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@#Ets transcription factor ELK 1,a member of the ternary complex factor(TCF) subfamily in the Ets family,is directly downstream signal of MAPK/ERK pathway and is activated by phosphorylation to execute the function of ERK signal.ELK1,which is highly expressed and phosphorylated in stem cells and tumor cells,plays a role in promoting proliferation,inhibiting apoptosis and differentiation in stem cells.In tumor cells,ELK1 has shown to promote proliferation,migration,and inhibit apoptosis.In neural cells,ELK1 is involved in long-term memory,learning,addiction and other functions.In this paper,the research progress on the main structure and basic biological characteristics of ELK1,the function and mechanism of ELK 1 in tumor cells,stem cells and nerve cells are reviewed in order to provide new ideas for the follow-up research.
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OBJECTIVE@#To investigate the effects of SINC, a secreted protein of Chlamydia psittaci, on autophagy of host cells and the role of MAPK/ERK signaling pathway in mediating SINC-induced autophagy.@*METHODS@#RAW 264.7 cells treated with recombinant SINC were examined for changes in expression levels of LC3-II, Beclin-1, phosphorylated and total ERK1/2 using Western blotting. The expression level of LC3 in the treated cells was detected using immunofluorescence analysis, and the formation of autophagosomes and autolysosomes was observed with transmission electron microscopy (TEM). The effect of pretreatment with U0126 (a specific ERK inhibitor) on the expression levels of LC3-II and Beclin-1 in RAW 264.7 cells exposed to different concentrations of SINC was examined using Western blotting, and LC3 puncta in the cells was detected with immunofluorescence analysis.@*RESULTS@#The expression levels of LC3-II and Beclin-1 were the highest in RAW 264.7 cells treated with 2 μg/mL SINC for 12h. Immunofluorescence analysis showed exposure to SINC significantly increased the number of cells containing LC3 puncta, where the presence of autophagosomes and autolysosomes was detected. Exposure to 2 μg/mL SINC for 15 min resulted in the most significant increase of the ratios of p-ERK1/2/ERK1/2 in RAW 264.7 cells. Pretreatment of the cells with U0126 prior to SINC exposure significantly decreased the ratio of p-ERK1/2/ERK1/2, lowered the expression levels of LC3-II and Beclin-1, and decreased LC3 aggregation in the cells.@*CONCLUSIONS@#SINC exposure can induce autophagy in RAW 264.7 cells by activating the MAPK/ERK signaling pathway.
Subject(s)
MAP Kinase Signaling System , Chlamydophila psittaci , Beclin-1 , Signal Transduction , AutophagyABSTRACT
Objective:To explore the role of transgelin(TAGLN) in the occurrence and development of papillary thyroid carcinoma (PTC) and its possible signal pathway.Methods:One hundred cases of PTC tissues and corresponding paracancerous normal thyroid tissues were collected. Realtime quantitative PCR (RT-qPCR), Western blotting, and immunohistochemistry were used to analyze the expression of TAGLN in PTC tissues and corresponding paracancerous normal thyroid tissues. PTC cells were transfected with plasmid and shRNA lentivirus vector respectively to up-regulate or down-regulate the expression of TAGLN in order to detect the effects of them on the proliferation, invasion, and migration by cell proliferation assay(cell counting kit-8, CCK-8)and cell invasion and migration assays (Transwell). The effects of TAGLN on mitogen-activated protein kinase (MAPK)/extracellular-signal regulating kinase (ERK) signal pathway was detected with Western blotting.Results:RT-qPCR showed that there was no difference in the expression of TAGLN mRNA between PTC and corresponding paracancerous normal thyroid tissues ( P>0.05); Western blotting demonstrated that the expression of TAGLN protein in PTC tissues was significantly lower than that in corresponding paracancerous normal thyroid tissues ( P<0.01). Immunohistochemical results revealed that the expression of TAGLN in PTC tissues was significantly lower than that in corresponding paracancerous normal thyroid tissues. Overexpression of TAGLN inhibited the proliferation, invasion, and migration of PTC cells ( P<0.01), but knockdown of TAGLN promoted the proliferation, invasion, and migration of PTC cells ( P<0.01). Overexpression of TAGLN decreased the expression of phosphorylated ERK ( P<0.05), whereas silencing TAGLN increased phosphorylated ERK level in PTC cells( P<0.01). Conclusion:The expression of TAGLN in PTC is significantly decreased. It is related to the occurrence and development of PTC, and its mechanism may be related to MAPK/ERK signal pathway.
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BACKGROUND: C-terminus of the amelogenin peptide (AMG-CP) is a small molecular endogenous peptide that is highly shown that AMG-CP can regulate the proliferation and differentiation of cementoblasts, bone marrow mesenchymal stem cells and periodontal ligament fibroblasts, but the biological function of AMG-CP on ameloblasts has not been elucidated. O conserved among species. It is involved in important physiological processes during tooth development. Some studies have BJECTIVE: To investigate the effects of different concentrations of AMG-CP on the proliferation of ALC ameloblasts and its underlying mechanisms. METHODS: AMG-CP was successfully synthesized and determinated by liquid chromatography and mass spectrometry. The effects of AMG-CP at 0, 0.5, 1, 2 mg/L on the proliferation of ALC ameloblasts were observed by xCELLigence RTCA cell analysis system in real time. The effect of AMG-CP at 0, 1, 2 mg/L on cell cycle of ALC was detected by flow cytometry. Real-time PCR was used to detect the expression of cyclin D1, CDK4, MCM2, MCM5 mRNA in ALC cells treated with AMG-CP at 0, 1, 2 mg/L. Western blot was carried out to evaluate the effect of AGM-CP at 0, 1 mg/L on MAPK-ERK1/2 pathway by detecting the expression of phosphorylated ERK1/2 and total ERK1/2 in ALC cells. Pathway blockade assay was performed by using ERK1/2 blocker U0126 to pretreat ALC cells. Then cell proliferation ability as well as phosphorylated ERK1/2 expression was analyzed by xCELLigence RTCA cell analysis system and western blot. RESULTS AND CONCLUSION: Compared with the control group, AMG-CP promoted the proliferation of ALC cells, and decreased the population doubling time in a dose-depending manner. Flow cytometry detected the acceleration of cell cycle after treatment with AMG-CP. The results of Real-time PCR showed that AMG-CP upregulated cell cycle-related genes (cyclin D1, CDK4, MCM2, MCM5) expression. Western blot results showed that AMG-CP could upregulate the expression of phosphorylated ERK1/2 and activate MAPK-ERK1/2 signaling pathway in ALC cells. After U0126 was used to inhibit the MAPK-ERK1/2 pathway, the ability of AMG-CP promoting ALC proliferation was inhibited. These results suggest that AMG-CP has a potential to activate MAPK-ERK1/2 pathway, accelerate the process of cell cycle, and then promote the proliferation of ALC cells, all of which indicate that AMG-CP has the potential to promote the proliferation of ameloblasts.
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Aim: To investigate the effect of melatonin on neuroprotection in cerebellums of rats with Alzheimer' s disease via MAPK/ERK signaling pathway. Methods: Thirty-two male Sprague-Dawley rats were randomly divided into four groups: control group, Aβ1-42 lateral ventricle injection group (AD), and melatonin intraperitoneal injection group (MT), and Aβ1-42 lateral ventricle injection combined with melatonin intraperitoneal injection group (AD + MT). The pathological changes of rat cerebellar cortex were detected by HE staining; the expression of NeuN (neuronal marker), Calbindin(Purkinje cell marker) and p-ERK protein in each group was detected by immunofluorescence; the expression of ERK and p-ERK in each group was determined by Western blot. Results: The HE staining showed that the expression of neurons decreased, followed with the disordered arrangement and morphological alteration of cells in AD. Melatonin could significantly alleviate the pathological damage in cerebellum. Immunofluorescence results showed that compared with AD group, the expression of NeuN (neuronal marker) increased, the number of Purkinje cells marked by Calbindin significantly was up-regulated(P < 0. 01), and the expression of p-ERK was down-regulated in AD + MT group. Western blot showed that the expression of p-ERK was down-regulated by melatonin. Conclusions: Melatonin may exert the neuroprotective effect and relieve the pathological changes by inhibiting the activation of MAPK/ERK signaling pathway.
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;Aim To study the effect of Yiqi Jiedu formula extract on the apoptosis of nasopharyngeal carcinoma cells, and explore the mechanism of its induction of apoptosis from MAPK/ERK signaling pathway. Methods The effect of Yiqi Jiedu Formula extract on the proliferation of CNE1 and CNE2 cells was detected by CCK-8. The apoptosis of CNE1 and CNE2 cells was detected by Hoechst 33342 staining, JC-10 staining and fluorescence double dye flow cytometer staining. The protein expression of CNE1 and CNE2 cells was detected by Western blot. Results Yiqi Jiedu formula extract inhibited the proliferation (P < 0. 05) and induced apoptosis (P <0. 05) of CNE1 and CNE2 cells. After 48 h of drug treatment, the expression of Survivin, XIAP and Bcl-2 decreased, Bax increased, and p-c-Raf, p-MEK and p-ERKl/2 of MAPK/ERK signaling pathway significantly decreased (P < 0. 05). On this basis, after adding activator of MAPK/ERK signaling pathway ISO, the expression of p-c-Raf, p-MEK and p-ERKl/2,Survival, XIAP and Bcl-2 increased, while the expression of Bax decreased compared with the extract of YQ group. Drug-induced apoptosis effects were also reduced. Conclusions Yiqi Jiedu formula extract can induce the apoptosis of nasopharyngeal carcinoma cells, which inhibits the expression of key proteins p-c-Raf, p-MEK and p-ERKl/2 in MAPK/ERK signaling pathway, and then down-regulates the expression of Survivin, XIAP, Bcl-2 and up-regulates the expression of Bax.
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This study was designed to explore proteins differentially expressed in HER2 positive gastric cancer N87 cells and N87/R cells with an acquired resistance to herceptin based on label-free quantitative proteomics. The extracted proteins were reduced and alkylated, then digested using filter aided sample preparation (FASP); peptides were separated via small manual reversed phase column, analyzed by LC-MS/MS, and identified with protein database 2.1 search engine. Proteins were quantified by intensity based quantification (IBQ) to search for differential proteins by comparison with relatively quantified proteins. The enrichment and network construction in gene ontology (GO) terms, genes-disease and Wikipathway of differential proteins were established through Web Gestalt. A total of 8 509 proteins were detected, among them, 7 163 proteins were further analyzed by bioinformatics, of which 110 proteins were up-regulated and 70 were down-regulated in N87/R cells. The differential proteins showed a significant difference in cellular component, biological process and molecular function in GO terms, respectively. Genes-disease network analysis indicated the association of these differential proteins with neoplasm metastasis, neoplasm invasiveness and inflammation, etc. Wikipathway enrichment analysis revealed the relevance of several signaling pathways to herceptin resistance, which included IL-2, MAPK/ERK, mTOR, aurora A, Ret, NF-κB, immune-regulatory and metabolic pathway. Western blot showed a significant increase of ERK1/2 activities in N87/R cells compared with N87 cells. Correspondingly, SCH772984, a MAPK/ERK inhibitor, preferentially reduced the viability of N87/R cells. Taken together, our data suggested that the MAPK/ERK signaling pathway is one of the key pathways that mediate herceptin resistance. This study provides the basic information for exploring the mechanisms of acquired resistance to herceptin in gastric cancer cells.
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AIM:To observe the effects of panaxadiol saponins(PDS)on up-regulation of MAPK/ERK signal pathway in bone marrow cells and increase in regulatory T(Treg)cells in spleen tissue of aplastic anemia(AA)mice,and to explore the mechanisms.METHODS:For preparation of immune-mediated AA model,BALB/c mice were exposed to sublethal dose(5.0 Gy)of [60Co]-γradiation, followed by transplantation of lymphocytes from DBA /2 donor mice. BALB/c mice(n=60)were randomly divided into 6 groups,including normal mouse group,AA model group,PDS treat-ment groups at low,medium and high doses,and cyclosporine group as positive control.PDS and cyclosporine were given by gavage for 14 d.The peripheral blood cell counts and bone marrow pathological examination were tested.The protein levels of MEK1/2,p-MEK1/2,ERK1/2 and p-ERK1/2 in the bone marrow cells were analyzed by Western blot and im-munohistochemistry experiment.Flow cytometry was used to detect the proportion of Treg cells in spleen tissue of each group.RESULTS:The peripheral blood cell counts were significantly decreased in AA mouse group as compared with nor -mal mouse group(P<0.05).The bone marrow sections showed markedly inhibition status of hematopoiesis and the de -crease in cellularity.In response to PDS treatment,the peripheral blood cell counts and Treg cells in the spleen tissues of AA mouse treated with PDS were significantly increased in a dose-dependent manner(P<0.05).Treatment with PDS at medium and high doses up-regulated the protein levels of MEK1/2,p-MEK1/2,ERK1/2 and p-ERK1/2 in the bone mar-row of AA mice(P<0.05).CONCLUSION:PDS is effective to enhance recovery of hematopoietic function in AA mice. This effect may be related to up-regulating multiple protein kinases of MAPK/ERK signal pathway in the bone marrow cells of AA mice.In addition,PDS has an impact on immune function of AA mice.
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AIM: To investigate the effects of marrow stromal cell line HS-5 on human lung adenocarcinoma A549 cells in the tumor microenvironment.METHODS:The effects of HS-5 cell-conditioned medium(HS-5-CM)on the viability and migration ability of A549 cells were detected by MTT assay and wound-healing assay.After treatment with HS-5-CM,the expression of CX3C chemokine receptor 1(CX3CR1)at mRNA level in the A549 cells was examined by qPCR. The protein levels of p-ERK and ERK in the A549 cells treated with MAPK/ERK pathway inhibitor U0126 were observed by Western blot,the migration ability of the A549 cells was measured by wound-healing assay,and the protein expression of CX3CR1 was determined by Western blot.RESULTS: HS-5-CM promoted the viability and migration ability of the A549 cells(P<0.01).The expression of CX3CR1 at mRNA level in the A549 cells was increased after treatment with HS-5-CM.MAPK/ERK inhibitor U0126 inhibited the activation of MAPK/ERK signaling pathway(P<0.01), and re-duced the migration ability(P<0.01)and the expression of CX3CR1(P<0.05)in the A549 cells.CONCLUSION:HS-5-CM significantly promotes the A549 cell viability and migration ability.Activation of MAPK/ERK signaling pathway and the expression of CX3CR1 may play a important role in this process.
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To study the effect of aqueous extracts of Yiqi Jiedu formula (YQ) on the proliferation of CNE2 cells in human nasopharyngeal carcinoma, and investigate its mechanism to provide a new theoretical basis for the clinical application of YQ. CNE2 cells were treated with different concentrations (0.125, 0.25, 0.5, 0.25 g·L⁻¹) of YQ, positive control medicine (cisplatin 4.0 mg·L⁻¹), inhibitor PD98059 (50 μmol·L⁻¹), activator isoproterenol hydrochloride (20 μmol·L⁻¹), activator isoproterenol hydrochloride (ISO)+YQ 0.5 g·L⁻¹. Then cell labeling by using real-time analyzer (RTCA) and CCK 8 method were used to detect cell proliferation activity, and the half inhibitory concentration (IC₅₀) was calculated. The cell cycle distribution was detected by fluorescence double dye flow cytometry PI staining, and Western blot method was used to detect the expression levels of related protein and MAPK/ERK signaling pathway. The results of RTCA and CCK-8 test showed that as compared with the control group, YQ group could effectively inhibit the proliferation of CNE2 cells (<0.01), with a dose and time dependence, and 48 h IC₅₀ value was 0.5 g·L⁻¹. The results of cell cycle showed that after 48 h of water extract treatment, the cell cycle was significantly changed, the proportion of G₀/G₁ was reduced, the ratio of G₂/M increased, and the cell cycle was in G₂/M period (<0.01). Western blot results showed that after 48 h treatment with different concentrations of aqueous extract, cell cycle-related proteins cyclinD1, cyclinD3 and CDK2 expression levels were down-regulated; MAPK/ERK signaling pathway related protein p-c-Raf, p-MEK, p-ERK1/2 expression level significantly lower as compared with the control group (<0.05). After adding activator and inhibitor in MAPK/ERK signaling pathway on this basis, the results showed that after adding activator ISO, cell proliferation was significantly higher than that in the Control group; the cycle related proteins cyclinD1, cyclinD3, and CDK2 expression levels were increased; at the same time, key protein p-c-Raf, p-MEK, p-ERK1/2 expression levels in the signal pathways were relatively increased. While after the addition of inhibitor PD98059, the cell proliferation was significantly lower than that in the Control group, and the expression level of corresponding protein was decreased, which was significantly different from the Control group (<0.05). So YQ could block cell cycle and inhibit the proliferation of CNE2 cells mainly by reducing the expression of MAPK/ERK signaling pathway key protein p-c-Raf, p-MEK and p-ERK1/2.
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Objective By constructing mortalin stably expressing ovarian cancer cell lines in A 2780 and A2780/cis, we demonstrate the role of mortalin in the ovarian cancer cell growth .Methods CCK-8 assay was used to measure cell viability in the overexpression mortalin group compared with the control group .The flow cytometry analysis was used to understand the effect of upregulated mortalin on the ovarian cancer cell cycle .Western blotting was used to determine the expression and phosphorylation level of MAPK /ERK and JNK/SAPK signal pathways .Results The results showed that increased expression of mortalin could accelerate ovarian cancer cell proliferation and promote G 1 transition, leading to a faster restoration of normal distribution of cell cycle .We found that mortalin overexpression significantly activated p-Raf and p-ERK1/2, but not p-JNK.Conclusion The results demonstrate that mortalin effect on the ovarian cancer cell proliferation contributes to active the MAPK-ERK signaling pathway .