Low decorin expression along with inherent activation of ERK1,2 in ear lobe keloids

Abstract 

Over production of collagen and its abnormal assembly is the hallmark of abnormal scars such as keloids, a condition which reflects fibrosis of the skin. Fibrotic conditions of organs such as liver, lungs and eyes are characterized by low levels of decorin, a member of the small leucine proteoglycan family, which is an indispensable modulator of collagen assembly. Involvement of decorin in keloids is not well described, therefore, its expression in keloids was studied here. We showed low decorin levels in the total tissue extract of keloids as compared to normal skin. Further, we showed that this low level is due to reduced transcription of decorin by keloid fibroblasts. As decorin can also act as an intermediate signaling molecule involved in the ERK1,2 pathway, levels of both ERK1,2 and its activated counterpart were studied and found to be up-regulated in keloids. Through this study a novel attempt has been made to understand the implications of decorin expression and a possible cause of over production of collagen and its aberrant assembly in keloids is suggested.

Abbreviations: ECM, extra cellular matrix, ERK, extra cellular signal regulated kinase, SLRP, small leucine-rich proteoglycans

Keywords: Keloid, Decorin, Collagen, Extra cellular matrix, ERK1,2