Project description:To further understand the molecular pathogenesis of the 2009 pandemic H1N1 influenza virus infection, we profiled cellular miRNAs of lung tissue from BALB/c mice infected with influenza virus BJ501 and a mouse-adapted influenza virus A/Puerto Rico/8/34 (H1N1)(PR8) as a comparison.
Project description:Obesity is a risk factor for increased lung damage and disease severity during influenza virus infection. White adipose tissue (WAT) inflammation is a key driver of disease pathogenesis in obesity. While lung tissue immune cell pathogenic mechanisms are dogmatically studied in influenza virus infection, how obesity modifies lung and WAT immune cell character and contribution to amplify disease severity remains unknown. We show that obesity results in lung immune cells having a more inflammatory transcriptome in response to influenza infection than in the lean state. Further, in both lean and obese mice, influenza virus infection induces expression of inflammatory genes in visceral WAT and dominantly modifies the WAT immune cell milieu in obesity. Notably, obese influenza virus-infected mice exhibit a decrease in white adipose tissue macrophage (ATM) populations that inversely correlates with the increase in infiltrating lung macrophage numbers.
Project description:To further understand the molecular pathogenesis of the 2009 pandemic H1N1 influenza virus infection, we profiled cellular miRNAs of lung tissue from BALB/c mice infected with influenza virus BJ501 and a mouse-adapted influenza virus A/Puerto Rico/8/34 (H1N1)(PR8) as a comparison. Five groups of mice were selected, and three of each group were used to profile the miRNA, two were in case for unqualified RNA extraction. Whole lungs from mice infected by BJ501 or PR8 were harvested on 2,5 days post infection (dpi), and compared with lung samples from 5 uninfected mice.
Project description:The balance between protecting tissue integrity and efficient immune response is critical for host survival. Here we investigate the role of extracellular matrix (ECM) proteolysis in achieving this balance in the lung during influenza virus infection using a combined genomic and proteomic approach. We followed the transcriptional dynamics and ECM- related responses in a mouse model of influenza virus infection, integrated with whole tissue imaging and functional assays. Our study identifies MT1-MMP as a prominent host-ECM-remodeling collagenase in influenza virus infection. We show that selective inhibition of MT1-MMP-driven ECM proteolysis protects the tissue from infection-related structural and compositional damage. Inhibition of MT1-MMP did not significantly alter the immune response or cytokine expression, indicating its dominant role in ECM remodeling. We demonstrate that the available treatment for influenza virus (Tamiflu/ Oseltamivir) does not prevent lung ECM damage and is less effective than anti-MT1-MMP treatment in influenza virus and Streptococcus pneumoniae coinfection paradigms. Importantly, combination therapy of Tamiflu with anti-MT1-MMP shows a strong synergistic effect and results in complete recovery in mice. This study highlights the importance of tissue tolerance agents for surviving infectious diseases, and the potential of such host-pathogen therapy combination for respiratory infections.
Project description:The possibility of lung regeneration has been long discounted due to the irreversible nature of chronic lung diseases. However, patients who sustain massive loss of lung tissue during acute infections often recover full pulmonary function. Correspondingly, we previously demonstrated lung regeneration in mice following H1N1 influenza virus infection and implicated p63+Krt5+ distal airway stem cells, or DASCp63/Krt5, in this process. We show here that rare, preexisting DASCp63/K5 undergo a proliferative expansion in response to influenza and lineage-trace to nascent alveoli assembled at sites of interstitial inflammation. We also show that the ablation of DASCp63/Krt5 in vivo prevents the regeneration of lung tissue following influenza leading to pre-fibrotic lesions and deficient oxygen exchange. Finally, we demonstrate that exogenously cloned and propagated DASCp63/Krt5 readily contribute to lung regeneration following transplantation. The transplanted DASC ameliorated influenza-induced lung injury. These data suggest that DASCp63/K5 are required for lung regeneration and may have therapeutic utility in acute and chronic lung diseases. Stem cells before and after in vitro differentiation were subjected to whole genome microarray analysis. Duplicates were included for each sample. We used the Affymetrix Mouse Exon 1.0 ST platform
Project description:To identify molecular characteristics of lung tissue from WT mice treated with DMSO or a new insulin sensitizer MSDC-0602K at day 4 post influenza virus infection, we isolated RNA from lungs with various treatments and examined by bulk RNA-seq. We found a large number of gene profiles were altered following MSDC-0602K treatment in lungs. Interestingly, gene sets involved inflammatory responses were enriched in DMSO treatd mouse lungs whereas gene set of fatty acid metabolism was enriched in MSDC-0602K treated mouse lung, suggesting MSDC-0602K treatment diminshed pulmonary inflammation and altered metabolic status during influenza virus infection.
Project description:The possibility of lung regeneration has been long discounted due to the irreversible nature of chronic lung diseases. However, patients who sustain massive loss of lung tissue during acute infections often recover full pulmonary function. Correspondingly, we previously demonstrated lung regeneration in mice following H1N1 influenza virus infection and implicated p63+Krt5+ distal airway stem cells, or DASCp63/Krt5, in this process. We show here that rare, preexisting DASCp63/K5 undergo a proliferative expansion in response to influenza and lineage-trace to nascent alveoli assembled at sites of interstitial inflammation. We also show that the ablation of DASCp63/Krt5 in vivo prevents the regeneration of lung tissue following influenza leading to pre-fibrotic lesions and deficient oxygen exchange. Finally, we demonstrate that exogenously cloned and propagated DASCp63/Krt5 readily contribute to lung regeneration following transplantation. The transplanted DASC ameliorated influenza-induced lung injury. These data suggest that DASCp63/K5 are required for lung regeneration and may have therapeutic utility in acute and chronic lung diseases. DASC stem cells were ablated by Dtox treatment in Krt6:DTR mouse model. Control and stem cell ablated lungs were analyzed. We used the Affymetrix Mouse Exon 1.0 ST platform
Project description:The possibility of lung regeneration has been long discounted due to the irreversible nature of chronic lung diseases. However, patients who sustain massive loss of lung tissue during acute infections often recover full pulmonary function. Correspondingly, we previously demonstrated lung regeneration in mice following H1N1 influenza virus infection and implicated p63+Krt5+ distal airway stem cells, or DASCp63/Krt5, in this process. We show here that rare, preexisting DASCp63/K5 undergo a proliferative expansion in response to influenza and lineage-trace to nascent alveoli assembled at sites of interstitial inflammation. We also show that the ablation of DASCp63/Krt5 in vivo prevents the regeneration of lung tissue following influenza leading to pre-fibrotic lesions and deficient oxygen exchange. Finally, we demonstrate that exogenously cloned and propagated DASCp63/Krt5 readily contribute to lung regeneration following transplantation. These data suggest that DASCp63/K5 are required for lung regeneration and may have therapeutic utility in acute and chronic lung diseases. Tracheal epithelium and alveoli of healthy mice were laser capture microdissected for microarray analysis. Damaged lung interstitium (CD45+ region) of influenza infected (75pfu H1N1, 15dpi) mice were also dissected. Duplicates were included for each sample. We used the Affymetrix Mouse Exon 1.0 ST platform