Parenchymal and Inflammatory Cell Responses to Single and Repeated Ozone Exposure in Healthy and Surfactant Protein-C Mutant Lung. (22nd July 2022)

• Record Type: Journal Article
• Authors: Nguyen, Jacklyn; Deering-Rice, Cassandra E; Armstrong, Brittnie S; Massa, Christopher; Reilly, Christopher A; Venosa, Alessandro
• Is Part Of: Toxicological sciences. Volume 189:Number 1(2022)
• Page Start: 107
• Page End: 123
• Publication Date: 2022-07-22
• Subjects: ozone -- environmental exposure -- inflammation -- pulmonary toxicity; Toxicology -- Periodicals; Toxicology -- Periodicals; Toxicology; Periodicals; 615.9
• DOI: 10.1093/toxsci/kfac074
• Languages: English
• ISSNs: 1096-6080

Abstract

Abstract: Mutations in the alveolar epithelial-specific gene encoding for surfactant protein C (SP-C) are linked to pulmonary disease. Ozone (O3 ) is a ubiquitous pollutant known to exacerbate stress through oxidative injury and inflammation. To comprehend the structural, functional, and immunological impact of single and repeated O3 exposure, SP-C WT and surfactant protein-C I73T mutant (SP-C I73T ) mice were exposed to air or O3 (0.8 ppm, 3 h, up to ×4 consecutive days). O3 was associated with mitochondrial and autophagic activation (PINK1, LC3B, and p62), focal remodeling, and inflammation localized at the terminal bronchiole-to-alveolar junctions. Histological damage was exacerbated by repeated exposure. Single O3 challenge resulted in transient elastin fiber loss, whereas repeated exposure resulted in marked increases in elastance in SP-C I73T mice. Flow cytometric analysis revealed increases in classical monocyte and monocyte-derived macrophages recruitment in conditions of repeated exposure, which peaked earlier (24 h) in SP-C I73T mice. Immunohistochemical analysis also showed clustering of Arg-1 + and CD206 + activated cells within regions of remodeled lung. Lymphoid cell analysis identified CX3 CR1 - B220 + B cells accumulating after single (24/72 h). Repeated exposure produces a switch in the phenotype of these B cells CX3 CR1 + (72 h) only in SP-C WT mice. SP-C I73T mutants also displayed depletion in NK1.1 + NKp46 + natural killer cells in lung, as well as bone marrow, blood, and spleen. These results illustrate the cumulative impact of O3 on lung structure and function in healthy lung, and aberrant myeloid and lymphoid recruitment in SP-C mutants responding to challenge. Together, this work highlights the significance of modeling environmental exposure across the spectrum of genetic susceptibility, consistent with human disease.