Fig. 4

Splenectomy and ATR1 inhibition curbs subretinal pathogenic inflammation in hyperinflammatory TRE2 mice that express the AMD-risk APOE 2 isoform. A Representative images of IBA1 (MP marker) stained RPE flatmounts of TRE2 mice, after preventive (-30 days) sham or splenectomy surgeries, exposed for 4 days to 4500 lx of green light (which induces subretinal MP accumulation in these mice). Quantification of subretinal IBA1⁺ MPs (n = 22, Mann–Whitney test, sham vs splenectomy *p = 0.0052). Scale bar = 50µm. B Representative images of IBA1-stained RPE flatmounts of PBS vs losartan (10 mg/kg) treated 3-month-old male TRE2 mice exposed for 4 days to 4500 lx of green light. Quantification of subretinal IBA1⁺ MPs in the subretinal space (Mann–Whitney test, PBS (n = 8) vs Losartan (n = 16), *p = 0.0135). Scale bar = 50µm. C and D Representative images of IBA1 (green, C) and PNA (red, cone marker, D) stained RPE and retinal flatmounts and quantification of IBA1⁺ MP (C) and PNA⁺ cone (D) density from 15-month-old TRE2 mice that underwent sham or splenectomy surgery (at 12 months) (n = 10; Mann–Whitney test, Sham vs Splenectomy, MP density (C): *p = 0.0317, cone density (D): *p = 0.003). E and F Representative images of IBA1 (green, E) and PNA (red, F) stained RPE and retinal flatmounts and quantification of IBA1⁺ MP (E) and PNA⁺ cone (F) density from 15-month-old TRE2 mice that were treated with water vs Losartan (30 mg/kg/day from 12 to 15 months) (n = 10; Mann–Whitney test, water vs losartan, MP density (E) *p = 0.0374; cone density (F) *p = 0.0256). Scale bar = 50 µm. ATR1: angiotensin II receptor type 1; RPE: retinal pigment epithelium; IP injection: intraperitoneal injection; MP: mononuclear phagocyte