Gastrodiae Rhizoma-Uncariae Ramulus cum Uncis is the most frequently used herbal pair in the treatment of Parkinson's disease(PD). Gastrodin and isorhynchophylline are important components of Gastrodiae Rhizoma-Uncariae Ramulus cum Uncis herb pair with anti-Parkinson mechanism. This study aimed to investigate the effect of gastrodin combined with isorhynchophylline on 1-methyl-4-phenylpyridinium(MPP~+)-induced apoptosis of PC12 cells and their antioxidant mechanism. The leakage of lactate dehydrogenase(LDH) from cells to media was analyzed by spectrophotometry. Apoptotic cells were labeled with Annexin V-fluorescein isothiocyanate(FITC) and propidium iodide(PI) and analyzed by flow cytometry. The cell cycle was analyzed using propidium iodide(PI) staining. Lipid peroxidation(LPO) level was analyzed by spectrophotometry. The mRNA expression of caspase-3 was examined by Real-time RT-PCR. The protein expressions of heme oxygenase 1(HO-1) and NADPH: quinoneoxidore-ductase 1(NQO-1) were determined by Western blot. Gastrodin combined with isorhynchophylline reduced the percentage of Annexin V-positive cells and cell cycle arrest in MPP~+-induced PC12 cells. Gastrodin combined with isorhynchophylline down-regulated the mRNA expression of caspase-3, up-regulated the protein expressions of HO-1 and NQO-1, and reduced LPO content in MPP~+-induced PC12 cells. PD98059, LY294002 or LiCl could partially reverse these changes pretreated with gastrodin combined with isorhynchophylline, suggesting that gastrodin combined with isorhynchophylline inhibited MPP~+-induced apoptosis of PC12 cells and oxidative stress through ERK1/2 and PI3 K/GSK-3β signal pathways. Our experiments showed that gastrodin combined with isorhynchophylline could down-re-gulate the mRNA expression of caspase-3 and up-regulate the protein expressions of HO-1 and NQO-1, so as to reduce oxidative stress and inhibit apoptosis.
1-Methyl-4-phenylpyridinium/toxicity* ; Animals ; Antioxidants ; Apoptosis ; Benzyl Alcohols ; Cell Survival ; Glucosides ; Glycogen Synthase Kinase 3 beta ; Oxindoles ; PC12 Cells ; Rats

OBJECTIVE: Mitophagy is known to contribute towards progression of Parkinson's disease. Korean red ginseng (KRG) is a widely used medicinal herb in East Asia, and recent studies have reported that KRG prevents 1-methyl-4-phenylpyridinium ion (MPP METHODS: SH-SY5Y cells were incubated with KRG for 24 h, and subsequently exposed to MPP RESULTS: MPP CONCLUSION KRG effectively prevents MPP
1-Methyl-4-phenylpyridinium/toxicity* ; Apoptosis ; Cell Line, Tumor ; Mitochondria ; Mitophagy ; Panax ; Reactive Oxygen Species

The aim of this study was to investigate the effect of edaravone (Eda) on the balance of mitochondrial fusion and fission in Parkinson's disease (PD) cell model. A cell model of PD was established by treating PC12 cells with 500 μmol/L 1-methyl-4-phenylpyridinium (MPP). Thiazole blue colorimetry (MTT) was used to detect the effect of different concentrations of Eda on the survival rate of PC12 cells exposed to MPP. The mitochondrial morphology was determined by laser confocal microscope. Western blot was used to measure the protein expression levels of mitochondrial fusion- and fission-related proteins, including OPA1, MFN2, DRP1 and Fis1. The results showed that pretreatment with different concentrations of Eda antagonized MPP-induced PC12 cell damage in a dose-dependent manner. The PC12 cells treated with MPP showed mitochondrial fragmentation, up-regulated DRP1 and Fis1 protein expression levels, and down-regulated MFN2 and OPA1 protein expression levels. Eda could reverse the above changes in the MPP-treated PC12 cells, but did not affect Fis1 protein expression. These results suggest that Eda has a protective effect on the mitochondrial fusion disruption induced by MPP in PC12 cells. The mechanism may be related to the up-regulation of OPA1/MFN2 and down-regulation of DRP1.
1-Methyl-4-phenylpyridinium ; Animals ; Dynamins ; Edaravone ; pharmacology ; GTP Phosphohydrolases ; Mitochondria ; drug effects ; Mitochondrial Dynamics ; Mitochondrial Proteins ; PC12 Cells ; Parkinson Disease ; Rats ; Up-Regulation

BACKGROUND: Parkinson's disease is a neurodegenerative disorder, and recent studies suggested that oxidative stress contributes to the degeneration of dopamine cell in Parkinson's disease. Glutamine also has a positive role in reducing oxidative stress damage. In this study, we hypothesized that glutamine offers protection against oxidative stress injury in 1-methyl-4-phenylpyridinium (MPP)-induced Parkinson's disease cell model. METHODS: MPP was used to induce PD models in PC12 cells and classified into control, M0 (MPP), G0 (glutamine), and M0+G0 groups. CCK-8 and AO/EB staining assays were used to examine cell proliferation and apoptosis, respectively. Western blotting was applied to examine the protein expression of PI3K, P-Akt, Akt, P-mTOR, and mTOR. RESULTS: We showed that glutamine suppressed cytotoxicity induced by MPP in PC12 cells. MPP decreased the superoxide dismutase and glutathione peroxidase activity and increased the malondialdehyde content, which were restored by glutamine. Moreover, MPP increased the expression of PI3K, P-Akt, Akt, P-mTOR, and mTOR, which were inhibited by glutamine. And the antioxidant capacity of glutamine on PC12 cells could be improved by LY294002 and inhibited by IGF-1. CONCLUSION These results suggest that glutamine strengthens the antioxidant capacity in PC12 cells induced by MPP through inhibiting the activation of the PI3K/Akt signaling pathway. The effects of glutamine should be investigated and the protective mechanism of glutamine in PD must be explored in future studies.
1-Methyl-4-phenylpyridinium ; administration & dosage ; Analysis of Variance ; Animals ; Cell Culture Techniques ; Disease Models, Animal ; Glutamine ; pharmacology ; Oxidative Stress ; drug effects ; Parkinson Disease ; Phosphatidylinositol 3-Kinases ; metabolism ; Protective Agents ; pharmacology ; Proto-Oncogene Proteins c-akt ; metabolism ; Rats

PURPOSE: Parkinson's disease (PD) is a common age-dependent neurodegenerative disease. MiR-212 has been demonstrated to exert protective effects in several neurological disorders. The present study aimed to investigate the role and underlying molecular mechanism of miR-212 in PD. MATERIALS AND METHODS: 1-methyl-4-phenylpyridinium (MPP+)-induced SH-SY5Y cells were applied as a PD model in vitro. RTqPCR was used to measure the expression of miR-212 and Kruppel-like factor 4 (KLF4) mRNA. Western blot analysis was performed to detect the protein levels of KLF4, Notch1 and Jagged1. Cell viability and apoptosis were determined by the Cell Counting Kit-8 and flow cytometry, respectively. Quantitative analysis of caspase-3 activity, lactate dehydrogenase (LDH), reactive oxygen species (ROS), superoxide dismutase (SOD), tumor necrosis factor-α (TNF-α), and interleukin-1 beta (IL-1β) was conducted with corresponding ELISA kits. Dual-luciferase reporter assay was employed to evaluate the relationship between miR-212 and KLF4. RESULTS: MiR-212 was downregulated in MPP+-induced SH-SY5Y cells. Also, miR-212 alleviated MPP+-induced SH-SY5Y cell damage, embodied by increased cell viability, decreased caspase-3 activity, LDH release, ROS production, TNF-α, and IL-1β expression, as well as elevated SOD levels. KLF4 was a direct target of miR-212, and miR-212 repressed KLF4 expression in a post-transcriptional manner. Moreover, miR-212-mediated protection effects were abated following KLF4 expression restoration in MPP+-induced SH-SY5Y cells, represented as lowered cell viability and enhanced apoptotic rate. Furthermore, Notch signaling was involved in the regulation of miR-212/KLF4 axis in MPP+-induced SH-SY5Y cells. CONCLUSION: miR-212 might attenuate MPP+-induced neuronal damage by regulating KLF4/Notch signaling pathway in SH-SY5Y cells, a promising target for PD therapy.
1-Methyl-4-phenylpyridinium ; Apoptosis ; Blotting, Western ; Caspase 3 ; Cell Count ; Cell Survival ; Enzyme-Linked Immunosorbent Assay ; Flow Cytometry ; In Vitro Techniques ; Interleukin-1beta ; L-Lactate Dehydrogenase ; Necrosis ; Nervous System Diseases ; Neurodegenerative Diseases ; Neurons* ; Parkinson Disease ; Reactive Oxygen Species ; RNA, Messenger ; Superoxide Dismutase

As an environmental risk factor, psychological stress may trigger the onset or accelerate the progression of Parkinson's disease (PD). Here, we evaluated the effects of acute restraint stress on striatal dopaminergic terminals and the brain metabolism of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), which has been widely used for creating a mouse model of PD. Exposure to 2 h of restraint stress immediately after injection of a low dose of MPTP caused a severe loss of striatal dopaminergic terminals as indicated by decreases in the dopamine transporter protein and dopamine levels compared with MPTP administration alone. Both striatal 1-methyl-4-phenylpyridinium ion (MPP) and MPTP concentrations were significantly increased by the application of restraint stress. Striatal monoamine oxidase-B, which catalyzes the oxidation of MPTP to MPP, was not changed by the restraint stress. Our results indicate that the enhanced striatal dopaminergic terminal loss in the stressed mice is associated with an increase in the transport of neurotoxin into the brain.
1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine ; metabolism ; 1-Methyl-4-phenylpyridinium ; metabolism ; Animals ; Corpus Striatum ; drug effects ; metabolism ; Disease Models, Animal ; Dopaminergic Neurons ; drug effects ; MPTP Poisoning ; chemically induced ; metabolism ; Male ; Mice ; Mice, Inbred C57BL ; Neurotoxins ; metabolism ; Restraint, Physical ; Stress, Psychological ; metabolism

BACKGROUND: The extract and hemiterpene glycosides of Ilex Rotunda Thunb exert antioxidant and anti-inflammatory effects. The effect of rotundarpene on apoptosis in neuronal cells caused by the 1-methyl-4-phenylpyridinium (MPP⁺) has not been reported previously. METHODS: Using differentiated PC12 cells and human neuroblastoma SH-SY5Y cells, we investigated the effect of rotundarpene on MPP⁺-caused apoptosis in relation to the cell death process. RESULTS: MPP⁺-induced cell death was identified using the MTT and neutral red uptake tests. Apoptosis was induced by eliciting decreases in the cytosolic levels of Bid and Bcl-2 proteins, increases in the cytosolic levels of Bax and p53, disruption of the mitochondrial transmembrane potential, and the release of cytochrome c and the activation of caspase-8, -9, and -3 in differentiated PC12 cells and SH-SY5Y cells. Treatment with rotundarpene reduced the MPP⁺-induced changes in the levels of apoptosis-regulated proteins, formation of reactive oxygen species, depletion and oxidation of glutathione, and cell death in both PC12 and SH-SY5Y cells. CONCLUSIONS: Rotundarpene may reduce MPP⁺-induced apoptosis in neuronal cells by suppressing the activation of the mitochondria-mediated pathway and the caspase-8 and Bid pathways. Rotundarpene appears to act by inhibiting the production of reactive oxygen species and by the depletion and oxidation of glutathione.
1-Methyl-4-phenylpyridinium ; Animals ; Apoptosis ; Caspase 8 ; Cell Death* ; Cytochromes c ; Cytosol ; Glutathione ; Glycosides ; Humans ; Ilex ; Membrane Potentials ; Neuroblastoma ; Neurons ; Neutral Red ; PC12 Cells ; Reactive Oxygen Species

Icariin is the major bioactive component of Epimedium and has been demonstrated to be a potential drug for age-related diseases. The present study was aimed to investigate the neuroprotective properties of icariin against 1-methyl-4-phenylpyridinium ion (MPP)-induced neurotoxicity in MES23.5 cells and the possible mechanisms. MTT assay showed that treatment with MPPattenuated the cell viability in a dose-dependent manner in MES23.5 cells. Icariin pretreatment resulted in an enhancement of survival. Immunocytochemistry analysis revealed that icariin treatment attenuated MPP-induced loss of tyrosine hydroxylase (TH) positive cells. Meanwhile, Western blot confirmed MPPsignificantly decreased the TH protein expression, and icariin pretreatment could reverse the toxic effect of MPP. Moreover, flow cytometry showed that MPP-induced decrease of the mitochondrial membrane potential could be partly restored by icariin. Furthermore, real-time RT-PCR and Western blot analysis demonstrated that icariin treatment restored the MPP-induced up-regulation of Bax and down-regulation of Bcl-2 mRNA and protein expressions. Western blot data also revealed the inhibitory effect of icariin on MPP-induced up-regulation of cleaved caspase-3. These findings provide the evidence that icariin has neuroprotective properties against MPP-induced neurotoxicity in MES23.5 cells and the mechanism might be related to the anti-apoptotic action of icariin.
1-Methyl-4-phenylpyridinium ; Animals ; Apoptosis ; Caspase 3 ; Cell Line ; Cell Survival ; Down-Regulation ; Flavonoids ; pharmacology ; Membrane Potential, Mitochondrial ; Mitochondria ; Neuroprotective Agents ; pharmacology ; Neurotoxicity Syndromes ; RNA, Messenger ; Up-Regulation

We previously demonstrated that 1-methyl-4-phenylpyridinium (MPP+) causes caspase-independent, non-apoptotic death of dopaminergic (DA) neuronal cells. Here, we specifically examined whether change of glucose concentration in culture medium may play a role for determining cell death modes of DA neurons following MPP+ treatment. By incubating MN9D cells in medium containing varying concentrations of glucose (5~35 mM), we found that cells underwent a distinct cell death as determined by morphological and biochemical criteria. At 5~10 mM glucose concentration (low glucose levels), MPP+ induced typical of the apoptotic dell death accompanied with caspase activation and DNA fragmentation as well as cell shrinkage. In contrast, MN9D cells cultivated in medium containing more than 17.5 mM (high glucose levels) did not demonstrate any of these changes. Subsequently, we observed that MPP+ at low glucose levels but not high glucose levels led to ROS generation and subsequent JNK activation. Therefore, MPP+-induced cell death only at low glucose levels was significantly ameliorated following co-treatment with ROS scavenger, caspase inhibitor or JNK inhibitor. We basically confirmed the quite similar pattern of cell death in primary cultures of DA neurons. Taken together, our results suggest that a biochemically distinct cell death mode is recruited by MPP+ depending on extracellular glucose levels.
1-Methyl-4-phenylpyridinium ; Cell Death* ; DNA Fragmentation ; Dopaminergic Neurons* ; Glucose* ; Neurons ; Parkinson Disease ; Reactive Oxygen Species

OBJECTIVETo investigate the effects of paeonol on neuron cell model of Parkinson disease (PD).

METHODSThe cell model of Parkinson disease was induced by treatment of 1-Methyl-4-phenylpyridinium (MPP+) in PC12 cells, the PD model cells were treated with 1 μmol/L, 3 μmol/L or 9 μmol/L paeonol for 24h, respectively. Cell viability and LDH leakage were detected by MTT and lactate dehydrogenase (LDH) assay; the apoptosis of PC12 cells was assessed by Hoechst 33258 staining and flow cytometry; reactive oxygen species (ROS) production was detected by DCFH-DA method; and the ratio of Bax/Bcl-2 and activation of caspase-3 were determined by Western blotting.

RESULTSMPP+ treatment significantly reduced cell viability, increased LDH leakage, enhanced the proportion of apoptotic cells and ROS production. In addition, MPP+ treatment dramatically increased the Bax/Bcl-2 ratio, and the activation of caspase-3. Compared to PD model group, paeonol treatment significantly enhanced cell viability, decreased LDH leakage, inhibited the proportion of apoptotic cells and ROS production, reduced the Bax/Bcl-2 ratio and the activated caspase-3 protein.

CONCLUSIONPaeonol can prevent PC12 cells from apoptosis induced by MPP+, and the mechanism may be associated with the down-regulation of ROS production, Bax/Bcl-2 ratio and Caspase-3 activation.

1-Methyl-4-phenylpyridinium ; Acetophenones ; pharmacology ; Animals ; Apoptosis ; Caspase 3 ; metabolism ; Cell Survival ; Down-Regulation ; Fluoresceins ; Neuroprotective Agents ; pharmacology ; PC12 Cells ; Parkinson Disease ; drug therapy ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; Rats ; Reactive Oxygen Species ; metabolism ; bcl-2-Associated X Protein ; metabolism