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Objective:To analyze the mutation characteristics of Kirsten rat sarcoma virus oncogene homology (KRAS) gene in patients with appendiceal adenocarcinoma and its relationship with the activity of Ras Raf Mitogen activated protein kinase/extracellular regulated protein kinase (MAPK/ERK) signaling pathway.Methods:A total of 41 patients with appendiceal adenocarcinoma who were treated in the Lishui Central Hospital from January 2014 to January 2020 were selected as the observation group, and 50 patients with Appendicitis who were operated at the same time were randomly selected as the control group. Clinical and follow-up data were collected, and the mutation of the KRAS gene in the patient′s tissue was measured using the snapshot method. The expression of key proteins in the MAPK/ERK signaling pathway in cancer tissue was measured using Western blotting (WB) assay. We compared the clinical characteristics and prognosis of patients with KRAS mutation and non KRAS mutation appendiceal adenocarcinoma.Results:The KRAS gene mutation rate in the observation group was higher than that in the control group (41.5% vs 10.0%), and the expression levels of p-ARAF/ARAF, p-MEK1/MEK1, and p-ERK1/ERK1 proteins were also higher than those in the control group. The differences between the groups were statistically significant (all P<0.05). The protein expression levels of p-ARAF/ARAF, p-MEK1/MEK1, p-ERK1/ERK1 in KRAS mutation patients in the observation group were significantly higher than those in non KRAS mutation patients. The proportion of stage IV, positive rates of carcinoembryonic antigen (CEA), carbohydrate antigen (CA)199 and CA125 in KRAS mutation patients were higher than those in non KRAS mutation patients, and the survival time and progression free survival time were shorter than those in non KRAS mutation patients, with statistical significance (all P<0.05). Conclusions:The mutation rate of KRAS in appendix adenocarcinoma is high, and the activation of MAPK/ERK signaling pathway caused by KRAS mutation may play a role in the pathogenesis of appendix adenocarcinoma, which has the value of in-depth research.
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Colorectal cancer (CRC) is a type of malignant tumor that seriously threatens human health and life, and its treatment has always been a difficulty and hotspot in research. Herein, this study for the first time reports that antipsychotic aripiprazole (Ari) against the proliferation of CRC cells both in vitro and in vivo, but with less damage in normal colon cells. Mechanistically, the results showed that 5-hydroxytryptamine 2B receptor (HTR2B) and its coupling protein G protein subunit alpha q (Gαq) were highly distributed in CRC cells. Ari had a strong affinity with HTR2B and inhibited HTR2B downstream signaling. Blockade of HTR2B signaling suppressed the growth of CRC cells, but HTR2B was not found to have independent anticancer activity. Interestingly, the binding of Gαq to HTR2B was decreased after Ari treatment. Knockdown of Gαq not only restricted CRC cell growth, but also directly affected the anti-CRC efficacy of Ari. Moreover, an interaction between Ari and Gαq was found in that the mutation at amino acid 190 of Gαq reduced the efficacy of Ari. Thus, these results confirm that Gαq coupled to HTR2B was a potential target of Ari in mediating CRC proliferation. Collectively, this study provides a novel effective strategy for CRC therapy and favorable evidence for promoting Ari as an anticancer agent.
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Objective: To investigate the effect and possible mechanism of Y-box-binding protein 1 (YB-1) on sorafenib resistance in hepatoma cells. Methods: Lentiviral vectors with YB-1 overexpression and knockdown were constructed, respectively, to stimulate human hepatoma cell lines (HepG2 and Huh7) alone or in combination with sorafenib.The overexpression part of the experiment was divided into four groups: overexpression control group (Lv-NC), YB-1 overexpression group (Lv-YB-1), overexpression control combined with sorafenib resistance group (Lv-NC+sorafenib), YB-1 overexpression combined with sorafenib resistance group (Lv-YB-1 + sorafenib). The knockdown part of the experiment was also divided into four groups: knockdown control group (Lv-shNC), YB-1 knockdown group (Lv-shYB-1), knockdown control combined with sorafenib resistance group (Lv-shNC + sorafenib), YB-1 knockdown combined with sorafenib resistance group (Lv-shYB-1 + sorafenib). The occurrence of cell apoptosis was detected by TUNEL. The protein expression levels of phosphorylated (p)-ERK and ERK, key proteins in the extracellular regulatory protein kinase (ERK) signaling pathway, were detected by Western blot and quantified by ImageJ software. Subcutaneous tumorigenesis experiments were performed in nude mice. The effect of YB-1 on the efficacy of sorafenib was verified in vivo. The comparison between the two sets of data was carried out by an independent sample t-test. One-way ANOVA was used for comparisons between the three groups of data above. Results: Sorafenib had accelerated the occurrence of apoptosis in hepatoma cells, while YB-1 overexpression had inhibited cell apoptosis, and at the same time also inhibited the apoptosis-accelerating impact of sorafenib. On the contrary, YB-1 knockdown accelerated cell apoptosis and amplified the induction effect of sorafenib on apoptosis. Furthermore, sorafenib resistance had down-regulated p-ERK levels (HepG2: Lv-NC 0.685 ± 0.143, Lv-NC + sorafenib 0.315 ± 0.168, P < 0.05; Huh7: Lv-NC 0.576 ± 0.078, Lv-NC + sorafenib 0.150 ± 0.131, P < 0.01), whereas YB-1 overexpression had inhibited sorafenib resistance p-ERK reduction (HepG2: Lv-NC + sorafenib 0.315 ± 0.168, Lv-YB-1 + sorafenib 0.688 ± 0.042, P < 0.05; Huh7: Lv-NC + sorafenib 0.150 ± 0.131, Lv-YB-1 + sorafenib 0.553 ± 0.041, P < 0.05). YB-1 knockdown further increased sorafenib-induced p-ERK downregulation (HepG2: Lv-shNC + sorafenib 0.911 ± 0.252, Lv-shYB-1 + sorafenib 0.500 ± 0.201, P < 0.05; Huh7: Lv-shNC + sorafenib 0.577 ± 0.082, Lv-shYB-1 + sorafenib 0.350 ± 0.143, P < 0.05), which was further verified in naked mice (Lv-shNC + sorafenib 0.812 ± 0.279, Lv-shYB-1 + sorafenib 0.352 ± 0.109, P < 0.05). Conclusion: YB-1 mediates the occurrence of sorafenib resistance via the ERK signaling pathway in hepatoma cells.
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Humans , Animals , Mice , Cell Line, Tumor , Sorafenib/pharmacology , Drug Resistance, Neoplasm , Y-Box-Binding Protein 1/metabolism , Carcinoma, Hepatocellular/metabolism , MAP Kinase Signaling System , Mice, NudeABSTRACT
Objective:To analyze the effect of Croton leaf on ERK1/2 pathway in hippocampal of rats with cerebral ischemia-reperfusion.Methods:A total of 216 SD male rats were divided into sham operation group, model group, nimodipine group, low-dose, medium-dose and high-dose groups of croton leaf according to random nubmer table method, with 36 rats in each group. The MACO model of rats was prepared by the method of wire embolization. The high, medium and low dose groups were intragastrated with the water decoction 0.06 g/ml, 0.12 g/ml and 0.18 g/ml of Croton leaf; nimodipine group was intragastrated with nimodipine suspension 1.08 g/L; sham operation group and model group were intragastrated with equal volume of normal saline. Garcia JH score was used to conduct neurological function score, and HE staining was used to observe the morphology of hippocampal neurons after 7 days of continuous administration. Apoptosis of hippocampal CA3/DG region was detected by TUNEL assay. Western Blot was used to detect the expression of ERK1/2 and p-ERK1/2 proteins.Results:Compared with the model group at simultaneous point, the neurological function scores of low-dose, medium-dose and high-dose groups of Croton leaf increased ( P<0.01), the number of apoptotic cells decreased ( P<0.01), the expression of p-ERK1/2 / ERK1/2 [1 d: (0.22±0.03, 0.34±0.02, 0.46±0.01 vs. 0.19±0.02); 3 d: (0.38±0.02, 0.50±0.02, 0.68±0.02 vs. 0.27±0.02); 7 d: (0.29±0.03, 0.43±0.02, 0.59±0.02 vs. 0.21±0.03)] in hippocampus of the low-dose, medium-dose and high-dose groups of Croton leaf significantly increased ( P<0.01). Conclusion:Croton leaf could regulate the expression of ERK1/2 pathway protein upward, effectively improve the neural function and resist the apoptosis of hippocampal CA3/DG area of rats with cerebral ischemia-reperfusion injury.
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Objective:To investigate the mechanism of levosimendan on acute kidney injury after cardiopulmonary resuscitation (CPR) in rats.Methods:Twenty-five healthy adult male SD rats were randomly divided into three groups: control group ( n=5), levosimendan group ( n=10) and experimental group ( n=10). A cardiac arrest-cardiopulmonary resuscitation model was established using smothering method in the experimental group and levosimendan group. The levosimendan group was treated with levosimandan during and after resuscitation, while the experimental group was given equivalent volume of saline solution during and after resuscitation, and the control group was only given equivalent volume of saline without performance of CPR. The rats in the three groups were sacrificed at 6 h after resuscitation. The serum and kidney tissue samples were collected. Serum biochemical indicators [serum creatinine (Scr), blood urea nitrogen (Bun), interleukin-1β (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α)] were measured. HE staining and Paller score were used to identify the degree of kidney damage. Apoptosis was estimated by TUNEL staining. Western blot was used to detect the expression levels of phosphorylation of extracellular regulated protein kinases (p-ERK). One-way analysis of variance was used to compare the mean values of normally distributed measurement data between groups. Comparisons between groups were performed using the least significant difference t-test. Results:Scr (85.02±1.31) μmol/L, Bun (7.36±0.13) mmol/L, Paller score (7.3±0.2), IL-1β (302.20±17.35) pg/mL, IL-6 (564.60±23.24) pg/mL and TNF-α (1346±83.73) pg/mL in the experimental group were significantly higher than those of the control group [(15.94±0.96) μmol/L, (2.95±0.18) mmol/L, (0.7±0.2), (7.27±0.44) pg/mL, (51.30±2.87) pg/mL, and (10.39±0.52) pg/mL] (all P<0.01). Compared with the experimental group, Scr (63.88±2.01) μmol/L, Bun (5.45±0.47) mmol/L, paller score (4.8±0.2), IL-1β (78.61±3.66) pg/mL, IL-6 (297.90±13.64) pg/mL and TNF-α (276.2±20.18) pg/mL were significantly decreased in the levosimendan group (all P<0.01). TUNEL staining showed that levosimendan could improve the apoptosis of renal cells ( P<0.01). The expression of p-ERK protein in the levosimendan group was significantly higher than that in the experimental group ( P<0.01). Conclusions:Lovosimendan could attenuate acute kidney injury following cardiac arrest and cardiopulmonary resuscitation via suppression apoptosis. The mechanism of levosimendan protective effect might be associated with activation of ERK signaling pathway.
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【Objective】 To study the role of dual-specificity phosphatase 15 （DUSP15） in mouse nucleus accumbens （NAc） in morphine sensitization. 【Methods】 The distance was recorded by open field test （OFT）， and morphine sensitization behavior was observed by acute morphine administration. The protein expressions of extracellular regulated protein kinases （ERK）， p-ERK and DUSP15 were tested using Western blotting. DUSP15-overexpressed virus （AAV-DUSP15） was injected into mouse NAc by brain stereotactic injection. Immunofluorescence staining confirmed viral expression. Western blotting was used to detect the effect of AAV-DUSP15 on the expressions of DUSP15， ERK and P-ERK. OFT was used to observe morphine sensitization behavior. 【Results】 The sensitization behavior was induced by intraperitoneal injection of 10 mg/kg morphine （continuous injection of 1 dose/day， for 7 doses） and withdrawal of morphine for 1 week. Compared with the saline control group， p-ERK was found to be increased and DUSP15 was found to be decreased. Intra-NAc infusions of AAV-DUSP15 （overexpression） not only inhibited the expression of p-ERK but also prevented morphine sensitization behavior. 【Conclusion】 DUSP15 negatively regulates ERK activation level in mouse NAc. DUSP15 agonist has a potential therapeutic effect on drug addiction.
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Objective:To explore the potential mechanisms of Panax Notoginseng Saponins （PNS） on growth inhibition of breast cancer cell line 4T1 in tumor-bearing mice by investigating the mitogen-activated protein kinase kinase kinase 1 （MEKK1）/stress activated protein kinase （SAPK）/extracellular regulated protein kinases （Erk） Kinase （SEK1）/c-Jun N-terminal kinase 1 （JNK1）/activator protein-1 （AP-1） signaling pathways. Method:The 4T1 breast cancer mice model was established. Forty-eight mice with successful modeled and randomly divided into the low， medium and high-dose PNS groups （10， 20， 40 mg·kg-1） and the model control group （12 mice in each group）. The PNS groups received intraperitoneal injection with dosage of 10 mL·kg-1， while the controlled group was given the same dosage of saline. After administration with PNS for 28 days， tumor tissues were isolated， weighed， sliced and homogenized. Tumor cell apoptosis was detected by TdT mediated-dUTP nick end labeling （TUNEL） staining. The mRNA expressions of MEKK1， SEK1， JNK1 and AP-1 in tumor tissue were detected by Real-time polymerase chain reaction（Real-time PCR）. The protein expressions of MEKK1， SEK1， JNK1 and AP-1 in tumor tissue were detected by immunofluorescence staining and Western blot. Result:Compared with model group， the tumor weights of medium-dose and high-dose PNS groups were decreased significantly （P<0.05）. TUNEL staining showed that the number of apoptotic tumor cells increased with the rise of dosage of PNS （P<0.05）. The medium-dose and high-dose PNS groups showed a significant increase in the mRNA expressions of MEKK1， SEK1， JNK1 and AP-1 as well as the protein expressions of MEKK1， SEK1， JNK1 and AP-1 in tumor tissues （P<0.05）， with statistically significant differences （P<0.05）. Conclusion:PNS could inhibit the tumor growth of breast cancer cell line 4T1 in tumor-bearing mice， which may be related to the activation of MEKK1/SEK1/JNK1/AP-1 signaling pathways.
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Objective@#To observe the effect of applying electro-acupuncture to the governor vessel on the expression of proteins in the MAPK/ERK1/2 signaling pathway.@*Methods@#Sixty-four female C57BL/6 mice were randomly divided into a sham group, a spinal cord injured (SCI) group, an acupuncture (AP) group and an electro-acupuncture (EA) group. An SCI model was induced in all of the rats except those in the sham group. The sham and SCI groups were not given any special treatment, while the AP and EA groups were treated with conventional or electro-acupuncture applied to the Dazhui (DU14) and Mingmen (DU4) acupoints in the governor vessel beginning on the day following the operation. The electrical stimulation was in dense-disperse waves at 2/100Hz frequency and 0.2mA intensity, lasted for 15 minutes daily, 5 days a week for 4 weeks . The expression of myelin basic protein (MBP), the phosphorylation of extracellular signal-regulated kinase (ERK)1/2 and the phosphorylation of protein kinase B (Akt) in the injured volume were determined using immunofluorescence and western blotting on the 3rd, 7th, 14th and 28th days after the modeling.@*Results@#Compared with the SCI group, p-ERK1/2 expression was greatly enhanced in the EA group on the 3rd, 14th and 28th days. It was also significantly enhanced in the AP group by the 28th day. Compared with the AP group, the average p-ERK1/2 expression in the EA group was significantly enhanced on the 3rd and 14th days. Compared with the SCI group, the average p-Akt of the EA group was significantly enhanced on the 14th and 28th days. The average p-Akt of the AP group had decreased significantly on the 3rd day. Compared with the SCI group, the average expression of MBP in the EA group was enhanced significantly on the 3rd, 7th and 14th days and the AP group′s average was significantly greater on the 3rd and 7th days.@*Conclusion@#Electro-acupuncture can promote the expression of MBP, the phosphorylation of ERK1/2 and the phosphorylation of Akt after spinal cord injury.
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Objective@#To analyze the changes of protein expression in aqueous humor of patients with primary open angle glaucoma (POAG), and to explore the biological markers and potential therapeutic targets associated with disease occurrence.@*Methods@#A retrospective case-control study was adopted.Ten patients with age-related cataract and 10 patients with POAG combined with cataract.were collected at the Tianjin Medical University Eye Hospital from October 2016 to December 2017.In the process of surgery, 100 μl of aqueous humor were collected with 1 ml syringe and No.1 needle through the surgical access.Those proteins extracted from aqueous humor were analyzed by quantitative proteomic mass spectrometry.The differential significance test was performed by Maxquant significances A. The differential proteins of the two groups were screened and determined with the conditions of P<0.05 and difference multiple>2.The biological big data was annotated by the function of GO and KEGG.The study was approved by the Ethics Committee of the Tianjin Medical University Eye Hospital (No.2013KY[L]-10). Patients and their guardians all signed the informed consent.@*Results@#Ninty-seven differential proteins were detected in this proteomic analysis, including 48 up-regulated proteins and 49 down-regulated proteins.GO analysis significantly differs in protein function involved in many aspects, some different proteins including lipopolysaccharide-binding protein (LBP), cluster of Differentiation 163(CD163), C-reactive protein (CRP), annexin A1 (ANXA1) were involved in inflammation; redox-related proteins were glutathione S-transferase P (GSTP1), thioredoxin (TXN), some different proteins related with cell adhesion movement were cartilage oligomeric matrix protein (COMP), desmocollin-2 (DSC2) and laminin subunit beta-2 (LAMB2); procollagen-lysine, 2-oxoglutarate 5-dioxygenase 1 (PLOD1), solid protein (tenascin, TNC) are associated with fibrosis; some different proteins related to nerve growth were reelin (RELN), semaphorin-3F(SEMA3F), semaphorin-4B(SEMA4B). Metabolism-related proteins included pyruvate kinase (PKM), carb oxypeptidase N subunit 2 (CPN2) and so on.KEGG analysis indicated that the expression of NrF2/ERK signaling pathway and TGF-β/NF-κB signaling pathway were different between the two groups.@*Conclusions@#The expression of GSTP1 and TXN in the aqueous humor of POAG is significantly decreased, which may regulate cell adhesion and activity and expression of extracellular matrix by regulating NrF2/ERK1/2 and TGF-β/NF-κB signaling pathways.GSTP1 and TXN may serve as a potential biomarker and therapeutic target of POAG.
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Bronchopulmonary dysplasia (BPD) is a common respiratory disease in premature infants characterized by alveolar and pulmonary vascular dysplasia.There are currently no effective preventive and therapeutic measures.Adrenomedullin (ADM) is a vasodilator peptide produced by endothelial and smooth muscle cells of the systemic and pulmonary circulation,which promotes alveolar growth and pulmonary angiogenesis.ADM protects the respiratory system through three signaling pathways:(1) it promotes pulmonary vascular endothelial cell proliferation through extracellular regulated protein kinases (ERK);(2) attenuates lung cell apoptosis and improves cell proliferation through protein kinase B (PKB) pathway;(3) it down-regulates NADPH oxidase 4 (NOX4) expression in lung tissue to inhibit oxidative stress and improves BPD.So ADM signaling axis may be a potential therapeutic target for human infants with BPD.It provides theoretical basis for clinical prevention and treatment of BPD in premature infants.
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Objective: To explore the effect of Helicobacter pylori virulence factor cytotoxin-associated gene A protein (CagA) on the extracellular regulated protein kinase (ERK) signaling pathway, and to elucidate the carcinogenesis mechanism of CagA. Methods: The pcDNA3. 1/CagA eukaryotic expression vector was constructed, and the gastric cancer AGS cells were divided into blank control group (blank vector transfection), CagA transfection group (GZ7/CagA transfection), and CagA + ERKi group (ERK1/2 inhibitor pretreatment + GZ7/CagA transfection). The expression levels of CagA, phosphorylated ERK (p-ERK), total ERK (T-ERK), B-lymphocytoma-2 (Bcl-2), Bcl-2-related X protein (Bax) and cleaved caspase-3 proteins in the cells in various groups were determined by Western blotting method. The activities of AGS cells in various groups were determined by CCK-8 method, and the apoptotic rates of AGS cells were determined by flow cytometry. Results: Compared with blank control group, the expression levels of CagA, p-ERK, and Bel-2 proteins in CagA transfection group were significantly increased (P<0. 01), and the expression levels of Bax and cleaved caspase-3 proteins were significantly decreased (P<0. 01). Compared with CagA transfection group, the expression levels of p-ERK and Bel-2 proteins in CagA+ERKi group were significantly decreased (P<0. 01), and the expression levels of Bax and cleaved caspase-3 proteins were significantly increased (P<0. 01). Compared with CagA transfection group, the activities of gastric cancer cells in CagA + ERKi group at different time points were significantly decreased (P< 0. 01). Compared with CagA transfection group, the apoptotic rate of gastric cancer cells in CagA + ERKi group was significantly increased (P<0. 05). Conclusion: Helicobacter pylori virulence factor CagA can inhibit the proliferation of gastric cancer cells and promote the apoptosis of gastric cancer cells, and its mechanism may be related to the activation of ERK signaling pathway by CagA.
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Objective To analyze the changes of protein expression in aqueous humor of patients with primary open angle glaucoma ( POAG ) , and to explore the biological markers and potential therapeutic targets associated with disease occurrence. Methods A retrospective case-control study was adopted. Ten patients with age-related cataract and 10 patients with POAG combined with cataract. were collected at the Tianjin Medical University Eye Hospital from October 2016 to December 2017. In the process of surgery,100 μl of aqueous humor were collected with 1 ml syringe and No. 1 needle through the surgical access. Those proteins extracted from aqueous humor were analyzed by quantitative proteomic mass spectrometry. The differential significance test was performed by Maxquant significances A. The differential proteins of the two groups were screened and determined with the conditions of P<0. 05 and difference multiple>2. The biological big data was annotated by the function of GO and KEGG. The study was approved by the Ethics Committee of the Tianjin Medical University Eye Hospital (No. 2013KY[L]-10). Patients and their guardians all signed the informed consent. Results Ninty-seven differential proteins were detected in this proteomic analysis,including 48 up-regulated proteins and 49 down-regulated proteins. GO analysis significantly differs in protein function involved in many aspects,some different proteins including lipopolysaccharide-binding protein (LBP),cluster of Differentiation 163(CD163),C-reactive protein (CRP),annexin A1 (ANXA1) were involved in inflammation;redox-related proteins were glutathione S-transferase P (GSTP1),thioredoxin (TXN), some different proteins related with cell adhesion movement were cartilage oligomeric matrix protein ( COMP ) , desmocollin-2 ( DSC2 ) and laminin subunit beta-2 ( LAMB2 );procollagen-lysine, 2-oxoglutarate 5-dioxygenase 1 (PLOD1),solid protein (tenascin,TNC) are associated with fibrosis;some different proteins related to nerve growth were reelin (RELN),semaphorin-3F(SEMA3F),semaphorin-4B(SEMA4B). Metabolism-related proteins included pyruvate kinase ( PKM ) , carb oxypeptidase N subunit 2 ( CPN2 ) and so on. KEGG analysis indicated that the expression of NrF2/ERK signaling pathway and TGF-β/NF-κB signaling pathway were different between the two groups. Conclusions The expression of GSTP1 and TXN in the aqueous humor of POAG is significantly decreased,which may regulate cell adhesion and activity and expression of extracellular matrix by regulating NrF2/ERK1/2 and TGF-β/NF-κB signaling pathways. GSTP1 and TXN may serve as a potential biomarker and therapeutic target of POAG.
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Rabdosia japonica(Burm.f.) Hara var.glaucocalyx(Maxim.) Hara is a traditional Chinese medicine, and is known to have anti-tumor effects. This study aims to investigate the effect of glaucocalyxin A (GLA), a diterpenoids extracted from Glaucocalyx Hara, on apoptosis of glioma cells and its mechanism. This study investigated the molecular signaling mechanism of GLA-induced glioma cell apoptosis by analyzing survival rate of C6 rat glioma cells, cell morphology, colony formation ability, interference ribonucleic acid, polymerase chain reaction, and Western blot. The result showed that in the presentce of GLA, the survival rate of C6 rat glioma cells decreased significantly, while the expression of guanine nucleotide-exchange factor-H1 was up-regulated, causing phosphorylation of extracellular regulated protein kinases proteins and apoptosis. Hence, the mechanism of GLA-induced glioma cell apoptosis was the GEF-H1/ERK pathway.
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Objective To investigate the effect of I1imidazoline receptor(I1R)on the expression and function of α2Aadrener-gic receptor(α2AAR)at the cellular level.Methods After sequencing and enzymatic identification,the mouse I1R and α2AAR plas-mids were transfected into CHO cells,respectively.The radioligand receptor binding assay and flow cytometry were used to select sin-gle cell clones,and the CHO cell lines stably expressing the mouse I1R or α2AAR were established.The CHO cell line that stably ex-presses both the mouse I1R and α2AAR were also established by the same technology and strategy.Then,the radioligand receptor bind-ing assay was used to determine the affinity and expression of α2AAR. Further,the effects of I1R on the α2AAR expression and the α2AAR agonist dexmedetomidine(DEX)-induced extracellular regulated protein kinase(ERK)phosphorylation were evaluated by the Western blotting.Results After transfection of mouse I1R and α2AAR plasmids,CHO cells grew normally.In the saturation binding experiments of membrane proteins from the CHO cells that stably expressed α2AAR,the Kdand Bmaxvalues of 3H-RX821002 were(0.96 ± 0.24)nmol/L and(0.29 ± 0.03)nmol/g protein,respectively.The expression levels of I1R were significantly increased in both the CHO cells expressing I1R and the CHO cells co-expressing α2AAR and I1R(P<0.05,P<0.01),when the cells that express exogenous I1R or α2AAR alone were trasfected again with the I1R plasmids.Moreover,in the CHO cells that transfected both I1R and α2AAR sta-bly,the I1R expression upregulated the α2AAR expression(P<0.01),and further increased the ERK phosphorylation induced by DEX through activating α2AAR(P<0.01).Conclusion I1R could upregulate the α2AAR expression and the ERK phosphorylation in-duced by DEX through activating α2AAR in the CHO cells that express exogenous I1R and α2AAR.This study presents a groundwork for further exploration of the relationship between I1R and α2AAR at the molecular level in future.
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<p><b>OBJECTIVE</b>To explore the regulatory mechanism of inducible nitric oxide synthase (NOS-2) expression related to proliferation of Tca8113 cells.</p><p><b>METHODS</b>RNAi mediated by short hairpin RNAs was utilized to knock down NOS-2, protein kinase C (PKC)-α, PKC-β and PKC-δ. Griess Reagent played a significant role on the detection of NO product after NOS-2 silence. The cell proliferation was determined by CCK8 method. Quantitative real-time polymerase chain reaction (q-PCR) was recruited to check the mRNA level of NOS-2, PKC-α, PKC-β and PKC-δ after treated by a variety of ways. Eventually, the measure of phosphorylation of extracellular regulated protein kinases (ERK)1/2 was performed by Western blotting in PMA-treated Tca8113 cells.</p><p><b>RESULTS</b>The cell viability of Tca8113 decreased obviously after transfected with NOS-2 siRNA (P<0.01). PKC reduced the expression level of NOS-2 mRNA (P<0.05). PKC-α, PKC-β and PKC-δ worked together to regulate the level of NOS-2 mRNA (P<0.01). Motigen-activated protein kinase kinase (MEK)/ERK signaling pathway regulated the level of NOS-2 mRNA negatively (P<0.05). PKC down regulated the level of NOS-2 mRNA through MEK/ERK signaling pathway (P<0.05).</p><p><b>CONCLUSIONS</b>PKC regulates the mRNA level of NOS-2 related to proliferation through MEK/ERK signaling pathway in Tca8113 cells.</p>
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Objective@#To explore the effect and mechanism of over-expression of miR-17-92 gene cluster on the biological characteristics of prostate cancer cells.@*Methods@#DU145 cells were transfected with miR-17-92 gene expression plasmid and clones with stable ectopic miR-17-92 overexpression were established. The cell viabilities of DU145-17-92 and DU145-control cells were monitored by xCELLigence system. Cell proliferation and apoptosis were analyzed by Ki-67 and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. Cell cycle was detected by flow cytometry. Expression levels of proteins involved in apoptosis and Akt pathway were determined by western blotting.@*Results@#xCELLigence RTCA array data showed that the growth rate of DU145-17-92 cells was significantly higher than that of DU145-control cells after 24 h of seeding (P<0.01). The Ki-67-positive rates of the DU145-control group at 24, 48 and 72 hours were (56.57±1.68)%, (85.48±0.26)% and (90.85±2.08)%, respectively. While the Ki-67 positive rates of the DU145-17-92 group at the desired time points were (73.64±0.68)%, (93.43±1.23)% and (97.36±0.86)%, respectively, with a statistically significant difference at 24 hours (P<0.01). The percentages of apoptotic cells of the DU145-control group at 24, 48 and 72 hours were (6.76±0.09)%, (14.51±0.86)% and (20.73±1.64)%, respectively, while the apoptotic percentages of the DU145-17-92 group were (1.86±0.15)%, (7.90±0.40)% and (4.92±0.48)%, respectively. The percentages of apoptotic cells of the DU145-control group at different time were significantly higher than those of DU145-17-92 group (P<0.01 for all). The result of western blotting showed that the protein expression levels of Bcl-2 interacting mediator of cell death (BIM) and phosphatase and tensin homolog deleted on chromosome ten (PTEN) in DU145-control cells were 0.83±0.00 and 0.91±0.00, respectively, significantly higher than 0.16±0.00 and 0.13±0.00 of DU145-17-92 cells (both P<0.01). Overexpression of miR17-92 induced the phosphorylation of protein kinase B (Akt) at Ser473 while no appreciable effect on the phosphorylation of Akt at Thr308. The phosphorylated level of extracellular regulated protein kinases (ERK) in DU145-control cells was 0.21±0.01, significantly lower than 0.72±0.01 of DU145-17-92 cells (P<0.01).@*Conclusions@#Overexpression of miR-17-92 gene plays a pivotal role in growth, proliferation, apoptosis and cell cycle of DU145 cells through down-regulation of apoptotic protein BIM and tumor suppressor PTEN and activation of Akt and ERK signaling pathway.
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Objective To investigate the relationship of extracellular regulated protein kinases activation and neural cells autophagy in rats after subarachnoid hemorrhage.Methods One hundred twenty male SD rats were randomly divided into sham operated group,SAH group,ERK1/2 inhibitor U0126 group,autophagy inducer rapamycin (Rap) group.The animal models were established by injecting the autologous blood into cisterna magna twice.U0126 (5μ g/μL) and Rap (10nmol/μL) were injected into lateral ventricles in U0126 group and Rap group 30min before SAH.The morphology of hippocampal nerve cells were examined by using light microscopy.The expression levels of phosphorylated ERK 1/2 (p-ERK 1/2),ERK 1/2mRNA and autophagy markers (Beclin-1 and Beclin-1 mRNA、LC3-Ⅱ and LC3mRNA) in the hippocampus were detected by using inmunohistochemistry and real-time fluorescence quantitative PCR.Result Compared with sham group,the rate of dead nerve cells,the mRNA levels of ERK1/2,Beclin-1 and LC3 as well as the levels of the p-ERK1/2,Beclin-1 and LC3-Ⅱ increased in SAH group (P＜0.05).Compared with SAH group,the rate of dead nerve cells increased(P＜0.05),the ERK1/2 mRNA,Beclin-1 mRNA and LC3 mRN A,and p-ERK1/2,Beclin-landLC3-Ⅱ in U0126 group decreased(P＜0.05);the rate of dead nerve cells decreased (P＜0.05),the Beclin-1 mRNA and LC3 mRNA,the Beclin-1and LC3-Ⅱ level increased in Rap group(P＜0.05),but ERK 1/2 mRNA and p-ERK 1/2 remained unchanged (P＞0.05).Conclusion Activation of the ERK1/2 signaling pathway after SAH,can induce nerve cells death by increasing Beclin-1 and LC3-Ⅱ expressions.
ABSTRACT
Objective To explore the effect of extracellular regulated protein kinases (ERK) signaling pathway on early brain injury and autophagy of nerve cell in hippocampus area in rats with subarachnoid hemorrhage (SAH). Methods Forty-eight adult male Sprague-Daw-ley rats were randomly divided into sham group, SAH group, SAH+dimethyl sulfoxide (DMSO) group and SAH+U0126 group, with 12 rats in each group. The SAH model was established with puncture of internal carotid artery. The SAH+U0126 group was injected with U0126 0.05 mg/kg;the sham group and SAH group were injected with normal saline, and the SAH+DMSO group was injected with DMSO 30 min-utes before modeling. They were sacrificed 24 hours after modeling. The brain water content was measured with wet and dry method. The morphology changes of neural cells in hippocampus CA1 were observed by HE staining. The expression of phosphorylation ERK (p-ERK), Beclin-1 and LC3-Ⅱwere detected with immunohistochemical method and Western blotting. Results Compared with the sham group, the brain water content increased (P0.05). Conclusion The activation of ERK signaling pathway may alleviate early brain injury after SAH by regulation of autophagy.
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Objective To investigate the influence of recombinant neuregulin-1 beta (rhNRG-1β) on neural stem cell proliferation through extracellular regulated protein kinases (ERK) signaling pathway in oxygen and glucose deprivation (OGD) environment.Methods Neural stem cells were obtained from embryonic brain of mice pregnant for 14-17 d,cultured and identified by immunochemical staining through detection of the indicator nestin using the SABC-FITC (POD)double standard kit.Neural stem cells were divided into three experiment groups (OGD group,control group and OGD + rhNRG-1β group).Control group:identified neural stem cells,2 × 107,were cultured for 3 h in the 24-hole culture plate with DMEM/F12 complete culture medium;OGD group:neural stem cells,2 × 107,were cultured in the 24-hole culture plate deprived glucose DMEM/F12 in a wet airtight container (37 ℃ constant temperature),cells were cultured with mixed gas of nitrogen (950 ml/L) and oxygen (50 ml/L) for 1 h,and then the culture medium was replaced with complete culture medium and cultured for 3 h;OGD + rhNRG-1β group:before OGD intervention,100 μg/L rhNRG-1β was given for 3 h.Neurospheres formation:the three groups of stem cells were dispersed into single cells,1 × 106/ml cells were inoculated to culture plates containing cover slips coated with poly lysine,and cultivated for 7 d,and neurospheres formation of the 3 groups of neural stem cells was observed under microscope,which was aimed to record neural stem cells proliferation changes.Colony formation:the three groups of stem cells,vaccinated in 60 mm in a petri dish,2 × 107 in number,were cultivated in complete culture medium for 24 h.The colony formation of the three groups of cells was observed under microscope,and neural stem cells proliferation changes were observed.Western blotting:the change of phosphorylation ERK (pERK) protein of the three groups of stem cells was determined,and the effect of pERK protein expression regulated by rhNRG-1β in mice neural stem cells proliferation through ERK signaling pathway was observed.Results Microscopically the primary cultured stem cells grew in single or in pairs,in a round shape;neural stem cell proliferated in clumps or colony;neural stem cells expressed the specificity of nestin protein markers with fluorescent yellow-green color.The differences in the aspects of the average diameter of neurospheres and neurospheres quantity in the neural stem cells between groups were statistically significant (F =693.66,1 002.09,all P ＜ 0.01),and among them the neuropheres formation of OGD group was significantly suppressed.Formation quantity and average diameter in OGD group [(88.78 ± 7.14) numbers,(62.12 ± 2.52) μm] were significantly lower than those in the control group [(246.34 ± 8.67) numbers,(128.45 ± 2.33) μm] and those in OGD + rhNRG-1β group [(237.87 ± 6.61) numbers,(118.37 ± 2.71) μm,all P ＜ 0.01].The difference of colony formation rate of neural stem cell was statistically significant (F =132.03,P ＜ 0.01),and among them colony formation of OGD group significantly suppressed.Formation rate in OGD group [(11.65 ± 0.94)％] was significantly lower than that in the control group [(33.23 ± 2.93)％] and that in OGD + rhNRG-1β group [(31.42 ± 2.61)％,all P ＜ 0.01].Western blotting showed that the difference of pERK protein expression of neural stem cells between groups was statistically significant (F =63.76,P ＜ 0.01).Relative expression of the pERK protein in OGD group (0.487 ± 0.072) was significantly lower than that in the control group (1.013 ± 0.112) and that in OGD + rh-NRG-1β group (1.752 ± 0.278,all P ＜ 0.01).Conclusion rhNRG-1β preserves neural stem cell proliferation with phosphorylation ERK protein expression up-regulated in oxygen and glucose deprivation environment.
ABSTRACT
ObjectiveFrom the changes of expression of cold-inducible RNA-binding protein (CIRP) in rats with traumatic brain injury under mild hypothermia treatment with Shenfu decoction as a subsidiary, to speculate the mechanism of protective effect of the decoction on the injury.Methods Ninety Sprague-Dawley (SD) rats were divided into three groups by random number table: non-transfection control group, adenovirus mediated immune flourescent reverse transcription virus group (blank AD5-GFP transfection group) and adenovirus mediated immune flourescent reverse transcription virus carrying CIRP silent expression gene group (AD5-GFP-CIRP-SiRNA transfection group), 30 rats in each groups. Then, each group was subdivided into three subgroups: model group, traditional Chinese medicine (TCM) low and high dose groups, 10 rats in each subgroup. After the mild hypothermia treatment for 48 hours, in the TCM low dose group and high dose group, a dose of TCM 1 mL/kg and 5 mL/kg was injected via a tail vein into the rat respectively, while in the model group, 1 mL/kg normal saline was injected into the same vein, once a day for consecutive 2 days in all the groups. Before modeling in the blank AD5-GFP transfection group and AD5-GFP-CIRP-SiRNA transfection group, virus transfection models were reproduced at first by one-time intrathecal injection of 0.1 mL AD5-GFP and 0.1 mL (1×1010 pfu/mL) AD5-GFP-CIRP-SiRNA virus vector respectively, and in model group, 0.1 mL normal saline was given. The rat cortex, hippocampus and hypothalamus part were collected, the brain cell apoptosis was detected by transferase-mediated deoxyuridine triphosphate-biotin nick end labeling (TUNEL), the CIRP mRNA expression in the cortex, hippocampus and hypothalamus part was measured by reverse transcription-polymerase chain reaction (RT-PCR), the protein expressions of rat sarcoma protein Raf, Ras, extracellular signal-regulated kinase (ERK), phosphorylation ERK (p-ERK), mitogen activated protein kinase (MEK), p-MEK were determined by Western Blot.Results The brain tissue cell apoptosis indexes (AI) in the cortex, hippocampus and hypothalamus part in TCM low, high dose group of non-transfection control and blank AD5-GFP transfection group were lower than those in model group, and the expressions of CIRP mRNA were higher than those in model group, there were no significant differences in AI and CIRP mRNA in the cortex, hippocampus and hypothalamus between model, TCM low and high dose groups of AD5-GFP-CIRP-SiRNA transfection group, but AI was significantly higher and CIRP mRNA was significantly lower than that in corresponding subgroups of AD5-GFP transfection control group and blank AD5-GFP transfection group. Western Blot detection showed that: Raf/Ras, p-MEK/MEK protein expressions revealed no statistical significant differences in different parts of each group (allP > 0.05), the p-ERK/ERK protein expression in the cortex, hippocampus, and hypothalamus part was significantly lower in TCM low and high dose group than that in the model group of non-transfection control group and blank AD5-GFP transfection group, the degree of descent in the TCM high dose group being more significant (the cortex: non-transfection control group was 7.2±1.0 vs. 15.3±1.8, AD5-GFP transfection group was 8.1±0.7 vs. 16.2±1.5; hippocampus part: non-transfection control group was 6.6±0.8 vs. 14.7±2.0, AD5-GFP transfection group was 6.8±1.0 vs. 14.9±1.3; hypothalamus part: non-transfection control group was 9.4±1.1 vs. 12.7±1.7, AD5-GFP transfection group was 10.6±1.3 vs. 9.4±1.1, allP 0.05).Conclusions The Shenfu decoction used in rats with brain trauma under treatment of mild hypothermia is possibly by promoting CIRP over-expression, lowering ERK expression and inhibiting the initiation of signal transduction of the secondary transcription factor phosphorylation, thereby the neural cell apoptosis is decreased and play a subsidiary role of anti-apoptosis of mild hypothermia.