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Objective To investigate the roles of glutamate signaling pathway in the activation of human peripheral blood lymphocytes(PBLs) and pathogenesis of vitiligo.Methods Peripheral blood lymphocytes (PBLs) isolated from 5 patients with generalized vitiligo and 5 healthy controls were cultured in vitro.Flow cytometry was performed to quantify the expression of CD25 and interferon-γ on PBLs derived from healthy controls and treated with MK801 (a non-competitive antagonist of N-methyl-D-aspartic acid receptor,NMDAR) at 100 μmol/L or phosphate buffered saline (PBS) for 48 hours,as well as the level of reactive oxygen species (ROS) in the controlderived PBLs treated with MK801 at 100 μmol/L,NMDA (an agonist of N-methyl-D-aspartic acid receptor) at 0.5 mmol/L or PBS for 48 hours.The protein and mRNA expressions of NMDAR1 and NMDAR2A were measured by flow cytometry and real-time PCR,respectively,in PBLs from the healthy controls and vitiligo patients.Immunohistochemistry was used to observe the expressions of NMDAR1 and NMDAR2A in tissue specimens from depigmented and postinflammatory hyperpigmentation lesions of the patients with vitiligo and from normal skin of the healthy controls.Results Compared with the PBS-treated PBLs from the healthy controls,the MK801-treated PBLs showed a downregulated expression of CD25 (7.28% ± 0.18% vs.16.02% ± 0.42%,P < 0.01),but an upregulated proportion of CD25+IFN-γ+ lymphocytes (1.79% ± 0.09% vs.0.78% ± 0.06%,P < 0.01),and the NMDA-treated PBLs displayed a higher ROS level (101.1 ± 3.50 vs.69.80 ± 2.08,P< 0.01 ).The protein expression of NMDAR1 in PBLs was significantly higher in vitiligo patients than in the healthy controls (3.85 ± 2.17 vs.0.97 ±0.55,P < 0.05).Conclusion Glutamate signaling pathway may be involved in the immunopathogenesis of vitiligo via affecting the secretion of interferon-γ by,and ROS level in,activated lymphocytes.
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Objective To investigate the action mechanism of glutamate-mediated signaling pathway in malignant melanoma. Methods WM451LU melanoma cells in log phase were classified into 6 groups, negative control group treated with PBS (100 μl), MK801 group treated with the non-competitive N-methyl-D-aspartate (NMDA) receptor antagonist MK-801 (100 μmol/L), CPCCOEt group treated with non-competitive metabotropic glutamate receptor 1 (mGluR1) antagonist CPCCOEt, MAP2 group transfected with adenovirus vector containing microtubule associated protein 2a (Ad-MAP2a), MK801 + MAP2 group treated with MK801 of 100 μmol/L and transfected with Ad-MAP2a, CPCCOEt + MAP2 group treated with CPCCOEt of 10 μmol/L and transfected with Ad-MAP2a. Western blot was performed to detect the expression of an ionotropic glutamate receptor, i.e., N-methyl-D-aspartate receptor type 2A (NMDAR2A) in WM451LU cells transfected with Ad-MAP2a. Scratch motility assay and cell invasion assay were conducted in vitro to detect the changes in migration and invasion ability of WM451LU cells after treated with Ad-MAP2a, MK-801, CPCCOEt alone or in combination. In vivo study was carried out to compare the inhibitory effect of the above treatments on melanoma. Results Western blot revealed a decrease in the expression of NMDAR2A in WM451LU cells after transfected with Ad-MAP2a. The scratch motility assay showed that the number of migrating cells per high power field was 117.04 ± 2.76 in MAP2 group,107.64 ± 6.50 in MK801 group,97.36 ± 4.79 in CPCCOEt group, 43.28 ± 3.02 in MK801 + MAP2 group,30.76 ± 3.97 in CPCCOEt + MAP2 group,significantly different from that in the negative control group (152.3 ± 5.75,all P < 0.01 ). Cell invasion assay demonstrated that the average number of invading cells per high power field in the negative control was significantly higher than that in MAP2 group, MK801 group, CPCCOEt group, MK801+MAP2 group and CPCCOEt + MAP2 group (170.43 ±8.72 vs. 98.26 ± 3.84, 97.22 ± 5.54, 112.23 ± 7.21, 42.89 ± 5.06, 58.25 ± 6.68, P < 0.05, 0.05, 0.05, 0.01and 0.01, respectively).A significant decrease was observed in the average volume of experimental melanoma in mice of MAP2 group, MK801 group, MK801 + MAP2 group, CPCCOEt group and CPCCOEt + MAP2 group compared with the negative control group (224.02 ± 46.19 mm3, 160.33 ± 33.91 mm3, 91.49 ± 21.48 mm3,202.30 ± 52.37 mm3, 111.13 ± 69.81 mm3 vs. 342.70 ± 60.92 mm3, all P < 0.01 ). Conclusions To block the glutamate signaling pathway in vitro can inhibit the invasion and migration of melanoma cells, and to block the pathway in vivo can inhibit the growth of malignant melanoma and alter the morphology of melanoma cells.
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ObjectiveTo investigate the effect of FUT8-siRNA on transforming growth factor β (TGF-β)-Smad2/3 signalling pathway in renal tubular epithelial cells.MethodsHK-2 cells were divided into six groups:normal group,negative control group,TGF-β1 group,TGF-β1 with FUT8 interference group,TGF-β1 with negative control group,FUT8 interference group.RNAi was performed to silence the expression of FUT8 gene,then immunofluorescent analysis was used to detect the expression of core fucose in the HK-2,immunoprecipitation and lectin blotting were performed to detect the core fucosylation of TGF-βR Ⅱ and ALK-5,and detect the change of Smad2/3 and p-Smad2/3 in HK-2 cells after FUT8 gene was silenced.ResultsCompared with the normal and negative control group,incubation with 5 μg/L TGF-β1 for 48 h could significantly up-regulate the core fucosylation of HK-2 cells,enhance the protein expression of TGF-βR Ⅱ and ALK-5 (P<0.05),markedly increase the expression level of p-Smad 2/3 (P<0.05) and cause it to nuclear translocation in HK-2 cells.While FUT8siRNA could inhibit the above up-regulation of TGF-βR Ⅱ and ALK-5(P<0.05),suppress the increase of p-Smad 2/3(P<0.05) and its nuclear translocation without disturbing the protein expression of TGF-βR Ⅱ and ALK-5.Conclusion FUT8-catalized core fucosylation of TGF-βR Ⅱ and ALK-5 is needed to fulfill their functions,and blocking core fucosylation of TGF-βR Ⅱ and ALK-5 leads to the inhibition of TGF-β-Smad2/3signalling pathway in HK-2 cells.
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Objective To investigate the effects of glutamate receptor signaling on melanoma cell dendrite morphology and cytoskeleton protein. Methods A metastatic human malignant melanoma cell line WM451LU was cultured and transfected by recombinant adenovirus vector carrying a cDNA encoding microtubule-associated protein 2a (MAP2a). MK-801, an antagonist of N-methyl-D-aspartate receptor (NMDAR), and CPCCOEt, an antagonist of metabotropie glutamate receptor 1 (mGluR1), were used to treat transfected or untrausfeeted WM451LU cells. Confocal microscopy and three dimensional atomic force microscopy were used to assess subcellular location of NMDAR2A, mGluR1 and MAP2a as well as the dis-tribution of α-tubulin in and dendrite morphology of WM451LU cells. The proliferation of WM451LU cells was estimated by cell survival growth curve. Results Confocal laser microscopy revealed that NMDAR2A, mGluRl and MAP2a were mainly co-localized in melanoma cell dendrites. Both MK-801 and CPCCOEt increased the density of microtubules in cell dendrites and dendritic branching of WM451LU cells, and both effects of MK-801 and CPCCOEt were enhanced by the expression of MAP2a. Furthermore, the proliferation of WM451LU cells was significantly inhibited by MK-801 of 100 μmol/L and CPCCOEt of 10 μmol/L. Conclusions In melanoma cells, glutamate receptors may participate in the development of dendrites, and anta- gonists of glutamate receptors could inhibit the proliferation of melanoma cells.
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Objective To explore the role of p170, MRP, bcl-2 in clinical drug- resistance and their correlation. Methods There are 44 acute leukemia(AL) patients, among them ANLL is 29, ALL is 15.The expression of p170, MRP, bcl-2 were detected. At last, the patients were divided into two groups: CR and NR according to efficacy after two periods standard chemotherapy. Results Overexpression of p170, MRP,bcl-2 were found in AL (P <0.05). The expression of p170 and MRP were lower in CR group than that in NR groups in AML and ALL; there were 22 of 24 patients expressed one or two proteins in NR groups and the expression of p170 in patients was concordant with that of MRP to certain extent (P <0.01). The overexpression of bcl-2 was related with the worse prognosis. The expression of bcl-2 was lower significantly in CR group than in CR and NR (P<0.05). Conclusion p170, bcl-2, MRP are all associated with clinical MDR. High expression of these proteins is an unfavorable factor to prognosis. The expression of MRP and p170 showed coincidence, but showed no significance with expression of bcl-2 in untreated patients, it indicated that the drug-resistance mediated by p170 was different from bcl-2.