Biomedical subjects

Peng-Yuan Yang

Publications and source records attributed to Peng-Yuan Yang.

24 records · Page 2Linked to original sources

PubMed2003

Intercellular adhesion molecule-1 and vascular endothelial growth factor expression kinetics in macrophage-derived foam cells.

Macrophage-derived foam cells seem to play an important role during inflammatory response of atherosclerosis, in which the overexpression of intercellular adhesion molecule-1 (ICAM-1) and vascular endothelial growth factor (VEGF) are associated with the early and later pathological changes in foam cell formation. In this study, we investigated the expression kinetics of ICAM-1 and VEGF in macrophage-derived foam cells. The foam cell model was established through incubating the human monocyte line (U937 cells) with oxidized-low density lipoprotein (ox-LDL). Up-regulated expressions of ICAM-1 and VEGF were analyzed in protein and mRNA levels in U937 foam cells by flow cytometry, ELISA, and Northern blot. Kinetic studies showed the deferent kinds of expression curves in dose response and time course. The expression dose-kinetics demonstrated that the ICAM-1 showed the peak expression induced by ox-LDL 50 mg/L, while VEGF levels increased in a dose-dependent manner with the maximum level induced by ox-LDL 200 mg/L. Time-kinetic studies revealed that the ICAM-1 levels showed the peak expression in 12 h while VEGF expression increased in a time-dependent manner with the maximum level in 48 h. These results proved that both ICAM-1 and VEGF expressions were enhanced in the macrophage-derived foam cells, but ICAM-1 expression increased earlier than the up-regulation of VEGF; low dose of ox-LDL mainly up regulated ICAM-1 expression, while high dose mainly increased the VEGF expression.

Blotting, Northern↗

PubMed2003

Proteomic studies of macrophage-derived foam cell from human U937 cell line using two-dimensional gel electrophoresis and tandem mass spectrometry.

SUMMARY: The authors have identified 37 proteins in the whole-cell extracts from human monoblastic leukemia (U937) cell and macrophage-derived foam cell. The in vitro foam cell model was established by incubating the human U937 cells with oxidized low-density lipoprotein. The global changes in protein expressions between U937 foam cell and normal U937 cells were measured with two-dimensional polyacrylamide gel electrophoresis, and some proteins were trypsin-digested and then identified through tandem mass spectrometry after capillary liquid chromatography separation. Some of the identified proteins were validated via Internet links to the U937 proteomic map provided on the Expasy proteomics server. The experimental data can provide potential markers for atherosclerotic studies.

Electrophoresis, Gel, Two-Dimensional↗

PubMed2003

Antisense oligodeoxynucleotide inhibits vascular endothelial growth factor expression in U937 foam cells.

AIM: To study the expression of vascular endothelial growth factor (VEGF) induced by oxidized low density liporotein (ox-LDL) and the inhibitory effects of antisense oligodeoxynucleotide (asODN) on the levels of VEGF protein and mRNA in the U937 foam cells. METHODS: U937 cells were incubated with ox-LDL 80 mg/L for 48 h, then, the foam cells were treated with asODN (0, 5, 10, and 20 micromol/L). The VEGF concentration in the media was determined by ELISA. The VEGF protein expression level in cells was measured by immuohistochemistry; the positive ratio detected by a morphometrical analysis system was used as the amount of the VEGF expression level. The VEGF mRNA level was examined by Northern blotting. RESULTS: After U937 cells were incubated with ox-LDL, VEGF expression level increased greatly both in the cells and in the media. asODN markedly inhibited the increase of VEGF. After treatment with asODN 20 micromol/L, the VEGF protein concentration in the media decreased by 45.0%, the VEGF positive ratio detected by immuohistochemistry in cells decreased by 64.9%, and the VEGF mRNA level decreased by 47.1%. CONCLUSION: The expression of VEGF in U937 foam cells was strong. asODN inhibited VEGF expression significantly in U937 foam cells in vitro.

Foam Cells↗

PubMed2003

Protein expressions in macrophage-derived foam cells: comparative analysis by two-dimensional gel electrophoresis.

AIM: To study the overall protein expression changes induced by oxidized low-density lipoprotein (ox-LDL) in the U937 foam cells. METHODS: Foam cell model was established by incubating the human monoblastic leukemia (U937) cells with ox-LDL. Each protein samples in U937 control cells and U937 foam cells were separated by two-dimensional gel electrophoresis (2-DE). After the gels were stained by silver staining method, the images were analyzed by PDquest 2D-image-analysis software (Bio-Rad). Some of the spots were available via the Internet with links to the U937 proteomic map provided from the ExPASy Proteomics server. RESULTS: Using 2-DE, the overall protein map was obtained, in which 150 spots were matched with the control gel (match ratio: 75 %). Compared with U937 cells, 37 spots significantly changed in the foam cells (P<0.05), among which the expression levels in 28 spots increased and those in 9 spots decreased. Especially, 8 spots in U937 cells were absent in the foam cells, while 11 spots in the foam cells were absent in the control cells. CONCLUSION: The changed protein profiles induced by ox-LDL in U937 foam cells were established to support the functional studies on the macrophage-derived foam cells in atherosclerotic pathological states.

Cells, Cultured↗

PubMed2002

Expression of intercellular adhesion molecule-1 in U937 foam cells and inhibitory effect of imperatorin.

AIM: To investigate the expression level of intercellular adhesion molecule-1 (ICAM-1) in a macrophage-derived foam cell model from human U937 cell line and the inhibitory effect of imperatorin (IMP) on the ICAM-1. METHODS: U937 cells were incubated with oxidized low density lipoprotein (ox-LDL) 80 mg/L for 48 h and a macrophage-derived foam cell model was established. The medium was pretreated with different concentrations of IMP (0, 25, 50, 100 micromol/L). ICAM-1 protein expression in cells was measured with Western blotting; ICAM-1 mRNA level in cells was measured by Northern blotting. RESULTS: After incubated with ox-LDL, ICAM-1 expression level increased greatly. The increase in ICAM-1 protein level and mRNA level was estimated to be about 15-fold and 10-fold. When the cells were pretreated with imperatorin (50, 100 micromol/L), the increase of ICAM-1 in foam cells were remarkably inhibited. Especially when pretreated with IMP 100 micromol/L, the ICAM-1 protein level decreased by 79 % and the mRNA level decreased by 74 % each compared to the level of foam cells. CONCLUSION: After incubated with ox-LDL in vitro, the U937 foam cells showed an enhanced ICAM-1 expression compared with normal U937 cells. IMP could inhibit the expression of ICAM-1 in U937 foam cells.

Angelica↗

PubMed2002

Inhibitory effects of Ginkgo biloba extract on vascular endothelial growth factor in rat aortic endothelial cells.

AIM: To study the protective effects of Ginkgo biloba extract (GbE) against rat aortic endothelial cells (RAEC) damage induced by lysophosphatidylcholine (LPC). METHODS: Cell injury were determined by MTT assay and LDH release. Vascular endothelial growth factor (VEGF) protein production from RAEC was determined by enzyme-linked immunosorbent assay (ELISA). VEGF mRNA expression was examined by in situ hybridization and dot blot. RESULTS: GbE 0.01-1 microg/L prevented LPC-induced injury in cultured RAEC in a concentration-dependent manner. Cultured RAEC could express VEGF protein and VEGF mRNA was induced by LPC 5 mg/L. GbE could inhibit the expression of VEGF protein and VEGF mRNA in co-cultured RAEC with LPC. CONCLUSION: LPC could induce a strong expression of VEGF in RAEC. GbE could protect RAEC against the LPC-induced damage and downregulate VEGF protein and VEGF mRNA expression in cultured RAEC.

Animals↗