摘要
目的观察硒、蛋白质和维生素E（VE）对大鼠心肌硒蛋白mRNA表达的影响，探讨其与心肌损伤的关系。方法将40只雄性Wistar大鼠分为4组：低硒低蛋白低VE组，低硒低蛋白常VE组，常硒常蛋白低VE组，常硒常蛋白常VE组，每组10只。6个月时，采用二硫双硝基苯甲酸（DTNB）法检测全血谷胱甘肽过氧化物酶（GSH—Px）活力；用实时荧光定量（Real—time，RT）PCR法检测心肌细胞内谷胱甘肽过氧化物酶1（Gpxl）、磷脂氢谷胱甘肽过氧化物酶4（Gpx4）、硫氧还蛋白还原酶（TrxR）、硒蛋白P（Se—P）和硒蛋白W（Se—W）mRNA表达；光镜下观察心肌组织病理学变化。结果6个月时，低硒低蛋白低VE组、低硒低蛋白常VE组、常硒常蛋白低VE组、常硒常蛋白常VE组全血GSH—Px活力分别为（44．6±3．1）、（45．5±1．6）、（86．6±2．2）、（85．6±1．2）U／L，组间比较差异有统计学意义（F=100．7，P〈0．01）。其中常硒常蛋白低VE组、常硒常蛋白常VE组的全血GSH—Px活力高于低硒低蛋白低VE组、低硒低蛋白常VE组（P均〈0．05）。上述4组大鼠心肌组织Gpxl（0．099±0．312、0．054±0．007、0．386±0．067、0．340±0．085）、Gpx4（1．005±0．089、0．810±0．229、0．895±0．084、0．922±0．399）、Se—W（0．188±0．080、0．119±0．069、0．574±0．167、0．570±0．383）mRNA表达组间比较，差异有统计学意义（F值分别为112．1、3．76、22．8，P均〈0．05）。其中常硒常蛋白低VE组、常硒常蛋白常VE组Gpx1、se—wmRNA表达高于低硒低蛋白低VE组、低硒低蛋白常VE组（P均〈0．05），低硒低蛋白低VE组Gpx4mRNA表达高于常硒常蛋白低VE组（P〈0．05）。而上述4组大鼠心肌组织TrxR、Se—PmRNA表达水平（0．130±0．037、0．127±0．038、0．134±0．021、0．120±0．014，0．446±0．155、0．413±0．152、0．385±0．041、0．408±0．208）组间比较，差异无统计学意义（F值分别为0．91、1．75，P均〉0．05）。光镜下上述4组大鼠心肌组织病理学改变主要表现为灶状凝固性坏死，坏死检出率分别为80％（8／10）、44％（4／9）、20％（2／10）、10％（1／10），组间比较差异有统计学意义（Fisher精确检验，P=0．0067）。结论长期低硒、低蛋白质和低VE摄入使机体抗氧化能力降低，导致心肌损伤的发生；Gpx1、Se—WmRNA表达与硒水平密切相关，Gpx4、TrxR、Se—PmRNA表达则未见明显相关性。
Objective To explore the effect of selenium, protein and vitamin E deficiency on mRNA expression of rat cardiac selenoprotein, and their relation with myocardial injury. Methods Forty male Wistar rats were randomly divided into 4 groups： low selenium low protein low vitamin E group （group A）, low selenium low protein adequate vitamin E group （group B）, adequate selenium adequate protein low vitamin E group （group C）, and adequate selenium adequate protein adequate vitamin E group （group D）, 10 rats in each group. The activity of whole blood glutathione peroxidase（GSH-Px） was measured using dithiobis nitrobenzoic acid（DTNB） at the end of sixth month experiment. The levels of mRNA expression of glutathione peroxidase 1 （Gpx 1）, phospholipid hydroperoxide glutathione peroxidase 4（Gpx4）, thioredoxin reductase（TrxR）, selenoprotein P（Se-P） and selenoprotein W（Se-W） were determined by real-time fluorescence quantitative PCR at the end of sixth month. Histopathological changes of myocardial injury were observed with light microscope. Results The activity of GSH-Px was （44.6 ± 3.1）, （45.5 ± 1.6）, （86.6 ± 2.2）, （85.6 ± 1.2）U/L, respectively, in the above four groups at the end of sixth month, and the difference was statistically significant（F = 100.7, P 〈 0.01 ） ; the activity of GSH-Px of groups C and D was higher than that of groups A, B（all P 〈 0.05）. mRNA expression of myocardial tissue of the four groups was as follows, Gpxl （0.099 ± 0.312, 0.054 ± 0.007, 0.386 ± 0.067, 0.340 ± 0.085）, Gpx4（1.005 ± 0.089, 0.810 ± 0.229, 0.895 ± 0.084, 0.922 ± 0.399）, and Se-W（0.188 ± 0.080, 0.119 ± 0.069, 0.574 ± 0.167, 0.570 ± 0.383）, and the difference was statistically significant（F= 112.1, 3.76, 22.8, all P 〈 0.05）; the mRNA levels of Gpxl, Se-W of groups C, D were significantly higher than that of groups A, B （all P 〈 0.05 ）. The mRNA expression of Gpx4 of group A was higher than that of group C（P 〈 0.05）. The mRNA expression of TrxR（0.130 ± 0.037, 0.127 ± 0.038, 0.134 ± 0.021, 0.120 ± 0.014） and Se-P（0.446 ± 0.155, 0.413± 0.152, 0.385 ± 0.041, 0.408 ± 0.208 ） was not statistically different among the four groups（F = 0.91, 1.75, all P 〉 0.05）. Pathological changes of myocardial tissue were mainly as foci of eoagulative necrosis. The necrosis detection rate of the four groups was 8/10, 4/9, 2/10, and 1/10, respectively, and the difference was significant statistically（Fisher exact test, P= 0.0067）. Conclusions Long-term selenium, protein and vitamin E deficiency will reduce body antioxidant capacity and lead to myocardial injury. The mRNA levels of Gpxl and Se-W and selenium level are closely related. The mRNA levels of Gpx4, TrxR and Se-P remain relatively stable.
出处
《中国地方病学杂志》
CAS
CSCD
北大核心
2012年第3期279-282,共4页
Chinese Jouranl of Endemiology
基金
基金项目：国家自然科学基金（30471497）
黑龙江省自然科学基金重点项目（ZJY04-07）
黑龙江省教育厅科学技术研究项目（11511149）
