title: No association between global leukocyte DNA methylation and homocysteine levels in schizophrenia patients.
abstract: Meta-analysis recently suggested that a 5 muM increase in homocysteine is associated with a 70% higher risk for schizophrenia. Elevated homocysteine is reported to alter macromolecule methylation. We studied whether elevated plasma homocysteine levels in schizophrenia are associated with altered leukocyte global DNA methylation. DNA was extracted from peripheral blood leukocytes of 28 schizophrenia patients vs. 26 matched healthy controls. Percent of global genome DNA methylation was measured using the cytosine-extension method. Homocysteine levels were higher in schizophrenia patients than in controls. No difference in global DNA methylation between schizophrenia patients and control subjects was found (74.0%+/-14.8 vs. 69.4+/-22.0, p=0.31). A significant interaction between diagnosis and smoking on DNA methylation was obtained (F=6.8, df=1,47, p=0.032). Although leukocytes may be a useful cell model to evaluate epigenetic changes such as global DNA methylation in brain, future studies should compare global DNA methylation in peripheral tissue vs. brain in laboratory animals.
authors.affiliation: Faculty of Health Sciences, Stanley Research Center, Ben-Gurion University of the Negev & Beersheva Mental Health Center, Beersheva, Israel.
authors.forename: A
authors.initials: A
authors.lastname: Bromberg
authors.forename: J
authors.initials: J
authors.lastname: Levine
authors.forename: B
authors.initials: B
authors.lastname: Nemetz
authors.forename: R H
authors.initials: RH
authors.lastname: Belmaker
authors.forename: G
authors.initials: G
authors.lastname: Agam
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D014150:Antipsychotic Agents / Q000494:pharmacology / Q000627:therapeutic use; D016022:Case-Control Studies; D015331:Cohort Studies; D003538:Cystamine / Q000031:analogs & derivatives* / Q000097:blood; D019175:DNA Methylation; D044127:Epigenesis, Genetic / Q000502:physiology; D005260:Female; D006801:Humans; D007962:Leukocytes / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D012559:Schizophrenia / Q000097:blood* / Q000188:drug therapy / Q000473:pathology*; D012737:Sex Factors
chemical_list: D014150:Antipsychotic Agents; C029174:homocystamine; D003538:Cystamine