Fig 4. Neutrophil proteins inhibit Aβ_1–42 binding to RAGE.

(a) Graph shows binding of Aβ_1–42 to RAGE when CAP37 was added simultaneously to wells at increasing concentrations in the presence (inverted triangles) or absence (squares) of protease inhibitors. An IC₅₀ value of 1.28 μM was computed for inhibition of Aβ_1–42 binding to RAGE by CAP37. Two separate Kruskal-Wallis tests were performed for Aβ_1–42 binding in the presence and absence of protease inhibitors. A Dunn’s multiple comparisons test was performed for each separate Kruskal-Wallis test to compare binding of Aβ_1–42 to RAGE in the presence of increasing concentrations of CAP37. Data are mean ± SEM of results. *p<0.05, **p<0.01. (b) Graph shows binding of Aβ_1–42 to RAGE when neutrophil elastase was added simultaneously to wells at increasing concentrations in the presence (inverted triangles) or absence (squares) of protease inhibitors. An IC₅₀ value of 4.85 nM was computed for inhibition of Aβ_1–42 binding to RAGE by neutrophil elastase in the absence of protease inhibitors. Two separate Kruskal-Wallis tests were performed for Aβ_1–42 binding in the presence and absence of protease inhibitors. A Dunn’s multiple comparisons test was performed for each separate Kruskal-Wallis test to compare binding of Aβ_1–42 to RAGE in the presence of increasing concentrations of neutrophil elastase. No inhibition occurred in the presence of protease inhibitors. Data are mean ± SEM of results. *p<0.05.