The aim of the present study was to investigate the effect exerted by low-density lipoprotein (LDL) modified by homocysteine (Hcy)-thiolactone (Hcy-LDL) on functional properties on human endothelial cells. Hcy-thiolactone, a reactive product formed in human cells from enzymatic conversion of Hcy, was hypothesized to play an important role in Hcy-induced vascular damages. Using endothelial cultured cells [human aortic endothelial cells (HAEC)] as cellular model, we evaluated nitric oxide (NO) production, cytoplasmic Ca(2+) levels, Na(+)/K(+)-ATPase activity, and peroxynitrite production in cells incubated in the presence of control LDL or Hcy-LDL. Homocysteinylation of LDL was carried out by incubation of LDL, isolated from plasma of healthy subjects, with 100 microm Hcy-thiolactone. A significant increase in cytoplasmic Ca(2+) levels and peroxynitrite production and a decrease in Na(+)/K(+)-ATPase and NO production in HAEC incubated with Hcy-LDL compared with HAEC incubated with control LDL were observed. Moreover, a positive correlation was found between Na(+)/K(+)-ATPase activity and cytoplasmic Ca(2+) content and between peroxynitrite activity and cytoplasmic Ca(2+) content. In conclusion, our results demonstrated that LDL homocysteinylated in vitro induced alterations of functional properties and NO metabolism of human endothelial cells.
Titolo: | Modification induced by homocysteine and low-density lipoprotein on human aortic endothelial cells: an in vitro study. |
Autori: | |
Data di pubblicazione: | 2004 |
Rivista: | |
Abstract: | The aim of the present study was to investigate the effect exerted by low-density lipoprotein (LDL) modified by homocysteine (Hcy)-thiolactone (Hcy-LDL) on functional properties on human endothelial cells. Hcy-thiolactone, a reactive product formed in human cells from enzymatic conversion of Hcy, was hypothesized to play an important role in Hcy-induced vascular damages. Using endothelial cultured cells [human aortic endothelial cells (HAEC)] as cellular model, we evaluated nitric oxide (NO) production, cytoplasmic Ca(2+) levels, Na(+)/K(+)-ATPase activity, and peroxynitrite production in cells incubated in the presence of control LDL or Hcy-LDL. Homocysteinylation of LDL was carried out by incubation of LDL, isolated from plasma of healthy subjects, with 100 microm Hcy-thiolactone. A significant increase in cytoplasmic Ca(2+) levels and peroxynitrite production and a decrease in Na(+)/K(+)-ATPase and NO production in HAEC incubated with Hcy-LDL compared with HAEC incubated with control LDL were observed. Moreover, a positive correlation was found between Na(+)/K(+)-ATPase activity and cytoplasmic Ca(2+) content and between peroxynitrite activity and cytoplasmic Ca(2+) content. In conclusion, our results demonstrated that LDL homocysteinylated in vitro induced alterations of functional properties and NO metabolism of human endothelial cells. |
Handle: | http://hdl.handle.net/11566/50062 |
Appare nelle tipologie: | 1.1 Articolo in rivista |