Protective effects of quercetin against hydrogen peroxide-induced apoptosis in human neuronal SH-SY5Y cells

Hydrogen peroxide (H₂O₂) is a major reactive oxygen species that has been implicated in various neurodegenerative diseases. Quercetin, one of the plant flavonoids, has been reported to harbor various physiological properties including antioxidant activity. In this study, we investigated the neuroprotective effects of quercetin against H₂O₂-induced apoptosis in human neuronal SH-SY5Y cells. H₂O₂-mediated cytotoxicity and lactate dehydrogenase release were suppressed in a quercetin concentration-dependent manner. In addition, quercetin repressed the expression of the pro-apoptotic Bax gene and enhanced that of the anti-apoptotic Bcl-2 gene in SH-SY5Y cells. Moreover, quercetin effectively inhibited the activation of the caspase cascade that leads to DNA fragmentation, a key feature of apoptosis, and subsequent cell death. These results indicate the importance of quercetin in protecting against H₂O₂-mediated neuronal cell death. Thus, quercetin might potentially serve as an agent for prevention of neurodegenerative diseases caused by oxidative stress and apoptosis.     

依达拉奉通过microRNA-25抑制高糖诱导的SH-SY5Y细胞凋亡

目的:探讨依达拉奉通过微小RNA-25(microRNA-25,miR-25)对高糖诱导的人神经母细胞瘤SHSY5Y细胞凋亡的抑制作用及其机制。方法:将SH-SY5Y细胞用含高浓度葡萄糖的DMEM培养基和依达拉奉的联合培养液共同培养24 h。MTT比色法测定SH-SY5Y细胞存活率;DCFH-DA荧光探针法检测SH-SY5Y细胞中活性氧簇(ROS)的水平;采用流式细胞术检测SH-SY5Y细胞的凋亡率;Western blot法检测凋亡相关蛋白Bax和Bcl-2的表达水平;实时定量PCR检测细胞中miR-25的表达水平。为进一步阐明依达拉奉抑制高糖诱导的神经细胞凋亡的作用靶点,我们将miR-25抑制剂应用于细胞,之后采用caspase-3凋亡试剂盒检测细胞的凋亡率。结果:与对照组相比,高糖诱导后细胞存活率明显降低,细胞中的ROS水平和细胞凋亡率明显升高,Bax的表达明显增加,Bcl-2的表达明显降低,miR-25的表达水平也明显降低。给予依达拉奉治疗之后,细胞存活率明显升高,ROS含量和细胞凋亡率明显降低,Bax的蛋白水平明显降低,Bcl-2蛋白水平明显升高,miR-25的表达水平亦明显升高。进一步给予miR-25抑制剂后,caspase-3的水平明显升高,此时同时给予依达拉奉后并不能抑制高糖引起的神经细胞的凋亡。结论:依达拉奉对高糖诱导的SH-SY5Y细胞凋亡具有抑制作用,其作用靶点可能是miR-25。     

Glutathione S-transferase pi regulates UV-induced JNK signaling in SH-SY5Y neuroblastoma cells

Activation of c-Jun N-terminal kinase (JNK) signaling pathway is a key event in apoptosis. The cellular mechanisms underlying the control of JNK catalytic activity before and immediately after stress in neuronal cells are still not completely understood. Under resting conditions the basal activity of JNK is low, since JNK is kept inactive by the presence of one or more endogenous repressors, including glutathione S-transferase pi (GSTpi). The aim of this study was to investigate the control of JNK signaling by GSTpi. We examined the modifications of GSTpi protein expression and oligomerization after UV irradiation-induced stress in human SH-SY5Y neuroblastoma cells. In parallel, we investigated the effect of UV irradiation on JNK activation and c-Jun phosphorylation, and whether apoptosis represents a functional consequence triggered by this signaling pathway. We show that in SH-SY5Y cells JNK phosphorylation and activation precedes c-Jun phosphorylation and caspase-3 cleavage. Importantly, the increase of JNK enzymatic activity correlates with the dissociation of GSTpi–JNK complexes and the increased concentration of GSTpi multimer forms. Results presented herein show for the first time direct interaction between JNK and GSTpi in SH-SY5Y neuroblastoma cells, and suggest that in these cells GSTpi may serve as a regulator of JNK catalytic activity. This work contributes to further elucidate the mechanisms underlying the regulation of JNK activity under stress conditions.     

肿瘤抑制剂GA对SH-SY5Y细胞凋亡的影响及分子机制研究

为了探讨HSP90特异的功能抑制剂geldanamycin(GA)能否用于神经母细胞瘤的临床治疗 ,通过检测未分化的和全反式维甲酸 (RA)诱导分化的神经母细胞瘤SH SY5Y细胞在不同浓度GA处理后的细胞存活率 ,发现GA呈剂量依赖性诱导SH SY5Y细胞凋亡 ,但是分化细胞对同样剂量的GA不是很敏感 [细胞存活率依次为 (82 0±6 0 ) %比较 (6 5 0± 3 0 ) % ,P <0 0 2 ;(6 7 9± 3 1) %比较 (4 3 4± 3 9) % ,P <0 0 3;(4 3± 0 8) %比较 (0 4±0 1) % ,P <0 0 5 ]。Western印迹分析和免疫荧光实验显示 ,GA能抑制细胞中c Jun和c Fos的表达 ,并且GA剂量越高 ,其抑制越明显 ;同时GA也诱导了p5 3的核聚集。与未分化细胞相比 ,在相同剂量GA处理后分化细胞中c Jun和c Fos的表达均比未分化细胞略高 ;但是分化细胞中p5 3的核聚集却不如前者明显。提示未分化细胞对同样剂量的GA比分化细胞更敏感 ,可能与分化细胞能抵抗GA引起的c Jun、c Fos的降低以及p5 3的核聚集有关。     

抑制miR-181a对鱼藤酮诱导的SH-SY5Y多巴胺能细胞损伤的保护作用

目的:通过抑制mi R-181a表达研究其对鱼藤酮诱导SH-SY5Y的细胞损伤、内质网应激以及未折叠蛋白反应(unfolded protein response,UPR)的影响,为mi R-181a在帕金森病治疗方面提供初步的实验依据。方法:不同浓度的鱼藤酮诱导SH-SY5Y作用12、24、48、72 h;mi R-181a类似物和mi R-181a抑制剂及0.4μmol/L鱼藤酮诱导SH-SY5Y作用24 h;采用CCK-8法检测细胞存活率;Annexin V/PI双染检测细胞凋亡;双荧光素酶报告基因检测mi R-181a与葡萄糖调节蛋白78(glucose regulated protein 78 k D,GRP78)的靶标关系;q RT-PCR检测mi R-181a和GRP78 m RNA表达水平;Western Blot检测GRP78、肌醇需酶1α(inositol-requiring enzyme 1,IRE1α)、X-盒结合蛋白1(X box-binding protein 1,XBP1)和CCAAT/增强子结合蛋白同源蛋白(CCAAT/enhancer-binding protein-homologous protein,CHOP)的蛋白表达水平。结果:(1)CCK-8结果显示:随着鱼藤酮浓度(0.1μmol/L)增加,SH-SY5Y存活率降低,并存在浓度和时间依赖性;其中0.4μmol/L作用24 h后存活率已降为0.6(P0.05),加入mi R-181a抑制剂后细胞存活率升高达0.8(P0.05);(2)Annexin V/PI双染结果显示:抑制mi R-181a表达,细胞的凋亡降低至0.23(P0.05);(3)双荧光素酶报告基因检测显示:mi R-181a与GRP78存在直接的靶标关系;(4)q RT-PCR结果显示:0.4μmol/L鱼藤酮作用24 h后细胞mi R-181a呈高表达(P0.05),抑制mi R-181a表达可上调GRP78 m RNA水平(P0.05);(5)Western Blot结果显示:抑制mi R-181a表达可上调GRP78和下调p IRE1α、XBP1和CHOP的蛋白表达(P0.05)。结论:抑制mi R-181a表达可减轻鱼藤酮诱导的SH-SY5Y细胞损伤,其机制可能通过上调GRP78进而调节内质网应激以及抑制UPR相关信号通路,从而发挥对神经元细胞的保护作用。     

Resistance to geldanamycin-induced apoptosis in differentiated neuroblastoma SH-SY5Y cells

Geldanamycin (GA) is a specific inhibitor of the 90 kDs heat shock protein (Hsp90) in the cytoplasm of mammalian cells, which binds directly to Hsp90 and promotes proteolytic degradation of its client proteins. As an antitumor drug, GA antagonizes the protecting effects of Hsp90 on cell survival, while its mechanisms remain unclear. Here, we show that GA induces apoptosis in a human neuroblastoma cell line, SH-SY5Y. Treatment of the cells with all trans retinoic acid (RA) generates a neuron-like, morphological change of differentiation, and results in the activation of ERK and Akt pathways, an inhibition of the nuclear translocation of p53 induced by GA, and induces higher resistance to the GA-induced apoptosis. These results provide the first evidence for the requirement of p53 nucleation in SH-SY5Y cells to counteract GA in neuron survival.     

miR-449a过表达抑制人神经母细胞瘤细胞SH-SY5Y增殖并促进其凋亡

目的探讨miR-449a对人神经母细胞瘤细胞系SH-SY5Y的增殖和凋亡的影响。方法用Lipofectamine TM2000将miR-449a模似物或miR-449a对照转染至SH-SY5Y细胞,分为空白、miR-449a模似物和miR-449a对照SHSY5Y细胞组;实时荧光定量PCR(q-PCR)检测各组细胞中miR-449a表达;CCK8法检测细胞增殖;流式细胞仪检测细胞凋亡和周期,Western blot检测c-Myc蛋白和Bax/Bcl-2蛋白表达。结果 miR-449a模似物瞬时转染SH-SY5Y细胞后,miR-449a的表达水平明显高于正常对照组(P0.05);SH-SY5Y细胞增殖能力受到明显抑制(P0.05);凋亡率明显增加(P0.05);c-Myc蛋白表达显著降低(P0.05);细胞促凋亡蛋白Bax表达升高;抗凋亡蛋白Bcl-2表达降低(P0.05)。结论 miR-449a可通过c-Myc影响SH-SY5Y细胞的增殖和周期,通过调节Bax/Bcl-2影响其凋亡。     

孕酮减轻ATP诱导的SH-SY5Y细胞损伤

目的:探讨孕酮对抗腺苷三磷酸(ATP)诱导的人神经母细胞瘤SH-SY5Y细胞损伤的神经保护作用和机制。方法:取对数生长期的SH-SY5Y细胞按照孕酮或ATP浓度的不同进行分组,CCK-8法检测细胞存活率,YO-PRO-1染色检测细胞膜通透性,Fluo-3染色检测细胞内Ca~(2+)浓度的变化,Western blot法检测嘌呤能P2X_7受体表达的变化。结果:与对照组相比,不同浓度(1、3、5和7 mmol/L)ATP作用2 h,SH-SY5Y细胞存活率显著降低(P0.05),细胞摄入YO-PRO-1的荧光强度明显增加(P0.05),且呈剂量依赖性。浓度为3、10和30 nmol/L的孕酮预孵育30 min可减轻ATP损伤作用,细胞存活率较单纯ATP组明显升高(P0.05或P0.01)。孕酮(30nmol/L)或P2X_7受体拮抗剂KN-62(500 nmol/L)预孵育30 min均可显著抑制ATP诱导的胞内YO-PRO-1的荧光增强(P0.01),而孕酮和KN-62两者之间没有明显差异。正常组细胞内钙离子含量少,ATP组细胞内钙离子荧光强度较对照组明显增高(P0.05),孕酮(30 nmol/L)或KN-62(500 nmol/L)预孵育30 min可明显降低(P0.05)ATP诱导的胞内钙荧光增强,而孕酮和KN-62两者之间的作用无明显差异。ATP组SH-SY5Y细胞P2X_7受体表达较对照组明显增加(P0.05),而孕酮(30 nmol/L)预孵育30 min则可显著降低ATP诱导的P2X_7受体表达(P0.05)。结论:孕酮可抑制ATP诱导的P2X_7受体表达、膜孔形成和胞内Ca~(2+)升高,降低细胞死亡率,明显减轻高浓度ATP对SH-SY5Y细胞的损伤作用。     

铁离子对神经母细胞瘤细胞tau蛋白磷酸化的影响

目的研究细胞外铁离子对SH-SY5Y细胞增殖及tau蛋白磷酸化状态的影响。方法 SH-SY5Y细胞于铁离子环境中培养5～30min后,检测其细胞形态、细胞周期以及胞内tau-1表达的变化。结果 MTT检测细胞OD值随铁离子浓度与作用时间的增加而减少。流式细胞术未发现细胞出现凋亡。低浓度铁离子作用后tau-1免疫荧光强度明显增强,高浓度铁离子或长时间作用后,荧光强度则降低。结论铁离子对SH-SY5Y细胞有增殖抑制作用,与浓度和时间相关;低浓度铁离子可导致胞内去磷酸化tau蛋白表达增多,但不会诱导细胞凋亡。高浓度铁离子作用后胞内去磷酸化tau蛋白表达未见增多。     

Bcl-xl基因克隆及其在SH-SY5Y细胞中的表达

目的研究Bcl-xl基因在SH-SY5Y细胞中的表达。方法构建真核表达载体pIRES2-EGFP/Bcl-xl,采用脂质体介导将重组质粒导入SH-SY5Y细胞,RT-PCR和Western-blot检测外源基因表达。结果本实验成功构建了真核表达载体pIRES2-EGFP/Bcl-xl,并用脂质体介导的方法高效转染SH-SY5Y细胞,RT-PCR显示有Bcl-xlmRNA表达增加,Western-blot显示有32kD的蛋白质表达增加。结论重组质粒pIRES2-EGFP/Bcl-xl经转染能够在SH-SY5Y细胞中高效表达,为进一步研究Bcl-xl对SH-SY5Y细胞的生物学功能奠定了基础。     

Hypoxia and reoxygenation increased BACE1 mRNA and protein levels in human neuroblastoma SH-SY5Y cells

Ischemic cerebrovascular diseases, usually involved in hypoxia and reoxygenation, have been reported to increase the risk of dementia such as Alzheimer's disease (AD). β-site amyloid protein precursor (APP)-cleaving enzymes (BACE1) have been identified to participate in the secretion of β-amyloid peptides (Aβ), and its expressive alteration would contribute to the AD neuropathology. We have investigated the effect of hypoxia (0% O₂, 24 h) and reoxygenation (0 h, 12 h and 24 h after 24 h hypoxia) on BACE1 mRNA and protein levels in human neuroblastoma SH-SY5Y cells. At the same time, we also examined the effect of hypoxia and reoxygenation on APP mRNA and protein levels. We demonstrated that hypoxia and reoxygenation did not alter APP mRNA and protein level, However compared to those of controls, BACE1 mRNA levels were up-regulated by 31.5% (P = 0.028) and 35.1% (P = 0.005) at 12 h and 24 h and the protein levels increased to 22%(P = 0.021), 42% (P = 0.000) and 51.5% (P = 0.000) at 0 h, 12 h and 24 h after reoxygenation, respectively. Thus by up-regulating of BACE1 mRNA and protein level in the neuronal cell, hypoxia may be a linkage in the pathophysiology between cerebravascular diseases and AD.     

Calpastatin reduces calpain and caspase activation in methamphetamine-induced toxicity in human neuroblastoma SH-SY5Y cultured cells

Methamphetamine (METH) is an abused psychostimulant drug that can cause neurotoxicity to dopaminergic cells. It has been demonstrated that METH can induce caspase- and calpain-dependent death cascades. The purpose of the present study was to investigate the functional role of calpastatin, a specific endogenous calpain inhibitor protein, on caspase and calpain activation in METH-induced degeneration in neuroblastoma SH-SY5Y cell cultures. In this study, we found that METH significantly decreased cell viability, tyrosine hydroxylase phosphorylation and calpastatin levels. Supplementation of cells with exogenous calpastatin was able to reverse the toxic effect of METH on reduction in cell viability and tyrosine hydroxylase phosphorylation. METH also significantly increased calpain levels, the formation of calpain-specific breakdown products and cleaved caspase-3 levels; once again, these effects were diminished by pretreating the cells with calpastatin. These data suggest the contribution of calpastatin as a potential regulatory factor for calpain- and caspase-dependent death processes.     

Propofol-Induced Protection of SH-SY5Y Cells against Hydrogen Peroxide Is Associated with the HO-1 via the ERK Pathway

Propofol (2, 6-diisopropylphenol), is an anesthetic and routinely used for the humans sedation during surgery. The potent inducers of phase II detoxifying and antioxidant stress responsive to propofol were investigated. First, a dose of 25-100 µM propofol showed no significant cytotoxicity on SH-SY5Y cells and pre-treatment of SH-SY5Y cells with propofol (25-100 μM) for 8h prevented cell death and maintained cell integrity following exposure to 1 mM hydrogen peroxide by MTT assays. Then, an increase in the generation of ROS following hydrogen peroxide treatment was significantly attenuated by 8 h pre-treatment with propofol. Additionally, the potential roles of ERK, p 38 MAPK and JNK in the regulation of propofol-induced endogenous HO-1 expression in SH-SY5Y cells were estimated by Western blotting assays. Results showed that propofol significantly increased the phosphorylation levels of ERK, p 38 MAPK and JNK and antioxidant stress responsive to propofol was attenuated by the inhibition of ERK signaling biochemical inhibitors. These results suggest that the ERK pathway plays an important role in the regulation of propofol-mediated antioxidant effects in SH-SY5Y cells.     

α-突触核蛋白在体外培养SH-SY5Y细胞内过表达可导致氧应激

目的：观察α-突触核蛋白基因在SH-SY5Y细胞内过表达对细胞的影响。 方法： LipofectAMINE法转染SH-SY5Y细胞，用G418对转基因细胞进行筛选，免疫荧光细胞化学检测α-突触核蛋白表达，氧化应激敏感的荧光素探针DCF-DA对活细胞进行染色后用荧光显微镜和流式细胞仪检测细胞内氧应激状况，还原型谷胱甘肽测定试剂盒通过分光光度计检测细胞内还原型谷胱甘肽水平。 结果： 转染细胞筛选后，细胞呈α-突触核蛋白免疫反应阳性；转α-突触核蛋白基因细胞内存在DCF信号增强和还原型谷胱甘肽水平下降。 结论： α-突触核蛋白过表达可引起细胞内氧应激，表明α-突触核蛋白在帕金森病发病机制中可能起重要作用。     

Mutated recombinant human glucagon-like peptide-1 protects SH-SY5Y cells from apoptosis induced by amyloid-β peptide (1–42)

Accumulation and deposition of amyloid β peptide (Aβ) in the brain causes neuronal apoptosis and eventually leads to Alzheimer's disease (AD). A therapeutic target for AD is to block the cascade reaction induced by Aβ. It has been demonstrated that glucagon-like peptide-1 (GLP-1), which is an endogenous insulinotropic peptide secreted from the gut, binds to its receptor in the brain and possesses neuroprotective effects. Using site-directed mutagenesis and gene recombination techniques, we generated a mutated recombinant human glucagon-like peptide-1 (mGLP-1) which has longer half-life as compared with native GLP-1. This present work aims to examine whether mGLP-1 attenuates Aβ_1–42-mediated cytotoxicity in SH-SY5Y cells and to explore the possible mechanisms. Our data indicate that ≥0.02 ng/ml of mGLP-1 facilitated cell proliferation and 0.1 ng/ml and 0.5 ng/ml of mGLP-1 rescued SH-SY5Y cells from Aβ_1–42-induced apoptosis. Moreover, Aβ_1–42 treatment dramatically stimulated the release of Ca²⁺ from internal calcium stores in SH-SY5Y cells, while mGLP-1 helped to maintain the intracellular Ca²⁺ homeostasis. Aβ_1–42 also significantly increased the expression level of TP53 and Bax genes which are involved in apoptotic pathways, and mGLP-1 decreased Aβ_1–42-induced up-regulation of TP53 and Bax. Since mGLP-1 treatment elevated cytosolic cAMP concentration in SH-SY5Y cells, we postulate that mGLP-1 may exert its influence via binding to GLP-1 receptors in SH-SY5Y cells and stimulating the production of cAMP. These results suggest that mGLP-1 exhibited neuronal protection properties, and could potentially be a novel therapeutic agent for intervention in Alzheimer's disease.     

人参皂苷Re对人神经母细胞瘤SH-SY5Y细胞缺氧复氧损伤的保护作用

目的：探讨人参皂苷Re 对人神经母细胞瘤SH-SY5Y 细胞缺氧复氧损伤的保护作用。 方法：采用缺氧复 氧法制备SH-SY5Y 细胞损伤模型,分为对照组、模型组、Re 6.25 μg/mL 组和Re 12.50 μg/mL 组。采用MTT 法测定细胞存活率,四甲基罗丹明甲酯（TMRM）染色评估细胞线粒体膜电位变化,DAPI 染色观察细胞凋亡 率,并进一步采用免疫印迹检测各组细胞核因子NF-E2 相关因子2（Nrf-2）、Bax 和p53 的蛋白表达。 结果：人 参皂苷Re 对SH-SY5Y 细胞活力无显著影响;缺氧复氧条件下,细胞存活率显著降低,而人参皂苷Re 在6.25、 12.50 μg/mL 浓度下预保护可显著提高细胞存活率。缺氧复氧损伤后,人参皂苷Re 6.25、12.50 μg/mL 能显著提 高SH-SY5Y 细胞的线粒体膜电位水平和抑制SH-SY5Y 细胞的凋亡率。人参皂苷Re 能够提高Nrf-2 的蛋白表达, 抑制Bax 和p53 蛋白的表达。结论：人参皂苷Re 可以抑制缺氧复氧损伤细胞的凋亡和氧化损伤,对缺氧复氧诱导 的神经细胞具有显著的保护作用。     

Homocysteine induced SH-SY5Y apoptosis through activation of NADPH oxidase in U251MG cells

Epidemiological studies have indicated a correlation between homocysteinemia and dementia, including Alzheimer's disease. However, the mechanism by which homocysteine (Hcy) induces neuronal cell death remains unknown. We found that micromolar concentrations of Hcy induced neuroblastoma SH-SY5Y cell death only when co-cultured with glioblastoma U251MG cells. In this culture system, cysteine had no effect on SH-SY5Y cell death. There was an increase in TUNEL-positive cells and loss of mitochondrial membrane potential following treatment with 100 μM Hcy. Addition of conditioned medium prepared from U251MG cells in the presence of 100 μM Hcy also reduced SH-SY5Y cell viability, while this effect was prevented when using conditioned medium from U251MG cells exposed to 100 μM Hcy + apocynin, a specific NADPH oxidase inhibitor. Following exposure to 100 μM Hcy in U251MG cells, expression of Rac1, a compartment of NADPH oxidase, was translocated to the plasma membrane, and the active form of Rac1 was increased. There was no change in peroxide concentration in the medium of U251MG cells after addition of Hcy. Overall, these data suggest that Hcy stimulates Rac1 activation and NADPH oxidase, resulting in superoxide anion production that may induce SH-SY5Y cell apoptosis.     

Ropinirole alters gene expression profiles in SH-SY5Y cells: a whole genome microarray study

Ropinirole (ROP) is a dopamine agonist that has been used as therapy for Parkinson''s disease. In the present study, we aimed to detect whether gene expression was modulated by ROP in SH-SY5Y cells. SH-SY5Y cell lines were treated with 10 µM ROP for 2 h, after which total RNA was extracted for whole genome analysis. Gene expression profiling revealed that 113 genes were differentially expressed after ROP treatment compared with control cells. Further pathway analysis revealed modulation of the phosphatidylinositol 3-kinase (PI3K) signaling pathway, with prominent upregulation of PIK3C2B. Moreover, batches of regulated genes, including PIK3C2B, were found to be located on chromosome 1. These findings were validated by quantitative RT-PCR and Western blot analysis. Our study, therefore, revealed that ROP altered gene expression in SH-SY5Y cells, and future investigation of PIK3C2B and other loci on chromosome 1 may provide long-term implications for identifying novel target genes of Parkinson''s disease.     

红景天苷通过Nrf2/HO-1通路减轻6-OHDA诱导的SH-SY5Y细胞损伤

目的:研究红景天苷(salidroside,Sal)对6-羟基多巴胺(6-OHDA)诱导的SH-SY5Y细胞损伤的保护作用及可能机制。方法:4-甲基偶氮唑蓝(MTT)检测SH-SY5Y细胞活性,CM-H2DCFDA染色检测活性氧(ROS);Western Blot检测核因子E2相关因子2(nuclear factor E2-related factor 2,Nrf2)与血红素氧合酶-1(HO-1)的蛋白表达;结果:与对照组比较,6-OHDA(150μmol/L)处理SH-SY5Y 24 h后,细胞存活率降低至44.1%±4.6%(P0.05),ROS水平增加;红景天苷(25,50μmol/L)预处理24 h后,与6-OHDA组比较,细胞存活率分别增加至68.3%±4.1%(P0.05)和80.0%±6.2%(P0.01)同时ROS减少。此外,6-OHDA(150μmol/L)可使细胞内Nrf2与HO-1的蛋白表达减少,红景天苷预处理24 h后,Nrf2与HO-1的蛋白表达依次增加。结论:Sal能减少细胞内ROS的水平,对6-OHDA诱导的SH-SY5Y细胞凋亡具有浓度依赖性的保护作用,其作用机制可能与激活Nrf2/HO-1通路有关。     

Estrogen stimulates activity-regulated cytoskeleton associated protein (Arc) expression via the MAPK- and PI-3K-dependent pathways in SH-SY5Y cells

Activity-regulated cytoskeleton associated protein (Arc) is known to be induced by synaptic plasticity following memory consolidation. Since estrogen has been shown to play an important role in synaptogenesis, a key aspect of the synaptic plasticity, we aimed to study the effects of estrogen on Arc expression in SH-SY5Y human neuroblastoma cells. Using quantitative real-time PCR, Western blot, and confocal immunocytochemistry techniques we found that estrogen markedly increased Arc mRNA and protein expression in SH-SY5Y cells. Estrogen-activated Arc expression was mediated via mitogen-activated protein kinase (MAPK) and phosphoinositide-3 kinase (PI-3K), but not protein kinase C (PKC) and Rho-associated kinase (ROCK), and in the estrogen receptor (ER)-dependent manner. Estrogen also significantly upregulated the dendritic spine scaffolding protein, postsynaptic density-95 (PSD-95), as well as expression of the presynaptic vesicle protein, synaptophysin. Our findings demonstrate the possible mechanisms of estrogen-induced synaptic plasticity, as well as memory consolidation.