The Nrf2-SLPI axis in aging and its role in the pathophysiology of pulmonarycomplex disease.

Abstract

Aging is associated with a poor prognosis in pulmonarycomplex (MAC) disease. This study aimed to elucidate the impact of aging on pulmonary MAC disease and its underlying mechanisms. Young and old mice were intranasally infected with. RNA-seq analysis was performed on lung tissues to identify age-related gene expression changes. Whole blood cells from 100 untreated patients with pulmonary MAC disease were analyzed formRNA expression and its association with age and disease severity. Old mice were more susceptible to MAC infection than young mice, with increased bacterial load and decreased expression of secretory leukocyte protease inhibitor (SLPI) in the lungs. SLPI showed direct antimicrobial activity againstand was regulated by Nrf2, a transcription factor with reduced activity in infected old mice. Nrf2-deficient mice showed decreasedexpression and increased bacterial load. Treatment with sulforaphane restoredexpression and reduced bacterial burden in old mice. In humans, cluster analysis identified three clusters based on age andexpression. Compared to cluster 1 (C1) (younger age and high SLPI), cluster C3 (older age and lower SLPI) had larger pulmonary lesions on computed tomography. Pathway analysis indicated reduced Nrf2 activation in C3 than in C1, consistent with the findings in the mouse experiments. The study suggests that age-related reductions in Nrf2 activity andexpression contribute to poor outcomes in pulmonary MAC disease. Targeting the Nrf2-SLPI axis may represent a novel therapeutic approach for elderly patients.