MSC transplantation increased RGC axon regeneration 16 and 28 days after optic nerve crush.

A-D: Photomontage of confocal images of optic nerve sections to illustrate axonal outgrowth. CTB-488 was injected into the vitreous body 2 days prior to euthanasia to label the axons. Sixteen days after nerve crush (A,B,E) only a few axons had crossed the lesion site (asterisk) in the vehicle-injected animals (A) and this number was larger in the MSC-injected animals (B). Twenty-eight days after optic nerve injury (C,D,F), the MSC-injected group had an even larger number of axons regenerating beyond the crush site, compared to the vehicle-injected group. E, F: Quantification of CTB-488+ axons per nerve at different distances from the crush site (from 0.25 to 2.0 mm). Results are displayed as mean ± SEM. *P<0.05; **P<0.01. Scale bar: 200 µm.