模拟海拔8000m高原缺氧环境对大鼠脑组织线粒体自噬的影响

目的：研究大型低压氧舱模拟海拔8000 m 高原缺氧环境对大鼠线粒体自噬的影响。方法取30只Wistar 大鼠,随机分为正常、缺氧6 h、12 h、24 h 和48 h 组,每组6只,在大型低压氧舱中模拟海拔8000 m 高原缺氧环境,采集实验大鼠的脑组织进行电镜观察并对线粒体自噬蛋白微管相关蛋白1轻链3（LC3）、Beclin1以及凋亡相关蛋白细胞色素 C（CytC）、Caspase3、Bcl-2相关 X 蛋白（Bax）进行测定。结果电镜结果显示,不同时间缺氧组与正常组相比较,大鼠脑组织空泡增多,细胞间隙增大,细胞膜部分破碎,细胞受损,并且不同缺氧时间自噬发生程度较正常组均增多,缺氧24 h 组自噬程度最强,自噬体数量最多。各缺氧组凋亡相关蛋白 CytC、Caspase3和 Bax 表达水平随着缺氧时间的延长均上调,缺氧24 h 和48 h 组显著高于正常组（ P ﹤0.01）。自噬相关蛋白 LC3和 Beclin1表达随着缺氧时间增加呈现从升高到下降的趋势,其中 LC3在缺氧24 h 组表达程度最高（P ﹤0.05）,Beclin1蛋白在缺氧6 h 组表达升高,缺氧12 h 组表达最高（P ﹤0.01）。结论模拟海拔8000 m 缺氧环境会对大鼠造成损伤,促进凋亡相关蛋白的表达,同时促进了大鼠脑组织线粒体自噬的发生。     

土槿乙酸诱导的卵巢癌细胞HO-8910自噬及其机制

目的探讨土槿乙酸诱导的人卵巢癌细胞系HO-8910细胞自噬蛋白的表达及PI3K/Akt信号转导通路的变化,以及自噬特异性抑制剂3-甲基腺嘌呤(3-MA)和自噬激动剂雷帕霉素(RAPA)对自噬相关蛋白的影响。方法不同浓度的土槿乙酸作用HO-8910细胞,采用台盼蓝染色检测细胞的存活率,Western blot分析检测自噬相关蛋白及PI3K/Akt通路相关蛋白的变化,分别用3-MA和RAPA处理HO-8910细胞后检测自噬相关蛋白的变化。结果土槿乙酸能够诱导卵巢癌细胞HO-8910自噬,增加LC3-Ⅱ和自噬调节因子Beclin-1的表达;3-MA可以抑制土槿乙酸诱导的HO-8910细胞自噬相关蛋白的表达,而RAPA促进了土槿乙酸诱导的HO-8910细胞自噬相关蛋白的表达,且土槿乙酸能抑制PI3K/Akt通路蛋白的表达。结论土槿乙酸可通过抑制PI3K/Akt通路诱导HO-8910细胞自噬。     

钙络合剂BAPTA-AM对胞外酸化诱导大鼠关节软骨细胞自噬作用的影响及其可能机制

目的观察BAPTA-AM对胞外酸化诱导大鼠关节软骨细胞自噬作用的影响,探讨其可能的作用机制。方法体外使用胰酶-Ⅱ型胶原酶消化法分离提取大鼠关节软骨细胞,分为正常组(p H 7.4)、酸化组(p H 6.0)、以及分别经BAPTA-AM处理的正常组和酸化组,激光共聚焦技术检测软骨细胞胞内钙离子变化,实时荧光定量PCR法检测细胞自噬基因Beclin-1、ULK1 mRNA的表达,Western blot法检测自噬蛋白LC3的表达,吖啶橙染色分析细胞自噬溶酶体形成情况。结果与p H 7.4正常组比较,p H 6.0酸化刺激明显增加大鼠关节软骨细胞内Ca2+的浓度,且自噬标志物Beclin-1、ULK1 mRNA及LC3Ⅱ蛋白表达均明显升高,酸性自噬溶酶体形成增多,同时酸化刺激能引起Ca MKKβ及pAMPK蛋白表达水平增高,磷酸化蛋白p-m TOR水平明显降低。BAPTA-AM酸化组自噬水平和Ca MKKβ及p-AMPK表达明显降低,p-m TOR表达明显升高。结论 BAPTA-AM能明显减弱胞外酸化诱导软骨细胞自噬作用,其机制可能与抑制胞内Ca2+有关。     

九龙藤总黄酮调控自噬对抗心肌缺血/再灌注损伤的实验研究

目的研究九龙藤总黄酮(Bauhinia championii flavones,BCF)调控自噬抗心肌缺血/再灌注损伤的作用。方法120只SD大鼠随机分为假手术组、模型组、BCF高剂量组、BCF低剂量组、自噬抑制剂(3-MA)组(n=8),采用左冠状动脉前降支结扎法制备大鼠心肌缺血/再灌注模型,以紫外分光光度法检测缺血30min、缺血/再灌注1 h及3 h时肌酸激酶同工酶(CK-MB)、诱导型一氧化氮合酶(i NOS)、总抗氧化力(T-AOC)的含量;以Western blot法检测心肌微管相关蛋白轻链3蛋白-Ⅱ(LC3-Ⅱ)、Beclin-1、雷帕霉素靶蛋白(mammalian target of rapamycin,m TOR)的表达。结果与模型组相比,BCF能剂量依赖性提高心肌缺血/再灌注不同时段的T-AOC,降低CK-MB及i NOS含量,下调LC3-Ⅱ、Beclin-1蛋白表达,上调m TOR蛋白表达(P<0.05或P<0.01);与3-MA组相比,BCF能够降低i NOS及CK-MB,提高TAOC水平,缺血期上调LC3-Ⅱ、Beclin-1蛋白表达,再灌注期下调LC3-Ⅱ、Beclin-1蛋白表达,缺血/再灌注期均下调m TOR蛋白表达(P<0.05)。结论自噬在心肌缺血期即发生,并随着缺血/再灌注时间延长而进一步加强;BCF预处理可促进缺血期自噬发生及抑制再灌注时自噬过表达,从而减轻心肌缺血/再灌注损伤。     

表没食子儿茶素没食子酸酯调控自噬抗心肌缺血再灌注损伤

目的研究表没食子儿茶素没食子酸酯(EGCG)调控自噬抗心肌缺血再灌注损伤的作用。方法64只SD大鼠随机分为假手术、模型、3-甲基腺嘌呤(3-MA,15 mg·kg-1)、EGCG(20 mg·kg-1)四组(n=8),各组于造模前20 min舌下静脉给予相应试剂,采用左冠状动脉前降支结扎法制备大鼠心肌缺血再灌注模型,按试剂盒说明书检测缺血30 min及缺血30 min-再灌注1 h各组肌酸激酶同工酶(CK-MB)、总抗氧化力(T-AOC)、诱导型一氧化氮合酶(i NOS)的含量,以Western-blot法检测心肌微管相关蛋白轻链3蛋白-Ⅱ(LC3-Ⅱ)、Beclin-1、雷帕霉素靶蛋白(m TOR)的表达。结果自噬在心肌缺血期即发生,再灌注时进一步加强;与模型组相比,EGCG组心肌缺血-再灌注不同时段的T-AOC能有效提高,CK-MB及i NOS的含量降低,LC3-Ⅱ、Beclin-1蛋白表达下调,m TOR蛋白表达上调(P<0.05);与3-MA组相比,EGCG组大鼠血清i NOS及CK-MB降低,T-AOC含量提高,LC3-Ⅱ、Beclin-1蛋白表达下调,m TOR蛋白量上调(P<0.05)。结论 EGCG对心肌的保护作用可能与提高抗氧化力,降低i NOS有关;EGCG预处理可能通过短暂诱导心肌缺血期自噬发生,抑制再灌注时段自噬过度表达而减轻心肌缺血再灌注损伤。     

下调 HER2 降低自噬活性抑制人肺癌细胞增殖 转移作用的体外研究

目的 探讨下调 HER2 表达是否抑制细胞自噬活性, 从而影响人肺癌细胞的增殖、 迁徙和侵袭。方法 采用浓度 5 μmol/L 自噬抑制剂 3-MA、 10 μmol/L HER2 抑制剂 Neratinib 分别作用人肺癌细胞 A549。Western blot 检测肺癌细胞 A549 中 HER2、 Beclin-1 及 LC3B （Ⅱ/Ⅰ） 蛋白表达水平; Wound healing 和 Transwell invasion 实验检测 细胞迁徙、 侵袭能力; 四甲基偶氮唑盐 （MTT） 检测细胞的增殖能力。结果 Neratinib 和自噬抑制剂 （3-MA） 作用 24 h 后, 细胞 HER2、 Beclin-1 及 LC3B（Ⅱ/Ⅰ）蛋白表达水平显著低于阴性对照组; Neratinib、 自噬抑制剂（3-MA）处理组 的细胞增殖、 迁徙和侵袭能力显著低于阴性对照细胞。结论 下调 HER2 能降低人肺癌细胞 A549 的自噬活性并抑 制其增殖、 迁徙和侵袭     

番茄红素对心肌细胞缺氧损伤的作用机制

目的探讨番茄红素对心肌细胞沉默信息调节因子1（Sirtl）-自噬通路的作用。方法原代培养乳鼠心肌细胞予以无血清、无糖培养及缺氧干预,模拟心肌缺血,用番茄红素和Sirtl的抑制剂尼克酰胺干预。采用Westernblot法检测Sirtl、自噬相关基因6（Atg6）Beclinl及自噬相关基因8LC3蛋白的表达;RT—PCR技术检测心肌细胞Sirtl的mRNA表达。结果①在心肌缺氧中,番茄红素提高了细胞Sirtl蛋白和mRNA的表达水平;②番茄红素增加了心肌缺氧时自噬相关基因Beelinl和LC3蛋白的表达;③Sirtl的抑制剂尼克酰胺阻断了番茄红素对白噬蛋白的作用。结论番茄红素可能通过Sirtl激活自噬,从而减少心肌缺氧损伤。     

胰高血糖素样肽-1对AGEs诱导H9C2心肌细胞自噬的影响

目的观察胰高血糖素样肽-1(GLP-1)对晚期糖基化终产物(AGEs)诱导H9C2心肌细胞自噬(Autophagy)的影响,初步探讨GLP-1心肌细胞保护作用与自噬活性关系。方法将传代培养H9C2心肌细胞随机分4组:(1)Control组:加入0.9%生理盐水;(2)AGEs组:加入100 mg·L~(-1)AGEs;(3)AGEs+GLP-1组:同时加入100 mg·L~(-1)AGEs和10 nmol·L~(-1)GLP-1;(4)AGEs+GLP-1+Rapamycin组:同时加入100 mg·L~(-1)AGEs、10 nmol·L~(-1)GLP-1及5μmol·L~(-1)Rapamycin(自噬诱导剂)。各组在经上述预处理24 h后,分别用CCK-8法检测细胞存活率Hoechst 33258试剂盒检测细胞的凋亡率,DCFH-DA荧光探针检测细胞内活性氧(ROS)水平,流式细胞术检测细胞自噬溶酶体形成,Western blot法检测自噬相关蛋白(LC3Ⅱ,Beclin-1)表达。结果 (1)与Control组相比,AGEs组细胞生存率明显减少,细胞内ROS水平明显增高,细胞自噬溶酶体水平及自噬相关蛋白(LC3Ⅱ、Beclin-1)表达均明显增加;(2)与AGEs组相比,AGEs+GLP-1组细胞生存率明显增高,细胞内ROS水平、细胞自噬溶酶体水平及自噬相关蛋白(LC3Ⅱ、Beclin-1)表达均明显下降;(3)与AGEs组相比,AGEs+GLP-1+rapamycin组中细胞内ROS水平降低,而细胞生存率、细胞自噬溶酶体水平及自噬相关蛋白(LC3Ⅱ、Beclin-1)表达未见差异。结论 (1)AGEs可导致H9C2心肌细胞内ROS升高,诱导细胞损伤并激活细胞自噬;(2)GLP-1对AGEs诱导的H9C2心肌细胞损伤具有保护作用,其保护机制可能与抑制细胞自噬活性有关。     

基于NLRP3-IL-1β-NF-κB信号轴研究野菊花总黄酮对 脂多糖诱导HK-2细胞炎性反应及自噬的影响

摘要：目的 探究野菊花总黄酮（TFC）对脂多糖（LPS）诱导HK-2细胞炎性反应及自噬的影响,并初步探究其可 能的作用机制。方法 体外培养人肾小管上皮HK-2细胞,将细胞分为阴性对照（Control）组、LPS处理（LPS）组、TFC 预处理（TFC）组、NLRP3激活预处理（4-MET）组、TFC联合4-MET预处理（TFC+4-MET）组。CCK-8法检测细胞增殖 情况;Hoechst 33342染色观察各组细胞形态变化;免疫印迹法检测各组细胞核苷酸结合域样受体蛋白3（NLRP3）、凋 亡相关斑点样蛋白（Asc）、半胱氨酸天冬氨酸蛋白酶1（caspase-1）、p-IκB、IκB、自噬相关蛋白（Beclin1）、微管相关蛋 白轻链3Ⅱ（LC3Ⅱ）、LC3Ⅰ、蛋白表达情况;ELISA法检测细胞中白细胞介素（IL）-1β、IL-18水平;透射电镜观察细胞 自噬情况。结果 与Control组相比,LPS组细胞增殖率降低,细胞核破碎情况加重,细胞凋亡率升高,NLRP3、Asc、 caspase-1蛋白表达升高、IκB蛋白磷酸化水平升高,IL-1β、IL-18水平升高,LC3Ⅱ/Ⅰ水平、Beclin-1蛋白表达降低 （P＜0.05）。与LPS组相比,TFC组细胞增殖率升高,细胞核破碎减轻,细胞凋亡率降低,NLRP3、Asc、caspase-1蛋白 表达降低、IκB蛋白磷酸化水平降低,IL-1β、IL-18水平降低,细胞自噬程度增加,LC3Ⅱ/Ⅰ水平、Beclin-1蛋白表达升 高;4-MET组细胞增殖率降低,细胞凋亡率升高,细胞核破碎情况加重,NLRP3、Asc、caspase-1蛋白表达升高、IκB蛋 白磷酸化水平升高,IL-1β、IL-18水平升高,细胞自噬程度降低,LC3Ⅱ/Ⅰ水平、Beclin-1蛋白表达降低（P＜0.05）。 TFC+4-MET组细胞增殖率、细胞自噬程度、LC3Ⅱ/Ⅰ水平、Beclin-1蛋白表达高于4-MET组,细胞核破碎情况减轻, 细胞凋亡率、NLRP3、Asc、caspase-1蛋白表达、IκB蛋白磷酸化、IL-1β、IL-18水平低于4-MET组（P＜0.05）。结论 野菊花总黄酮可能通过抑制NLRP3-IL-1β-NF-κB信号通路活化,进而抑制脂多糖诱导HK-2细胞炎性反应,诱导 细胞自噬     

二氢杨梅素通过上调自噬活性抑制MPP~+诱导的PC12细胞损伤

目的观察二氢杨梅素(DMY)对1-甲基-4-苯基吡啶离子(MPP+)诱导的PC12细胞损伤的影响并探讨其可能的机制。方法含DMY 5,10,20,40和80μmol·L~(-1)的培养液预处理PC12细胞0.5 h,培养液中加入自噬抑制剂3-甲基腺嘌呤(3-MA)10 mmol·L~(-1),再加入MPP+500μmol·L~(-1)培养48 h。噻唑蓝(MTT)法检测细胞存活,丙酮酸二硝基苯腙比色法检测细胞培养液中乳酸脱氢酶(LDH)水平,透射电镜观察细胞的超微结构,Western蛋白质印迹法检测细胞中自噬相关蛋白Beclin-1和微管相关蛋白1轻链3(LC3)和P62的表达。结果与细胞对照组比较,MPP+组细胞存活率显著降低(P<0.05),细胞培养液中LDH水平显著增加(P<0.05),细胞中自噬体的数量明显减少,自噬泡占胞质总面积的百分率显著降低(P<0.05),LC3-Ⅱ和Beclin-1的蛋白表达及LC3-Ⅱ/LC3-Ⅰ的比值均显著降低(均P<0.05),P62的表达显著升高(P<0.05)。与MPP+组比较,MPP++DMY 10~80μmol·L~(-1)组细胞存活率显著升高(P<0.05),细胞培养液中LDH水平显著降低(P<0.05)。与MPP+组比较,MPP++DMY 20μmol·L~(-1)组细胞中自噬体数量明显增加,自噬泡占胞质总面积的百分率显著增加(P<0.05),LC3-Ⅱ和Beclin-1的蛋白表达和LC3-Ⅱ/LC3-Ⅰ的比值均显著增加(P<0.05),P62的表达显著降低(P<0.05)。与MPP++DMY 20μmol·L~(-1)组比较,MPP++DMY+3-MA组细胞存活率显著降低(P<0.05),细胞上清液中LDH水平显著增加(P<0.05)。结论 DMY抑制MPP+诱导的PC12细胞损伤,其机制与上调细胞自噬活性有关。     

Mechanistic target of rapamycin-mediated autophagy is involved in the alleviation of lipopolysaccharide-induced acute lung injury in rats

Acute lung injury (ALI) is a complex clinical syndrome with high morbidity and mortality rates. Autophagy is an adaptive process that plays a complex role in ALI. The aim of this study was to investigate the effects of autophagy on lipopolysaccharide (LPS)-induced lung injury by establishing a rat ALI model and to further explore the possible mechanisms involved. Rats were pretreated with the autophagy inhibitor 3-methyladenine (3-MA) or the autophagy activator rapamycin before they were challenged with the intratracheal instillation of LPS (5 mg/kg). The level of autophagy in the lung tissue was detected. Lung injury and vascular permeability were assessed. The role of the mechanistic target of rapamycin (mTOR)-mediated Unc-51-like kinase 1 (ULK1) and the class III PI3 kinase VPS34 in autophagy regulation was examined. LPS challenge induced autophagy and rapamycin pretreatment enhanced autophagy activity in LPS-induced ALI rats. LPS caused severe lung injury and high pulmonary vascular permeability, which could be alleviated by enhancing autophagy. In addition, the inhibition of mTOR upregulated the expression of ULK1 and VPS34 and thus increased LPS-induced autophagy. Autophagy plays a protective role in LPS-induced ALI, and enhancing autophagy via the inhibition of mTOR alleviates lung injury and pulmonary barrier function. Moreover, mTOR negatively mediates ULK1 and VPS34 to regulate LPS-induced autophagy in rats.     

Aluminum maltolate induces primary rat astrocyte apoptosis via overactivation of the class III PI3K/Beclin 1-dependent autophagy signal

Aluminum-induced neuronal cell apoptosis has been implicated in various neurodegenerative disorders. However, whether autophagy, a vital lysosomal degradation pathway, is involved in this pathogenesis still remains unknown. Our present findings demonstrated that aluminum significantly increased rat astrocyte apoptosis and autophagy levels in a dose-dependent manner. Examination of the associated mechanisms revealed that aluminum at low levels (400μM) did not increase apoptosis protein expressions (cleaved caspase-3 and cleaved PARP), but markedly up-regulated autophagy-related protein Beclin 1 expression. This indicates that the autophagy process occurs earlier than neuronal apoptosis. Moreover, aluminum at high levels (1600μM) significantly induced autophagy-related protein (Beclin 1 and LC3II) and apoptosis-related protein expressions, showing that both autophagy and apoptosis processes are activated under high levels of aluminum exposure. We used 3-methyladenine, an inhibitor of class III phosphatidylinositol-3 kinase, to treat astrocytes and found that the apoptosis rate in the 3-MA/aluminum co-treated group was markedly down-regulated compared with aluminum alone-treated astrocytes. The apoptosis protein and autophagy-related protein expressions were also decreased. These observations showed that the mild autophagy process may precede apoptosis in low dose aluminum-insulted astrocytes, and high dose aluminum-induced serious autophagy may result in cell apoptosis via the Beclin 1-dependent autophagy signal pathway.     

Enhancement of epithelial cell autophagy induced by sinensetin alleviates epithelial barrier dysfunction in colitis

OBJECTIVE Intestinal epithelial barrier dysfunction is a key pathology of colitis. Autophagy of epithelial cells maintains homeostasis of the intestinal barrier by inhibiting apoptosis and stimulating degradation of the tight junction protein claudin-2. METHODS This study investigated the effects and mechanism of activity of sinensetin, a polymethylated flavonoid isolated from tangerine peel and citrus, on intestinal barrier dysfunction in colitis. Animal model of colitis were established by intracolonic administration of 2, 4, 6-trinitrobenzene sulfonic acid and oral treatment with dextran sulfate sodium. Epithelial barrier function was evaluated by measuring the serum recovery of fluorescein isothiocyanate-4 k D dextran in vivo and transepithelial electrical resistance in Caco-2 cells, respectively. Epithelial cell autophagy assayed by autophagosome formation and expression of autophagy-related protein. RESULTS Sinensetin reversed colitis-associated increase in intestinal permeability, significantly promoted epithelial cell autophagy,and further decreased epithelial cel apoptosis, and reduced mucosal claudin-2. Sinenstetin alleviated colitis symptoms rats and mice with colitis. Knockdown of 5′ adenosine monophosphate-activated protein kinase(AMPK) reversed the promotion of epithelial autophagy by sinensetin.CONCLUSION Sinensetin significantly alleviated intestinal barrier dysfunction in colitis by promoting epithelial cell autophagy, and further inhibiting apoptosis and promoting claudin-2 degradation. The results highlighted novel potential benefits of sinensetin in colitis.     

Nod1受体激活对腹膜间皮细胞自噬相关蛋白表达的影响

目的探讨Nod1受体激活对腹膜间皮细胞自噬的影响。方法 Nod1受体激动剂iE-DAP作用大鼠原代培养腹膜间皮细胞0、1、2h,Western blot检测微管相关蛋白1轻链3(LC3)、Beclin-1的表达。结果随刺激时间延长,LC3-Ⅱ/LC3-Ⅰ蛋白表达比值增加,Beclin-1蛋白表达亦增加。结论 Nod1受体激活可诱导腹膜间皮细胞自噬的发生,这有可能发挥清除细胞内细菌感染的作用。     

Beclin-1与Bcl-2在血管性痴呆大鼠海马CA1区的表达及意义

【摘要】目的观察自噬相关蛋白Beclin-1与凋亡相关蛋白Bcl-2在血管性痴呆大鼠海马CA1区的表达及变化情况。方法60只实验大鼠随机分为假手术组和血管性痴呆模型组（模型组）,每组又随机分为模型制备成功后1、2、4、8和12周5个亚组（各6只）。采用四血管阻断法制备血管性痴呆模型,Morris水迷宫法测试学习记忆能力,免疫组化法检测自噬相关蛋白Beclin-1及凋亡相关蛋白Bcl-2的表达。结果模型组大鼠海马CA1区1周时可见Be clin-1、Bcl-2蛋白阳性表达,4 周达到高峰,8周开始下降,至12 周仍较高。与假手术组比较,模型组各时间点的Be clin-1、Bcl-2蛋白表达均明显增高,差异均有统计学意义（P < 0.05或P < 0.01）。模型组大鼠海马CA1区的Beclin-1阳性表达数与Bcl-2阳性表达数呈正相关（r=0.809,P < 0.05）。结论血管性痴呆大鼠海马CA1区自噬和凋亡同时发生,且表达趋势一致。     

低氧微环境下自噬对顺铂处理的肺腺癌A549细胞增殖活性的影响

目的观察在低氧环境下自噬对人肺腺癌A549细胞化疗敏感性的影响。方法常规低氧培养人肺腺癌A549细胞,分为低氧对照组及低氧＋3-甲基腺嘌呤（3-MA）组,分别采用透视电子显微镜观察不同时间点细胞自噬体的变化,Western blot检测自噬标记蛋白微管相关蛋白1轻链3（LC3）蛋白表达,分析LC3II/LC3I比值变化。随后每组再给予顺铂（DDP）处理后,采用MTT比色法检测细胞增殖活性。结果低氧状态下,A549细胞自噬体形成增加,LC3II/LC3I蛋白比值表达升高,加入自噬抑制剂3-MA后,自噬体数量、LCII/LCI比值较单纯低氧组均下降。予顺铂处理后,低氧＋3-MA组细胞增殖活性较低氧组下降。结论在低氧环境中,A549细胞保护性自噬增强,抑制自噬可增强A549细胞对顺铂化疗的敏感性。     

Oridonin induced autophagy in human cervical carcinoma HeLa cells through Ras, JNK, and P38 regulation

In this study, we investigated autophagy induced by oridonin in HeLa cells. HeLa cells were exposed to oridonin, and the fluorescent changes, autophagic levels, and protein expressions were evaluated. Oridonin induced autophagy in HeLa cells in vitro in a dose- and time-dependent manner. Oridonin-treated HeLa cells, which had been prelabeled with the autophagosome-specific dye monodansylcadervarine (MDC), recruited more MDC-positive particles and had a significantly higher fluorescent density; and simultaneously, expressions of autophagy-related proteins, MAP-LC3 and Beclin 1, were increased by oridonin. In oridonin-induced Hela cells, pretreatment with 3-methyladenine (3-MA, the specific inhibitor of autophagy) dose-dependently decreased the autophagic ratio accompanied with downregulation of the protein expressions of MAP-LC3 and Beclin 1. Furthermore, when a Ras inhibitor was applied, the autophagic levels were augmented, whereas P38 and JNK inhibitors decreased the autophagic ratio significantly, indicating that this oridonin-induced autophagic process was negatively regulated by Ras, but positively regulated by P38 and JNK MAPKs. Raf-1 and ERK1/2 had no obvious correlation to these signaling pathways.     

Geniposide inhibits NLRP3 inflammasome activation via autophagy in BV-2 microglial cells exposed to oxygen–glucose deprivation/reoxygenation

The nod-like receptor protein 3 (NLRP3) inflammasome has a critical role in cerebral ischemia. Autophagy may cause microglial inflammatory response or stimulate microglial function. The evidences clarify a direct crosstalk between autophagy and NLRP3. Geniposide could protect neurons or PC-12 cells against cerebral ischemic injury. However, a detailed understanding of molecular mechanisms on geniposide is still unclear. This study aimed to evaluate whether geniposide could inhibit the expression and activation of NLRP3 inflammasome in BV-2 microglial cells following oxygen–glucose deprivation/reoxygenation (OGD/R) and assessed whether autophagy is involved in this process. We used OGD/R model in BV2 microglial cells in order to mimic the ischemic reperfusion injury. The NLRP3 shRNA and autophagy inhibitor (3-MA) were used to suppress NLRP3 inflammation activation and autophagy. The results demonstrated geniposide decreased cell death and the levels of NLRP3, ASC, cleaved- caspase-1 and IL-1β, whereas significantly increased the conversion of LC3 and Beclin-1 expression, decreased the expression of P62. Taken together, our results suggested that the effect of geniposide could be ascribed to the reduction of the level of inflammatory cytokines via inhibiting the activation and expression of NLRP3 inflammasome and increasing autophagic activity following OGD/R in BV-2 microglial cells. We provided a new understanding of geniposide in neuroprotection by activating autophagy and promoting anti-inflammation inhibiting NLRP3 inflammasome in microglial cells. It might be helpful for geniposide on effective therapeutic strategies in ischemic stroke.