A polysaccharide from Strongylocentrotus nudus eggs protects against myelosuppression and immunosuppression in cyclophosphamide-treated mice

To assess the chemoprotective properties of a polysaccharide from Strongylocentrotus nudus eggs (SEP), myelosuppressed and immunosuppressed mouse models were generated by administration of cyclophosphamide (Cy) and then treated with SEP. SEP (16 mg/kg/d) remarkably increased spleen and thymus indices, activated the proliferation of leukocytes and erythrocytes and platelets from peripheral blood, and exhibited co-mitogenic activity on ConA- or LPS-stimulated splenocytes in a dose-dependent manner. An increased percentage of CD34⁺ cells in bone marrow of Cy-treated mice was also observed. Furthermore, SEP elevated CD4⁺ T lymphocyte counts as well as the CD4/CD8 ratio dose-dependently, and it increased interleukin-2 (IL-2), IgA, IgM, and IgG levels in the sera of Cy-treated mice. Pre-incubation with TLR2 and TLR4 blocking antibodies inhibited splenocyte proliferation and its IL-2 secretion. Finally, SEP significantly induced Akt phosphorylation in splenocytes from Cy-treated mice, suggesting that chemoprotection by SEP was mediated through the PI3K/Akt signaling pathway. These findings indicate that SEP plays an important role in the protection against myelosuppression and immunosuppression in Cy-treated mice and could be a potential immunomodulatory agent.     

PI3K/Akt/mTOR信号通路与肿瘤

在近年来的肿瘤治疗中,靶向生物治疗逐渐成为研究的热点。该文就磷脂酰肌醇3-激酶/蛋白激酶B/哺乳动物雷帕霉素靶蛋白[phosphatidylinositol-3-kinase(PI3K)/protein kinase B(Akt)/the mammalian target of Rapamycin(mTOR),PI3K/Akt/mTOR]信号通路予以综述,重点包括PI3K/Akt/mTOR信号转导在肿瘤机制中作用以及肿瘤治疗过程中耐药性方面的关系等。     

Effects of ginsenoside compound K combined with cisplatin on the proliferation,apoptosis and epithelial mesenchymal transition in MCF-7 cells of human breast cancer

Context: Breast cancer seriously harms the health of women and there are currently few therapeutic options for patients with breast cancer.

Objective: Effects of ginsenoside compound K (CK) in combination with cisplatin (DDP) on the proliferation, apoptosis, and epithelial mesenchymal transition (EMT) of MCF-7 cells were studied.

Materials and methods: MCF-7 cells were divided into CK (50?μmol/L) group, DDP (10?mg/L) group, CK (50?μmol/L)?+DDP (10?mg/L) group, and control (CON) group. The cells in the CON group were not treated with any drugs. Proliferation, apoptosis, expression of E-cadherin, N-cadherin, vimentin, protein kinase B (Akt), phosphorylated Akt (p-Akt), and level of fibronectin (FN) in MCF-7 cells were detected by methyl thiazolyl tetrazolium (MTT), flow cytometry, western blotting, and enzyme-linked immuno sorbent assay (ELISA), respectively.

Results: The proliferation inhibition rates in CK, DDP, and CK?+?DDP groups at 48?h were 19.18?±?2.25, 21.34?±?2.84, and 43.37?±?5.62, respectively. The apoptosis rates were 2.85?±?0.56, 13.37?±?2.28, 20.04?±?2.92, and 30.78?±?4.64 at 24?h and 3.14?±?0.72, 20.36?±?3.28, 27.58?±?4.09, and 41.62?±?5.83 at 48?h in CON, CK, DDP, and CK?+?DDP groups, respectively. CK or DDP alone and their combination all could reduce the levels of N-cadherin, vimentin, p-Akt/Akt, and FN and elevate level of E-cadherin.

Discussion and conclusion: Both CK and DDP can inhibit the proliferation, EMT, and induce the apoptosis in MCF-7 cells, which may be related to the PI3K/Akt pathway. In addition, the combination of CK with DDP can produce a better effect.     

五味子乙素联合泼尼松调节PI3K/Akt信号通路改善大鼠膜性肾病研究

目的 研究五味子乙素联合泼尼松对膜性肾病大鼠的作用及对其对PI3K/Akt信号通路的影响。方法 取15只SD大鼠作为对照组,60只大鼠采用阳离子化牛血清白蛋白（C-BSA）建立膜性肾病模型,造模完成后的大鼠随机分为模型组、泼尼松（2 mg/kg）组、五味子乙素（30 mg/kg）组、五味子乙素（30 mg/kg） ＋泼尼松（2 mg/kg）组。连续给药28 d后,分别测定各组大鼠24 h尿蛋白量、血清总胆固醇（TC）、三酰甘油（TG）、丙二醛（MDA）、超氧化物歧化酶（SOD）、尿素氮（BUN）及肌酐（Scr）水平,苏木精-伊红染色法进行组织病理学检查,Western blotting法检测大鼠肾脏p-Akt、Akt、PI3K-P85、PI3K-P110蛋白表达水平。结果 与模型组比较,泼尼松组、五味子乙素组、五味子乙素＋泼尼松组大鼠24 h尿蛋白量和血清TC、TG、MDA、BUN及Scr水平均显著降低（P<0.05）,SOD水平显著升高（P<0.05）,组织病理学明显改善,肾脏p-Akt、Akt、PI3K-P85、PI3K-P110蛋白表达水平均显著降低（P<0.05）,且五味子乙素＋泼尼松组各项指标均优于单给药组。结论 五味子乙素联合泼尼松对大鼠膜性肾病发挥显著改善作用,作用优于单给药,其机制可能与调节PI3K/Akt信号通路有关。     

脂肪酸酰胺水解酶抑制剂URB597对人肝癌细胞MHCC97H生长和侵袭的抑制作用及机制研究

目的：观察脂肪酸酰胺水解酶抑制剂URB597对人肝癌高转移细胞MHCC97H细胞生长和侵袭性的抑制作用。方法：不同浓度URB597（1、5、10μmol/L）作用于MHCC97H细胞后不同时间,应用MTT法及流式细胞仪检测该种细胞生长活力及凋亡细胞数目的改变;应用Transwell实验检测该种细胞的运动能力及侵袭能力;应用蛋白质印迹法检测该种细胞内磷酸化Akt（p-Akt）和Akt表达量的变化。结果：上述3种浓度的URB597作用于该种细胞3-7d后,细胞活力明显降低,呈时间及剂量依赖性;10μmol/L URB597作用3-7d可显著增加凋亡细胞数目。URB597作用于细胞48h后,与对照组比较,5、10μmol/L URB597可显著抑制MHCC97H细胞侵袭能力（P〈0.01,P〈0.001）。3种浓度URB597作用于细胞24h后,5、10μmol/L URB597可显著下调细胞内p-Akt水平（P〈0.05,P〈0.01）。结论：URB597对体外生长的人肝癌细胞MHCC97H的生长和侵袭有明显抑制作用,该作用可能与其抑制磷酯酰肌醇-3激酶（PI3K）/Akt信号通路有关。     

补骨脂素对绝经后大鼠骨质疏松及PI3K/Akt/mTOR信号通路的影响

目的:研究补骨脂素对绝经后大鼠骨质疏松及磷脂酰肌醇3激酶(PI3K)/蛋白激酶B(Akt)/哺乳动物雷帕霉素靶蛋白(mTOR)信号通路的影响。方法:将60只健康雌性SD大鼠随机分为正常组、模型组、阳性对照组(0.09 mg/kg雌二醇)和补骨脂素低、中、高剂量组(22、44、88 mg/kg),每组10只。除正常组外,其余各组大鼠均采用卵巢摘除去势法建立绝经后骨质疏松模型。术后正常饲养2个月,正常组和模型组大鼠灌胃等体积生理盐水,各药物组大鼠灌胃相应药液;灌胃体积均为0.005 mL/g,每天1次,连续98天。末次给药24 h后,测定大鼠右侧下肢股骨和椎骨的骨密度,血清中钙离子、骨钙素、Ⅰ型前胶原N端前肽(P1NP)含量和骨形态发生蛋白2(BMP2)、血管内皮生长因子(VEGF)水平,以及股骨组织中PI3K、Akt、mTOR mRNA及蛋白的表达水平。结果:与正常组比较,模型组大鼠股骨和椎骨的骨密度以及血清中钙离子、骨钙素、P1NP含量和BMP2、VEGF水平均显著降低,PI3K、Akt、mTOR mRNA及蛋白的表达水平均显著升高(P<0.05或P<0.01)。与模型组比较,补骨脂素中、高剂量组和阳性对照组大鼠股骨和椎骨的骨密度以及血清中钙离子、骨钙素、P1NP含量和BMP2(补骨脂素中剂量组除外)、VEGF(补骨脂素中剂量组除外)水平均显著升高,各药物组PI3K、Akt、m TOR mRNA(补骨脂素低剂量组除外)及蛋白表达水平均显著降低(P<0.05或P<0.01),且高剂量组股骨骨密度和钙离子、BMP2水平以及PI3K蛋白表达水平均显著高于阳性对照组(P<0.05),mTOR mRNA表达水平显著低于阳性对照组(P<0.05)。结论:补骨脂素可改善绝经后大鼠的骨质疏松,其机制可能与抑制PI3K/Akt/mTOR信号通路有关。     

柚皮苷调控 PI3K/Akt/eNOS通路控制 2型糖尿病大鼠脑血管内皮氧化损伤的作用探讨

目的 探讨柚皮苷对2型糖尿病大鼠脑血管内皮氧化损伤的治疗效果,以及柚皮苷对3-磷酸肌醇激酶(PI3K)/蛋白激酶B(AKT)/内皮型一氧化氮(eNOS)信号通路的调控作用.方法 2019年3月15日至2020年5月20日,将SD大鼠(南京医科大学实验动物中心)按随机字母表法分为4组,对照组大鼠给予标准饲料,其他组给予高...     

PF-04691502 triggers cell cycle arrest,apoptosis and inhibits the angiogenesis in hepatocellular carcinoma cells

Hepatocellular carcinoma (HCC) is a major cause of morbidity and mortality in the world. The aim of the present study is to determine the antitumor effect of PF-04691502, a potent inhibitor of PI3K and mTOR kinases, on the apoptosis and angiogenesis of the hepatoma cancer cells. Our results indicate that treatment of cancer cells with PF-04691502 reduces cell viability and inhibits cell growth in a dose-dependent manner. PF-04691502 triggers apoptosis via a mitochondrial pathway, accompanied by activation of caspase-3, caspase-9, and poly(ADP-ribose) polymerase (PARP). Pre-treatment of hepatoma cells with the caspase-3 inhibitor (z-DEVD-fmk) blocks the PF-04691502-induced death of these cells. In addition, growth factors-induced tube formation and the migration of HUVECs are markedly inhibited by PF-04691502 treatment. The mechanisms of anti-angiogenesis of PF-04691502 are associated with inhibiting the expression of VEGF and HIF-1α. Based on the overall results, we suggest that PF-04691502 reduces hepatocellular carcinoma cell viability, induces cell apoptosis, and inhibits cell growth and tumor angiogenesis, implicating its potential therapeutic value in the treatment of HCC.     

Naphtho[1,2-b]furan-4,5-dione disrupts Janus kinase-2 and induces apoptosis in breast cancer MDA-MB-231 cells

Naphtho[1,2-b]furan-4,5-dione (NFD), prepared from 2-hydroxy-1,4-naphthoquinone and chloroacetaldehyde in an efficient one-pot reaction, exhibits an anti-carcinogenic effect. NFD-induced apoptosis in MDA-MB-231 cells, as indicated by the accumulation of sub-G1 population, externalization of phosphatidylserine, loss of mitochondrial membrane potential (ΔΨm) with subsequent release of cytochrome c, and activation of both capase-9 and caspase-3. This correlated with up-regulation in Bax and Bad, and down-regulation of various anti-apoptotic proteins, including Bcl-2, Bcl-X_L, Mcl-1, and survivin in NFD-treated cells. In the analysis of signal transduction pathway, NFD suppressed the phosphorylation of JAK2 in MDA-MB-231 cells without altering the expression of JAK2 protein. Activation of STAT3, Src, and PI3K/Akt were also inhibited by NFD. Moreover, the JAK2 inhibitor AG490 blocked JAK2, STAT3, Src, PI3K, and Akt activation, whereas both Src inhibitor PP2 and PI3K inhibitor wortmannin did not affect JAK2 activation. This suggests that STAT3, Src, and PI3K/Akt are downstream molecules of the JAK2 signaling pathway. AG490 treatment also mimics the cytotoxic effects of NFD. Taken together, these results indicate that NFD disrupts JAK2 pathway and induces apoptosis in MDA-MB-231 cells.     

Targeting the PI3K/AKT/mTOR signaling network in acute myelogenous leukemia

Background: The PI3K/Akt/mammalian target of rapamycin (mTOR) signaling pathway plays a central role in cell growth, proliferation and survival not only under physiological conditions but also in a variety of tumor cells. Therefore, the PI3K/Akt/mTOR axis may be a critical target for cancer therapy. Objective: This review discusses how PI3K/Akt/mTOR signaling network is constitutively active in acute myelogenous leukemia (AML), where it strongly influences proliferation, survival and drug-resistance of leukemic cells, and how effective targeting of this pathway with pharmacological inhibitors, used alone or in combination with existing drugs, may result in suppression of leukemic cell growth, including leukemic stem cells. Methods: We searched the literature for articles dealing with activation of this pathway in AML and highlighting the efficacy of small molecules directed against the PI3K/Akt/mTOR signaling cascade. Conclusions: The limit of acceptable toxicity for standard chemotherapy has been reached in AML. Therefore, new therapeutic strategies are needed. Targeting the PI3K/Akt/mTOR signaling network with small molecule inhibitors, alone or in combinations with other drugs, may result in less toxic and more efficacious treatment of AML patients. Efforts to exploit selective inhibitors of the PI3K/Akt/mTOR pathway that show effectiveness and safety in the clinical setting are currently underway.     

Erythropoietin protects the human myocardium against hypoxia/reoxygenation injury via phosphatidylinositol-3 kinase and ERK1/2 activation

BACKGROUND AND PURPOSES: Erythropoietin (EPO) has been shown to protect against myocardial infarction in animal studies by activating phosphatidylinositol-3 kinase (PI3K)/Akt and ERK1/2. However these pro-survival pathways are impaired in the diabetic heart. We investigated the ability of EPO to protect human atrial trabeculae from non-diabetic and diabetic patients undergoing coronary artery bypass surgery, against hypoxia-reoxygenation injury. EXPERIMENTAL APPROACH: Human atrial trabeculae were exposed to 90min hypoxia and 120min reoxygenation. EPO was administered throughout reoxygenation. The developed force of contraction, calculated as a percentage of baseline force of contraction, was continuously monitored. The involvement of PI3K and ERK1/2 and the levels of activated caspase 3(AC3) were assessed. KEY RESULTS: EPO improved the force of contraction in tissue from non-diabetic patients (46.7+/-1.7% vs. 30.2+/-2.2% in control, p<0.001). These beneficial effects were prevented by the PI3K inhibitor, LY294002 and the ERK1/2 inhibitor, U0126. EPO also significantly improved the force of contraction in the diabetic tissue, although to a lesser degree. The levels of activated caspase 3 were significantly reduced in EPO treated trabeculae from both non-diabetic and diabetic patients, relative to their respective untreated controls. CONCLUSIONS AND IMPLICATIONS: EPO administered at reoxygenation protected human myocardial muscle by activating PI3K and ERK1/2 and reducing the level of activated caspase 3. This cardioprotection was also observed in the diabetic group. This data supports the potential of EPO being used as a novel cardioprotective strategy either alone or as an adjunct in the clinical setting alongside existing reperfusion therapies.     

PI3K/Akt信号通路在硫化氢保护PC12细胞对抗化学性缺氧损伤的作用

目的探讨硫化氢(H2S)对PC12细胞PI3K/Akt信号通路的影响及该通路在H2S神经保护中的作用。方法Western blot法检测H2S供体硫氢化钠(NaHS)处理PC12细胞诱导Akt磷酸化的水平;CCK-8比色法检测细胞存活率;应用碘化丙啶(PI)染色流式细胞术检测细胞凋亡率。结果应用不同浓度NaHS处理PC12细胞30 min,在50～400μmol.L-1浓度范围内,呈浓度依赖性地上调Akt磷酸化的水平,但随着NaHS浓度的增加,磷酸化Akt表达量逐渐下降;Ly294002明显抑制了NaHS对Akt磷酸化水平的上调作用。NaHS预处理可以保护PC12细胞对抗600μmol.L-1CoCl2诱导的损伤,使细胞存活率提高及细胞凋亡率降低。而在预处理前使用PI3K/Akt信号通路抑制剂Ly294002,则明显地减弱了H2S的神经细胞保护作用。结论 H2S可通过激活PI3K/Akt信号通路保护PC12细胞对抗化学性缺氧损伤。     

过表达THEM4对糖尿病小鼠肾脏细胞外基质沉积的影响

目的观察过表达硫酯酶超家族成员4(thioesterase superfamily member 4,THEM4)对糖尿病(diabetes mellitus,DM)小鼠肾脏细胞外基质(extracellular matrix,ECM)沉积的影响。方法将♂CD1小鼠随机分为4组:分别为正常对照组(Control组)、糖尿病组(DM组)、糖尿病+THEM4质粒组(DM+THEM4)、糖尿病+空质粒组(DM+V)。后3组腹腔注射链脲佐菌素(streptozotocin,STZ)诱发糖尿病小鼠模型,质粒注射组小鼠在成模4周后,分别给予尾静脉快速注射p Yr-ads-4-THEM4质粒或p Yr-adshuttle-4质粒(1 mg·kg^-1)。此后每隔7 d注射1次,共注射4次,之后处死小鼠并收集保存标本,Western blot检测THEM4、phospho-Akt(Ser 473)、TGF-β1、α-SMA的表达;免疫组化检测THEM4、phospho-Akt(Ser 473)、纤维黏连蛋白(fibronectin,FN)及Ⅲ型胶原(collagenⅢ,ColⅢ)蛋白表达和定位。结果DM小鼠肾脏THEM4 mRNA和蛋白均呈低表达,而phospho-Akt(Ser 473)、TGF-β1、α-SMA蛋白的表达明显增强,并出现ECM沉积。过表达的THEM4能够逆转DM小鼠肾脏phospho-Akt(Ser 473)蛋白活化,并下调α-SMA、TGF-β1的表达,减轻DM小鼠肾脏ECM的沉积,降低小鼠尿蛋白水平。结论过表达THEM4能够减轻DM小鼠肾脏ECM的沉积,可能是通过抑制phospho-Akt(Ser 473)蛋白的活化,下调α-SMA、TGF-β1表达而实现的。     

Notoginsenoside R1 attenuates cardiac dysfunction in endotoxemic mice: an insight into oestrogen receptor activation and PI3K/Akt signalling

Background and Purpose

Notoginsenoside R1 (NG-R1), a novel phytoestrogen isolated from Panax notoginseng, is believed to have anti-inflammatory, anti-oxidative and anti-apoptotic properties. However, its cardioprotective properties and underlying mechanisms are largely unknown. Here we have assessed the contribution of the anti-inflammatory effects of NG-R1 to the amelioration of septic cardiac dysfunction and inflammation in mice.

Experimental Approach

We assessed cardiac function in mice by echocardiography. We studied the protein or mRNA levels of some inflammatory factors, apoptotic factors and oestrogen receptors (ERs) in heart tissues upon stimulation with bacterial LPS, NG-R1 or some pharmacological inhibitors.

Key Results

Six hours after LPS administration (10 mg·kg⁻¹, i.p.) cardiac function was decreased, an effect attenuated by NG-R1 pretreatment (25 mg·kg⁻¹·d⁻¹, i.p.). NG-R1 also improved the imbalance between iNOS and eNOS, prevented activation of NF-κB and the subsequent myocardial inflammatory and apoptotic responses in endotoxemic mice. The effects of NG-R1 were closely associated with activation of the oestrogen receptor ERα and of PI3K/PKB (Akt) signalling, as characterized by NG-R1-induced preservation in ERα, phospho-Akt, phospho-GSK3β and I-κBα, and of cardiac function that was partially blocked by selective inhibitors of ERα or PI3K. However, NG-R1 had no effect on LPS-activated TLR-4.

Conclusions and Implications

NG-R1 is a promising compound for protecting the heart from septic shock, possibly via the activation of ERα and PI3K/Akt signalling. This mechanism produces blockade of NF-κB activation and attenuation of the pro-inflammatory state and apoptotic stress in the myocardium.     

姜黄素对人鼻咽癌株CNE-2Z细胞凋亡的影响及机制研究

目的探讨姜黄素(CU)对人鼻咽癌株CNE-2Z细胞凋亡的影响及机制。方法体外培养CNE-2Z细胞在梯度浓度CU(0、20、40、80μmol/L)干预48 h后,采用MTT法检测其对CNE-2Z抑制增殖的作用,ELISA法检测8-羟基-2-脱氧鸟苷(8-OHdG)水平,Hoechst33342染色检测细胞形态学的变化,Western blotting法检测PI3K和Akt磷酸化水平。结果与空白对照组(0μmol/L)比较,CU干预后明显抑制CNE-2Z的细胞增殖(P<0.01),同时减少内源性的8-OHdG生成(P<0.01)。此外,CU干预可有效促进癌细胞凋亡,下调p-PI3K和p-Akt的表达。结论姜黄素具有良好的抗肿瘤作用,其机制与抑制癌细胞增殖、诱导细胞凋亡及抑制PI3K/Akt通路有关。     

Additive effect of zinc oxide nanoparticles and isoorientin on apoptosis in human hepatoma cell line

Metal nanomaterial could effectively decrease tumour resistance to anti-cancer drugs. In this paper, we have explored the synergistic effect and mechanisms of zinc oxide nanoparticles (ZnO Nps) and isoorientin (ISO) on cytotoxicity in human hepatoma (HepG2) cells. The results showed that ZnO Nps could exert dose- and time-dependent cytotoxicity in HepG2 cells, and the combining treatment resulted in a greater cytotoxicity than single treatment. ZnO Nps could synergistically potentiate ISO to induce apoptosis through resulting in mitochondrial dysfunction, inhibiting the phosphorylation of Akt and ERK1/2, and enhancing the phosphorylation of JNK and P38. Additionally, ZnO Nps were uptaked by cells through endocytic pathway and it enhanced the cellular uptake of ISO, while no significant injury was found in normal liver cells after the combined treatment. These results suggest that the combination of metal nanoparticle with anti-cancer drugs may provide a promising alternative for novel cancer treatments.     

Reactive oxygen species and PI3K/Akt signaling play key roles in the induction of Nrf2-driven heme oxygenase-1 expression in sulforaphane-treated human mesothelioma MSTO-211H cells

The nuclear factor erythroid-derived 2 related factor 2 (Nrf2)/heme oxygenase (HO)-1 induction plays cytoprotective roles against oxidative injury, apoptosis, and anticancer therapy; however, little is known about its regulation in human mesothelioma MSTO-211H cells. In this study, we investigated Nrf2/HO-1 induction in response to sulforaphane and determined the signaling pathways involved in this process. Sulforaphane treatment decreased cell viability and triggered a rapid and transient increase in the intracellular ROS levels. Pretreatment with N-acetylcysteine (NAC) prevented sulforaphane-induced cytotoxicity. Erk1/2 was activated within 1h of sulforaphane addition, whereas Akt phosphorylation was suppressed until the first 8h, and was then maintained at an elevated level until 72h, displaying a biphasic regulatory feature. Nrf2 protein levels in both nuclear and whole cell lysates were increased after sulforaphane treatment and were decreased by pretreatment with NAC, actinomycin D and cycloheximide. Activation of the Nrf2/HO-1 system after sulforaphane treatment was suppressed by pretreatment with NAC or Ly294002, a PI3K inhibitor. Knockdown of Nrf2 with siRNA decreased cell viability and attenuated sulforaphane-induced HO-1 up-regulation. Overall, our results indicate that ROS generation and/or activation of PI3K/Akt signaling regulate cell survival and Nrf2-driven HO-1 expression in sulforaphane-treated MSTO-211H cells.     

Hyperoside induces both autophagy and apoptosis in non-small cell lung cancer cells in vitro

Aim:

Hyperoside (quercetin-3-O-β-D-galactopyranoside) is a flavonol glycoside found in plants of the genera Hypericum and Crataegus, which exhibits anticancer, anti-oxidant, and anti-inflammatory activities. In this study we investigated whether autophagy was involved in the anticancer mechanisms of hyperoside in human non-small cell lung cancer cells in vitro.

Methods:

Human non-small cell lung cancer cell line A549 was tested, and human bronchial epithelial cell line BEAS-2B was used for comparison. The expression of LC3-II, apoptotic and signaling proteins was measured using Western blotting. Autophagosomes were observed with MDC staining, LC3 immunocytochemistry, and GFP-LC3 fusion protein techniques. Cell viability was assessed using MTT assay.

Results:

Hyperoside (0.5, 1, 2 mmol/L) dose-dependently increased the expression of LC3-II and autophagosome numbers in A549 cells, but had no such effects in BEAS-2B cells. Moreover, hyperoside dose-dependently inhibited the phosphorylation of Akt, mTOR, p70S6K and 4E-BP1, but increased the phosphorylation of ERK1/2 in A549 cells. Insulin (200 nmol/L) markedly enhanced the phosphorylation of Akt and decreased LC3-II expression in A549 cells, which were reversed by pretreatment with hyperoside, whereas the MEK1/2 inhibitor U0126 (20 μmol/L) did not blocked hyperoside-induced LC3-II expression. Finally, hyperoside dose-dependently suppressed the cell viability and induced apoptosis in A549 cells, which were significantly attenuated by pretreatment with the autophagy inhibitor 3-methyladenine (2.5 mmol/L).

Conclusion:

Hyperoside induces both autophagy and apoptosis in human non-small cell lung cancer cells in vitro. The autophagy is induced through inhibiting the Akt/mTOR/p70S6K signal pathways, which contributes to anticancer actions of hyperoside.     

Urantide对大鼠心肌缺血/再灌注后心肌细胞凋亡的作用及机制研究

目的观察urantide对大鼠缺血/再灌注心肌组织氧化应激损伤的作用和心肌细胞凋亡的影响及其与PI3K/Akt及PKC信号通路的关系。方法可逆性冠脉左前降支结扎造成心肌缺血/再灌注模型,给予大鼠心脏缺血30 min再灌注90 min。80只大鼠随机分为假手术组、缺血/再灌注(I/R)组、urantide低、中、高剂量组(3,10,30μg.kg-1)、维拉帕米对照组(1.6 mg.kg-1)、urantide+CHE组(30μg.kg-1+1 mg.kg-1)、urantide+LY294002组(30μg.kg-1+0.3 mg.kg-1)。Urantide低、中、高剂量组中urantide于缺血前5 min舌下静脉1 min内一次性推注,urantide+CHE组与urantide+LY294002组中,在穿线稳定后舌下静脉分别快速推注CHE与LY294002,5 min后舌下静脉快速推注uran-tide 30μg.kg-1,稳定10 min后再行缺血/再灌注操作。实验结束后测定大鼠血清中超氧化物歧化酶(SOD)、一氧化氮合酶(NOS)活力和丙二醛(MDA)含量以及一氧化氮(NO)含量。TUNEL法检测凋亡细胞指数(AI),免疫组化法检测心肌组织Bcl-2、Bax的蛋白表达。结果与I/R组相比,urantide 30μg.kg-1能明显升高SOD活性(P<0.01),明显减少血清中MDA的含量(P<0.05),明显提高NOS活力(P<0.01),使NO含量增加(P<0.01);Bax蛋白表达和心肌细胞凋亡指数降低(P<0.01),Bcl-2蛋白表达增加(P<0.05);urantide+CHE组与urantide+LY294002组与urantide30μg.kg-1组相比,SOD活力和NO含量下降,MDA含量上升,心肌组织中Bax蛋白表达和心肌细胞凋亡指数上升,而Bcl-2蛋白表达下降,与I/R组比较差异无统计学意义(P>0.01)。结论 Urantide能够通过激活PKC和PI3K/Akt信号转导通路,减少心肌组织氧自由基的含量,进一步调控Bcl-2和Bax蛋白的表达,抑制心肌缺血/再灌注大鼠心肌细胞的凋亡,从而对大鼠心肌缺血/再灌注具有一定保护作用。     

迷迭香酸衍生物RAD-9通过PI3K/Akt和p38 MAPK信号通路诱导胃癌MGC-803细胞凋亡

目的研究迷迭香酸衍生物RAD-9诱导胃癌MGC-803细胞凋亡的作用及其机制。方法 MTT法观察RAD-9对胃癌MGC-803细胞增殖的抑制作用;流式细胞术检测细胞的凋亡;Hoechst 33258染色法观察RAD-9对MGC-803细胞核凋亡形态学的影响;Western blot检测RAD-9干预MGC-803细胞36 h后,对Akt、p-Akt、p38 MAPK、p-p38 MAPK蛋白及凋亡相关蛋白Bcl-2、Bax、caspase-3的影响。结果MTT结果显示,RAD-9呈时间、浓度依赖性抑制胃癌MGC-803细胞增殖;流式细胞术结果显示,RAD-9对胃癌MGC-803细胞有明显的促凋亡作用(P<0.01);Hoechst 33258染色实验结果显示,RAD-9干预胃癌MGC-803细胞36 h后,细胞核呈现典型凋亡形态学改变;Western blot结果显示,RAD-9干预胃癌MGC-803细胞36 h后,Bcl-2蛋白表达水平明显降低,Bax、caspase-3蛋白表达水平明显提高,Akt、p-Akt蛋白表达水平明显下调,p38 MAPK、p-p38 MAPK蛋白表达水平明显上调(P<0.01)。结论 RAD-9能抑制胃癌MGC-803细胞生长,且能诱导其凋亡,其机制可能与抑制PI3K/Akt和激活p38 MAPK信号通路相关。