Figure 4. Protein kinase A (PKA) blocked hydrogen peroxide (H₂O₂)-mediated activation of NLR family pyrin domain containing 3 (NLRP3) pathway proteins. Western blot for retinal endothelial cells (RECs) grown in normal glucose (NG) and treated with H₂O₂ or forskolin, a PKA agonist (Panel A). Panels B–D are Western blot results for NLRP3 (B), ASC1 (C), and cleaved caspase 1 (D). Panel E shows the ELISA results for IL-1β in the same treatments. n = 6. Data are mean ± SEM *p < 0.05 versus NG, # p < 0.05 versus NG + H₂O₂.