0000000000171093
AUTHOR
Naig Le Guern
High Plasma Concentration of Non-Esterified Polyunsaturated Fatty Acids Is a Specific Feature of Severe COVID-19 Pneumonia
Background: The pathogenesis of severe COVID-19 is frequently associated with an uncontrolled inflammatory response. Severe forms of COVID-19 appear to be more frequent in obese patients, but an association with metabolic disorders is not established. Here, we focused on lipoprotein metabolism in patients hospitalized for severe pneumonia, depending on COVID-19 status. Methods: Thirty-four non-COVID-19 and 27 COVID-19 patients with severe pneumonia were enrolled. Most of them required intensive care. Plasma lipid levels, lipoprotein metabolism, and clinical and biological features were assessed. Findings: Despite similar initial metabolic comorbidities and respiratory severity, COVID-19 pat…
α-Tocopherol Modulates Phosphatidylserine Externalization in Erythrocytes
Objective— The aim of the present study was to assess the effect of α-tocopherol, the main vitamin E isomer on phosphatidylserine (PS) exposure at the surface of circulating erythrocytes, and to determine consequences on erythrocyte properties. Methods and Results— In vitro α-tocopherol enrichment of isolated erythrocytes significantly decreased PS externalization as assessed by lower Annexin V-fluorescein isothiocyanate labeling. Plasma phospholipid transfer protein (PLTP) transfers vitamin E, and both α-and γ-tocopherol accumulated in circulating erythrocytes from PLTP-deficient homozygous (PLTP −/− ) mice as compared with wild-type mice. In agreement with in vitro studies, vitamin E–enr…
Plasma phospholipid transfer protein (PLTP) modulates adaptive immune functions through alternation of T helper cell polarization
International audience; Objective: Plasma phospholipid transfer protein (PLTP) is a key determinant of lipoprotein metabolism, and both animal and human studies converge to indicate that PLTP promotes atherogenesis and its thromboembolic complications. Moreover, it has recently been reported that PLTP modulates inflammation and immune responses. Although earlier studies from our group demonstrated that PLTP can modify macrophage activation, the implication of PLTP in the modulation of T-cell-mediated immune responses has never been investigated and was therefore addressed in the present study. Approach and results: In the present study, we demonstrated that PLTP deficiency in mice has a pro…
Innate immune response triggered by triacyl lipid A is dependent on phospholipid transfer protein (PLTP) gene expression
Hexaacyl lipopolysaccharide (LPS) aggregates in aqueous media, but its partially deacylated lipid A moiety forms monomers with weaker toxicity. Because plasma phospholipid transfer protein (PLTP) transfers hexaacyl LPS, its impact on metabolism and biological activity of triacyl lipid A in mice was addressed. Triacyl lipid A bound readily to plasma high-density lipoproteins (HDLs) when active PLTP was expressed [HDL-associated lipid A after 4.5 h: 59.1+/-16.0% of total in wild-type (WT) vs. 32.5+/-10.3% in PLTP-deficient mice, P0.05]. In the opposite to hexaacyl LPS, plasma residence time of lipid A was extended by PLTP, and proinflammatory cytokines were produced in higher amounts in WT th…
Cholesterol accumulation is increased in macrophages of phospholipid transfer protein-deficient mice: normalization by dietary alpha-tocopherol supplementation.
Objective— Phospholipid transfer protein (PLTP) is a multifunctional, extracellular lipid transport protein that plays a major role in lipoprotein metabolism and atherosclerosis. Recent in vivo studies suggested that unlike systemic PLTP, macrophage-derived PLTP would be antiatherogenic. The present study aimed at characterizing the atheroprotective properties of macrophage-derived PLTP. Methods and Results— Peritoneal macrophages were isolated from PLTP-deficient and wild-type mice and their biochemical characteristics were compared. It is shown that macrophages isolated from PLTP-deficient mice have increased basal cholesterol content and accumulate more cholesterol in the presence of LD…
Development of Abdominal Aortic Aneurysm Is Decreased in Mice with Plasma Phospholipid Transfer Protein Deficiency
International audience; Plasma phospholipid transfer protein (PLTP) increases the circulating levels of proatherogenic lipoproteins, accelerates blood coagulation, and modulates inflammation. The role of PLTP in the development of abdominal aortic aneurysm (AAA) was investigated by using either a combination of mechanical and elastase injury at one site of mouse aorta (elastase model) or continuous infusion of angiotensin II in hyperlipidemic ApoE-knockout mice (Ang II model). With the elastase model, complete PLTP deficiency was associated with a significantly lower incidence and a lesser degree of AAA expansion. With the Ang II model, findings were consistent with those in the elastase mo…