Pitavastatin attenuates AGEs-induced mitophagy via inhibition of ROS generation in the mitochondria of cardiomyocytes

This study aimed to investigate whether pitavastatin protected against injury induced by advanced glycation end products products (AGEs) in neonatal rat cardiomyocytes, and to examine the underlying mechanisms. Cardiomyocytes of neonatal rats were incubated for 48 hours with AGEs (100 mg/mL), receptor for advanced glycation end products (RAGE), antibody (1 mg/mL) and pitavastatin (600 ng/mL). The levels of p62 and beclin1 were determined by Western blotting. Mitochondrial membrane potential (DYm) and the generation of reactive oxygen species (ROS) were measured through the JC-1 and DCFH-DA. In the AGEs group, the expression of beclin1 was remarkably increased compared to the control group, while the expression of p62 was significantly decreased. AGEs also markedly decreased DYm and significantly increased ROS compared with the control group. After treatment with RAGE antibody or pitavastatin, the level of beclin1 was markedly decreased compared with the AGEs group, but the level of p62 was remarkably increased. In the AGEs + RAGE antibody group and AGEs + pitavastatin group, DYm was significantly increased and ROS was remarkably decreased compared with the AGEs group. In conclusion, AGEs-RAGE may induce autophagy of cardiomyocytes by generation of ROS and pitavastatin could protect against AGEs-induced injury against cardiomyocytes.     

自噬在晚期糖基化终产物诱导的内皮细胞凋亡中的作用

目的: 研究晚期糖基化终产物(AGEs)对人脐静脉内皮细胞(HUVECs)自噬水平的影响并探讨自噬在AGEs诱导的内皮细胞凋亡中的作用。方法: 用AGEs处理HUVECs,相同条件牛血清白蛋白处理为对照组,Western blotting检测相应蛋白表达的变化,电镜观察细胞自噬体的出现,流式细胞术检测细胞凋亡,MTT比色法测定细胞活性。结果: AGEs处理HUVECs后,自噬相关蛋白LC3-Ⅱ的表达显著上调并呈时间和浓度依赖性,电镜观察到细胞胞浆内自噬体数量增加;与对照组比较,AGEs处理组内皮细胞凋亡率增加,活性下降,自噬抑制剂3-甲基腺嘌呤预处理的AGEs组细胞活性较AGEs组进一步下降,凋亡率继续增加。AGEs处理HUVECs后,蛋白激酶B(Akt)和哺乳动物雷帕霉素靶蛋白(mTOR)的磷酸化水平也明显下调, Akt激活剂胰岛素样生长因子1预处理后,Akt的磷酸化水平增加,自噬相关蛋白LC3-Ⅱ的增高表达被抑制。结论: AGEs通过PI3K/Akt/mTOR介导的信号通路诱导HUVECs自噬水平升高。自噬在AGEs诱导的内皮细胞凋亡中对细胞起保护作用。     

糖尿病大鼠血管糖基化终产物含量与其受体的ICAM—1表达的关系

探讨糖尿病大鼠血管组织糖基化终产物（AGEs)含量与其受体（RAGE）和细胞间粘附因子－1（ICAM－1）表达的关系。复制糖尿病大鼠模型,采用荧光法、RT－PCR及原位杂交方法检测主动脉及心肌组织的AGEs含量以及RAGE和ICAM－1基因的表达。发现糖尿病大鼠主动脉和心肌组织AGEs含量升高（P＜0．01）;RAGE和ICAM－1基因表达增强（P＜0．05－0．05）;AGEs含量与RAGE及ICAM－1呈明显正相关（P＜0．01）;氨基胍治疗可缓解上述指标的变化。提示 AGEs可诱导RAGE和ICAM－1的表达。推测AGEs-RAGE相互作用是引起糖尿病血管内皮细胞功能紊乱和损伤的关键环节。     

瑞舒伐他汀通过抑制晚期糖基化终末产物受体改善晚期内皮祖细胞再内皮化功能

 目的: 研究C反应蛋白(CRP)对晚期内皮祖细胞的晚期糖基化终产物受体(RAGE)表达的影响,并探讨瑞舒伐他汀是否改善CRP诱导的晚期内皮祖细胞再内皮化功能。方法: Western blot检测RAGE蛋白表达情况,MTT检测细胞活力、Transwell小室检测迁移能力及黏附能力来观察瑞舒伐他汀对于CRP诱导的晚期内皮祖细胞再内皮化功能的影响。结果: 随着CRP刺激浓度增加,RAGE蛋白表达量逐渐增加;而瑞舒伐他汀预孵育后,RAGE表达量逐渐下降。瑞舒伐他汀对于CRP诱导后的晚期内皮祖细胞的细胞活性没有显著改变;而迁移能力和粘附能力均随着瑞舒伐他汀浓度逐渐增加而增加,其中10^-6 mol/L瑞舒伐他汀组与CRP对照组比较均显著增强(P<0.01)。结论: CRP上调晚期内皮祖细胞RAGE的表达,瑞舒伐他汀可通过抑制RAGE表达增强CRP诱导的晚期内皮祖细胞的迁移和粘附能力,从而改善其再内皮化功能。     

糖基化终产物对人单核细胞源树突状细胞糖基化终产物受体表达的研究

目的：探讨糖基化终产物 (AGEs）)对人单核细胞源树突状细胞（MDCs）糖基化终产物受体（RAGE） 表达的影响。 方法： 用免疫磁珠分离人外周血CD14+单核细胞，经含rhGM-CSF（100 μg/L）和rhIL-4（50 μg/L）的RPMI-1640培养，使其分化为MDCs，采用RT-PCR和Western blotting法，观察糖基化-白蛋白（AGE-BSA）对MDCs RAGE mRNA和蛋白表达的影响，同时检测培养液上清中IFN-γ和IL-12的浓度。 结果： AGE-BSA诱导DCs RAGE mRNA和蛋白的表达（P＜0.05），高于空白对照组，并且明显促进了DCs IFN-γ和IL-12的分泌（P＜0.05）。BSA干预组与空白对照组相比差异无显著（P＞0.05）。 结论： AGEs能够上调DCs RAGE的表达，并且促进了DCs IFN-γ和IL-12的分泌，这可能是糖尿病通过DCs促进动脉粥样硬化发生的重要机制之一。     

Kinetics of plasma SPB and RAGE during mechanical ventilation in patients undergoing major vascular surgery

Receptor-of-Advanced-Glycation-End-products (RAGE) and Surfactant-Protein-type-B (SPB) are reported as lung injury markers. Unlike SPB, RAGE is secreted by several tissues, so that RAGE specificity as lung injury marker is questionable. We measured SPB and RAGE in 19 patients undergoing major vascular abdominal surgery. SPB and RAGE were measured before mechanical ventilation (T0), at 1st (T1), 2nd (T2) and, when present, 3rd (T3) hour of mechanical ventilation, and 1h after extubation (T(POST)). Last data during mechanical ventilation, either T2 or T3, are reported as T(END). SPB and RAGE values were normalized for total protein (SPB(N) and RAGE(N)). SPB(N) and RAGE(N) increments from T0 to T(END) were 56.2 [39.1] ng/mg (mean [75-25 percentile]) and 10.6[7.1] pg/mg, respectively. SPB values increased progressively during mechanical ventilation, whereas RAGE values increased at T(1) but not thereafter. SPB(N) increase (T(END)-T0), but not RAGE(N), was related to ΔPaO(2)/FiO2 changes during mechanical ventilation (r=0.575, p=0.01). Plasma RAGE(N) and SPB(N) kinetics in patients undergoing major vascular surgery are different.     

抑制RAGE表达的siRNA重组腺病毒载体的构建及鉴定

目的 构建特异性针对细胞膜上晚期糖基化终末产物受体(RAGE)的小干扰RNA(siRNA)腺病毒载体,鉴定其对大鼠胰岛β细胞系INS-1细胞RAGE表达的影响.方法 设计并合成针对大鼠RAGE基因的siRNA的靶DNA序列,克隆于穿梭载体pAdTrack中,与腺病毒骨架质粒pAdeasy-1在BJ5183细菌中进行同源重组,脂质体法转染至QBI293A细胞中包装,获得RAGE-siRNA的重组腺病毒,荧光显微镜观察RAGE-siRNA感染INS-1细胞后绿色荧光蛋白(GFP)的表达,Western印迹检测RAGE的蛋白表达.结果 成功制备RAGE-siRNA重组腺病毒,在INS-1细胞中RAGE-siRNA感染效率达到90 %以上,并能够抑制INS-1细胞RAGE的表达.结论 成功构建了携带RAGE的siRNA重组腺病毒载体,能有效沉默INS-1细胞中RAGE的表达.     

糖基化终产物通过其受体诱导人肾小球系膜细胞表达CTGF和FN

目的： 探讨体外培养条件下糖基化终产物（AGEs）对人肾小球系膜细胞(HRMCs）中结缔组织生长因子（CTGF）及纤维连接蛋白（FN）基因表达的影响及其可能的作用机制。方法: 将HRMCs与不同浓度的糖化牛血清白蛋白（AGE-BSA）和牛血清白蛋白（BSA）共同培养,或与同一质量浓度的AGE-BSA和BSA共同培养不同时间,以中和性抗RAGE抗体封闭细胞膜上糖基化终末产物受体（RAGE）;采用免疫印迹法（Western blotting）观察AGEs对HRMCs中RAGE表达的影响,半定量逆转录-聚合酶链反应（RT-PCR）法检测CTGF、FN mRNA的表达。结果: 在HRMCs中存在少量RAGE的表达,AGE-BSA能够诱导HRMCs中RAGE的表达增加,并以时间和剂量依赖方式促进HRMCs中CTGF和FN的表达上调;CTGF、FN的表达水平在加入不同浓度（50、100、200、400 mg/L）的AGE-BSA 作用48 h后以及加入质量浓度为200 mg/L的 AGE-BSA 作用不同时间（12、24、48、72h）后,较相应质量浓度或时间的BSA组和空白对照组均明显升高（P＜0.05）;抗RAGE抗体干预后能够部分抑制AGE-BSA诱导CTGF及FN的表达,而人IgG没有这种作用。结论: AGEs可能通过RAGE诱导CTGF及FN的表达上调,是糖尿病肾病肾脏纤维化的可能机制。     

Protective effect of rapamycin against acrylamide-induced hepatotoxicity: The associations between autophagy,apoptosis, and necroptosis

Acrylamide (ACRL) was demonstrated to induce hepatotoxicity and programmed cell death (PCD). Rapamycin (RAPA)-induced autophagy had been reported to limit the progression of hepatocellular injury in experimental models. This research was designed to study two death pathways involved in ACRL-induced hepatotoxicity and the modulating effect of RAPA on the resulting hepatic injury. Thirty-six adult male rats were divided into three groups: control group, ACRL-treated group (20 mg kg/day), and the last group co-treated with ACRL plus RAPA (0.5 mg kg/day). Drugs were administered for 21 days via oral gavage. Blood samples were collected to assess alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Livers were dissected; parts were used for detection of superoxide dismutase (SOD) and malondialdehyde (MDA) tissue levels. Other parts were processed for hematoxylin and eosin, Masson's trichrome staining, immunostaining for microtubule-associated proteins 1A/1B light chain 3B (LC3), ubiquitin-binding protein (p62), caspase-3, and receptor-interacting protein kinase 1 (RIPK1). ACRL induced a significant elevation in ALT, AST, MDA levels, and reduction in the SOD level. ACRL also induced hepatocellular injury, fibrosis, and defective autophagy indicated by elevation of LC3 and p62 and increased p62/LC3 ratio. Moreover, it increased the apoptotic (caspase-3) and necroptotic (RIPK1) markers expression. RAPA significantly reduced liver enzymes, oxidative stress, fibrosis, and improved liver histology. Moreover, RAPA decreased p62/LC3 ratio indicated enhanced autophagy, and significantly reduced caspase-3 and RIPK1 expression. In conclusion, RAPA maintained autophagic activity which may save the hepatocytes from PCD and enhance cell viability.     

糖基化终产物和高糖对小牛主动脉血管细胞的损伤作用

目的研究糖基化终产物（AGEs）和高浓度葡萄糖对血管细胞的损伤及对其糖基化终产物受体（RAGE）表达的影响。方法分别用10g/L糖基化终产物、10mol／L葡萄糖和两者的混合作用于牛主动脉血管细胞，利用生化方法测定细胞乳酸脱氢酶（IDH）、还原型谷胱甘肽（GSH）和NO2^-／NO3^-的含量，用MTT法测定细胞的活性。用CELL-ELISA和RT-PCR检测细胞RAGE的表达。结果与正常组（C）相比，高糖组（G）、AGEs组（A）和联合损伤组（G＋A）对主动脉内皮细胞的生长有明显的抑制作用（P〈0．01）和对平滑肌细胞的生长有明显的促进作用，主动脉血管细胞LDH的泄漏量明显增高，GSH和NO2^-／NO3^-的含量明显减少（P〈0．01）；且在的作用最强。同时，联合损伤组血管细胞的RAGE表达水平明显高于AGEs组和高糖组。结论AGEs比高浓度葡萄糖更具损伤血管细胞的作用，且AGEs与高糖联合作用对细胞的损伤最为明显，这种联合损伤的过程也是通过RAGE介导的。联合损伤组     

程序化细胞死亡因子5对缺氧/复氧诱导的心肌细胞凋亡和自噬的影响及机制

目的:探讨程序化细胞死亡因子5(PDCD5)对缺氧/复氧(H/R)诱导的心肌细胞凋亡和自噬的影响及其作用机制。方法:以H9c2心肌细胞系为研究对象,建立H/R损伤模型,采用RNA干扰方法抑制PDCD5的表达,MTT法检测心肌细胞的存活率,TUNEL显色法检测细胞凋亡率,RT-qPCR和Western blot法分别检测mRNA和蛋白的表达水平。结果:H/R损伤的H9c2心肌细胞中,PDCD5表达水平升高,同时细胞的存活率降低,细胞凋亡率和自噬水平增加,而PDCD5沉默能够增加细胞存活率,同时减少细胞凋亡率,促进Bax表达且抑制抑Bcl-2、LC3-Ⅱ/LC3-Ⅰ及自噬相关蛋白beclin-1的表达。此外,沉默PDCD5可通过降低p-P65的蛋白水平抑制NF-κB通路。结论:沉默PDCD5通过阻断NF-κB信号通路而抑制H/R损伤诱导的心肌细胞凋亡和自噬,从而保护心肌细胞。     

Advanced glycation end-products and receptor for advanced glycation end-products expression in patients with idiopathic pulmonary fibrosis and NSIP

Advanced glycation end products (AGEs) are associated with the pathogenesis of various diseases. AGEs induce excess accumulation of extracellular matrix and expression of profibrotic cytokines. In addition, studies on receptor for advanced glycation end products (RAGE) have shown that the ligand-RAGE interaction activates several intracellular signaling cascades associated with several fibrotic diseases. We investigated the expression of AGEs and RAGE in samples from patients with idiopathic pulmonary fibrosis (IPF) and non-specific interstitial pneumonia (NSIP). Lung tissues and plasma samples from patients with IPF (n=10), NSIP (n=10), and control subjects (n=10) were obtained. Expression of AGEs and RAGE was determined by immunofluorescence assay of lung tissue. Circulating AGEs were measured by Western blot and enzyme-linked immunosorbent assay. Lungs with IPF showed strong expression for both AGEs and RAGE compared to that in NSIP and controls. However, no difference in AGE or RAGE expression was observed in lungs with NSIP compared to that in the controls. Levels of circulating AGEs also increased significantly in lungs of patients with IPF compared to those with NSIP and normal control. Increased AGE-RAGE interaction may play an important role in the pathogenesis of IPF.     

脂联素抑制β1-肾上腺素受体自身抗体诱导的大鼠H9c2心肌细胞自噬流下降

目的:观察脂联素抑制β1-肾上腺素受体(β1-AR)自身抗体(β1-AA)诱导的大鼠心肌细胞自噬流下降的作用及机制。方法:SD大鼠随机分为免疫组和对照(control)组,每组6只;H9c2大鼠心肌细胞分为control组、β1-AA组、β1-AA+脂联素组、脂联素组、β1-AA+脂联素+Compound C组和β1-AA+Compound C组。合成β1-AR细胞外第2环(β1-AR-ECII)抗原肽段,主动免疫SD大鼠并采用亲和层析法纯化大鼠血清中β1-AA;CCK-8法检测H9c2心肌细胞活力;real-time PCR检测心肌细胞LC3B和beclin-1的m RNA水平;Western blot检测心肌细胞LC3-II、P62、AMP活化蛋白激酶(AMPK)和磷酸化AMPK(p-AMPK)的蛋白水平。结果:与control组相比,10μg/L脂联素预处理可显著抑制β1-AA诱导的心肌细胞活力下降(P<0.05);脂联素预处理可显著逆转β1-AA诱导的心肌细胞LC3B和beclin-1 m RNA水平下降、LC3-II蛋白表达水平下降及P62蛋白的累积(P<0.05);脂联素可逆转β1-AA诱导的心肌细胞AMPK磷酸化水平下降(P<0.05)。加入AMPK抑制剂Compound C预处理,脂联素则不能逆转β1-AA诱导的心肌细胞LC3B和beclin-1 m RNA及LC3-II蛋白水平降低(P<0.05),但仍可减少P62蛋白累积(P<0.05)。结论:脂联素抑制β1-AA诱导的H9c2大鼠心肌细胞自噬流降低,其机制部分依赖AMPK途径。     

Differential expression of receptors for advanced glycation end-products in peritoneal mesothelial cells exposed to glucose degradation products

Autoclaving peritoneal dialysate fluid (PDF) degrades glucose into glucose degradation products (GDPs) that impair peritoneal mesothelial cell functions. While glycation processes leading to formation of advanced glycation end-products (AGE) were viewed commonly as being mediated by glucose present in the PDF, recent evidence indicates that certain GDPs are even more powerful inducers of AGE formation than glucose per se. In the present study, we examined the expression and modulation of AGE receptors on human peritoneal mesothelial cells (HPMC) cultured with GDPs, conventional PDF or PDF with low GDP content. HPMC cultured with GDPs differentially modulated AGE receptors (including RAGE, AGE-R1, AGE-R2 and AGE-R3) expression in a dose-dependent manner. At subtoxic concentrations, GDPs increased RAGE mRNA expression in HPMC. 2-furaldehyde (FurA), methylglyoxal (M-Glx) and 3,4-dideoxy-glucosone-3-Ene (3,4-DGE) increased the expression of AGE-R1 and RAGE, the receptors that are associated with toxic effects. These three GDPs up-regulated the AGE synthesis by cultured HPMC. In parallel, these GDPs also increased the expression of vascular endothelial growth factor (VEGF) in HPMC. PDF with lower GDP content exerted less cytotoxic effect than traditional heat-sterilized PDF. Both PDF preparations up-regulated the protein expression of RAGE and VEGF. However, the up-regulation of VEGF in HPMC following 24-h culture with conventional PDF was higher than values from HPMC cultured with PDF containing low GDP. We have demonstrated, for the first time, that in addition to RAGE, other AGE receptors including AGE-R1, AGE-R2 and AGE-R3 are expressed on HPMC. Different GDPs exert differential regulation on the expression of these receptors on HPMC. The interactions between GDPs and AGE receptors may bear biological relevance to the intraperitoneal homeostasis and membrane integrity.     

DENV-2 诱导HUVECs 自噬和影响细胞活力的研究

目的:通过利用登革域型病毒(DENV-2)感染原代人脐静脉内皮细胞(HUVECs)后,研究病毒诱导HUVECs 产生自噬和对细胞活力的影响。方法:利用DENV-2 NGC 株感染HUVECs,Real-time PCR 检测HUVECs 中DENV-2 NS1 基因部分系列的表达,给予自噬诱导剂雷帕霉素(RAPA)和自噬抑制剂氯喹(CQ)预处理观察细胞自噬通量变化,激光共聚焦显微镜观察自噬体形成;CCK-8 检测细胞活力;Western blot 检测自噬通量标志性蛋白LC3、P62 的蛋白表达量。结果:DENV-2 感染HUVECs 组病毒NS1 基因在各时间点均有表达;被感染的HUVECs 在24 h 时细胞活力下降不明显,36、48 h 细胞活力分别下降至未处理组82.46%和78.47%,差异具有显著统计学意义(P<0.05);HUVECs 被DENV-2 感染后,LC3-Ⅱ蛋白量表达明显增高,自噬底物P62 表达明显降低,36、48 h 时间点相较未处理组具有统计学意义(P<0.05),与RAPA 处理组结果相似(P>0.05)。CQ 处理组LC3-Ⅱ及P62 蛋白量表达均明显升高,36、48 h 时间点相较未处理组具有显著性差异(P<0.05)。HUVECs被DENV-2 感染36 h,激光共聚焦显微镜观察到LC3-Ⅱ表达明显高于未处理组,自噬诱导剂RAPA 处理HUVECs 后,LC3-Ⅱ表达明显增加,自噬强度更加明显。DENV-2 与CQ 联合处理组相较DENV 单独处理组,36 h 细胞活力下降了13.61%,差异具有显著统计学意义(P<0.05)。结论:DENV-2 感染可抑制HUVECs 的生长;而DENV-2 诱导HUVECs 产生的自噬却有利于HUVECs 的存活。     

Akt激酶抑制剂MK-2206诱导U2OS人骨肉瘤细胞凋亡与自噬

 目的：研究Akt抑制剂MK-2206对U2OS细胞凋亡和自噬的影响。方法：采用MTT法检测MK-2206对U2OS细胞活力的影响,DNA片段末端标记试剂盒检测细胞凋亡的变化,免疫印迹法检测细胞内蛋白的表达,用LC3-II的表达量用来确定细胞的自噬水平。结果：MK-2206剂量依赖性地降低了U2OS细胞的活力;MK-2206能够促进caspase-9、caspase-3和PARP的活化切割而诱导U2OS细胞发生凋亡;MK-2206给药后可促进细胞内LC3-II的表达,氯喹阻断自噬后明显增强了MK-2206对U2OS细胞活力的抑制作用。结论：Akt 抑制剂MK-2206能够诱导U2OS细胞发生凋亡和自噬;抑制自噬可促进MK-2206对U2OS细胞的毒性。     

氧化低密度脂蛋白通过CD36介导的氧化应激诱导巨噬细胞自噬

目的:研究氧化低密度脂蛋白(oxidized low-density lipoprotein,ox-LDL)对巨噬细胞自噬的诱导作用,并探讨可能的分子机制。方法:体外培养RAW264.7巨噬细胞,给予抗CD36单克隆抗体(2 mg/L)、二亚苯基碘鎓(diphenyleneiodonium,DPI;5μmol/L)、3-甲基腺嘌呤(3-methyladenine,3-MA;3 mmol/L)或雷帕霉素(1μmol/L)预处理1 h,再加入ox-LDL(100 mg/L)继续培养12 h。采用MTT法检测细胞活力,采用相应试剂盒测定培养液乳酸脱氢酶(lactic dehydrogenase,LDH)、细胞内烟酰胺腺嘌呤二核苷酸磷酸(nicotinamide adenine dinucleotide phosphate,NADPH)氧化酶、超氧化物歧化酶(superoxide dismutase,SOD)活性以及活性氧簇(reactive oxygen species,ROS)和丙二醛(malondialdehyde,MDA)水平,以评价细胞膜完整性和氧化应激反应。采用免疫印迹技术检测自噬标志分子beclin-1和微管相关蛋白1轻链3-II(microtubule-associated protein 1 light chain 3-II,LC3-II)表达变化。结果:ox-LDL诱导巨噬细胞自噬反应,表现为beclin-1和LC3-II上调;与自噬抑制剂3-MA相似,抗CD36单抗可显著抑制ox-LDL所诱导的LC3-II和beclin-1表达。抗CD36单抗明显抑制ox-LDL所诱导的氧化应激,包括抑制NADPH氧化酶活性和ROS、MDA水平以及升高SOD活性,其作用与NADPH氧化酶抑制剂DPI相似。另外,DPI显著抑制ox-LDL所诱导的beclin-1和LC3-II表达,且ox-LDL所诱导的细胞活力降低和LDH漏出可被3-MA促进并可被自噬诱导剂雷帕霉素拮抗。结论:ox-LDL可诱导巨噬细胞自噬,其机制可能与CD36介导ox-LDL摄取进而触发的氧化应激有关,且一定程度的自噬可减轻ox-LDL所诱导的巨噬细胞损伤。     

天麻素抑制脂多糖诱导的人脐静脉内皮细胞的自噬

目的 探讨天麻素(Gas)在脂多糖 (LPS) 诱导的人脐静脉内皮细胞 ( HUVECs) 自噬中的作用。方法 用不同浓度的Gas(5、10、20、50μmol/L) 预处理 HUVECs 1h,再加入1mg/L LPS共培养 12 h后,分别提取细胞总蛋白及mRNA,采用 Western blotting 及 RT-PCR 检测 Beclin-1、ATG5 及 LC3的表达变化;采用丹酰尸胺( MDC) 染色检测细胞中自噬小体(autophagosome)的表达变化;采用MTT检测 HUVECs 生存率的变化。 结果 LPS 诱导 HUVECs 产生自噬;Gas 预处理后自噬水平明显降低且呈剂量依赖性;与此同时细胞的生存率明显增加。 结论 LPS诱导 HUVECs 产生自噬;Gas 通过抑制由LPS 诱导产生的自噬,提高 HUVECs 的生存率。     

梓醇抑制AGEs诱导的EA.hy926细胞炎症反应及RAGE表达

目的:研究梓醇对晚期糖基化终产物(AGEs)诱导的EA.hy926内皮细胞炎症反应的抑制作用并探讨其可能机制。方法:将常规培养的EA.hy926细胞随机分为对照组、梓醇对照组、AGEs组以及梓醇高剂量(0.5 mmol/L)、中剂量(0.25 mmol/L)和低剂量(0.05 mmol/L)保护组。激光共聚焦显微镜观察细胞内活性氧簇(ROS)的生成;RT-PCR和Western blot检测细胞中单核细胞趋化蛋白1(MCP-1)、肿瘤坏死因子α(TNF-α)、血管细胞黏附分子1(VCAM-1)及晚期糖基化终产物受体(RAGE)的mRNA及蛋白的表达。结果:梓醇保护组ROS生成均明显减少,MCP-1、TNF-α和VCAM-1的mRNA及蛋白表达均显著降低,RAGE蛋白表达明显受抑制,且呈剂量依赖性(P0.05)。结论:梓醇能够有效抑制AGEs诱导的EA.hy926细胞内氧化应激,减轻炎症反应,其机制可能与其降低RAGE表达有关。     

Curcumin induces permanent growth arrest of human colon cancer cells: link between senescence and autophagy

Curcumin, a natural polyphenol derived from the rhizome of Curcuma longa, is a potent anticancer agent, which restricts tumor cell growth both in vitro and in vivo. Thus far curcumin was shown to induce death of cancer cells. This study reports the induction of cellular senescence of human colon cancer cells HCT116 upon curcumin treatment. The SA-β-galactosidase activation was observed both in p53+/+ and p53−/− cells, however the latter ones were less sensitive to the prosenescent activity of curcumin. Upregulation of p53 and p21 proteins was observed in p53+/+ HCT116, while p53-independent induction of p21 was noticed in p53−/− HCT116. Moreover, the senescence of HCT116 cells was accompanied by autophagy, that was confirmed by electron microscopy observations of autophagosomes in the curcumin-treated cells as well as LC3-II expression, punctue staining of LC3 and increased content of acidic vacuoles. Inhibition of autophagy, due to the diminished expression of ATG5 by RNAi decreased the number of senescent cells induced by curcumin, but did not lead to increased cell death. Altogether, we demonstrated a new antitumor activity of curcumin leading to cancer cell senescence and revealed the presence of a functional link between senescence and autophagy in curcumin-treated cells.