Effects of postmortem interval on biomolecule integrity in the brain
Corina Nagy1, Marissa Maheu, Juan Pablo Lopez
1From the McGill Group for Suicide Studies, Douglas Mental Health University Institute, Verdun (CN, MM, JPL, KV, CC, JAG, NM, GT); and Departments of Neurology and Neurosurgery (CN, MM, KV, JAG, MA), Human Genetics (JPL, CC, GT), and Psychiatry (NM), McGill University, Montreal, Quebec, Canada.
Journal of Neuropathology and Experimental Neurology
|April 14, 2015
Summary
Postmortem interval (PMI) does not significantly degrade key biomolecules like RNA, microRNA, and proteins in brain tissue. This stability supports the continued use of postmortem brain samples for neurologic and neuropsychiatric disorder research.
Area of Science:
- Neuroscience
- Molecular Biology
- Genetics
- Epigenetics
Background:
- Postmortem brain tissue is crucial for studying neurologic and neuropsychiatric disorders.
- Postmortem interval (PMI) is a significant confounder affecting biomolecule integrity in brain tissue studies.
Purpose of the Study:
- To assess the stability of RNA, microRNA, histone modifications, and proteins at various postmortem intervals.
- To evaluate the suitability of biomolecules in postmortem brain tissue for molecular and genetic studies.
Main Methods:
- Utilized Sprague-Dawley rats as an animal model.
- Examined biomolecule integrity under variable postmortem intervals at room temperature and a fixed 24-hour interval at 4°C.
- Investigated eight distinct time points to analyze degradation patterns.
Main Results:
- MicroRNA demonstrated remarkable resistance to extended postmortem intervals.
- Methylated histone modifications and histone proteins showed stability up to 72-96 hours.
- RNA degradation was transcript-specific, with higher expression genes degrading faster than housekeeping genes.
Conclusions:
- Key biomolecules commonly studied in genetic and epigenetic research are stable across investigated postmortem intervals.
- The findings support the ongoing utility of postmortem human brain tissue for neuropsychiatric research.
