title: Limited predictability of postmortem human brain tissue quality by RNA integrity numbers.
abstract: The RNA integrity number (RIN) is often considered to be a critical measure of the quality of postmortem human brains. However, it has been suggested that RINs do not necessarily reflect the availability of intact mRNA. Using the Agilent bioanalyzer and qRT-PCR, we explored whether RINs provide a meaningful way of assessing mRNA degradation and integrity in human brain samples by evaluating the expression of 3'-5' mRNA sequences of the cytochrome C-1 (CYC1) gene. Analysis of electropherograms showed that RINs were not consistently correlated with RNA or cDNA profiles and appeared to be poor predictors of overall cDNA quality. Cycle thresholds from qRT-PCR analysis to quantify the amount of CYC1 mRNA revealed positive correlations of RINs with amplification of full-length transcripts, despite the variable degree of linear degradation along the 3'-5' sequence. These data demonstrate that in postmortem human brain tissue the RIN is an indicator of mRNA quantity independent of degradation, but does not predict mRNA integrity, suggesting that RINs provide an incomplete measure of brain tissue quality. Quality assessment of postmortem human brains by RNA integrity numbers (RINs) may be misleading, as they do not measure intact mRNAs. We show that the RIN is an indicator of mRNA quantity independent of degradation, but does not predict mRNA integrity, suggesting that RINs provide an incomplete measure of brain tissue quality. Our results resolve controversial assumption on interpreting quality assessments of human postmortem brains by RINs.
authors.affiliation: Division of Basic Neuroscience, Department of Psychiatry, Harvard Brain Tissue Resource Center, McLean Hospital/Harvard Medical School, Belmont, Massachusetts, USA.
authors.forename: Kai-C
authors.initials: KC
authors.lastname: Sonntag
authors.affiliation: Division of Basic Neuroscience, Department of Psychiatry, Harvard Brain Tissue Resource Center, McLean Hospital/Harvard Medical School, Belmont, Massachusetts, USA.
authors.forename: George
authors.initials: G
authors.lastname: Tejada
authors.affiliation: Division of Basic Neuroscience, Department of Psychiatry, Harvard Brain Tissue Resource Center, McLean Hospital/Harvard Medical School, Belmont, Massachusetts, USA.
authors.forename: Sivan
authors.initials: S
authors.lastname: Subburaju
authors.affiliation: Division of Basic Neuroscience, Department of Psychiatry, Harvard Brain Tissue Resource Center, McLean Hospital/Harvard Medical School, Belmont, Massachusetts, USA.
authors.forename: Sabina
authors.initials: S
authors.lastname: Berretta
authors.affiliation: Division of Basic Neuroscience, Department of Psychiatry, Harvard Brain Tissue Resource Center, McLean Hospital/Harvard Medical School, Belmont, Massachusetts, USA.
authors.forename: Francine M
authors.initials: FM
authors.lastname: Benes
authors.affiliation: Division of Basic Neuroscience, Department of Psychiatry, Harvard Brain Tissue Resource Center, McLean Hospital/Harvard Medical School, Belmont, Massachusetts, USA.
authors.forename: Tsung-Ung W
authors.initials: TU
authors.lastname: Woo
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001921:Brain / Q000378:metabolism* / Q000473:pathology*; D002478:Cells, Cultured; D003575:Cytochromes c1 / Q000235:genetics*; D005347:Fibroblasts; D020869:Gene Expression Profiling; D006801:Humans; D001523:Mental Disorders / Q000473:pathology; D008875:Middle Aged; D019636:Neurodegenerative Diseases / Q000473:pathology; D011180:Postmortem Changes; D011237:Predictive Value of Tests; D012313:RNA / Q000378:metabolism*; D020871:RNA Stability / Q000502:physiology; D012333:RNA, Messenger / Q000378:metabolism; D055815:Young Adult
chemical_list: D012333:RNA, Messenger; D012313:RNA; D003575:Cytochromes c1
keywords: Agilent bioanalyzer; RNA integrity number RIN; cytochrome C-1 CYC1; postmortem human brains; quantitative real-time polymerase chain reaction qRT-PCR