牙龈卟啉单胞菌脂多糖刺激巨噬细胞表达髓样细胞触发受体-1的研究

ObjectiveSoluble triggering receptors ex-pressed by myeloid cells-1 (sTREM-1) and inflammatory cytokine tumor necrosis factor-α (TNF-α) in macrophage cells were stimulated byPorphyromonas gingivalis-lipopolysac-charide (Pg-LPS) to investigate the expression of triggering receptors expressed by myeloid cells-1 (TREM-1) and further explore the correlation between TREM-1 and the pathogenesis of periodontitis.MethodsTHP-1 cells (a human monocytic cell line derived from an acute monocytic leukemia patient) were induced to differentiate THP-1 macrophages by phorbol-12-myristate-13-acetate and were injected with 0 (blank control), 0.5, or 1.0 μg·mL^-1Pg-LPS. The THP-1 cells were then grouped in accordance with incubation time, and each group was incubated for 4, 6, 12, or 24 h. The expression of the TREM-1 mRNA in macrophages was detected by real-time quantitative polymerase chain reaction, while the expression of TREM-1 protein was detected by Western blot; the site where TREM-1 protein expression was observed in macrophages was detected by immunofluorescence staining, and the expression of soluble sTREM-1 and TNF-α in cell culture medium was detected by enzyme-linked immunosorbent assay.ResultsCompared with the blank control group, the expression of TREM-1 mRNA, TREM-1 protein, and sTREM-1 in Pg-LPS-stimulated macrophages was significantly upregulated (P-1Pg-LPS group than in the 0.5 μg·mL^-1group; this expression was statistically significant since the 6, 4, and 4 h time point (P-1) for 24 h, and the staining sites of TREM-1 were mainly located in the cell membrane of the macro-phages (P-1Pg-LPS stimulated groups than in 0.5 μg·mL^-1Pg-LPS-stimulated groups since the 6 h time point (P-1Pg-LPS-stimulated macrophages were positively correlated with one another (r=1,P-1Pg-LPS (r=1,PConclusionThe expression of TREM-1 mRNA, TREM-1 protein, and sTREM-1 in the culture supernatant in Pg-LPS-stimulated macrophages was significantly upregulated on the basis of the concentration of Pg-LPS; moreover, their upregulation was positively correlated with one another. The expression of TNF-α in the supernatant of cell culture was also upregulated and was positively correlated with the expression of sTREM-1 at the group of high Pg-LPS concentration (1.0 μg·mL^-1). Results reveal that TREM-1, which has been realized as a proinflammatory receptor protein, can promote the development of periodontitis by regulating the expression of TNF-α in macrophages.