The Role of TRiC-enhanced Actin Folding in Leber Congenital Amaurosis

Abstract

Purpose: Mutations in TCP-1 ring complex (TRiC) have been associated with Leber Congenital Amaurosis (LCA). TRiC is involved in protein folding and has 8 essential subunits including CCT5. Herein, we studied the retina of TRiC mutant zebrafish to evaluate the possible role of impaired actin and tubulin folding in LCA. Methods: The cct5tf 212b retina was histologically studied using Toluidine Blue staining as well as TUNEL, BrdU-labeling, and Phalloidin assays. Retinal organisation was assessed by quantification of the cellularity utilising DAPI. Results: Laminar organization of cct5tf 212b retinas was intact. Enhanced apoptosis throughout the cct5tf 212b retina was not compensated by higher proliferation rates, leaving the cct5tf 212b retina smaller in size. Quantification of retinal layer cellularity demonstrated that specifically the numbers of the amacrine and the retinal ganglion cells were depleted, suggesting that the cct5tf 212b retina was not uniformly affected by the reduced actin folding. Conclusion: Whereas the current literature suggests that LCA is predominantly affecting retinal photoreceptor cells and the retinal pigment epithelium, cct5tf 212b analyses demonstrated the important role of folding of actin by TRiC, suggesting that cct5