Antisense down regulation of connexin31.1 reduces apoptosis and increases thickness of human and animal corneal epithelia

The roles of the gap junction protein connexin31.1 (Cx31.1) are poorly understood, especially as the protein appears to form non-functional channels. Cx31.1 specific antisense oligodeoxynucleotides (ODNs) were designed to evaluate its roles in a corneal epithelium model. Expression of Cx31.1 in corneal epithelium extends from the suprabasal layers of polyhedral wing cells through to the flat squamous cells of superficial layers which are shed into the tear film. Deoxyribozymes (Dzs) were tested for cleavage efficacy using in vitro transcribed Cx31.1 mRNA. Cleavage results showed a putative tertiary structure for Cx31.1 mRNA with one region appearing to have a higher potential for antisense targeting. Application of antisense ODNs designed to this region caused Cx31.1 knockdown in rat and human corneal organotypic culture models, leading to a reduction in apoptosis and a thickening of the corneal epithelium (p = 0.0045). Cx31.1 appears to play a role in triggering cell death; knocking it down may provide a novel approach for tissue repair and engineering.