title: Glucose induces sensitivity to oxygen deprivation and modulates insulin/IGF-1 signaling and lipid biosynthesis in Caenorhabditis elegans.
abstract: Diet is a central environmental factor that contributes to the phenotype and physiology of individuals. At the root of many human health issues is the excess of calorie intake relative to calorie expenditure. For example, the increasing amount of dietary sugars in the human diet is contributing to the rise of obesity and type 2 diabetes. Individuals with obesity and type 2 diabetes have compromised oxygen delivery, and thus it is of interest to investigate the impact a high-sugar diet has on oxygen deprivation responses. By utilizing the Caenorhabditis elegans genetic model system, which is anoxia tolerant, we determined that a glucose-supplemented diet negatively impacts responses to anoxia and that the insulin-like signaling pathway, through fatty acid and ceramide synthesis, modulates anoxia survival. Additionally, a glucose-supplemented diet alters lipid localization and initiates a positive chemotaxis response. Use of RNA-sequencing analysis to compare gene expression responses in animals fed either a standard or glucose-supplemented diet revealed that glucose impacts the expression of genes involved with multiple cellular processes including lipid and carbohydrate metabolism, stress responses, cell division, and extracellular functions. Several of the genes we identified show homology to human genes that are differentially regulated in response to obesity or type 2 diabetes, suggesting that there may be conserved gene expression responses between C. elegans fed a glucose-supplemented diet and a diabetic and/or obesity state observed in humans. These findings support the utility of the C. elegans model for understanding the molecular mechanisms regulating dietary-induced metabolic diseases.
authors.affiliation: Department of Biological Sciences, University of North Texas, Denton, Texas 76203.
authors.forename: Anastacia M
authors.initials: AM
authors.lastname: Garcia
authors.affiliation: Department of Biological Sciences, University of North Texas, Denton, Texas 76203.
authors.forename: Mary L
authors.initials: ML
authors.lastname: Ladage
authors.affiliation: Department of Biological Sciences, University of North Texas, Denton, Texas 76203.
authors.forename: Dennis R
authors.initials: DR
authors.lastname: Dumesnil
authors.affiliation: Department of Biological Sciences, University of North Texas, Denton, Texas 76203.
authors.forename: Khadiza
authors.initials: K
authors.lastname: Zaman
authors.affiliation: Department of Biological Sciences, University of North Texas, Denton, Texas 76203.
authors.forename: Vladimir
authors.initials: V
authors.lastname: Shulaev
authors.affiliation: Department of Biological Sciences, University of North Texas, Denton, Texas 76203 Department of Mathematics, University of North Texas, Denton Texas 76203 pamela.padilla@unt.edu Rajeev.Azad@unt.edu.
authors.forename: Rajeev K
authors.initials: RK
authors.lastname: Azad
authors.affiliation: Department of Biological Sciences, University of North Texas, Denton, Texas 76203 pamela.padilla@unt.edu Rajeev.Azad@unt.edu.
authors.forename: Pamela A
authors.identifier: http://orcid.org/0000-0001-8532-0254
authors.initials: PA
authors.lastname: Padilla
mesh_terms: D000818:Animals; D017173:Caenorhabditis elegans / Q000235:genetics / Q000378:metabolism*; D050260:Carbohydrate Metabolism / Q000235:genetics; D002518:Ceramides / Q000096:biosynthesis; D004032:Diet; D005227:Fatty Acids / Q000096:biosynthesis; D020869:Gene Expression Profiling; D005947:Glucose / Q000008:administration & dosage / Q000378:metabolism*; D000860:Hypoxia / Q000235:genetics / Q000378:metabolism*; D007328:Insulin / Q000378:metabolism*; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D050356:Lipid Metabolism / Q000235:genetics*; D015398:Signal Transduction
chemical_list: D002518:Ceramides; D005227:Fatty Acids; D007328:Insulin; D007334:Insulin-Like Growth Factor I; D005947:Glucose
keywords: C. elegans; gene expression; insulin signaling; oxygen deprivation; sugar diet