Multiple-stressor effects in an apex predator: combined influence of pollutants and sea ice decline on lipid metabolism in polar bears

• Published in: Scientific Reports
• Main Authors: Tartu, Sabrina, Lille-Langøy, Roger, Størseth, Trond Røvik, Bourgeon, Sophie, Brunsvik, Anders, Goksøyr, Anders, Jenssen, Bjørn Munro, Polder, Anuschka, Thiemann, Gregory W., Torget, Vidar, Routti, Heli
• Format: Article in Journal/Newspaper
• Language: English
• Published: Nature Publishing Group 2017
• Subjects: Arctic; Norway; Svalbard; Sea ice; Ursus maritimus
• Online Access: http://hdl.handle.net/11250/2468494; https://doi.org/10.1038/s41598-017-16820-5

There is growing evidence from experimental and human epidemiological studies that many pollutants can disrupt lipid metabolism. In Arctic wildlife, the occurrence of such compounds could have serious consequences for seasonal feeders. We set out to study whether organohalogenated compounds (OHCs) could cause disruption of energy metabolism in female polar bears (Ursus maritimus) from Svalbard, Norway (n=112). We analyzed biomarkers of energy metabolism including the abundance profles of nine lipid-related genes, fatty acid (FA) synthesis and elongation indices in adipose tissue, and concentrations of lipid-related variables in plasma (cholesterol, high-density lipoprotein, triglycerides). Furthermore, the plasma metabolome and lipidome were characterized by low molecular weight metabolites and lipid fngerprinting, respectively. Polychlorinated biphenyls, chlordanes, brominated diphenyl ethers and perfuoroalkyl substances were signifcantly related to biomarkers involved in lipid accumulation, FA metabolism, insulin utilization, and cholesterol homeostasis. Moreover, the efects of pollutants were measurable at the metabolome and lipidome levels. Our results indicate that several OHCs afect lipid biosynthesis and catabolism in female polar bears. Furthermore, these efects were more pronounced when combined with reduced sea ice extent and thickness, suggesting that climatedriven sea ice decline and OHCs have synergistic negative efects on polar bears. publishedVersion © The Author(s) 2017. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.