Effects of postmortem interval on biomolecule integrity in the brain.

TitleEffects of postmortem interval on biomolecule integrity in the brain.
Publication TypeJournal Article
Year of Publication2015
AuthorsNagy C, Maheu M, Lopez JPablo, Vaillancourt K, Cruceanu C, Gross JA, Arnovitz M, Mechawar N, Turecki G
JournalJ Neuropathol Exp Neurol
Volume74
Issue5
Pagination459-69
Date Published2015 May
ISSN1554-6578
Abstract

Postmortem brain research is invaluable to the study of neurologic and neuropsychiatric disorders, including Alzheimer disease, schizophrenia, and major depression. A major confounder in molecular studies using human brain tissue is postmortem interval (i.e. the amount of time between a subject's death and processing of tissue). We examined the integrity of biomolecules that were of interest to molecular studies of neurologic disorders, including RNA, microRNA, histone modifications, and proteins, at various postmortem intervals in an animal model to assess their robustness and suitability for experimentation. Sprague-Dawley rats were selected as model and subjected to 2 conditions: a variable postmortem interval at room temperature and a fixed time of 24 hours at 4°C, which simulates the period commonly spent in the morgue before brain collection. Eight time points were investigated. MicroRNA was impressively resistant to postmortem intervals; methylated histone modifications showed a threshold between 72 and 96 hours, mirroring results from histone proteins at 72 hours. RNA degradation was transcript-specific, with housekeeping genes being more robust than genes with lower expression. Our results suggest that molecules commonly investigated in genetic and epigenetic studies were highly stable through the postmortem intervals investigated. These results support the continued use of postmortem tissue for neuropsychiatric research.

DOI10.1097/NEN.0000000000000190
Alternate JournalJ. Neuropathol. Exp. Neurol.
PubMed ID25868148