αB-crystallin mini-peptides support corneal healing in vitro and in vivo in rabbit model

To evaluate if topical use of αB-crystallin mini-peptides supports corneal healing following flap surgery.

Cultured corneal cells were treated with fluorescent tagged αB-crystallin mini-peptides to assess its internalization. Cultured corneal cells pre-treated with or without the mini-peptides were exposed to H₂O₂ and cell viability was examined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Elongation of neurites of cultured trigeminal neurones was examined following treatment either with αB-crystallin mini-peptides or protein. Cultured trigeminal neurones were pre-treated either with αB-crystallin mini-peptides or crystallin protein and exposed to H₂O₂ and presence of beading in the dendrites and axons was assessed. Corneal flap surgery was conducted on rabbit cornea and treated topically either with αB-crystallin peptide (0.5 mg/mL thrice daily for 14d) or phosphate-buffered saline (PBS). Corneal healing was evaluated under slit-lamp biomicroscope, mRNA expression of inflammatory cytokines were assessed and the corneas were evaluated by histopathology.

Internalization of αB-crystallin mini-peptides was ascertained by the detection of fluorescence within the corneal cells. The MTT assay revealed that treatment with αB-crystallin mini-peptide reduced cell death induced by H₂O₂ treatment. The mini-peptides did not influence the elongation of trigeminal neurites, but significantly (P<0.05) reduced beading in the neurites. In rabbit eye, the treated corneas showed reduced hyper-reflective zones (P<0.05) and suppression in the expression of inflammatory cytokines. Histopathological examination also revealed reduction of inflammatory response in treated corneas.

The αB-crystallin mini-peptides restrict the damage to corneal cells and neurons and aids in corneal healing.