硒代蛋氨酸通过PINK1/Parkin介导的线粒体自噬缓解氟诱导的抑郁样行为

Selenomethionine,through PINK1/Parkin-mediated Mitochondrial Autophagy,Alleviates Fluoride-induced Depressive-like Behavior

本文旨在探究PINK1/Parkin介导的线粒体自噬在硒代蛋氨酸(selenomethionine,Se-Met)缓解氟致抑郁样行为中的作用。选取40只BALB/c小鼠随机分为5组:空白对照组(C组)、氟组(NaF 150 mg·L^(-1),F组)、氟+低硒组(NaF 150 mg·L^(-1)+1.5 mg·L^(-1),F+LSe组)、氟+中硒组(NaF 150 mg·L^(-1)+3.0 mg·L^(-1),F+MSe组)、氟+高硒组(NaF 150 mg·L^(-1)+6.0 mg·L^(-1),F+HSe组)。氟化钠暴露90 d后,通过高架O型迷宫和悬尾试验观察小鼠的行为学表现,运用HE染色观察小鼠大脑皮质的损伤情况,采用生化试剂盒检测氧化应激相关指标的含量,并使用实时荧光定量PCR方法检测线粒体自噬相关基因的表达水平。动物行为学结果显示:与C组相比,F组小鼠在悬尾试验中的“静止”时间显著增加(P<0.05),在高架O型迷宫中进入闭合臂的时间有明显升高趋势(P<0.05)。在补充Se-Met后小鼠“静止”时间显著减少(P<0.05),F+LSe和F+MSe小鼠进入闭合臂的时间相比于F组显著减少(P<0.05)。病理组织切片结果显示:F组小鼠大脑皮质细胞排列紊乱,细胞体积缩小,且椎体细胞数量减少。经Se-Met改善后,F+LSe组的大脑皮质组织核仁清晰,细胞质更加均匀,改善效果更显著。氧化应激相关指标结果显示:与C组相比,F组活性氧(reactive oxygen species,ROS)显著升高(P<0.05),谷胱甘肽过氧化物酶(glutathione peroxidase,GSH-PX)含量显著减少(P<0.05)。与F组相比,F+LSe、F+HSe和F+MSe组ROS含量均显著降低(P<0.05),且含量依次表现为F+LSe-1 Se-Met可通过影响线粒体自噬相关基因的表达,恢复线粒体融合与分裂的动态平衡状态,缓解大脑皮质氧化应激,从而改善大脑皮质组织损伤和抑郁样行为的出现。

This experiment aims to investigate the role of PINK1/Parkin-mediated mitochondrial autophagy in the alleviation of fluoride-induced depressive-like behavior by selenomethionine(Se-Met).Forty BALB/c mice were selected and randomly divided into five groups:the blank control group(Group C),the fluorine group(NaF 150 mg·L^(-1),Group F),the fluorine+low selenium group(NaF 150 mg·L^(-1)+1.5 mg·L^(-1),Group F+LSe),the fluorine+medium selenium group(NaF 150 mg·L^(-1)+3.0 mg·L^(-1),Group F+MSe),the fluorine+high selenium group(NaF 150 mg·L^(-1)+6.0 mg·L^(-1),Group F+HSe).After 90 d of sodium fluoride exposure,the behavioral performance of mice was assessed by means of an elevated O-maze and hanging tail experiments;HE staining was used to evaluate the damage of the mouse cortex;biochemical kits were used to measure the content of oxidative stress-related indices;and real-time fluorescence quantitative PCR was utilized to determine the expression levels of mitochondrial autophagy-related genes.Animal behavioral results showed:the results indicated that mice in group F had a significantly longer"resting"time in the tail suspension test compared to group C(P<0.05)and a tendency to take more time to enter the closed arm of the elevated O-maze(P<0.05).After Se-Met supplementation,the"resting"time of mice was reduced significantly(P<0.05),and the F+LSe and F+MSe mice took significantly less time to enter the closed arm(P<0.05),compared to the F group.The results of the histopathological sections showed:the mice in group F had disorganized cortical cells,reduced cell volume,and fewer vertebral cells.Following Se-Met enhancement,the F+LSe group showed distinct nuclei and more uniform cytoplasm,and the improvement was notably more pronounced.The results of oxidative stress related indicators showed:group F had a significantly higher level of reactive oxygen species(ROS)(P<0.05),and a significantly reduced content of glutathione peroxidase(GSH-PX)(P<0.05),when compared to group C.Groups F+LSe,F+HSe,and F+MSe showed significantly lower levels of ROS(P<0.05).Compared to group F,the ROS content was considerably lower(P<0.05),in groups F+LSe,F+HSe,and F+MSe,with the content decreasing in the order of F+LSe<F+HSe<F+MSe;the GSH-PX content,on the other hand,was significantly higher(P<0.05),in groups F+LSe and F+HSe,compared to group F.Results of mRNA expression levels of autophagy-related genes were shown:group F showed significantly higher mRNA expression levels of autophagy-related genes Parkin,PINK1,LC3,OPTN,NBR1,Drp 1,and Fis1(P<0.05),compared to group C,and significantly lower mRNA expression levels of OPA1,Mfn 1,and Mfn2(P<0.05).Compared to group F,the mRNA expression levels of Parkin,PINK1,P62,NBR1,OPTN,and Fis 1 were significantly lower in the F+LSe and F+HSe groups(P<0.05),LC 3,Parkin,P 62 and Drp 1 were significantly decreased in the F+LSe and F+MSe groups(P<0.05),OPA 1 was significantly increased(P<0.05),and the F+LSe group showed a significant increase in the mRNA expression level of Mfn2(P<0.05).In summary,1.5 mg·L^(-1) of Se-Met can alleviate cortical oxidative stress by affecting the expression of mitochondrial autophagy-related genes,restoring the dynamic equilibrium state of mitochondrial fusion and fission,and thus ameliorating cerebral cortex damage and the emergence of depressive-like behaviors.