The use of proteomics to study wound healing: a preliminary study for forensic estimation of wound age

Proteomics is the analysis of the protein complement of the genome. The technique involves extracting proteins from the tissue being examined; separating the proteins using methods such as two-dimensional gel electrophoresis and then identifying the proteins by mass spectrometry. This paper describes the application of proteomics to incised wounds of the rat to determine if this technology could be applied to the important forensic issue of determining the age of wounds. Experimental incised skin wounds were inflicted on rats 5, 15, 30 and 60 minutes, 3, 6, 12 and 24 hours and 2, 5, 7 and 12 days before euthanasia. Each wound was excised and frozen at 80 degrees C; protein extracts were prepared and subjected to two-dimensional polyacrylamide gel electrophoresis over the range pH 3 to pH 10. Protein spots were identified using Matrix-assisted Laser Desorption/Ionisation Time-of-Flight (MALDI-TOF) mass spectrometry. A number of proteins were identified in skin wounds. After wounding the most prominent change was in the level of haemoglobin, which was elevated in wounds five minutes old and remained elevated for three hours, falling to near control levels after 12 hours. This pilot study has illustrated the feasibility for proteomics to be applied to determining wound age.