Allograft inflammatory factor-1 (AIF-1) is crucial for the survival and pro-inflammatory activity of macrophages

ZF Yang, DW Ho, CK Lau, CT Lam… - International …, 2005 - academic.oup.com
ZF Yang, DW Ho, CK Lau, CT Lam, CT Lum, RTP Poon, ST Fan
International immunology, 2005academic.oup.com
Our previous studies revealed that macrophages played an important role in linking injury,
inflammatory and immune response in small-for-size liver transplantation. However, the
molecular basis that promoted macrophage activation was not clear. In the present study, we
explored the potential role of allograft inflammatory factor-1 (AIF-1) in mediating the survival
and pro-inflammatory activity of macrophages in a macrophage cell line. First, the
expression of AIF-1 was investigated with the stimulation of pro-inflammatory cytokines and …
Abstract
Our previous studies revealed that macrophages played an important role in linking injury, inflammatory and immune response in small-for-size liver transplantation. However, the molecular basis that promoted macrophage activation was not clear. In the present study, we explored the potential role of allograft inflammatory factor-1 (AIF-1) in mediating the survival and pro-inflammatory activity of macrophages in a macrophage cell line. First, the expression of AIF-1 was investigated with the stimulation of pro-inflammatory cytokines and anti-inflammatory treatment. Second, the level of inducible nitric oxide synthase (iNOS) and the survival and migration activity of macrophages were determined with the alterations of AIF-1 expression. Finally, a potential molecule that regulated AIF-1 expression was identified by the proteomic approach. The macrophage cell line expressed a certain level of endogenous AIF-1, which could be enhanced by pro-inflammatory cytokines IL-1β or tumor necrosis factor-α and suppressed by anti-inflammatory drug sodium salicylate. AIF-1 augmentation induced by AIF-1/PCDNA3.1(+) transfection enhanced the levels of iNOS and monocyte chemoattractant protein-1, and promoted the cell migration. On the other hand, suppression of AIF-1 expression by AIF-1/short interference RNA (siRNA) inhibited iNOS production, induced macrophage cell apoptosis and blocked the cell migration. Using two-dimensional electrophoresis, a disintegrin and metalloproteinase domain 3 (ADAM3) was identified after AIF-1/siRNA transfection. Transfection of ADAM3/PCDNA3.1(+) up-regulated the expression of AIF-1 and iNOS, whereas suppression of ADAM3 expression down-regulated AIF-1 and iNOS expression. In conclusion, AIF-1 played an important role in the survival and pro-inflammatory activity of macrophages, and ADAM3 might be an upstream molecule that regulated AIF-1 expression.
Oxford University Press