Lung Transcriptomics during Protective Ventilatory Support in Sepsis-Induced Acute Lung Injury

PLoS One. 2015 Jul 6;10(7):e0132296. doi: 10.1371/journal.pone.0132296. eCollection 2015.

Abstract

Acute lung injury (ALI) is a severe inflammatory process of the lung. The only proven life-saving support is mechanical ventilation (MV) using low tidal volumes (LVT) plus moderate to high levels of positive end-expiratory pressure (PEEP). However, it is currently unknown how they exert the protective effects. To identify the molecular mechanisms modulated by protective MV, this study reports transcriptomic analyses based on microarray and microRNA sequencing in lung tissues from a clinically relevant animal model of sepsis-induced ALI. Sepsis was induced by cecal ligation and puncture (CLP) in male Sprague-Dawley rats. At 24 hours post-CLP, septic animals were randomized to three ventilatory strategies: spontaneous breathing, LVT (6 ml/kg) plus 10 cmH2O PEEP and high tidal volume (HVT, 20 ml/kg) plus 2 cmH2O PEEP. Healthy, non-septic, non-ventilated animals served as controls. After 4 hours of ventilation, lung samples were obtained for histological examination and gene expression analysis using microarray and microRNA sequencing. Validations were assessed using parallel analyses on existing publicly available genome-wide association study findings and transcriptomic human data. The catalogue of deregulated processes differed among experimental groups. The 'response to microorganisms' was the most prominent biological process in septic, non-ventilated and in HVT animals. Unexpectedly, the 'neuron projection morphogenesis' process was one of the most significantly deregulated in LVT. Further support for the key role of the latter process was obtained by microRNA studies, as four species targeting many of its genes (Mir-27a, Mir-103, Mir-17-5p and Mir-130a) were found deregulated. Additional analyses revealed 'VEGF signaling' as a central underlying response mechanism to all the septic groups (spontaneously breathing or mechanically ventilated). Based on this data, we conclude that a co-deregulation of 'VEGF signaling' along with 'neuron projection morphogenesis', which have been never anticipated in ALI pathogenesis, promotes lung-protective effects of LVT with high levels of PEEP.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acute Lung Injury / etiology
  • Acute Lung Injury / metabolism*
  • Acute Lung Injury / pathology
  • Acute Lung Injury / therapy
  • Animals
  • Gene Expression Profiling*
  • Humans
  • Lung / metabolism*
  • Lung / pathology
  • Male
  • MicroRNAs / biosynthesis*
  • Rats
  • Rats, Sprague-Dawley
  • Respiration, Artificial*
  • Sepsis / complications
  • Sepsis / metabolism*
  • Sepsis / pathology
  • Sepsis / therapy
  • Signal Transduction*
  • Vascular Endothelial Growth Factor A / biosynthesis*

Substances

  • MicroRNAs
  • Vascular Endothelial Growth Factor A
  • vascular endothelial growth factor A, rat

Grants and funding

This work was supported by CB06/06/1088, PI10/0393 and PI14/00844 from Instituto de Salud Carlos III, Spain, and co-financed by the European Regional Development Funds, "A way of making Europe" from the European Union to JV and CF. MAH and FLD were supported with fellowships from Instituto de Salud Carlos III (FI11/00074 and Sara Borrell CD13/00304, respectively). MPY was funded by Fundación Ramón Areces. TEK and HS were supported by the German Research Foundation (Collaborative Research Center/Transregio 124, A5) and the German Federal Ministry of Education and Research (BMBF 03Z2JN22). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.