Chronic exposure to low doses of ionizing radiation impacts the processing of glycoprotein N-linked glycans in Medaka (<i>Oryzias latipes</i>)
Creators: name: Yeni Natalia C. Perez-Gelvez
name: Shem Unger
name: Kurz, Simone
name: Rosenbalm, Katelyn
name: Wright, William Matthew
name: Rhodes, Olin E.
name: Tiemeyer, Michael
name: Bergmann, Carl W.
Publisher: name: Taylor & Francis
Year: 2020
Subjects: subject: Biophysics
subject: Biochemistry
subject: Genetics
subject: FOS: Biological sciences
subject: FOS: Biological sciences
subject: Biotechnology
subject: 59999 Environmental Sciences not elsewhere classified
subject: FOS: Earth and related environmental sciences
subject: FOS: Earth and related environmental sciences
subject: 39999 Chemical Sciences not elsewhere classified
subject: FOS: Chemical sciences
subject: FOS: Chemical sciences
subject: Ecology
subject: 69999 Biological Sciences not elsewhere classified
subject: 110309 Infectious Diseases
subject: FOS: Health sciences
subject: FOS: Health sciences

description: Ionizing radiation is found naturally in the environment; we receive low doses regularly from space, soil, rocks, water, air, and vegetation. While a low dose of IR may have beneficial applications, especially in medicine, it also has the potential to cause detrimental long-term health effects. Alterations in phenotypes and biomolecules after exposure to high levels of IR are well understood and biomarkers exist to detect these kinds of exposures. On the other hand, alterations following exposure to low levels have been difficult to identify and quantify. Glycoprotein glycosylation is a highly regulated post-translational process that is critical to proper protein folding and is vital to cell-cell communication. Glycosylation is likely sensitive to changes in an organism’s macro-environment or to changes in cellular micro-environments. Few studies have analyzed whether glycoprotein glycosylation is altered in response to high level radiation exposure and none have analyzed the impact of chronic exposure to low doses of IR (LoDIR). In this study, we investigated whether accumulated low doses of IR affect the structural diversity and biosynthetic processing of N-linked glycoprotein glycans using Medaka fish (<i>Oryzias latipes</i>) as a model organism. State-of-the-art methods in radiation exposure and glycan analysis were applied to study chronic low dose exposure for 190 days at three different low rates of gamma irradiation (2.25, 21.01 and 204.3 mGy/day) in wild-type adult Medaka. The fish were dissected and tissue N-glycans were analyzed following enzymatic release from extracted proteins. Mass spectrometric analyses of the glycoprotein N-linked glycans harvested from control and irradiated fish demonstrated that N-linked glycan profiles are dominated by complex type N-glycans modified with terminal sialic acid and core fucose. Our results indicate that fucosylation and sialylation of N-linked glycoprotein glycans are affected by LoDIR and that a subset of N-glycans are involved in the organismal response to environmentally relevant radiological exposure. Our results provide the first indication that the glycome, defined as the complete set of glycoconjugate glycans expressed in an organism, can be interrogated for biomarkers that report the impact of chronic exposure to environmental stressors, such as low-level IR.