Alzheimer's Disease Affects Severity of Asthma Through Methylation Control of Foxp3 Promoter.

Recent studies suggest that severity of asthma can be modulated by neuropsychiatric conditions, while the underlying mechanisms are not clear. Here, we used ovalbumin (OVA) to induce asthma in APP/PS1 mice, a mouse model of Alzheimer's disease (AD), or in their wildtype control C57BL/6J mice. We found that all hallmarks of asthma by OVA were significantly attenuated in APP/PS1 mice, compared to age- and gender-matched C57BL/6J mice. Interestingly, significantly higher number of regulatory T cells (Treg) was detected in the APP/PS1 mouse lung, compared to those in the C57BL/6J mouse lung. Since Foxp3 is crucial for differentiation of naive T cells into Treg and is the most important marker for Treg, we examined the Foxp3 levels in the T cells from the lung of these mice. We found that the Foxp3 levels in the APP/PS1 mouse lung were significantly higher than those in the C57BL/6J mouse lung, likely resulting from reduced Foxp3 promoter methylation. Thus, our study suggests that AD may affect severity of asthma through methylation control of Foxp3 promoter in T cells.