Format

Send to

Choose Destination
See comment in PubMed Commons below
J Biomed Res. 2014 May;28(3):213-21. doi: 10.7555/JBR.28.20130105. Epub 2013 Dec 12.

Class A scavenger receptor activation inhibits endoplasmic reticulum stress-induced autophagy in macrophage.

Author information

1
Atherosclerosis Research Centre, Laboratory of Molecular Intervention for Cardiovascular Diseases, Nanjing Medical University, Nanjing, Jiangsu 210029, China;
2
Atherosclerosis Research Centre, Laboratory of Molecular Intervention for Cardiovascular Diseases, Nanjing Medical University, Nanjing, Jiangsu 210029, China; ; State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing, Jiangsu 210029, China.
3
State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing, Jiangsu 210029, China.

Abstract

Macrophage death in advanced atherosclerosis promotes plaque necrosis and destabilization. Involvement of autophagy in bulk degradation of cellular components has been recognized recently as an important mechanism for cell survival under endoplasmic reticulum (ER) stress. We previously found that the engagement of class A scavenger receptor (SR-A) triggered JNK-dependent apoptosis in ER-stressed macrophages. However, pro-apoptotic mechanisms mediated by SR-A are not fully understood. Therefore, we sought to see if SR-A mediated apoptosis was associated with autophagy in macrophages. Here, we showed that fucoidan inhibited microtubule-associated protein light chain 3-phospholipid conjugates (LC3-II) formation as well as the number of autophagosomes under ER stress. The inhibition of LC3-II formation was paralleled by the activation of the mTOR pathway, and the inhibition of mTOR allowed LC3-II induction in macrophages treated with thapsigargin plus fucoidan. Furthermore, apoptosis induced by fucoidan was prevented under ER stress by the mTOR inhibitor. We propose that fucoidan, a SR-A agonist, may contribute to macrophage apoptosis during ER stress by inhibiting autophagy.

KEYWORDS:

ER stress; SR-A; apoptosis; autophagy; macrophage

PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Journal of Biomedical Research Icon for PubMed Central
    Loading ...
    Support Center