title: miRNA analysis in vitreous humor to determine the time of death: a proof-of-concept pilot study.
abstract: We hypothesized that miRNAs present in vitreous humor could be a sort of "biological black box," storing information about physiological and environmental circumstances at death. As a proof of concept, we analyzed the vitreous humor miRNA signature to explore its forensic potential applications, such as determining the time of the day at death. The miRNAs present in vitreous humor from individuals who died at daytime or at nighttime were analyzed by quantitative real-time polymerase chain reaction (qPCR) array. Target miRNAs showing significant differences between groups were studied in a larger sample by individual qPCR assays. After array analysis of miRNAs in seven samples, significant expression differences were detected between individuals who died at daytime and at nighttime regarding mir-34c, mir-541, mir-888, mir-484, and mir-142-5p. miR-222 appeared as the best reference gene. The results were replicated in 34 vitreous humor samples, and the day-night differences were confirmed for miR-142-5p and miR-541, suggesting that miRNA levels may be related to either the ambient light or the circadian clock at the time of death. There was no correlation between miRNA levels and the time elapsed after death, suggesting that they were stable at least for 24 h. In conclusion, this report supports the potential forensic utility of the analysis of miRNAs in the vitreous humor in applications such as determining the time of death.
authors.affiliation: Unit of Legal Medicine, University of Cantabria, Av Herrera oria sn, 39011 Santander, Spain.
authors.forename: Adrián
authors.initials: A
authors.lastname: Odriozola
authors.forename: José A
authors.initials: JA
authors.lastname: Riancho
authors.forename: Rosa
authors.initials: R
authors.lastname: de la Vega
authors.forename: Gloria
authors.initials: G
authors.lastname: Agudo
authors.forename: Ana
authors.initials: A
authors.lastname: García-Blanco
authors.forename: Elena
authors.initials: E
authors.lastname: de Cos
authors.forename: Fidel
authors.initials: F
authors.lastname: Fernández
authors.forename: Carolina
authors.initials: C
authors.lastname: Sañudo
authors.forename: María T
authors.initials: MT
authors.lastname: Zarrabeitia
mesh_terms: D001344:Autopsy / Q000379:methods*; D002940:Circadian Rhythm / Q000235:genetics*; D005260:Female; D053803:Forensic Genetics / Q000379:methods*; D020869:Gene Expression Profiling; D006801:Humans; D016014:Linear Models; D008297:Male; D035683:MicroRNAs / Q000032:analysis*; D008875:Middle Aged; D010865:Pilot Projects; D060888:Real-Time Polymerase Chain Reaction; D012680:Sensitivity and Specificity; D013997:Time Factors; D014822:Vitreous Body / Q000737:chemistry*
chemical_list: D035683:MicroRNAs