Protein Biomarkers for the Identification of Forensically Relevant Human Hair from Different Body Parts in Intimate Contact Cases

Correctly identifying the human hair anatomic location
found at
crime scenes can link biological sample donors with the actual crime
event, thus providing significant insight into the crime scene reconstruction.
Forensic proteomic studies on human hairs can facilitate the development
of new biomarkers for hair identification while compensating for the
limitations of the conventional morphologic hair comparison and DNA
analysis. Herein, the LC–MS/MS platform was used to find differentially
expressed protein biomarkers in hairs from different body sites. The
findings indicated that a total of 296 protein biomarkers with statistically
significant differences in body sites were initially identified, and
hair samples from the scalp, pubic, and armpit parts were distinguished
from each other, which were validated by multiple bioinformatic methods.
Fewer differences in protein patterns between armpit and pubic hairs
while larger differences between hair and armpit as well as pubic
hairs provided reasonable evidence of sexual or close intimate contact
in crimes. This study lays the foundation for the development of a
more reliable strategy to distinguish human hairs of various body
areas from Chinese and will also support microscopic hair comparison
analysis and assist in the proper handling of legal proceedings in
relative cases by judicial officers, deserving special attention and
further in-depth investigation. The MS proteomics data have been deposited
to the ProteomeXchange Consortium via the iProX partner repository
with the dataset identifier PXD038173.