Rosenbaum, A. I. | Search bioRxiv

bioRxiv2024

Inhibition of Endothelial Lipase by MEDI5884 Normalizes Phosphatidylinositol Levels in Coronary Artery Disease Patients

BackgroundEndothelial lipase (EL) promotes high-density lipoproteins (HDL) phospholipid degradation, increases catabolism of HDL and is an attractive target for the potential treatment for cardiovascular disease. Inhibition of EL using a monoclonal neutralizing antibody, MEDI5884, demonstrated increased quantity and function of HDL. Determinants of anti-atherosclerotic function of HDL comprise the interplay of various components of HDL structure-activity relationship: size, shape and composition (lipid and protein). Previous studies have shown that single doses of MEDI5884 administered to healthy nonhuman primates (NHPs) and healthy subjects resulted in a dose- dependent increase in plasma phospholipids (PL) and that plasma PI levels in placebo treated healthy subjects are significantly increased relative to CAD subjects participating in clinical trials NCT03001297 and NCT03351738, respectively. MethodsHerein, we characterized using LC-MS/MS the plasma lipidome of NHPs, heathy subjects and subjects with coronary artery disease (CAD) following MEDI5884 administration. ResultsMEDI5884 treated NHPs resulted in a prominent increase in phosphatidylinositols (PI) and cholesteryl esters (CE). Treatment with MEDI5884 restores near-normal levels of PI in CAD patients. PI increases in both healthy subjects and CAD patients were dose-dependent, correlated with exposure and saturated at approximately 200 mg MEDI5884 subcutaneous (SC) dose in CAD patients. Comparison of pharmacodynamic (PD) effects of repeat SC 200 mg doses of MEDI5884 in CAD patients revealed greater and more rapid increases in PI levels compared to HDL-C and HDL phospholipid (HDL-PL). The increase in PI species was inversely correlated with decreases in free EL mass levels. ConclusionsPI has previously been shown to possess anti-atherosclerotic properties and led to increases in HDL cholesterol (HDL-C) and reverse cholesterol transport (RCT). The mechanism by which CE levels increase as the result of MEDI5884 administration can be attributed to the observed increase in both substrates of the lecithin-cholesterol acyltransferase (LCAT) reaction: phosphatidylcholine/phosphatidylethanolamine (PC/PE) and cholesterol as the consequence of EL inhibition. Further characterization of the underlying biological mechanisms responsible for the decrease of the PI biomarker in CAD patient population relative to healthy subjects as well as in conjunction with pharmacological intervention by MEDI5884 may reveal more information on this clinically-relevant biomarker and potential role in CAD.

pharmacology and toxicology↗

bioRxiv2022

Robust and High-Throughput Analytical Flow Proteomics Analysis of Cynomolgus Monkey and Human Matrices with Zeno SWATH Data Independent Acquisition

Modern mass spectrometers routinely allow deep proteome coverage in a single experiment. These methods are typically operated at nano and micro flow regimes, but they often lack throughput and chromatographic robustness, which is critical for large-scale studies. In this context, we have developed, optimized and benchmarked LC-MS methods combining the robustness and throughput of analytical flow chromatography with the added sensitivity provided by the Zeno trap across a wide range of cynomolgus monkey and human matrices of interest for toxicological studies and clinical biomarker discovery. SWATH data independent acquisition (DIA) experiments with Zeno trap activated (Zeno SWATH DIA) provided a clear advantage over conventional SWATH DIA in all sample types tested with improved sensitivity, quantitative robustness and signal linearity as well as increased protein coverage by up to 9-fold. Using a 10-min gradient chromatography, up to 3,300 proteins were identified in tissues at 2 {micro}g peptide load. Importantly, the performance gains with Zeno SWATH translated into better biological pathway representation and improved the ability to identify dysregulated proteins and pathways associated with two metabolic diseases in human plasma. Finally, we demonstrate that this method is highly stable over time with the acquisition of reliable data over the injection of 1,000+ samples (14.2 days of uninterrupted acquisition) without the need for human intervention or normalization. Altogether, Zeno SWATH DIA methodology allows fast, sensitive and robust proteomic workflows using analytical flow and is amenable to large-scale studies. This work provides detailed method performance assessment on a variety of relevant biological matrices and serves as a valuable resource for the proteomics community.

biochemistry↗