Cellular and Molecular Physiology Commons^™

Metabolic Transitions In Embryos Of Artemia Franciscana: Regulation And Consequences For Oxidative Stress, Daniel Anthony Arabie

LSU Doctoral Dissertations

Embryos of Artemia franciscana survive harsh conditions in diapause and anoxia-induced quiescence for years by undergoing deep metabolic transitions. I investigated the relationship between phosphorylation of pyruvate dehydrogenase (PDH) and carbon flux to the tricarboxylic acid (TCA) cycle during metabolic depression. The difference in catalytic activity of the PDH complex (PDC) in maximally phosphorylated and dephosphorylated samples was 16.5-fold. Western blot analysis confirmed the changes in phosphorylation of PDH. Analysis of PDH expression in diapause and post-diapause embryos via phospho-PDH showed no significant differences. Investigation of post-diapause embryos under anoxia showed that phosphorylation of PDH decreased and activated the enzyme. …

Effect Of Oxygen-Limiting Tidal Conditions On Muscle Metabolism And Structure In The Giant Acorn Barnacle, Balanus Nubilus, Katie O. Grady

Master's Theses

Crustacean muscle fibers are some of the largest cells in the animal kingdom, with fiber diameters in the giant acorn barnacle (Balanus nubilus) exceeding 3 mm. Sessile animals with extreme muscle sizes and that live in the hypoxia-inducing intertidal zone – like B. nubilus – represent ideal models for probing the effects of oxygen limitation on muscle cells. We investigated changes in metabolism and structure of B. nubilus muscle in response to: normoxic immersion, anoxic immersion, or air emersion, for acute (6h) or chronic (6h exposures twice daily for 2wks) time periods. Following exposure, we immediately measured hemolymph …

The Proteomic Response Of Gill Tissue In Tidally And Subtidally-Acclimated California Mussels, Mytilus Californianus, To Acute Emersion-Induced Anoxia, Aubrie N. Fowler, Lars Tomanek

Master's Theses

Intertidal mussels regularly experience emersion-induced anoxia, in contrast to normoxic conditions experienced during submersion. We therefore hypothesized that acclimation to a tidal rhythm, as opposed to a rhythm of constant submersion, preconditions the proteome of the California mussel, Mytilus californianus, to respond differently to emersion-induced anoxia. Following acclimation, mussels either continued to receive the acclimation conditions (control) or were exposed to 100% nitrogengas (anoxia) during aerial emersion. We collected gill tissue for subsequent analysis of protein abundance with 2D gel electrophoresis and protein identification with tandem mass spectrometry. Relative to subtidally-acclimated mussels, tidally-acclimated mussels showed a greater propensity to …

Long-Term Survival Of Anoxia Despite Rapid Atp Decline In Embryos Of The Annual Killifish Austrofundulus Limnaeus, Jason E. Podrabsky, Michael A. Menze, Steven C. Hand

Faculty Research & Creative Activity

Embryos of the annual killifish Austrofundulus limnaeus can survive for months in the complete absence of oxygen. Survival of anoxia is associated with entry into a state of metabolic dormancy known as diapause. However, extreme tolerance of anoxia is retained for several days of post-diapause development. Rates of heat dissipation in diapause II and 4 days post-diapause II embryos were measured under aerobic conditions and during the transition into anoxia. Phosphorylated adenylate compounds were quantified in embryos during entry into anoxia and after 12 hr of aerobic recovery. Rates of heat dissipation were not affected by exposure to anoxia in …

Long-Term Survival Of Anoxia Despite Rapid Atp Decline In Embryos Of The Annual Killifish Austrofundulus Limnaeus., Jason Podrabsky, Michael Menze, Steven Hand

Faculty and Staff Scholarship

Embryos of the annual killifish Austrofundulus limnaeus can survive for months in the complete absence of oxygen. Survival of anoxia is associated with entry into a state of metabolic dormancy known as diapause. However, extreme tolerance of anoxia is retained for several days of post-diapause development. Rates of heat dissipation in diapause II and 4 days post-diapause II embryos were measured under aerobic conditions and during the transition into anoxia. Phosphorylated adenylate compounds were quantified in embryos during entry into anoxia and after 12 hr of aerobic recovery. Rates of heat dissipation were not affected by exposure to anoxia in …

Aberrant Promoter Cpg Methylation Is A Mechanism For Impaired Phd3 Expression In A Diverse Set Of Malignant Cells., Trenton L. Place, Matthew P. Fitzgerald, Sujatha Venkataraman, Sabine U. Vorrink, Adam J. Case, Melissa L.T. Teoh, Frederick E. Domann

Journal Articles: Cellular & Integrative Physiology

BACKGROUND: The prolyl-hydroxylase domain family of enzymes (PHD1-3) plays an important role in the cellular response to hypoxia by negatively regulating HIF-α proteins. Disruption of this process can lead to up-regulation of factors that promote tumorigenesis. We observed decreased basal expression of PHD3 in prostate cancer tissue and tumor cell lines representing diverse tissues of origin. Furthermore, some cancer lines displayed a failure of PHD3 mRNA induction when introduced to a hypoxic environment. This study explores the mechanism by which malignancies neither basally express PHD3 nor induce PHD3 under hypoxic conditions.

METHODOLOGY/PRINCIPAL FINDINGS: Using bisulfite sequencing and methylated DNA enrichment …