Figure 4
Elevated expression of macrophage/microglia markers in Akimba mouse. Double immunostaining of Iba-1 (A–D) with OX-42 (E–H), and CD14 (M–P) with F4/80 (Q–T). Iba-1 staining (arrowheads) in WT (A) mice showed resident microglial cells with normal ramified morphology in the inner retina. Akita (C) mice showed minimal activation of microglia, however, had displaced microglia in the outer nuclear layer (ONL). Iba-1+ cells were both increased and amoeboid shaped in the outer retina of Kimba (B), and maximal activation was seen in Akimba (D) retina. OX-42 (block arrowheads) stains a cell surface antigen expressed by microglia, hence co-localized (arrows) with Iba-1+ microglia in WT (I). Majority of Iba-1+ microglia in Kimba (J), Akita (K) and Akimba (L) mice retina also stained positive for OX-42 (arrows). CD14 (arrowheads) is expressed by perivascular macrophages, which were minimal and located only around the vessels in the ganglion cell layer of the WT (M) mice. Increased expression was seen in the Kimba (N) and Akita (O) mice, and was drastically elevated in the outer retina of Akimba (P) mice, indicating migratory perivascular cells around new vessel sprouting from choroid into photoreceptor (PhR) region. F4/80 (block arrowheads) staining for macrophage showed predominant localization in the inner retina of the WT (Q) mice, which increased in Kimba (R) and Akita (S) mice, and was significantly elevated in GCL and ONL of Akimba (T) mice. While naïve CD14+ cell was not positive for F4/80 in WT mice (U, asterisk), co-localization (arrows) was seen in the GCL of Akita (W) mice, and in ONL/PhR of the Kimba (V) and Akimba (X) mice retina where sprouting vessels were located. n = 4 retina per group; repeated twice. Scale bar, 50 µm.
