Protein profiling of keloidal scar tissue

Clinically, keloids are defined as scars that invade adjacent healthy tissue and are caused by tissue injury; however, the clear distinction relating keloids to wound healing or to cancer remains elusive. This study profiled protein extracts from the regions of keloid tissues to determine the activities within these different zones, and to help underpin the activities apparent within different regions of the disease. Two-dimensional gel electrophoresis, liquid chromatography mass spectrometer (LCMS) and a Mascot online database search were employed for comparative proteomic analysis between four sites in keloidal scars (KS). Out of 400 spots identified in all gels, 21 were unique to given KS sites. These were identified using LCMS and the results showed the presence of mitochondrial and structural proteins in the margin, while the top contained keratin II. Heat shock protein was the only protein present in the internal normal control and margin, while the external normal contain keratin II and the voltage-dependent anion-selective channel protein, annexin A6, plus glial fibrillary acidic protein. This work is novel since it has identified differentially expressed proteins across the tested keloidal scar sites. The presence of mitochondrial-associated proteins at the margins suggests that this is the most active part of the scar.