Statins prevent tissue factor induction by protease‐activated receptors 1 and 2 in human umbilical vein endothelial cells in vitro

Abstract

the inflammatory and proliferative responses triggered by tissue injury. We have previously shown that PAR1 or PAR2 occupancy by specific PAR-agonist peptides (PAR-APs) induces tissue factor (TF) expression in human umbilical vein endothelial cells (HUVECs), where TF regulation by PAR1 (but not by PAR2) requires intact endothelial caveolin-enriched membrane microdomains in which PAR1 and caveolin-1 associate. Objectives: The aim of this study was to determine the effects of cholesterol-lowering agents (statins) and cholesterol-loading lipoprotein on PAR1-AP-mediated and PAR2-AP-mediated TF induction in HUVECs. Results: Statins completely prevented TF induction by PAR-APs in an isoprenoid-independent manner, induced the delocalization of PAR1 from caveolin-enriched membrane microdomains without affecting PAR1 mRNA, and decreased PAR2 mRNA and protein levels. Statins also prevented PAR-AP-mediated extracellular signal-related kinase 1/2 activation, which is crucial for TF induction. The redistribution of PAR1 is accompanied by the relocation of the membrane microdomainassociated G-protein a, caveolin-1, and Src, which we previously showed to play a key role in signal transduction and TF induction. Conversely, cholesterol loading potently amplified PAR1-AP-induced TF, probably as a result of the increased abundance of PAR1 and the Src and G-protein a signaling molecules in the caveolin-1-enriched fraction, without affecting PAR1 mRNA. Conclusions: As PARs have important functions in hemostasis, cancer, thrombosis, and inflammatory processes, our findings that statins prevent TF induction by PAR-APs altering the membrane localization of PAR1 and the expression of PAR2 suggest that they may provide health benefits other than reducing atherosclerosis.

Weibel-Palade body size modulates the adhesive activity of its von Willebrand Factor cargo in cultured endothelial cells

“…More recently, in vitro , animal and clinical studies have provided evidence that statins have also antithrombotic effects25262728293031323334. Given our previous findings about the size of WPBs affecting platelet recruitment at the endothelial surface, and the antithrombotic phenotypes of statins, we investigated the effect on WPB size of this class of drugs.…”

Differential Membrane Dipolar Orientation Induced by Acute and Chronic Cholesterol Depletion

“…A popular approach to explore cholesterol-sensistivity of membrane proteins has been depletion of membrane cholesterol, followed by monitoring membrane protein function. As mentioned above, this can be achieved by acute 34, 35, 58–63 or chronic 36, 37, 44, 63–65 depletion of membrane cholesterol. Interestingly, the consequences of acute and chronic cholesterol depletion are often different 66–72 and this has resulted in a discussion on the molecular mechanism underlying these processes.…”

Tempol, an Intracellular Antioxidant, Inhibits Tissue Factor Expression, Attenuates Dendritic Cell Function, and Is Partially Protective in a Murine Model of Cerebral Malaria

“…Statins (e.g. rosuvastatin) prevent O 2 − production by inhibiting isoprenylation of p21 Rac (which is critical for assembly of NOX) [101] and inhibit NF-κB activation and signaling pathways in ECs [67], [102]. Furthermore, simvastatin decreases monocyte TF expression and procoagulant/inflammatory state in mice, monkeys, and humans given a hypercholesterolemic diet [103] or LPS-induced monocyte TF expression in humans [104].…”

“…Total RNA (100 ng) was used to synthesize cDNA using a qScript cDNA Supermix kit (Quanta Biosciences, Gaithersburg, MD, USA). Quantification of expression for TF and 18S were performed in a LightCycler 480 (Roche Applied Science, Indianapolis, IN, USA) using a PerfeCTa® SYBR® Green FastMix® (Quanta Biosciences) and specific primers for TF [67] or 18S housekeeping gene. Relative quantification analysis of TF versus 18S was performed using LightCycler 480 software [68].…”