RRC ID 19147
Author Athale J, Ulrich A, MacGarvey NC, Bartz RR, Welty-Wolf KE, Suliman HB, Piantadosi CA.
Title Nrf2 promotes alveolar mitochondrial biogenesis and resolution of lung injury in Staphylococcus aureus pneumonia in mice.
Journal Free Radic. Biol. Med.
Abstract Acute lung injury (ALI) initiates protective responses involving genes downstream of the Nrf2 (Nfe2l2) transcription factor, including heme oxygenase-1 (HO-1), which stimulates mitochondrial biogenesis and related anti-inflammatory processes. We examined mitochondrial biogenesis during Staphylococcus aureus pneumonia in mice and the effect of Nrf2 deficiency on lung mitochondrial biogenesis and resolution of lung inflammation. S. aureus pneumonia established by nasal insufflation of live bacteria was studied in mitochondrial reporter (mt-COX8-GFP) mice, wild-type (WT) mice, and Nrf2⁻/⁻ mice. Bronchoalveolar lavage, wet/dry ratios, real-time RT-PCR and Western analysis, immunohistochemistry, and fluorescence microscopy were performed on the lung at 0, 6, 24, and 48 h. The mice survived S. aureus inoculations at 5×10⁸ CFU despite diffuse lung inflammation and edema, but the Nrf2⁻/⁻ lung showed increased ALI. In mt-COX8-GFP mice, mitochondrial fluorescence was enhanced in bronchial and alveolar type II (AT2) epithelial cells. WT mice displayed rapid HO-1 upregulation and lower proinflammatory TNF-α, IL-1β, and CCL2 and, especially in AT2 cells, higher anti-inflammatory IL-10 and suppressor of cytokine signaling-3 than Nrf2⁻/⁻ mice. In the alveolar region, WT but not Nrf2⁻/⁻ mice showed strongly induced nuclear respiratory factor-1, PGC-1α, mitochondrial transcription factor-A, SOD2, Bnip3, mtDNA copy number, and citrate synthase. These findings indicate that S. aureus pneumonia induces Nrf2-dependent mitochondrial biogenesis in the alveolar region, mainly in AT2 cells. Absence of Nrf2 suppresses the alveolar transcriptional network for mitochondrial biogenesis and anti-inflammation, which worsens ALI. The findings link redox activation of mitochondrial biogenesis to ALI resolution.
Volume 53(8)
Pages 1584-94
Published 2012-10-15
DOI 10.1016/j.freeradbiomed.2012.08.009
PII S0891-5849(12)00498-4
PMID 22940620
PMC PMC3729022
MeSH Acute Lung Injury / etiology* Acute Lung Injury / metabolism Acute Lung Injury / pathology Animals Blotting, Western DNA, Mitochondrial / genetics DNA, Mitochondrial / metabolism Female Humans Immunoenzyme Techniques Inflammation Mediators / metabolism Interleukin-10 / genetics Interleukin-10 / metabolism Male Mice Mice, Inbred C57BL Mice, Transgenic Mitochondrial Turnover* NF-E2-Related Factor 2 / physiology* Oxidation-Reduction Pneumonia / etiology* Pneumonia / pathology Pneumonia, Staphylococcal / complications* Pneumonia, Staphylococcal / microbiology Pneumonia, Staphylococcal / pathology Pulmonary Alveoli / metabolism Pulmonary Alveoli / microbiology Pulmonary Alveoli / pathology* Pulmonary Edema / metabolism Pulmonary Edema / microbiology Pulmonary Edema / pathology RNA, Messenger / genetics Real-Time Polymerase Chain Reaction Reverse Transcriptase Polymerase Chain Reaction Staphylococcus aureus / pathogenicity Suppressor of Cytokine Signaling 3 Protein Suppressor of Cytokine Signaling Proteins / genetics Suppressor of Cytokine Signaling Proteins / metabolism Tumor Necrosis Factor-alpha / genetics Tumor Necrosis Factor-alpha / metabolism
IF 5.657
Times Cited 40
Mice Nrf2 knockout mouse/C57BL6J (RBRC01390)