摘要
To study whether the diacylglycerol (Dia) signaling pathway is stimulated by advanced glycosylation end products (AGEP) and to test the effect of vitamin E and aminoguanidine (AG) on the elevation of Dia induced by AGEP in cultured human umbilical vein endothelial cells (HUVECs) Methods The effects of AGEP on Dia levels in cultured HUVEC were studied with radio enzymatic assay Quantitative measurements of 32 P phosphatidic acid were achieved by thin layer chromatography and autoradiography Results The Dia levels in HUVECs were increased by AGEP modified bovine serum albumin (AGEP BSA) in a dose dependent, biphasic manner The early phase was rapid and transient, peaking at 15?s; the late phase reached the maximal level at 10?min and then decayed slowly Dia levels in HUVEC exposed to different concentrations (50, 100 and 200?mg/L) of AGEP BSA (341±14, 678±16, and 873±18?pmol/L, respectively vs control 225±10?pmol/L) and AGEP BSA samples with various glycosylation times (4, 8 and 12 weeks) were significantly increased (270±12, 394±16, and 556±19?pmol/L) as compared with the controls 50 and 100?mmol/L of vitamin E can reduce AGEP BSA induced Dia levels from 873±18?pmol/L to 764±29 and 441±21?pmol/L in HUVEC, respectively In AG treated (100?mmol/L) groups, the same concentration (100 and 200?mg/L) of AGEP BSA induced elevation of Dia was decreased to 312±8 and 351±13?pmol/L, respectively Glycosylated low density lipoprotein (LDL) did not affect Dia levels Conclusion AGEP causes a robust stimulation of the Dia/protein kinase C pathway in HUVEC Vitamin E can attenuate the AGEP BSA induced elevation of Dia levels AG can suppress the ability of AGEP BSA to increase Dia levels in HUVEC
To study whether the diacylglycerol (Dia) signaling pathway is stimulated by advanced glycosylation end products (AGEP) and to test the effect of vitamin E and aminoguanidine (AG) on the elevation of Dia induced by AGEP in cultured human umbilical vein endothelial cells (HUVECs) Methods The effects of AGEP on Dia levels in cultured HUVEC were studied with radio enzymatic assay Quantitative measurements of 32 P phosphatidic acid were achieved by thin layer chromatography and autoradiography Results The Dia levels in HUVECs were increased by AGEP modified bovine serum albumin (AGEP BSA) in a dose dependent, biphasic manner The early phase was rapid and transient, peaking at 15?s; the late phase reached the maximal level at 10?min and then decayed slowly Dia levels in HUVEC exposed to different concentrations (50, 100 and 200?mg/L) of AGEP BSA (341±14, 678±16, and 873±18?pmol/L, respectively vs control 225±10?pmol/L) and AGEP BSA samples with various glycosylation times (4, 8 and 12 weeks) were significantly increased (270±12, 394±16, and 556±19?pmol/L) as compared with the controls 50 and 100?mmol/L of vitamin E can reduce AGEP BSA induced Dia levels from 873±18?pmol/L to 764±29 and 441±21?pmol/L in HUVEC, respectively In AG treated (100?mmol/L) groups, the same concentration (100 and 200?mg/L) of AGEP BSA induced elevation of Dia was decreased to 312±8 and 351±13?pmol/L, respectively Glycosylated low density lipoprotein (LDL) did not affect Dia levels Conclusion AGEP causes a robust stimulation of the Dia/protein kinase C pathway in HUVEC Vitamin E can attenuate the AGEP BSA induced elevation of Dia levels AG can suppress the ability of AGEP BSA to increase Dia levels in HUVEC
