Upregulation of transglutaminase in the goldfish retina during optic nerve regeneration

Abstract

To elucidate the molecular involvement of transglutaminase (TG) in central nervous system (CNS) regeneration, we cloned a full-length cDNA for neural TG (TGN) from axotomized goldfish retinas and produced a recombinant TGN protein from this cDNA. The levels of TGN mRNA and protein were increased at 10-30 days after optic nerve transection, and this increase in TGN was only localized in the ganglion cells in goldfish retinas. In retinal explant cultures, the recombinant TGN protein induced a drastic enhancement of neunte outgrowth, while TGN-specific RNAi significantly suppressed this neunte outgrowth. Taken together, these data strongly indicate that TGN is a key regulatory molecule for CNS regeneration.