Effects of chronic exposure to low levels of IR on Medaka (Oryzias latipes): a proteomic and bioinformatic approach

Abstract

Purpose

Chronic exposure to ionizing radiation (IR) at low doses (<100 mGy) has been insufficiently studied to understand fully the risk to health. Relatively little knowledge exists regarding how species and healthy tissues respond at the protein level to chronic exposure to low doses of IR, and mass spectrometric-based profiling of protein expression is a powerful tool for studying changes in protein abundance.

Materials and methods

SDS gel electrophoresis, LC-MS/MS mass spectrometry-based approaches and bioinformatic data analytics were used to detect proteomic changes following chronic exposure to moderate/low doses of radiation in adults and normally developed Medaka fish (Oryzias latipes).

Results

Significant variations in the abundance of proteins involved in thyroid hormone signaling and lipid metabolism were detected, which could be related to the gonadal regression phenotype observed after 21.04 mGy and 204.3 mGy/day exposure. The global proteomic change was towards overexpression of proteins in muscle and skin, while the opposite effect was observed in internal organs.

Conclusion

The present study provides information on the impacts of biologically relevant low doses of IR, which will be useful in future research for the identification of potential biomarkers of IR exposure and allow for a better assessment of radiation biosafety regulations.

Keywords:

• Proteomics
• low dose ionizing radiation
• Medaka

Acknowledgments

We thank the LoDiF facility at the SREL for help to conduct the exposure for this experiment, M.S Brent Weatherly for his guidance on ProteoIQ software, Dr. Oscar Flórez-Vargas, and MSc. Maria Luisa Muller Theissen for their guidance on the use of R software. The authors thank the students that assisted in the laboratory during this research: Olivia Gavriella Mendel, Tova Asher, Daniel Singer, and William Matthew Wright for their valuable help.

Disclosure statement

This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof.

Additional information

Funding

This research was supported by the Award Number DE-EM0004391 to the University of Georgia Research Foundation from the U.S. Department of Energy.

Notes on contributors

Yeni Natalia C. Perez-Gelvez

Yeni Natalia C. Perez-Gelvez is Postdoctoral Research Associate at the Complex Carbohydrate Research Center at the University of Georgia. She completed a Bachelor of Microbiology at The University of Pamplona, Colombia, Master’s in biotechnology at The CIBA-IPN, Mexico and PhD in Biochemistry and Molecular Biology at UGA. Natalia studies the effects of chronic exposure to low-dose of IR at the glycomic and proteomic level.

Alvin C. Camus

Alvin Camus is a DVM, PhD, Certified Fish Pathologist, and Professor in the Department of Pathology, College of Veterinary Medicine at the University of Georgia where he focuses on fish health and disease diagnostics as well as a resident training program in aquatic animal pathology in partnership with the Georgia Aquarium, Atlanta, GA. He has served previously as a pathologist for the Louisiana Aquatic Animal Disease Diagnostic Laboratory and as Director of the Aquatic Diagnostic Laboratory, Thad Cochran National Warmwater Aquaculture Center in Stoneville, MS. Research interests include pathogen discovery, myxozoan parasitism, and diseases of elasmobranch fish.

Robert Bridger

Robert Bridger is a Laboratory Professional at the Complex Carbohydrate Research Center at the University of Georgia. He has been working in the laboratory of Dr. Wells for over ten years with a primary focus of mass spectrometry-based research. He performs maintenance, calibration, and sample analysis for many collaborative projects across UGA and beyond. He is also a glycoproteomics instructor for the training course held by Dr. Wells and Dr. Tiemeyer as part of the Thermo Fisher^© Center of Excellence for Glycomics and Glycoproteomics.

Lance Wells

Lance Wells is a Georgia Research Alliance Distinguished Investigator, Director of Integrated Life Sciences, and Professor of Biochemistry & Molecular Biology in the Complex Carbohydrate Research Center at the University of Georgia. He is also the Co-Director of the Thermo Fisher^© Center of Excellence for Glycomics and Glycoproteomics. Wells has authored over 150 publications addressing primarily the role of protein glycosylation in human disease states.

Olin E. Rhodes

Olin E. Rhodes, Jr. is the Director of the University of Georgia’s Savannah River Ecology Laboratory and a Georgia Athletic Association Professor of Applied Ecology in the Odum School of Ecology at the University of Georgia. His previous positions include 15 years as a Professor and Center Director at Purdue University and two years as the Assistant Director of USDA’s National Wildlife Research Center in Fort Collins, Colorado. Rhodes has authored over 220 publications addressing the conservation and management of wildlife. He holds a doctorate in wildlife science. His interests include wildlife ecology, human wildlife conflicts, and applied wildlife genetics.

Carl W. Bergmann

Carl W. Bergmann is the Associate Vice President for Research at University of Georgia, where he is responsible for UGA Core Research Laboratories and Research Facilities. Carl received his Ph.D. in Organic Chemistry from the Ohio State University and has been a member of UGA’s Complex Carbohydrate Research Center since 1986 where he is currently Associate Director. His research has traditionally focused on the biochemistry of acidic polysaccharides of plant and animal origin. During his role as Director of the Savannah River Ecology Laboratory (2007–2011), he became interested in research related to Low-Dose Radiation exposure and how glycans responds to chronic exposure.