Carbohydrates and Epithelial Repair - More Than Just Post-Translational Modification

Abstract

Epithelia are the layers of cells that form barriers between external milieu and underlying tissues and thus, are important components of most organs of the body. Epithelial layers of organs, such as the lung, are exposed to various challenges resulting in frequent injury. Epithelial wound healing represents an important process by which repair restores the physical barrier lost as a result of cell damage and apoptosis. The repair of epithelial layers consists of a series of ordered events including epithelial cell spreading, migration proliferation and, differentiation. Carbohydrates attached to cell surface proteins and lipids can modulate the function of structures that they are conjugated to and therefore, can affect cell behavior. Although the basic mechanisms of epithelial repair are not entirely understood, many studies suggest glycoconjugates attached to proteins on the cell surface of epithelial cells play important roles in many of these cellular processes. In the present review, the role of carbohydrates in epithelial repair of different organs, including the sources of epithelial injury and current models of epithelial repair will be discussed with a focus on our understanding of the airway epithelium. With a better understanding of carbohydrates and their role in epithelial repair, new therapeutic targets for diseases involving damage to the epithelium can be identified.

Re-epithelialization of adult skin wounds: Cellular mechanisms and therapeutic strategies

“…Glycated proteins act through receptors of AGEs activating pathways, the NF-kB-mediated inflammation pathway, and ERK-and PI3K/Akt signalling [141]. The link between carbohydrates and epithelial repair suggests that glycation events may have deleterious effects [142]. Studies have revealed that more AGEs are concentrated, the less keratinocytes will be activated.…”

Wound healing in the 21st century

“…A review of these effects has been published recently, 54 and the link between carbohydrates and epithelial repair has been studied in great detail. 55 The fact that AGEs also modify dermal fibroblast proliferation 56 underlines the clinical observation of extremely difficult wound care in patients with diabetes. These pathways are integrated via the highly conserved mTOR 30 and represent important signaling cascades in wound healing and pathogenesis.…”

IL-13, Asthma and Glycosylation in Airway Epithelial Repair

“…Increased presentation of sLex was observed in areas of epithelial damage relative to areas of intact epithelium. In an in vitro model of bronchial epithelial repair, cell surface expression of sLex was shown to be significantly increased following mechanical injury of airway epithelial cell monolayers and inhibition of sLex completely prevented repair [86]. Further studies demonstrated that sLex decoration of epidermal growth factor receptor (EGFR) plays an important role in mediating airway epithelial wound repair [87].…”