNA SNP were analyzed by PCR-RFLP,genotype was judged by gel scan imaging system after agarose gel electrophoresis,the gene sequence was determined and the distribution of ICAM-1 genotypes and allele frequencies were compared among different ethnic groups,besides,the group representativeness was tested via the Hardy-Weinberg genetic equilibrium.Finally,the human sICAM-1 plasma levels were detected by using human ICAM-1 ELISA kit.The results showed that DNA sequencing result was consistent with PCR-RFLP analysis.In Yugur,Tibetan and Han nationalities,the KK,KE and EE three genotypes at ICAM-1 K469E gene locus were detected,the genotype distribution was not statistically significantly different,while the K,E allele frequency distribution was statistically significantly different（P 0.05）.Both of genotype and allele frequency distribution between Yugur,Tibetan and Han nationalities were statistically significantly different（P 0.05）.In K56M site only KK,KM two genotypes were detected,but the MM genotype was not detected in the three ethnic groups;the difference of two genotypes and K,M allele frequencies between Yugur and Han population was statistically significantly different（P 0.05）.Among three ethnic groups,the sex ratio and age distribution of K469E,K56M genotypes and allele frequencies of ICAM-1 gene were not significantly different,and distribution was in accordance with Hardy-Weinberg genetic equilibrium（P 0.05）.The plasma sICAM-1 level at ICAM-1 K469E allele locus in K individuals 〔（253 ± 122）,（185 ± 97） μg / L〕was higher than that at non-K allele 〔（145 ± 110） μg / L,P 0.01〕;the plasma sICAM-1 level of ICAM-1 K56M sites with KK genotype 〔（253 ± 122） μg / L〕was higher than that of the KM genotypes 〔（168 ± 103） μg / L,P 0.01〕.In Yugur and Tibetan groups,the plasma sICAM-1 levels 〔（224 ± 80）,（214 ± 111） μg / L〕were higher than that in the Han group 〔（175 ± 125） μg / L,P 0.05〕.Pairwise comparison indicated that the plasma sICAM-1 levels between Yugur and Han group were statistically significantly different（P 0.01）,that was significantly different between Tibetan and Han group（P 0.05）.It is concluded that in Yugur,Tibetan and Han population,the genotypes and gene frequencies of two amino acid sites K469E and K56M in ICAM-1 were KK / KE-type,KKtype and K allele,moreover,the ratio of them in Yugur and Tibetan group was higher than that in Han,while there is not significant difference in sex ratio and age distribution,therefore,ICAM-1 genotype and allele frequency distribution in this study had ethnic representativeness.ICAM-1 gene K469E and K56M polymorphisms were likely to affect the plasma sICAM1 expression level.K469E gene K allele may be a genetic risk factor,while K56M gene M allele a may be genetic protective factor for some diseases.