Fig. 9.

α-1-antitrypsin enriched HDL prevents elastase induced TNF-α production by macrophages. A, J774 mouse macrophages treated with increasing amounts of porcine pancreatic elastase (PPE) or heat inactivated elastase for 4 h, TNF-α in the culture media was measured by ELISA. B, J774 cells pretreated with PBS, isolated human HDL (nHDL), the same HDL enriched with α-1-antitrypsin (A1AT nHDL), or lipid free A1AT for 1 h prior to PPE addition. C, The ability of each of the cell treatments to inhibit elastase activity was measured in a cell-free assay. D, Treatments were pre-incubated with PPE prior to addition to cells and TNF- α was measured in the culture media after 4 h. E, J774 cells were pre-incubated with each treatment for 1 h; cells were then washed twice with PBS and placed in fresh media containing PPE and TNF- α was measured in the culture media after 4 h. All experiments were repeated at least 3 times and were done in triplicates. Treatments were compared using one-way ANOVA and Tukey's multiple comparisons test, p < 0.05 was considered significant. The letters above each treatment indicate statistical significance; within each graph, bars bearing different letters were statistically different from each other.