Effect of Topical Na-Hyaluronan on Hemidesmosome Formation in n-Heptanol-Induced Corneal Injury

Abstract

The present study investigated the effect of Na-hyaluronan (Na-HA) on the hemidesmosome morphogenesis in n-heptanol-induced corneal wounds. Central epithelial wounds were induced in the rabbit cornea by applying a 5.5-mm round filter paper, which was soaked in n-heptanol, for 60 s. 1% Na-HA in phosphate-buffered saline (PBS) or PBS alone were topically administered to the wounded cornea 4 times daily for up to 7 days. Epithelial healing rates during the first 2 days were not altered by Na-HA. The number of hemidesmosomes in the basement membrane of the central cornea was significantly increased in both 3- and 7-day groups after treatment with 1% Na-HA. The results suggest that topically applied 1% Na-HA may enhance the formation of hemidesmosomes during the early healing phase in n-heptanol-induced corneal wounds.

Positive Influence of Hyaluronate on Cell Vitality of Human Conjunctival Cells after Alkali Injuries

“…Unfortunately, the exact role of the endogenously produced HA in the corneal wound healing process is as yet unknown. Topically applied HA seems to suppress corneal stromal infiltration by polymorphonuclear leucocytes [20]. …”

“…The biological actions of HA such as promotion of cell adhesion, migration, proliferation and differentiation are thought to be mediated by an interaction with a cell surface receptor associated with actin filaments, which is preferentially expressed in actively proliferating cells [20]. …”

Effect of Na-Hyaluronan on Stromal and Endothelial Healing in Experimental Corneal Alkali Wounds

“…In alkali-wounded eyes and other ocular surface disorders, different concentrations of Na-HA have been applied either clinically or experimentally [9,[15][16][17][18][19][20]35]. Na-HA has been reported to provide better protection of the corneal epithelium and endothelium [15][16][17][18][19][20] to stimulate corneal epithelial migration and proliferation [9,13,35] and to enhance hemidesmosome morphogenesis [12]. Few studies have, however, been performed to evaluate the efficacy of Na-HA on stromal and endothelial healing.…”

“…Hyaluronan (HA), which is synthesized in the cell membrane, was previously regarded as a biologically inert viscous substance but was subsequently shown to be involved in cell protection, control of cell migration and growth, cell differentiation and tissue morphogenesis [11][12][13]. HA is widely distributed in connective tissues as an important constituent of the extracellular matrix [14].…”

“…HA is widely distributed in connective tissues as an important constituent of the extracellular matrix [14]. Numerous studies have been postulated that topically applied Na-HA has positive effects on epithelial healing in various types of corneal injury and ocular surface disorders [9,12,13,[15][16][17][18][19][20]. Previously we showed that topically applied 1% Na-HA both enhanced the formation of hemidesmosomes in epithelial healing after n-heptanol-induced wounds and stimulated the initial epithelial healing in alkali wounds [9,12].…”