The Neurotoxicity Effects Of Fenpropathrin On The Nigrostriatal Dopaminergical Pathways

Section1The Effect of Fenpropathrin on cell ability, apoptosis and oxidative stress in SH-SY5Y cell lineObjective To investigate the effect of fenpropathrin on cell viability, apoptosis and oxidative stress.Methods SH-SY5Y cells were treated with fenpropathrin for different doses and different periods. The cell viability was detected by MTT assay. The cell apoptosis rates were measured using flow cytometry by FITC-Annexin V/PI staining. The mitochondrial membrane potential (MMP) changes were detected using flow cytometry by JC-1staining. DCFH-DA staining was used to detect the level of ROS. The protein levels of caspase-3and bcl-2was measured using western blotting.Results MTT assay indicated that fenpropathrin decreased the SH-SY5Y cell viability in a dose and time dependent manner. Flow cytometry analysis indicated that fenpropathrin induced SH-SY5Y cell apoptosis in a dose-and time-denpendent manner, decreased MMP in a time-dependent manner and increased oxidative stress to SH-SY5Y cells in time dependent manner. While western blotting data showed that caspase-3actived and bcl-2protein was decreased in a dose-dependent manner.Conclusion Fenpropathrin might decrease the cell viability of SH-SY5Y cells and induce apoptosis and oxidative stress, which were pathogenesis of Parkinson’s disease. Objiective To indentify the effects of fenpropathrin on α-synuclein, ubiquitin and P62aggregation Methods SH-SY5Y cells were treated with fenpropathrin. HE staining was used observe the cytosolic inclusion. Laser Scanning Confocal Microscope (LSCM) was used to observe the α-synuclein, ubiquitin and P62distribution and comformational change after fenpropathrin exposure. Western blot was used to detect the protein level of α-synuclein, ubiquitin and P62.Results There were eosinphilic inclusions in cytoplasm after fenpropathrin treatment. Alpha-synuclein, ubiquitin and P62distributed uniformly in the cytoplasm. After fenpropathrin treatment α-synuclein, ubiquitin and P62was much higher and α-synuclein, ubiquitin and P62positive aggregates were observed in cytoplasm.Inclusion Fenpropathrin could induce α-synuclein, ubiquitin and P62aggregation. Objective To explore the possible mechanism involved in fenpropathrin induced a-synuclein, ubiquitin and P62aggregationMethods SH-SY5Y cells were treated with fenpropathrin, combined with Rapamycin or3-MA pretreatment. MTT was used to detect the cell viability. Western blot was used to detect the protein level of LC3and P62. Laser Scanning Confocal Microscope (LSCM) was used to observe the LC3aggregates.Results Western blot showed that the ratio of LC3-II/LC-I was increased after fenpropathrin treatment, and then decreased in a time-dependent manner, the protein level of P62was increased in a time-dependent manner after fenpropathrin treatment. LCSM found that LC3become aggregated in the cytoplasm after fenpropathrin treatment. Rapamycin pretreatment could increase the cell viability and decreased the protein level of a-synuclein, ubiquitin and P62. While3-MA pretreatment had no effects on protein aggregates induced by fenpropathrin.Inclusion Autophagy lysosome pathway may be involved in protein aggregates induced by fenpropathrin. Enhanced autophagy may decrease the toxicity of fenpropahtin. Section1The Toxic Effect of Fenpropathrin on Dopaminergic System of MiceObjective To explore and compare the effects of fenpropathrin intraperitoneal injection or combined with DA stereotacical injection on dopamine system of mice.Method Fenpropathrin was injected intraperitoneally or combined with the DA stereotactically injected at the striatum of the mouse brain. The behaviors features of animals were investigated using pole jumping test and head up test. HLPC was used to detect the fenpropathrin in the mice brain after fenpropathrin intraperitoneal injection. The immunoreactivity of tyrosine hydroxylase, DAT and VMAT2in the brains were observed by immunohistochemistry.Results Behavior investigation indicated that both fenpropathrin intraperitoneal injection or combined with the DA stereotactically injection could decrease the mice’s activity. HLPC detect fenpropathrin in the brain. Immunohistochemistry study suggested that the tyrosine hydroxylase immunoreactivity were decreased in striatum of fenpropathrin combined with the DA group. DAT immunoreactivity were increased in the striatum after fenpropathrin exposure.Conclusion Fenpropathrin could cross the blood brain barrier, enhanced the toxicity of DA on dopamine system. Objective To explore and compare the toxic effects of Fenpropathrin on Dopaminergic system of rats Method Fenpropathrin was injected intraperitoneally or stereotactically at the VTA and SN of the rat brain. The behavior features of animals were investigated using hole and board test and apomorphine-induced rotations. HE pathology, the immunoreactivity of tyrosine hydroxylase, DAT, VMAT2and ubiquitin in the brains were observed by immunohistochemistry.Results Behavior investigation indicated that both fenpropathrin intraperitoneal injection and stereotactic injection can induce a decreased activity. Apomorphine could induced rotation of the stereotactic injection group. Immunohistochemistry study suggested that the tyrosine hydroxylase, VMAT2immunoreactivity were decreased in subtantia nigra. While DAT immunoreactivity were decreased in subtantia nigra. And ubiquitin-positive cells were found in fenpropathrin-induced PD models. Organ toxicity was observed in subcutaneously injected models but not in stereotactically injected PD models.Conclusion Long-tern exposure of fenpropathrin could model some of the lesions of PD in rats.