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JNK CASCADE ASSOCIATED WITH APOPTOSIS IN SH-SY5Y CELLS
Wednesday, 14 December 2011 / Parkinsonism and Related Disorders 18S2 (2012) S161–S234
PQ+ by either a reducing agent or NADPH oxidase in microglia, it readily enters cells through DAT to induce oxidative stress and cytotoxicity. Cultured cells or mutant mice with loss of DAT function significantly attenuated neurotoxicity induced by this toxicant. In addition to DAT, PQ+ is also a substrate for the organic cation transporter 3 (Oct3), which is abundantly expressed in nigrostriatal non-dopaminergic cells. In mice with Oct3 deficient, enhanced nigrostriatal damage was detected – perhaps due to reduced buffering capacity of PQ+ and hence, more is available for dopaminergic neurons. This study provides a novel mechanism by which DAT and Oct3 modulate nigrostriatal neurodegeneration induced by PQ2+ . 3.107 PARAQUAT ACTIVATES THE IRE1/ASK1/JNK CASCADE ASSOCIATED WITH APOPTOSIS IN SH-SY5Y CELLS I. Son1 , W. Yang2 , E. Tiffany-Castiglioni3 , Y. Kim4 , M. Lee1 . 1 Dept of Neurology & Inam Neuroscience Research Center, 2 Inam Neuroscience Research Center, Sanbon Hospital, College of Medicine, Wonkwang University, Gunpo, Republic of Korea; 3 Department of Integrative Biosciences and Faculty of Toxicology, Texas A&M University, College Station, TX, USA; 4 Dept of Neurology & Inam Neuroscience Research Center, Sung-Ae General Hospital, Seoul, Republic of Korea Introduction: Epidemiologic and laboratory studies suggest that paraquat can be an environmental etiologic factor in Parkinson’s disease (PD). One mechanism by which paraquat may mediate cell death of dopaminergic neurons is by inducing endoplasmic reticulum (ER) stress, as suggested in a recent report. In this study, we further investigated this linkage by examining ER stress cascades. Objectives: To this aim, human neuroblastoma cells (SH-SY5Y cells) were treated with paraquat and the signaling cascades through which ER stress results in apoptosis were examined. Then, it was examined whether ER stress is produced by paraquat. Paraquat increased ER stress biomarker proteins, glucose-regulated protein 78 (GRP78), ER degradation-enhancing alpha-mannosidaelike protein (EDEM), and C/EBP homologous protein (CHOP). Then, it was investigated which ER stress cascades are affected by paraquat. Paraquat activated inositol-requiring enzyme 1 (IRE1), apoptosis signal regulating kinase 1 (ASK1), and c-jun kinase (JNK). Also, paraquat activated calpain and caspase 3, but did not affect the levels of intracellular calcium and the activity of caspase 12. Finally, apoptotic DNA damage by paraquat was investigated and this damage was attenuated by salubrinal (ER stress inhibitor), thioredoxin (ASK1 inhibitor) and SP600125 (JNK inhibitor). Conclusion: Therefore, current data indicate that paraquat activates the IRE1/ASK1/JNK cascade associated with apoptosis in SY5Y cells. 3.108 ELECTROPHYSIOLOGY OF NEOSTRIATAL NEURONS IN A RAT MODEL OF PARKINSON’S DISEASE INDUCED BY PARAQUAT AND MANEB D. He, H. Xu, R. Chen, X. Cai, N. Chen, A. Zhu. Lab of Neurotoxicology, Department of Environmental Science, East China Normal University, Shanghai, China Background and aim: Neostriatum plays an important role in pathophysiology of Parkinson’s disease (PD). However, the changes of firing activity of neostriatal neurons in PD have been less addressed in vivo. In the present study, we aim to explore the firing activity of neostriatal neurons in a rat model of Parkinson’s disease induced by paraquat and maneb. Methods: Rats were exposed to paraquat or combination of paraquat and maneb for 6 weeks by intraperitoneal injection. It was observed the behavior of animals in declined-plane, vertical-grid and open-field test. Morphology of Substantia nigral neurons were investigated by HE pathology. Spontaneous discharges of neostriatal neurons were recorded using extracellular single-unit recording methods. Results: Compared to the control group and before exposure, both the numbers of animals sliding down from the declined-plane
S191
and the latency of rats’moving on the vertical-grid significantly increased, and autonomic movement decreased significantly. The neural loss in SNc was respectively 43% and 71% in two exposure groups. Three types of neostriatal neurons were recorded including medium spiny-like neurons (MSNs), large aspiny-like neurons (LANs) and fast-spiking interneurons. In the exposed rats, the elevated firing activity was revealed including increased firing activity of neostriatal neurons and more fast-spiking neurons as compared to control rats. Conclusion: The co-exposure of praquart and maneb could induce like-Parkinsonism and nerual loss of SNc. The stronger neostriatal output was modulated by the collection of MSNs and interneurons in PD. Our results illustrate the electrophysiological changes of in vivo neostriatal neurons in Parkinson’s disease. 3.109 EFFECT OF CHRONIC ADMINISTRATION OF SODIUM SALICYLATE ON THE MOTOR FUNCTIONS IN THE ROTENONE INDUCED PD MODEL B. Nehru. Biophysics, Panjab University, Chandigarh, India Sodium salicylate (SS) has been shown to be neuroprotective in various neurodegenerative diseases including Parkinson’s disease due to its free radical scavenging properties. Our study was aimed at studying the efficacy of SS on the chronic PD model, developed by administration of rotenone at the dose of 2 mg/kg body wt. over a period of 5 week. Another group was given SS dissolved in saline by i.p. injection at dose of 50 mg/kg body wt. along with the rotenone treatment. Control group that received the vehicle for rotenone as well as SS and one group receiving SS only were also run along. The animals were monitored regularly for the body weight changes and alterations in the motor behaviour parameters. The rotenone treated animals showed a significant decline in the body weight compared to control over the period of 5 week and SS conjunctive treatment was not able to improve the body weight profile. However, the results of the catalepsy bar test showed a very sharp improvement with SS administration. This observation was also confirmed by the Ludolph scale ratings. Both these parameters showed a declining trend in rotenone treated animals after 3 week, but with SS treatment there was a delay in the onset of these motor dysfunctions. Measurement of Dopamine levels, which is a gold standard for PD, was carried out by HPLC. Its turnover was significantly increased by rotenone treatment showing faster degradation of Dopamine. However, SS treatment could not alter the levels of Dopamine. 3.110 ROTENONE INDUCED NIGROSTRIATAL DEGENERATION IN RODENTS AS A MODEL FOR NEUROPROTECTIVE STRATEGIES FOR PARKINSON’S DISEASE A. Norazit1,2 , M.N. Nguyen2,3 , C. Dickson2 , B.L. Cavanagh2 , A. Mackay-Sim2 , A. Meedeniya3,4 . 1 Department of Molecular Medicine, University of Malaya, Kuala Lumpur, Malaysia; 2 National Centre for Adult Stem Cell Research, Griffith University, Brisbane, 3 Health Institute, Griffith University, Gold Coast, 4 Eskitis Institute for Cell and Molecular Therapies, Griffith University, Brisbane, QLD, Australia Introduction: Rotenone, a mitochondrial complex 1 inhibitor causes oxidative damage via production of reactive oxygen species. Infusion of rotenone into the medial forebrain bundle showed that neurons are lost through chronic oxidative stress and surviving neurons show histopathology similar to the post-mortem human Parkinson’s substantia nigra. Further, the response of glia together with the slow degenerative changes provides a useful backdrop for testing therapeutic interventions, including neuroprotective agents. Objectives: To test the use of the rotenone model for neuroprotective strategies for Parkinson’s disease using a combination of vascular endothelial growth factor (VEGF) and platelet derived
PQ+ by either a reducing agent or NADPH oxidase in microglia, it readily enters cells through DAT to induce oxidative stress and cytotoxicity. Cultured cells or mutant mice with loss of DAT function significantly attenuated neurotoxicity induced by this toxicant. In addition to DAT, PQ+ is also a substrate for the organic cation transporter 3 (Oct3), which is abundantly expressed in nigrostriatal non-dopaminergic cells. In mice with Oct3 deficient, enhanced nigrostriatal damage was detected – perhaps due to reduced buffering capacity of PQ+ and hence, more is available for dopaminergic neurons. This study provides a novel mechanism by which DAT and Oct3 modulate nigrostriatal neurodegeneration induced by PQ2+ . 3.107 PARAQUAT ACTIVATES THE IRE1/ASK1/JNK CASCADE ASSOCIATED WITH APOPTOSIS IN SH-SY5Y CELLS I. Son1 , W. Yang2 , E. Tiffany-Castiglioni3 , Y. Kim4 , M. Lee1 . 1 Dept of Neurology & Inam Neuroscience Research Center, 2 Inam Neuroscience Research Center, Sanbon Hospital, College of Medicine, Wonkwang University, Gunpo, Republic of Korea; 3 Department of Integrative Biosciences and Faculty of Toxicology, Texas A&M University, College Station, TX, USA; 4 Dept of Neurology & Inam Neuroscience Research Center, Sung-Ae General Hospital, Seoul, Republic of Korea Introduction: Epidemiologic and laboratory studies suggest that paraquat can be an environmental etiologic factor in Parkinson’s disease (PD). One mechanism by which paraquat may mediate cell death of dopaminergic neurons is by inducing endoplasmic reticulum (ER) stress, as suggested in a recent report. In this study, we further investigated this linkage by examining ER stress cascades. Objectives: To this aim, human neuroblastoma cells (SH-SY5Y cells) were treated with paraquat and the signaling cascades through which ER stress results in apoptosis were examined. Then, it was examined whether ER stress is produced by paraquat. Paraquat increased ER stress biomarker proteins, glucose-regulated protein 78 (GRP78), ER degradation-enhancing alpha-mannosidaelike protein (EDEM), and C/EBP homologous protein (CHOP). Then, it was investigated which ER stress cascades are affected by paraquat. Paraquat activated inositol-requiring enzyme 1 (IRE1), apoptosis signal regulating kinase 1 (ASK1), and c-jun kinase (JNK). Also, paraquat activated calpain and caspase 3, but did not affect the levels of intracellular calcium and the activity of caspase 12. Finally, apoptotic DNA damage by paraquat was investigated and this damage was attenuated by salubrinal (ER stress inhibitor), thioredoxin (ASK1 inhibitor) and SP600125 (JNK inhibitor). Conclusion: Therefore, current data indicate that paraquat activates the IRE1/ASK1/JNK cascade associated with apoptosis in SY5Y cells. 3.108 ELECTROPHYSIOLOGY OF NEOSTRIATAL NEURONS IN A RAT MODEL OF PARKINSON’S DISEASE INDUCED BY PARAQUAT AND MANEB D. He, H. Xu, R. Chen, X. Cai, N. Chen, A. Zhu. Lab of Neurotoxicology, Department of Environmental Science, East China Normal University, Shanghai, China Background and aim: Neostriatum plays an important role in pathophysiology of Parkinson’s disease (PD). However, the changes of firing activity of neostriatal neurons in PD have been less addressed in vivo. In the present study, we aim to explore the firing activity of neostriatal neurons in a rat model of Parkinson’s disease induced by paraquat and maneb. Methods: Rats were exposed to paraquat or combination of paraquat and maneb for 6 weeks by intraperitoneal injection. It was observed the behavior of animals in declined-plane, vertical-grid and open-field test. Morphology of Substantia nigral neurons were investigated by HE pathology. Spontaneous discharges of neostriatal neurons were recorded using extracellular single-unit recording methods. Results: Compared to the control group and before exposure, both the numbers of animals sliding down from the declined-plane
S191
and the latency of rats’moving on the vertical-grid significantly increased, and autonomic movement decreased significantly. The neural loss in SNc was respectively 43% and 71% in two exposure groups. Three types of neostriatal neurons were recorded including medium spiny-like neurons (MSNs), large aspiny-like neurons (LANs) and fast-spiking interneurons. In the exposed rats, the elevated firing activity was revealed including increased firing activity of neostriatal neurons and more fast-spiking neurons as compared to control rats. Conclusion: The co-exposure of praquart and maneb could induce like-Parkinsonism and nerual loss of SNc. The stronger neostriatal output was modulated by the collection of MSNs and interneurons in PD. Our results illustrate the electrophysiological changes of in vivo neostriatal neurons in Parkinson’s disease. 3.109 EFFECT OF CHRONIC ADMINISTRATION OF SODIUM SALICYLATE ON THE MOTOR FUNCTIONS IN THE ROTENONE INDUCED PD MODEL B. Nehru. Biophysics, Panjab University, Chandigarh, India Sodium salicylate (SS) has been shown to be neuroprotective in various neurodegenerative diseases including Parkinson’s disease due to its free radical scavenging properties. Our study was aimed at studying the efficacy of SS on the chronic PD model, developed by administration of rotenone at the dose of 2 mg/kg body wt. over a period of 5 week. Another group was given SS dissolved in saline by i.p. injection at dose of 50 mg/kg body wt. along with the rotenone treatment. Control group that received the vehicle for rotenone as well as SS and one group receiving SS only were also run along. The animals were monitored regularly for the body weight changes and alterations in the motor behaviour parameters. The rotenone treated animals showed a significant decline in the body weight compared to control over the period of 5 week and SS conjunctive treatment was not able to improve the body weight profile. However, the results of the catalepsy bar test showed a very sharp improvement with SS administration. This observation was also confirmed by the Ludolph scale ratings. Both these parameters showed a declining trend in rotenone treated animals after 3 week, but with SS treatment there was a delay in the onset of these motor dysfunctions. Measurement of Dopamine levels, which is a gold standard for PD, was carried out by HPLC. Its turnover was significantly increased by rotenone treatment showing faster degradation of Dopamine. However, SS treatment could not alter the levels of Dopamine. 3.110 ROTENONE INDUCED NIGROSTRIATAL DEGENERATION IN RODENTS AS A MODEL FOR NEUROPROTECTIVE STRATEGIES FOR PARKINSON’S DISEASE A. Norazit1,2 , M.N. Nguyen2,3 , C. Dickson2 , B.L. Cavanagh2 , A. Mackay-Sim2 , A. Meedeniya3,4 . 1 Department of Molecular Medicine, University of Malaya, Kuala Lumpur, Malaysia; 2 National Centre for Adult Stem Cell Research, Griffith University, Brisbane, 3 Health Institute, Griffith University, Gold Coast, 4 Eskitis Institute for Cell and Molecular Therapies, Griffith University, Brisbane, QLD, Australia Introduction: Rotenone, a mitochondrial complex 1 inhibitor causes oxidative damage via production of reactive oxygen species. Infusion of rotenone into the medial forebrain bundle showed that neurons are lost through chronic oxidative stress and surviving neurons show histopathology similar to the post-mortem human Parkinson’s substantia nigra. Further, the response of glia together with the slow degenerative changes provides a useful backdrop for testing therapeutic interventions, including neuroprotective agents. Objectives: To test the use of the rotenone model for neuroprotective strategies for Parkinson’s disease using a combination of vascular endothelial growth factor (VEGF) and platelet derived