title: Expression of heat shock transcription factors and heat shock protein 72 in rat retina after intravitreal injection of low dose N-methyl-D-aspartate.
abstract: The heat shock response is a genetically well-ordered process for cell to generate heat shock protein (HSP). Various stressors can trigger the response through heat shock transcriptional factor (HSF) regulation. Recent studies demonstrated that preconditioning of N-methyl-d-aspartate (NMDA) at non-lethal levels has neuroprotective effects, but the exact mechanisms are unclear. We hypothesize that the protective mechanisms of NMDA preconditioning could involve HSP expression. To understand the regulatory mechanisms of HSP under stress, we examined the expression of Hsp72, HSF1 and HSF2 in the adult rat retina after intravitreal injection of NMDA. Retinal ganglion cell (RGC) counting with retrograde labeling showed that 8 nmol, but not 0.8 nmol, of intravitreal NMDA reduced RGC survival. Western blotting and immunohistochemistry showed that non-lethal (0.8 nmol) doses of NMDA induced a time-dependent expression of HSF1 and HSF2, and that the expression of HSF1 and HSF2 in the RGC layer peaked between 9 and 18 h after injection. Parallel to the increased HSF expression, immunohistochemistry and in situ hybridization demonstrated that Hsp72 mRNA and protein expression increased 9 and 12 h after non-lethal NMDA injection, respectively. Our findings suggest that the expression of HSF1 and HSF2 is associated with the Hsp72-related stress response.
authors.affiliation: Department of Ophthalmology, University of California Los Angeles, Los Angeles, CA 90075-7000, USA.
authors.forename: Jaehong
authors.initials: J
authors.lastname: Ahn
authors.forename: Natik
authors.initials: N
authors.lastname: Piri
authors.forename: Joseph
authors.initials: J
authors.lastname: Caprioli
authors.forename: Yasunari
authors.initials: Y
authors.lastname: Munemasa
authors.forename: Seok Hwan
authors.initials: SH
authors.lastname: Kim
authors.forename: Jacky M K
authors.initials: JM
authors.lastname: Kwong
mesh_terms: D000818:Animals; D002470:Cell Survival / Q000187:drug effects / Q000502:physiology; D019610:Cytoprotection / Q000187:drug effects / Q000502:physiology*; D004268:DNA-Binding Proteins / Q000187:drug effects / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D018690:Excitatory Amino Acid Agonists / Q000494:pharmacology; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology; D050884:HSP72 Heat-Shock Proteins / Q000187:drug effects / Q000378:metabolism*; D000076249:Heat Shock Transcription Factors; D006360:Heat-Shock Proteins / Q000187:drug effects / Q000378:metabolism; D018869:Heat-Shock Response / Q000187:drug effects / Q000502:physiology*; D007150:Immunohistochemistry; D008297:Male; D016202:N-Methylaspartate / Q000494:pharmacology; D018696:Neuroprotective Agents / Q000494:pharmacology; D012333:RNA, Messenger / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D012160:Retina / Q000187:drug effects / Q000378:metabolism* / Q000503:physiopathology; D012165:Retinal Ganglion Cells / Q000187:drug effects / Q000378:metabolism; D013312:Stress, Physiological / Q000139:chemically induced / Q000378:metabolism* / Q000503:physiopathology; D013997:Time Factors; D014157:Transcription Factors / Q000187:drug effects / Q000378:metabolism*; D015854:Up-Regulation / Q000187:drug effects / Q000502:physiology; D014822:Vitreous Body / Q000187:drug effects
chemical_list: D004268:DNA-Binding Proteins; D018690:Excitatory Amino Acid Agonists; C000619706:HSF1 protein, human; D050884:HSP72 Heat-Shock Proteins; D000076249:Heat Shock Transcription Factors; D006360:Heat-Shock Proteins; C000619709:Hsf1 protein, rat; D018696:Neuroprotective Agents; D012333:RNA, Messenger; D014157:Transcription Factors; C070389:HSF2 protein, human; D016202:N-Methylaspartate