Quantitative analysis of focused a-to-I RNA editing sites by ultra-high-throughput sequencing in psychiatric disorders.
A-to-I RNA editing is a post-transcriptional modification of single nucleotides in RNA by adenosine deamination, which thereby diversifies the gene products encoded in the genome. Thousands of potential RNA editing sites have been identified by recent studies (e.g. see Li et al, Science 2009); however, only a handful of these sites have been independently confirmed. Here, we systematically and quantitatively examined 109 putative coding region A-to-I RNA editing sites in three sets of normal human brain samples by ultra-high-throughput sequencing (uHTS). Forty of 109 putative sites, including 25 previously confirmed sites, were validated as truly edited in our brain samples, suggesting an overestimation of A-to-I RNA editing in these putative sites by Li et al (2009). To evaluate RNA editing in human disease, we analyzed 29 of the confirmed sites in subjects with major depressive disorder and schizophrenia using uHTS. In striking contrast to many prior studies, we did not find significant alterations in the frequency of RNA editing at any of the editing sites in samples from these patients, including within the 5HT(2C) serotonin receptor (HTR2C). Our results indicate that uHTS is a fast, quantitative and high-throughput method to assess RNA editing in human physiology and disease and that many prior studies of RNA editing may overestimate both the extent and disease-related variability of RNA editing at the sites we examined in the human brain.
Department of Pharmacology, University of North Carolina Chapel Hill Medical School, Chapel Hill, North Carolina, United States of America.
Hu
H
Zhu
Daniel J
DJ
Urban
Jared
J
Blashka
Matthew T
MT
McPheeters
Wesley K
WK
Kroeze
Piotr
P
Mieczkowski
James C
JC
Overholser
George J
GJ
Jurjus
Lesa
L
Dieter
Gouri J
GJ
Mahajan
Grazyna
G
Rajkowska
Zefeng
Z
Wang
Patrick F
PF
Sullivan
Craig A
CA
Stockmeier
Bryan L
BL
Roth
D001483:Base Sequence; D001921:Brain / Q000378:metabolism*; D003865:Major Depressive Disorder / Q000235:genetics*; D059014:High-Throughput Nucleotide Sequencing; D006801:Humans; D008969:Molecular Sequence Data; D016366:Open Reading Frames / Q000235:genetics*; D017393:RNA Editing / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012559:Schizophrenia / Q000235:genetics*