Validation of the Circulating Monocyte Being Representative of the Cholesterol-Loaded Macrophage: Biomediator Activity

2008 ◽  
Vol 132 (9) ◽  
pp. 1432-1435
Author(s):  
Sridevi Devaraj ◽  
Ishwarlal Jialal
Keyword(s):  
Peripheral Blood ◽  
Superoxide Anion ◽  
Interleukin 1 ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Surface Expression ◽  
Blood Monocytes ◽  
Peripheral Blood Monocytes ◽  
Macrophage Activity ◽  
Human Endothelium

Abstract Context.—Inflammation is pivotal to atherosclerosis. The monocyte-macrophage, a crucial cell in atherogenesis, is present during all stages of atherosclerosis. However, there is a paucity of data comparing circulating monocytes to cholesterol-laden macrophages (foam cells), with regard to their atherogenic properties, especially in subjects with established risk factors such as hyperlipidemia. Objective.—To determine whether the circulating blood monocyte is representative of the cholesterol-loaded macrophage with regard to its proatherogenicity in healthy controls and hyperlipidemic patients. Design.—Fasting blood was drawn from 32 subjects (n = 16 controls and n = 16 hyperlipidemic patients), and peripheral blood monocytes were obtained. Also, macrophages were cultured and loaded with acetyl low-density lipoprotein on day 10. Day 1 peripheral blood monocytes and day 11 cholesterol-loaded macrophages were assessed for release of superoxide anion and cytokines (interleukin 1, interleukin 6, tumor necrosis factor α); surface expression of CD11b, VLA-4, and CD40; and adhesion to human endothelium. Results.—Monocyte and cholesterol-loaded macrophage superoxide anion release, cytokines, and adhesion of monocytes to human endothelium were significantly increased in hyperlipidemic patients compared with controls. Furthermore, following cholesterol loading, there were no significant differences in monocyte versus cholesterol-loaded macrophage activity (P = .71). Also, CD14 and CD11b surface expression on monocytes was significantly increased in hyperlipidemic patients as compared with controls. The magnitude of change in the monocytes versus cholesterol-loaded macrophages was similar. Conclusions.—From these studies, we can conclude that the monocyte, which is readily accessible, is an appropriate cell to study for modulation of proatherogenic activity, especially with regard to genomic and proteomic analyses/ microarrays.

scholarly journals Differential endocytosis of tissue plasminogen activator by serpins PAI-1 and PAI-2 on human peripheral blood monocytes

2010 ◽  
Vol 104 (12) ◽  
pp. 1133-1142 ◽  
Author(s):  
Jodi A. Lee ◽  
David R. Croucher ◽  
Marie Ranson
Keyword(s):  
Peripheral Blood ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Low Density ◽  
Lipoprotein Receptor ◽  
Blood Monocytes ◽  
Low Density Lipoprotein Receptor ◽  
Peripheral Blood Monocytes ◽  
Density Lipoprotein Receptor ◽  
Pai 1

SummaryGeneration of the broad spectrum protease plasmin is facilitated by the tissue (t-PA) and urokinase (u-PA) plasminogen activators, within multiple physiological and disease states. Finely tuned control of this proteolytic cascade is exerted by the plasminogen activator inhibitors type-1 (PAI-1/SERPINE1) and 2 (PAI-2/SERPINB2). Expression of this network of activators and inhibitors by cells of myeloid lineage appears to be highly interchangeable between physiological environments, and whilst the role of PAI-1 and PAI-2 in regulating u-PA-dependent functions is well established, the interaction between t-PA and PAI-2 on these cell types is poorly characterised. To this end, we used freshly isolated peripheral blood monocytes (PBM) as a model of a t-PA-dependent cellular environment. We demonstrate that while both PAI-1 and PAI-2 could inhibit surface-bound t-PA and are internalised predominately via low-density-lipoprotein receptor family members, PAI-1 enhanced the endocytosis of t-PA, whereas PAI-2 did not. Surface plasmon resonance analyses revealed differential binding affinities between the very-low-density-lipoprotein receptor and t-PA and t-PA:PAI-1 complexes in addition to those previously described with low-density-lipoprotein receptor-related protein. Moreover, t-PA:PAI-2 bound to both endocytosis receptors with similar kinetics to t-PA. These differential biochemical interactions between t-PA and the t-PA:PAI complexes may underlie the observed differences in endocytosis mechanisms on the PBMs. This suggests that while PAI-1 and PAI-2 function similarly in the control of cellular plasmin generation by t-PA, they may have disparate effects on the alternative functions of t-PA via modulation of its engagement with endocytosis receptors.

Is the Success of Cefazolin plus Ertapenem in Methicillin-Susceptible Staphylococcus aureus Bacteremia Based on Release of Interleukin 1-beta?

2022 ◽  
Author(s):  
Dan Smelter ◽  
Mary Hayney ◽  
George Sakoulas ◽  
Warren Rose
Keyword(s):  
Staphylococcus Aureus ◽  
Peripheral Blood ◽  
Interleukin 1 ◽  
Interleukin 1 Beta ◽  
Blood Monocytes ◽  
Salvage Regimen ◽  
Peripheral Blood Monocytes ◽  
Staphylococcus Aureus Bacteremia

Cefazolin and ertapenem has been shown to be an effective salvage regimen for refractory methicillin-susceptible Staphylococcus aureus bacteremia. Our findings suggest cefazolin plus ertapenem in vitro stimulates interleukin-1β release from peripheral blood monocytes both with and without S. aureus presence. This IL-1β augmentation was primarily driven by ertapenem. These findings support further exploration of cefazolin plus ertapenem in MSSA bacteremia and may partially explain its marked potency in vivo despite modest synergy in vitro .

Sign in / Sign up

Export Citation Format

Share Document