ABSTRACT
The process of wound healing involves integrated events including inflammation, granulation tissue formation, matrix deposition and remodeling. Growth factors play a key role in the process. Among them transforming growth factor-beta1 [TGF-beta1] is known to accelerate tissue repair by promoting the synthesis and deposition of extracellular matrix proteins. However, persistence or overactivity of TGF-beta1 during the remodeling phase can potentially lead to fibrosis. The primary objective of this study was, therefore, to determine the effects of TGF-beta1 inactivation, by its latency associated peptide [LAP], on the cutaneous healing wounds. Excisional wounds were generated on the back of male adult rats. Wounds received TGF-beta1 or LAP during the post-inflammatory phase. Expression of type I collagen and - smooth muscle actin was evaluated by Western blotting. Wound maturation was further assessed by histology and immunohistochemical methods using specific antibody for proliferating cell nuclear antigen [PCNA]. Wounds treated with TGF-beta1 showed a marked increase in the level of type I collagen, whereas no significant changes were observed in the wounds treated with LAP as compared to that in control. Expression of -smooth muscle actin was markedly reduced in the wounds treated with LAP but was slightly increased in the wounds treated with TGF-beta1. Both neodermis and newly-formed epidermis exhibited a higher degree of maturation in the LAP-treated wounds as compared to TGF-beta1 treated wounds. Local administration of LAP seems to be beneficial to tissue remodeling. It promotes wound maturation and, may prevent fibrosis and hypertrophic scarring