线粒体靶向抗氧化剂对尼古丁诱发大鼠心脏改变的影响

Effects of Mitochondria-targeted Antioxidants on Nicotine-induced Cardiac Changes in Rats

目的观察白藜芦醇和mitoTEMPO对尼古丁诱导的心脏重塑、氧化和炎症的影响,为开展线粒体途径预防和治疗心脏疾病提供研究数据。方法SD大鼠每天给予0.6 mg/kg尼古丁,同时分别给予mitoTEMPO或白藜芦醇或对照剂,连续28 d。收集各组大鼠心脏组织,分析心脏结构及参数变化,检测线粒体ROS、谷胱甘肽(GSH)和SOD2活性水平,免疫组化法检测氧化应激标志物3-硝基酪氨酸表达情况,最后采用分子生物学方法检测抗氧化基因、促肥厚基因、纤维化基因和炎症相关基因的表达情况。结果尼古丁导致大鼠心脏重量增加。心肌线粒体ROS和3-硝基酪氨酸表达升高,SOD的酶活性显著降低(P<0.05),大鼠心脏氧化应激水平增加。基因表达分析显示,尼古丁使NOX2、ANP和BNP的表达上调(P<0.05)。促炎因子TNF-α和IL-6基因表达显著升高(P<0.05)。mitoTEMPO和白藜芦醇给药能够显著降低尼古丁诱导的心脏重量。同时降低了尼古丁诱导的线粒体ROS生成,降低3-硝基酪氨酸和NOX2的表达水平(P<0.05)。白藜芦醇可使大鼠心脏SOD活性显著提高(P<0.05)。同时降低尼古丁诱导的心肌细胞肥大以及ANP和BNP的基因表达(P<0.05)。白藜芦醇还降低了尼古丁诱导的TGFβ1、TNF-α、IL-6表达上调(P<0.05)。mitoTEMPO可使大鼠ANP的基因表达明显下降(P<0.05)。结论线粒体靶向抗氧化剂mitoTEMPO或白藜芦醇能够影响线粒体活性氧生成并可部分减弱尼古丁诱导的心肌改变。

Objective To observe the effects of resveratrol and mitoTEMPO on nicotine-induced cardiac remodeling,oxidation and inflammation,and to provide research data for mitochondrial pathway prevention and treatment of heart diseases.Methods SD rats were given 0.6 mg/kg nicotine daily and mitoTEMPO,resveratrol or control agent,respectively,for 28 days.Cardiac tissues were collected from each group,the changes of cardiac structure and parameters were analyzed,and the activity levels of mitochondrial ROS,glutathione(GSH)and SOD2 were detected.The expression of oxidative stress marker 3-nitrotyrosine was detected by immunohistochemistry.Finally,the expressions of antioxidant genes,hypertrophic genes,fibrosis genes and inflammatory genes were detected by molecular biological methods.Results Nicotine caused heart weight to increase in rats.The expressions of ROS and 3-nitrotyrosine in myocardial mitochondria were increased,the activity of SOD was significantly decreased(P<0.05),and the level of oxidative stress in the heart of rats was increased.Gene expression analysis showed that nicotine up-regulated the expressions of NOX2,ANP and BNP(P<0.05).The expressions of pro-inflammatory cytokines TNFαand IL-6 were significantly increased(P<0.05).MitoTEMPO and resveratrol administration significantly reduced nicotine-induced heart weight.Meanwhile,nicotine-induced mitochondrial ROS production and expression levels of 3-nitrotyrosine and NOX2 were decreased(P<0.05).Resveratrol could significantly increase SOD activity in rat heart(P<0.05).Meanwhile,nicotine-induced cardiomyocyte hypertrophy and gene expressions of ANP and BNP were decreased(P<0.05).Resveratrol also decreased nicotine-induced up-regulation of TGFβ1,TNF-αand IL-6 expression(P<0.05).mitoTEMPO could significantly decrease the gene expression of ANP in rats(P<0.05).Conclusion Mitochondria-targeted antioxidants mitoTEMPO or resveratrol affect mitochondrial reactive oxygen production and partially attenuates nicotine-induced myocardial changes.