Figure 3: Anti-DEK aptamers reduce NET formation in zymosan-injected joints.

(a) Representative confocal microscopy images of permeabilized joint sections from knees injected with zymosan and control aptamer (n=3) or anti-DEK aptamer (n=3) stained for Ly6-G (green) or the NET marker citrullinated histone H3 (cit–H3) antibody (red). Magnification × 60 (scale bar 20 μm). Staining for cit-H3 is undetectable in the neutrophils in the DTA 64-injected knees, but is readily seen in the control aptamer-injected joints. The absence of cit-H3 in the DTA-64 injected-knees correlates with the loss of NETs. (Please note that permeabilization of the cells makes it difficult to detect NET structures; please see NET staining in the non-permeabilized section with MPO in Supplementary Fig. 6E.) (b) Western blot analysis of knee joint homogenates from eight different mice (four joints/group) confirming dramatic decreases in cit-H3 in joints injected with DTA-64 as compared to control aptamer.