TGF-?1 Upregulates the Expression of Triggering Receptor Expressed on Myeloid Cells 1 in Murine Lungs.

ABSTRACT: Triggering receptor expressed on myeloid cells 1 (TREM-1) increases the expression of TGF-? family genes, which are known as profibrogenic cytokines in the pathogenesis of pulmonary fibrosis. In this study, we determined whether TGF-?1 regulated the expression of TREM-1 in a mouse model of pulmonary fibrosis. The expression of TGF-?1 and TREM-1 was increased on day 7, 14, and 21 after single intratracheal injection of bleomycin (BLM). And there was positive correlation between the expression of TGF-?1 and TREM-1. TGF-?1 increased expression of TREM-1 mRNA and protein in a time- and dose-dependent manner in mouse macrophages. The expression of the activator protein 1 (AP-1) was increased in lung tissues from mouse after BLM injection and in mouse macrophages after TGF-?1 treatment, respectively. TGF-?1 significantly increased the relative activity of luciferase in the cells transfected with plasmid contenting wild type-promoter of TREM-1. But TGF-?1 had no effect on the activity of luciferase in the cells transfected with a mutant-TREM1 plasmid carrying mutations in the AP-1 promoter binding site. In conclusion, we found the expression of TREM-1 was increased in lung tissues from mice with pulmonary fibrosis. TGF-?1 increased the expression of TREM-1 in mouse macrophages partly via the transcription factor AP-1.

SUBMITTER: Peng L 

PROVIDER: S-EPMC4704059 | biostudies-literature | 2016 Jan

REPOSITORIES: biostudies-literature