Fig. 4

Distribution and proliferation markers in immune cells during the response to retinal damage. Images show staining of L-plastin (magenta), PCNA (green), and DAPI (blue) in cryosections of retinas injected with saline (A–C and G–I) or ouabain (E–F and J–L) at 24, 48, and 72 hpi. Images are from regions of peripheral retina (rows 1 and 2, A–F) or central retina (rows 3 and 4, G–L). PCNA+, L-plastin+ cells are indicated with white arrows, while PCNA+ non-immune cells are indicated with asterisks. In images of peripheral retina, regions corresponding to the ciliary marginal zone (CMZ) are within dotted ellipses. A–C and G–I Saline injection does not result in significant changes in L-plastin+ cell accumulation, location, or morphology and does not result in significant PCNA+ signal in L-plastin+ cells (A–C and G–I). D–F and J–L In ouabain-lesioned retinas, significant numbers of ameboid-shaped L-plastin+ cells are located in the region vitreal to the ganglion cell layer at 24 hpi and many are PCNA+ (D, J, arrows). At 48 hpi ouabain, L-plastin+ cells remain ameboid in shape, appear to accumulate at the region of the ouabain-induced lesion, and many are PCNA+ (E and K, arrows). By 72 hpi, PCNA+ signal is mainly localized to non-immune cells (asterisks*), although ameboid-shaped L-plastin+ cells remain in regions corresponding to the lesion (F and L). K, L Arrowheads indicate immune cells invading from regions posterior to the retina. G–L Regions denoted with dotted white lines indicate regions (corresponding to the lesion) used for quantification of L-plastin+ cells shown in Fig. 4. Scale bar in A (applies to all images) = 20 μm. ONL = outer nuclear layer, INL = inner nuclear layer, GCL = ganglion cell layer