粉防己碱通过抑制PI3K/AKT/mTOR信号通路诱导卵巢癌细胞自噬

目的:研究粉防己碱(tetrandrine)对人卵巢浆液性囊腺癌SKOV3细胞活力及自噬的影响,并初步探讨其作用机制。方法:采用MTT法检测不同作用浓度的粉防己碱对SKOV3细胞活力的影响。采用吖啶橙染色法观察粉防己碱对SKOV3细胞中自噬溶酶体形成的影响。Western blot法检测粉防己碱处理前后SKOV3细胞自噬相关蛋白LC3的表达情况及相关信号通路的变化。最后,采用MTT法检测粉防己碱单用及联合自噬抑制剂3-甲基腺嘌呤(3-MA)对SKOV3细胞活力的影响。结果:粉防己碱可显著抑制SKOV3细胞的活力(P<0.01),作用24 h其半数抑制浓度为15.21μmol/L。吖啶橙染色结果显示,粉防己碱明显促进SKOV3细胞中自噬溶酶体的生成。Western blot实验结果显示,粉防己碱干预后,SKOV3细胞中LC3-Ⅱ和P62蛋白的表达水平明显上调;同时,粉防己碱能明显降低PI3K/AKT/mTOR信号通路中p-mTOR和p-AKT蛋白的水平(P<0.01)。自噬抑制剂3-MA增强了粉防己碱对SKOV3细胞活力的抑制作用。结论:粉防己碱可通过抑制PI3K/AKT/m...     

槲皮素通过PTEN/PI3K/JNK信号通路减轻小鼠RAW264.7巨噬细胞炎症

目的：探讨槲皮素（quercetin, Que）对细菌脂多糖（lipopolysaccharide, LPS）诱导的小鼠巨噬细胞炎症模型的抗炎效应及其与第10号染色体缺失的磷酸酶及张力蛋白同源蛋白（phosphatase and tensin homolog deleted on chromosome ten, PTEN）/磷脂酰肌醇3-激酶（phosphatidylinositol 3-kinase, PI3K）信号通路联合抗炎的效果和机制。方法：以小鼠巨噬细胞RAW264.7为研究对象。采用CCK-8实验确认0～100μmol/L Que的安全实验浓度。将细胞分为对照组、LPS炎症细胞模型组（LPS组）和不同浓度的Que处理LPS炎症细胞模型组（Que组）。Griess法检测各组细胞内一氧化氮（nitric oxide, NO）的分泌;ELISA法检测各组细胞上清液中白细胞介素1β(interleukin-1β,IL-1β)、IL-6和肿瘤坏死因子α(tumor necrosis factor-α, TNF-α)的表达;RT-qPCR、Western blot和免疫荧光法检测Que...     

lncRNA-CCAT1通过调控PI3K/Akt/mTOR信号通路对宫颈癌HeLa细胞自噬的影响

目的:探讨长链非编码RNA(lncRNA)结肠癌相关转录因子1(CCAT1)对宫颈癌HeLa细胞自噬的影响及其可能作用机制.方法:培养宫颈癌HeLa细胞,将CCAT1过表达质粒pcDNA3.1-CCAT1转染至HeLa细胞中,采用qRT-PCR检测转染后细胞中CCAT1的表达水平;CCK8法检测细胞增殖活性;单丹磺酰戊...     

双氢青蒿素通过调控PI3K/AKT通路增强肝癌H22细胞荷瘤小鼠放疗效果

目的:探讨双氢青蒿素(DHA)调控磷脂酰肌醇3-激酶(PI3K)/蛋白激酶B(AKT)通路对肝细胞癌H22细胞荷瘤小鼠放疗增效的影响。方法:构建肝癌H22细胞荷瘤小鼠模型,实验分为模型组、单放疗组、5-氟尿嘧啶(5-FU)组和低、中、高剂量DHA组,每组8只,按照分组进行给药和放疗治疗。隔天测量各组荷瘤小鼠体重和瘤体积,给药结束后鼠尾取血后立刻脱颈处死小鼠。观察DHA对放疗的增效作用和对肿瘤生长的抑制作用,测定淋巴细胞转化程度和自然杀伤(NK)细胞活性,ELISA法检测小鼠血清白细胞介素2(IL-2)和IL-4水平,Western blot法测定小鼠肿瘤组织中PI3K、AKT和p-AKT蛋白水平。结果:成功构建肝癌H22细胞荷瘤小鼠模型。与模型组相比,单放疗组肿瘤3倍倍增时间(TGT3)显著升高(P<0.05),瘤重、淋巴细胞转化程度、NK细胞活性、IL-2和IL-4水平、PI3K表达水平和AKT磷酸化水平均显著降低(P<0.05);与单放疗组相比,随着DHA剂量升高,TGT3、增敏系数、抑瘤率、淋巴细胞转化程度、NK细胞活性及IL-2和IL-4水平随之升高(P<0....     

PI3K/AKT通路介导H_2O_2预处理减轻PC12细胞氧化损伤

目的探讨PI3K/AKT信号通路是否参与H2O2预处理诱导的适应性细胞保护作用。方法体外培养PC12细胞,建立H2O2预处理对抗高浓度H2O2诱导细胞损伤的实验模型。应用甲氮甲唑蓝(MTT)法测定细胞的存活率,比色法测定乳酸脱氢酶(LDH)的活性,碘化丙啶(PI)染色流式细胞术检测细胞凋亡率,免疫印迹法(Westernblot)测定AKT的表达。结果 100μmol H2O2预处理PC12细胞90 min可显著地抑制300μmol H2O2引起的损伤,使细胞存活率从50.2%±4.6%升高至83.8%±3.5%,LDH活性由103%±10.2%下降至68.5%±5.3%,细胞凋亡率由65.5%±4.1%下降至37.1%±2.3%(P<0.01)。100μmol H2O2预处理诱导p-AKT的表达,PI3K抑制剂ly294002阻断了H2O2预处理引起的p-AKT表达。同时ly294002拮抗了H2O2预处理诱导的抗细胞损伤和凋亡作用。结论 H2O2预处理通过PI3K途径引起AKT的活化,PI3K/AKT通路的活化介导了H2O2预处理诱导的适应性细胞保护作用。     

胃癌中LINC00659的表达及其通过调控PI3K/AKT信号通路影响胃癌细胞增殖

目的 探讨LINC00659在胃癌组织及胃癌细胞中的表达,并探讨其通过调控PI3K/AKT信号通路影响胃癌细胞增殖的分子机制。方法 采用qRT-PCR法检测LINC00659在胃癌组织及人胃癌细胞株中的表达情况;构建慢病毒介导LINC00659敲减或过表达胃癌细胞株模型,qRT-PCR法检测转染效率;CCK-8法检测LINC00659对胃癌细胞增殖能力的影响;克隆形成实验检测细胞集落形成能力;Western blot法检测敲减或过表达LINC00659后胃癌细胞中Ki-67、PCNA、PI3K和p-AKT蛋白表达水平。结果 LINC00659在胃癌组织和人胃癌细胞株中高表达(P<0.01);qRT-PCR结果显示,慢病毒感染胃癌细胞后,成功敲减或过表达LINC00659(P<0.01);CCK-8法结果显示：敲减LINC00659显著抑制胃癌AGS细胞的增殖活力,过表达LINC00659促进HGC-27细胞增殖活力(P<0.05);克隆形成实验结果显示,敲减LINC00659抑制AGS细胞的集落形成能力,过表达LINC00659促进胃癌HGC-27细胞集落形成能力(P...     

PI3K/Akt信号通路在脓毒症肾脏损伤诱导的自噬中的调节作用*

 目的：研究脓毒症造成肾脏损伤时的自噬情况以及磷脂酰肌醇3-激酶（PI3K）/蛋白激酶B(Akt)信号通路的调节作用。方法：对大鼠盲肠进行结扎与穿刺（CLP）,对肾脏组织切片进行HE染色,并测定血清尿素氮和肌酐。通过Western blotting定量分析CLP大鼠肾脏损伤发生后不同时点自噬相关分子微管相关蛋白轻链3（LC3）Ⅰ/Ⅱ、beclin-1和Akt蛋白磷酸化的表达情况;体外用LPS诱导人近端肾小管上皮细胞株HK-2发生自噬,检测不同浓度LPS和不同刺激时间自噬相关分子LC3Ⅰ/Ⅱ和Akt蛋白磷酸化的表达情况;进一步使用PI3K抑制剂、Akt抑制剂和LPS刺激HK-2细胞观察自噬相关蛋白的表达情况及细胞的凋亡水平。结果：同对照组相比,CLP大鼠显微镜下可见肾损伤的典型病理改变,血清尿素氮和肌酐均有上升。CLP肾脏损伤发生后,自噬相关蛋白LC3Ⅰ/Ⅱ、beclin-1含量及Akt磷酸化水平均有上升。LPS刺激HK-2细胞后,随着刺激浓度的增加,p-Akt(308)表达量逐渐提高,而LC3Ⅰ/Ⅱ及p-Akt(472)的表达量在10 mg/L LPS刺激组最高。随着刺激时间的延长,p-Akt(308)表达量逐渐提高;LC3Ⅰ/Ⅱ表达量同p-Akt(472)在刺激8 h时最高;使用PI3K抑制剂及Akt抑制剂后,LPS诱导的LC3表达显著下调,HK-2细胞凋亡明显增加。结论：CLP肾脏损伤发生时可以诱导自噬发生, PI3K／Akt信号通路在其中发挥重要调节作用。     

PI3K/AKT信号通路在全肝缺血再灌注大鼠肺损伤中的作用

目的 探讨磷脂酰肌醇-3激酶（PI3K）/AKT通路在大鼠全肝缺血再灌注肺损伤中作用。方法 本实验分两部分。(1)36只大鼠分别于肝缺血前与再灌注后不同时点处死取肺。（2）12只大鼠分成Wortmannin组与模型对照组。分别应用Western blot、原位末端转移酶(TUNEL)法与免疫组化法检测肺AKT、磷酸化AKT（p-AKT）表达、细胞凋亡与增殖细胞核抗原（PCNA）表达。结果（1）与缺血前相比,缺血再灌注后肺细胞凋亡指数显著增高; p-AKT/AKT与PCNA阳性指数呈双相变化;肺病理改变严重。（2）p-AKT/AKT与PCNA阳性指数成正相关;与凋亡指数呈负相关。（3)与模型对照组相比,Wortmannin组p-AKT/AKT与PCNA阳性指数显著降低,细胞凋亡指数显著增高,病理改变加重。结论 PI3K/AKT通路可能通过抑制凋亡、促进增殖对全肝缺血再灌注肺损伤发挥保护作用。     

PI3K/Akt/mTOR信号通路在巨噬细胞自噬及动脉粥样硬化斑块不稳定中的作用

 目的：探讨磷脂酰肌醇3-激酶（PI3K）/蛋白激酶B(Akt)/哺乳动物雷帕霉素靶蛋白(mTOR)信号通路在巨噬细胞自体吞噬以及动脉粥样硬化斑块不稳定中的作用。方法：利用Akt抑制剂康士得（20 μmol/L）、mTOR抑制剂雷帕霉素（10 nmol/L）及mTOR-siRNA（30 nmol/L）体外处理小鼠RAW 264.7 巨噬细胞株 48 h后,透射电镜观察巨噬细胞自噬体的变化,细胞免疫荧光法及Western blotting法检测微管相关蛋白LC3-II表达,实时荧光定量qRT-PCR和Western blotting法检测Akt、mTOR及自噬相关蛋白Beclin 1的表达,ELISA检测巨噬细胞分泌炎症因子水平。体内实验中, 24只雄性新西兰兔给予球囊损伤+ 1%胆固醇喂养8周,然后随机分为对照组、康士得（1.0 mg·kg-1·d-1）组和雷帕霉素（0.5 mg·kg-1·d-1）组,每组8只,干预4周。血管内超声（IVUS）检测斑块的影像学特征,透射电镜观察斑块中巨噬细胞超微结构的改变,免疫荧光法检测微管相关蛋白LC3-II表达,免疫组织化学法检测巨噬细胞Akt和mTOR的蛋白表达。 结果：与对照组比较,康士得、雷帕霉素及mTOR-siRNA干预巨噬细胞后,透射电镜下观察到自噬体明显增多,微管相关蛋白LC3-II和自噬相关蛋白Beclin 1的表达水平明显上调,而Akt及mTOR 的mRNA及蛋白表达水平明显减少,巨噬细胞分泌的IL-10明显降低,而IFN-γ的分泌显著增加。体内实验： IVUS显示,与对照组比较,康士得组及雷帕霉素组的外弹性膜面积（EEMA）、斑块面积（PA）及斑块负荷（PB）明显减少,透射电镜下观察到巨噬细胞中自噬体增加,组织免疫荧光法示LC3-II明显增加,HE染色显示斑块纤维帽的厚度明显增加,内、中膜厚度显著减低,组织免疫组化染色显示巨噬细胞RAM-11及p-mTOR染色显著减少。结论：选择性抑制PI3K/Akt/mTOR信号通路能诱导巨噬细胞自噬,减少斑块巨噬细胞的浸润, 抑制炎症反应进而稳定动脉粥样硬化易损斑块。     

乌骨藤提取物通过调控PI3K/AKT/mTOR信号通路抑制黑色素瘤细胞的活力并诱导细胞凋亡

目的:探究乌骨藤提取物(Marsdenia tenacissima extract,MTE)对黑色素瘤细胞活力及凋亡的作用及机制。方法:用不同浓度(0、50、100和200 mg/L) MTE处理小鼠皮肤黑色素瘤B16-F10细胞24 h或不同浓度MTE处理不同时间(0、24、48、72和96 h),MTT法检测细胞活力。流式细胞术检测细胞凋亡情况,Western blot法检测细胞增殖、凋亡和PI3K/AKT/mTOR通路相关蛋白的表达,同时检测通路激动剂胰岛素样生长因子1(IGF-1)处理细胞后p-PI3K及细胞增殖和凋亡相关蛋白的表达。结果:根据预实验结果,选择MTE作用时间为72 h。MTE浓度为100 mg/L和200 mg/L时能明显抑制B16-F10细胞活力及增殖相关蛋白Ki67和PCNA的表达,并且还可诱导B16-F10细胞凋亡,提高凋亡相关蛋白cleaved caspase-3和cleaved caspase-9的蛋白水平;同时,MTE还可显著降低p-PI3K、p-AKT和mTOR的蛋白水平;此外,激动剂IGF-1可明显减弱MTE抑制细胞活力及诱导细胞凋亡的作用。结论:MTE可通过下调PI3K/AKT/mTOR通路活性抑制黑色素瘤细胞活力,诱导细胞凋亡。     

槲皮苷通过抑制PI3K/AKT信号通路诱导胃癌SGC7901细胞凋亡

目的:探讨槲皮苷是否通过抑制PI3K/AKT信号通路诱导人胃癌SGC7901细胞凋亡。方法:选取SGC7901细胞作为研究对象,采用MTT法检测槲皮苷对SGC7901细胞的毒性作用并测定IC50值。实验分为对照组(不加药处理)、槲皮苷组(采用200μmol/L槲皮苷处理)、PI3K/AKT通路激动剂胰岛素样生长因子1(IGF-1)组(采用100μg/L IGF-1处理)和槲皮苷+IGF-1组(采用200μmol/L槲皮苷+100μg/L IGF-1共处理)。处理48 h后,采用流式细胞术检测细胞凋亡,Western blot法检测cleaved caspase-3、p-AKT(Ser473)、AKT、p-PI3K(Tyr508)和PI3K的蛋白水平。结果:从100μmol/L开始,随着槲皮苷处理浓度的逐渐升高,SGC7901细胞活力显著降低(P 0. 05),槲皮苷作用48 h的IC50值为275. 40μmol/L。200μmol/L槲皮苷作用SGC7901细胞48 h后,与对照组比较,细胞凋亡率和cleaved caspase-3蛋白水平显著上升(P 0. 05),p-AKT和p-PI3K蛋白水平显著降低(P 0. 05),然而IGF-1与槲皮苷共同作用时,IGF-1可逆转槲皮苷对SGC7901细胞的作用效果。结论:槲皮苷能够诱导胃癌SGC7901细胞凋亡,其作用机制可能与抑制PI3K/AKT信号通路的激活有关。     

M3R激动剂通过激活PI3K/AKT信号途径促进肺癌细胞A549的上皮间质转化

目的:探讨毒蕈碱胆碱受体3(muscarinic receptor 3,M3R)激动剂卡巴胆碱促进人肺癌A549细胞上皮间质转化的可能信号通路。方法:用400μmol/L卡巴胆碱刺激人肺癌A549细胞,在倒置相差显微镜下观察细胞形态的变化,应用划痕愈合实验和Transwell实验观察细胞迁移和侵袭能力;应用q PCR技术检测上皮间质转化相关蛋白波形蛋白(vimentin)和E钙黏蛋白(E-cadherin)m RNA水平的变化;应用Western blot技术检测p-AKT、vimentin和E-cadherin蛋白水平的变化。结果:卡巴胆碱刺激人肺癌A549细胞后,细胞形态发生明显改变,由不规则多边形逐渐向梭形转化、细胞间紧密结合逐渐变得松散,细胞迁移和侵袭能力增强;vimentin的m RNA和蛋白表达量明显增加,E-cadherin的m RNA和蛋白水平降低,磷酸化的AKT蛋白水平增加,且这些变化均可被M3R特异性抑制剂4-DAMP所抑制(P0.05)。结论:卡巴胆碱可通过激活PI3K/AKT信号途径促进人肺癌A549细胞发生上皮间质转化。     

PI3K/AKT信号通路在SjCystatin诱导M2巨噬细胞分化过程中的影响

目的:进一步确定日本血吸虫半胱氨酸蛋白酶抑制剂(Sj Cystatin)诱导M2巨噬细胞分化的亚型及相关机制。方法:用ELISA、RT-q PCR或Western blot法测定IL-10、IL-12、巨噬细胞亚型表面标志物LIGHT(M2b)及Arg-1(M2a+M2c)的表达;用Western blot法测定AKT的磷酸化水平。结果:Sj Cystatin处理组在6 h、12 h和24h时IL-10表达量持续增加;处理12 h,LIGHT的mRNA和蛋白表达量增加但Arg-1的mRNA和蛋白表达量降低;AKT磷酸化水平增加。PI3K/AKT抑制剂处理组IL-10的释放量在12 h和24 h持续降低;24 h,LIGHT的mRNA和蛋白表达量降低但Arg-1的mRNA和蛋白表达量增加;AKT的磷酸化水平减少。结论:Sj Cystatin促进了活化的M2巨噬细胞分化为M2b亚型巨噬细胞,并且PI3K/AKT信号通路参与了这一过程。     

Administration of dexamethasone protects mice against ischemia/reperfusion induced renal injury by suppressing PI3K/AKT signaling

Dexamethasone (DEX), a ligand for glucocorticoid receptor (GR), has long been used in the clinical practice due to its anti-inflammatory and immunosuppressive properties. Given that ischemia/reperfusion (IR)-induced renal injury is featured by the excessive immune response; the current study is therefore designed to address the impact of dexamethasone on IR-induced renal injury, a common disorder in the clinical settings. Precondition of mice with 4 mg/kg of dexamethasone significantly attenuated IR-induced injury as manifested by the improved renal function along with ameliorated pathological changes and suppressed inflammatory infiltration. Mechanistic studies revealed that dexamethasone promotes GR activation, and by which it attenuates the signals for PI3K/AKT activation. Attenuated PI3K/AKT signaling thus suppresses inflammatory response which then protects kidneys from IR-induced injury. All together, our data support that dexamethasone could be a good alternative therapy for prevention and treatment of IR-induced renal injury in the clinical practice.     

Lycopene alleviates food allergy by modulating the PI3K/AKT pathway in peanut-sensitized BALB/c mice

Food allergies, which lead to life-threatening acute symptoms, are considered an important public health problem. Therefore, it is essential to develop efficient preventive and treatment measures. We developed a crude peanut protein extract (PPE)–induced allergy mouse model to investigate the effects of lycopene on peanut allergy. Mice were divided into four groups: 5 mg/kg lycopene, 20 mg/kg lycopene, no treatment, and control groups. Serum inflammatory factors were detected using enzyme-linked immunosorbent assay. In addition, pathology and immunohistochemistry analyses were used to examine the small intestine of mice. We found that lycopene decreased PPE-specific immunoglobulin E (IgE) and IL-13 levels in the serum, relieved small intestine inflammation, attenuated the production of histamine and mouse mast cell protease-1, and downregulated PI3K and AKT1 expression in the small intestine tissues of mice allergic to peanuts. Our results suggest that lycopene can ameliorate allergy by attenuating the PI3K/AKT pathway and the anaphylactic reactions mediated by PPE-specific IgE.     

LINC00323 mediates the role of M1 macrophage polarization in diabetic nephropathy through PI3K/AKT signaling pathway

ObjectiveTo explore the effect of LINC00323 on the polarization of M1 macrophages in diabetic nephropathy. To study the effect and biological mechanism of LINC00323 on the occurrence and development of diabetic nephropathy.MethodsWe used clinical samples to analyze the correlation between macrophage polarization and the occurrence and development of diabetic nephropathy. In addition, we used bioinformatics to analyze the key molecules of macrophage polarization. We then verified the key pathways that promote the M1 polarization of macrophages at the level of cell biology. And we verify the effectiveness of treatment against this target in animal experiments.ResultsWe analyzed in clinical samples that the expression of inflammatory factors (TNF-α and IL-6) increased in patients with diabetic nephropathy. In addition, we found that the expression of M1 marker protein CD86 increased through PCR and western blot analysis. We found a key target (LINC00323) through bioinformatics. The expression of LINC00323 in patients' blood samples is also at a high level. We further explored the mechanism of LINC00323 involved in the polarization of M1 macrophages at the level of cellular molecular biology, and found that it is closely related to the PI3K/AKT signaling pathway. In animal models, we found that inhibiting the expression of LINC00323 can reduce the damage of diabetic nephropathy.ConclusionWe found that LINC00323 mediates the polarization of M1 macrophages through the PI3K/AKT signaling pathway. LINC00323 plays an important role in the occurrence and development of diabetic nephropathy.     

PI3K/AKT signaling pathway plays a role in enhancement of eNOS activity by recombinant human angiotensin converting enzyme 2 in human umbilical vein endothelial cells

The aim of this study was to investigate the effect of PI3K/AKT signaling pathway in the activity of recombinant human angiotensin converting enzyme 2 (rhACE2) promoted the activity of endothelial nitric oxide synthase (eNOS). The human umbilical vein endothelial cells (HUVEC) were cultured in vitro. Then treated with Ang II (1×10^-6 mol/L) for 24 h. The rhACE2 (100 μmol/L) was added and incubated for 5, 10, 15, 30, 60 min respectively which was based on Ang II intervention. The effect of rhACE2 on phosphorylation eNOS level was also observed in the presence of {"type":"entrez-nucleotide","attrs":{"text":"LY294002","term_id":"1257998346","term_text":"LY294002"}}LY294002 (10 μmol/L) (PI3K/AKT inhibitors). Griess reagent method was applied to measure NO contents in cell culture supernatant, RT-PCR to detect the expression of eNOSmRNA in HUVEC, and Western blot to detect the expression of eNOS and phosphorylated eNOS. In Ang II intervention group, NO contents were significantly lower than control group (P < 0.05). Through rhACE2 treatment, the NO contents in cell culture medium and the expression level of phosphorylated eNOS were significantly higher than in Ang II intervention group (P < 0.05), but eNOSmRNA and non-phosphorylated eNOS protein expression level showed no significant difference (P > 0.05). After HUVEC was intervened by PI3K/AKT pathway inhibitor {"type":"entrez-nucleotide","attrs":{"text":"LY294002","term_id":"1257998346","term_text":"LY294002"}}LY294002, the expression level of phosphorylated eNOS was significantly lower than that in the rhACE2 30 min treatment group (P < 0.05). rhACE2 may reduce the activity of Ang II inhibited endothelial cell eNOS, which can be blocked by PI3K/AKT pathway inhibitor {"type":"entrez-nucleotide","attrs":{"text":"LY294002","term_id":"1257998346","term_text":"LY294002"}}LY294002, suggesting PI3K/AKT signaling pathway plays an important role in rhACE2’s promotion of the activity of endothelial cell eNOS.