高铜诱导肉鸡心肌氧化损伤和内质网应激

探讨高铜对肉鸡心肌氧化损伤和内质网应激的影响,将48羽1日龄白羽肉鸡随机平均分为4组,分别饲喂对照日粮(Cu 11 mg/kg,对照组)和高铜日粮(Cu 110 mg/kg,高铜I组;Cu 220 mg/kg,高铜Ⅱ组;Cu 330 mg/kg,高铜Ⅲ组)。49日龄时进行心脏采集,制备切片观察心脏组织病理学变化,检测心肌总抗氧化能力(T-AOC)、超氧化物歧化酶(SOD)活性、过氧化氢酶(CAT)活性、谷胱甘肽还原酶(GR)活性及丙二醛(MDA)含量的变化,实时荧光定量PCR检测内质网应激相关基因GRP78、GRP94、eIF2α、ATF6、XBP1、CHOP的mRNA转录水平,Western blot检测GRP78蛋白表达水平。结果显示,与对照组相比,高铜组心肌纤维间隙增宽;随着日粮中铜含量的增加,心脏组织中T-AOC、SOD、CAT和GR活力下降,MDA含量显著升高(P<0.05),GRP78、GRP94、eIF2α、ATF6、XBP1和CHOP mRNA表达量升高,GRP78蛋白表达显著上调(P<0.05)。结果表明,高铜可以诱导心肌氧化损伤和内质网应激。

High level of copper induces oxidative damage and endoplasmic reticulum stress in myocardium of broilers

To investigate whether high level of copper can induce oxidative damage and endoplasmic reticulum stress in heart of broilers,48 one-day-old healthy white feather broilers were randomly divided into 4 groups with 12 birds in each-group in this study.The broilers were fed with diets as follows:control diet(Cu 11 mg/kg,control group),and high-Cu diets(Cu 110 mg/kg,high-Cu group I;Cu 220 mg/kg,high-Cu group Ⅱ;Cu 330 mg/kg,high-Cu group Ⅲ).The heart tissues were collected on day 49 for pathologic examination.The activities of total antioxidant capacity(T-AOC),superoxide dismutase(SOD),catalase(CAT),glutathione reductase(GR) and the content of malondialdehyde(MDA) were detected.Moreover,the mRNA expression levels of GRP78,GRP94,eIF2α,ATF6,XBP1 and CHOP were measured by real-time quantitative PCR(RT-qPCR),and the protein expression of GRP78 was determined by Western blot.The results showed that the myocardial fiber gap in the high-Cu group was widened compared to control group.With the increase of dietary Cu,the activities of T-AOC,SOD,CAT,GR were significantly decreased and the content of MDA was markedly increased(P<0.05).Furthermore,the mRNA expression levels of GRP78,GRP94,eIF2α,ATF6,XBP1 and CHOP were increased in high-Cu group compared to control group,and the protein expression level of GRP78 was also up-regulated remarkedly(P<0.05).These results suggested that high level of Cu could induce oxidative damage and endoplasmic reticulum stress in myocardium of broilers.