Cyclooxygenase (COX) is the key
enzyme in the formation of
prostaglandins in
inflammation. In the present study the effects of biomedically relevant
hexose sugars (
glucose,
fructose,
galactose,
mannose) and
sucrose disaccharide on the expression of COX-1 and COX-2 genes were evaluated in granulation tissue fibroblasts,
hypertrophic scar fibroblasts and
keloid fibroblasts. The effects of three
isoforms (AA, AB and BB) of PDGF on COX gene expression in granulation tissue fibroblasts were also examined. All cell lines expressed COX-1
mRNA, whilst fibroblasts derived from abnormal
scars did not express COX-2
mRNA. COX-1
mRNA expression was decreased by
sugars in granulation tissue fibroblasts and increased in
hypertrophic scar fibroblasts. No major changes were seen in
keloid fibroblasts. On the other hand, COX-2
mRNA expression in granulation tissue fibroblasts was decreased dramatically in the presence of
fructose,
mannose and
sucrose and moderately in the presence of
galactose. All
isoforms of PDGF increased COX-1 and COX-2
mRNA expression in granulation tissue fibroblasts, the most marked increases being elicited by
PDGF-BB. All fibroblast cell lines studied expressed the COX-1 gene while the COX-2 gene was not expressed by abnormal
scar-derived fibroblasts. Further, granulation tissue fibroblasts seemed to behave differently under the influence of
sugars compared to
hypertrophic scar fibroblasts whilst
keloid fibroblasts seemed to be relatively unaffected by
sugars. In addition, the
PDGF-BB isoform is a potent inducer of COX-2 gene expression in
wound fibroblasts. These findings may be relevant to the development of abnormal
scars and indicate the need for further studies.