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Remodeling of the HDL proteome with treatment response to abatacept or adalimumab in the AMPLE trial of patients with rheumatoid arthritis.
Charles-Schoeman, C, Gugiu, GB, Ge, H, Shahbazian, A, Lee, YY, Wang, X, Furst, DE, Ranganath, VK, Maldonado, M, Lee, T, et al
Atherosclerosis. 2018;:107-114
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Abstract
BACKGROUND AND AIMS To evaluate changes in the high-density lipoprotein (HDL) proteome and HDL function in active rheumatoid arthritis (RA) patients initiating therapy with abatacept or adalimumab in the Abatacept Versus Adalimumab Comparison in Biologic-Naïve RA Subjects with Background Methotrexate (AMPLE) study. METHODS Ultra high-pressure liquid chromatography (UHPLC) coupled with ion mobility mass spectrometry (LC-IM-MS) was used to analyze proteins associated with immunoaffinity-captured HDL from plasma of 30 patients with RA randomized to either abatacept (n = 15) or adalimumab (n = 15) therapy. Paraoxonase 1 (PON1) activity, HDL anti-oxidant capacity, cholesterol profiles, and homocysteine levels were also measured at baseline and following treatment. Repeated-measures analyses were performed using mixed-effect linear models to model the within-subject covariance over time. RESULTS In models controlling for age, sex and treatment group, improvement in inflammation measured by decreases in CRP was associated with improvement in HDL function and changes in several HDL-associated proteins including significant decreases in lipopolysaccharide-binding protein, serum amyloid A-I (SAA-I) and inter-alpha-trypsin inhibitor heavy chain H4 (p values < 0.05). Improvement in disease activity was also associated with changes in multiple HDL-associated proteins. Adalimumab was associated with higher PON1 activity, HDL-associated serotransferrin, and HDL-associated immunoglobulin J chain, and lower HDL-associated SAA-I over time compared with abatacept. CONCLUSIONS Improvement in inflammation associated with treatment of RA, using either abatacept or adalimumab in the AMPLE study, was associated with improvement in HDL function and significant alterations in the HDL proteome, including proteins involved in the immune response, proteinase inhibition, and lipid metabolism.
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Understanding high-density lipoprotein function in disease: recent advances in proteomics unravel the complexity of its composition and biology.
Birner-Gruenberger, R, Schittmayer, M, Holzer, M, Marsche, G
Progress in lipid research. 2014;:36-46
Abstract
Although the epidemiology of high-density lipoprotein (HDL) cholesterol and cardiovascular risk has been consistent, pharmacologic interventions to increase HDL-cholesterol by delaying HDL catabolism did not translate into reduction in cardiovascular risk. HDL particles are small, protein-rich when compared to other plasma lipoprotein classes. Latest progresses in proteomics technology have dramatically increased our understanding of proteins carried by HDL. In addition to proteins with well-established functions in lipid transport, iron transport proteins, members of the complement pathway, and proteins involved in immune function and acute phase response were repeatedly identified on HDL particles. With the unraveling of the complexity of the HDL proteome, different laboratories have started to monitor its changes in various disease states. In addition, dynamic aspects of HDL subgroups are being discovered. These recent studies clearly illustrate the promise of HDL proteomics for deriving new biomarkers for disease diagnosis and to measure the effectiveness of current and future treatment regimens. This review summarizes recent advances in proteomics and lipidomics helping to understand HDL function in health and disease.
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Pro- or anti-inflammatory role of apolipoprotein A-1 in high-density lipoproteins?
Vuilleumier, N, Dayer, JM, von Eckardstein, A, Roux-Lombard, P
Swiss medical weekly. 2013;:w13781
Abstract
Apolipoprotein A-1 (apoA-1) is the principal protein fraction of high-density lipoprotein (HDL), conferring to the latter many of its pleiotropic atheroprotective functions. After its effect on cholesterol efflux, the second most studied feature of apoA-1 is its anti-inflammatory property. In addition, it interferes with lipid peroxidation and innate immune receptors. These anti-inflammatory effects are due to various properties, in particular the ability to inhibit the transendothelial migration of immune cells by reducing integrin expression, to inhibit monocyte activation and cytokine production induced by T-cell contact, to inhibit lipid peroxidation and to interfere with innate immune receptors. Recent studies have demonstrated that during chronic systemic inflammation HDL could lose some of its atheroprotective functions and become dysfunctional or even proinflammatory. Recent evidence suggests that specific post-translational modifications of apoA-1 transform this genuine anti-inflammatory molecule into a proinflammatory one. The structural changes include chlorination, nitration and carbamylation of amino acids by myeloperoxidase, oxidation by reactive carbonyls, as well as glycation. Humoral autoimmunity to apoA-1 and HDL has been reported in populations at high cardiovascular risk and constitutes another emerging mechanism contributing to the loss of functions of apoA-1 and HDL. The fact that in recent trials cholesteryl ester transfer protein inhibitors (torcerapib and dalcetrapib) have unfortunately failed to prevent cardiovascular disease despite increasing cholesterol efflux in vitro and HDL levels in vivo, further highlights the clinical importance of understanding the mechanisms driving apoA-1 and HDL towards pro- or anti-inflammatory molecules. These findings should not affect current dyslipidaemia management guidelines.
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Marked HDL deficiency and premature coronary heart disease.
Schaefer, EJ, Santos, RD, Asztalos, BF
Current opinion in lipidology. 2010;(4):289-97
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Abstract
PURPOSE OF REVIEW Our purpose is to review recent publications in the area of marked human HDL deficiency, HDL particles, coronary heart disease (CHD), amyloidosis, the immune response, and kidney disease. RECENT FINDINGS Lack of detectable plasma apolipoprotein (apo) A-I can be due to DNA deletions, rearrangements, or nonsense or frameshift mutations within the APOA1 gene resulting in a lack of apoA-I secretion. Such patients have marked HDL deficiency, normal levels of triglycerides and LDL cholesterol, and can have xanthomas and premature CHD. ApoA-I variants with amino acid substitutions, especially in the region of amino acid residues 50-93 and 170-178, have been associated with amyloidosis. Patients with homozygous Tangier disease have defective cellular cholesterol efflux due to mutations in the adenosine triphosphate-binding cassette transporter A1, detectable plasma apoA-I levels and prebeta-1 HDL in their plasma. They have decreased LDL cholesterol levels and can develop neuropathy and premature CHD. Patients with lecithin: cholesterol acyltransferase deficiency have both prebeta-1 and alpha-4 HDL present in their plasma and develop corneal opacities, anemia, proteinuria, and kidney failure. SUMMARY Patients with marked HDL deficiency can have great differences in their clinical phenotype depending on the underlying defect.