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.

Longan Aril Reverses H2O2 Cytotoxicity in PC12 Cells via RAS/MEK/ERK Signaling Pathway

[Objectives]To explore the neuroprotective effects and mechanism of Longan Aril(LA)effective parts on PC12 cells injured by H2O2.[Methods]The neuroprotective effects of LA were evaluated by the cell viability,SOD and MDA content,apoptosis assay and relative protein expression of Aβand p-Tau.The neuroprotective mechanism of LA was studied by using metabolomics and network pharmacology,and the expressions of RAS/MEK/ERK signaling pathway-related proteins were detected by western blotting.[Results]LA could improve the cell survival rate and SOD content,and reduce apoptosis and expression of Aβand p-tau.Inhibition of RAS/MEK/ERK signaling pathway is a possible mechanism of LA neuroprotective effects.[Conclusions]LA has a neuroprotective effects in vitro and be likely to inhibit the process of AD by inhibition of RAS/MEK/ERK signalling pathway.

TRAF3IP3 at the trans-Golgi network regulates NKT2 maturation via the MEK/ERK signaling pathway

Thymic natural killer T(NKT)2 cells are a subset of invariant NKT cells with PLZF^(hi)GATA3^(hi)IL-4^(+).The differentiation of NKT2 cells is not fully understood.In the present study,we report an important role of TRAF3-interacting protein 3(TRAF3IP3)in the functional maturation and expansion of committed NKT2s in thymic medulla.Mice with T-cell-specific deletion of TRAF3IP3 had decreased thymic NKT2 cells,decreased IL-4-producing peripheral iNKTs,and defects in response toα-galactosylceramide.Positive selection and high PLZF expression in CD24^(+)CD44^(−) and CCR7^(+)CD44^(−) immature iNKTs were not affected.Only CD44^(hi)NK1.1^(−) iNKTs in Traf3ip3^(−/−) mice showed reduced expression of Egr2,PLZF,and IL-17RB,decreased proliferation,and reduced IL-4 production upon stimulation.This Egr2 and IL-4 expression was augmented by MEK1/ERK activation in iNKTs,and TRAF3IP3 at the trans-Golgi network recruited MEK1 and facilitated ERK phosphorylation and nuclear translocation.LT βR-regulated bone marrow-derived nonlymphoid cells in the medullary thymic microenvironment were required for MEK/ERK activation and NKT2 maturation.These data demonstrate an important functional maturation process in NKT2 differentiation that is regulated by MEK/ERK signaling at the trans-Golgi network.

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.

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.

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.

The role of ERK1/2 signaling pathway in coronary microembolization-induced rat myocardial inflammation and injury

Objectives In this work,we explore the effect of atorvastatin on myocardial apoptosis and caspase-8 acti- vation after coronary microembolization(CME) in rats. Methods Fifty rats were randomly divided into five groups; the coronary microembolization(CME) group,the sham-operated (sham) control group,the gastric lavage control group, the atorvastatin lavage group,and the caspasse-8 inhibitor (N-acetyl-Ile-Glu-Thr-Asp-CHO,abbreviated as CHO) group,with 10 rats for each group.A microembolization ball was injected through the left ventricle for constructing the CME model.Animals in the sham control group were given an injection of physiological saline instead of the microembolization ball.Seven days before the operation,the atorvastatin group underwent gastric lavage with 20 mg/kg of atorvastatin once a day.Gastric lavage control animals underwent gastric lavage with an equivalent dose of physiological saline instead of the atorvastatin.Animals in the CHO group were given an intraperitoneal injection of 10 mg/kg of CHO 30 min before the operation.Six hours after the operation,cardiac ultrasonic detection was conducted on each group to measure the cardiac function indexes.TUNEL(Terminal-deoxynucleoitidyl transferase mediated dUTP nick end labeling) assays were used to measure myocardial apoptosis,and western blots were used to quantify the expression levels of activated caspase-3 and -8.Results(1) The echocardiographic parameters showed that,compared to the sham control animals,the left ventricular ejection fraction(LVEF) of the CME group was significantly decreased(P【0.05).In addition, cardiac sonography revealed a decrease in the left ventricular shortening fraction(FS) and cardiac output(CO), but an increase in the left ventricular end-diastolic dimension (LVEDd).Compared to the CME group,the atorvastatin and CHO groups exhibited significantly improved cardiac function (P【0.05).(2) When compared with the sham control,the myocardical apoptotic rate of the CME group,as well as the levels of activated caspase-3 and-8,increased significantly (P【0.05).The myocardial apoptotic rate,as well as the levels of activated caspase-3 and caspase-8 in the atorvastatin and CHO groups,decreased significandy(P【0.05) in comparison to the CME group.Conclusions The atorvastatin pretreatment clearly suppressed post-CME myocardial apoptosis and improved cardiac function.The most likely mechanism for these effects is the blockade of the myocardial death receptor -mediated apoptosis pathway.

Irisin Attenuates Osteoarthritis by Inhibiting Apoptosis of Osteocytes Through Activating Erk Signaling Pathway

Osteoarthritis(OA)is an inflammatory disease involving the joints that is prevalent in the global aging population.The purpose of this study is to determine whether irisin can attenuate osteoarthritis(OA)progression in anterior cruciate ligament transection(ACLT)mice models and the mechanism of irisin therapy effect on OA by increase the resistance of apoptosis in MLO-Y4 cells induced by mechanical stretch in vitro.Methods For in vivo study,3-month-old male C57BL/6 J mice were randomized to three groups,sham-operated,anterior cruciate ligament transection(ACLT)-operated treated with vehicle,and ACLT-operated treated with irisin by intraperitoneal injection once a week.Cartilage erosion was observed by HE staining.Osteoarthritis Research Society International(OARSI)scores were evaluated according to the safranin O stai-ning.The microstructure of tibia cortical bone,trabecular bone,and subchondral bone was analyzed by micro-CT and the bone histomorphometry has been administrated including mineral apposition rate(MAR).Edu staining and cck-8 were used for the detection of the proliferation of MLO-Y4 cells.For mechanical stress,cells were seeded on the collagen-I coated chamber subjected with a peak biaxial stretch of 20%at 1 Hz for 16 hours to induce apoptosis.Flow cytometry was used for the detection of apoptosis and cell cycle.TUNNEL was used for staining the apoptotic cells and rt-PCR was applied for quantifying the expression of mRNA such as Bax,Bcl-2,SOST,c-myc,Opg.Western blot was utilized to confirm the mechanism of how irisin decrease the osteocyte apoptosis.Results In vivo,irisin can attenuate articular cartilage degeneration.Irisin maintains the proportion of hyaline cartilage and calcified cartilage and keep fewer cartilage erosions in ACLT-operated mice.For immunohistochemical(IHC)staining,irisin reduced the expression of caspase3,Bax and matrix metalloproteinase-13 in both cartilage and subchondral bone.Irisin-treated ACLT group shows higher Trabecular number(Tb.N)and bone volume fraction(BV/TV)compared to the vehicle-treated ACLT group.In vitro, irisin significantly increased the proliferation of MLO-Y4 cells detected by Edu and Ki67 staining,and irisin can protect the cells from both mechanical stretchinduced apoptosis detected by FITC-PI flow cytometry and maintain the cell activity by regulating the expression of Bax,Bcl-2,and c-myc.Transcriptome sequencing shows that irisin significantly activates the MAPK signaling pathway and we confirm the result by western blot:irisin effectively activates the Erk signaling pathway through phosphorylation and has a certain activation effect on p38 signaling pathway,no activation was observed for FAK signaling pathway.Conclusions Irisin can attenuate the progression of OA by decrease the apoptosis of osteocyte,which can improve the microarchitecture of subchondral bone.Erk pathway activation plays an important role in reducing the apoptosis of osteocyte.

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.

miR-485-5p调控MEK/ERK信号通路对肝癌细胞增殖、侵袭和凋亡的机制研究

目的探讨miR-485-5p调控MEK/ERK信号通路对肝癌细胞增殖、侵袭和凋亡的机制研究。方法选择2021年1月-2022年12月在我院行根治性肝癌切除术的肝癌患者50例,切除肝癌组织及癌旁组织后迅速液氮冷冻,RT-PCR检测组织及细胞中miR-485-5p相对表达量。将肝癌Hep3B细胞随机分为miR-NC组、miR-485-5p组和miR-485-5p+ML099组。CCK-8检测肝癌细胞增殖能力,Transwell法检测细胞侵袭能力,流式细胞仪检测细胞凋亡率,检测细胞中p-MEK、MEK、p-ERK、ERK蛋白表达(蛋白质印迹法)。结果与癌旁组织中miR-485-5p相对表达量(1.18±0.23)相比,肝癌组织(0.19±0.14)明显降低(P<0.01)。与人正常肝细胞株LO2 miR-485-5p相对表达量(1.26±0.23)相比,人肝癌细胞株Huh7(0.36±0.09)、Hep3B(0.17±0.06)和HepG2(0.31±0.07)明显降低(P<0.01)。与miR-NC组相比,miR-485-5p组Hep3B细胞中miR-485-5p相对表达量(1.25±0.18)和细胞凋亡率(18.62%±2.11%)明显升高,细胞活力(24 h:0.23±0.03,48 h:0.39±0.06,72 h:0.57±0.08)、细胞侵袭数目(71.06±8.92)和细胞中p-MEK/MEK比值(0.31±0.04)、p-ERK/ERK比值(0.42±0.05)明显降低(P<0.01);和miR-485-5p组相比,miR-485-5p+ML099组Hep3B细胞中miR-485-5p相对表达量(0.31±0.08)和细胞凋亡率(5.18%±0.64%)明显降低,细胞活力(24 h:0.24±0.04,48 h:0.61±0.08,72 h:0.98±0.10)、细胞侵袭数目(164.11±17.18)和细胞中p-MEK/MEK比值(0.69±0.08)、p-ERK/ERK比值(0.89±0.10)明显升高(P<0.01)。结论miR-485-5p在肝癌中呈低表达,过表达miR-485-5p可能通过抑制MEK/ERK信号通路抑制肝癌细胞增殖和侵袭,并诱导肝癌细胞凋亡。

连翘脂素调节Ras/Raf/MEK/ERK信号通路对结直肠癌细胞恶性生物学行为的影响

目的 探究连翘脂素(PG)对结直肠癌细胞增殖、迁移、侵袭、凋亡以及上皮间质转化的影响及机制。方法 培养HCT116结直肠癌细胞,采用10~200μmol/L的连翘脂素处理细胞,检测细胞存活率,筛选最佳实验浓度。将细胞分为对照组(Control组),连翘脂素低、中、高浓度组(PG-L组、PG-M组、PG-H组),连翘脂素高浓度+转染慢病毒阴性对照组(PG-H+NC组),连翘脂素高浓度+Ras慢病毒组(PG-H+Ras组)。平板克隆形成实验检测细胞增殖;划痕实验检测细胞迁移;Transwell小室法检测细胞侵袭;流式细胞术以及Hoechst33258染色法检测细胞凋亡;Western blot法检测上皮间质转化(EMT)标志蛋白E型钙黏蛋白(E-cadherin)、波形蛋白(Vimentin)以及信号通路相关蛋白p-Raf、p-MEK、p-ERK表达;建立荷瘤小鼠模型评价连翘脂素对结直肠癌肿瘤生长的影响。结果 10~200μmol/L的连翘脂素处理HCT116结直肠癌细胞,可以显著抑制细胞存活率,经计算IC50值为(140.4±2.147)μmol/L,选择10、50、100μmol/L连翘脂素进行后续实验;与Control组比较,PG-L组、PG-M组、PG-H组HCT116细胞克隆形成率、划痕愈合率、细胞侵袭个数以及Vimentin、p-Raf、p-MEK、p-ERK表达显著降低,细胞凋亡率以及E-cadherin表达显著升高,且呈浓度依赖性(P<0.05);与PG-H+NC组比较,PG-H+Ras组HCT116细胞克隆形成率、划痕愈合率、细胞侵袭个数以及Vimentin、p-Raf、p-MEK、p-ERK表达显著升高,细胞凋亡率以及E-cadherin表达显著降低(P<0.05);连翘脂素可以显著抑制结直肠癌移植瘤的生长。结论 连翘脂素可以抑制结直肠癌细胞增殖、迁移、侵袭、凋亡以及上皮间质转化,其作用机制可能与抑制Ras/Raf/MEK/ERK信号通路激活有关。

Effect of Guizhi Fuling Pill combined with GnRH analog on cell proliferation and invasion as well as MEK/ERK pathway in endometriosis lesions

Objective: To study the effect of Guizhi Fuling Pill combined with gonadotropin-releasing hormone analog (GnRH-a) on cell proliferation and invasion as well as MEK/ERK pathway in endometriosis lesions. Methods: Patients who were diagnosed with endometriosis in Bazhong Hospital of Traditional Chinese Medicine between November 2014 and March 2017 were selected as the research subjects and randomly divided into two groups, observation group received preoperative Guizhi Fuling Pill combined with GnRH analog therapy, and control group received preoperative GnRH analog monotherapy. After surgical resection, the endometriosis lesion was collected to determine the mRNA expression of proliferation and invasion-related genes as well as the protein expression of MEK/ERK pathway molecules. Results: Id-1, Sema3A, c-IAP1, OPN and uPA mRNA expression as well as p-MEK, p-EKR1/2, caspase-3 and MMP2 protein expression in endometriosis lesion of observation group were significantly lower than those of control group while Bak, Smac, PAI-1, TIMP1 and TIMP2 mRNA expression as well as caspase-3 protein expression were significantly higher than those of control group. Conclusion: Guizhi Fuling Pill combined with GnRH analog can inhibit the cell proliferation and invasion as well as the MEK/ERK pathway activation in endometriosis lesions.

GCS通过MEK/ERK通路调控白血病多药耐药细胞凋亡相关基因bcl-2的表达

目的:探讨葡萄糖神经酰胺合成酶(GCS)是否通过MEK/ERK信号通路调控凋亡相关基因bcl-2的表达,从而诱导人白血病K562/A02细胞多药耐药。方法:用小干扰RNA(siRNA)靶向干扰K562/A02细胞中GCS的表达,real-time PCR、Western blotting检测Bcl-2、磷酸化及总ERK水平;用MEK特异性化学抑制剂U0126抑制MEK/ERK信号通路的活化,real-time PCR与Western blotting技术分别检测Bcl-2 mRNA与蛋白水平;CCK-8试剂盒检测细胞存活情况。结果:与阴性对照组比较,GCS siRNA明显抑制K562/A02细胞GCS和Bcl-2的表达,并抑制MEK/ERK信号通路的活化;U0126使Bcl-2 mRNA及蛋白水平呈浓度依赖性下降,并使K562/A02细胞ADM敏感性增加。结论:GCS通过MEK/ERK信号通路调控K562/A02细胞株中凋亡相关基因bcl-2的表达,从而诱导白血病细胞多药耐药。

基于Raf/MEK/ERK信号通路探讨黄芪建中汤治疗大鼠脾胃虚寒型十二指肠溃疡的作用机制

目的探讨黄芪建中汤通过Raf/MEK/ERK信号通路治疗大鼠脾胃虚寒型十二指肠溃疡(DU)的作用机制。方法将60只SD大鼠随机分为正常对照组、模型组、埃索美拉唑组(4.17 mg·kg^(-1))以及黄芪建中汤高、低剂量组(18.54、9.27 g·kg^(-1))。采用“苦寒泻下+劳倦过度”法联合阿司匹林、无水乙醇构建脾胃虚寒型DU大鼠模型。灌胃给药,每天1次,连续4 d。观察大鼠十二指肠黏膜损伤情况并计算溃疡指数和治疗指数;采用HE染色法观察十二指肠黏膜组织病理形态学改变;采用酶联免疫吸附试验检测十二指肠组织中前列腺素E2(PGE2)、白细胞介素10(IL-10)、肿瘤坏死因子α(TNF-α)水平;免疫荧光法检测十二指肠黏膜磷酸化丝氨酸/苏氨酸蛋白激酶(p-Raf)、磷酸化有丝分裂原活化蛋白激酶激酶1/2(p-MEK1/2)、磷酸化细胞外信号调节激酶1(p-ERK1)蛋白表达。结果与正常对照组比较,模型组大鼠的十二指肠溃疡指数显著升高(P<0.01);小肠绒毛脱落,隐窝脓肿,小肠绒毛长度和隐窝深度均显著降低(P<0.01);肠黏膜PGE2、IL-10含量均明显降低(P<0.01),TNF-α含量显著增加(P<0.01);肠黏膜p-Raf、p-MEK1/2和p-ERK1蛋白表达量均明显增加(P<0.01)。与模型组比较,黄芪建中汤各剂量组的大鼠十二指肠溃疡指数均明显降低(P<0.01);肠黏膜损伤得到明显改善,黏膜形态趋于完整,小肠绒毛长度和隐窝深度均明显增加(P<0.01);肠黏膜PGE2和IL-10含量均明显提高(P<0.01),TNF-α含量显著降低(P<0.01);肠黏膜p-Raf、p-MEK1/2和p-ERK1蛋白表达均显著下调(P<0.01)。结论黄芪建中汤对脾胃虚寒型DU大鼠具有治疗作用,其机制可能与调控PGE2、TNF-α、IL-10等炎症介质水平,抑制Raf/MEK/ERK信号通路活化有关。

对药酸枣仁-合欢花对抑郁模型大鼠学习记忆能力及BDNF-MEK-ERK-CREB细胞信号转导通路的影响

目的:观察对药酸枣仁-合欢花对抑郁模型大鼠学习记忆能力及脑源性神经营养因子(BDNF)-丝裂原细胞外激酶(MEK)-细胞外信号调节蛋白激酶(ERK)-环磷腺苷反应元件结合蛋白(CREB)信号转导通路的影响,探讨对药酸枣仁(SZS)-合欢花(AJF)抗抑郁作用的机制。方法:将雄性SD大鼠按随机数字表法分为正常组(control)、模型组(CUMS)、对药酸枣仁-合欢花组(SZS+AJF)、盐酸文拉法辛组(Venlafaxine)、PD184161组(PD),采用孤养加慢性不可预知性温和应激(CUMS)复制抑郁症大鼠模型,并用Morris水迷宫实验评价各组大鼠不同时间学习记忆能力的改变。应用ELISA法测定血清BDNF水平,应用real time RT-PCR法测海马CREB、BDNF mRNA表达,应用Western Blot法测定海马ERK、p-ERK、p-RSK及p-CREB蛋白表达。结果:与Control组比较,CUMS组大鼠学习记忆能力下降(从第14 d开始有统计学意义,P <0. 05或P <0. 01),血清BDNF含量减少(P <0. 01),海马CREB、BDNF mRNA和ERK、p-ERK、p-RSK、p-CREB蛋白表达量减少(P <0. 05或P <0. 01)。与CUMS组比较,SZS+AJF组、Venlafaxine组、PD组大鼠学习记忆能力提高(从第14 d开始有统计学意义,P <0. 05或0. 01),血清BDNF含量增加(P <0. 05),海马CREB、BDNF mRNA和ERK、p-ERK、p-RSK、p-CREB蛋白表达量增加(P <0. 05或P <0. 01)。与SZS+AJF组比较,PD组大鼠学习记忆能力减少(第21 d有统计学意义,P <0. 05),血清BDNF含量减少(P <0. 05),海马CREB、BDNF mRNA和ERK、p-ERK、p-RSK、p-CREB蛋白表达降低(P <0. 05)。结论:对药酸枣仁-合欢花能够提高抑郁模型大鼠的学习记忆能力,具有抗抑郁效应,其作用机制可能与提高抑郁模型大鼠BDNF-MEK-ERK-CREB信号转导通路的关键因子表达有关。

异槲皮苷对HepG2细胞中Raf/MEK/ERK信号通路的干预作用

目的研究异槲皮苷对Hep G2细胞中Raf/MEK/ERK信号通路的干预作用。方法采用异槲皮苷(0、40、80、160、320μmol·L^(-1))作用于Hep G2细胞,MTT法检测异槲皮苷对Hep G2细胞增殖的影响;倒置显微镜下观察24、48 h后,细胞形态及生长情况;流式细胞术检测异槲皮苷(0、40、80、160μmol·L^(-1))作用Hep G2细胞48 h后细胞周期情况;荧光定量PCR及Western blot检测异槲皮苷作用Hep G2细胞后Ras、Raf、MEK、ERK mRNA及相关蛋白的表达。结果MTT检测发现异槲皮苷对Hep G2细胞生长有明显抑制作用,且与异槲皮苷的浓度及作用时间呈正相关;不同浓度的异槲皮苷作用Hep G2细胞24、48 h后,倒置显微镜下观察发现随着浓度的增高及作用时间的延长,细胞生存数量逐渐减少,且细胞形态发生明显变化;流式细胞术检测发现随着异槲皮苷浓度的增高,细胞被阻滞在G1期的数量逐渐增加;荧光定量PCR及Western blot结果均表明,与空白组相比,异槲皮苷(80μmol·L^(-1))作用Hep G2细胞后Ras、Raf、MEK、ERK mRNA及其相关蛋白的表达均明显降低(P<0.05),差异有统计学意义。结论异槲皮苷有诱导Hep G2细胞凋亡的作用,其作用机制可能与对Raf/MEK/ERK信号通路中相关因子的干预有关。

EdCC通过MEK-ERK信号通路减轻小鼠心肌缺血再灌注损伤

目的:研究子宫内膜干细胞(endometrial stem cells,EnSCs)来源细胞因子"鸡尾酒"(EnSC-derived cytokine cocktail,EdCC)对心肌缺血再灌注损伤的影响及MEK-ERK信号通路的作用。方法:建立小鼠心肌缺血再灌注损伤模型,用TTC/Evans blue染色评估心梗面积,TUNEL染色检测细胞凋亡,Western blot检测ERK1/2磷酸化水平和cleaved caspase-3表达。结果:EnSCs具有间充质干细胞特性,表达CD90,不表达CD34和CD45。EdCC的表皮生长因子(EGF)含量为(6 811±312)ng/g蛋白。经尾静脉注射EdCC可显著升高心肌ERK1/2磷酸化水平,明显降低梗死面积,减少梗死周边区凋亡细胞数目,抑制capase-3活化。MEK1特异性阻断剂PD98059(5 mg/kg)抑制EdCC介导的ERK1/2磷酸化,并抵消上述心肌保护效应。EGF受体特异性阻断剂AG-1487(6 mg/kg)只能部分抵消EdCC的心肌保护作用,而单纯注射EGF不能缩小梗死面积。结论:EdCC通过激活MEK1-ERK1/2信号通路减轻心肌缺血再灌注损伤,EGF受体是该通路重要组成部分。该结果对目前成体干细胞移植治疗模式——从细胞转移到细胞因子,具有重要的理论意义。

IKKε通过调控异常的MAPK/MEK/ERK信号转导通路参与急性主动脉夹层形成的机制研究

目的分析MAPK/MEK/ERK信号转导通路与急性主动脉夹层形成的关系及IKKε的调控作用,为临床相关治疗和新药研发提供参考。方法清洁级C57BL/6小鼠随机分为5组:对照组、模型组、IKKε-IN-1低剂量、中剂量和高剂量干预组。除对照组外,其余各组小鼠给予2 500 ng/(kg·min)血管紧张素Ⅱ(对照组给予生理盐水)14 d。自第7天起IKKε-IN-1低剂量、中剂量和高剂量干预组小鼠分别给予IKKε-IN-1治疗(1 mg/kg、5 mg/kg和25 mg/kg)。采用老龄小鼠埋泵缓释血管紧张素Ⅱ建立急性主动脉夹层动物模型,并采用IKKε特异性拮抗剂IKKε-IN-1进行干预,分析各组小鼠血浆MAPK/MEK/ERK信号转导通路相关蛋白表达。结果清洁级C57BL/6小鼠皮下植入缓释泵输注血管紧张素Ⅱ7 d后模型组小鼠收缩压为153±11.4 mm Hg(对照组为105±10.4 mm Hg),14 d后收缩压变为176±12.6 mm Hg,而IKKε-IN-1低剂量、中剂量和高剂量干预组小鼠的收缩压明显低于模型组(P<0.05),且呈剂量依赖性(P<0.05);与对照组相比,急性主动脉夹层小鼠Ras、Raf、MEK、ERK1/2、基质金属蛋白酶2(MMP2)及基质金属蛋白酶6(MMP6)蛋白表达明显增强而金属蛋白酶组织抑制因子1(TIMP1)和金属蛋白酶组织抑制因子2(TIMP2)的表达明显减弱(P<0.05),而IKKε-IN-1低剂量、中剂量和高剂量干预组上述蛋白的表达明显恢复(P<0.05),且呈剂量依赖性(P<0.05)。结论激活的MAPK/MEK/ERK信号转导通路及基质金属蛋白酶参与了急性主动脉夹层形成,且此过程与IKKε的调控密切相关。

大鼠增殖抑制基因通过Ras-Raf-MEK-ERK信号通路抑制C6胶质瘤细胞增殖

目的探讨Ras-Raf-MEK-ERK通路在大鼠增殖抑制基因(r HSG)抑制C6大鼠胶质瘤细胞增殖中的作用。方法用r HSG过表达腺病毒载体(Adv-r HSG-GFP)转染C6细胞后,流式细胞仪分析腺病毒转染效率;Western blot检测r HSG蛋白表达变化;流式细胞仪分析细胞周期;qRT-PCR检测H-ras、N-ras、K-ras、Erk1、Erk2基因mRNA表达变化;Western blot检测H-ras、N-ras、K-ras、p-Erk1/2、Erk1/2、p-Rb、Rb蛋白表达变化。结果腺病毒载体能高效的转染C6细胞并表达GFP蛋白,Adv-r HSG-GFP组r HSG蛋白表达显著高于未转染组(PBS)和AdvGFP组,C6细胞被阻滞于G0/G1期(P<0.01);经IGF-1刺激后,Adv-r HSG-GFP组细胞H-ras、N-ras、K-ras、Erk1、Erk2基因的mRNA和蛋白表达水平与PBS组和Adv-GFP组无明显差异(P>0.05);Adv-r HSG-GFP组细胞过表达r HSG能显著抑制IGF-1诱导的Erk1/2的活化,p-Erk1/2蛋白表达量显著低于其余两组(P<0.01);同时其p-Rb蛋白的表达量显著低于其余两组(P<0.01),而Rb蛋白表达量3组无明显差异(P>0.05)。结论 r HSG可能通过抑制Ras-Raf-MEK-ERK信号通路的激活抗C6恶性胶质瘤细胞增殖。

绿原酸对心肌细胞炎症反应和MEK/ERK信号通路的影响

目的:探讨绿原酸对心肌细胞炎症反应和MEK/ERK信号通路的影响。方法:常规培养心肌细胞,利用脂多糖(lipopolysaccharide,LPS)诱导细胞炎症模型,将细胞分为正常对照组、LPS诱导组、LPS+50μg/mL绿原酸组、LPS+100μg/mL绿原酸组、LPS+200μg/mL绿原酸组;采用CCK8试验分析绿原酸对心肌细胞相对存活率的影响,流式细胞术检测绿原酸对心肌细胞凋亡的影响,ELISA法分析绿原酸对心肌细胞炎症反应的影响,免疫印迹法探讨绿原酸对心肌细胞MEK/ERK信号通路活化的影响。结果:LPS诱导组心肌细胞凋亡率为(52.3±4.2)%,高于正常对照组的(4.6±0.7)%;LPS诱导组炎症因子白细胞介素6(IL-6)为(1702±287)pg/mL,高于正常对照组的(529±102)pg/mL;LPS诱导组肿瘤坏死因子α(TNF-α)为(198±24)pg/mL,高于正常对照组的(81±13)pg/mL;LPS诱导组较正常对照组MEK及p-ERK蛋白表达水平显著上调(P<0.05)。与LPS诱导组相比,绿原酸可以提高细胞的存活率、抑制其凋亡、降低炎症因子IL-6和TNF-α的释放、抑制MEK/p-ERK蛋白的表达,相对于LPS诱导组差异均有统计学意义(P<0.05)。结论:绿原酸可降低LPS诱导的心肌细胞炎症反应,其机制可能与抑制MEK/ERK信号通路活化有关。