线粒体细胞色素氧化酶3基因mRNA表达与支气管哮喘母系遗传的关系

Relationship between mitochondrial cytochrome oxidase mRNA expression and maternal inheritance of asthma

目的探讨线粒体细胞色素氧化酶基因亚基Ⅲ（COX3）mRNA表达水平与支气管哮喘母系遗传的关系。方法入选2009年1至12月于昆明医学院第一附属医院重症呼吸科及儿科住院的220例支气管哮喘患者作为哮喘组；其近亲家属（其父母或子女）162名作为近亲组，同期行健康体检的健康人群260名为对照组。测定所有入选者肺功能及血清IgE水平，通过实时荧光定量-PCR技术，检测外周血线粒体COX3mRNA表达水平并进行对比分析。结果哮喘组、近亲组、对照组年龄、性别差异均无统计学意义（均P〉0．05）；3组第1秒用力呼气量（FEV，）／用力肺活量（FVC）分别为90．6±6．2、92．3±2．3、102．3±2．3，FEV，占预计值的百分比分别为（82．9±10．8）％、（94．8±5．4）％、（98．3±8．6）％，组间差异均无统计学意义（均P〉0．05）；3组血液中线粒体COX3mRNA的表达水平分别为0．357±0．217、0．637±0．473和0．975±0．260，组间差异均有统计学意义（F=21．45，P=0．012）；哮喘组、近亲组IgE水平均显著高于对照组[（283．6±62．4）、（116．4±57．5）比（52．3±13．7）μg/L，均P〈0．05]；3组血液中COX3mRNA表达与IgE水平均呈负相关（r=-0．73、-0．56、-0．61，P=0．013、0．035、0．028）。结论哮喘患者线粒体COX3基因mRNA表达下调，可能通过影响机体IgE水平，参与了哮喘过敏性炎症反应，与哮喘母系遗传有关。

Objective To explore the relationship between the mRNA expression level of mitochondrial cytochrome oxidase and the maternal inheritance of asthma. Methods From January to December 2009, 220 asthma patients, 162 patient kins and 260 healthy subjects were recruited from Departments of Respiratory Critical Care Medicine and Pediatric Medicine at First Affiliated Hospital, Kunming Medical College. Lung function tests were performed and serum IgE level measured. The polymorphism of mitochondrial cytochrome oxidase gene polymorphisms was detected by direct sequencing. And the peripheral level of COX mRNA was measured by reverse transcription-polymerase chain reaction （RT-PCR）. Results No significant difference existed in age, gender among 3 groups. For 3 groups, the first second forced expiratory volume （ FEV1 ）/forced vital capacity （FVC） were 90. 6 ± 6.2, 92. 3 ± 2. 3, 102. 3±2. 3 and FEV1 percentage of expected value （FEV1%） were （82. 9 ± 10. 8）%, （94. 8 ±5.4）% and （98.3 ± 8.6） % respectively. The lung function was not significant difference among three groups. The mRNA expression level of mitochondrial cytochrome oxidase in peripheral blood were 0. 357 ± 0. 217, 0. 637 ± 0. 473 and 0. 975 ± 0. 260 in the asthma, kin and control groups respectively. No significant difference existed in the expression level of COX3 mRNA among 3 groups （ F = 21.45, P = 0. 012）. The serum level of lgE was the highest for the asthma patients. And it was significantly higher in the asthma group than that in the control group （ （283.6 ±62.4） vs （52. 3 ± 13.7） p,g/L, F =48.31, P 〈0. 05）. Moreover, the serum level of IgE was significantly higher in the kin group than that in the control group （ （ 116.4 ± 57.5 ） vs（52. 3 ± 13.7 ）μg/L, F = 20.45, P 〈 0.05 ）. However, there was a negative correlation between the mRNA expression level of mitochondrial cytochrome oxidase and the serum level of IgE among 3 groups. Conclusions The down-regulated mRNA expressin of mitochondrial cytochrome oxidase may participate in allergic inflammation by regulating the level of IgE. And the maternal inheritance of asthma is in effect.