title: Zinc and DHA have opposing effects on the expression levels of histones H3 and H4 in human neuronal cells.
abstract: Zn and DHA have putative neuroprotective effects and these two essential nutrients are known to interact biochemically. We aimed to identify novel protein candidates that are differentially expressed in human neuronal cell line M17 in response to Zn and DHA that would explain the molecular basis of this interaction. Two-dimensional gel electrophoresis and MS were applied to identify major protein expression changes in the protein lysates of human Ml7 neuronal cells that had been grown in the presence and absence of Zn and DHA. Proteomic findings were further investigated using Western immunoblot and real-time PCR analyses. Four protein spots, which had significant differential expression, were identified and selected for in-gel trypsin digestion followed by matrix-assisted laser desorption ionisation MS analysis. The resultant peptide mass fingerprint for each spot allowed their respective identities to be deduced. Two human histone variants H3 and H4 were identified. Both H3 and H4 were downregulated by Zn in the absence of DHA (Zn effect) and upregulated by DHA (DHA effect) in the presence of Zn (physiological condition). These proteomic findings were further supported by Western immunoblot and real-time PCR analyses using H3- and H4-specific monoclonal antibodies and oligonucleotide primers, respectively. We propose that dietary Zn and DHA cause a global effect on gene expression, which is mediated by histones. Such novel information provides possible clues to the molecular basis of neuroprotection by Zn and DHA that may contribute to the future treatment, prevention and management of neurodegenerative diseases such as Alzheimer's disease.
authors.affiliation: Faculty of Science and Technology, School of Life and Environmental Sciences, Deakin University, 221 Burwood Highway, Burwood, Vic 3125, Australia. cenk.suphioglu@deakin.edu.au
authors.forename: Cenk
authors.initials: C
authors.lastname: Suphioglu
authors.forename: Nadia
authors.initials: N
authors.lastname: Sadli
authors.forename: Damon
authors.initials: D
authors.lastname: Coonan
authors.forename: Loveleen
authors.initials: L
authors.lastname: Kumar
authors.forename: Damitha
authors.initials: D
authors.lastname: De Mel
authors.forename: Jessica
authors.initials: J
authors.lastname: Lesheim
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Sinclair
authors.forename: Leigh
authors.initials: L
authors.lastname: Ackland
mesh_terms: D000199:Actins / Q000235:genetics; D045744:Cell Line, Tumor; D017931:DNA Primers; D004281:Docosahexaenoic Acids / Q000494:pharmacology*; D005786:Gene Expression Regulation / Q000187:drug effects; D015972:Gene Expression Regulation, Neoplastic; D006657:Histones / Q000235:genetics*; D006801:Humans; D009447:Neuroblastoma / Q000378:metabolism; D009474:Neurons / Q000187:drug effects / Q000378:metabolism; D016133:Polymerase Chain Reaction; D020543:Proteome / Q000187:drug effects / Q000235:genetics; D015032:Zinc / Q000494:pharmacology*
chemical_list: D000199:Actins; D017931:DNA Primers; D006657:Histones; D020543:Proteome; D004281:Docosahexaenoic Acids; D015032:Zinc