| Summary: | For a long time, adipose tissue was considered an inert energy storage site. About twenty years ago, its endocrine function was discovered. Since then, studies have highlighted the involvement of this organ in major processes such as energy homeostasis, inflammation and immunity. Adipose tissue is also a target for anthropogenic stressors such as persistent organic pollutants (POPs) and chronic stress-response induced by repeated stress exposure. To date, little is known regarding the impact of combined stressors on adipose tissue function. The present work aimed at investigating the impact of multiple stressors to which adipose tissue is exposed through an innovative ex vivo approach of precision-cut adipose tissue slices (PCATS). Northern elephant seal pups were used as a model for marine mammals. Exposure of PCATS to stress hormones epinephrine and cortisol regulated key lipases and increased lipolysis. PCBs present in PCATS were mainly retained within the tissue. Their limited mobilization depended on their degree of lipophilicity. Leptin was downregulated by epinephrine while cortisol offset this effect. A subsequent transcriptomic study on combined stress hormones, a mixture of POPs and high-pressure cycles showed alterations of genes related to key biological processes such as inflammation and autophagy in PCATS. We also highlighted potential marker genes of stress status in blubber. In addition to the NES model, PCATS were also successfully developed on porcine subcutaneous adipose tissue as a model for human health. Exposure of porcine PCATS to a mixture of POPs decreased basal and epinephrine-induced lipolysis in a dose-dependent way. This work brings new insights in the interactive alterations caused by multiple stressors on adipose tissue. The PCATS method opens the way for additional ecotoxicological research in wildlife and studies in human health. (AGRO - Sciences agronomiques et ingénierie biologique) -- UCL, 2024
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