Korean red ginseng decreases 1-methyl-4-phenylpyridinium-induced mitophagy in SH-SY5Y cells / 中西医结合学报

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

Antioxidant mechanism of gastrodin combined with isorhynchophylline in inhibiting MPP~+-induced apoptosis of PC12 cells / 中国中药杂志

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.

SNHG1 promotes MPP+-induced cytotoxicity by regulating PTEN/AKT/mTOR signaling pathway in SH-SY5Y cells via sponging miR-153-3p

BACKGROUND: Long non-coding RNA small molecule RNA host gene 1 (SNHG1) was previously identified to be relevant with Parkinson's disease (PD) pathogenesis. This work aims to further elucidate the regulatory networks of SNHG1 involved in PD. Methods: 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-hydrochloride (MPTP)-induced mice and 1-methyl-4-phenylpyridinium (MPP+)-treated SH-SY5Y cells were respectively constructed as the in vivo and in vitro PD models. Expression levels of SNHG1 and miR-153-3p were detected by qRT-PCR. Protein expression levels of phosphate and tension homology deleted on chromosome ten (PTEN) were measured by western blotting assay. Cell viability and apoptosis were determined by MTT and flow cytometry assays. The interactions among SNHG1, miR-153-3p and PTEN were identified by luciferase reporter assay, RNA immunoprecipitation, and/or RNA pull-down analysis. RESULTS: Increased SNHG1 expression was found in midbrain of MPTP-induced PD mice and MPP+-treated SH-SY5Y cells. Overexpression of SNHG1 lowered viability and enhanced apoptosis in MPP+-treated SH-SY5Y cells. Moreover, SNHG1 acted as a molecular sponge to inhibit the expression of miR-153-3p. Furthermore, miR-153-3p-mediated suppression of MPP+-induced cytotoxicity was abated following SNHG1 up-regulation. Additionally, PTEN was identified as a direct target of miR-153-3p, and SNHG1 could serve as a competing endogenous RNA (ceRNA) of miR-153-3p to improve the expression of PTEN. Besides, enforced expression of PTEN displayed the similar functions as SNHG1 overexpression in regulating the viability and apoptosis of MPP+-treated SH-SY5Y cells. Finally, SNHG1 was found to activate PTEN/AKT/mTOR signaling pathway in SH-SY5Y cells by targeting miR-153-3p. CONCLUSION: SNHG1 aggravates MPP+-induced cellular toxicity in SH-SY5Y cells by regulating PTEN/AKT/mTOR signaling via sponging miR-153-3p, indicating the potential of SNHG1 as a promising therapeutic target for PD.

Protective effect of edaravone on balance of mitochondrial fusion and fission in MPP-treated PC12 cells / 生理学报

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.

Glutamine protects against oxidative stress injury through inhibiting the activation of PI3K/Akt signaling pathway in parkinsonian cell model

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.

MiR-212 Attenuates MPP+-Induced Neuronal Damage by Targeting KLF4 in SH-SY5Y Cells

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.

Acute Restraint Stress Augments 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine Neurotoxicity via Increased Toxin Uptake into the Brain in C57BL/6 Mice / 神经科学通报·英文版

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.

Icariin protects against MPP-induced neurotoxicity in MES23.5 cells / 生理学报

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.

Inhibitory Effect of Rotundarpene on Parkinsonian Neurotoxin 1-Methyl-4-Phenylpyridinium-Induced Apoptotic Cell Death

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.

Neuroprotective effects of paeonol in a cell model of Parkinson disease / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To investigate the effects of paeonol on neuron cell model of Parkinson disease (PD).</p><p><b>METHODS</b>The 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.</p><p><b>RESULTS</b>MPP+ 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.</p><p><b>CONCLUSION</b>Paeonol 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.</p>

Glucose Levels in Culture Medium Determine Cell Death Mode in MPP+-treated Dopaminergic Neuronal Cells

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.

Functional Role of Parkin against Oxidative Stress in Neural Cells

BACKGROUND: Parkinson disease (PD) is caused by selective cell death of dopaminergic neurons in the substantia nigra. An early onset form of PD, autosomal recessive juvenile parkinsonism has been associated with a mutation in the parkin gene. The function of parkin is known to remove misfolding proteins and protect cell death. We aimed to investigate the role of parkin against oxidative stress in neuronal cells. METHODS: Parkin knockout embryonic stem cells (PKO ES cells) were differentiated into neurons by adherent monolayer culture method. Oxidative stress was induced by the treatment of 1-methyl-4-phenylpyridinium (MPP+) in neurons derived from wild type and PKO ES cells, and cell viability was examined by MTT assay. After exposure to MPP+, Tuj1-positive cell population was compared between PKO and wild type cells by fluorescence activated cell sorter (FACS) analysis. The activated caspase3 protein level was also measured by Western blot analysis, FACS and immunocytochemistry. RESULTS: There was no difference in the efficiency of neuronal differentiation between wild type and PKO ES cells. After exposure to MPP+, no significant differences were found in cell viability and Tuj1-positive cell population between the two groups determined by MTT assay and FACS analysis, respectively. The activated caspase3 protein levels examined by Western blot analysis, FACS and immunocytochemistry were not changed in PKO cells compared with those of wild type cells after MPP+ treatment. CONCLUSION: These results suggest that PKO neuronal cells including dopaminergic neurons are not sensitive to caspase3-dependent cell death pathway during the response against MPP+-induced oxidative stress.

Neuroprotective Effect of Chebulagic Acid via Autophagy Induction in SH-SY5Y Cells

Autophagy is a series of catabolic process mediating the bulk degradation of intracellular proteins and organelles through formation of a double-membrane vesicle, known as an autophagosome, and fusing with lysosome. Autophagy plays an important role of death-survival decisions in neuronal cells, which may influence to several neurodegenerative disorders including Parkinson's disease. Chebulagic acid, the major constituent of Terminalia chebula and Phyllanthus emblica, is a benzopyran tannin compound with various kinds of beneficial effects. This study was performed to investigate the autophagy enhancing effect of chebulagic acid on human neuroblastoma SH-SY5Y cell lines. We determined the effect of chebulagic acid on expression levels of autophagosome marker proteins such as, DOR/TP53INP2, Golgi-associated ATPase Enhancer of 16 kDa (GATE 16) and Light chain 3 II (LC3 II), as well as those of its upstream pathway proteins, AMP-activated protein kinase (AMPK), mammalian target of rapamycin (mTOR) and Beclin-1. All of those proteins were modulated by chebulagic acid treatment in a way of enhancing the autophagy. Additionally in our study, chebulagic acid also showed a protective effect against 1-methyl-4-phenylpyridinium (MPP+) - induced cytotoxicity which mimics the pathological symptom of Parkinson's disease. This effect seems partially mediated by enhanced autophagy which increased the degradation of aggregated or misfolded proteins from cells. This study suggests that chebulagic acid is an attractive candidate as an autophagy-enhancing agent and therefore, it may provide a promising strategy to prevent or cure the diseases caused by accumulation of abnormal proteins including Parkinson's disease.

Inhibitory Effect of 3,4,5-Tricaffeoylquinic Acid on Parkinsonian Toxin 1-Methyl-4-phenylpyridinium-induced Apoptosis

BACKGROUND: 1-Methyl-4-phenylpyridinium (MPP+) causes a neuronal cell injury that is similar to the findings observed in Parkinson's disease. Caffeoylquinic acid derivatives have demonstrated anti-oxidant and anti-inflammatory effects. Nevertheless, the effect of 3,4,5-tricaffeoylquinic acid (3,4,5-triCQA) on the neuronal cell death due to exposure of parkinsonian toxin MPP+ remains unclear. METHODS: Using differentiated PC12 cells, the preventive effect of 3,4,5-triCQA on the MPP+-induced cell death in relation to apoptotic process was examined. RESULTS: MPP+ induced a decrease in Bid, Bcl-2 and survivin protein levels, increase in Bax levels, loss of the mitochondrial transmembrane potential, cytochrome c release, activation of caspases (-8, -9 and -3), cleavage of PARP-1, and an increase in the tumor suppressor p53 levels. 3,4,5-Tricaffeoylquinic acid attenuated the MPP+-induced changes in the apoptosis-related protein levels, formation of reactive oxygen species, depletion of GSH, nuclear damage and cell death. 3,4,5-Tricaffeoylquinic acid attenuated another parkinsonian neurotoxin rotenone-induced cell death. CONCLUSIONS: 3,4,5-Tricaffeoylquinic acid may attenuate the MPP+-induced apoptosis in PC12 cells by suppressing the activation of the mitochondrial pathway and the caspase-8- and Bid-dependent pathways. The preventive effect seems to be ascribed to its inhibitory effect on the formation of reactive oxygen species and depletion of GSH.

Protective effects of crude polysaccharides from Chroogomphus rutilus on SH-SY5Y cells impaired by MPP(+) / 生理学报

The aim of the present study was to investigate the protective effects of crude polysaccharides from Chroogomphus rutilus on dopaminergic neurons impaired by MPP(+). SH-SY5Y cells were pretreated with crude polysaccharides (200, 400 and 800 μg/mL), and then MPP(+) was added to cell medium. After 48 h of incubation, MTT method was used to detect the survival rate of SH-SY5Y cells damaged by MPP(+). Annexin V-FITC staining and flow cytometry were used to detect apoptotic rate. The results showed that pretreating SH-SY5Y cells with crude polysaccharides (400 and 800 μg/mL) increased the survival rates, and reduced the apoptotic rates of SH-SY5Y cells. To rule out the possibility that crude polysaccharides may decrease actual concentration of MPP(+) by direct binding, we washed off crude polysaccharides before MPP(+) addition. Under this experimental condition, MTT results showed the survival rates of the SH-SY5Y cells were still significantly increased by 800 μg/mL crude polysaccharides pretreatment. These results suggest a protective effect of polysaccharides on the SH-SY5Y cells. Most of this protection is contributed by direct action of polysaccharides on the cells, not by binding with MPP(+). It is indicated that the crude polysaccharides from Chroogomphus rutilus can be developed as a potential drug for Parkinson's disease prevention and treatment in the future.

Role of calcium dyshomeostasis in 1-methyl-4-phenylpyridinium ion-induced apoptosis of human neuroblastoma SH-SY5Y cells / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the role of calcium dyshomeostasis in 1-methyl-4-phenylpyridinium ion (MPP⁺)-induced apoptosis of human neuroblastoma SH-SY5Y cells.</p><p><b>METHODS</b>The viability of SH-SY5Y cells exposed to varying concentrations of MPP⁺ was assessed using MTT colorimetric assay, and MPP⁺-induced cell apoptosis was detected with hoechst 33342 staining and Annexin V+PI assay. Western blotting and rhodamine 123 staining were employed to examine the changes in cellular poly(ADP-ribose) polymerase (PARP) protein expression and mitochondrial membrane potential in response to MPP⁺ exposure. The effects of ruthenium red and/or MPP⁺ on calcium concentration in the cytoplasm, mitochondria and endoplasmic reticulum were evaluated using confocal microscopy.</p><p><b>RESULTS</b>MPP⁺ induced apoptosis and caused reduced cell viability and mitochondrial membrane potential in SH-SY5Y cells. The cells exposed to MPP⁺ showed a lowered calcium concentration in the cytoplasm and endoplasmic reticulum and an increased mitochondrial Ca²⁺ uptake. Ruthenium red rescued MPP⁺-induced apoptosis and mitochondrial membrane potential reduction, reduced PARP cleavage, and inhibited the increase of mitochondrial matrix free Ca²⁺ in the cells exposed to MPP⁺.</p><p><b>CONCLUSION</b>Mitochondrial calcium overload plays an important role in MPP⁺-induced apoptosis of SH-SY5Y cells, which is closely associated with dysregulation of intracellular Ca²⁺ homeostasis.</p>

Protective effect of six Kaixin San formulas on nerve cells injured by different materials / 中国中药杂志

<p><b>OBJECTIVE</b>To investigate the protective effect of six Kaixin San formulas on simulated cells model of depression, Alzheimer's disease and Parkinson's disease.</p><p><b>METHOD</b>The in vitro simulated cells model of depression, Alzheimer's disease and Parkinson's disease was established by injuring SH-SY5Y cells with corticosterone (0.4 mmol x L(-1)) , injuring PC12 cells with neurotoxic amyloid peptide (Abeta25-35) (20 micromol x L(-1)) and injuring SH-SY5Y cells with 1-methyl-4-phenylpyridinium ion (MPP+) (250 micromol x L(-1)). The cell survival rate was assayed with MTT method and the degree of cell injury was detected with LDH.</p><p><b>RESULT</b>100, 500 mg x L(-1) Dingzhixiao Wan prepared as mentioned in Beiji Qianjin Yaofang could significantly increase the survival ratio of SH-SY5Y cells injured by corticosterone and reduce LDH concentration released. All of the Kaixin San formulas could significantly increase the survival ratio of PC12 cells injured by Abeta25-35 and reduce LDH concentration released. Particularly, Kaixin San (10, 100, 500 mg L(-1)) prepared as mentioned in Beiji Qianjin Yaofang shown the best effect. And 500 mg x L(-1) Fushen Wan prepared as mentioned in Gujin Luyan could significantly increase survival ratio of SH-SY5Y cell injured by MPP and reduce LDH concentration released.</p><p><b>CONCLUSION</b>Dingzhixiao Wan prepared as mentioned in Beiji Qianjin Yaofang could protect corticosterone-induced SH-SY5Ycells injury, showing a potential antidepressant effect. All of the six Kaixin San formulas could protect Abeta25-35-induced PC12 cells injury, but Kaixin San prepared as mentioned in Beiji Qianjin Yaofang shown the best potential effect for Alzheimer's disease. Fushen Wan prepared as mentioned in Gujin Luyan could protect MPP(+)-induced SH-SY5Y cells injury to some extent.</p>

Protective effects of puerarin against 1-methyl-4-phenylpyridinium-induced mitochondrial apoptotic death in differentiated SH-SY5Y cells / 中国中药杂志

It is well known that puerarin possesses protective activity on neurodegenerative diseases. However, the exact path way involved in the protective effect of puerarin on MPP+ -induced cell death is unclear. In this study, we focused on mitochondria im pairment in the apoptotic process of MPP+ -elicited SH-SY5Y cells and detected the protection of puerarin. As evidenced by Trypan blue assay, the cell viability was significantly decreased by 1 mmol x L(-1) MPP+, but reversed by different concentrations puerarin pre treatment. Flow cytometer analysis revealed that MPP+ -induced SH-SY5Y cells apoptosis and arrested the cells in G2/M phase, where as puerarin pretreatment concentration dependently reversed the apoptosis ratio. In addition to the apoptosis ratio, 50.0 micromol x L(-1) puerarin pretreatment even altered the MPP+ -induced G2/M phase arrest. JC-1 assay suggested that MPP+ significantly opened MMP of the SH-SYSY cells; pretreatment with puerarin attenuated the deterioration of the MMP. Both ELISA and Western blotting showed that puerarin prevented the release of cytochrome c from the mitochondrial interior to the cystol elicited by MPP+. DNA ladder showed that typical DNA ladder was present in the MPP+ -induced SH-SY5Y cells. Additionally, MPP+ enhanced caspase-9 and caspase-3 ac tivity, respectively, while not caspase-8. However,the enhancement was concentration dependently blocked by puerarin pretreatment. Taken together, puerarin can modulate mitochondrial membrane potential and inhibit the cytochrome c releasing-caspase cascade to pre vent MPP+ -induced cell injury.

Protective effect of effective part of Acanthopanacis senticosus on damage of PC12 cells induced by MPP+ / 中国中药杂志

The purpose of our research was to evaluate the protective effect of the effective part of Acanthopanacis senticosus (AS) on the damage of PC12 cells induced by MPP+, an in vitro cell model for Parkinson's disease. Cell viability and apoptosis of PC12 cells induced by MPP' were assayed by MTT and flow cytometry respectively in the presence or absence of the effective part of AS. The contents of lactate dehydrogenase (LDH), nitric oxide (NO), nitric oxide synthase (NOS) and malondialdehyde (MDA) were determined by UV spectrophotometer. Our study showed that the survival rate of PC12 cells was markedly increased while cell apoptosis was decreased in the range of 200 to 400 mg x L(-1) of the effective part of AS. The contents of LDH, NO, NOS, MDA were reduced. Our experimental results indicated that the effective part of AS had the protective effect on the damage of PC12 cells induced by MPP+. The underlying mechanisms might be the combination of reduction of LDH leakage and decreases in the contents of NO, NOS and MDA, and finally prevent the apoptosis in PC12 cells and increase the cell survival rate.

Role of Casein Kinase 2 in Parkinsonian Toxin 1-Methyl-4-phenylpyridinium-induced Cell Death

BACKGROUND: Protein casein kinase 2 is involved in signal transduction, cell growth, and apoptosis. However, it has not been elucidated whether parkinsonian toxin 1-methyl-4-phenylpyridinium (MPP+)-induced neuronal cell death is mediated by a casein-kinase-2-mediated pathway. METHODS: We monitored apoptosis-related protein activation, changes in the level of casein kinase 2, nuclear damage, and apoptosis in differentiated PC12 cells exposed to MPP+ in combination with casein kinase 2 inhibitor. RESULTS: Casein kinase 2 inhibitors [4,5,6,7-tetrabromobenzotriazole (TBB), 5,6-dichloro-1-beta-D-ribofuranosylbenzimidazole, and apigenin] reduced MPP+- and rotenone-induced cell death in differentiated PC12 cells. TBB inhibited the MPP+-induced activation of apoptosis-related proteins (decreases in Bid and Bcl-2 levels, increase in Bax levels, cytochrome c release, and caspase-3 activation), increase in casein kinase 2 levels, and nuclear damage. CONCLUSIONS: Administering casein kinase 2 inhibitor TBB at concentrations that do not induce toxic effects may reduce MPP+-induced cell death in differentiated PC12 cells by suppressing the apoptosis-related protein activation that leads to cytochrome c release and subsequent activation of caspase-3. The results suggest that MPP+-induced cell death process is mediated by a casein kinase 2 pathway.