Figure 6.

Alpha-1 antitrypsin (AAT) suppressed pro-inflammatory M1 microglial polarization during retinal degeneration. (A). In retinal whole mounts, the amount of CD16/32⁺IBA1⁺ M1 microglia in the central, mid-peripheral, and peripheral retina decreased significantly after AAT supplement. Scare bar, 50 µm. Depicted is mean ± SEM of three fields/eyes from six eyes. *p < 0.05 (two-tailed unpaired t-test). (B) In the retinal section, CD16/32⁺IBA1⁺ microglia prominently accumulated in the outer nuclear layer in PBS treatment group whereas the amount of CD16/32⁺IBA1⁺ pro-inflammatory microglia significantly decreased in the AAT-treated group. Scare bar, 20 µm. (C) In the cultured microglia under oxidative stress by hydrogen peroxide stimulation, AAT supplement significantly suppressed the pro-inflammatory M1 phenotype of microglia, presenting with less CD16/32⁺ cells co-stained with IBA1⁺ cells. Scare bar, 20 µm.