betadex and geranylgeranyl-pyrophosphate

Statins are HMG-CoA reductase inhibitors within the framework of cholesterol biosynthesis and used to lower the low-density lipoprotein (LDL). There are other aspects of statins can deploy a protective effect, even without the LDL's lowering. The aim of this study is to investigate the effects of different type of statins on proliferative and migrative behaviors of Hepatocyte Growth Factor (HGF) induced human umbilical vein endothelial cells (HUVECs).. Human umbilical vein endothelial cells were isolated and cultured. Groups were designed in order to observe the effects of every individual substance. HUVECs were stimulated with HGF, statins and farnesylpyrophosphat ammonium salt (FPP) or geranylgeranyl-pyrophosphate (GGPP), respectively. Cell proliferations were counted 48 hours after initial stimuli and distances between migration fronts were used in migration analyses.. All types of statins showed significant anti-migrative and anti-proliferative characters. Simvastatin and fluvastatin but not cerivastatin, were able to inhibit the HGF-depending migration and showed a significant effect on the inhibition of the isoprenylation (GGPP). Only simvastatin influenced the HGF-depending migration via inhibiting the isoprenylation process through GGPP. Cerivastatin significantly decreased the proliferation and Fluvastatin significantly enhanced the migration behaviors of HUVECs when they were co-incubated with methyl-8-cyclodextrin (MCD).. Statins countermand the proproliferative and as well as the promigrative effect of HGF on HUVECs. The mechanisms which provoke this effect are dependent on the type of statin. Direct interactions of statins with lipid rafts play a significant role in the endothelial cell mechanisms.

Topics: beta-Cyclodextrins; Cell Movement; Cell Proliferation; Fatty Acids, Monounsaturated; Fluvastatin; Hepatocyte Growth Factor; Human Umbilical Vein Endothelial Cells; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Indoles; Membrane Microdomains; Polyisoprenyl Phosphates; Pyridines; Sesquiterpenes; Simvastatin

Extracellular adenosine production by the GPI-anchored Ecto-5'-Nucleotidase (Ecto-5'-Nu) plays an important role in the cardiovascular system, notably in defense against hypoxia. It has been previously suggested that HMG-CoA reductase inhibitors (HRIs) could potentiate the hypoxic stimulation of Ecto-5'Nu in myocardial ischemia. In order to elucidate the mechanism of Ecto-5'-Nu stimulation by HRIs, Ecto-5'-Nu activity and expression were determined in an aortic endothelial cell line (SVAREC) incubated with lovastatin. Lovastatin enhanced Ecto-5'-Nu activity in a dose-dependent manner. This increase was not supported by de novo synthesis of the enzyme because neither the mRNA content nor the total amount of the protein were modified by lovastatin. By contrast, lovastatin enhanced cell surface expression of Ecto-5'-Nu and decreased endocytosis of Ecto-5'-Nu, as evidenced by immunostaining. This effect appeared unrelated to modifications of cholesterol content or Ecto-5'-Nu association with detergent-resistant membranes. The effect of lovastatin was reversed by mevalonate, the substrate of HMG-CoA reductase, by its isoprenoid derivative, geranyl-geranyl pyrophosphate, and by cytotoxic necrotizing factor, an activator of Rho-GTPases. Stimulation of Ecto-5'-Nu by lovastatin enhanced the inhibition of platelet aggregation induced by endothelial cells. In conclusion, lovastatin enhances Ecto-5'-Nu activity and membrane expression in endothelial cells. This effect seems independent of lowering cholesterol content but could be supported by an inhibition of Ecto-5'-Nu endocytosis through a decrease of Rho-GTPases isoprenylation.

Topics: 5'-Nucleotidase; Animals; beta-Cyclodextrins; Cell Hypoxia; Cell Membrane; Cells, Cultured; Cholesterol; Cyclodextrins; Dose-Response Relationship, Drug; Endocytosis; Endothelium, Vascular; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Lovastatin; Mevalonic Acid; Platelet Aggregation; Polyisoprenyl Phosphates; Protein Prenylation; Rats; rho GTP-Binding Proteins; RNA, Messenger