Timosaponin AⅢ induces drug-metabolizing enzymes by activating constitutive androstane receptor (CAR) via dephosphorylation of the EGFR signaling pathway

The current study aimed to assess the effect of timosaponin AⅢ(T-AⅢ)on drug-metabolizing enzymes during anticancer therapy.The in vivo experiments were conducted on nude and ICR mice.Following a 24-day administration of T-AⅢ,the nude mice exhibited an induction of CYP2B10,MDR1,and CYP3A11 expression in the liver tissues.In the ICR mice,the expression levels of CYP2B10 and MDR1 increased after a three-day T-AⅢ administration.The in vitro assessments with HepG2 cells revealed that T-AⅢ induced the expression of CYP2B6,MDR1,and CYP3A4,along with constitutive androstane receptor(CAR)activation.Treatment with CAR siRNA reversed the T-AⅢ-induced increases in CYP2B6 and CYP3A4 expression.Furthermore,other CAR target genes also showed a significant increase in the expression.The up-regulation of murine CAR was observed in the liver tissues of both nude and ICR mice.Subsequent findings demonstrated that T-AⅢ activated CAR by inhibiting ERK1/2 phosphorylation,with this effect being partially reversed by the ERK activator t-BHQ.Inhibition of the ERK1/2 signaling pathway was also observed in vivo.Additionally,T-AⅢ inhibited the phosphorylation of EGFR at Tyr1173 and Tyr845,and suppressed EGF-induced phosphorylation of EGFR,ERK,and CAR.In the nude mice,T-AⅢ also inhibited EGFR phosphorylation.These results collectively indicate that T-AⅢ is a novel CAR activator through inhibition of the EGFR pathway.

Acupuncture at Back-Shu point improves insomnia by reducing inflammation and inhibiting the ERK/NF-κB signaling pathway

BACKGROUND Insomnia is a disease where individuals cannot maintain a steady and stable sleep state or fail to fall asleep.Western medicine mainly uses sedatives and hypnotic drugs to treat insomnia,and long-term use is prone to drug resistance and other adverse reactions.Acupuncture has a good curative effect and unique advantages in the treatment of insomnia.AIM To explore the molecular mechanism of acupuncture at Back-Shu point for the treatment of insomnia.METHODS We first prepared a rat model of insomnia,and then carried out acupuncture for 7 consecutive days.After treatment,the sleep time and general behavior of the rats were determined.The Morris water maze test was used to assess the learning ability and spatial memory ability of the rats.The expression levels of inflammatory cytokines in serum and the hippocampus were detected by ELISA.qRTPCR was used to detect the mRNA expression changes in the ERK/NF-κB signaling pathway.Western blot and immunohistochemistry were carried out to evaluate the protein expression levels of RAF-1,MEK-2,ERK1/2 and NF-κB.RESULTS Acupuncture can prolong sleep duration,and improve mental state,activity,diet volume,learning ability and spatial memory.In addition,acupuncture increased the release of 1L-1β,1L-6 and TNF-αin serum and the hippocampus and inhibited the mRNA and protein expression of the ERK/NF-κB signaling pathway.CONCLUSION These findings suggest that acupuncture at Back-Shu point can inhibit the ERK/NF-κB signaling pathway and treat insomnia by increasing the release of inflammatory cytokines in the hippocampus.

Immunoregulatory polysaccharides from Apocynum venetum L.flowers stimulate phagocytosis and cytokine expression via activating the NF-κB/MAPK signaling pathways in RAW264.7 cells

Two immunomodulatory polysaccharides(Vp2a-Ⅱ and Vp3) were isolated and identified from Apocynum venetum L. flowers, and their innate immune-stimulating functions and working mechanisms were evaluated in RAW264.7 cells. Both the level of released nitric oxide(NO) and expression of inducible nitric oxide synthase(iNOS) m RNA were significantly enhanced in the RAW264.7 macrophages cells treated by Vp2a-Ⅱ and Vp3. Vp2a-Ⅱ(100–800 μg/m L) and Vp3(400 μg/mL) could significantly increase the phagocytic activity of RAW264.7 cells and the secretion and m RNA expression of TNF-α and IL-6 in a concentrationdependent manner through affecting mitogen-activated protein kinase(MAPK) activity and nuclear factor κB(NF-κB) nuclear translocation. Vp2a-Ⅱ might activate the MAPK signaling pathways and induce the nuclear translocation of NF-κB p65, whilst Vp3 likely activated the NF-κB and MAPK signaling pathways without influencing the p38 MAPK route.

BcSDR1 is involved in regulation of glucose transport and cAMP and MAPK signaling pathways in Botrytis cinerea

Botrytis cinerea is a typical necrotrophic pathogenic fungus that causes severe diseases in a wide range of plant species, leading to significant economic losses. Our previous study showed that BcSDR1 positively regulates growth,development, and pathogenicity of B. cinerea. However, the regulation mechanism of BcSDR1 and the relationship between BcSDR1 and cAMP and MAPK signaling pathways are not well understood. In this study, transcriptome data showed that BcSDR1 is involved in glucose transmembrane transport, signal transduction, secondary metabolism, and other biological processes. BcSDR1 mutant(BCt41) showed remarkably weak sensitivity to cAMP and MAPK signaling pathways specific inhibitors, SQ22536 and U0126, and significantly decreased cAMP content. The key genes of cAMP and MAPK signaling pathways, BcGB1, BcBTP1, BcBOS1, BcRAS1, and BcBMP3 were significantly upregulated,whereas BcPLC1, BcBCG1, BcCDC4, BcSAK1, BcATF1, and BcBAP1 were significantly downregulated(P<0.05).BcSDR1 was obviously upregulated in BcBCG2, BcBCG3, BcPKA1, and BcPKAR RNA interference(RNAi) mutants, but significantly downregulated in BcPKA2, BcBMP1, and BcBMP3 RNAi mutants. Thus, BcBCG2, BcBCG3, BcPKA1, and BcPKAR negatively regulate BcSDR1 expression, whereas BcPKA2, BcBMP1, and BcBMP3 positively regulate BcSDR1expression.

丹参多糖经MAPK/ERK信号轴抑制对肺癌细胞A549增殖、迁移和凋亡的影响

目的 探讨丹参多糖经丝裂原激活蛋白激酶(MAPK)/细胞外信号调节激酶(ERK)信号轴抑制对肺癌细胞A549增殖、迁移和凋亡的影响。方法 体外培养A549细胞,用不同质量浓度(0,1,2,4,8,16,32,64 mg/mL)丹参多糖干预48 h后,确定丹参多糖的半数抑制浓度(IC50);将A549细胞分为对照组、高剂量组、中剂量组和低剂量组(分别以0,8,4,2 mg/mL丹参多糖干预),以及抑制剂组(40μmol/L PD 98059)。采用划痕愈合试验检测A549细胞的迁移水平,采用流式细胞术检测A549细胞的凋亡情况,同时采用实时荧光定量聚合酶链反应法和免疫印迹法分别检测A549细胞中MAPK、ERK、基质金属蛋白酶-9(MMP-9)、B细胞淋巴瘤2基因(Bcl-2)、胱天蛋白酶3(caspase-3)mRNA和蛋白表达水平。结果 随着丹参多糖质量浓度的增加,A549细胞增殖率显著降低(P <0.05);丹参多糖对A549细胞的IC50为7.82 mg/mL,高、中、低剂量组干预剂量分别为8,4,2 mg/mL。与对照组比较,抑制剂组,高、中、低剂量组细胞的迁移距离及MMP-9,MAPK,ERK,Bcl-2 mRNA和蛋白表达水平均显著降低(P <0.05),细胞凋亡率、caspase-3 mRNA和蛋白表达水平均显著升高(P <0.05);与抑制剂组比较,高、中、低剂量组细胞的迁移距离及MMP-9,MAPK,ERK,Bcl-2 mRNA和蛋白表达水平均显著升高(P <0.05),细胞凋亡率、caspase-3 mRNA和蛋白表达水平均显著降低(P <0.05),且随丹参多糖剂量的增加呈量效依赖关系(P <0.05)。结论 丹参多糖可能通过MAPK/ERK信号轴诱导A549细胞凋亡,抑制A549细胞增殖和迁移。

Experimental study on the effect of cryoablation on lung cancer mice based on MAPK/ERK signaling pathway

Objective:To study the regulatory effect of cryoablation on MAPK/ERK signaling pathway in mice with lung adenocarcinoma.Methods:Lewis mouse lung adenocarcinoma cell line was used to establish subcutaneous transplanted tumor model in C57BL/6 mice.Ten mice were randomly divided into two groups:sham operation group and cryoablation group,with 5 mice in each group.The cryoablation group was treated with double circulation-rewarming ablation,and the sham operation group was treated with incision and suture at the transplanted tumor.The tumor tissues were taken 14 days after operation.Detect the effect of cryoablation on MAPK/ERK pathway related proteins by Western blot,such as KRAS,RAF1,MEK1,ERK1/2,P-RAF1,P-MEK1,P-ERK1/2.The expression of KRAS gene was further verified by qRt-PCR.Results:Compared with the sham operation group,the phosphorylated proteins P-RAF1,P-MEK1 and P-ERK1/2 in tumor tissue after cryoablation were decreased(P<0.05),and the key molecule KRAS in MAPK/ERK pathway was decreased in protein and gene expression(P<0.05).Conclusion:Cryoablation can negatively regulate MAPK/ERK signaling pathway by down-regulating KRas expression.

Maleylated-BSA induces TNF-α production through the ERK and NF-κB signaling pathways in murine RAW264.7 macrophages

Ligands for macrophage scavenger receptors are reported to induce a wide range of host cell responses, including the production of inflammatory cytokines;however, the underlying mechanisms have not yet been fully understood and which remain obscure. In this study, we have examined the effect of maleylated bovine serum albumin (maleylated-BSA), a well-known ligand of the scavenger receptor, on the murine macrophage cell line RAW264.7. Maleylated-BSA strongly induced the production of tumor necrosis factor-α (TNF-α) and induced phosphorylation of extracellular signal-regulated kinase (ERK) and NF-kB p65. We also observed that maleylated-BSA-induced TNF-α production was blocked by the ERK inhibitor U0126. Together, these data demonstrates that maleylated-BSA- induced production of TNF-α requires the ERK/NF-κB signaling cascade in murine RAW- 264.7 macrophages.

欧前胡素调节ERK/MAPK信号通路对肺结核大鼠炎症反应的影响

目的 探讨欧前胡素(Imp)调节细胞外调节蛋白激酶(ERK)/有丝分裂原激活蛋白激酶(MAPK)信号通路对肺结核大鼠炎症反应的影响。方法 64只大鼠随机分为对照组12只及造模组52只,造模组大鼠通过尾部注射结核杆菌方法建立肺结核大鼠模型,之后随机分为模型组、Imp低(Imp-L,25 mg/kg)、中(Imp-M,50 mg/kg)、高剂量(Imp-H,100 mg/kg)组、Imp-H+ERK特异性激活剂(EGF,100 mg/kg Imp+25 mg/kg EGF)组。干预结束后,主动脉采血,ELISA检测各组大鼠血清中白细胞介素-6(IL-6)、γ干扰素(IFN-γ)、环氧化酶-2(COX-2)水平;分离肺组织,HE、Tunel分别检测大鼠肺组织病理学变化及细胞凋亡情况;统计肺组织中结核杆菌菌落数;Western blot检测p-ERK1/2/ERK1/2、p38 MAPK表达水平。结果 与对照组相比,模型组肺组织严重病变,IL-6、IFN-γ、COX-2、细胞凋亡率、结核杆菌菌落数、p-ERK1/2/ERK1/2、p38 MAPK表达均显著增加(P<0.05);与模型组相比,Imp-L组、Imp-M组、Imp-H组病理损伤得到缓解,IL-6、IFN-γ、COX-2、细胞凋亡率、结核杆菌菌落数、p-ERK1/2/ERK1/2、p38 MAPK表达显著降低,以Imp-H组变化最为显著(P<0.05);与Imp-H组相比,Imp-H+EGF组病理损伤进一步加重,IL-6、IFN-γ、COX-2、细胞凋亡率、结核杆菌菌落数、p-ERK1/2/ERK1/2、p38 MAPK表达显著增加(P<0.05)。结论 Imp可降低肺结核炎症反应,与抑制ERK/MAPK信号通路的激活有关。

mTOR和ERK/MAPK信号通路调控自噬在孤独症发病中的作用

孤独症是一种以重复刻板样行为和社交缺陷为主要特征的神经发育障碍性疾病,发病率高的特点使其逐渐成为研究的热点。中国与西方国家孤独症的发病率相似,约为1%,位于儿童精神疾病的前列^([1])。目前认为孤独症由环境和遗传因素共同决定,病因复杂,具体机制尚不明确。随着研究的深入,自噬在孤独症发病机制中的作用受到广泛关注。

锌指蛋白-36缺陷抑制小鼠的成骨细胞分化:基于激活ERK/ MAPK通路

目的探究锌指蛋白-36(ZFP36)对成骨细胞分化的调控作用及机制。方法通过提取小鼠原代骨髓间充质干细胞,结合小鼠成骨细胞前体细胞系MC3T3-E1,在体外成骨分化诱导状态下观察Zfp36(编码ZFP36)的表达变化。通过干扰RNA技术构建Zfp36缺陷的细胞,观察成骨分化作用的改变。通过第二代转录组测序技术探究Zfp36缺陷细胞成骨分化过程中的转录组水平改变。通过ERK/MAPK信号抑制分子U0126验证Zfp36缺陷对成骨分化作用的调控机制。结果小鼠原代骨髓间充质细胞以及MC3T3-E2细胞中Zfp36表达在成骨分化0~14d过程中呈逐渐升高趋势,在第7天到达峰值时较第0天升高3.85倍(P<0.0001)。抑制上述细胞Zfp36的表达后,成骨分化过程中碱性磷酸酶染色及茜素红染色弱于对照组,成骨分化标志基因Alpl(P<0.01)、Sp7(P<0.001)、Bglap(P<0.01)、Ibsp(P<0.0001)表达显著减弱。转录本测序结果提示Zfp36缺陷细胞的下调基因富集到骨矿化相关基因集中,且与ERK信号相关。蛋白表达检测显示Zfp36缺陷细胞的磷酸化ERK蛋白比例较对照组升高2.1倍(P=0.0274)。通过分子化合物U0126抑制Zfp36缺陷细胞中被激活的ERK/MAPK信号,可观察到表型挽救现象,并且呈剂量依赖。Zfp36缺陷细胞在10μmol/L度U0126作用下碱性磷酸酶染色增强,成骨细胞分化标志基因Runx2(P<0.05)及Bglap(P<0.05)表达显著增高。结论ZFP36参与了小鼠成骨细胞的分化调控过程,Zfp36缺陷会引起ERK/MAPK信号通路的激活,进而抑制成骨细胞向骨细胞的分化。

Effect of ginsenoside Rg1 on hematopoietic stem cells in treating aplastic anemia in mice via MAPK pathway

BACKGROUND Aplastic anemia(AA)presents a significant clinical challenge as a life-threatening condition due to failure to produce essential blood cells,with the current the-rapeutic options being notably limited.AIM To assess the therapeutic potential of ginsenoside Rg1 on AA,specifically its protective effects,while elucidating the mechanism at play.METHODS We employed a model of myelosuppression induced by cyclophosphamide(CTX)in C57 mice,followed by administration of ginsenoside Rg1 over 13 d.The invest-igation included examining the bone marrow,thymus and spleen for pathological changes via hematoxylin-eosin staining.Moreover,orbital blood of mice was collected for blood routine examinations.Flow cytometry was employed to identify the impact of ginsenoside Rg1 on cell apoptosis and cycle in the bone marrow of AA mice.Additionally,the study further evaluated cytokine levels with enzyme-linked immunosorbent assay and analyzed the expression of key proteins in the MAPK signaling pathway via western blot.RESULTS Administration of CTX led to significant damage to the bone marrow’s structural integrity and a reduction in hematopoietic cells,establishing a model of AA.Ginsenoside Rg1 successfully reversed hematopoietic dysfunction in AA mice.In comparison to the AA group,ginsenoside Rg1 provided relief by reducing the induction of cell apoptosis and inflammation factors caused by CTX.Furthermore,it helped alleviate the blockade in the cell cycle.Treatment with ginsenoside Rg1 significantly alleviated myelosuppression in mice by inhibiting the MAPK signaling pathway.CONCLUSION This study suggested that ginsenoside Rg1 addresses AA by alleviating myelosuppression,primarily through modulating the MAPK signaling pathway,which paves the way for a novel therapeutic strategy in treating AA,highlighting the potential of ginsenoside Rg1 as a beneficial intervention.

铜离子激活MAPK-ERK通路调控鼻咽癌放射敏感性

目的探究铜离子(Cu^(2+))对鼻咽癌(nasopharyngeal carcinoma,NPC)细胞放射敏感性的影响,寻找提升NPC放疗效果的潜在靶标。方法细胞Cu^(2+)检测对比正常鼻咽上皮细胞系NP69及多种NPC细胞系内Cu^(2+)的含量;分别加入0、5、10、20、50、100、200μmol/L Cu^(2+)溶液及0、0.05、0.1、0.2、0.5、1.0、2.0 mmol/L TEPA溶液,利用CCK-8实验测定NPC细胞内Cu^(2+)含量对辐照前后细胞存活率的影响,并确定后续实验中Cu^(2+)组及TEPA组所使用的药物浓度;CCK-8实验及克隆形成实验检测药物处理后各组NPC细胞放射敏感性的变化;Western blot检测各组NPC细胞辐照处理前后的DNA损伤情况及MAPK-ERK通路相关蛋白表达。结果NPC细胞中Cu^(2+)含量显著高于正常鼻咽上皮细胞(P<0.05)。添加Cu^(2+)溶液浓度低于50μmol/L时促进CNE1细胞的放疗抵抗性,添加0.1~0.2 mmol/L TEPA能提高SUNE1细胞放射敏感性(P<0.05)。与对照组比较,Cu^(2+)组NPC细胞放疗抵抗性增强,TEPA组NPC细胞放疗敏感性增强(P<0.05)。较之对照组而言,Cu^(2+)组细胞MAPK-ERK通路活化程度上调(P<0.05)。使用MAPK-ERK通路抑制剂SCH772984能够有效逆转Cu^(2+)介导的NPC放疗抵抗(P<0.05)。结论NPC细胞中Cu^(2+)含量升高,其通过激活MAPK-ERK通路增强NPC细胞的放疗抵抗性。

基于MAPK/ERK信号通路探讨孟鲁司特通过自噬改善哮喘模型小鼠肺损伤的机制

目的探究孟鲁司特是否可改善哮喘小鼠肺损伤,并基于丝裂原活化蛋白激酶(MAPK)/细胞外信号调节蛋白激酶(ERK)信号通路介导的自噬探究其改善肺损伤的机制。方法选取60只无特定病原体(SPF)级BALB/c小鼠:对照组、哮喘组、孟鲁司特组及司美替尼(Selumetinib)组,每组15只。肺功能仪检测小鼠第0.15秒用力呼气容积(FEV_(0.15))、最高呼气流速(PEF)。苏木素-伊红(HE)染色检测小鼠肺组织病理学形态。Masson染色检测肺组织平滑肌增生与胶原沉积水平。Western blotting检测肺组织中MAPK、ERK、Beclin1及微管相关蛋白轻链3(LC3Ⅱ)蛋白水平。免疫组织化学检测肺组织中MAPK、ERK蛋白水平。结果与对照组比较,哮喘组小鼠FEV_(0.15)、PEF均降低,差异均有统计学意义(P<0.05);与哮喘组比较,孟鲁司特组FEV_(0.15)、PEF均增加,差异均有统计学意义(P<0.05)。HE染色结果显示,哮喘组小鼠可见支气管壁增厚、炎性浸润显著等病理学形态损伤;孟鲁司特组可见肺组织病理学形态损伤改善。Masson染色结果显示,哮喘组小鼠支气管平滑肌增厚,且其周围可见胶原大量沉积;孟鲁司特组小鼠支气管平滑肌增生减轻,周围胶原沉积减少。Western blooting检测结果显示,与对照组比较,哮喘组小鼠肺组织中MAPK、ERK、Beclin1、LC3Ⅱ表达水平增加,差异均有统计学意义(P<0.05);与哮喘组比较,孟鲁司特组小鼠肺组织中MAPK、ERK、Beclin1、LC3Ⅱ表达水平降低,差异均有统计学意义(P<0.05)。与对照组比较,哮喘组小鼠FEV_(0.15)、PEF降低,MAPK、ERK、Beclin1、LC3Ⅱ蛋白表达水平均增加,差异均有统计学意义(P<0.05)。与哮喘组比较,Selumetinib组FEV_(0.15)、PEF均增加,MAPK、ERK、Beclin1、LC3Ⅱ蛋白表达水平均降低,差异均有统计学意义(P<0.05)。结论孟鲁司特可改善哮喘小鼠肺损伤,其机制可能与MAPK/ERK信号通路介导的自噬相关。

老年冠心病患者PCI术后心肌再灌注损伤与ERK/MAPK信号通路的相关性

目的探讨老年冠状动脉粥样硬化性心脏病(冠心病)患者经皮冠状动脉介入治疗(PCI)术后心肌再灌注损伤的影响因素及与细胞外调节蛋白激酶/丝裂原活化蛋白激酶(ERK/MAPK)信号通路活化的相关性。方法选择2020年3月至2022年12月于郑州大学附属郑州中心医院心血管内科92例行PCI的老年冠心病患者作为研究对象,采用实时荧光定量PCR检测患者术前ERK、p38-MAPK mRNA的表达,评估PCI术后心肌再灌注损伤情况,分析其影响因素及与ERK/MAPK信号通路指标的关系。结果92例患者中20例(21.74%)PCI术后出现心肌再灌注损伤(损伤组,n=20)。损伤组患者PCI术前血流分级≤2级、Killip分级≥2级比例显著高于非损伤组患者,术前血清ERK、p38-MAPK mRNA表达量高于非损伤组,差异有统计学意义(P<0.05)。多因素回归分析示,术前血流分级≤2级、Killip分级≥2级及血清ERK、p38-MAPK水平升高是老年冠心病患者PCI术后出现心肌再灌注损伤的影响因素(P<0.05)。结论除血流分级、Killip分级外,术前ERK/MAPK信号通路相关指标高表达可增加老年冠心病患者PCI术后心肌再灌注损伤风险,临床应予以密切监测,以尽早识别心肌再灌注损伤并采取针对性干预措施。

基于MAPK/ERK/NF-κB信号通路探讨中西医结合治疗原发性痛经的研究进展

痛经(Dysmenorrhea)是临床常见妇科疾病,中医亦称“经行腹痛”,是指女性在行经前后或月经期,下腹部出现痉挛性疼痛,亦可放射至腰骶部,伴或不伴有恶心呕吐、腹泻及头晕乏力等全身症状。痛经可分为原发性和继发性两类,其中原发性痛经指生殖器官无器质性病变者;继发性痛经则是由于盆腔器质性疾病,如子宫内膜异位症、子宫腺肌症、子宫肌瘤、盆腔炎或宫颈狭窄等引起者。目前西医治疗原发性痛经多以解痉止痛的药物治疗,疗效虽显著而快速,但是副作用较大,停药后易复发;而中医在临床上四诊合参,辨证论治,不仅可以标本同治,也有助于预防调摄。通过梳理归纳近10年国内外原发性痛经的文献资料,基于MAPK/ERK/NF-κB信号通路探析原发性痛经的中西医研究进展,以期为中医药防治原发性痛经提供理论依据。现将原发性痛经的研究现状综述如下。

NIMA related kinase 2 promotes gastric cancer cell proliferation via ERK/MAPK signaling

BACKGROUND NIMA related kinase 2(NEK2) is closely related to mitosis, and it is currently considered to be over-expressed frequently in many poorly prognostic cancers.However, the effect of the up-regulated NEK2 on cellular signaling in tumors,such as gastric cancer(GC), is con-fusing.AIM To determine the role of the up-regulation of NEK2 in GC.METHODS To investigate the pathological significance of NEK2 in GC, the expression pattern of NEK2 in GC was investigated based on the 'Oncomain' database and compared between 30 pairs of cancer samples and adjacent tissues. The coexpression of NEK2 and ERK in GC was analyzed using The Cancer Genome Atlas(TCGA) database and confirmed in clinical samples by quantitative realtime PCR(qRT-PCR), and the survival curve was also plotted. Western blot or qRT-PCR was used to analyze the effect of NEK2 on the phosphorylation levels of ERK and c-JUN in two GC cell lines(BGC823 and SGC7901) with NEK2 overexpression, and the expression of the downstream effector cyclin D1.Furthermore, CCK8, EdU incorporation assay, and flow cytometry were used to detect the proliferative ability of BGC823 and SGC7901 cells with stably silenced ERK.RESULTS NEK2 was significantly up-regulated in human GC tissues. ERK was significantly associated with NEK2 expression in human clinical specimens, and combined overexpression of NEK2 and ERK potentially forecasted a poor prognosis andsurvival in GC patients. NEK2 knockdown in GC cells inhibited ERK and c-JUN phosphory-lation and reduced the transcription of cyclin D1. More interestingly,NEK2 can rescue the inhibition of cellular viability, proliferation, and cell cycle progression due to ERK knockdown.CONCLUSION Our results indicate that NEK2 plays a carcinogenic role in the malignant proliferation of GC cells via the ERK/MAPK signaling, which may be important for treatment and improving patient survival.

Estrogen and insulin synergistically promote endometrial cancer progression via crosstalk between their receptor signaling pathways

Objective: Despite evidence that estrogens and insulin are involved in the development and progression of many cancers, their synergistic role in endometrial carcinoma(EC) has not been analyzed yet.Methods: Here, we investigated how estrogens act synergistically with insulin to promote EC progression. Cell growth in vitro and in vivo, effects of estradiol and insulin on apoptosis and cell cycle distribution, and expression and activation of estrogen receptor(ER), insulin receptor(InsR), and key proteins in the PI3K and MAPK pathways were examined after combined stimulation with estradiol and insulin.Results: Compared to EC cells treated with estradiol or insulin alone, those treated with both estradiol and insulin exhibited stronger stimulation. Estradiol significantly induced phosphorylation of InsR-β and IRS-1, whereas insulin significantly induced phosphorylation of ER-α. In addition, treatment with both insulin and estradiol together significantly increased the expression and phosphorylation of Akt, MAPK, and ERK. Notably, InsR-β inhibition had a limited effect on estradiol-dependent proliferation,cell cycle, and apoptosis, whereas ER-α inhibition had a limited insulin-dependent effect, in EC cell lines. Insulin and estradiol individually and synergistically promoted EC xenograft growth in mice.Conclusions: Estrogen and insulin play synergistic roles in EC carcinogenesis and progression by activating InsR-β and ER-α,promoting a crosstalk between them, and thereby resulting in the activation of downstream PI3K/Akt and MAPK/ERK signaling pathways.

Endogenous hydrogen sulfide and ERK1/2-STAT3 signaling pathway may participate in the association between homocysteine and hypertension

Background Homocysteine(Hcy)is a risk factor for hypertension,although the mechanisms are poorly understood.Methods We first explored the relationship between Hcy levels and blood pressure(BP)by analyzing the clinical data of primary hypertensive patients admitted to our hospital.Secondly,we explored a rat model to study the effect of Hcy on blood pressure and the role of H2S.An hyperhomocysteinemia(HHcy)rat model was induced to explore the effect of Hcy on blood pressure and the possible mechanism.We carried out tissue histology,extraction and examination of RNA and protein.Finally,we conducted cell experiments to determine a likely mechanism through renin-angiotensin-aldosterone system(RAAS)and extracellular signal-regulated kinase 1/2(ERK1/2)signaling pathway.Results In primary hypertensive inpatients with HHcy,blood pressure was significantly higher as compared with inpatient counterparts lacking HHcy.In the rat model,blood pressure of the Wistar rats was significantly increased with increases in serum Hcy levels and decreased after folate treatment.Angiotensin converting enzyme 1(ACE1)expression in the Wistar Hcy group was enhanced comparing to controls,but was decreased in the Wistar folate group.Angiotensin II receptor type 1(AGTR1)levels in the kidney tissue increased in the Wistar folate group.Both serum H2S and kidney cystathionineγ-lyase decreased with elevated levels of serum Hcy.In vitro,increased concentrations and treatment times for Hcy were associated with increased expression of collagen type 1 and AGTR1.This dose and time dependent response was also observed for p-STAT3 and p-ERK1/2 expression.Conclusion Endogenous H2S might mediate the process of altered blood pressure in response to changes in serum Hcy levels,in a process that is partly dependent on activated RAAS and ERK1/2-STAT3 signaling pathway.

MEK/ERK signaling pathway in apoptosis of SW620 cell line and inhibition effect of resveratrol

Objective:To study the involvement of MAPK MEK/ERK signaling transduction pathway in the apoptosis process of SW620 tumor cell line and the inhibition effect of resveratrol.Methods:SW620 cell lines were divided into 5 groups,namely,control group.PD98059 group,low-dose resveratrol group,mid-dose resveratrol group and high-dose resveratrol group.The inhibition rate of cell proliferation was detected by MTT method.The expression of apoptotic molecules and MEK/ERK signaling pathway related proteins were assayed by realtime PCR and Western blotting.Results:Compared with control group,the proliferation of cells treated with resveratrol was significantly inhibited.In the case of apoptotic molecules,the expression of Bax,Caspase 3 and Caspase 9 was increased significantly while the expression of anti-apoptotic molecule Bcl2 was decreased significantly in resveratrol groups with a dosedependent manner.In the case of molecules in MEK/ERK signaling pathway,the expression of Ras,Raf,MEK and ERKl/2 was decreased significantly in resveratrol groups with a dose-dependent manner.Conclusions:PD98059 and resveratrol can effectively inhibit the proliferation of SW620 through inhibiting the MEK/ERK signaling pathway.

Nucleolin Mediates LPS-induced Expression of Inflammatory Mediators and Activation of Signaling Pathways

Summary:In this study,we investigated the effects of nucleolin on lipopolysaccharide(LPS)-induced activation of MAPK and NF-KappaB(NF-kB)signaling pathways and secretion of TNF-a,IL-1βand HMGB1 in THP-1 monocytes.Immunofluorescence assay and Western blotting were used to identify the nucleolin expression in cell membrane,cytoplasm and nucleus of THP-1 monocytes.Inactivation of nucleolin was induced by neutralizing antibody against nucleolin.THP-1 monocytes were pretreated with anti-nucleolin antibody for 1 h prior to LPS challenge.The irrelevant IgG group was used as control.Secretion of inflammatory mediators(TNF-a,IL-1β and HMGB1)and activation of MAPK and NF-kB/I-kB signaling pathways were examined to assess the effects of nucleolin on LPS-mediated inflammatory response.Nucleolin existed in cell membrane,cytoplasm and nucleus of THP-1 monocytes.Pretreatment of anti-nucleolin antibody significantly inhibited the LPS-induced secretion of TNF-a,IL-1β and HMGB1.P38,JNK,ERK and NF-κB subunit p65 inhibitors could significantly inhibit the secretion of IL-1β,TNF-a and HMGB1 induced by LPS.Moreover,the phosphorylation of p38,JNK,ERK and p65(or nuclear translocation of p65)was significantly increased after LPS challenge.In contrast,pretreatment of anti-nucleolin antibody could significantly inhibit the LPS-induced phosphorylation of p38,JNK,ERK and p65(or nuclear translocation of p65).However,the irrelevant IgG,as a negative control,had no effect on LPS-induced secretion of TNF-a and IL-Iβ and phosphorylation of p38,JNK,ERK and p65(or nuclear translocation of p65).We demonstrated that nucleolin mediated the LPS-induced activation of MAPK and NF-κB signaling pathways,and regulated the secretion of inflammatory mediators(TNF-a,IL-1β and HMGB1).