大鼠肠巨噬细胞TREM-1表达对其侵袭力和肠上皮细胞增殖的影响

Effect of TREM-1 expression in intestinal macrophages on their invasion and proliferation of intestinal epithelial cells

目的:探讨肠巨噬细胞髓系细胞触发受体-l(triggering receptor expressed on myeloid cells-1,TREM-1)的表达对肠巨噬细胞侵袭力和肠上皮细胞增殖的影响,进一步明确肠巨噬细胞在肠屏障功能障碍(intestinal barrier dysfunction,IBD)中可能的作用.方法:体外培养肠巨噬细胞及肠上皮细胞,逆转录-多聚酶链反应(reverse transcription-polymerase chain reaction,RT-PCR)检测大鼠肠巨噬细胞的TREM-1和肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)基因表达水平,用Tanswell板将二者共培养,MTT法绘制肠上皮细胞生长曲线,Matrigel侵袭实验检测肠巨噬细胞对肠上皮细胞的侵袭力.结果:脂多糖(lipopolysaccharide,LPS)组TREM-1及TNF-α的基因表达水平高于LPS+LP17组和空白对照(Control)组(均P<0.05);LPS+LP17组与Control组相比无差异.与Control组相比,两实验组的肠上皮细胞的生长均受到抑制(均P<0.05);LPS组肠上皮细胞生长的抑制大于LPS+LP17组(P<0.05).侵袭实验中3组平均穿膜细胞数分别为29.3±2.1、46.0±3.6和34.7±3.1.LPS组与Control组比较差异具有明显统计学意义(P<0.01),LPS组与LPS+LP17组相比差异具有统计学意义(P<0.05).结论:LP17不但能抑制肠巨噬细胞TREM-1的表达及炎症介质的释放,还可以抑制肠巨噬细胞对上皮细胞的侵袭.利用LP17阻断TREM-1信号转导可减轻肠巨噬细胞对肠上皮细胞的损害,有望成为治疗IBD的新靶点.

AIM： To explore the effect in intestinal macrophages of TREM-1 expression on their invasion and proliferation of intestinal epithelial cells to clari- fy the possible role of intestinal macrophages in the pathogenesis of intestinal barrier dysfunction （IBD）. METHODS： The expression levels of TREM-1 and TNF-α mRNAs in intestinal macrophages were determined by real-time PCR （RT-PCR） in vitro. After intestinal macrophages were co-cultured with intestinal epithelial cells in Transwell chamber, the growth curve of intestinal epithelial cells was determined by MTT assay. The matrigel invasion assay was used to detect the invasion of intestinal macrophages. RESULTS： The expression levels of TREM-1 and TNF-α in the LPS group were significantly increased compared with the control group and LPS ＋ LP17 group （both P 〈 0.05）, but showed no significant difference between the control group and LPS ＋ LP17 group （P 〉 0.05）. Compared to the control group, the growth of intestinal epithelial cells was inhibited in the LPS group and LPS ＋ LP17 group （both P 〈 0.05）, and the inhibitory effect was more significant in the LPS group （P 〈 0.01）. The average numbers of invading cells in the three groups were 29.3 ± 2.1, 46.0 ± 3.6, and 34.7 ± 3.1, respectively. There was a statistically significant difference in the average number of invading cells between the LPS ＋ LP17 group and LPS group （P 〈 0.05）. CONCLUSION： The expression of TREM-1 was inhibited by LP17 in intestinal macrophages, and TREM-1 expression inhibited the invasion of intestinal macrophages to intestinal epithelial cells. TREM-1 may be a new target for treatment of IBD.