Histone deacetylase inhibitors and candidate gene expression: An in vivo and in vitro approach to studying chromatin remodeling in a clinical population.
OBJECTIVE
The emerging field of psychiatric epigenetics is constrained by the dearth of research methods feasible in living patients. With this focus, we report on two separate approaches, one in vitro and one in vivo, developed in our laboratory.


METHODS
In the first approach, we isolated lymphocytes from 12 subjects and cultured their cells with either 0.7 mM valproic acid (VPA), 100 nM Trichostatin A (TSA), or DMSO (control) for 24h based upon previous dose response experiments. We then measured GAD67 mRNA expression using realtime RT-PCR, total acetylated histone 3 (H3K9,K14ac) levels using Western blot analysis, and attachment of H3K9,K14ac to the GAD67 promoter using ChIP. In the second approach, we measured GAD67 mRNA and total H3K9,K14ac levels in lymphocytes from 11 schizophrenia and 7 bipolar patients before and after 4 weeks of clinical treatment with Depakote ER (VPA).


RESULTS
In the first approach, VPA induced a 383% increase in GAD67 mRNA, an 89% increase in total H3K9,K14ac levels, and a 482% increase in H3K9,K14ac attachment to the GAD67 promoter. TSA induced comparable changes on all measures. In the second approach, bipolar subjects had significantly higher baseline levels of H3K9,K14ac compared to subjects with schizophrenia. Subjects with clinically relevant serum levels of VPA (> or = 65 microg/mL) showed a significant increase in GAD67 mRNA expression.


CONCLUSIONS
Our results utilizing two separate approaches for examining chromatin remodeling in real clinical time provide possible means to investigate epigenetic events in living patients.
Gavin
David P
DP
The Psychiatric Institute, University of Illinois at Chicago, 1601 West Taylor St., Chicago, IL 60612, USA.
Kartan
Saritha
S
Chase
Kayla
K
Jayaraman
Sundararajan
S
Sharma
Rajiv P
RP
D000107:Acetylation / Q000187:drug effects; D000328:Adult; D001714:Bipolar Disorder / Q000188:drug therapy / Q000378:metabolism*; D015153:Blotting, Western; D018929:Cell Culture Techniques; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D005786:Gene Expression Regulation / Q000187:drug effects; D005968:Glutamate Decarboxylase / Q000235:genetics / Q000378:metabolism*; D056572:Histone Deacetylase Inhibitors; D006657:Histones / Q000378:metabolism*; D006801:Humans; D006877:Hydroxamic Acids / Q000494:pharmacology; D008214:Lymphocytes / Q000187:drug effects / Q000201:enzymology*; D008297:Male; D008875:Middle Aged; D012333:RNA, Messenger / Q000187:drug effects / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012559:Schizophrenia / Q000188:drug therapy / Q000378:metabolism*; D015854:Up-Regulation / Q000187:drug effects; D014635:Valproic Acid / Q000494:pharmacology; D055815:Young Adult
D004791:Enzyme Inhibitors; D056572:Histone Deacetylase Inhibitors; D006657:Histones; D006877:Hydroxamic Acids; D012333:RNA, Messenger; C012589:trichostatin A; D014635:Valproic Acid; D005968:Glutamate Decarboxylase; C402565:glutamate decarboxylase 1