摘要
目的观察慢性氟中毒大鼠大脑皮质神经细胞线粒体融合分裂基因mRNA含量和活性氧（ROS）水平，探讨其在氟中毒线粒体损伤中的作用。方法选取SD大鼠120只，按体重随机分为3组：对照组、低氟组、高氟组j每组40只。在饮水中加入不同剂量的氟化钠，含氟量分别为〈0．5、10、50mg／L，饲养3、6个月。采用线粒体ROS荧光探针法检测大鼠大脑皮质神经细胞线粒体ROS水平，实时荧光定量PCR法检测线粒体融合基因Mfnl及分裂基因Fisl、Drpl转录水平。结果3个月时，与对照组[10．434-5．98、（3．4±0．6）×10。、（8．8±1_4）×10、（1．24-0．2）×10。]比较，低氟组大鼠大脑皮质神经细胞线粒体ROS水平（11．674-3．49）未见明显改变（P〉0．05），线粒体融合分裂基因Mfnl、Drpl、FislmRNA表达水平未见明显改变[（3．1±0．3）×104、（6．7±2．7）×10、（5．0±0．9）×10，P均〉0．05]；而高氟组大鼠大脑皮质神经细胞线粒体ROS水平（25．48±6．09）显著升高（P〈0．05），线粒体融合分裂基因Mfnl、Drpl、FislmRNA表达水平[（1｜0-4-0．2）×10“、（3．04-1．6）×100、（8．9±3．6）×10。]明显升高（P均〈0．05）。6个月时，与对照组[25．264-6．41、（3．0±0．8）×10。、（5．14-0．8）×10’、（2．8±0．7）×10。]比较，低、高氟组大鼠大脑皮质神经细胞线粒体ROS水平（63．024-8．15、65．60±7．40）明显升高，线粒体融合基因MfnlmRNA表达水平[（3．04-0．4）×10‘、（4．0±0．9）×10。]显著降低，分裂基因Fisl、DrplmRNA表达水平[（2．0±0．8）×106、（4．0±0．6）×100，（3．8-I-1．3）×100、（1．3-t-O．2）×10。]明显升高（P均〈0．05）。结论摄人过量的氟导致大鼠大脑皮质神经细胞ROS水平升高，线粒体融合基因转录降低、分裂基因转录升高，这种改变与染氟时间和剂量呈正相关。线粒体融合分裂基因转录水平改变可能与慢性氟中毒引起的线粒体氧化应激升高有关。
Objective To investigate the transcriptional changes of nitochondria fission and fusion gene loci and reactive oxygen species (ROS) level in cortical neurons of rats with chronic fluorosis,and to reveal their roles in mitochondria damage due to chronic fluorosis.Methods SD rats were fed with different doses of fluoride through drinking water[＜ 0.5(control),10,50 mg/L,respectively] for 3 and 6 months.The level of ROS and mRNA contents of mitochondria fission gene loci Drp1/Fis1 and fusion gene locus Mfn1 in the cortical neurons of rat brains were detected with ROS fluorescent probe and real-time PCR,respectively.Results As compared with control group [10.43 ± 5.98,(3.4 ± 0.6) × 103,(8.8 ± 1.4) × 10,(1.2 ± 0.2) × 102] at the experiment period of 3 months,the level of ROS and mRNA contents of mitochondria fusion gene locus Mfn1 and fission gene loci Drp1/Fis1 in the cortical neurons were obviously increased in the rats fed with 50 mg/L fluoride through drinking water[25.48 ± 6.09,(1.0 ± 0.2) × 1011,(3.0 ± 1.6) × 103,(8.9 ± 3.6) × 102,all P ＜ 0.05],whereas no significant changes were found in the rats fed with 10 mg/L fluoride[11.67 ± 3.49,(3.1 ± 0.3) × 104,(6.7 ± 2.7) × 10,(5.0 ± 0.9) × 10,all P ＞0.05].Furthermore,at 6 months of the experiment the increases in ROS level(63.02 ± 8.15,65.60 ± 7.40) and mRNA contents of mitochondria fission gene loci Drp1/Fis1 [(2.0 ± 0.8) × 106,(4.0 ± 0.6) × 105,(3.8 ± 1.3) × 103,(1.3 ± 0.2) × 103] and the decrease in mitochondrial fusion gene locus Mfn1[(3.0 ± 0.4) × 106、(4.0 ± 0.9) × 104]were observed in the cortical neurons of the rats fed with 10 mg/L and 50 mg/L fluoride as compared with the control group[25.26 ± 6.41,(3.0 ± 0.8) × 109,(5.1 ± 0.8) × 103,(2.8 ± 0.7) × 102,all P ＜ 0.05].Conclusions Excessive intake of fluorine leads to elevated ROS levels,and decreased transcription of mitochondrial fusion gene loci Mfn1,which is positively correlated with the time and dose-exposed to fluoride.The changes of mitochondrial fission and fusion gene loci in the cortical neurons may be related to high level of oxidative stress induced by chronic fluorosis.
出处
《中国地方病学杂志》
CAS
CSCD
北大核心
2012年第2期125-129,共5页
Chinese Jouranl of Endemiology
基金
国家自然科学基金，科技部国际合作项目，贵州省科技基金项目
