Fig. 4: LBP promotes axon regeneration and survival of retinal ganglion cells (RGCs) after optic nerve crush (ONC).

a Mice received oral administration of LBP (100 mg/kg) for 21 days (7 days pre-treatment and 14 days post-treatment), and intravitreal injections with LBP at days 0 and 7 immediately after optic nerve crush (ONC). b Cholera toxin subunit B (CTB)-labeled regenerating axons were quantified in the tissue-cleared optic nerves. LBP-induced robust axon regeneration 2 weeks after ONC. Red dotted line indicated the crushed site. Scale bar: 200 µm. c Serial transverse cryosections (20µm-thick) of retinae were immunostained with anti-RBPMS for retinal ganglion cell (RGC) survival assay. RBPMS-positive RGCs were counted in every fifth section per retina (3–5 sections). LBP increased survival by nearly 2-folds, when compared with PBS controls. Scale bar: 20 µm. Mean ± SEM (n = 5–6 per group); *P < 0.05; Student’s t test in (b, c).