Ngwa Hilary Afeseh, Kanthasamy Arthi, Jin Huajun, Anantharam Vellareddy, Kanthasamy Anumantha G
Parkinson's Disorder Research Laboratory, Iowa Center for Advanced Neurotoxicology, Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA 50011-1250, USA.
Parkinson's Disorder Research Laboratory, Iowa Center for Advanced Neurotoxicology, Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA 50011-1250, USA.
Neurotoxicology. 2014 Jul;43:73-81. doi: 10.1016/j.neuro.2013.12.004. Epub 2013 Dec 18.
Epidemiological evidence indicates chronic environmental exposure to transition metals may play a role in chronic neurodegenerative conditions such as Parkinson's disease (PD). Chronic inhalation exposure to welding fumes containing metal mixtures may be associated with development of PD. A significant amount of vanadium is present in welding fumes, as vanadium pentoxide (V2O5), and incorporation of vanadium in the production of high strength steel has become more common. Despite the increased vanadium use in recent years, the neurotoxicological effects of this metal are not well characterized. Recently, we demonstrated that V2O5 induces dopaminergic neurotoxicity via protein kinase C delta (PKCδ)-dependent oxidative signaling mechanisms in dopaminergic neuronal cells. Since anosmia (inability to perceive odors) and non-motor deficits are considered to be early symptoms of neurological diseases, in the present study, we examined the effect of V2O5 on the olfactory bulb in animal models. To mimic the inhalation exposure, we intranasally administered C57 black mice a low-dose of 182μg of V2O5 three times a week for one month, and behavioral, neurochemical and biochemical studies were performed. Our results revealed a significant decrease in olfactory bulb weights, tyrosine hydroxylase (TH) levels, levels of dopamine (DA) and its metabolite, 3,4-dihydroxyphenylacetic acid (DOPAC) and increases in astroglia of the glomerular layer of the olfactory bulb in the treatment groups relative to vehicle controls. Neurochemical changes were accompanied by impaired olfaction and locomotion. These findings suggest that nasal exposure to V2O5 adversely affects olfactory bulbs, resulting in neurobehavioral and neurochemical impairments. These results expand our understanding of vanadium neurotoxicity in environmentally-linked neurological conditions.
流行病学证据表明,长期环境暴露于过渡金属可能在慢性神经退行性疾病如帕金森病(PD)中起作用。长期吸入含有金属混合物的焊接烟雾可能与PD的发生有关。焊接烟雾中存在大量钒,以五氧化二钒(V2O5)的形式存在,并且钒在高强度钢生产中的掺入变得更加普遍。尽管近年来钒的使用增加,但这种金属的神经毒理学效应尚未得到充分表征。最近,我们证明V2O5通过多巴胺能神经元细胞中蛋白激酶Cδ(PKCδ)依赖性氧化信号机制诱导多巴胺能神经毒性。由于嗅觉丧失(无法感知气味)和非运动缺陷被认为是神经疾病的早期症状,在本研究中,我们研究了V2O5对动物模型嗅球的影响。为了模拟吸入暴露,我们每周三次给C57黑小鼠鼻内给予低剂量的182μg V2O5,持续一个月,并进行行为、神经化学和生化研究。我们的结果显示,与载体对照组相比,治疗组嗅球重量、酪氨酸羟化酶(TH)水平、多巴胺(DA)及其代谢物3,4-二羟基苯乙酸(DOPAC)水平显著降低,嗅球肾小球层星形胶质细胞增加。神经化学变化伴随着嗅觉和运动功能受损。这些发现表明,经鼻暴露于V2O5会对嗅球产生不利影响,导致神经行为和神经化学损伤。这些结果扩展了我们对环境相关神经疾病中钒神经毒性的理解。