Endothelial lipase is associated with inflammation in humans

Abstract

The aim of this study was to investigate the extent to which inflammation is linked with plasma endothelial lipase (EL) concentrations among healthy sedentary men. Plasma C-reactive protein (CRP) concentrations were measured with a highly sensitive commercial immunoassay, plasma interleukin-6 (IL-6) concentrations were measured using a commercial ELISA, and plasma secretory phospholipase A 2 type IIA (sPLA 2 -IIA) concentrations were measured using a commercial assay in a sample of 74 moderately obese men (mean body mass index, 29.8 6 5.2 kg/m 2 ). Plasma EL concentrations were positively correlated with various indices of obesity, fasting plasma insulin, and plasma CRP, IL-6, and sPLA 2 -IIA concentrations. Multiple regression analyses revealed that plasma CRP concentrations explained 14.5% (P 5 0.0008) of the variance in EL concentrations. When entered into the model, LPL activity accounted for 16.1% (P , 0.0001) and plasma CRP concentrations accounted for 20.9% (P , 0.0001) of the variance in EL concentrations. The combined impact of visceral adipose tissue (VAT) and of an inflammation score on EL concentrations was investigated. Among subjects with high or low VAT, those having a high inflammation score based on plasma CRP, IL-6, and sPLA 2 -IIA concentrations had increased plasma EL concentrations (P 5 0.0005).In conclusion, our data reveal a strong association between proinflammatory cytokines and plasma EL concentrations among healthy people with low or high VAT levels.-

ELISA System for Human Endothelial Lipase

“…It has been reported that EL expression is highly regulated by a variety of factors including inflammatory cytokines, biomechanical forces, lipopolysaccharide, angiotensin II, and oxidized LDL (29 -31 ). In fact, plasma EL mass was increased in experimental endotoxemia in humans and correlated with inflammatory markers such as C-reactive protein, interleukin-6, and secretory phospholipase A2-IIa (32,33 ). In contrast, statins reduce EL expression and plasma EL mass (16,34 ), which is accompanied by increased plasma HDL-C concentrations in humans (16 ).…”

Lipasa endotelial y su relación con la enfermedad cardiovascular y diabetes mellitus tipo 2

“…En este estudio se observó una correlación positiva entre la cantidad de grasa visceral y los niveles de LE, probablemente, secundario a otras alteraciones metabólicas asociadas a esta condición 48 . Finalmente, se ha demostrado que en humanos existe una correlación directa entre marcadores proinfl amatorios (PCRus, IL-6, entre otros) y concentraciones plasmáticas de LE, lo que apoya la hipótesis de que la enzima se encuentra sobre regulada en condiciones de infl amación 49,50 .…”

Mechanisms of lipase maturation

“…These studies suggest both pro-and antiatherogenic properties of HL, and indicate complex, contextdependent involvement of HL in cardiovascular disease [13]. EL is also emerging as an important factor in the control of lipoprotein metabolism and inflammation in humans [23,24,[68][69][70]. EL has recently been identified as an important determinant of plasma HDL-C levels [40][41][42][43], reflecting its primary role in HDL catabolism.…”

“…In addition, HL and EL have important roles in HDL remodeling and uptake that are essential to the process of reverse cholesterol transport [11,14]. Indeed, all the lipases emerge as important genetic determinants of circulating lipid levels in human populations and are thought to contribute to a number of pathogenic states including atherosclerosis and inflammation, obesity and insulin secretion and sensitivity (discussed later) [11,[21][22][23][24][25][26][27]. However, regardless of the role, lipases can function only when secreted, a process that first requires their maturation in the endoplasmic reticulum (ER).…”