High-density lipoprotein and the acute phase responseJahangiri, AnisaCurrent Opinion in Endocrinology, Diabetes and Obesity: April 2010 - Volume 17 - Issue 2 - p 156–160 doi: 10.1097/MED.0b013e328337278b Lipids: Edited by Annabelle Rodriguez Abstract Author Information Purpose of review Inflammation and the concomitant acute phase response induce marked changes in the lipoprotein profile, particularly the high-density lipoprotein (HDL) fraction. The present review describes the transfer proteins and lipases that remodel HDL and regulate its plasma levels, discusses the changes occurring in their activities during inflammation, and the influence of this altered remodeling on HDL function. The review will also discuss the contribution of the ATP-binding-membrane-cassette transporters to the protective actions of HDL. Recent findings Studies using different models showed that remodeling of acute phase HDL in vitro generates pre-β migrating particles capable of cholesterol efflux. Induction of the acute phase response in humans resulted in a reduction of HDL phospholipids without a change in HDL-cholesterol. However, the capacity of HDL to promote cholesterol efflux ex vivo was impaired. Studies with ATP-binding-membrane-cassette transporter A1 and ATP-binding-membrane-cassette transporter G1 knockout mice demonstrated anti-inflammatory roles for these transporters by virtue of reducing cell-membrane-free cholesterol and lipid raft content, thus attenuating proinflammatory signaling pathways. Summary It is well known that HDL has anti-inflammatory properties that are diminished during inflammation. Acute phase HDL contains serum amyloid A that can be liberated during remodeling by cholesteryl ester transfer protein and secretory phospholipase A2, or other inflammatory factors. The ability of serum amyloid A and apolipoprotein A-I to promote cholesterol efflux may confer protective effects during the acute phase response. Division of Endocrinology, Department of Internal Medicine, University of Kentucky, Lexington, Kentucky, USA Correspondence to Dr Anisa Jahangiri, Division of Endocrinology, Department of Internal Medicine, University of Kentucky, Rm 533, C.T. Wethington Building, 900 South Limestone St, Lexington, KY 40536, USA Tel: +1 859 323 4933 x81383; fax: +1 859 257 3646; e-mail: email@example.com © 2010 Lippincott Williams & Wilkins, Inc.