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. Author manuscript; available in PMC: 2018 Jan 1.
Published in final edited form as: Arthritis Rheumatol. 2017 Jan;69(1):46–57. doi: 10.1002/art.39833

Figure 1.

Figure 1

HDL is a particle composed of multiple associated proteins, which perform its anti-inflammatory and anti-atherogenic functions. A normal, anti-inflammatory HDL particle with several of its major associated proteins including paraoxonase 1(PON1), apolipoprotein A-I (apoA-I), lecithin cholesterol acyl transferase (LCAT), and platelet activating factor acetylhydrolase (PAF-AH) is shown. In the setting of active inflammation, HDL may become non-protective, and even pro-inflammatory, by alteration in the level and function of several proteins. Protein changes shown include 1) Displacement of ApoA-I by serum amyloid A (SAA), 2) Increased haptoglobin (Hp) in HDL which binds apoA-I, blocking LCAT activation, and 3) Decreased PON1 activity via oxidative modification of PON1 by the enzyme myeloperoxidase (MPO).