Acetylcholinesterase Inhibition Reverses Age-Related Pulmonary Decline and Increases Bronchus-Associated Lymphoid Tissue Formation in Aged Mice.

Age-related chronic, low-grade inflammation, known as inflammaging, contributes to tissue damage and disease. In the lungs, inflammaging leads to abnormal tissue remodeling, reduced function, and decreased immunity. A key factor in inflammaging is declining acetylcholine signaling, which normally suppresses inflammation and promotes tissue repair. We tested whether increasing acetylcholine responsiveness could reverse age-related lung damage. Aged mice were treated with donepezil to increase acetylcholine availability. After six months, blood oxygen saturation and voluntary activity were significantly improved. Histologically, treated mice showed a reversal of alveolar enlargement (a hallmark of emphysema) and complete restoration of elastic fibers. Donepezil treatment also dramatically increased bronchus-associated lymphoid tissue (iBALT) formation. iBALT is the repository of tissue-resident memory lymphocytes, including memory cholinergic lymphocytes that produce acetylcholine to suppress inflammation during secondary infections. The age-related loss of iBALT contributes to the increased risks associated with respiratory infection in the elderly. This indicates that age-related lung function and respiratory immune deficits can be modulated by improving acetylcholine signaling. Repurposing an approved medication provides a direct pathway to clinical application for improving respiratory health and infection resistance during aging.