title: Differential display polymerase chain reaction reveals increased expression of striatal rat glia-derived nexin following chronic clozapine treatment.
abstract: Clozapine is considered a prototype of the 'so-called' atypical antipsychotic drug class. It has affinity for a broad range of receptors and, in comparison to typical antipsychotic drugs, produces less extrapyramidal side effects. However, its mechanism of action remains unclear. Differential display polymerase chain reaction (ddPCR) was implemented in this study to contribute to the current understanding of this mechanism at the genetic level and to identify novel genes regulated by clozapine. This technique generated approximately 2400 gene sequences that were analyzed for differential gene expression following protracted clozapine treatment. One of these sequences, originally termed Clozapine Regulated Gene (CRG), was shown to be significantly upregulated following the treatment. Northern hybridization confirmation of this finding revealed that chronic clozapine administration caused a five-fold increase in CRG mRNA. Elongation of the 5'- and 3'-ends of CRG indicated that the fragment was in fact rat glia-derived nexin mRNA. Western blotting demonstrated that levels of the mRNA's associated protein also increased comparably (three-fold) following chronic treatment with the antipsychotic drug. This study presents a possible neuroprotective role of nexin in clozapine treatment, particularly in the prevention of neuronal proteolytic degradation, since nexin has been shown to be a protease inhibitor.
authors.affiliation: Department of Psychiatry and Behavioural Neurosciences, McMaster University, Hamilton, ON, Canada.
authors.forename: V Z
authors.initials: VZ
authors.lastname: Chong
authors.forename: W
authors.initials: W
authors.lastname: Costain
authors.forename: J
authors.initials: J
authors.lastname: Marriott
authors.forename: S
authors.initials: S
authors.lastname: Sindwani
authors.forename: D J
authors.initials: DJ
authors.lastname: Knauer
authors.forename: J-F
authors.initials: JF
authors.lastname: Wang
authors.forename: L T
authors.initials: LT
authors.lastname: Young
authors.forename: D
authors.initials: D
authors.lastname: MacCrimmon
authors.forename: R K
authors.initials: RK
authors.lastname: Mishra
mesh_terms: D000595:Amino Acid Sequence; D016564:Amyloid beta-Protein Precursor; D000818:Animals; D001483:Base Sequence; D002352:Carrier Proteins / Q000096:biosynthesis* / Q000235:genetics; D003024:Clozapine / Q000008:administration & dosage*; D003342:Corpus Striatum / Q000187:drug effects* / Q000378:metabolism*; D020869:Gene Expression Profiling / Q000379:methods*; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology; D006801:Humans; D008297:Male; D051379:Mice; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction / Q000379:methods*; D058255:Protease Nexins; D051381:Rats; D017207:Rats, Sprague-Dawley; D011956:Receptors, Cell Surface; D012689:Sequence Homology, Nucleic Acid
chemical_list: D016564:Amyloid beta-Protein Precursor; D002352:Carrier Proteins; D058255:Protease Nexins; D011956:Receptors, Cell Surface; D003024:Clozapine