Mathews, Jessica

Background: Myocarditis is an inflammatory heart disease caused by viral infections that can lead to heart failure, and occurs more often in men than women. Since animal studies have shown that myocarditis is influenced by sex hormones, we hypothesized that endocrine disruptors, which interfere with natural hormones, may play a role in the progression of the disease. The human population is exposed to the endocrine disruptor bisphenol A (BPA) from plastics, such as water bottles and plastic food containers. Methods: Male and female adult BALB/c mice were housed in plastic versus glass caging, or exposed to BPA in drinking water versus control water. Myocarditis was induced with coxsackievirus B3 on day 0, and the endpoints were assessed on day 10 post infection. Results: We found that male BALB/c mice that were exposed to plastic caging had increased myocarditis due to complement activation and elevated numbers of macrophages and neutrophils, whereas females had elevated mast cell activation and fibrosis. Conclusions: These findings show that housing mice in traditional plastic caging increases viral myocarditis in males and females, but using sex-specific immune mechanisms.

An estimated 1 billion people worldwide have deficient or insufficient levels of vitamin D (VitD). Considerable evidence indicates that VitD deficiency is associated with an increased risk of autoimmune and cardiovascular disease (CVD), yet it remains unclear whether low VitD is simply a biomarker or has a true pathologic role. In this study we examined how sex differences in VitD influences various CVDs. We found that patients with CVD had significantly lower VitD than healthy controls (no ICD9/10 codes). In myocarditis patients low VitD correlated to poor ejection fraction (EF) in women with myocarditis (p=0.02), but high VitD correlated with low EF in men (p=0.04). In VDR knockout mice we found that VDR decreased myocarditis in females (p=2E-8) but increased inflammation in males (p=0.03) with an increase in total immune cells (p=0.02), CD3, CD4 and CD8 T cells (p=0.04), and the inflammasome in females. VDR altered Treg (p=0.04), mast cells (p=0.04) and cytokine profiles in males. Additionally, sera VitD levels were significantly higher in WT male mice with myocarditis compared to females. Our findings in VDR mice indicate that VitD/VDR reduces myocarditis in females, but increases disease in males. These data suggest that VitD sufficiency may increase inflammation in men, while VitD deficiency may make disease worse in women. These findings suggest that Vitamin D may have a role in the pathogenesis of inflammatory and cardiovascular disease.