Ginkgo biloba extract protects against diabetic cardiomyopathy by restoring autophagy via adenosine monophosphate-activated protein kinase/mammalian target of the rapamycin pathway modulation

Studies demonstrated that Ginkgo biloba extract (GBE) played a cardioprotective role in diabetic conditions. Impaired autophagy is one of the mechanisms underlying diabetic cardiomyopathy (DCM). The effect of GBE on autophagy has been observed in several diseases; however, whether GBE can ameliorate DCM by regulating autophagy remains unclear. Here, we investigated the effect of GBE on DCM and the potential mechanisms regarding autophagy using a streptozotocin (STZ)-induced diabetic rat model and a high-glucose (HG)-stimulated H9C2 cell model. We demonstrated that GBE attenuated metabolic disturbances, improved cardiac function, and reduced myocardial pathological changes in diabetic rats. Impaired autophagy as well as dysregulation of the adenosine monophosphate-activated protein kinase/ mammalian target of the rapamycin (AMPK/mTOR) signaling pathway were observed in diabetic hearts, as evidenced by the reduced conversion of LC3B-I to LC3B-II along with excessive p62 accumulation, decreased AMPK phosphorylation, and increased mTOR phosphorylation, which could be reversed by GBE treatment. In vitro, GBE reduced the apoptosis induced by HG in H9C2 cells by activating AMPK and inhibiting mTOR to restore autophagy. However, this effect was inhibited by the AMPK inhibitor Compound C. In conclusion, the ameliorative effect of GBE on DCM might be dependent on the restoration of autophagy through modulation of the AMPK/mTOR pathway.     

Qili Qiangxin,a compound herbal medicine formula,alleviates hypoxia-reoxygenation-induced apoptotic and autophagic cell death via suppression of ROS/AMPK/mTOR pathway in vitro

ObjectiveQili Qiangxin (QLQX), a compound herbal medicine formula, is used effectively to treat congestive heart failure in China. However, the molecular mechanisms of the cardioprotective effect are still unclear. This study explores the cardioprotective effect and mechanism of QLQX using the hypoxia-reoxygenation (H/R)-induced myocardial injury model.MethodsThe main chemical constituents of QLQX were analyzed using high-performance liquid chromatography-evaporative light-scattering detection. The model of H/R-induced myocardial injury in H9c2 cells was developed to simulate myocardial ischemia–reperfusion injury. Apoptosis, autophagy, and generation of reactive oxygen species (ROS) were measured to assess the protective effect of QLQX. Proteins related to autophagy, apoptosis and signalling pathways were detected using Western blotting.ResultsApoptosis, autophagy and the excessive production of ROS induced by H/R were significantly reduced after treating the H9c2 cells with QLQX. QLQX treatment at concentrations of 50 and 250 μg/mL caused significant reduction in the levels of LC3II and p62 degradation (P < 0.05), and also suppressed the AMPK/mTOR signalling pathway. Furthermore, the AMPK inhibitor Compound C (at 0.5 μmol/L), and QLQX (250 μg/mL) significantly inhibited H/R-induced autophagy and apoptosis (P < 0.01), while AICAR (an AMPK activator, at 0.5 mmol/L) increased cardiomyocyte apoptosis and autophagy and abolished the anti-apoptotic effect of QLQX. Similar phenomena were also observed on the expressions of apoptotic and autophagic proteins, demonstrating that QLQX reduced the apoptosis and autophagy in the H/R-induced injury model via inhibiting the AMPK/mTOR pathway. Moreover, ROS scavenger, N-Acetyl-L-cysteine (NAC, at 2.5 mmol/L), significantly reduced H/R-triggered cell apoptosis and autophagy (P < 0.01). Meanwhile, NAC treatment down-regulated the ratio of phosphorylation of AMPK/AMPK (P < 0.01), which showed a similar effect to QLQX.ConclusionQLQX plays a cardioprotective role by alleviating apoptotic and autophagic cell death through inhibition of the ROS/AMPK/mTOR signalling pathway.     

活血消瘿方含药血清调控AMPK/mTOR通路对脂多糖诱导的甲状腺滤泡上皮细胞自噬和凋亡的影响

目的 探讨活血消瘿方含药血清对脂多糖(LPS)诱导的甲状腺滤泡上皮细胞(TFECs)自噬和凋亡的影响以及作用机制。方法 光学显微镜观察分离培养的SD大鼠TFECs细胞的形态;免疫荧光染色鉴定TFECs中特异抗原甲状腺球蛋白(Tg)。取对数生长期的TFECs,分为对照组、LPS组、含药血清组、含药血清+compound C(AMPK抑制剂)组、含药血清+MHY1485(mTOR激活剂)组,MTT法检测各组细胞活力;绿色荧光蛋白(GFP)标记质粒转染检测各组细胞自噬小体变化;流式细胞术检测各组细胞凋亡;western blot检测各组细胞中微管相关蛋白1轻链3(LC3)I、LC3II、Beclin1、Bcl-2相关X蛋白(Bax)、B淋巴细胞瘤-2(Bcl-2)及AMP活化蛋白激酶(AMPK)/哺乳动物雷帕霉素靶蛋白(mTOR)通路相关蛋白表达。结果 光学显微镜观察显示,TFECs形态为梭形、形态均一,且可成簇生长。免疫荧光结果显示,TFECs细胞质中可见较强的Tg荧光染色。与对照组比较,LPS组TFECs细胞活力、自噬小体数量、LC3II/LC3I、Beclin1、Bcl-2、p-AMPK/AMPK蛋白相对表达量显著降低,炎性因子IL-6 、TNF-α水平、细胞凋亡率、Bax、p-mTOR/mTOR蛋白相对表达量显著升高(P< 0.05);与LPS组比较,含药血清组TFECs细胞活力、自噬小体数量、LC3II/LC3I、Beclin1、Bcl-2、p-AMPK/AMPK蛋白相对表达量显著升高,炎性因子IL-6 、 TNF-α水平、细胞凋亡率、Bax、p-mTOR/mTOR蛋白相对表达量显著降低(P< 0.05);与含药血清组比较,含药血清+compound C组、含药血清+MHY1485组TFECs中相应指标与上述趋势相反。结论 活血消瘿方含药血清对LPS诱导的TFECs自噬的促进作用及细胞凋亡的抑制作用可能与激活AMPK/mTOR通路有关。     

大黄酸调控mTOR信号通路活性抑制肾小管上皮细胞自噬蛋白表达的分子机制

目的:探讨大黄酸抑制饥饿诱导的肾小管上皮(NRK-52E)细胞自噬蛋白的作用和分子机制。方法:用Hank’s平衡盐溶液(Hank’s balanced salt solution,HBSS)诱导NRK-52E细胞产生饥饿状态,在干预后的各时间点(0,0.5,1,2,6 h),首先,检测细胞自噬标志性蛋白——哺乳动物同族物微管相关蛋白1轻链3(microtubule-associated protein 1 light chain 3,LC3)I/II的表达水平;其次,检测细胞哺乳动物类雷帕霉素靶蛋白(mammalian target of rapamycin,m TOR)表达及其磷酸化水平(phosphorylated-m TOR Ser2448,p-m TOR S2448);然后,以大黄酸(5 mg·L-1)、HBSS(1 m L)以及m TOR抑制剂雷帕霉素(100 nmol·L-1)单独或联合干预,分别检测其LC3 I/II,m TOR,p-m TOR S2448蛋白表达水平的变化。结果:HBSS诱导NRK-52E细胞LC3II蛋白高表达、p-m TOR S2448蛋白低表达;大黄酸与HBSS联合干预可以逆转HBSS诱导的NRK-52E细胞LC3 II和p-m TOR S2448蛋白表达水平;雷帕霉素与大黄酸、HBSS联合干预可以恢复HBSS诱导的NRK-52E细胞LC3 II蛋白表达水平。结论:HBSS抑制m TOR信号通路活性而诱导肾小管上皮细胞发生自噬;大黄酸调控m TOR信号通路活性而抑制肾小管上皮细胞自噬蛋白的表达,这可能就是其干预细胞自噬的作用和分子机制。     

迷迭香酸通过AMPK/mTOR通路减轻新生大鼠缺血缺氧性脑损伤研究

目的 探讨迷迭香酸对新生大鼠缺血缺氧脑损伤（hypoxic-ischemic encephalopathy,HIE）的影响,及其对单磷酸腺苷活化蛋白激酶（adenosine monophosphate activated protein kinase,AMPK）/雷帕霉素靶蛋白（mammalian target of rapamycin,mTOR）通路的调控作用,初步探讨其脑保护机制。方法 取7 d龄SD新生大鼠,随机分为对照组、模型组、迷迭香酸（300 mg/kg）组、AMPK/mTOR激动剂MT6378（10 mg/kg）组、AMPK抑制剂GSK-690693（30 mg/kg）组和迷迭香酸（300 mg/kg）+MT6378（10 mg/kg）组,每组20只。建立HIE模型,给予相应药物进行干预,采用TTC染色法检测大鼠脑梗死情况;透射电镜（TEM）观察大鼠海马神经元结构损伤及自噬状况;免疫荧光法检测大鼠海马神经元自噬标记物微管相关蛋白1轻链3B（microtubule-associated protein 1 light chain 3B,LC3B）阳性表达;TUNEL法检测大鼠海马神经元凋亡率;免疫组化法检测大鼠海马神经元磷酸化AMPK（p-AMPK）阳性表达;Western blotting检测大鼠海马组织活化的半胱氨酸蛋白酶3（cleaved Caspase-3）、mTOR及其磷酸化蛋白（p-mTOR）、Unc-51样自噬激活激酶1（uncoordinated-51 like autophagy activating kinase 1,Ulk1）及其磷酸化蛋白（p-Ulk1）、LC3B表达。结果 与对照组相比,模型组大鼠脑梗死严重,海马神经元结构损伤及自噬空泡形成较多,细胞自噬及凋亡水平升高,AMPK/mTOR通路活化（P<0.05）。与模型组相比,迷迭香酸组及GSK-690693组大鼠脑梗死、海马神经元结构损伤、凋亡及自噬减弱,AMPK/mTOR通路被抑制（P<0.05）;MT6378组海马组织AMPK/mTOR通路进一步激活,大鼠脑梗死、海马神经元结构损伤、凋亡及自噬进一步加重（P<0.05）;MT6378可逆转迷迭香酸的上述作用（P<0.05）。结论 迷迭香酸可能通过抑制AMPK/mTOR通路激活,降低海马神经元自噬及凋亡进程,发挥抗HIE脑损伤作用。     

肝豆汤对Wilson病模型高铜诱导的SH-SY5Y细胞自噬效应的影响及其作用机制

目的:研究肝豆汤对高铜诱导的人神经母细胞瘤(SH-SY5Y)细胞自噬效应的影响及其作用机制,为中医药防治脑型Wilson病(Wilson disease,WD)提供新的治疗靶点和研究思路。方法:噻唑蓝(MTT)比色法筛选硫酸铜(CuSO_4)造模浓度(0,100,200,400,800,1 600μmol·L-1)及时间; MTT比色法筛选含药血清浓度(5%,10%,15%,20%)及时间;乳酸脱氢酶(LDH)释放实验检测细胞LDH漏出率;流式细胞法检测细胞内活性氧(ROS)的含量;荧光染料JC-1检测细胞线粒体膜电位;流式细胞仪对自噬进行定量分析。蛋白免疫印迹法(Western blot)检测肝激酶B1(LKB1),腺苷酸活化蛋白激酶(AMPK),自噬微管相关蛋白轻链3A/B(LC3A/B),哺乳动物雷帕霉素靶蛋白(mTOR),unc-51样激酶1(ULK1),磷酸化ULK(p-ULK),磷酸化AMPK(p-AMPK)蛋白的表达。结果:MTT结果显示,CuSO_4对细胞的损伤呈现一定的量效和时效关系(P 0. 01),随着CuSO_4作用浓度及时间的增加,细胞存活率呈现下降趋势; 10%含肝豆汤兔血清可显著抑制CuSO_4诱导的细胞死亡(P 0. 01)。LDH释放实验显示,与正常组比较,CuSO_4作用细胞后LDH漏出率显著增加(P 0. 01),与模型组比较,含肝豆汤兔血清明显降低CuSO_4损伤细胞的LDH漏出率(P 0. 05)。DCFH-DA荧光染色显示,与正常组比较,CuSO_4可显著增加细胞内ROS生成(P 0. 01),与模型组比较,含肝豆汤兔血清可显著抑制CuSO_4诱导的细胞内ROS产生(P 0. 01)。JC-1染色结果显示,与正常组比较,CuSO_4诱导细胞线粒体膜电位Δψm显著降低(P 0. 01),与模型组比较,含肝豆汤兔血清明显抑制CuSO_4诱导的线粒体膜电位降低Δψm(P 0. 05)。Western blot结果显示,与正常组比较,模型组细胞内LKB1,AMPK,LC3A/B,ULK1及p-AMPK蛋白的表达显著增加,mTOR及p-ULK蛋白的表达显著降低(P 0. 01)。与模型组比较,含肝豆汤兔血清组LKB1,AMPK,LC3A/B,ULK1及p-AMPK蛋白表达显著降低,mTOR及p-ULK蛋白表达显著增加(P 0. 01)。结论:高铜可通过诱导细胞内线粒体氧化应激,上调自噬相关蛋白LKB1,p-AMPK,AMPK,LC3A/B及ULK1的表达,下调自噬相关蛋白mTOR及p-ULK的表达,导致细胞发生自噬性死亡,而肝豆汤可通过调控LKB1/AMPK信号通路,下调自噬相关蛋白LKB1,p-AMPK,LC3A/B,ULK及AMPK的表达,上调自噬相关蛋白及基因mTOR及p-ULK的表达,抑制自噬的发生,阻断高铜诱导的神经元损伤,从而发挥神经保护作用。     

丹参酮Ⅱa通过AMPK/mTOR通路调节自噬促进急性白血病细胞凋亡作用机制研究

目的观察丹参酮Ⅱa对HL-60的凋亡与自噬以及相关因子水平的影响,探讨丹参酮Ⅱa抗急性髓系白血病的分子机制。方法使用不同浓度的丹参酮Ⅱa处理HL-60细胞24、48 h后用CCK-8法检测增殖抑制率,吉姆萨染色观察细胞形态,Western blotting检测Caspase-3、Cleaved-Caspase-3、PARP-1、p-AMPK、pmTOR、LC3B水平变化,联用自噬抑制剂巴弗洛霉素A1以CCK-8测细胞存活率。结果以0、1、2、4、8、16、32、64、128μmol/L丹参酮Ⅱa处理HL-60细胞24、48 h后HL-60增殖被抑制,其作用随浓度增加和时间延长而加强,24、48 h的IC₅₀分别为32.87、18.4μmol/L;吉姆萨染色镜下观察见,随着药物浓度增加HL-60凋亡增加;Western blotting显示Caspase-3减少、Cleaved-Caspase-3增加,PARP-1切割增加,凋亡增强;p-AMPK增加、pmTOR减少、LC3B增加,显示AMPK/mTOR自噬通路激活,联用巴弗洛霉素A1后丹参酮Ⅱa增殖抑制作用减弱。结论丹参酮Ⅱa通过诱导HL-60凋亡和自噬发挥抗白血病作用,AMPK/mTOR可能是介导这一效应的重要信号通路。     

槲皮素对5-FU诱导的结直肠癌SW480细胞耐药及自噬调控机制研究

目的:探讨槲皮素(Que)调控5-氟尿嘧啶(5-FU)诱导的结直肠癌SW480细胞耐药及自噬的作用及机制。方法:采用浓度递增诱导法建立5-FU耐药细胞株SW480/5-FU,MTT法设置Que高、中、低剂量组(10、20、40 μmol/L)和对照组。MTT法检测各组细胞的5-FU耐药性,TUNEL染色法检测细胞凋亡,免疫荧光检测细胞自噬活性,Western blot检测细胞p糖蛋白(Pgp)、多药耐药相关蛋白1(MRP1)、三磷酸腺苷结合转运蛋白G超家族成员2抗体(ABCG2)、LC3Ⅰ、LC3Ⅱ、p62、丝/苏氨酸激酶(AKT)、p-AKT、雷帕霉素靶蛋白(mTOR)和p-mTOR蛋白表达。结果:5-FU抑制SW480/5-FU细胞的半抑制浓度(IC₅₀)明显高于SW480细胞(P<0.05),耐药指数(RI)=13.74。与对照组相比,Que中、高剂量组5-FU抑制SW480/5-FU细胞的IC₅₀明显下降(P<0.05),耐药逆转倍数分别为2.27和4.03。与对照组相比,Que中、高剂量组细胞抑制率、凋亡率和自噬活性明显升高(均P<0.05),蛋白的表达均明显升高(均P<0.05),P-gp、MRP1、ABCG2、p62、p-AKT/AKT和p-mTOR/mTOR蛋白表达明显下降(均P<0.05)。结论:Que可以以剂量依赖性的方式逆转SW480/5-FU细胞的5-FU耐药性,诱导细胞自噬,其作用机制可能与抑制AKT/mTOR的磷酸化有关。     

丹参酮ⅡA诱导白血病细胞凋亡过程中端粒酶活性的改变

目的观察丹参酮Ⅱ_A(TanⅡ_A)对HL60,K562细胞端粒酶活性的抑制作用和对凋亡相关基因的影响,探讨丹参酮Ⅱ_A对造血细胞的作用机理。方法以HL60,K562为靶细胞,应用细胞培养技术,流式细胞术,透射电镜观察TanⅡ_A对HL60,K562细胞的作用,利用PCRTRAP方法检测TanⅡ_A处理前后HL60,K562细胞端粒酶活性的改变。结果经05μg·mL^-1TanⅡ_A作用6d后,HL60,K562细胞生长明显受到抑制,生长抑制率分别为756%和563%。经丹参酮诱导后,HL60,K562细胞发生凋亡,出现亚二倍体峰;同时显著下调HL60及K562细胞的cmyc,bcl2基因表达,上调cfos基因表达。HL60,K562细胞在TanⅡ_A作用后,端粒酶活性受到抑制,端粒酶活性抑制率分别为308%,508%。结论TanⅡ_A可明显抑制HL60和K562细胞的增殖和细胞端粒酶活性,并诱导细胞凋亡。     

Thymoquinone attenuates hepatic lipid accumulation by inducing autophagy via AMPK/mTOR/ULK1-dependent pathway in nonalcoholic fatty liver disease

Thymoquinone (TQ) has been proved to exert wide-ranging pharmacological activities, with anti-inflammatory, antioxidant, anticonvulsant, antimicrobial, anti-tumor, and antidiabetic properties. In this study, we investigated the beneficial effects of TQ on a high-fat diet (HFD)-induced nonalcoholic fatty liver disease (NAFLD) in C57BL/6 N mice in vivo and free fatty acid (FFA)-induced human hepatocellular carcinoma HepG2 cells in vitro. Further, the underlying mechanisms of TQ to promote hepatic autophagy were also discovered. Data showed that TQ caused (p < 0.01) body weight reduction, improved glucose homeostasis, alleviated hepatosteatosis, and decreased hepatic lipid accumulation related to the induction of autophagy in HFD-fed mice. In vitro, TQ obviously increased (p < 0.01) autophagic flux in FFA-induced HepG2 cells and consequently reduced the lipid accumulation in combination with activation of AMPK/mTOR/ULK1 signaling pathways. Moreover, pharmacological inhibition of the AMPK pathway by addition with AMPK inhibitor Compound C (CC) or silence of ULK1 by transfection with siRNA(ULK1) into HepG2 cells reversed these beneficial effects of TQ on triggering hepatic autophagy and reducing lipid accumulation (p < 0.01). Taken together, these results suggested that TQ alleviated hepatic lipid accumulation by triggering autophagy through the AMPK/mTOR/ULK1-dependent signaling pathway. Our study supports a potential role for TQ in ameliorating NAFLD.     

大黄素诱导自噬改善顺铂导致肾小管细胞损伤机制探索

目的：观察大黄素对顺铂所致的肾小管上皮细胞（NRK-52E）损伤的影响,探讨其可能分子调节机制。方法：观察大黄素对顺铂所致NRK-52E细胞形态学改变的影响;采用Western Blot方法检测顺铂单独处理和加入大黄素共同处理细胞后,凋亡相关蛋白Caspase-3和cleaved Caspase-3的表达情况;用大黄素干预细胞不同的时间点,观察微管相关蛋白1轻链3（LC3）II/I的表达和pmRFP-LC3质粒转染细胞后荧光颗粒的变化情况,同时观察雷帕霉素处理细胞不同时间点后LC3-II/I的表达情况及其对顺铂环境下细胞形态学改变的影响,并观察大黄素对自噬上游通路AMPK的活化和mTOR信号的影响。结果：顺铂可以诱导NRK-52E细胞出现形态学改变,大黄素能够改善顺铂导致的变化。另外,大黄素干预可以下调顺铂导致的cleaved Caspase-3蛋白表达的增多;大黄素处理细胞不同时间点LC3-II/LC3-I的比值明显上升,pmRFP-LC3转染观察到大黄素处理细胞后自噬颗粒明显增多。同时雷帕霉素处理细胞后LC3-II/LC3-I的比值明显上升,其与顺铂共同干预能明显改善顺铂诱导的细胞凋亡;大黄素干预时间的延长,p-mTOR蛋白表达明显下调,p-AMPK的表达明显上调。结论：大黄素可以改善顺铂诱导的NRK-52E细胞凋亡,其作用机制可能是通过调节AMPK/mTOR信号通路诱导自噬来发挥肾保护作用。     

丹参酮IIA对肾癌786-O细胞生长抑制作用及其分子机制

目的 研究丹参酮IIA对肾癌细胞生长抑制作用及其分子机制.方法 MTT法检测丹参酮IIA对肾癌细胞活力影响;流式细胞分析检测丹参酮IIA对肾癌细胞周期阻滞;免疫印迹检测细胞周期阻滞相关靶蛋白蛋白表达水平;激光共聚焦观察核仁蛋白Nucleophosmin (NPM)/B23定位的变化.结果 丹参酮能够呈浓度依赖方式显著抑制肾癌细胞生长活力(P＜0.05);细胞周期分析表明丹参酮IIA处理的肾癌细胞阻滞在S期;免疫印迹结果证明丹参酮IIA处理肾癌细胞,cyclin A,p53及其下游基因p21显著上调;激光共聚焦结果表明在丹参酮IIA作用下,NPM蛋白定位从核仁移位到核浆.结论 丹参酮IIA作用786-O细胞导致细胞周期S阻滞,其机制可能与NPM移位促使其相互作用靶蛋白p53和p21蛋白水平上调有关.     

Activation of AMP‐activated Protein Kinase and Phosphorylation of Glycogen Synthase Kinase3 β Mediate Ursolic Acid Induced Apoptosis in HepG2 Liver Cancer Cells

Despite the antitumour effect of ursolic acid observed in several cancers, the underlying mechanism remains unclear. Thus, in the present study, the roles of AMP‐activated protein kinase (AMPK) and glycogen synthase kinase 3 beta (GSK3β) were examined in ursolic acid induced apoptosis in HepG2 hepatocellular carcinoma cells. Ursolic acid significantly exerted cytotoxicity, increased the sub‐G1 population and the number of ethidium homodimer and terminal deoxynucleotidyl transferase(TdT) mediated dUTP nick end labeling positive cells in HepG2 cells. Also, ursolic acid enhanced the cleavages of poly‐ADP‐ribose polymerase (PARP) and caspase3, attenuated the expression of astrocyte elevated gene (AEG1) and survivin in HepG2 cells. Interestingly, ursolic acid increased the phosphorylation of AMPK and coenzyme A carboxylase and also enhanced phosphorylation of GSK3β at inactive form serine 9, whereas ursolic acid attenuated the phosphorylation of AKT and mTOR in HepG2 cells. Conversely, AMPK inhibitor compound C or GSK3β inhibitor SB216763 blocked the cleavages of PARP and caspase 3 induced by ursolic acid in HepG2 cells. Furthermore, proteosomal inhibitor MG132 suppressed AMPK activation, GSK3β phosphorylation, cleaved PARP and deceased AEG‐1 induced by ursolic acid in HepG2 cells. Overall, our findings suggest that ursolic acid induced apoptosis in HepG2 cells via AMPK activation and GSK3β phosphorylation as a potent chemopreventive agent. Copyright © 2013 John Wiley & Sons, Ltd.     

Graveoline Isolated from Ethanolic Extract of Ruta graveolens Triggers Apoptosis and Autophagy in Skin Melanoma Cells: A Novel Apoptosis‐Independent Autophagic Signaling Pathway

Anti‐cancer drugs generally kill cancer cells by apoptosis but fail to do so when they become resistant and escape apoptosis signals. But these resistant cells can still be killed by autophagy. Therefore, drugs having both apoptotic and autophagic abilities are solicited in effective cancer management. In search of such a drug, we examined the efficacy of graveoline, a bioactive compound isolated from Ruta graveolens on skin melanoma A375 cells through the use of specific signaling cascades and their inhibitors. Cytotoxicity of graveoline was tested by conducting MTT assay. Induction of autophagy and apoptosis was checked. Expression of related proteins and their localization were studied by conducting immunoblot assay and through confocal microscopy, respectively. We found graveoline‐induced Beclin‐1 associated autophagy in A375 cells and 3‐methyladenine, an inhibitor of autophagy did not affect apoptosis. Conversely, caspase inhibitor that blocked apoptosis did not affect autophagic cell death, suggesting thereby that these two were independent events. Use of reactive oxygen species (ROS) scavengers inhibited cell death, but blocking autophagy did not affect graveoline‐induced ROS generation, suggesting that ROS generation ensued autophagy. Thus, graveoline‐induced both apoptotic and autophagic cell death in skin melanoma cells, a desirable quality in effective anti‐cancer drug design. Copyright © 2013 John Wiley & Sons, Ltd.     

养心康片通过Akt/AMPK-mTOR通路对心肌梗死后心力衰竭模型兔心肌细胞自噬的影响

目的观察养心康片通过Akt/AMPK-mTOR通路对心肌梗死后心力衰竭模型兔心肌细胞自噬的影响。方法对实验兔应用结扎冠脉的方法建立心肌梗死后心力衰竭兔模型,随机分为模型组、养心康组、AMPK抑制剂组、Akt抑制剂组和mTOR抑制剂组。并另取不造模的兔设立空白对照组。每组5只,共30只。造模后第3天开始分别给予相应的处理措施,共4周。观察养心康片对模型兔心肌beclin 1、LC3蛋白表达,心肌beclin 1和Atg5 mRNA的表达的影响,电镜检测各组心肌细胞超微结构。结果养心康组的beclin 1 mRNA的表达量、beclin 1蛋白表达量较模型组、mTOR抑制剂组降低(P<0.05或P<0.01),较空白对照组、AMPK抑制剂组升高(P<0.05或P<0.01);养心康组的LC3-Ⅱ/LC3-I比值较模型组、mTOR抑制剂组降低(P<0.05),较空白对照组、AMPK抑制剂组升高(P<0.05)。养心康组的Atg5 mRNA表达量较模型组降低(P<0.05),较空白对照组、AMPK抑制剂组升高(P<0.05或P<0.01)。电镜结果显示养心康组的自噬体、自噬体溶酶体数量较模型组、Akt抑制剂组和mTOR抑制剂组降低减少,较AMPK抑制剂组增多。结论养心康片可通过干预Akt/AMPK-mTOR通路调控心肌细胞自噬水平,改善心肌梗死后心衰模型的心肌细胞超微结构。     

补肾活血法调控PI3K/AKT/mTOR通路修复卵巢颗粒细胞自噬损伤机制研究

目的:观察补肾活血法调控磷脂酰肌醇3-激酶/蛋白激酶B/哺乳动物雷帕霉素靶蛋白(PI3K/AKT/mTOR)通路对体外培养大鼠卵巢颗粒细胞(OGCs)自噬损伤的影响。方法:将原代培养的大鼠卵巢颗粒细胞分为六组：空白对照组、模型组、中药低剂量组、中药中剂量组、中药高剂量组、果纳芬组。采用ELISA法检测各组中雌二醇(E₂)、孕酮(P)分泌量;Western blot法和免疫荧光法分别检测各组OGCs中PI3K、AKT、mTOR及自噬关键分子酵母Atg6同系物1(Beclin 1)、微管相关蛋1轻链3(LC3)、自噬受体蛋白p62的蛋白表达。结果:模型组E₂含量显著降低,中药各剂量组E₂含量均上升(均P<0.05),且中药高剂量组与果纳芬组E₂含量相当;各组对P的含量均没有影响(均P>0.05)。中药各剂量组及果纳芬组p-PI3K、p-AKT、p-mTOR水平和p62的表达上调,Beclin 1和LC3Ⅱ/LC3Ⅰ的表达下调,且中药高剂量组效果优于果纳芬组(均P<0.05)。结论:补肾...     

Paris saponin VII induces cell cycle arrest and apoptosis by regulating Akt/MAPK pathway and inhibition of P‐glycoprotein in K562/ADR cells

Paris saponinVII (PSVII) is a steroidal saponin isolated from the roots and rhizomes of Trillium tschonoskii Maxim. We found that PSVII could inhibit the growth of adriamycin‐resistant human leukemia cells (K562/ADR) in a dose‐dependent manner. Furthermore, the molecular mechanism underlying the cytotoxicity and downregulation of P‐glycoprotein (P‐gp) expression by PSVII was clarified. PSVII significantly suppressed cell proliferation by cell cycle arrest in the G0/G1 phase, which was associated with an obvious decrease in cyclin B1/D1 and CDK2/4/6 protein expression. Moreover, PSVII could attenuate mitochondrial membrane potential, increase the expression of apoptosis‐related proteins, such as Bax and cytochrome c, and decrease the protein expression levels of Bcl‐2, caspase‐9, caspase‐3, PARP‐1, and p‐Akt. We also found that JNK, ERK1/2, and p38 were regulated by PSVII in K562/ADR cells. And further studies indicated that the decrease in the reactive oxygen species level inhibited intrinsic P‐gp expression. Therefore, PSVII‐induced apoptosis in K562/ADR cells was associated with Akt/MAPK and the inhibition of P‐gp. In addition, PSVII induced a robust autophagy in K562/ADR cells as demonstrated by the degradation of LC3‐I. These results provide a biochemical basis for possible clinical applications of PSVII in the treatment of leukemia.     

当归多糖对糖尿病肾病KK-Ay小鼠肾脏AMPK信号通路及线粒体自噬的影响

目的 研究当归多糖对糖尿病肾病（diabetic nephropathy,DN）KK-Ay小鼠肾脏磷酸腺苷激活的蛋白激酶（AMPactivated protein kinase,AMPK）信号通路及线粒体自噬的影响。方法 SPF级雄性KK-Ay小鼠用高糖高脂饲料喂养,随机分为模型组、厄贝沙坦（25 mg/kg）组和当归多糖高、中、低剂量（400、200、100 mg/kg）组,每组10只;将10只雄性C57BL/6J小鼠作为对照组。给予药物干预4周,观察小鼠一般情况,每周称定体质量并检测血糖;末次给药后,心脏取血并处死小鼠,分离血清检测尿微量白蛋白（urine microalbuminuria,U-ALB）、肌酐（creatinine,SCr）、尿素氮（urea nitrogen,BUN）;采用苏木素-伊红（HE）染色观察肾组织病理变化;采用Western blotting检测肾组织线粒体自噬相关蛋白[微管相关蛋白1轻链3(microtubule-associated protein 1 light chain 3,LC3)、p62、Nix]和线粒体裂变蛋白[线粒体动力相关蛋白1(dy...