ABSTRACT
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.
ABSTRACT
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.
ABSTRACT
Objective To investigate the relationship between plasma glucose transporter (Glut) expression and ERK in diabetic patients with obesity. Methods Subjects in this study included type 2 diabetes (T2DM ) with overweight or obesity(T2DM+ OB/OW group ,n=20) ,T2DM with normal weight (T2DM group ,n=22) ,normal glucose with overweight or obesity(OB/OW group ,n=20) ,normal glucose with normal weight (NC group ,n=21). Automatic biochemical analyzer was used to detect the glucose concentrations ;colorimetry was used to detect blood lipid;ELISA was used to detect the level of insulin;Western blot was used to evaluate the expression of Glut1 Glut2 and Glut4 ;RT‐PCR was used to evaluate the mRNA expression of Glut2 ,Glut4 and ERK. Results Fasting plasma glucose (FPG )and two‐hour postprandial plasma glucose (2 hPG)in group T2DM+ OB/OW[(8.9 ± 3.7) ,(20.1 ± 3.5)mmol/L]and T2DM[(9.3 ± 2.8) ,(18.48 ± 4.59)mmol/L]were higher than in group OB/OW[(4.10 ± 0.90) ,(6.60 ± 0.75)mmol/L ]and NC[(3.9 ± 0.7) ,(6.7 ± 0.8)mmol/L](P<0.01).Hemoglobin A1c(HbA1c) in group T2DM+ OB/OW [9.90 ± 3.19)% ] and T2DM [(8.68 ± 2.75)% ] were higher than in group OB/OW [5.05 ± 0.37)% ] and NC[(5.47 ± 0.59)% ](P<0.01).FIns in group OB/OW [(7.98 ± 2.01)μIU/ml] were higher than in T2DM group[(5.91 ± 3.02)μIU/ml]and NC[(5.49 ± 1.36)μIU/ml](P< 0.05).Total cholesterol and triglyceride in T2DM + OB/OW group[(5.06 ± 0.97) ,(3.52 ± 2.68)mmol/L] , T2DM[(5.13 ± 1.27) ,(3.79 ± 3.56)mmol/L]and OB/OW[(4.67 ± 0.83) ,(1.87 ± 0.95)mmol/L]were higher than in group NC[(3.51 ± 0.89) ,(1.41 ± 1.21)mmol/L](P<0.01). Glut1 Glut2 ,Glut4 expression in T2DM+OB/OW group ,T2DM were lower than those in group OB/OW ,NC.Glut2 expression in T2DM+ OB/OW group was significantly lower than in T2DM group.Glut2 and Glut4 mRNA expression in group T2DM+ OB/OW ,T2DM were significantly lower than in group OB/OW ,NC.ERK mRNA expression in group T2DM + OB/OW ,T2DM were significantly higher than those in group OB/OW and NC.Conclusion Glut1 ,Glut2 and Glut4 expression are lower in diabetic patients with obesity ,and there is a negative correlation between the expression of ERK and Glut2 and Glut4.