Characterization of POP mixture redistribution and identification of their molecular signature in xenografted fat mice

Persistent organic pollutants (POPs) are associated with many adverse health effects in humans, including cancers, immune, reproductive, neurological disorders and metabolic diseases. These chemicals are known to accumulate in fatty tissues, from which they can be released in other tissue compartments of living organisms, in particular, upon weight loss. This dynamic distribution of POPs remains, however poorly investigated. In this study, a xenografted POP-contaminated adipose tissue (AT) model was used to assess 1) their concentrations in the ATs, the liver and the brain and 2) their associated effects by transcriptomics, metabolomics and lipidomics approaches. In the ATs, the liver and the brain of mice grafted with POP-contaminated fat pad, most of POPs were detected 3 days and 21 days after the graft with the highest concentrations in the ATs and the lowest concentrations in the brain. Conversely, per- and polyfluoroalkyl substances presented a distinct profile as they persist in the liver but not in the ATs or in the brain. In the AT of POP-exposed mice, the most dysregulated pathways were related to mitochondrial functions, endobiotic (carbohydrate, lipid, amino acid) and xenobiotic metabolism and inflammatory response. In the liver of grafted mice, many pathways related to mitochondrial functions and metabolism were dysregulated. These results support that realistic mixture of POPs that accumulate in AT and liver induces a systemic metabolic dysfunction which may represent the mechanisms by which the POPs can promote metabolic diseases such as obesity, type 2 diabetes and cardiovascular diseases.