青藤碱对大鼠海马神经元缺血损伤的保护作用

目的观察青藤碱(sinomenine,SN)对氧糖剥夺(oxygen glucose deprivation,OGD)诱导海马神经元缺血损伤的保护作用并探讨其机制。方法原代培养海马神经元OGD 2h后复灌24 h(OGD-R),MTT法和LDH试剂盒分别检测各组细胞存活率和乳酸脱氢酶(lactate dehydrogenase,LDH)释放量;Hoechst染色检测细胞凋亡;Westren blot检测凋亡相关蛋白表达;荧光钙离子成像系统检测[Ca2+]i,全细胞膜片钳技术记录酸敏感离子通道(acid-sensing ion channels,ASICs)电流。结果不同浓度SN均能抑制OGD-R诱导的海马神经元存活率降低和LDH释放增多;SN能明显抑制OGD-R诱导的神经元凋亡、Bcl-2/Bax比值的下降、caspase-3表达的增加以及胞内钙浓度升高,SN还能抑制海马神经元ASIC1a电流,也能抑制OGD诱导的ASICs电流增加。结论 SN对OGD诱导海马神经元损伤有保护作用,其机制可能与抑制ASICs通道减轻钙超载相关。     

CRMP2可通过改善神经细胞凋亡减轻缺血/再灌注大鼠神经功能缺损

目的探讨CRMP2(collapsin response mediator protein2)对大鼠脑缺血/再灌注损伤后神经细胞凋亡的影响及其可能的机制。方法 192只♂成年SD大鼠分成4组:假手术组(sham)、脑缺血/再灌注组(MCAO)、脑缺血+质粒对照组(MCAO+GFP)、脑缺血+CRMP2真核质粒干预组(MCAO+CRMP2/GFP)。大鼠MCA阻塞手术前1 d将真核质粒注射入脑内,缺血/再灌注后48 h、1周,采用RT-PCR检测各组大鼠脑组织CRMP2、BCL2、p53、Caspase-3和Caspase-8的mRNA的表达;Western blot检测脑组织CRMP2蛋白的表达;TUNEL染色检测凋亡细胞;免疫组化检测脑源性神经营养因子(brain derived neurotrophic factor,BDNF)的表达;TTC染色检测脑梗死体积并进行神经功能缺损评分。结果脑缺血/再灌注48 h及1周,与sham组比较,MCAO组及MCAO+GFP组CRMP2和BCL2的表达水平明显降低(P<0.01),而Caspase-3、Caspase-8及p53的mRNA表达升高(P<0.01),TUNEL阳性细胞数量明显升高(P<0.01)。MCAO+CRMP2/GFP组CRMP2和BCL2较MCAO及MCAO+GFP组明显增高(P<0.01),同时该组p53、Caspase-3及Caspase-8表达明显降低(P<0.01)。过表达CRMP2使TUNEL阳性细胞数明显减少(P<0.01)。脑缺血/再灌注后BDNF表达升高(P<0.01),而脑内过表达CRMP2使BDNF的水平上调更明显(P<0.01)。TTC染色显示,MCAO+CRMP2/GFP组脑梗死体积较MCAO组及MCAO+GFP组明显减小(P<0.01),且神经功能缺损明显减轻(P<0.01)。结论过表达CRMP2可能通过对线粒体凋亡通路的调控减少了脑缺血/再灌注损伤后的神经细胞凋亡、减少脑梗死体积而起到神经保护作用。     

对羟基苯甲醛对脑缺血/再灌注损伤的保护作用研究

目的探讨天麻酚性成分4-HBd对脑缺血/再灌注损伤的保护作用及机制。方法复制大鼠脑缺血/再灌注损伤模型,各组动物脑缺血2 h,再灌注24 h,以神经病学评分、脑梗死体积评价4-HBd对脑缺血/再灌注损伤的保护作用;化学法(连二亚硫酸钠)复制原代皮层神经元OGD/Rep损伤模型,检测细胞存活率、MDA含量、SOD活性、NO释放量以及Bax、Bcl-2、caspase-3蛋白的表达,探讨其脑保护作用的可能机制。结果 4-HBd可降低MCAO/R模型大鼠的神经病学评分(P<0.05)、脑梗死体积(P<0.01),提高OGD/Rep损伤原代皮层神经元的细胞存活率(P<0.05)、SOD的活性(P<0.05),降低模型细胞MDA的含量(P<0.05)、NO的释放量(P<0.05),并能下调模型细胞Bax的表达水平(P<0.05)、上调Bcl-2的表达水平(P<0.05),下调Bax/Bcl-2的比值(P<0.05),最终下调caspase-3的表达水平(P<0.05)。结论 4-HBd对脑缺血/再灌注损伤有保护作用,其机制可能与提高SOD活性、降低MDA含量、减少NO释放、下调Bax蛋白表达、上调Bcl-2蛋白表达、下调caspase-3蛋白表达,进而对抗神经细胞凋亡有关。     

呫吨酮并吡啶衍生物XP-16诱导人肺癌A549细胞凋亡

目的探讨呫吨酮并吡啶衍生物5,9-二(2-吡咯烷基乙酰氨基)-7H-吡啶并[4,3-c]呫吨-7-酮(XP-16)对人肺癌A549细胞的抗肿瘤作用及其可能作用机制。方法通过MTT法、细胞形态学和克隆实验观察XP-16对A549细胞增殖的影响;应用Hoechst 33258和PI双染法观察细胞凋亡;荧光分光光度计检测细胞内钙([Ca2+]i)及线粒体膜电位;qRT-PCR检测Bad和金属硫蛋白1A(metallothionein 1A,MT-1A)mRNA表达。结果 XP-16能抑制A549细胞增殖,呈剂量和时间依赖性。XP-16作用A549细胞24 h后,A549细胞出现染色质聚集、核碎裂等典型的凋亡形态学改变;随XP-16剂量的增加,A549细胞凋亡百分率逐渐增大。XP-16作用后,A549细胞的[Ca2+]i和线粒体膜电位降低、Bad和MT-1A mRNA的表达增加。结论 XP-16具有诱导A549细胞凋亡的作用,可能与其降低[Ca2+]i和线粒体膜电位有关。MT-1A表达的上调可能是[Ca2+]i降低的结果。     

BAPTA-AM对MDCK细胞的保护作用及其机制

目的观察BAPTA-AM抗D-氨基半乳糖(D-GalN)诱导MDCK细胞损伤作用,探讨其作用机制。方法采用MTT法,Annexin V-EGFP/PI与Hoechst33342/PI荧光染色,罗丹明123(Rhodamine 123)荧光染色,Caspase-8、Caspase-9活性测定及钙离子载体A23187诱导细胞内高钙等方法,分别测定D-GalN攻击下MDCK细胞活性,细胞凋亡状况,线粒体膜电位(△Ψm)、Caspase-8、Caspase-9活性和细胞内游离钙浓度([Ca2+]i)变化等。结果 BAPTA-AM能明显抑制D-GalN所致的细胞活力下降、减少细胞凋亡、维持△Ψm,抑制Caspase-8、Caspase-9的激活,减轻A23187所致细胞损伤,降低[Ca2+]i。结论 BAPTA-AM通过减轻钙超载,保护线粒体、抑制外源及内源性凋亡通路的激活,发挥抗肾细胞凋亡作用。     

牛磺酸对皮质神经元急性氧糖缺失所致损伤的保护作用(英文)

目的已证实牛磺酸对在体脑缺血有保护作用,本研究观察其对缺失氧糖的离体神经元是否有直接的保护作用及可能的作用机制。方法制备离体大鼠脑皮质神经元的氧糖缺失模型。在氧糖缺失前20 h及氧糖缺失4 h过程中,分别给予牛磺酸5,10和20 mmol·L-1。MTT法和流式细胞术检测神经元的死亡率;Fura-2/AM负载检测神经元内游离钙离子水平([Ca2 +]i);高效液相色谱法检测培养基中谷氨酸水平。结果氧糖缺失可致神经元死亡增加,[Ca2 +]i和培养基中谷氨酸水平异常升高;牛磺酸处理可使氧糖缺失引起的神经元死亡率明显降低,抑制氧糖缺失引起的神经元[Ca2 +]i和胞外谷氨酸浓度的异常升高。结论牛磺酸可以减轻氧糖缺失引起的大鼠皮质神经元损伤,其机制可能与其抑制胞内钙超载和抑制谷氨酸释放或漏出有关。     

大鼠脑缺血/再灌注后神经元凋亡及caspase-12 mRNA和蛋白表达的改变

目的研究大鼠局灶性脑缺血/再灌注后caspase-12 mRNA及蛋白的表达,明确内质网信号通路在脑缺血后神经元凋亡调控中的作用。方法60只Wistar♂大鼠随机分为假手术组和缺血组。应用线栓法制备大鼠大脑中动脉缺血/再灌注模型,应用原位末端标记法(TUNEL)、免疫组化染色、RT-PCR技术检测脑缺血/再灌注后各组凋亡细胞数和caspase-12 mRNA及蛋白的表达。结果脑缺血/再灌注后,随着再灌注时间的延长,凋亡细胞数和caspase-12mRNA及蛋白的表达逐渐增高。在脑缺血/再灌注后24h达高峰。与假手术组相比,缺血组在各时间点凋亡细胞数、caspase-12 mRNA及蛋白表达均明显升高(P<0.01)。结论脑缺血/再灌注后神经元凋亡数明显增高,caspase-12 mRNA及蛋白的表达明显升高,提示内质网通路参与了脑缺血/再灌注后神经元凋亡的调控。     

青蒿琥酯对人前列腺癌PC-3细胞内游离Ca~(2+)的影响

目的:研究青蒿琥酯(ART)对人前列腺癌PC-3细胞内游离Ca2+浓度([Ca2+]i)的影响。方法:ART处理PC-3细胞,用Ca2+荧光探针Fluo-3/AM标记PC-3细胞,激光共聚焦扫描显微镜检测PC-3细胞内[Ca2+]i变化。结果:ART诱导PC-3细胞内[Ca2+]i在0～0.5h显著升高;在0.5～1h维持高水平;在4～24h降到初始水平。结论:ART能够诱导PC-3细胞内[Ca2+]i显著持续升高,[Ca2+]i升高可能在ART诱导PC-3细胞凋亡中起重要作用。     

ATP对大鼠三叉神经节小直径神经元胞内钙浓度的调制作用及其机制

目的探讨神经递质ATP通过何种途径引起大鼠三叉神经节(trigeminal ganglion,TG)小直径神经元胞内钙离子浓度升高。方法在急性分离的TG神经元上,应用钙离子成像技术检测胞内游离Ca2+浓度([Ca2+]i)的变化。结果在大鼠TG小直径神经元中,ATP(100μmol·L-1),thap-sigargin(1μmol·L-1,内质网钙泵抑制剂)和咖啡因(20mmol·L-1,内质网钙离子通道开放剂)在正常细胞外液和去除细胞外Ca2+的情况下,均能够引起细胞[Ca2+]i升高。在细胞外无Ca2+条件下,thapsigargin能够可逆地抑制ATP引起细胞内[Ca2+]i升高(n=8,P<0.01),而咖啡因对ATP引起的细胞内[Ca2+]i升高无影响(n=6,P>0.05)。然而在正常外液中,thapsigargin不能完全抑制ATP引起的细胞内[Ca2+]i升高,不过ATP引起的细胞内[Ca2+]i升高的幅度明显地低于thapsigargin处理前(n=7,P<0.05)。结论在大鼠TG小直径神经元中,存在有IP3敏感钙库和Ryanod-ine敏感钙库。ATP可通过激动P2Y受体引起IP3敏感钙库的Ca2+释放,也可通过激动P2X受体引起细胞外钙内流。     

人参炔醇对大鼠主动脉平滑肌细胞增殖的抑制作用及机制

目的观察人参炔醇(panaxynol,PNN)对大鼠主动脉平滑肌细胞(RASMC)增殖的抑制作用及机制。方法由细胞计数、[3H]TdR参入试验确定细胞增殖率,采用分子探针Fura-3/AM及共聚焦显微镜检测胞内游离Ca2+浓度([Ca2+]i),RT-PCR方法观察线粒体转录因子1(m tTF1)mRNA的表达。结果PNN以浓度依赖方式抑制血清及PDGF-BB诱导的RASMC增殖和DNA合成;9μmol.L-1PNN预处理RASMC能抑制PDGF-BB引起的[Ca2+]i升高;PDGF-BB上调RASMC m tTF1 mRNA表达,该作用可被3、9μmol.L-1的PNN抑制。结论PNN具有抗RASMC增殖作用,该作用与降低[Ca2+]i和抑制m tTF1 mRNA表达有关。     

三七总皂苷对大鼠脑缺血再灌注后Caspase表达的影响

目的研究大鼠局灶性脑缺血再灌注后脑组织中天冬氨酸特异性半胱氨酸蛋白酶(Caspase-1、Caspase-3、Caspase-8)蛋白表达的变化,以及三七总皂苷(PNS)对其表达的影响。方法采用线栓法建立大鼠大脑中动脉栓塞局灶性脑缺血再灌注模型。实验动物随机分为假手术组、模型组、三七总皂苷组和尼莫地平对照组,于缺血前5 m in、缺血后12、24、36 h给药,共给药4次。缺血2 h再灌注46 h后,采用免疫组织化学方法检测脑组织中Caspase-1、Caspase-3、Caspase-8蛋白表达的变化。结果缺血2 h再灌注46 h后,可诱导脑组织Caspase-1、Caspase-3表达增强,PNS能下调Caspase-1、Caspase-3蛋白的表达;但对Caspase-8的表达无影响。结论PNS能抑制脑缺血再灌注后Caspase-1、Caspase-3蛋白的表达,这可能是其促进脑缺血后神经元存活及损伤后修复的机制之一。     

The neuroprotection of Sinomenine against ischemic stroke in mice by suppressing NLRP3 inflammasome via AMPK signaling

Neuroinflammation remains the primary cause of morbidity and mortality in stroke-induced secondary brain injury. The NOD-like receptor pyrin 3 (NLRP3) inflammasome is involved in diverse inflammatory diseases, including cerebral ischemia, and is thus considered an effective therapeutic target. In the present study, we investigated the neuroprotection of Sinomenine (SINO), a potent natural anti-apoptotic and anti-inflammatory molecule, against cerebral ischemia in a mouse model of middle cerebral artery occlusion (MCAO) in vivo and in an oxygen glucose deprivation (OGD)-treated astrocytes/microglia model in vitro. SINO administration intraperitoneally alleviated the cerebral infarction, brain edema, neuronal apoptosis, and neurological deficiency after MCAO induction. SINO also attenuated astrocytic and microglial activation in the ischemic hemisphere. NLRP3 inflammasome activation after MCAO and OGD induction, with the up-regulation of NLRP3, apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC), cleaved caspase-1 and pro-inflammatory cytokines, was significantly inhibited by SINO treatment both in vivo and in vitro. In addition, SINO reversed the OGD-induced inhibition of AMPK phosphorylation in vitro. Further, the suppressive effect of SINO on NLRP3 inflammasomes was blocked by an AMPK inhibitor, Compound C. Our findings demonstrate that SINO exerts a neuroprotective effect in ischemic stroke by inhibiting NLRP3 inflammasomes via the AMPK pathway, which also provides evidence of a novel treatment for clinical stroke therapy.     

Ischemic insult induced apoptotic changes in PC12 cells: protection by trans resveratrol

In this study, we determined the protective potential of trans resveratrol against oxygen-glucose deprivation (OGD) induced reactive oxygen species mediated apoptotic damages in PC12 cells. In vitro model of ischemic cerebral stroke was created by keeping cells in an OGD condition for 6h followed by 24h reoxygenation. Cells received biologically safe doses (5, 10, and 25 μM) of trans resveratrol in the following schedules for 24h prior to OGD; during 6h of OGD; for 24h post OGD and whole treatment group which starts from 24h before OGD and lasted to 24h post OGD. Anti-ischemic potential of trans resveratrol was assessed by measuring the regulation of lipid peroxidation, reactive oxygen species production, glutathione content, and expression (mRNA and protein) of apoptotic markers such as Bax, Bcl(2) and Caspase-3. Hypoxia inducible factor-1α (HIF-1α) was also assessed to correlate the changes with ischemic injuries. Significant (P<0.05) restoration in lipid peroxidation, reactive oxygen species, and glutathione content were observed following the treatment of trans resveratrol in cells receiving OGD and re-oxygenation. Changes induced by trans resveratrol could be correlated well with alterations in the expression of Bax, Bcl(2), Caspase-3 and HIF-1α. These results indicate that trans resveratrol administration attenuates free radical formation and mitochondria mediated apoptosis perhaps by regulating the expressions of Bax, Bcl(2,) and Caspase-3 in PC12 cells receiving OGD and re-oxygenation insult.     

法舒地尔可能通过PI3-K/Akt信号通路抑制大鼠脑缺血/再灌注区神经元的凋亡

目的探讨法舒地尔对大鼠脑缺血/再灌注损伤神经元是否具有抗凋亡作用并探讨其抗凋亡机制。方法大脑中动脉线栓法制作大鼠局灶性脑缺血/再灌注损伤模型。运用TUNEL法检测大鼠脑缺血/再灌注区神经细胞的凋亡,免疫组化法检测Bcl-2、Bax、Caspase-3蛋白的表达,Western blot法检测Akt以及Rho激酶特异性底物蛋白MYPT的磷酸化表达。结果法舒地尔能明显减少TUNEL染色阳性细胞数,增加Bcl-2的表达,降低Bax、Caspase-3的表达,升高Akt的磷酸化水平以及降低MYPT的磷酸化水平。结论①法舒地尔能减少大鼠脑缺血/再灌注区神经细胞凋亡。②法舒地尔的抗凋亡机制可能与其抑制Rho激酶活性,进而激活PI3-K/Akt传导通路有关。     

激动γ-羟基丁酸受体对大鼠局灶性脑缺血/再灌注神经细胞凋亡的影响

目的研究γ-羟基丁酸受体(gamma-hydroxybutyrate receptor,GHBR)对大鼠局灶性脑缺血/再灌注神经细胞凋亡的影响。方法成年♂SD大鼠,分为假手术组(Sham),缺血/再灌注(Isc/R),NCS-356160、320、640μg.kg-1组(N1、N2、N3),NCS-382640+NCS-356640μg.kg-1组(NCS-382+N3),尼莫地平600μg.kg-1组(Nim)。采用改良的Longa法制备大鼠大脑中动脉栓塞(MCAO)模型。再灌24h后,一部分动物应用免疫组织化学染色法测定大鼠缺血侧大脑皮质Bax,Bcl-2,Caspase-3蛋白的表达,另一部分动物应用流式细胞仪测定神经细胞凋亡率。结果NCS-356160、320、640μg.kg-1及Nim增加缺血神经细胞的Bcl-2表达和Bcl-2/Bax比值,降低Bax、Caspase-3阳性细胞数和细胞凋亡百分率,上述作用可被NCS-382拮抗。结论激动GHBR可抑制大鼠局灶性脑缺血/再灌注损伤引起的细胞凋亡。     

雷公藤多苷对大鼠局灶性脑缺血再灌注损伤的保护作用

目的:观察雷公藤多苷(TwP)对局灶性脑缺血再灌注损伤大鼠的保护作用。方法:180只大鼠随机分为脑缺血再灌注组,TwP大、中、小剂量组,阳性对照组,假手术组。灌胃给药,采用大脑中动脉局灶性缺血再灌注模型,测定再灌注2 h缺血侧脑组织含水量、超氧化物歧化酶(SOD)、丙二醛含量及大脑皮层神经元细胞内[Ca2+]i水平。结果:与假手术组相比,脑缺血再灌注组脑组织丙二醛含量增加、SOD活性降低、含水量及[Ca2+]i显著升高(P<0.01);与脑缺血再灌注组相比,TwP大、中、小剂量组,阳性对照组脑组织丙二醛含量减少、SOD活性升高、[Ca2+]i显著下降(P<0.01或P<0.05),TwP大、中剂量组,阳性对照组脑组织含水量显著降低(P<0.01);TwP各剂量组间结果亦有显著差异(P<0.01或P<0.05)。结论:TwP能减轻大鼠急性脑缺血再灌注损伤引起的脑水肿、降低脑组织丙二醛含量,提高SOD活性,降低细胞内钙积累;且随着剂量增加,变化显著增强,提示雷公藤多苷对大鼠急性脑缺血再灌注损伤具有保护作用。     

依托咪酯对神经元缺氧损伤的保护及其作用机制

目的观察依托咪酯对大鼠海马神经元缺氧损伤的保护作用及其机制。方法用原代培养的新生大鼠海马神经细胞建立缺氧模型,用MTT法测定神经元存活率。采用激光扫描共聚焦显微镜动态监测单个海马神经元[Ca2+]i随缺氧或加入谷氨酸、KC l前后的实时变化。结果依托咪酯在1.2~4.8 mg.L-1范围内,可剂量依赖性地降低神经元缺氧损伤时的细胞死亡率(P<0.05)。0.3~4.8 mg.L-1依托咪酯能抑制缺氧及50 mmol.L-1KC l引起的[Ca2+]i升高(P<0.05),仅在4.8 mg.L-1时才抑制1 mmo.lL-1谷氨酸所致的[Ca2+]i升高(P<0.01)。结论依托咪酯对离体大鼠海马神经元缺氧性损伤具有保护作用,其机制可能与依托咪酯抑制缺氧引起[Ca2+]i异常升高有关。     

microRNA-421-3p prevents inflammatory response in cerebral ischemia/reperfusion injury through targeting m6A Reader YTHDF1 to inhibit p65 mRNA translation

ObjectiveIschemic stroke is one of the leading causes of death globally, and inflammation is considered as a vital contributor to the pathophysiology of ischemic stroke. Recently, microRNA-421-3p-derived macrophages is found to promote motor function recovery in spinal cord injury. Here, we explored whether microRNA-421-3p is involved in inflammation responses during cerebral ischemia/reperfusion (I/R) injury and its molecular mechanism.MethodsAn in vivo experimental animal model of intraluminal middle cerebral artery occlusion/reperfusion (MCAO/R) and in vitro model of microglial subjected to oxygen-glucose deprivation and reoxygenation (OGD/R) were used. The effects of microRNA-421-3p on cerebral I/R injury and its underlying mechanism were detected by quantitative real-time PCR, western blotting, immunofluorescence staining, RNA immunoprecipitation, flow cytometry, luciferase reporter assay, and bioinformatics analysis.ResultsWe find that microRNA-421-3p is significantly decreased in cerebral I/R injury in vitro and in vivo. Furthermore, overexpression of microRNA-421-3p evidently suppresses pro-inflammatory factor expressions and inhibits NF-κB p65 protein expression and nuclear translocation in BV2 microglia cells treated with OGD/R. However, microRNA-421-3p neither promotes p65 mRNA expression, nor affects p65 mRNA or protein stability. Moreover, we find the m6A ‘reader’ protein YTH domain family protein 1 (YTHDF1) is the specific target of microRNA-421-3p, and YTHDF1 specifically binds to the m6a site of p65 mRNA to promote its translation.ConclusionmicroRNA-421-3p prevents inflammatory response in cerebral ischemia/reperfusion injury through targeting YTHDF1 to inhibit p65 mRNA translation. These findings provide novel insights into understanding the molecular pathogenesis of cerebral I/R injury.