Objective: To study the effects of bisphenol A( BPA) on inflammation and Th17 cells in adipose tissue of high-fat fed mice.
Methods: 4-week-old male C57 BL /6mice were fed on high fat diet( HFD) and were administered 10, 100 and 1000 nmol / L BPA by drinking water. The normal diet( ND) and HFD control groups were set as well. Body weight of mice was recorded weekly. Mice were sacrificed at eighth and sixteenth week and epididymal fat pad was obtained. Hematoxylin-eosin( HE) staining was used to observe the cells morphological changes and inflammation in epididymal adipose tissue. Enzyme linked immunosorbent assay( ELISA) was used to detect TNF-α level in epididymal adipose tissue. Flow cytometry( FCM) was used to detect the proportion of Th17 cells in epididymal fat pad stromal vascular fractions( SVF). Immunohistochemistry( IHC) was used to detect the expression of IL-17 in epididymal adipose tissue.
Results: Compared with ND control groups, HFD increased body weight of mice, enhanced theinfiltration of inflammatory cells and the expression of TNF-α in adipose tissue. Also, the proportion of Th17 cells and the expression of IL-17 in adipose tissue were elevated. Compared with HFD control groups, BPA exposure enhanced the infiltration of inflammatory cells and the expression of TNF-α in adipose tissue. Also, the proportion of Th17 cells and the expression of IL-17 in adipose tissue were elevated in a dose-dependent way. And the effects at sixteenth week was more obvious than that at eighth week.
Conclusion: BPA exposure can promote inflammation in adipose tissue of high-fat fed mice and elevate the proportion of Th17 cells and the expression of IL-17. Th17 cells may play an important role in the effects BPA on adipose tissue inflammation.
Keywords: IL-17; Th17 cells; bisphenol A; inflammation; obesity.