Reduced expression of the gap junction protein Connexin 43 in keratoconus

Abstract

Purpose The purpose of the present study was to examine whether keratoconus, which is a bilateral noninflammatory corneal ectasia with multifactorial aetiology, shows altered expression of Connexin (Cx43). Cx43 is an important gap junction protein that contributes crucially to epithelial and stromal integrity of cornea. Methods Eight keratoconic human corneal buttons were examined with immunohistochemistry and Western blotting and compared with eight normal human corneal buttons, to unravel changes in Cx43 expression. Results All normal corneas exhibited similar epithelial Cx43 expression patterns, with the protein located in the basal epithelial layer. In contrast, some keratoconic corneas showed an altered pattern of immunostaining and Western blotting confirmed a decreased expression of Cx43 in keratoconic corneas. Conclusions Our results indicate that a decrease in Cx43 amount together with functional alteration of the protein is associated with keratoconus pathophysiology However, these changes apply only to some of the corneas examined and may not generally account for the development of keratoconus.

RNA-Seq analysis and comparison of corneal epithelium in keratoconus and myopia patients

“…These functions are important in the healthy corneal epithelium which is constantly undergoing renewal through the processes of cell division, migration and differentiation. These functional classifications are consistent with histological observations of KC epithelium, which typically appear flattened and thinned, with fewer layers and diminished architecture of the basal and wing cell layers, associated with changes in cell-cell junctions and loss of cell polarity 3 , 5 , 37 . The regulation of hydrolase activity category was also down-regulated, however the hydrolase-related DEGs identified in our study did not include the previously suggested MMPs and TIMPs 20 .…”

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

“…In the cornea, the regulation of cell shedding establishes a foundation for corneal tissue engineering, enabling maintenance of cell growth (i.e. prevention of cell death), and potentially the treatment of corneal thinning diseases such as keratoconus (Gatzioufas et al., 2007).…”

Role of the JNK Signaling PathWay in Downregulation of Connexin43 by TNF-α in Human Corneal Fibroblasts

“…37 We have previously shown that Cx43 is expressed in the normal rabbit corneal epithelium and that its expression in this tissue is lost during wound healing. 38 Moreover, immortalized corneal epithelial cells were found to have lost the expression of Cx43 and GJIC.…”