Regular Research Articles
Identification and characterization of LPLAT7 as an sn-1-specific lysophospholipid acyltransferase
The main fatty acids at the sn-1 position of phospholipids (PLs) are saturated or monounsaturated fatty acids such as palmitic acid (C16:0), stearic acid (C18:0), and oleic acid (C18:1) and are constantly replaced, like unsaturated fatty acids at the sn-2 position. However, little is known about the molecular mechanism underlying the replacement of fatty acids at the sn-1 position, i.e., the sn-1 remodeling. Previously, we established a method to evaluate the incorporation of fatty acids into the sn-1 position of lysophospholipids (lyso-PLs).Plasma FA composition in familial LCAT deficiency indicates SOAT2-derived cholesteryl ester formation in humans
Mutations in the LCAT gene cause familial LCAT deficiency (Online Mendelian Inheritance in Man ID: #245900), a very rare metabolic disorder. LCAT is the only enzyme able to esterify cholesterol in plasma, whereas sterol O-acyltransferases 1 and 2 are the enzymes esterifying cellular cholesterol in cells. Despite the complete lack of LCAT activity, patients with familial LCAT deficiency exhibit circulating cholesteryl esters (CEs) in apoB-containing lipoproteins. To analyze the origin of these CEs, we investigated 24 carriers of LCAT deficiency in this observational study.The SARS-CoV2 envelope differs from host cells, exposes procoagulant lipids, and is disrupted in vivo by oral rinses
The lipid envelope of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is an essential component of the virus; however, its molecular composition is undetermined. Addressing this knowledge gap could support the design of antiviral agents as well as further our understanding of viral-host protein interactions, infectivity, pathogenicity, and innate immune system clearance. Lipidomics revealed that the virus envelope comprised mainly phospholipids (PLs), with some cholesterol and sphingolipids, and with cholesterol/phospholipid ratio similar to lysosomes.An anti-ANGPTL3/8 antibody decreases circulating triglycerides by binding to a LPL-inhibitory leucine zipper-like motif
Triglycerides (TG) are required for fatty acid transport and storage and are essential for human health. Angiopoietin-like-protein 8 (ANGPTL8) has previously been shown to form a complex with ANGPTL3 that increases circulating TG by potently inhibiting LPL. We also recently showed that the TG-lowering apolipoprotein A5 (ApoA5) decreases TG levels by suppressing ANGPTL3/8-mediated LPL inhibition. To understand how LPL binds ANGPTL3/8 and ApoA5 blocks this interaction, we used hydrogen-deuterium exchange mass-spectrometry and molecular modeling to map binding sites of LPL and ApoA5 on ANGPTL3/8.Apolipoprotein F concentration, activity, and the properties of LDL controlling ApoF activation in hyperlipidemic plasma
Apolipoprotein F (ApoF) modulates lipoprotein metabolism by selectively inhibiting cholesteryl ester transfer protein activity on LDL. This ApoF activity requires that it is bound to LDL. How hyperlipidemia alters total plasma ApoF and its binding to LDL are poorly understood. In this study, total plasma ApoF and LDL-bound ApoF were quantified by ELISA (n = 200). Plasma ApoF was increased 31% in hypercholesterolemic plasma but decreased 20% in hypertriglyceridemia. However, in donors with combined hypercholesterolemia and hypertriglyceridemia, the elevated triglyceride ameliorated the rise in ApoF caused by hypercholesterolemia alone.
