title: Lipidomics and H2(18)O labeling techniques reveal increased remodeling of DHA-containing membrane phospholipids associated with abnormal locomotor responses in α-tocopherol deficient zebrafish (danio rerio) embryos.
abstract: We hypothesized that vitamin E (α-tocopherol) is required by the developing embryonic brain to prevent depletion of highly polyunsaturated fatty acids, especially docosahexaenoic acid (DHA, 22:6), the loss of which we predicted would underlie abnormal morphological and behavioral outcomes. Therefore, we fed adult 5D zebrafish (Danio rerio) defined diets without (E-) or with added α-tocopherol (E+, 500mg RRR-α-tocopheryl acetate/kg diet) for a minimum of 80 days, and then spawned them to obtain E- and E+ embryos. The E- compared with E+ embryos were 82% less responsive (p<0.01) to a light/dark stimulus at 96h post-fertilization (hpf), demonstrating impaired locomotor behavior, even in the absence of gross morphological defects. Evaluation of phospholipid (PL) and lysophospholipid (lyso-PL) composition using untargeted lipidomics in E- compared with E+ embryos at 24, 48, 72, and 120hpf showed that four PLs and three lyso-PLs containing docosahexaenoic acid (DHA), including lysophosphatidylcholine (LPC 22:6, required for transport of DHA into the brain, p<0.001), were at lower concentrations in E- at all time-points. Additionally, H2(18)O labeling experiments revealed enhanced turnover of LPC 22:6 (p<0.001) and three other DHA-containing PLs in the E- compared with the E+ embryos, suggesting that increased membrane remodeling is a result of PL depletion. Together, these data indicate that α-tocopherol deficiency in the zebrafish embryo causes the specific depletion and increased turnover of DHA-containing PL and lyso-PLs, which may compromise DHA delivery to the brain and thereby contribute to the functional impairments observed in E- embryos.
authors.affiliation: Linus Pauling Institute, Oregon State University, Corvallis, OR 97331, USA; College of Public Health and Human Sciences, Oregon State University, Corvallis, OR 97331, USA.
authors.forename: Melissa Q
authors.initials: MQ
authors.lastname: McDougall
authors.affiliation: Linus Pauling Institute, Oregon State University, Corvallis, OR 97331, USA.
authors.forename: Jaewoo
authors.initials: J
authors.lastname: Choi
authors.affiliation: Linus Pauling Institute, Oregon State University, Corvallis, OR 97331, USA; College of Pharmacy, Oregon State University, Corvallis, OR 97331, USA; Environmental Health Sciences Center, Oregon State University, Corvallis, OR 97331, USA.
authors.forename: Jan F
authors.initials: JF
authors.lastname: Stevens
authors.affiliation: Sinnhuber Aquatic Research Laboratory, Oregon State University, Corvallis, OR 97331, USA; Environmental and Molecular Toxicology, Oregon State University, Corvallis, OR 97331, USA; Environmental Health Sciences Center, Oregon State University, Corvallis, OR 97331, USA.
authors.forename: Lisa
authors.initials: L
authors.lastname: Truong
authors.affiliation: Sinnhuber Aquatic Research Laboratory, Oregon State University, Corvallis, OR 97331, USA; Environmental and Molecular Toxicology, Oregon State University, Corvallis, OR 97331, USA; Environmental Health Sciences Center, Oregon State University, Corvallis, OR 97331, USA.
authors.forename: Robert L
authors.initials: RL
authors.lastname: Tanguay
authors.affiliation: Linus Pauling Institute, Oregon State University, Corvallis, OR 97331, USA; College of Public Health and Human Sciences, Oregon State University, Corvallis, OR 97331, USA; Environmental Health Sciences Center, Oregon State University, Corvallis, OR 97331, USA. Electronic address: maret.traber@oregonstate.edu.
authors.forename: Maret G
authors.initials: MG
authors.lastname: Traber
mesh_terms: D000818:Animals; D001522:Behavior, Animal; D002462:Cell Membrane / Q000378:metabolism; D004281:Docosahexaenoic Acids / Q000378:metabolism*; D004625:Embryo, Nonmammalian; D050356:Lipid Metabolism; D008246:Lysophospholipids / Q000378:metabolism; D055442:Metabolome; D055432:Metabolomics / Q000379:methods; D010641:Phenotype; D010743:Phospholipids / Q000378:metabolism*; D014811:Vitamin E Deficiency / Q000378:metabolism*; D015027:Zebrafish / Q000378:metabolism*; D024502:alpha-Tocopherol / Q000378:metabolism*
chemical_list: D008246:Lysophospholipids; D010743:Phospholipids; D004281:Docosahexaenoic Acids; D024502:alpha-Tocopherol
keywords: Brain; Development; Docosahexaenoic acid; H(2)(18)O; Mass spectrometry; Peroxidation; Phospholipids; Vitamin E