Aortic Injury Induced by Benzo(a)pyrene and Atherogenic Diet Increased Hepatic FGF21 Expression in C57BL/6J Mice.

BACKGROUND

Benzo(a)pyrene (BaP), an environmental toxicant and endocrine disruptor, has been shown to exacerbate atherosclerosis when combined with a high-fat diet. Fibroblast Growth Factor-21 (FGF21), a novel hormone with anti-atherosclerotic properties, is associated with the presence of atherosclerosis and reduces plaque formation in experimental animals.

OBJECTIVES

The present study aimed to investigate the chronic effect of BaP injection on hepatic FGF21 expression, as an anti-atherosclerotic hormone, in mice fed with or without an atherogenic diet (AtD).

METHODS

Eighteen C57BL/6J male mice (6 weeks) were randomly divided into six groups based on the dosage and diet. Blood samples were collected, and serum cholesterol, triglyceride, HDL-C, LDL-C, and glucose levels were measured. FGF21 expression was assessed by quantitative real-time PCR. Atherosclerotic lesions in mice were studied with Oil Red O (ORO) staining.

RESULTS

Benzo(a)pyrene causes a significant increase in liver FGF21 expression in a dose-dependent manner, and BaP co-exposure with AtD leads to a further increase in FGF21 expression. Additionally, the addition of BaP to AtD significantly increased the serum glucose, cholesterol, and LDL-C levels and accelerated the formation of atherosclerotic lesions. Besides, our findings showed that there is a significant positive correlation between FGF21 expression and glucose, cholesterol, LDL-C, and ORO-positive areas.

CONCLUSIONS

Our findings revealed that BaP increases the expression of endogenous FGF21 in treated animals as a compensatory response to protect the heart from atherosclerosis induced by BaP and AtD.