Li Yunhui, Ye Huayue, Du Min, Zhang Yanfen, Ye Boping, Pu Yuepu, Wang Dayong
Key Laboratory of Developmental Genes and Human Disease, Ministry of Education, Nanjing 210009, China.
J Environ Sci (China). 2009;21(7):971-9. doi: 10.1016/s1001-0742(08)62370-0.
Apart from the liver disruption, embryotoxicity and genotoxicity, microcystin (MC)-LR also could cause neurotoxicity. Nematode Caenorhabditis elegans was explored as a model to study the neurotoxicity. In the present study, we provided evidence to indicate the neurotoxicity on chemotaxis to NaCl and diacetyl, and thermotaxis from MC-LR exposure to C. elegans. As a result, higher concentrations of MC-LR caused significantly severe defects of chemotaxis to NaCl and diacetyl, and thermotaxis. The neurotoxicity on chemotaxis to NaCl and diacetyl, and thermotaxis from MC-LR exposure might be largely mediated by the damage on the corresponding sensory neurons (ASE, AWA, and AFD) and interneuron AIY The expression levels of che-1 and odr-7 were significantly decreased (P < 0.01) in animals exposed to MC-LR at concentrations lower than 10 microg/L, whereas the expression levels of ttx-1 and ttx-3 could be significantly (P < 0.01) lowered in animals even exposed to 1 microg/L of MC-LR. Moreover, both the chemotaxis to NaCl and diacetyl and the thermotaxis were more significantly reduced in MC-LR exposed mutants of che-1(p674), odr-7(ky4), ttx-1(p767), and ttx-3(ks5) than those in exposed wild-type N2 animals at the same concentrations.
除了对肝脏的破坏、胚胎毒性和基因毒性外，微囊藻毒素（MC）-LR还可导致神经毒性。本研究以秀丽隐杆线虫为模型来研究其神经毒性。在本研究中，我们提供证据表明MC-LR暴露会对秀丽隐杆线虫对氯化钠和双乙酰的趋化性以及对温度的趋性产生神经毒性。结果显示，较高浓度的MC-LR会显著导致对氯化钠和双乙酰的趋化性以及对温度趋性的严重缺陷。MC-LR暴露对氯化钠和双乙酰趋化性以及对温度趋性的神经毒性可能主要是由对相应感觉神经元（ASE、AWA和AFD）和中间神经元AIY的损伤介导的。在暴露于浓度低于10微克/升的MC-LR的动物中，che-1和odr-7的表达水平显著降低（P<0.01），而即使在暴露于1微克/升MC-LR的动物中，ttx-1和ttx-3的表达水平也会显著降低（P<0.01）。此外，在相同浓度下，暴露于MC-LR的che-1（p674）、odr-7（ky4）、ttx-1（p767）和ttx-3（ks5）突变体对氯化钠和双乙酰的趋化性以及对温度的趋性比暴露的野生型N2动物降低得更显著。
