Postmortem delay has minimal effect on brain RNA integrity.
The Bryan Alzheimer Disease Research Center obtains postmortem human brain tissue from patients with Alzheimer disease (AD) and cognitively normal control subjects for molecular and genetic research programs. A growing body of research suggests that variations in gene transcript levels may contribute to the onset and progression of disease. Identifying how the regulation of gene expression may affect AD requires the use of high-quality mRNA from banked human brains. The present study was conducted to establish the quality and suitability of available banked brain tissue for future gene expression studies. We chose 32 AD cases with Braak stage IV, V, or VI. These AD cases were matched to 36 normal control cases by age and sex when possible. Multiple regions from each brain were sampled, including frontal cortex, temporal cortex, occipital cortex, and cerebellum. Hippocampus was also available for study from 14 control cases. A comparison of several antemortem and postmortem variables, such as postmortem interval, agonal state, ventricular cerebrospinal fluid pH, and cause of death were analyzed. RNA was isolated from at least 1 area from every brain and most brains yielded intact RNA from all regions tested. Analysis of the clinical variables did not reveal any features that correlated with the ability to recover intact mRNA. We conclude that undegraded mRNA may be isolated from most brain regions many hours postmortem and that neither the pH of ventricular fluid nor postmortem interval is predictive of mRNA integrity.
Ervin
John F
JF
Department Medicine (Neurology), Joseph and Kathleen Bryan Alzheimer's Disease Research Center, Duke University Medical Center, Durham, North Carolina 27710, USA.
Heinzen
Erin L
EL
Cronin
Kenneth D
KD
Goldstein
David
D
Szymanski
Mari H
MH
Burke
James R
JR
Welsh-Bohmer
Kathleen A
KA
Hulette
Christine M
CM
D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000473:pathology; D001921:Brain / Q000378:metabolism* / Q000473:pathology; D005260:Female; D005786:Gene Expression Regulation; D006801:Humans; D008297:Male; D008875:Middle Aged; D009419:Nerve Tissue Proteins / Q000235:genetics* / Q000378:metabolism; D011180:Postmortem Changes; D012313:RNA / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D013048:Specimen Handling
D009419:Nerve Tissue Proteins; D012313:RNA