不同缺血处理方法对大鼠压疮细胞凋亡的影响

目的 研究缺血处理对大鼠缺血再灌注性压疮细胞凋亡的影响.方法 应用空气压缩机制成缺血再灌注组(IR组)、缺血预处理组(IPC组)、缺血后处理组(Ⅰ-PostC组)压疮模型,同时设立正常大鼠为空白组(S组),采用AnnexinV-FITC联合PI双染流式细胞术检测各组细胞凋亡百分率.结果 IPC组和I-PostC组的凋亡率较低,分别为(5.8±1.03)％和(5.5±1.09)％,同时,S组细胞凋亡现象罕见,凋亡率为(1.0±1.07)％,而IR组凋亡情况较严重,凋亡率为(9.5±5.60)％,差异有统计学意义(P＜0.001);进一步两两比较发现,S组与IR组、S组与IPC组、S组与Ⅰ-PostC组、IR组与Ⅰ-PostC组、IR组与IPC组差异有统计学意义(P＜0.05),IPC组与Ⅰ-PostC组差异无统计学意义(P＞0.05).结论 缺血再灌注能诱发大鼠细胞凋亡的发生,缺血处理可降低细胞凋亡的发生率,缺血预处理和后处理对降低压疮细胞凋亡率的效果相似.     

缺血处理降低大鼠缺血再灌注性压疮细胞凋亡的实验研究

目的：研究缺血处理对大鼠缺血再灌注性压疮细胞凋亡的影响。方法应用空气压缩机制成缺血再灌注组（IR组）、缺血预处理组（IPC组）、缺血后处理组（I-Post C组）压疮模型,同时设立正常大鼠为空白组（S组）,每组20只。采用Annexin V-FITC/PI（膜联蛋白A 5-绿色荧光素/碘化丙啶）双染流式细胞术检测各组细胞凋亡百分率。结果 IPC组及I-Post C组所对应的大鼠细胞凋亡率水平较低,IPC组细胞凋亡率为（5.80±1.03）%、I-Post C组细胞凋亡率为（5.50±1.09）%。细胞凋亡在S组内罕见,其细胞凋亡率仅为（1.00±0.07）%。IR组所对应大鼠细胞凋亡情况相对严重,其细胞凋亡率达到（9.50±5.60）%。IR组细胞凋亡率明显高于其他3组,差异有统计学意义（P＜0.001）。S组与IR组、IR组与IPC组、IR组与I-postC组、IPC组与I-postC组,在细胞凋亡率方面,组间差异无统计学意义。结论缺血再灌注能诱发大鼠细胞凋亡的发生,缺血处理可降低细胞凋亡的发生率,缺血预处理和后处理对降低压疮细胞凋亡率的疗效相似。     

葛根素预处理对缺血再灌注心肌内质网应激与细胞凋亡的影响

目的：观察葛根素预处理对缺血再灌注（I/R）大鼠心肌内质网应激（ERS）与细胞凋亡的影响。方法24只SD大鼠随机分为3组（n=8）：假手术组（SH组）;缺血再灌注组（I/R组）;葛根素预处理组（PU组）。RT-PCR检测GRP78、CRT mRNA的表达;免疫组化检测caspase-12、CHOP蛋白表达;TUNEL法检测心肌细胞凋亡情况。结果与SH组比较,其余各组GRP78与CRT mRNA表达、caspase-12与CHOP蛋白表达以及心肌细胞凋亡率均明显增加（P〈0.05）,与I/R组比较,PU组各检测指标均降低（P〈0.05）。结论葛根素预处理可通过调控ERS反应程度,抑制I/R导致的过度ERS,减轻内质网凋亡信号介导的细胞凋亡的发生而产生心肌保护作用。     

内质网应激及其相关性凋亡与缺血性脑损伤

1细胞凋亡与缺血性脑损伤 内质网（endoplasmic reticulum，ER）在细胞内分布广泛，是真核细胞中重要的细胞器，其内膜表面积占细胞所有膜结构的50％，体积占细胞总体积的10％，参与重要的生理功能的维持，其基本生理功能包括负责蛋白质的合成转运、信号肽识别、糖基化修饰等过程以及钙离子的贮存和调节，信号转导及细胞内钙的再分布。内质网巨大的膜结构为细胞内活性物质的反应提供了一个广阔的平台，     

雌激素对内质网应激介导的大鼠脑缺血再灌注损伤的保护作用

目的观察雌激素对大鼠脑缺血/再灌注损伤的保护作用,并进一步探讨内质网应激在其中的作用。方法 250 g左右SD大鼠随机分为假手术组、模型组、雌激素(E2)预处理组,采用大脑中动脉阻塞(MCAO)法建立缺血2 h,再灌注22 h模型;5分法进行神经行为学评分、干湿重法测定脑水肿程度、利用HE染色观察鼠脑组织形态学改变,RT-PCR技术检测GRP78mRNA的表达。结果 (1)假手术组神经行为学评分、组织细胞形态无明显异常,脑组织含水量呈基础水平;模型组神经行为学评分显著升高;HE染色出现明显病理学改变,神经细胞及胶质细胞肿胀,胞核碎裂或消失,部分神经细胞坏死消失,残存神经细胞胞体缩小,胞核固缩,核仁消失,脑水肿明显(P<0.05);E2预处理组与模型组相比神经行为学评分降低,组织病理改变较轻,脑水肿减轻。(2)假手术组鼠脑GRP78 mRNA有一定表达,缺血/再灌注损伤时表达增加,E2预处理可下调其表达。结论雌激素可能通过抑制内质网应激途径减轻大鼠脑缺血/再灌注损伤。     

红景天苷抑制内质网应激和细胞凋亡减轻心脏缺血再灌注损伤

目的 观察红景天苷(Sal)在大鼠离体心脏缺血再灌注(IR)中的作用并探讨其对内质网应激(ERS)和细胞凋亡的调控机制。方法 制备大鼠离体心脏缺血再灌注模型,缺血45 min,再灌注2 h,随机分为4组(n=10):对照(Control)组、Sal处理(Sal)组、缺血再灌注(IR)组及Sal处理缺血再灌注(IR+Sal)组。氯化三苯基四氮唑(TTC)染色检测心肌梗死面积,ELISA法检测灌注液中乳酸脱氢酶(LDH)活性,测量左室内收缩峰压(LVSP)和舒张末压(LVEDP),Western blot检测B淋巴细胞瘤2基因(Bcl-2)及蛋白激酶R样内质网激酶(PERK)、Bcl-2相关X蛋白(Bax)、转录因子C/EBP同源蛋白(CHOP)和转录活化因子6(ATF6)的表达,TUNEL染色观察细胞凋亡。结果 Sal组和Control组各指标之间比较差异均无统计学意义;与Control组比较,IR组心肌梗死面积和灌注液中LDH活性增加,LVSP降低,LVEDP增加,Bax表达增加,Bcl-2表达减少,TUNEL阳性细胞数增加,ERS相关蛋白PERK、CHOP和ATF6的表达增加;与IR...     

大鼠压疮局部不同温度治疗对PI3K/Akt/GSK3β 信号通路的影响

目的 探讨不同局部温度对大鼠压疮PI3K/Akt/GSK3β 通路的影响,为压疮的临床治疗提供基础实验依据。方法 用缺血再灌注（IRI）法复制大鼠压疮模型。将40 例无特定病原体级（SPF）健康成年雄性SD 大鼠随机分为4 组：假手术组（Sham 组）、常温IRI 组（NTI）、低温IRI 组（LTI）和高温IRI 组（HTI）。HE 染色观察骨骼肌病理变化;Western blot 检测Akt、GSK3β 的磷酸化情况;免疫荧光观察p-Akt、p-GSK3β 的表达情况。TUNEL 检测大鼠压疮组织细胞凋亡情况。结果 与常温IRI 组比较,高温IRI 组的骨骼肌细胞病理损伤加重,凋亡细胞增加,Western blot 和免疫荧光结果显示Akt 和GSK3β 的磷酸化水平均降低（P <0.05）;而低温IRI 组骨骼肌细胞病理损伤减轻,Western blot 和免疫荧光结果显示Akt 和GSK3β 的磷酸化水平均上升（P <0.05）。结论 局部高温能抑制Akt 和GSK3β 的磷酸化水平而加重大鼠压疮损伤,局部低温能提高Akt 和GSK3β 的磷酸化水平减轻大鼠压疮损伤。     

α-突触核蛋白对内质网应激及细胞凋亡影响

目的:构建α-突触核蛋白(α-synuclein,SNCA)和SNCA突变基因(SNCAmu)过表达转染293T细胞,观察内质网应激及细胞凋亡.方法:应用PCR技术扩增目的基因并插入慢病毒载体质粒,重组质粒的构建及包装293T细胞,转染24 h后用荧光显微镜观察绿色荧光蛋白(green fluorescent prot...     

大鼠肢体缺血再灌注损伤后细胞凋亡与Bcl-2和Bax蛋白表达的关系

目的：阐明细胞凋亡与Bcl-2和Bax蛋白表达在大鼠肢体缺血及再灌注不同时相中的变化和相互关系。方法：采用大鼠股动脉夹闭模型，阻断股动脉血流5h后进行再灌注。设立缺血组及再灌注组。再灌注组设立1、3、6、12、18、24h6个检测时相，检测肌肉组织中Bcl-2和Bax蛋白表达的变化情况(用免疫组化方法)，观察细胞凋亡现象(用原位末端标记法及电镜方法)。结果：随着再灌注时间的延长(24h内)。凋亡指数(AI)及Bax蛋白表达水平进行性升高，Bcl-2蛋白在短时间内升高，而后逐渐下降，Bcl-2／Bax比值逐渐降低；AI与Bax蛋白表达水平呈显著正相关，与Bcl-2蛋白表达水平呈显著负相关(3～24h)，与Bcl-2／Bax比值呈显著负相关。结论：肢体再灌注损伤的发生有细胞凋亡机制参与，Bcl-2/Bax的比例关系向促进细胞凋亡的方向发展。     

黄芪当归合剂对大鼠脑缺血再灌注后神经细胞凋亡及内质网应激的影响

目的:探讨黄芪当归合剂对大鼠脑缺血再灌注损伤后神经细胞凋亡及内质网应激的影响。方法:将SD大鼠随机分为4组,即假手术组、模型组、治疗组和溶剂对照组,每组3只。采用经典线栓法构建大鼠大脑中动脉缺血再灌注模型,TTC法检测缺血再灌注后脑组织坏死情况,TUNEL法检测缺血再灌注后神经细胞凋亡率,Western bloting法检测凋亡和内质网应激相关蛋白的表达情况。结果:缺血2 h再灌注48 h后,实验组脑组织均出现不同程度的缺血灶,各组细胞出现不同程度的凋亡;与模型组和溶剂对照组相比较,治疗组凋亡率明显减少(P<0.05),caspase-3、caspase-12蛋白的表达量明显降低(P<0.05),GRP78蛋白的表达量明显升高(P<0.05)。结论:黄芪当归合剂能够在一定程度上减少神经细胞凋亡,缓解内质网应激。     

氢气对大鼠局灶性脑缺血再灌注损伤内质网应激及神经细胞凋亡的影响

目的 探讨吸入高浓度氢气(H2)对大鼠局灶性脑缺血再灌注损伤(IRI)内质网应激(ERS)相关蛋白葡萄糖调节蛋白78(GRP78)、半胱氨酸蛋白酶12 (Caspase-12)及脑皮质神经细胞凋亡和凋亡相关蛋白Bcl-2、Bax表达的影响.方法 选取72只健康成年SPF级雄性SD大鼠,将其分为对照组(Ⅰ组:不作任何处理)、假手术组(Ⅱ组)、脑IRI组(Ⅲ组)、氢气治疗组(Ⅳ组),每组18只.采用线栓法建立大鼠局灶性脑IRI模型.于再灌注24 h后行神经功能缺损评分(NDS),采用2,3,5-氯化三苯基四氮唑(TTC)染色观察大鼠脑缺血梗死程度并计算脑梗死面积,原位末端标记法(TUNEL)技术检测各组大鼠脑皮质神经细胞凋亡并计算凋亡指数(AI),Western blot法和免疫组织化学法检测大鼠脑皮质GRP78、Caspase-12、Bcl-2及Bax蛋白表达.结果 与Ⅰ、Ⅱ组比较,Ⅲ、Ⅳ组大鼠脑IRI后NDS、脑梗死面积、AI均明显增加,GRP78、Caspase-12、Bax蛋白表达明显升高,Bcl-2蛋白表达明显下降(P＜0.05);与Ⅲ组比较,Ⅳ组大鼠NDS、脑梗死面积、AI及Caspase-12、Bax蛋白表达明显减少,GRP78、Bcl-2表达明显增加(P＜0.05).结论 再灌注同时吸入高浓度H2可通过增加脑IRI后内质网GRP78蛋白表达,并抑制Caspase-12的激活进而抑制ERS并促进内质网功能修复,对大鼠脑IRI起到一定的保护作用.     

热打击可通过调控内质网应激通路促进神经细胞凋亡

Objective To explore the role of endoplasmic reticulum stress in heat stress-induced apoptosis of human neuroblastoma SH-SY5Y cells. Methods SH-SY5Y cells were incubated at 43 ℃ for 2 h followed by further culture at 37 ℃ for 0, 3 h, or 6 h. With the cells cultured at 37 ℃ as the control, the cells exposed to heat stress were examined for morphological changes under optical microscope and changes in cell viability using CCK-8 assay. Flow cytometry was performed for detecting apoptosis of the cells following heat stress, and intracellular Ca2 + level in the cells was determined using flow cytometry and immunofluorescence confocal microscopy. The mRNA expression levels of caspase-12, BIP and XBP-1 in the cells were detected using qRT-PCR, and the protein expressions of caspase-12, BIP, P- JNK, JNK and XBP-1 were examined using Western blotting. The effect of pretreatment with 4-PBA on cell apoptosis following heat stress was analyzed with Western blotting. Results SH-SY5Y cells showed obvious cell shrinkage immediately after the exposure to heat stress, followed then by gradual cell stretching over time. The cell viability decreased significantly after heat stress (P=0.001), and the intracellular Ca2+ level increased significantly at 0 h and gradually recovered the normal level at 3 and 6 h. Heat stress induced significant increase in the protein expression of cleaved caspase-3 and time-dependent increase of caspase-12 (P=0.002) and BIP (P=0.008) expression at both the protein and mRNA levels. The expression of P-JNK/JNK protein increased significantly at 0 h (P=0.003) followed by gradual decrease; the expression levels of XBP-1 protein and mRNA gradually decreased after heat stress (P=0.005, P=0.002). Pretreatment with 4-PBA significantly reduced the expression level of cleaved caspase-3 in SH-SY5Y cells following heat stress. Conclusion Heat stress induces apoptosis of SH- SY5Y cells by triggering endoplasmic reticulum stress and the imbalance of intracellular calcium ion homeostasis.     

内质网与细胞凋亡

内质网 (endoplasmicreticulum ,ER)广泛存在于真核细胞中 ,是调节蛋白质合成及合成后折叠、聚集的场所 ,是调节细胞的应激反应及细胞钙水平的场所 ,也是胆固醇、类固醇及许多脂质合成的场所。ER应激在细胞凋亡中起重要作用 ,现就ER应激在细胞中的作用、ER应激与Ca2 + 水平的调节及与相关凋亡蛋白之间的关系等方面进行综述。     

Effects of endoplasmic reticulum stress and related apoptosis on selective death of dopaminergic neurons

Objective： To explore the mechanism of endoplasmic reticulum stress（ERS） response and related apoptosis in dopaminergic neurons death. Methods： Nerve growth factor （NGF）-treatedPC12 cells were treated with 6-OHDA, MPP^＋ and rotenone. MTT assay and flow cytometry were used to measure the cell viability and the rate of celluar apoptosis induced by those neurotoxins. The expression of ERS-related gene XBP1, Grp78, CHOP, caspase-12 in drug-treated group and reserpine preincubafion group was determined with RT-polymerase chain reaction（RT-PCR） and immunohistochemistry. Results： After the exposure to different toxins, the viability of PC12 cells were decreased by 52%, 44%, 40% at 100μM6-OHDA, 75 μM MPP^＋, 20 nM rotenone for 24 h respectively. FCM assay confirmed time-dependent cell apoptosis （P 〈 0.01 ）. The gene and protein expression of XBP1, Grp78 in drug-treated group were significantly increased and reached their peaks 8 h after the treatment（P 〈 0.05）. The expression levels of CHOP and caspase-12 gene were increased 16-24 h after the treatment（P 〈 0.01 ）, but the expression level of caspase-12 was inhibited by reserpine preincubayion（P 〈 0.05）. Conclusion： The excessive ERS and relative activated cell apoptosis pathway may be associated with selective death of dopaminergic neurons.     

Effects of lead exposure on placental cellular apoptosis and endoplasmic reticulum stress in rats

Background Lead exposure during pregnancy contributes to fetal abortion and/or teratogenesis.Endoplasmic reticulum （ER） apoptosis can be induced by various pathological conditions when ER function is disturbed.However,it is unclear whether ER stress and apoptosis play a role in the etiology of lead-exposed disease status.We aimed to investigate whether lead induced placental apoptosis and subsequent toxicity is initiated by ER apoptosis via caspase-12.Methods Sixty-three female Wistar rats were exposed to lead in drinking water during various gestational periods.Blood lead level was determined by atomic absorption spectrophotometry.Placental cytoplasmic organelles were examined by electronic microscopy.Placental caspase-12 mRNA expression was evaluated by qRT-PCR.TUNEL assay was used to determine the placental apoptosis.Results Lead exposure significant induced ER apoptosis compared to that of the controls （P ＜0.05）,accompanied with increased caspase-12 mRNA expression.Significant differences of caspase-12 mRNA expression levels were observed among the four groups （F=13.78,P ＜0.05）.Apoptotic index （AI） was significantly increased in experimental groups compared to that of the controls （F=96.15,P ＜0.05）.In lead-exposed groups,trophoblast cells underwent degeneration and fibrin deposition; Mitochondria were swollen and decreased in number; ER swelling,expansion,and vacuolization were observed.Conclusion Lead exposure contributes to placental apoptosis,as well as increased caspase-12 mRNA expression,which in turn promoted ER stress.     

内质网应激在UCH-L1抑制剂诱导细胞凋亡中的作用

目的探讨内质网应激(ERS)在泛素羧基末端水解酶-1(UCH-L1)抑制剂导致的细胞损伤过程中的作用。方法采用50μmol/L的UCH-L1抑制剂处理人神经母细胞瘤SK-N-SH细胞。于处理前(对照组)和处理后不同时间点(2、4、6、12、24h),分别采用MTT比色法和Western blotting法检测细胞活力和ERS相关蛋白Bip/Grp78、Xbp-1、p-eIF2α及其促凋亡转录因子CHOP/Gadd153的表达。结果MTT比色法检测发现,50μmol/LUCH-L1抑制剂处理后4h,SK-N-SH细胞活力下降43.1%(P<0.05),且随处理时间的延长继续呈现显著下降趋势(P<0.01)。Western blotting检测显示,经50μmol/LUCH-L1抑制剂处理后,SK-N-SH细胞ERS相关蛋白Bip/Grp78、p-eIF2α和Xbp-1表达分别于处理后2、4、6h时显著增加;转录因子CHOP/Gadd153表达则在处理后2h和4h时略有增加,6h后达到高峰。结论在UCH-L1抑制剂诱导的细胞凋亡过程中,ERS是导致细胞损伤的路径之一。     

缺糖缺氧对经内质网应激途径诱导Hela细胞凋亡的影响

目的：体外构建肿瘤细胞缺糖缺氧( OGD)模型,观察缺糖缺氧应激条件对肿瘤细胞凋亡的影响及其机制。方法：利用平衡盐溶液EBSS取代细胞正常培养液构建缺糖模型,利用连二亚硫酸钠消耗培养基中氧构建缺氧模型;实验分为对照组、缺糖缺氧4、8和12 h组。MTT法检测各组细胞增殖率;Western blotting检测各组Hel...     

高糖经内质网应激途径诱导胰岛内皮细胞凋亡

目的:探讨高糖诱导胰岛微血管内皮细胞株MS-1凋亡及其可能机制?方法:体外培养MS-1细胞,用含有不同浓度葡萄糖(5.6?25.0和33.6 mmol/L)的培养液分组培养12?24 h?流式细胞术分析各组细胞凋亡率变化;四甲基偶氮唑盐(MTT)法检测各组细胞增殖率变化;RT-PCR分析GRP78?CHOP?caspase-3?caspase-12 mRNA表达变化情况;Western blot分析GRP78?CHOP蛋白表达变化情况?结果:与5.6 mmol/L组相比,培养12 h及24 h后,25.0和33.6 mmol/L组MS-1细胞凋亡率显著增加(P < 0.05);而细胞增殖率显著下降(P < 0.05),且呈浓度和时间依赖性?进一步研究表明,在高糖刺激12 h及24 h后,caspase-3?caspase-12 mRNA表达显著上调(P < 0.05),CHOP mRNA和蛋白表达水平均显著上调(P < 0.05);而GRP78 mRNA和蛋白表达水平在刺激12 h后显著上调,24 h后却显著下降(P < 0.05)?结论:高糖可以促进胰岛内皮细胞凋亡增加,并呈浓度和时间依赖性升高,其机制可能与启动胰岛内皮细胞内质网应激有关?     

内质网应激在肝细胞凋亡中的意义

目的:探讨内质网应激在肝细胞凋亡中的意义。方法:原位二步灌流法分离并培养BALBC小鼠原代肝细胞,化学合成法制备抗半胱氨酸天冬氨酸蛋白酶-12小分子干扰RNA(caspase-12 siRNA),脂质体包裹转染小鼠原代肝细胞。毒胡萝卜内酯4μmol/L诱导肝细胞凋亡。RT-PCR、Western blot检测抑制效果;MTT比色试验检测细胞活力,反映细胞凋亡。结果:siRNA对小鼠原代肝细胞caspase-12 mRNA在浓度200nmol/L时抑制率为86.22%;对凋亡细胞procaspase-12抑制率为50.04%,与单纯诱导凋亡细胞差异有统计学意义(P<0.01);MTT比色试验检测发现,与单纯诱导凋亡细胞相比,转染siRNA后细胞活力增高51.65%,两者差异有统计学意义(P<0.05)。结论:抑制内质网应激介导细胞凋亡的特异酶caspase-12,能在一定程度上阻抑小鼠原代肝细胞凋亡的发生,内质网应激在肝细胞凋亡中具有重要意义。     

Dexamethasone protects airway epithelial cell line NCI-H292 against lipopolysaccharide induced endoplasmic reticulum stress and apoptosis

Background  Endoplasmic reticulum (ER) stress and ER stress-mediated apoptosis were reported to be involved in the pathogenesis of several diseases. In a recent study, it was reported that the ER stress pathway was activated in the lungs of lipopolysaccharide (LPS)-treated mice. It was also found that the C/EBP homologous protein (CHOP), an apoptosis-related molecule, played a key role in LPS-induced lung damage. The aim of this study was to verify whether LPS could activate the ER stress response in airway epithelial cells and which molecule was involved in the pathway. This study was also aimed at finding new reagents to protect the airway epithelial cells during LPS injury.

Methods  ER stress markers were observed in LPS-incubated NCI-H292 cells. SiRNA-MUC5AC was transfected into NCI-H292 cells. The effects of dexamethasone and erythromycin were observed in LPS-induced NCI-H292 cells.

Results  LPS incubation increased the expression of ER stress markers at the protein and mRNA levels. The knockout of MUC5AC in cells attenuated the increase in ER stress markers after incubation with LPS. Dexamethasone and erythromycin decreased caspase-3 activity in LPS-induced NCI-H292 cells.

Conclusions  LPS may activate ER stress through the overexpression of MUC5AC. Dexamethasone may protect human airway epithelial cells against ER stress-related apoptosis by attenuating the overload of MUC5AC.