Impaired defenses of neonatal mouse alveolar macrophage withcftrdeletion are modulated by glutathione and TGFβ1.
Our understanding of the intrinsic effects of cystic fibrosis (CF) transmembrane conductance regulator (cftr) deletion on resident neonatal alveolar macrophage (AM) remains limited. We previously demonstrated that diminished glutathione (GSH) or excessive AM transforming growth factor beta one (TGFβ1) contributes to AM dysfunction in a variety of disease states. In this study, using a gut-correctedcftrneonatal knockout (KO) mouse model and a siRNA-manipulated macrophage-like cell line (THP-1 cell), we hypothesized (1) thatcftrmutation alone increases neonatal AM oxidant stress and cellular TGFβ1 signaling via altered GSH, thereby impairing cellular function, and (2) that exogenous GSH attenuates AM alterations and dysfunction in the KO AM In neonatal KO mice, the baseline bronchoalveolar lavage fluid demonstrated a near doubling in mixed disulfides (P≤ 0.05) and oxidized GSSG (P≤ 0.05) without concurrent inflammation compared to WT littermates. KO AM demonstrated diminished AM thiols (P≤ 0.05), increased AM mitochondrial ROS (P≤ 0.05), increased AM TGFβ1 (P≤ 0.05) with increased TGFβ1 signaling (P≤ 0.05), and impaired phagocytosis (P≤ 0.05). KO AM mitochondrial ROS was modulated by exogenous GSH (P≤ 0.05). Conversely, TGFβ1 was reduced (P≤ 0.05) and impaired phagocytosis was rescued (P≤ 0.05) by exogenous GSH in the KO AM These results suggest that an altered neonatal AM phenotype may contribute to the initiation of lung inflammation/infection in the CF lung. Modulation of the AM in the neonatal CF lung may potentially alter progression of disease.
Department of Pediatrics, Division of Neonatal-Perinatal Medicine, Emory University School of Medicine, Atlanta, Georgia tgauthi@emory.edu.
Theresa W
TW
Gauthier
Division of Pediatric Critical Care Medicine, Children's Healthcare of Atlanta, Emory University School of Medicine, Atlanta, Georgia.
Jocelyn R
JR
Grunwell
Department of Pediatrics, Division of Neonatal-Perinatal Medicine, Emory University School of Medicine, Atlanta, Georgia.
Xiao-Du
XD
Ping
Department of Pediatrics, Division of Neonatal-Perinatal Medicine, Emory University School of Medicine, Atlanta, Georgia.
Frank L
FL
Harris
Department of Pediatrics, Division of Neonatal-Perinatal Medicine, Emory University School of Medicine, Atlanta, Georgia.
Lou Ann S
LA
Brown
D000818:Animals; D001992:Bronchoalveolar Lavage Fluid; D002460:Cell Line; D019005:Cystic Fibrosis Transmembrane Conductance Regulator / Q000235:genetics* / Q000378:metabolism; D005978:Glutathione / Q000494:pharmacology*; D016676:Macrophages, Alveolar / Q000187:drug effects / Q000378:metabolism*; D051379:Mice; D018181:Mice, Inbred CFTR; D018345:Mice, Knockout; D018384:Oxidative Stress / Q000187:drug effects / Q000502:physiology*; D010587:Phagocytosis / Q000187:drug effects / Q000502:physiology; D053773:Transforming Growth Factor beta1 / Q000378:metabolism*
D053773:Transforming Growth Factor beta1; D019005:Cystic Fibrosis Transmembrane Conductance Regulator; D005978:Glutathione
Alveolar macrophage; cystic fibrosis; mouse; newborn; transforming growth factor beta one