人参皂苷Rg1对H2O2诱导的HaCaT细胞氧化损伤保护作用研究

目的 观察人参皂苷Rg₁对H₂O₂诱导的HaCaT细胞氧化损伤保护作用,并探讨其机制。方法 体外培养HaCaT细胞, H₂O₂诱导细胞建立氧化应激损伤模型,分为空白组、H₂O₂损伤组、人参皂苷Rg₁保护组。细胞增殖与毒性检测试剂盒(CCK-8)检测细胞存活率,Hochest染色法检测细胞凋亡情况,活性氧检测试剂盒测定细胞活性氧(ROS)水平,Western blot检测细胞中caspase-3、caspase-6、caspase-8、GAPDH蛋白表达。结果 H₂O₂诱导HaCaT细胞半数抑制浓度为100 μg?mL^-1;与H₂O₂损伤组比较,5、10和15mg?L^-1人参皂苷Rg₁预处理后,HaCaT细胞存活率明显升高(P<0.05),细胞核皱缩损伤状态明显改善,细胞凋亡数量显著减少。同时,人参皂苷Rg₁预处理可显著降低HaCaT细胞ROS水平,下调凋亡相关标志蛋白-活化型caspase-3、caspase-6、caspase-8蛋白表达水平。结论 人参皂苷Rg₁对H₂O₂诱导的HaCaT细胞氧化应激损伤具有一定的保护作用,其机制可能与增强细胞清除自由基能力及抑制凋亡相关。     

没药甾酮对H2O2损伤PC12细胞的保护作用

探讨没药甾酮(guggulsterone)对氧化应激损伤PC12细胞的保护作用。以过氧化氢(hydrogen peroxide，H₂O₂)损伤PC12细胞为氧化应激损伤模型， 维生素E为对照， 采用四甲基偶氮唑蓝［3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyl-tetrazolium bromide，MTT］法检测细胞增殖状况； 试剂盒检测乳酸脱氢酶(lactate dehydrogenase,LDH)及一氧化氮(nitric oxide，NO)的释放； DCFH法和Fura 2-AM法检测细胞内活性氧(reactive oxygen species，ROS)和Ca²⁺的含量； 碘化丙啶(propidium iodide，PI)染色流式细胞术(flow cytometry，FCM)检测细胞凋亡； 罗丹明123(rhodamine 123，Rh 123)染色FCM检测细胞线粒体膜电位(mitochondrial membrane protential，MMP)。结果表明， 没药甾酮(0.1～10 μmol·L^-1)可使200 μmol·L^-1 H₂O₂作用24 h后的PC12细胞生长抑制率下降； 细胞外LDH和NO， 细胞内ROS和Ca²⁺含量降低； 明显抑制200 μmol·L^-1 H₂O₂作用12 h后诱导的PC12细胞凋亡和线粒体膜电位降低作用，没药甾酮(0.1～10 μmol·L^-1)使细胞凋亡率由24.3%下降至18.4%、 15.9%、 11.8%。实验结果表明, 没药甾酮对氧化应激损伤PC12细胞具有保护作用， 其机制可能为降低细胞内ROS含量， 进而抑制LDH和NO释放， 降低细胞内Ca²⁺含量， 升高线粒体膜电位,减少细胞凋亡。     

脑蛋白水解物对神经细胞损伤修复活力测定方法的研究

目的 评价脑蛋白水解物对H₂O₂诱导的PC12细胞损伤的修复效果,建立一种脑蛋白水解物注射液的生物活性检测方法。方法 以脑蛋白水解物的进口代表药物注射用脑蛋白水解物为例,采用PC12细胞培养,分析不同细胞接种浓度、不同浓度的H₂O₂损伤细胞、不同浓度脑蛋白水解物对抗干预的影响;采用MTT比色法对样品组、对照组和损伤组的细胞进行染色后,用酶标仪测定OD值,计算修复率,以评价脑蛋白水解物对模型细胞PC12损伤的保护作用;同时将该损伤修复评价方法用于国产脑蛋白水解物的生物活性检测。结果 在8×10⁴~12×10⁴·mL^-1细胞接种量、0.5 mmol·L^-1 H2O2损伤浓度下、60 μg·L^-1药物浓度(以含氮量计)下可成功的建立H₂O₂诱导的PC12细胞损伤模型。结论 采用该方法对8批国产脑蛋白水解物注射液样品及注射用脑蛋白水解物进行对比检测,发现对H₂O₂损伤的细胞均具有良好修复作用。     

羟乙基葛根素对过氧化氢致牛脑微血管内皮细胞损伤的保护作用

目的研究牛脑微血管内皮细胞(BCMEC)过氧化损伤机制并探讨羟乙基葛根素对牛脑微血管内皮细胞损伤的保护作用。方法用MTT法和LDH活性检测测定BCMEC的损伤；倒置相差显微镜下一般形态学观察、透射电子显微镜超微结构观察及流式细胞术测定BCMEC凋亡变化。结果H₂O₂ (200 μmol·L^-1)损伤BCMEC后，细胞存活率下降，LDH释放增加，羟乙基葛根素和edaravone可减轻此损伤。H₂O₂ (100 μmol·L^-1)可诱导BCMEC凋亡，羟乙基葛根素 和edaravone对此有保护作用。结论羟乙基葛根素和edaravone对H₂O₂导致的BCMEC坏死和凋亡有保护作用，该作用与其抗氧化作用有关。     

钾通道阻断剂部分抑制三氧化二砷诱导的HeLa细胞死亡

目的研究钾通道阻滞剂对三氧化二砷诱导的HeLa细胞死亡的作用。方法采用MTT法评价HeLa细胞的存活情况，采用膜片钳技术记录HeLa细胞的电压依赖性钾电流。结果As₂O₃(5 μmol·L^-1)孵育24 h引起显著的HeLa细胞死亡，As₂O₃(5 μmol·L^-1)孵育24 h后存活的细胞表现明显的电压依赖性钾电流密度增加。+80 mV电压下，As₂O₃(5 μmol·L^-1)孵育组电流密度(61±18) pA/10 pF(n=8)明显高于对照组(38±10) pA/10 pF(n=8,P<005)。As₂O₃诱导的HeLa细胞死亡可被共同孵育钾通道阻滞剂四氨基吡啶(3 mmol·L^-1)或四乙基铵(5 mmol·L^-1)所部分抑制。3 mmol·L^-1四氨基吡啶或5 mmol·L^-1四乙基铵对HeLa细胞无明显细胞毒作用。结论As₂O₃长期处理增加HeLa细胞的电压依赖性钾电流。As₂O₃诱导的HeLa细胞死亡可被钾通道阻滞剂四氨基吡啶或四乙基铵部分抑制。     

M3受体对体外H2O2诱导大鼠心肌细胞凋亡的保护作用

目的探讨M₃受体激动对H₂O₂诱导的大鼠培养心肌细胞凋亡的作用，进一步阐明其机制。方法末端标记法 (TUNEL)进行细胞凋亡检测；免疫组化方法检测Bcl-2和Fas的表达；共聚焦显微镜观察［Ca²⁺］_i荧光强度变化。结果M₃受体激动剂胆碱(10 mmol·L^-1)可减少H₂O₂诱导的心肌细胞凋亡的数量，并可增加心肌Bcl-2的表达，减少Fas表达，抑制H₂O₂诱导的［Ca²⁺］_i荧光强度的升高。但预先应用4DAMP (10 nmol·L^-1)阻断M₃受体可逆转胆碱作用。结论激动M₃受体对H₂O₂诱导的心肌细胞凋亡有保护作用，其机制可能与Bcl-2和Fas表达以及下调［Ca²⁺］_i有关。     

转录因子Cup2对白念珠菌铜离子代谢、氧化应激调控作用的初步研究

目的 利用白念珠菌（Candida albicans）不同转录因子基因缺失菌,考察参与调控铜离子（Cu²⁺）代谢和氧化应激的重要转录因子。方法 点板实验（spot assay）、生长曲线法。结果 spot assay筛选发现,转录因子Cup2缺失菌Cup2Δ/Δ对Cu²⁺的敏感性增加,进一步研究表明Cup2Δ/Δ在含5 mmol/L的Cu²⁺培养液中生长缓慢;Cup2Δ/Δ对H₂O₂的敏感性也有所增加,而且Cu²⁺协同H₂O₂发挥抑菌作用,在BCS螯合Cu²⁺后,增加了Cup2Δ/Δ和亲本菌SN250对H₂O₂诱导的氧化应激的耐受性。在氟康唑、咪康唑和酮康唑敏感性实验中,Cup2Δ/Δ并未表现出对唑类药物敏感。结论 敲除转录因子Cup2,可增加白念珠菌对Cu²⁺和H₂O₂的敏感性。转录因子Cup2可能参与调控白念珠菌对Cu²⁺的代谢和H₂O₂诱导的氧化应激反应,但并未参与对唑类药物耐药性的调控。     

过氧化氢诱导牛主动脉内皮细胞损伤和胞内Ca2+升高及钙拮抗剂的抑制作用

为探讨缺氧/缺血过程中自由基损伤与钙超载的关系,观察了过氧化氢(H₂O₂)诱导培养牛主动脉内皮细胞(BAEC)的损伤和胞内游离钙([Ca²⁺]i)的变化。结果表明,H₂O₂可剂量、时间依赖地诱导BAEC活性下降(MTT值下降),脂质过氧化产物丙二醛(MDA)生成显著增加,同时伴有[Ca²⁺]i迅速显著升高。钙拮抗剂硝苯地平可剂量依赖地抑制H₂O₂引起的[Ca²⁺]i升高;同时能显著升高BAEC的MTT值,降低MDA生成,有效对抗H₂O₂诱导的BAEC损伤。提示,H₂O₂诱导内皮损伤可能与升高[Ca²⁺]i有关,Ca²⁺超载可能是活性氧致损伤的途径之一。钙拮抗剂对活性氧损伤具有一定保护作用。     

五味子乙素调控小神经胶质BV-2细胞氧化应激损伤的机制研究

目的 研究五味子乙素对H₂O₂诱导小神经胶质BV-2细胞氧化应激损伤的保护作用,并探讨其可能的作用机制。方法 体外常规培养BV-2细胞,用H₂O₂诱导细胞氧化应激损伤模型,将细胞分为正常对照组、模型组、五味子乙素10,20,40 μmol·L^-1组。CCK8试剂盒检测五味子乙素对细胞存活率的影响,相关试剂盒检测细胞匀浆中MDA、NO含量及SOD活性,免疫印迹方法检测Jak2、p-Jak2、State3、p-State3、HO-1及SOD1蛋白表达水平。结果 与模型组相比,不同剂量的五味子乙素可明显增加细胞的存活率、降低氧化应激产物MDA及NO的释放、增强SOD酶活性,差异均有统计学意义（P<0.05）;免疫印迹结果显示五味子乙素可明显提高HO-1、SOD1蛋白水平,并抑制Jak2、State3的磷酸化水平,与模型组相比差异有统计学意义（P<0.05）。结论 五味子乙素可明显降低BV-2细胞的氧化应激损伤,其作用机制可能与抑制Jak2/State3信号通路的活化有关。     

DJ-1保护多巴胺能神经元抵抗过氧化氢氧化应激损伤的研究

目的 探讨DJ-1保护多巴胺能神经元免受过氧化氢(H₂O₂)损伤的机制。 方法 使用神经生长因子(NGF)将大鼠嗜铬细胞瘤细胞(PC12细胞)诱导为多巴胺能神经元模型。H₂O₂处理引起细胞氧化应激损伤模型,CCK-8试剂盒检测细胞活性,DHE染色检测细胞内ROS水平。PI / Hoechst染色检测细胞凋亡,蛋白质免疫印迹法(Western blot)检测DJ-1和TH蛋白的表达。构建DJ-1过表达载体,检测DJ-1对H₂O₂中PC12细胞的保护作用及对细胞内活性氧(ROS)的影响。RT-qPCR检测α-synuclein,p53,Bax,Bcl-2的表达变化。 结果 H₂O₂处理可显着降低PC12细胞的活性,H₂O₂处理24 h以上可引起细胞凋亡。H₂O₂处理下调DJ-1蛋白和TH蛋白的表达,并且在RNA水平上α-突触核蛋白的表达增加。另外 p53, Bax和 caspase-3表达增加, Bcl-2表达减少。DJ-1的过表达可以抑制H₂O₂引起的ROS增加,DJ-1可以维持细胞活性,减少H₂O₂的凋亡。在RNA水平抑制α-突触核蛋白,p53,bax,bcl-2的凋亡和抗凋亡基因表达变化。 结论 DJ-1能够抑制H₂O₂引起的 ROS水平升高,减少α-synuclein积累,抑制 p53,凋亡基因如 bax的表达减弱了多巴胺能神经元中H₂O₂诱导的氧化应激损伤。     

Sinensetin attenuates oxygen–glucose deprivation/reperfusion-induced neurotoxicity by MAPK pathway in human cerebral microvascular endothelial cells

Sinensetin is a polymethoxylated flavone with anti-inflammatory and anti-oxidative activities. This work aimed to explore the function and mechanism of sinensetin in oxygen and glucose deprivation/reperfusion (OGD/R)-induced neurotoxicity. The overlapping target genes of cerebral stroke and sinensetin were determined according to GeneCards and ParmMapper tools and were subjected to Gene Ontology (GO) annotations and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses. Human cerebral microvascular endothelial cells (HCMECs) were stimulated with OGD/R. Neurotoxicity was investigated by Cell Counting Kit-8, lactate dehydrogenase (LDH) release, reactive oxygen species (ROS) level, qRT-PCR, and TUNEL analysis. The proteins (p38, JNK, and ERK) in mitogen-activated protein kinase (MAPK) signaling were measured using Western blotting. Total of 50 overlapping target genes of cerebral stroke and sinensetin were predicted. Pathway analysis showed they might be involved in the MAPK pathway. Sinensetin attenuated OGD/R-induced neurotoxicity by mitigating viability reduction, LDH release, ROS generation, inflammatory response, and apoptosis in HCMECs. Sinensetin weakened OGD/R-induced activation of the MAPK pathway via decreasing the phosphorylation of p38, JNK, and ERK. The pathway inhibitors mitigated the activation of the MAPK signaling, and sinensetin exacerbated this effect. The inhibitors reversed OGD/R-induced neurotoxicity in HCMECs, and sinensetin contributed to this role. Overall, sinensetin prevents OGD/R-induced neurotoxicity through decreasing the activation of MAPK pathway.     

Melatonin prevents endothelial cell pyroptosis via regulation of long noncoding RNA MEG3/miR-223/NLRP3 axis

OBJECTIVE Atherosclerosis(AS) is an inflammatory disease linked to endothelial dysfunction.Melatonin is reported to possess substantial anti-inflammatory properties, which has proven to be effective in AS. Emerging literature suggests that pyroptosis plays a critical role during AS progression. However, whether pyroptosis contributes to endothelial dysfunction and the underlying molecular mechanisms remained unexploited.This study was designed to investigate the antipyroptotic effects of melatonin in atherosclerotic endothelium and to elucidate the potential mechanisms. METHODS ApoE-/-mice were fed a high-fat diet to establish an atherosclerotic model, then divided into normal diet(ND) group, normal diet+melatonin(ND+melatonin) group, high fat diet(HFD)group and high fat diet+melatonin(HFD+melatonin) group.After 12 weeks, HE and oil Red O staining were used to detect the formation of atherosclerosis; qRT-RCR and Western blotting were used to detect the expression of NLRP3, ASC, IL-1β, IL-18, GSDMD, NF-κB, miR-223 and MEG3 in aortic endothelium; The luciferase assay was used to detect the binding of mi R-223 to MEG3. Human aortic endothelial cells(HAECs) were pretreated with ox-LDL. After melatonin treatment, qRT-RCR was used to detect the expression of mi R-223 and MEG3. Western blotting was used to detect NLRP3, ASC, c-caspase1,p-caspase1, GSDMD expression. In addition, after overexpressing MEG3 and knocking out mi R-223, the pyroptosis of HAECs was also detected. RESULTS We found intragastric administration of melatonin for 12 weeks markedly reduced the atherosclerotic plaque in aorta.Meanwhile, melatonin also attenuated the expression of pyroptosis-related genes, including NLRP3, ASC,cleaved caspase1, NF-κB/GSDMD, GSDMD N-termini,IL-1β, and IL-18 in aortic endothelium of melatonin-treated animals. Consistent antipyroptotic effects were also observed in ox-LDL-treated human aortic endothelial cells(HAECs). We found that lnc RNA MEG3 enhanced pyroptosis in HAECs. Moreover, MEG3 acted as an endogenous sponge by sequence complementarity to suppress the function of mi R-223 and to increase NLRP3 expression and enhance endothelial cel pyroptosis. Furthermore, knockdown of mi R-223 blocked the antipyroptotic actions of melatonin in ox-LDL-treated HAECs. CONCLUSION Our results suggest that melatonin prevents endothelial cell pyroptosis via MEG3/mi R-223/NLRP3 axis in atherosclerosis, and therefore, melatonin replacement might be considered a new strategy for protecting endothelium against pyroptosis, thereby for the treatment of atherosclerosis associated with pyroptosis.     

Polydatin attenuates renal fibrosis in diabetic mice through regulating the Cx32-Nox4 signaling pathway

We previously found that polydatin could attenuate renal oxidative stress in diabetic mice and improve renal fibrosis. Recent evidence shows that NADPH oxidase 4 (Nox4)-derived reactive oxygen species (ROS) contribute to inflammatory and fibrotic processes in diabetic kidneys. In this study we investigated whether polydatin attenuated renal fibrosis by regulating Nox4 in vitro and in vivo. In high glucose-treated rat glomerular mesangial cells, polydatin significantly decreased the protein levels of Nox4 by promoting its K48-linked polyubiquitination, thus inhibited the production of ROS, and eventually decreasing the expression of fibronectin (FN) and intercellular adhesion molecule-1 (ICAM-1), the main factors that exacerbate diabetic renal fibrosis. Overexpression of Nox4 abolished the inhibitory effects of polydatin on FN and ICAM-1 expression. In addition, the expression of Connexin32 (Cx32) was significantly decreased, which was restored by polydatin treatment. Cx32 interacted with Nox4 and reduced its protein levels. Knockdown of Cx32 abolished the inhibitory effects of polydatin on the expression of FN and ICAM-1. In the kidneys of streptozocin-induced diabetic mice, administration of polydatin (100 mg·kg⁻¹·d⁻¹, ig, 6 days a week for 12 weeks) increased Cx32 expression and reduced Nox4 expression, decreased renal oxidative stress levels and the expression of fibrotic factors, eventually attenuating renal injury and fibrosis. In conclusion, polydatin promotes K48-linked polyubiquitination and degradation of Nox4 by restoring Cx32 expression, thereby decreasing renal oxidative stress levels and ultimately ameliorating the pathological progress of diabetic renal fibrosis. Thus, polydatin reduces renal oxidative stress levels and attenuates diabetic renal fibrosis through regulating the Cx32-Nox4 signaling pathway.     

Activation of endothelial cells after exposure to ambient ultrafine particles: The role of NADPH oxidase

Several studies have shown that ultrafine particles (UFPs) may pass from the lungs to the circulation because of their very small diameter, and induce lung oxidative stress with a resultant increase in lung epithelial permeability. The direct effects of UFPs on vascular endothelium remain unknown. We hypothesized that exposure to UFPs leads to endothelial cell O₂⁻ generation via NADPH oxidase and results in activation of endothelial cells. Our results showed that UFPs, at a non-toxic dose, induced reactive oxygen species (ROS) generation in mouse pulmonary microvascular endothelial cells (MPMVEC) that was inhibited by pre-treatment with the ROS scavengers or inhibitors, but not with the mitochondrial inhibitor, rotenone. UFP-induced ROS generation in MPMVEC was abolished by p67^phox siRNA transfection and UFPs did not cause ROS generation in MPMVEC isolated from gp91^phox knock-out mice. UFP-induced ROS generation in endothelial cells was also determined in vivo by using a perfused lung model with imaging. Moreover, Western blot and immunofluorescence staining results showed that MPMVEC treated with UFPs resulted in the translocation of cytosolic proteins of NADPH oxidase, p47^phox, p67^phox and rac 1, to the plasma membrane. These results demonstrate that NADPH oxidase in the pulmonary endothelium is involved in ROS generation following exposure to UFPs. To investigate the activation of endothelial cells by UFP-induced oxidative stress, we determined the activation of the mitogen-activated protein kinases (MAPKs) in MPMVEC. Our results showed that exposure of MPMVEC to UFPs caused increased phosphorylation of p38 and ERK1/2 MAPKs that was blocked by pre-treatment with DPI or p67^phox siRNA. Exposure of MPMVEC obtained from gp91^phox knock-out mice to UFPs did not cause increased phosphorylation of p38 and ERK1/2 MAPKs. These findings confirm that UFPs can cause endothelial cells to generate ROS directly via activation of NADPH oxidase. UFP-induced ROS lead to activation of MAPKs through induced phosphorylation of p38 and ERK1/2 MAPKs that may further result in endothelial dysfunction through production of cytokines such as IL-6. Our results suggest that endothelial oxidative stress may be an important mechanism for PM-induced cardiovascular effects.     

普罗布考对心脏微血管内皮细胞eNOS脱耦联与NADPH氧化应激途径的影响

目的观察普罗布考对心脏微血管内皮细胞内内皮型一氧化氮合酶（eNOS）脱耦联的作用,探讨其作用机制。方法100 mg&#8226;L－1牛血清清蛋白糖基化终末产物（BSA AGEs）与5,10,20 μmol&#8226;L－1普罗布考作用于心脏微血管内皮细胞24 h,检测四氢生物喋呤（BH4）、一氧化氮（NO）和超氧阴离子（O2 ）,免疫组织化学检测eNOS蛋白表达情况,荧光染色检测活性氧簇（ROS）,Western blot检测p47phox蛋白。结果随着普罗布考浓度增加,NO生成增加,O2 生成减少,eNOS表达减少,BH4含量增加,ROS表达降低,p47phox表达减少（P＜0.01或P＜0.05）。结论普罗布考能抑制AGEs诱导的心脏微血管内皮细胞eNOS脱耦联,其机制可能与抑制NADPH氧化应激有关。     

Nrf2/HO-1 pathway activation by manganese is associated with reactive oxygen species and ubiquitin-proteasome pathway, not MAPKs signaling

Manganese has been known to induce neurological disorders similar to Parkinson's disease. One of the features of manganese-induced neurotoxicity is oxidative stress. Accumulating data implicate NF-E2-related factor 2 (Nrf2) as a key regulator in the adaptive survival response to oxidative stress. Recent studies suggest that the activation of Nrf2 is induced by manganese in PC12 cells. In the present study, we investigated possible links between reactive oxygen species (ROS), proteasome or mitogen-activated protein kinase (MAPK) signaling and Nrf2/HO-1 activation in manganese-treated PC12 cells. After MnCl(2) treatment, there was an increase in nuclear localization and subsequent binding of Nrf2 to the antioxidant-responsive element (ARE) and upregulation of heme oxygenase-1 (HO-1) protein in PC12 cells. Pretreatment with N-acetyl cysteine, a scavenger of reactive oxygen species, suppressed MnCl(2) -induced Nrf2 activation, increase in Nrf2-ARE binding and subsequent upregulation of HO-1 expression. However, pretreatment with lactacystin, an inhibitor of proteasome activity, enhanced MnCl(2) -induced Nrf2 activation, increase in Nrf2-ARE binding and subsequent upregulation of HO-1 expression. Pretreatment of cells with a pharmacological inhibitor of MAPK (ERK inhibitor PD 98059, P38 inhibitor SB203580 or JNK inhibitor SP600125) did not affect the MnCl(2) -induced Nrf2 activation, increase in Nrf2-ARE binding or subsequent upregulation of HO-1 expression. These results suggest that Nrf2/HO-1 activation by Mn in PC12 cells is associated with ROS and the ubiquitin-proteasome pathway, not MAPK signaling.     

Calycopterin promotes survival and outgrowth of neuron-like PC12 cells by attenuation of oxidative- and ER-stress-induced apoptosis along with inflammatory response

There is mounting evidence implicating the role of oxidative stress induced by reactive oxygen species (ROS) in neurodegenerative disease, including Alzheimer's disease. Herein we investigated the neuroprotective potential of a natural flavonoid, calycopterin, against H(2)O(2)-induced cell death in differentiated PC12 cells. We pretreated PC12 cells with 25, 50, and 100 μM calycopterin followed by the addition of H(2)O(2) as an oxidative stress agent. We measured cell viability by the MTT test and found that 50 μM is the best protective concentration of calycopterin. Moreover, we measured six different parameters of neurite outgrowth. Interestingly, we found that calycopterin not only protects PC12 cells against H(2)O(2)-induced apoptosis but also defends against the destructive effect of oxidative stress on the criteria of neural differentiation. Calycopterin decreased ER stress-associated proteins including calpain and caspase-12, and suppressed ERK, JNK, and p38 MAPK phosphorylation. Moreover, calycopterin inhibited H(2)O(2)-induced nuclear translocation of nuclear factor-κB, a known regulator of a host of genes involved in specific stress and inflammatory responses. This observation was perfectly in agreement with the decrease of COX-2 and TNF-α levels. Calycopterin reduced intracellular ROS levels and increased catalase activity. The protective effect of this compound could represent a promising approach for the treatment of neurodegenerative diseases.     

GSDMD介导的细胞焦亡研究进展

细胞焦亡是一种新发现的细胞程序性死亡方式,它的形态学特征,分子机制与其他细胞死亡方式不同。细胞焦亡作为近些年来研究的热门之一,有不少研究者发现它与多种疾病之间密切相关。目前研究发现关键蛋白之一gasdermin D（GSDMD）发挥重要作用,对其与细胞焦亡之间的关系,分子机制进行研究,有助于了解细胞焦亡与疾病之间的联系,为疾病的治疗提供新的思路和靶点。     

3,4,5,6-Tetrahydroxyxanthone preserves intercellular communication by reduction of the endogenous nitric oxide synthase inhibitor level

To observe the direct effects of 3,4,5,6-tetrahydroxyxanthone on connexin43 (Cx43) expression in cultured endothelial cells, cells were treated with lysophosphatidylcholine (LPC, 10?mg/l) for 24?h in the presence or absence of different concentrations of 3,4,5,6-tetrahydroxyxanthone (1, 3, or 10?μmol?l(-?1)). The reactive oxygen species (ROS) production, cell viability, asymmetric dimethylarginine (ADMA) levels, and Cx43 expression were detected. 3,4,5,6-Tetrahydroxyxanthone significantly inhibited the increase in ROS production and ADMA level, increased cell viability and up-regulated Cx43 mRNA and protein expression induced by LPC. 3,4,5,6-Tetrahydroxyxanthone has protective effect in LPC-induced atherosclerotic lesions, which is at least partly related to the reduction of ADMA level and downregulation of Cx43 expression.