Chinese Journal Of Clinical Anatomy ›› 2018, Vol. 36 ›› Issue (6): 642-647.doi: 10.13418/j.issn.1001-165x.2018.06.009

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Triggering receptor expressed on myeloid cells-1 inhibits autophagy of macrophages under LPS stress

ZHU Ai-ping1, LIANG Dao-miao2, SU Qing1, LI Li-fang2, JIA Zhe2, HE Li-ping1, REN Xiang1, SUN Guo-ying 1, 3   

  1. 1. Department of Basic Medicine, College of Medine, Hunan Normal University, Changsha 410013, China; 2. Department of Clinical Medicine, College of Shu Da, Hunan Normal University, Changsha 410013, China; 3. School of Basic Medical, Central South University, Changsha 410078, China
  • Received:2018-06-26 Online:2018-11-25 Published:2018-12-29

Abstract:

Objective To observe the effect of TREM-1 on the expression of autophagy related genes in macrophages.   Methods The expression of TREM-1 protein in macrophages exposed to lipopolysaccharide (LPS) was observed. TREM-1 agonists (MAB1187) and TREM-1 antagonists (LR12) were used to regulate the activities of macrophage. qPCR was used to detect macrophage autophagy related protein ATG7, ATG5, ATG12, and microtubule associated protein 1 light chain 3 (LC3) mRNA, respectively. Expression of TREM-1, LC3 II/I, and ATG7 protein were detected by Western Blot. The expression of autophagy marker protein LC3 in macrophages under LPS stress and TREM-1 activation was detected by immunofluorescence. Results The expression of TREM-1 protein in macrophages was significantly increased under the stress of LPS (400 ng/mL, 1000 ng/mL), and the TREM-1 protein expression in macrophages reached a peak when LPS (1000 ng/mL) acted as macrophage 24 h. ATG7, ATG5, ATG12 and LC3 mRNA expression of macrophage were reduced by LPS stress. When TREM-1 antagonists were given, the expression of ATG7, ATG5, ATG12 and LC3 mRNA increased, and the autophagic gene expression of macrophage was reversed after the use of TREM-1 activator. Western Blot assay showed that TREM-1 inhibited the expression of LC3 II/I and ATG7 proteins in macrophages under LPS stress. Immunofluorescence assay showed that TREM-1 could reduce the content of LC3 protein in macrophages.  Conclusions The macrophage autophagy is inhibited after the activation of TREM-1 on the membrane of macrophage, suggesting that the TREM-1 of macrophage under LPS stress may play an inflammatory magnification by inhibiting the normal autophagy of macrophages.

Key words:  , TREM-1,  Macrophage,  LPS,  Autophagy