Impact of citreoviridin on mRNA expression of mitochondrial respiratory chain synthesis related transcriptional regulation gene, membrane potential and reactive oxygen species in rat cardiomyocytes / 中国地方病学杂志

ABSTRACT

Objective To investigate the impact of citreoviridin(CIT) on mRNA expression of mitochondrial respiratory chain synthesis related transcriptional regulation gene,mitochondrial membrane(MMP) potential and reactive oxygen species (ROS) in cardiomyocytes of rat.Methods Viability of rat primary cardiomyocytes treated with different concentrations of CIT (0,1,2,3,4,5,6,7,8,9,10 μmol/L) for 24 h was determined by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method.Based on the MTT curve,median inhibitory concentration(IC50) was calculated using SPSS 13.0.High-,medium-and low-dose groups of CIT(1.650,1.234,0.715 μmol/L) were defined corresponding to 99％,95％ and 90％ of cardiomyocyte viability,respectively.CIT was not added in as the control group.After 24 hours,the mRNA expression levels of peroxisome-proliferator-activated receptor γcoactivator(PGC-1α),nuclear respiratory factor 1 (Nrf1) and nuclear respiratory factor 2(Nrf2) in cardiomyocytes were detected by reverse transcriptase polymerase chain reaction(RT-PCR).Changes of MMP and intracellular ROS were determined by a fluorescence microplate reader using 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolcarbocyanine iodide (JC-1) and 2,7-dichlorofluorescein diacetate (DCFH2-DA) as fluorescent probes.Results Compared with 0 μmol/L CIT group [(89.4 ± 17.6)％],viabilities of rat primary cardiomyocytes treated with 2-10 μmol/L CIT groups[(80.2 ± 20.2)％,(74.4 ± 18.7)％,(63.2 ± 8.9)％,(51.5 ± 18.8)％,(39.0 ± 15.7)％,(22.6 ± 10.5)％,(19.9 ± 4.9)％,(20.7 ± 4.8)％,(18.5 ± 3.3)％] decreased significantly(all P ＜ 0.05).The IC50 value of cardiomyocytes after24 h treatment with CIT was 4.6 μmol/L The PGC-1α mRNA expressions ofhigh-,medium-and low-dose groups(0.431 ± 0.041,0.619 ± 0.031,0.653 ± 0.037) were significantly lower compared to that of the control group(0.776 ± 0.081,all P ＜ 0.05).The Nrf1 mRNA expression of high-dose group(0.358 ± 0.05) was significantly lower compared to that of the control group(0.580 ± 0.098,P ＜ 0.05).Nrf2 mRNA expressions of the high-and medium-dose groups(0.352 ± 0.041,0.472 ± 0.011) were significantly lower than that of the control group (0.667 ± 0.091,all P＜ 0.05).Compared with the control groups[(100.00 ± 0.00)％,(100.00 ± 0.00)％],the MMP levels of high-,medium-and low-dose groups[(55.3 ± 3.3)％,(69.8 ± 4.7)％,(81.8 ± 2.7)％] were significantly lower and the ROS levels[(606.0 ± 46.3)％,(275.0 ± 53.5)％,(158.9 ±29.5)％] were significantly higher(all P ＜ 0.05).Conclusions CIT inhibits the biosynthesis of mitochondria in primary cardiomyocytes and induces oxidative stress.Myocardial injury is caused by cardiomyocyte apoptosis through mitochondrial pathway,which leads to myocardial injury.