OBJECTIVE To investigate icariside(ICS)Ⅱ protects against PC12 cel damage induced by oxygen-glucose deprivation and reoxygenation and explore its mechanism.METHODS The oxidative stress injury model was induced by oxy...OBJECTIVE To investigate icariside(ICS)Ⅱ protects against PC12 cel damage induced by oxygen-glucose deprivation and reoxygenation and explore its mechanism.METHODS The oxidative stress injury model was induced by oxygen-glucose deprivation/reoxygenation(OGD/R) 2 h/24 h in PC12 cells.N-acetyl-lcysteine(NAC),a classical anti-oxidant,was used as positive control.Pharmacodynamic experimental study groups as follows:control,control+ICS Ⅱ50 μmol·L^(-1),OGD/R,OGD/R+ICSⅡ 12.5 μmol·L^(-1),OGD/R + ICS Ⅱ 25 μmol·L^(-1),OGD/R + ICS Ⅱ50 μmol·L^(-1),and OGD/R+NAC 100 μmol·L^(-1) groups.Cell viability and lactate dehydrogenase(LDH) leakage rate were measured by MTT assay and LDH ELISA kit,respectively.Moreover,reactive oxygen species(ROS) ELISA kit was used for detection of intracellular ROS generation,Mito-SOX fluorescence staining was used for detecting production of ROS in mitochondria and mitochondrial membrane potential(MMP)was detected by rhodamine 123 dye.In addition,PC12 cells apoptosis was detected by one-step TUNEL assay.Furthermore,the expressions of nuclear factor erythroid 2-related factors(Nrf2),Keap1,HO^(-1),NQO^(-1),silent information regulator 3(SIRT3),IDH2,Bax,Bcl-2 and caspase 3 were detected by Western blotting analysis.RESULTS The results of MTT and LDH assay showed that OGD/R reduced the cell viability and improved LDH release compared with the control or ICSⅡ 50 μmol·L^(-1) alone(P<0.01).Meanwhile,OGD/R not only increased intracellular and mitochondrial ROS generation,but also elevated the fluorescence intensity of TUNEL staining,at the same time,the MMP was declined when challenged by OGD/R.Furthermore,the Western blotting results showed that OGD/R induced the increase in the expression of cytoplasm-Nrf2,Keap1,Bax and cleaved-caspase 3 level,while the decrease in the expression of nucleus-Nrf2,HO^(-1),NQO^(-1),SIRT3,IDH2 and Bcl-2(P<0.05).However,ICS Ⅱ significantly increased the viability of PC12 cells and reduced LDH leakage(P<0.01).Notably,ICS Ⅱ also suppressed ROS generation both in the intracellular and mitochondria,as well as restored MMP.It was also worthy to note that ICS Ⅱ decreased the expressions of cytoplasmNrf2,Keap1,Bax and the level of cleaved-caspase3,whereas,it increased the expressions of nucleus-Nrf2,HO^(-1),NQO^(-1),SIRT3,IDH2 and Bcl-2(P<0.05).CONCLUSION ICSⅡ reduced OGD/Rinduced oxidative damage in PC12 cells under the laboratory conditions,and its underlying mechanism may be related to the regulation of Nrf2/SIRT3 signaling pathway.展开更多
目的探讨沉默信息调节因子2相关酶2(silent information regulator 2 related enzyme 2,SIRT2)基因沉默对肝癌细胞增殖的影响及分子机制。方法利用慢病毒介导的shRNA干扰技术,靶向沉默SIRT2基因的表达;Western blot检测SIRT2基因沉默效...目的探讨沉默信息调节因子2相关酶2(silent information regulator 2 related enzyme 2,SIRT2)基因沉默对肝癌细胞增殖的影响及分子机制。方法利用慢病毒介导的shRNA干扰技术,靶向沉默SIRT2基因的表达;Western blot检测SIRT2基因沉默效果及SIRT2沉默后β-catenin蛋白的表达变化;流式细胞计数检测SIRT2基因沉默后肝癌细胞周期的变化,CCK-8法检测SIRT2基因沉默对肝癌细胞增殖的影响,台盼蓝计数检测SIRT2基因沉默及过表达β-catenin后,SIRT2基因沉默对肝癌细胞增殖的影响;BrdU实验检测SIRT2基因沉默对肝癌细胞DNA合成的影响;平板集落实验检测SIRT2沉默对肝癌细胞克隆形成能力的影响。结果 SIRT2 shRNA靶向沉默显著抑制肝癌细胞SIRT2的表达水平,shRNA沉默组肝癌细胞PLC-5的增殖能力较对照组分别下降48.3%(shSIRT2-1)、55.6%(shSIRT2-2)(P<0.01);SIRT2基因沉默后,肝癌细胞出现G1期阻滞,β-catenin蛋白表达水平下降;过表达β-catenin后SIRT2基因沉默组较对照组肝癌细胞增殖分别升高了89%(shSIRT2-1)、75%(shSIRT2-2)(P<0.01)。结论 SIRT2沉默可能通过调节β-catenin信号通路来影响肝癌细胞增殖。展开更多
Sirtuin家族是酵母沉默信息调节因子(silent information regulator factor)在哺乳动物中的同源物,属于Ⅲ类组蛋白去乙酰化酶。沉默信息调节因子2相关酶1(silent information regulator factor 2-related enzyme 1,SIRT1)是Sirtuin家族...Sirtuin家族是酵母沉默信息调节因子(silent information regulator factor)在哺乳动物中的同源物,属于Ⅲ类组蛋白去乙酰化酶。沉默信息调节因子2相关酶1(silent information regulator factor 2-related enzyme 1,SIRT1)是Sirtuin家族目前研究最为充分的成员之一。主要分布于细胞核及细胞质,通过行使其NAD+依赖的去乙酰化活性,参与调节DNA损伤修复、基因转录、能量代谢、应激及凋亡等细胞生理过程。细胞凋亡是在精确的内在遗传调控下发生的一种程序性死亡,旨在维持机体内环境稳态。异常的细胞凋亡参与多种疾病的发生,例如肿瘤、神经退行性病变、自身免疫病和缺血性疾病等,了解细胞凋亡的机制对于这些疾病的治疗有着极为重要的意义。SIRT1除靶向组蛋白外,还作用于多种非组蛋白质例如转录因子和蛋白激酶等,其中有很多非组蛋白分子都与细胞凋亡息息相关。本文总结了SIRT1通过调控相关下游非组蛋白分子p53、叉头转录因子FOXO3a、AMP依赖的蛋白激酶(AMPK)、核转录因子NF-κB、ku70蛋白、转录因子E2F1和缺氧诱导因子-1α的乙酰化修饰水平,进而影响基因转录、DNA损伤修复、炎症、氧化应激等过程,直接或间接触发细胞凋亡的分子机制。希望通过调控SIRT1表达来影响其下游非组蛋白分子的乙酰化修饰水平,进而对细胞凋亡进行干预,为多种相关疾病的治疗提供新的靶点。展开更多
沉默信息调节因子2相关酶(silent mating type information regulator 2-related enzymes,Sirtuin)是烟酰胺腺嘌呤二核苷酸(nicotinamide adenine dinucleotide,NAD+)依赖性的去乙酰化酶。Sirt7是定位于核仁的Sirtuin蛋白家族成员,除了...沉默信息调节因子2相关酶(silent mating type information regulator 2-related enzymes,Sirtuin)是烟酰胺腺嘌呤二核苷酸(nicotinamide adenine dinucleotide,NAD+)依赖性的去乙酰化酶。Sirt7是定位于核仁的Sirtuin蛋白家族成员,除了具有去乙酰化酶活性外,还具有腺苷二磷酸(adenosine diphosphate,ADP)-核糖基转移酶、去琥珀酰化酶和去戊二酰化酶活性。Sirt7的作用底物包括组蛋白、DNA损伤修复相关因子、核仁小核糖核蛋白成分(核仁纤维蛋白、U3)、转录因子(GA结合蛋白β1(GA binding proteinβ1,GABPβ1)、叉头框蛋白O4、GATA4)、细胞周期蛋白依赖激酶9、组蛋白乙酰转移酶1、聚合酶相关因子53(polymerase associated factor 53,PAF53)、Ras相关核蛋白(Ras-related nuclear protein,Ran)、活化T细胞的核因子c1和p53等。另外,Sirt7还可以与损伤特异性DNA结合蛋白1(damage-specific DNA binding protein 1,DDB1)/cullin 4/DDB1-cullin 4相关因子1、Suv39h1/Sirt1、Myc、核呼吸因子1和Elk4等作用,进而调节其功能,但作用机制尚不清楚。Sirt7的多种活性使其在维持基因组稳定、调节RNA转录、抵御应激反应、调控代谢及炎症等病理生理活动中发挥重要作用。本文将介绍Sirt7在调节以上病理/生理活动中的作用机制,以及腺苷酸活化蛋白激酶(adenosine 5′-monophosphate activated protein kinase,AMPK)、蛋白质精氨酸甲基转移酶6、泛素特异性肽酶7等对Sirt7蛋白合成及活性的调节作用,并对目前Sirt7研究中存在的问题进行讨论。展开更多
目的分析青光眼术后干眼患者泪液中丝裂原活化蛋白激酶(mitogen-activated protein kinase,MAPK)、沉默信息调节因子相关酶1(silent information regulator of transcription1,Sirt1)水平与泪膜功能的关系。方法选择2015年9月到2017年1...目的分析青光眼术后干眼患者泪液中丝裂原活化蛋白激酶(mitogen-activated protein kinase,MAPK)、沉默信息调节因子相关酶1(silent information regulator of transcription1,Sirt1)水平与泪膜功能的关系。方法选择2015年9月到2017年12月在我院确诊的青光眼小梁切除术后干眼患者50例(50眼)为干眼组,选择同期行青光眼小梁切除术后未并发眼部疾病的患者50例(50眼)为对照组。采用Western blot检测两组患者泪液中p38MAPK、p-p38MAPK、JNK、p-JNK、ERK1/2、p-ERK1/2和Sirt1的蛋白表达水平;RT-PCR检测两组患者泪液中p38MAPK、JNK、ERK1/2和Sirt1 mRNA表达水平;检测两组患者泪膜破裂时间(BUT)、泪液分泌试验(Schirmer I test,SIt)和角膜荧光素染色(fluorescence staining,FL)评分;采用Pearson相关性分析各蛋白表达水平与泪膜功能之间的相关性。结果与对照组相比,干眼组患者泪液中p-p38MAPK、p-JNK、p-ERK1/2蛋白表达水平均显著增加(均为P<0.05),Sirt1蛋白和mRNA的表达水平均显著下降(均为P<0.05),p38MAPK、JNK和ERK1/2 mRNA的表达水平差异均无统计学意义(均为P>0.05),BUT和SIt均显著下降(均为P<0.001),FL评分显著升高(P<0.001)。干眼组患者泪液中p-p38MAPK、p-JNK、p-ERK1/2蛋白表达水平与BUT和SIt均呈显著负相关,与FL评分呈显著正相关(均为P<0.001);泪液中Sirt1蛋白表达水平与BUT和SIt均呈显著正相关,与FL评分呈显著负相关关系(均为P<0.001)。结论青光眼术后干眼患者泪液中MAPK、Sirt1水平与泪膜功能显著相关。展开更多
基金National Natural Science Foundation of China(81560666)Program for Excellent Young Talents of Zunyi Medical Uiverstity(15zy-002)+1 种基金Science and Technology Innovation Talent Team of Guizhou Province(20154023)the ″Hundred″Level of High-level Innovative Talents in Guizhou Province(QKHRCPT 20165684)；and Program forChangjiang Scholars and Innovative ResearchTeam in University of China(IRT一17R113).
文摘OBJECTIVE To investigate icariside(ICS)Ⅱ protects against PC12 cel damage induced by oxygen-glucose deprivation and reoxygenation and explore its mechanism.METHODS The oxidative stress injury model was induced by oxygen-glucose deprivation/reoxygenation(OGD/R) 2 h/24 h in PC12 cells.N-acetyl-lcysteine(NAC),a classical anti-oxidant,was used as positive control.Pharmacodynamic experimental study groups as follows:control,control+ICS Ⅱ50 μmol·L^(-1),OGD/R,OGD/R+ICSⅡ 12.5 μmol·L^(-1),OGD/R + ICS Ⅱ 25 μmol·L^(-1),OGD/R + ICS Ⅱ50 μmol·L^(-1),and OGD/R+NAC 100 μmol·L^(-1) groups.Cell viability and lactate dehydrogenase(LDH) leakage rate were measured by MTT assay and LDH ELISA kit,respectively.Moreover,reactive oxygen species(ROS) ELISA kit was used for detection of intracellular ROS generation,Mito-SOX fluorescence staining was used for detecting production of ROS in mitochondria and mitochondrial membrane potential(MMP)was detected by rhodamine 123 dye.In addition,PC12 cells apoptosis was detected by one-step TUNEL assay.Furthermore,the expressions of nuclear factor erythroid 2-related factors(Nrf2),Keap1,HO^(-1),NQO^(-1),silent information regulator 3(SIRT3),IDH2,Bax,Bcl-2 and caspase 3 were detected by Western blotting analysis.RESULTS The results of MTT and LDH assay showed that OGD/R reduced the cell viability and improved LDH release compared with the control or ICSⅡ 50 μmol·L^(-1) alone(P<0.01).Meanwhile,OGD/R not only increased intracellular and mitochondrial ROS generation,but also elevated the fluorescence intensity of TUNEL staining,at the same time,the MMP was declined when challenged by OGD/R.Furthermore,the Western blotting results showed that OGD/R induced the increase in the expression of cytoplasm-Nrf2,Keap1,Bax and cleaved-caspase 3 level,while the decrease in the expression of nucleus-Nrf2,HO^(-1),NQO^(-1),SIRT3,IDH2 and Bcl-2(P<0.05).However,ICS Ⅱ significantly increased the viability of PC12 cells and reduced LDH leakage(P<0.01).Notably,ICS Ⅱ also suppressed ROS generation both in the intracellular and mitochondria,as well as restored MMP.It was also worthy to note that ICS Ⅱ decreased the expressions of cytoplasmNrf2,Keap1,Bax and the level of cleaved-caspase3,whereas,it increased the expressions of nucleus-Nrf2,HO^(-1),NQO^(-1),SIRT3,IDH2 and Bcl-2(P<0.05).CONCLUSION ICSⅡ reduced OGD/Rinduced oxidative damage in PC12 cells under the laboratory conditions,and its underlying mechanism may be related to the regulation of Nrf2/SIRT3 signaling pathway.
文摘Sirtuin家族是酵母沉默信息调节因子(silent information regulator factor)在哺乳动物中的同源物,属于Ⅲ类组蛋白去乙酰化酶。沉默信息调节因子2相关酶1(silent information regulator factor 2-related enzyme 1,SIRT1)是Sirtuin家族目前研究最为充分的成员之一。主要分布于细胞核及细胞质,通过行使其NAD+依赖的去乙酰化活性,参与调节DNA损伤修复、基因转录、能量代谢、应激及凋亡等细胞生理过程。细胞凋亡是在精确的内在遗传调控下发生的一种程序性死亡,旨在维持机体内环境稳态。异常的细胞凋亡参与多种疾病的发生,例如肿瘤、神经退行性病变、自身免疫病和缺血性疾病等,了解细胞凋亡的机制对于这些疾病的治疗有着极为重要的意义。SIRT1除靶向组蛋白外,还作用于多种非组蛋白质例如转录因子和蛋白激酶等,其中有很多非组蛋白分子都与细胞凋亡息息相关。本文总结了SIRT1通过调控相关下游非组蛋白分子p53、叉头转录因子FOXO3a、AMP依赖的蛋白激酶(AMPK)、核转录因子NF-κB、ku70蛋白、转录因子E2F1和缺氧诱导因子-1α的乙酰化修饰水平,进而影响基因转录、DNA损伤修复、炎症、氧化应激等过程,直接或间接触发细胞凋亡的分子机制。希望通过调控SIRT1表达来影响其下游非组蛋白分子的乙酰化修饰水平,进而对细胞凋亡进行干预,为多种相关疾病的治疗提供新的靶点。
文摘目的分析青光眼术后干眼患者泪液中丝裂原活化蛋白激酶(mitogen-activated protein kinase,MAPK)、沉默信息调节因子相关酶1(silent information regulator of transcription1,Sirt1)水平与泪膜功能的关系。方法选择2015年9月到2017年12月在我院确诊的青光眼小梁切除术后干眼患者50例(50眼)为干眼组,选择同期行青光眼小梁切除术后未并发眼部疾病的患者50例(50眼)为对照组。采用Western blot检测两组患者泪液中p38MAPK、p-p38MAPK、JNK、p-JNK、ERK1/2、p-ERK1/2和Sirt1的蛋白表达水平;RT-PCR检测两组患者泪液中p38MAPK、JNK、ERK1/2和Sirt1 mRNA表达水平;检测两组患者泪膜破裂时间(BUT)、泪液分泌试验(Schirmer I test,SIt)和角膜荧光素染色(fluorescence staining,FL)评分;采用Pearson相关性分析各蛋白表达水平与泪膜功能之间的相关性。结果与对照组相比,干眼组患者泪液中p-p38MAPK、p-JNK、p-ERK1/2蛋白表达水平均显著增加(均为P<0.05),Sirt1蛋白和mRNA的表达水平均显著下降(均为P<0.05),p38MAPK、JNK和ERK1/2 mRNA的表达水平差异均无统计学意义(均为P>0.05),BUT和SIt均显著下降(均为P<0.001),FL评分显著升高(P<0.001)。干眼组患者泪液中p-p38MAPK、p-JNK、p-ERK1/2蛋白表达水平与BUT和SIt均呈显著负相关,与FL评分呈显著正相关(均为P<0.001);泪液中Sirt1蛋白表达水平与BUT和SIt均呈显著正相关,与FL评分呈显著负相关关系(均为P<0.001)。结论青光眼术后干眼患者泪液中MAPK、Sirt1水平与泪膜功能显著相关。
