蛇床子素对MPP~＋损伤PC12细胞的保护作用研究

目的观察蛇床子素（osthole）对1-甲基-4-苯基吡啶离子（MPP＋）诱导PC12细胞损伤的神经保护作用。方法将MPP＋加入培养的PC12细胞中,建立多巴胺能神经元损伤模型,加入不同浓度的蛇床子素预处理细胞（0.01、0.05、0.1mmol/L）。处理24h后用噻唑蓝（MTT）比色法检测细胞活性;以乳酸脱氢酶（LDH）活性测定反映细胞的损伤程度;采用Westernblot法检测Bax、Bcl-2蛋白的表达,分析Bax/Bcl-2比值变化,以及检测细胞色素C的改变。结果蛇床子素可以明显减少MPP＋诱导的PC12细胞活性的降低,LDH的释放,Bax/Bcl-2比值的增高以及细胞色素C的释放（P〈0.05）。结论蛇床子素对MPP＋诱导的PC12细胞损伤具有保护作用。     

黄芩苷通过上调lncRNAH19表达来减轻MPP+诱导的PC12细胞神经毒性

目的 探讨黄芩苷是否通过上调长链非编码RNA(Long noncoding RNA,lncRNA)H19表达来减轻1-甲基4-苯基吡啶离子(1-methyl-4-phenylpyridinium,MPP⁺)诱导的PC12细胞神经毒性。方法 分别采用0.5、0.75、1、2 mmol/L MPP⁺和10、20、50和70 μmol/L黄芩苷作用PC12细胞,后续试验使用水平分别选择0.75 mmol/L MPP⁺和50 μmol/L黄芩苷; 以0.75 mmol/L MPP⁺损伤PC12细胞,体外模拟帕金森病,并加入黄芩苷; 采用四甲基偶氮唑盐(Methyl thiazolyl tetrazolium,MTT)进行细胞活力测定,Annexin V-异硫氰酸荧光素(Fluorescein isothiocyanate isomer,FITC)/碘化丙啶(Propidium iodide,PI)双染法进行凋亡定量分析,蛋白质印迹分析(Western blot)检测Pro-天冬氨酸特异性半胱氨酸蛋白酶(Cysteinyl aspartate specific proteinase,Caspase)-3,Cleaved-caspase-3,B细胞淋巴瘤/白血病-2(B cell lymphoma/lewkmia-2,Bcl-2)蛋白和Bcl-2相关X蛋白(Bcl-2 associated X protein,Bax)的相对表达水平,实时定量聚合酶链式反应(Quantitative real-time polymerase chain reaction,qPCR)进行lncRNA H19的相对表达水平检测; 在PC12细胞中转染lncRNA H19小干扰RNA(lncRNA H19 siRNA,si-H19),并加入MPP⁺和黄芩苷,考察PC12细胞增殖、凋亡等变化。结果 与对照组比较,MPP⁺降低PC12细胞的存活率、Bcl-2蛋白、lncRNA H19相对表达水平,提高PC12细胞的凋亡率、Cleaved-caspase-3,Bax蛋白相对表达水平(P<0.05),而Pro-caspase-3蛋白相对表达水平无明显变化(P>0.05)。与MPP⁺组比较,黄芩苷显著提高MPP⁺诱导的PC12细胞的存活率、Bcl-2蛋白、lncRNA H19相对表达水平,降低PC12细胞的凋亡率、Cleaved-caspase-3,Bax蛋白相对表达水平(P<0.05),而Pro-caspase-3蛋白相对表达水平无明显变化(P>0.05)。转染si-H19后黄芩苷和MPP⁺诱导的PC12细胞的存活率、Bcl-2蛋白相对表达水平降低,PC12细胞的凋亡率、Cleaved-caspase-3,Bax蛋白相对表达水平升高(P<0.05),而Pro-caspase-3蛋白相对表达水平无明显变化(P>0.05)。结论 黄芩苷上调lncRNA H19表达,提高MPP⁺诱导的PC12细胞活力和降低其凋亡,减轻MPP⁺诱导的PC12细胞神经毒性。     

丹参川芎嗪注射液对Aβ损伤的PC12细胞保护作用及机制研究

目的 探讨丹参川芎嗪注射液对Aβ损伤的PC12细胞可能的保护作用及机制。方法 将PC12细胞分为5组:空白对照组(未加任何处理药物)、Aβ诱导组(20 μmol/L Aβ处理组)和预处理组(分别加入浓度为5 ml/L、10 ml/L、20 ml/L的丹参川芎嗪注射液孵育24 h后加20 μmol/L Aβ),通过CCK-8法检测细胞增殖活性,流式细胞术(FCM)检测细胞凋亡率,Hoechst 33258染色观察PC12细胞核的改变,荧光分光光度计测定LDH、SOD、GSH及caspase-3活性水平,免疫组织化学方法观察细胞色素C(Cyt-C)蛋白释放水平,Western Blot检测Bcl-2的表达水平。结果 丹参川芎嗪注射液(5、10、20 ml/L)预处理对Aβ诱导的PC12细胞损伤有较好的保护作用,其保护作用随着药物浓度的增加而增强。它能增加Aβ损伤的PC12细胞增殖活力,减少Aβ诱导的PC12细胞凋亡,降低细胞核凝聚现象,抑制Aβ损伤的PC12细胞LDH释放,增强SOD和GSH活性,促进Cyt-C在细胞内表达,降低caspase-3活性,促进Bcl-2的表达。结论 丹参川芎嗪注射液对Aβ诱导的PC12细胞损伤具有与线粒体通路相关的保护作用,其保护作用与它抑制细胞凋亡、抗氧化应激、维持线粒体正常功能、抑制caspase-3的激活、促进抗凋亡因子Bcl-2的表达有关。     

L—dopa诱导PC12细胞凋亡及Bcl—2、Bax表达的改变

目的：探讨L－dopa治疗帕金森病（PD）疗效减退的机制及其毒性作用机制。方法：以PC12细胞为多巴胺神经元的细胞模型,利用PI／HO33342双染结合荧光显微镜技术、电镜技术、流式细胞术及免疫荧光技术检测不同浓度的L-dopa对CPC12铁凋亡诱导作用及凋亡相关基因Bcl-2、Bax表达的改变。结果50、100、150μmol/L不同浓度L－dopa处理组凋亡率分别为12．4％、24．4％、37．2％、PI／HO33342双染可区别凋亡,坏死和正常细胞,且可以见到染色质碎裂;电镜下可见早期凋亡细胞和晚期凋亡细胞,给予L-dopa处理后,Bcl-2的表达量减少,与凋亡率呈显著负相关;Bax的表达量增加,与凋亡率呈显著正相关。结论：L－dopa诱导PC12细胞凋亡且呈量效关系,提示L－dopa可能是通过凋亡途径损害多巴胺神经元导致疗效减退,其机制可能是通过改变Bcl-2/Bax的比值来介导细胞凋亡。     

曲札茋苷对二氯化钴诱导PC12细胞氧化应激的保护作用

目的 探讨曲札茋苷注射液对二氯化钴诱导PC12细胞氧化应激的保护作用及其机制.方法 取对数生长期PC12细胞随机分为5组:对照组、模型组、曲札茋苷低水平组、曲札茋苷高水平组、依达拉奉组;甲基三氯硅烷(Methyltrichlorosilane,MTS)法检测细胞活力:分光光度法检测超氧化物歧化酶(Superox-ide...     

促红细胞生成素对1-甲基-4-苯基吡啶损伤的PC12细胞的保护作用

目的探讨促红细胞生成素（erythropoietin,EPO）对1-甲基-4-苯基吡啶离子（MPP^＋）诱导的PC12细胞,变性损伤的保护作用及机制。方法用MPP^＋处理PC12细胞制作帕金森病细胞模型,采用四甲基偶氮哗监泫检测暴露于不同浓度EPO后细胞的活性;流式细胞术与DNA断端原位标记法（terminal deoxynucleotidyl transferase dUTP nick end labeling,TUNEL）检测各组的细胞凋亡率;免疫印迹法检测不同处理组PC12细胞Bcl-2和Bax的表达,并采用荧光法观察不同处理组PC12细胞活性氧（reactive oxygen species,ROS）与线粒体膜电位水平以及caspase-3活性的变化。结果MPP^＋可以使PC12细胞存活率下降,凋亡率增高;同时PC12细胞内ROS增多,线粒体膜电位下降。MPP^＋还可以明显地提高Bax／Bcl-2比值并激活caspase-3。而EPO可以抑制这些由MPP^＋引发的改变,并在1U／mL时发挥最大保护作用。结论EPO可抑制MPP^＋诱导的PC12绌胞死亡,其作用机制可能其自身抗氧化和抗凋亡的特性有关。     

促红细胞生成素对1-甲基-4-苯基吡啶损伤的PC12细胞的保护作用(英文)

目的探讨促红细胞生成素(erythropoietin,EPO)对1-甲基-4-苯基吡啶离子(MPP+)诱导的PC12细胞变性损伤的保护作用及机制。方法用MPP+处理PC12细胞制作帕金森病细胞模型,采用四甲基偶氮唑蓝法检测暴露于不同浓度EPO后细胞的活性;流式细胞术与DNA断端原位标记法(terminal deoxynucleotidyl transferase dUTPnick end labeling, TUNEL)检测各组的细胞凋亡率;免疫印迹法检测不同处理组PC12细胞Bcl-2和Bax的表达,并采用荧光法观察不同处理组PC12细胞活性氧(reactive oxygen species,ROS)与线粒体膜电位水平以及caspase-3活性的变化。结果 MPP+可以使PC12细胞存活率下降,凋亡率增高;同时PC12细胞内ROS增多,线粒体膜电位下降。MPP+还可以明显地提高Bax/Bcl-2比值并激活caspase-3。而EPO可以抑制这些由MPP+引发的改变,并在1 U/mL时发挥最大保护作用。结论 EPO可抑制MPP+诱导的PC12细胞死亡,其作用机制可能与其自身抗氧化和抗凋亡的特性有关。     

Protective effects of sesamin and sesamolin on hypoxic neuronal and PC12 cells

Reactive oxygen species (ROS) are important mediators of a variety of pathological processes, including inflammation and ischemic injury. The neuroprotective effects of sesame antioxidants, sesamin and sesamolin, against hypoxia or H2O2-induced cell injury were evaluated by cell viability or lactate dehydrogenase (LDH) activity. Sesamin and sesamolin reduced LDH release of PC12 cells under hypoxia or H2O2-stress in a dose-dependent manner. Dichlorofluorescein (DCF)-sensitive ROS production was induced in PC12 cells by hypoxia or H2O2-stress but was diminished in the presence of sesamin and sesamolin. We evaluated further the role of mitogen-activated protein kinases (MAPKs) and caspase-3 in hypoxia-induced PC12 cell death. Extracellular signal-regulated protein kinase (ERK) 1, c-jun N-terminal kinase (JNK), and p38 MAPKs of signaling pathways were activated during hypoxia. We found that the inhibition of MAPKs and caspase-3 by sesamin and sesamolin correlated well with the reduction in LDH release under hypoxia. Furthermore, the hypoxia-induced apoptotic-like cell death in cultured cortical cells as detected by a fluorescent DNA binding dye was reduced significantly by sesamin and sesamolin. Taken together, these results suggest that the protective effect of sesamin and sesamolin on hypoxic neuronal and PC12 cells might be related to suppression of ROS generation and MAPK activation.     

Protective effects of edaravone against cobalt chloride-induced apoptosis in PC12 cells

Objective

To investigate the neuroprotective effects of edaravone (Eda) on cobalt chloride (CoCl₂)-induced oxidative stress and apoptosis in cultured PC12 cells as well as the underlying mechanisms.

Methods

PC12 cells impaired by CoCl₂ were used as the cell model of hypoxia. MTT (methyl thiazolyl tetrazolium) was used to assay the viability of the PC12 cells exposed to Eda with gradient concentrations; Hochest 33258 stain assay was used to analyze the apoptosis ratio of the PC12 cells; Bcl-2 and Bax protein levels in PC12 cells were examined by western blotting. ROS level, the mitochondrial transmembrane potential and caspase-3 activity in each group were detected by spectrofluorometer.

Results

CoCl₂ treatment caused the loss of cell viability in PC12 cells, which was associated with the elevation of apoptotic rate, the formation of ROS and the disruption of mitochondrial transmembrane potential. CoCl₂ also significantly induced the upregulation of Bax/Bcl-2 ratio and the activation of caspase-3. In contrast, Eda significantly reversed these phenotypes, with its maximum protective effect at 0.1 μmol/L.

Conclusion

These results indicated that Eda could protect PC12 cells from CoCl₂-induced cytotoxicity, and this protection might be ascribed to its anti-oxidative and anti-apoptotic activities.     

灵芝多糖对Aβ25-35诱导的PC12细胞损伤的保护性研究

目的观察灵芝多糖(GLP)对β-淀粉样蛋白(Aβ25-35)诱导的PC12细胞损伤的保护作用。方法将Aβ25-35或(和)不同浓度的GLP加入体外培养的PC12细胞中,用MTT检测PC12细胞活力的变化;以DCFH-DA来检测细胞内活性氧(ROS)水平的改变;通过Western Blotting来检测Bcl-2和Bax的表达水平。结果 Aβ25-35处理36h后的PC12细胞存活率仅为对照的60.7%,细胞内ROS水平上升到原来的222.7%,同时Bcl-2/Bax比值下降,为对照组的60.0%。经不同浓度的GLP预处理后,细胞存活率均显著提高,分别能达到69.7%,80.7%和88.3%(P<0.01);10g/ml GLP预处理PC12细胞24h后,细胞内ROS水平下降至正常组的160.6%,Bcl-2/Bax比值升高到93.6%,P值均<0.01。结论 GLP对Aβ25-35诱导的PC12细胞损伤有保护作用。     

Olfactory ensheathing cells conditioned medium prevented apoptosis induced by 6-OHDA in PC12 cells through modulation of intrinsic apoptotic pathways

Olfactory ensheathing cells (OECs) express a high level of growth factors which play a very important role as neuronal support. Recent evidence in literatures showed that transplantation of OECs may improve functional restoration in 6-OHDA-induced rat model of Parkinson's disease (PD). However, the biological function of various factors released from OECs in Parkinson' disease is still unclear. In this study, we examined the effects of newborn rat OECs conditioned medium (CM) on PC12 cells. Cells treated with 6-OHDA underwent cytotoxicity and apoptotic death determined by MTT assay and Hoechst 33342/PI staining. OECs CM was able to reduce the cellular damage in PC12 cells. Further investigation results showed that CM inhibited the disruption of mitochondrial transmembrane potential, up-regulation of Bcl-2 and down-regulation of Bax. Taken together, this study indicates that CM has a neuroprotective effect on 6-OHDA induced apoptosis of PC12 cells, which is through up-regulation of the Bcl-2/Bax ratio and protection for mitochondrion.     

α-tocopherol protects PC12 cells From hyperoxia-induced apoptosis

A rat clonal pheochromocytoma cell line (PC12) was cultured under normoxic (21% O₂) and hyperoxic (50% O₂) conditions. PC12 cells underwent apoptotic cell death when they were cultured in charcoal-stripped medium in a high-oxygen atmosphere. Vitamin E homologs, α-tocopherol (αT), β-tocopherol (βT), γ-tocopherol (γT), and δ-tocopherol (δT), were added to the culture medium to study their biological activities. αT was more effective than γT and δT in preventing hyperoxia-induced cell death. Addition of exogenous αT to charcoal-treated medium prevented lactate dehydrogenase (LDH) leakage from PC12 cells and also inhibited the apoptosis, which was accompanied by DNA fragmentation. Additional αT was rapidly concentrated in PC12 cells, suggesting that it exerts antioxidant effects. Our data show that PC12 cell death under high-oxygen conditions is due to apoptosis and that, among the vitamin E homologs, αT most effectively prevents hyperoxic apoptosis. J. Neurosci. Res. 52:184–191, 1998. © 1998 Wiley-Liss, Inc.     

Dual inhibition of protein phosphatase-1/2A and calpain rescues nerve growth factor-differentiated PC12 cells from oxygen-glucose deprivation-induced cell death

In the present study, we examined how the cell survival signaling via cyclic AMP-responsive element binding protein (CREB) and Akt, and the cell death signaling via cystein proteases, calpain and caspase-3, are involved in oxygen-glucose deprivation (OGD) followed by reoxygenation (OGD/reoxygenation)-induced cell death in nerve growth factor (NGF)-differentiated PC12 cells. OGD/reoxygenation-induced cell death was evaluated by LDH release into the culture medium. The level of LDH release was low (9.0% +/- 4.1%) immediately after 4 hr of OGD (0 hr of reoxygenation), was significantly increased to 28.6% +/- 6.6% at 3 hr of reoxygenation, and remained at similar levels at 6 and 20 hr of reoxygenation, suggesting that reoxygenation at least for 3 hr resulted in the loss of cell membrane integrity. After 4 hr of OGD followed by 3 hr of reoxygenation, dephosphorylation of phosphorylated CREB (pCREB), but not phosphorylated Akt (pAkt), was induced. Under these conditions, calpain- but not caspase-3-mediated alpha-spectrin breakdown product was increased, indicating that OGD/reoxygenation also induced an increase in calpain activity. The restoration of pCREB by protein phosphatase (PP)-1/2A inhibitors or the inhibition of excessive activation of calpain by calpain inhibitor did not reduce OGD/reoxygenation-induced LDH release. Cotreatment with PP-1/2A and calpain inhibitors reduced OGD/reoxygenation-induced LDH release. The present study suggests that a balance in the phosphorylation and proteolytic signaling is involved in the survival of NGF-differentiated PC12 cells.     

Isoflurane and sevoflurane affect cell survival and BCL-2/BAX ratio differently

Depletion of calcium from the neuronal endoplasmic reticulum (ER) induces apoptosis. Isoflurane depletes calcium from sarcoplasmic reticulum (SR) of muscle, an analogue of ER in neurons, while sevoflurane maintains or increases SR calcium. We hypothesized that isoflurane, but not sevoflurane, induces apoptosis by depleting the ER calcium. Rat PC12 pheochromocytoma cells and primary cortical neurons were treated with equipotent doses of isoflurane and sevoflurane. Isoflurane, but not sevoflurane, at equipotent doses induced cell damage determined by both LDH release and MTT reduction assays, dose and time dependently, in both types of cells. Isoflurane at 2.4% for 24 h induced cytotoxicity in both cell types, which was characterized by nuclear condensation and fragmentation and activation of caspases 3 and 9. Isoflurane cytotoxicity was suppressed by dantrolene, a ryanodine receptor antagonist that inhibits abnormal calcium release from the ER. Isoflurane decreased the Bcl-2/Bax ratio by as much as 36% (P < 0.05). However, sevoflurane did not cause neuronal damage by apoptosis nor did it decrease the Bcl-2/Bax ratio. These results suggest that isoflurane and sevoflurane differentially affect the Bcl-2/Bax ratio and cell survival. At equipotent concentrations, isoflurane, but not sevoflurane, induces cytotoxicity in both PC12 cells and primary cortical neurons and decreases the Bcl-2/Bax ratio.     

Protective effects of Ginkgo biloba extract on 6-hydroxydopamine-induced apoptosis in PC12 cells

The present study analyzed the protective effects of Ginkgo biloba extract against 6-hydroxydopamine-induced PC12 cell apoptosis in a model of Parkinson’s disease. The results showed that Ginkgo biloba extract had a potent cytoprotective action and inhibited apoptosis of PC12 cells induced by 6-hydroxydopamine. Ginkgo biloba extract decreased the ratio of Bax to Bcl-2 and markedly inhibited the activation of p53 and caspase-3. These experimental findings indicate that Ginkgo biloba extract may significantly reduce the effects of oxidative stress induced by 6-hydroxydopamine in PC12 cells and suppress cell apoptosis. The potential effects of Ginkgo biloba extract might be greater than those of levodopa in the treatment of Parkinson’s disease.     

大黄酚对神经细胞缺氧损伤的保护作用

目的 观察大黄酚对缺氧PC12细胞损伤的保护作用;方法 培养PC12细胞,建立缺氧致神经细胞损伤模型;缺氧前后四甲基偶氮唑盐法（MTT）检测PC12细胞增殖活性、光镜观察PC12细胞形态、测定上清液中乳酸脱氢酶（LDH）活性、早期癌基因表达产物（c-fos）荧光免疫组化表达和逆转录酶聚合酶链反应（RT-PCR）分析神经型一氧化氮合酶（nNOS）、诱导型一氧化氮合酶（iNOS）mRNA的表达;结果 大黄酚明显改善缺氧PC12细胞的活力,对损伤细胞形态有改善作用,使损伤细胞的培养上清液中的LDH明显减少;c-fos表达减少,PCR结果分析显示nNOS mRNA在缺氧早期表达.iNOSmRNA主要在缺氧晚期表达.结论 本缺氧模型能够引起PC12细胞凋亡现象,大黄酚能减轻PC12细胞缺氧损伤,对神经元细胞有保护作用.     

Atypical antipsychotics attenuate neurotoxicity of beta-amyloid(25-35) by modulating Bax and Bcl-X(l/s) expression and localization

We have demonstrated recently that atypical antipsychotics possess neuroprotective actions in H2O2-mediated and serum-withdrawal models of cell death. In the present study, we compared the ability of atypical and typical antipsychotics to protect against an insult mediated by Abeta(25-35), an apoptogenic fragment of the Alzheimer's disease-related beta-amyloid (Abeta) peptide. Treatment of PC12 cell cultures with Abeta(25-35) did not significantly alter total cellular expression levels of Bax, a proapoptotic Bcl-2 family member, or levels of Bcl-XL, an antiapoptotic analogue. Treatment with Abeta(25-35), however, did result in mitochondrial translocation of Bax, which effectively increased the mitochondrial ratio of Bax to Bcl-X(L). This relative increase in proapoptotic molecules was reduced by pretreatment with atypical (quetiapine and olanzapine) and typical (haloperidol) antipsychotics. We also observed a selective increase in proapoptotic Bcl-XS immunodetection in haloperidol-treated cells, which was evident particularly in the mitochondrial compartment. This increase in proapoptotic molecules may account for the lower neuroprotective potential of haloperidol, as determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium (MTT) reduction assay. The disparate neuroprotective effects of atypical and typical antipsychotics/neuroleptics may be due to their respective abilities to regulate pro- and anti-apoptotic protein translocation and expression.     

Bcl-2 accelerates the neuronal differentiation: new evidence approaching to the biofunction of Bcl-2 in the neuronal system

The proto-oncogene product Bcl-2 is unique in that it inhibits apoptosis rather than promoting cell proliferation. In the present study, we encountered a new possible role of Bcl-2 in the neuronal differentiation. Rat pheochromocytoma PC12 cells have been known as the model of neuronal differentiation by the stimulation of NGF. Bcl-2 transfected PC12 (MB2) cells showed the accelerated neuronal differentiation, as compared with control PC12 (V4) cells. In addition, chemotherapeutic agents Taxol which has been known as neurotoxic compound, induced the acute neuronal cell atrophy and suppressed neuronal differentiation. This neuronal cell atrophy and suppression of neuronal differentiation were not due to apoptotic cell death. Interestingly, Bcl-2 rescued PC12 cells from both neuronal cell atrophy and suppression of neuronal differentiation. Taxol suppressed polymerization between neurofilament light and heavy (NF-L and NF-H), and MB2 cell extract rescued it. We, therefore, suggest the acceleration of polymerization between NF-L and NF-H as the new possible role of Bcl-2.     

The role of phospholipid methylation in 1-methyl-4-phenyl-pyridinium ion (MPP+)-induced neurotoxicity in PC12 cells

Excessive methylation has been proposed to be involved in the pathogenesis of Parkinson's disease (PD), via mechanisms that involve phospholipid methylation. Meanwhile, 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) was found to stimulate phospholipid methylation via the oxidized metabolite, 1-methyl-4-phenyl-pyridinium (MPP+), in the rat brain and liver tissues. In the present study, we investigated the effect of MPP+ on phosphatidylethanolamine N-methyltransferases (PENMT) and the potential role of this pathway in MPP(+)-induced neurotoxicity using PC12 cells. The results obtained indicate that MPP+ stimulated phosphatidylethanolamine (PTE) methylation to phosphatidylcholine (PTC) and correspondingly increased the formation of lysophosphatidylcholine (lyso-PTC). Moreover, the addition of S-adenosylmethionine (SAM) to the cell culture medium increases MPP(+)-induced cytotoxicity. The incubation of 1mM MPP+ and various concentrations of SAM (0-4 mM) decreased the viability of PC12 cells from 80% with MPP+ alone to 38% viability with 4 mM SAM for 4 days incubation. The data also revealed that the addition of S-adenosylhomocysteine (SAH), a methylation inhibitor, offered significant protection against MPP(+)-induced cytotoxicity, indicating that methylation plays a role in MPP(+)-induced cytotoxicity. Interestingly, lyso-PTC showed similar actions to MPP+ in causing many cytotoxic changes with at least 10 times higher potency. Lyso-PTC induced dopamine release and inhibited dopamine uptake in PC12 cells. Lyso-PTC also caused the inhibition of mitochondrial potential and increased the formation of reactive oxygen species in PC12 cells. These results indicate that phospholipid methylation pathway might be involved in MPP+ neurotoxicity and lyso-PTC might play a role in MPP(+)-induced neurotoxicity.