Cholesterol-induced macrophage apoptosis requires ER stress pathways and engagement of the type A scavenger receptor.

Journal Article (Journal Article)

Macrophage death in advanced atherosclerosis promotes necrosis and plaque destabilization. A likely cause of macrophage death is accumulation of free cholesterol (FC) in the ER, leading to activation of the unfolded protein response (UPR) and C/EBP homologous protein (CHOP)-induced apoptosis. Here we show that p38 MAPK signaling is necessary for CHOP induction and apoptosis. Additionally, two other signaling pathways must cooperate with p38-CHOP to effect apoptosis. One involves the type A scavenger receptor (SRA). As evidence, FC loading by non-SRA mechanisms activates p38 and CHOP, but not apoptosis unless the SRA is engaged. The other pathway involves c-Jun NH2-terminal kinase (JNK)2, which is activated by cholesterol trafficking to the ER, but is independent of CHOP. Thus, FC-induced apoptosis requires cholesterol trafficking to the ER, which triggers p38-CHOP and JNK2, and engagement of the SRA. These findings have important implications for understanding how the UPR, MAPKs, and the SRA might conspire to cause macrophage death, lesional necrosis, and plaque destabilization in advanced atherosclerotic lesions.

Full Text

Duke Authors

Cited Authors

  • Devries-Seimon, T; Li, Y; Yao, PM; Stone, E; Wang, Y; Davis, RJ; Flavell, R; Tabas, I

Published Date

  • October 10, 2005

Published In

Volume / Issue

  • 171 / 1

Start / End Page

  • 61 - 73

PubMed ID

  • 16203857

Pubmed Central ID

  • PMC2171235

International Standard Serial Number (ISSN)

  • 0021-9525

Digital Object Identifier (DOI)

  • 10.1083/jcb.200502078

Language

  • eng

Conference Location

  • United States