Fig. 3

Tppp3 promotes axon regeneration and improves RGC survival. A Scheme of experimental setup for ONC and sample collection. AAV2 vectors were intravitreally injected into eyes two weeks before ONC. Two days before sample collection, CTB-555, an anterograde tracer, was intravitreally injected into eyes to label regenerating axons. Optic nerves and retinas were collected two weeks after ONC. B Representative images of optic nerve sections transduced with AAV2 vectors and labeled with CTB-555. Tppp3 overexpression significantly increases CTB-555+ axons two weeks after ONC. The crush site is marked with an asterisk. The optic nerve's proximal end (towards the eye globe) is located on the left, and the distal end (towards the brain) is on the right. Scale bar = 100 μm. C Quantification of the number of CTB-555+ axons at varying distances from the crush site after transduction with AAV2-control (n = 6 optic nerves) or AAV2-Tppp3-OE (n = 8 optic nerves). Tppp3 overexpression improves RGC regeneration at short distances from the crush site. Statistical significance was determined using an unpaired student’s t-test for each distance (**p < 0.01). Mean ± SEM is shown. D Representative images of RBPMS+ cells in flatmount retinas of (D i) negative controls without AAV transduction and ONC, or transduced with (D ii) AAV-CMV or (D iii) AAV-Tppp3-OE. Scale bar = 50 μm. E Tppp3 overexpression improves RGC survival following ONC. Quantification of the mean number of RBPMS+ RGCs in flatmount retinas after transduction with control AAV2-CMV or AAV2-Tppp3-OE, compared to the negative control without AAV2 transduction and ONC (n = 6 retinas). Statistical significance was determined using an unpaired student’s t-test (****p < 0.0001, **p < 0.01). Mean ± SEM is shown. F TPPP3 protein expression is significantly decreased in the optic nerve after ONC compared to sham control