Magnetic resonance imaging investigations reveal that PM2.5 exposure triggers visual dysfunction in mice
Magnetic resonance imaging investigations reveal that PM2.5 exposure triggers visual dysfunction in mice
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磁共振成像研究表明 PM2.5 暴露会引发小鼠视觉功能障碍
DOI：
10.1016/j.ecoenv.2021.112866
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发表时间：
2021
影响因子：
6.8
通讯作者：
Tang Zuohua
中科院分区：
文献类型：
--
作者：
Guo Linying;Wang He;Zhou Ji;Tang Weijun;Wang Rong;Xiao Zebin;Wu Lingjie;Wang Jie;Li Liping;Lei Yuan;Sun Xinghuai;Tang Zuohua
目的探讨PM2. 5暴露对小鼠视觉系统微结构、代谢产物和功能的影响。方法将C57 BL/6 J小鼠随机分为过滤空气组（对照组）和高浓度PM2. 5组（PM2. 5组）。行视觉诱发电位（VEP）、视网膜电图（ERG）、弥散张量成像（DTI）、质子磁共振波谱（1H-MRS）和静息态功能MRI（rsfMRI）检查。比较两组患者VEP的P1波、N1波、P2波的波幅及波幅，ERG的a波、B波的波幅及波幅，DTI的各向异性分数（FA）、平均弥散（MD）、轴向弥散（AD）、径向弥散（RD），1H-MRS的视皮层（VC）代谢产物，结果与对照组比较，PM2.5组N1潜伏期延长（43.11 ± 7.94 ms vs. 38.75 ± 4.60 ms）和降低VEP上的P1振幅（5.62 ± 4.38 μ V vs. 8.56 ± 5.92 μ V）（所有p <0.05）。ERG上a波振幅降低（− 91.39 ± 56.29 μ V vs. − 138.68 ± 89.05 μ V），B波振幅降低（194.38 ± 126.27 μ V与284.72 ± 170.99 μ V），B波潜伏期（37.78 ± 10.72 ms）较对照组（33.01 ± 4.34 ms）延长（P均<0.05）。DTI显示PM2.5小鼠双侧梨状皮质（Pir）FA增加，双侧躯体感觉皮质（S）和双侧纹状体（Stri）FA减少，双侧VC、右侧S和双侧Pir AD减少，双侧Pir MD减少，双侧Pir RD减少1H-MRS显示PM2.5组VC中谷氨酸（Glu）和磷酸胆碱（PCh）含量较对照组增加（PCh 1.63 ± 0.25 vs.1.50 ± 0.25; PCh/tCr 0.19 ± 0.03 vs.0.18 ± 0.03; Glu 10.46 ± 1.50 vs.9.60 ± 1.19; Glu/tcr 1.23 ± 0.11 vs. 1.12 ± 0.11）（均p <0.05）。rsfMRI显示PM2.5小鼠左上丘、左侧运动皮层、海马、导水管周围灰质和右侧中脑网状结构中的ReHo较高（均p <0.01，AlphaSim校正）。
ObjectivesTo investigate how PM2.5exposure affects the microstructure, metabolites or functions of the visual system.MethodsC57BL/6J mice were randomly assigned to groups exposed to the filtered air (the control group) or the concentrated ambient PM2.5(the PM2.5group). Visual evoked potentials (VEP), electroretinograms (ERG), diffusion tensor imaging (DTI), proton magnetic resonance spectroscopy (1H-MRS) and resting-state functional MRI (rsfMRI) were performed. Parameters were obtained and compared between the two groups, including latencies and amplitudes of the P1 wave, N1 wave and P2 wave from VEP, latencies and amplitudes of the a wave and b wave from ERG, fractional anisotropy (FA), mean diffusion (MD), axial diffusivity (AD) and radial diffusivity (RD) from DTI, visual cortex (VC) metabolites from1H-MRS, and regional homogeneity (ReHo) from rsfMRI.ResultsCompared with the values of the control group, the PM2.5group showed a prolonged N1 latency (43.11 ± 7.94 ms vs. 38.75 ± 4.60 ms) and lowered P1 amplitude (5.62 ± 4.38 μV vs. 8.56 ± 5.92 μV) on VEP (all p < 0.05). On ERG, the amplitude of the a wave was lowered (− 91.39 ± 56.29 μV vs. − 138.68 ± 89.05 μV), the amplitude of the b wave was lowered (194.38 ± 126.27 μV vs. 284.72 ± 170.99 μV), and the latency of the b wave was prolonged (37.78 ± 10.72 ms vs. 33.01 ± 4.34 ms) than the values of the control group (all p < 0.05). DTI indicated FA increase in the bilateral piriform cortex (Pir), FA decrease in the bilateral somatosensory cortex (S) and the bilateral striatum (Stri), AD decrease in the bilateral VC, the right S and the bilateral Pir, MD decrease in the bilateral Pir, and RD decrease in the bilateral Pir in the PM2.5mice (all p < 0.05, Alphasim corrected).1H-MRS showed Glutamate (Glu) increase and Phosphocholine (PCh) increase in the VC of the PM2.5group than those of the control group (PCh 1.63 ± 0.25 vs. 1.50 ± 0.25; PCh/total creatine(tCr) 0.19 ± 0.03 vs. 0.18 ± 0.03; Glu 10.46 ± 1.50 vs. 9.60 ± 1.19; Glu/tcr 1.23 ± 0.11 vs. 1.12 ± 0.11) (all p < 0.05). rsfMRI showed higher ReHo in the PM2.5mice in the left superior colliculus, the left motor cortex, the hippocampus, the periaqueductal gray and the right mesencephalic reticular formation (all p < 0.01, AlphaSim corrected).ConclusionsThis study revealed that PM2.5exposure triggered visual dysfunction, and altered microstructure, metabolite and function in the retina and visual brain areas along the visual system.