Exposure to environmental chemicals can perturb an individual's metabolic set point, especially during critical periods of development, and as a result increase his or her propensity towards obesity that is manifested later in life and possibly in successive generations. We hypothesized that benzyl butyl phthalate (BBP), a widespread endocrine disruptor, may impair one important epigenetic regulator, sirtuin, in mesenchymal stem cells and induce adipogenesis. Our results showed that gene expression of two well-known adipogenic markers, aP2 and PPARγ, were significantly increased from day 2 to day 8 under 50μM BBP exposure when compared to control in C3H10T1/2 stem cells (p<0.05) and induced adipogenesis. Sirt1 gene expression was also significantly decreased at day 2, 4, 6, and 8 (p<0.05). However, Sirt7 gene expression was decreased only at day 2 and 8 (p<0.05) while other sirtuin transcriptional levels remained unaltered throughout. Furthermore, Sirt1 and Sirt3 protein expression was decreased (p<0.05) and overall protein hyperacetylation was observed at day 8. Furthermore, FOXO1 and β-catenin, Sirt1 targets and adipogenesis regulators, were hyperacetylated at day 8. PGC1α, NRF1, NRF2, and Tfam, were also significantly decreased (p<0.05). In conclusion, our study suggests for the first time that BBP, a potential epigenetic disruptor, can lead to increased adipogenesis and metabolic dysregulation by impairing vital epigenetic regulators.
Toxicology Abstracts; BBP Benzyl butyl phthalate; PGC1 alpha Peroxisome proliferator-activated receptor gamma coactivator 1 alpha; NRF1 Nuclear respiratory factor 1; NRF2 Nuclear respiratory factor 2; Tfam Mitochondrial transcription factor A; FOXO1 Forkhead box protein O1; Sirtuins; Benzyl butyl phthalate (BBP); Mesenchymal stem cell; Adipogenesis; Hyperacetylation; Endocrine disruptor; Endocrine disruptors; Obesity; Plasticizers; Butyl phthalate; Transcription; Mesenchyme; catenin; Gene expression; SIRT1 protein; epigenetics; FOXO1 protein; Stem cells; Peroxisome proliferator-activated receptors; Critical period; Differentiation; X 24350:Industrial Chemicals