title: PLG regulates hnRNP-L expression in the rat striatum and pre-frontal cortex: identification by ddPCR.
abstract: Central dopaminergic systems are implicated in schizophrenia and Parkinson's disease, and are known to be modulated by the endogenous tripeptide Pro-Leu-Gly-NH(2) (PLG or MIF-1, melanocyte-stimulating hormone release inhibiting factor-1). Differential display polymerase chain reaction (ddPCR) was utilized to identify genes that are regulated by protracted PLG treatment (20 mg/kg, i.p. for 28 days) in male Sprague-Dawley rats. A total of 2400 genes were screened and 3 down-regulated bands were identified in the PLG-treated samples. Sequencing analysis revealed a total of six unique cDNA species. One fragment possessed a high degree of homology with Mus musculus hnRNP-L (protein L) mRNA (GenBank #AB009392) (termed PRG1: PLG regulated gene 1). Elongation of the PRG1 cDNA, by RACE-PCR, provided an 835 bp sequence with 95% homology to AB009392 over a 743 bp span. Open reading frame analysis provided a putative amino acid sequence consistent with the identity of PRG1 as rat hnRNP-L. Northern hybridization experiments with PRG1 revealed a 2.3 kb mRNA species that was decreased by 65% in the PLG-treated tissue. Western blot analysis revealed significantly decreased hnRNP-L levels in the striatum and pre-frontal cortex (but not the nucleus accumbens) by 71 and 61%, respectively of PLG-treated animals. The identification of altered expression of hnRNP-L following PLG treatment provides insight into the long-term effects of PLG and may provide insight into its molecular mechanism of action.
authors.affiliation: Department of Pharmacology, Faculty of Medicine, Sir Charles Tupper Medical Building, Dalhousie University, Halifax, Nova Scotia, Canada B3H 4H7. mishrar@fhs.mcmaster.ca
authors.forename: Willard J
authors.initials: WJ
authors.lastname: Costain
authors.forename: Ram K
authors.initials: RK
authors.lastname: Mishra
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D015153:Blotting, Western; D003342:Corpus Striatum / Q000187:drug effects* / Q000378:metabolism; D018076:DNA, Complementary; D034664:Heterogeneous-Nuclear Ribonucleoprotein L / Q000235:genetics*; D009075:MSH Release-Inhibiting Hormone / Q000494:pharmacology*; D008297:Male; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D017397:Prefrontal Cortex / Q000187:drug effects* / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid
chemical_list: D018076:DNA, Complementary; D034664:Heterogeneous-Nuclear Ribonucleoprotein L; D009075:MSH Release-Inhibiting Hormone