title: Proteomic alteration of mitochondrial aldehyde dehydrogenase 2 in sepsis regulated by heat shock response.
abstract: The present study was designed to investigate the proteomic alteration of hepatic mitochondria during sepsis and to explore the possible effects induced by heat shock treatment. Sepsis was induced by cecal ligation and puncture in Sprague-Dawley rats. Liver mitochondrial proteins were isolated and evaluated by 2-dimensional electrophoresis with broad pH-ranged (pH 3 - 10) immobile DryStrip and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The protein spots were visualized with silver stain and analyzed by Bio-2D software. Results showed that around 120 dominant spots could be separated and visualized distinctly by 2-dimensional electrophoresis analysis. Among them, three spots with the same molecular weight (56.4 kd), mitochondrial protein 1 (MP1), MP2, and MP3, were significantly altered in septic specimens. When analyzed by liquid chromatography-tandem mass spectrometry, the three spots all revealed to be an identical enzyme: aldehyde dehydrogenase 2 (ALDH2, EC 1.2.1.3). During sepsis, MP1 and MP2 were downregulated, whereas MP3 was upregulated concomitantly. Interestingly, heat shock treatment could reverse this phenomenon. Phosphoprotein staining showed that the degree of phosphorylation is higher in MP1 and MP2 than that in MP3. The enzyme activity assay showed that ALDH2 activity was downregulated in nonheated septic rats of 18 h after cecal ligation and puncture operation, and preserved in heated septic rats. The results of this study suggest that posttranslation modification, highly possible the phosphorylation, in ALDH2 may play a functional role in the pathogenesis of sepsis and provide a novel protective mechanism of heat shock treatment.
authors.affiliation: Department of Microbiology, Faculty of Medicine, College of Medicine, Kaohsiung Medical University, 100 Shih-Chuan 1st Road, Kaohsiung City, Taiwan.
authors.forename: Hsiang-Wen
authors.initials: HW
authors.lastname: Chen
authors.forename: Hung-Tien
authors.initials: HT
authors.lastname: Kuo
authors.forename: Long-Chih
authors.initials: LC
authors.lastname: Hwang
authors.forename: Mei-Fang
authors.initials: MF
authors.lastname: Kuo
authors.forename: Rei-Cheng
authors.initials: RC
authors.lastname: Yang
mesh_terms: D000444:Aldehyde Dehydrogenase / Q000235:genetics / Q000378:metabolism*; D000071396:Aldehyde Dehydrogenase, Mitochondrial; D000595:Amino Acid Sequence; D000818:Animals; D015153:Blotting, Western; D002853:Chromatography, Liquid; D015180:Electrophoresis, Gel, Two-Dimensional; D050884:HSP72 Heat-Shock Proteins / Q000378:metabolism; D018869:Heat-Shock Response / Q000502:physiology; D006358:Hot Temperature; D008297:Male; D008930:Mitochondria, Liver / Q000378:metabolism; D024101:Mitochondrial Proteins / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D010750:Phosphoproteins / Q000378:metabolism; D020543:Proteome / Q000032:analysis* / Q000235:genetics / Q000378:metabolism; D040901:Proteomics / Q000379:methods; D051381:Rats; D017207:Rats, Sprague-Dawley; D018805:Sepsis / Q000378:metabolism* / Q000503:physiopathology; D017386:Sequence Homology, Amino Acid; D053719:Tandem Mass Spectrometry
chemical_list: D050884:HSP72 Heat-Shock Proteins; D024101:Mitochondrial Proteins; D010750:Phosphoproteins; D020543:Proteome; D000444:Aldehyde Dehydrogenase; D000071396:Aldehyde Dehydrogenase, Mitochondrial; C505112:Aldh2 protein, rat