title: Elevated levels of human endogenous retrovirus-W transcripts in blood cells from patients with first episode schizophrenia.
abstract: We previously reported on the differential presence of transcripts related to the human endogenous retrovirus (HERV)-W family in cerebrospinal fluid and plasma from patients with first-episode schizophrenia compared with control individuals. Whether this is a consequence of qualitative or quantitative differences in transcription of genomic regions harboring HERV-W elements is not known. The purpose of the present study was therefore to characterize the transcribed HERV-W elements in mononuclear cells obtained from 30 patients first hospitalized for schizophrenia-related psychosis and from 26 healthy control individuals. We observed elevated total levels of HERV-W gag (2.1-fold, P < 0.01) but not env transcripts in the cells of patients compared with controls. By using the melting temperatures of the amplicons as a proxy marker for sequence identity, no absolute qualitative differences was detected between the two groups. Mapping of the detected transcripts identified several intronic and intergenic HERV-W elements transcribed in the cells, including elements previously considered transcriptionally silent. Element-specific assays revealed elevated levels of intronic transcripts containing HERV-W gag sequence from the putative gene PTD015 on chromosome 11q13.5 (1.6-fold, P < 0.05) in the patients compared with the controls. Thus, studies aiming to further understanding of complex human disease such as schizophrenia may need to be extended beyond the strictly protein-coding fraction of the transcriptome.
authors.affiliation: Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Y
authors.initials: Y
authors.lastname: Yao
authors.forename: J
authors.initials: J
authors.lastname: Schröder
authors.forename: C
authors.initials: C
authors.lastname: Nellåker
authors.forename: C
authors.initials: C
authors.lastname: Bottmer
authors.forename: S
authors.initials: S
authors.lastname: Bachmann
authors.forename: R H
authors.initials: RH
authors.lastname: Yolken
authors.forename: H
authors.initials: H
authors.lastname: Karlsson
mesh_terms: D002880:Chromosomes, Human, Pair 11; D020077:Endogenous Retroviruses / Q000235:genetics*; D020869:Gene Expression Profiling; D015967:Gene Expression Regulation, Viral / Q000502:physiology; D015683:Gene Products, gag / Q000235:genetics; D006801:Humans; D007438:Introns / Q000235:genetics; D008214:Lymphocytes / Q000821:virology; D011618:Psychotic Disorders / Q000235:genetics / Q000821:virology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012559:Schizophrenia / Q000235:genetics / Q000821:virology*; D017422:Sequence Analysis, DNA; D014158:Transcription, Genetic / Q000235:genetics*; D014759:Viral Envelope Proteins / Q000235:genetics
chemical_list: D015683:Gene Products, gag; D014759:Viral Envelope Proteins