title: Lung Transcriptomics during Protective Ventilatory Support in Sepsis-Induced Acute Lung Injury.
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.
authors.affiliation: CIBER de Enfermedades Respiratorias, Instituto de Salud Carlos III, Madrid, Spain; Research Unit, Hospital Universitario N.S. de Candelaria, Santa Cruz de Tenerife, Spain; Research Unit, Hospital Universitario Dr. Negrin, Las Palmas de Gran Canaria, Spain.
authors.forename: Marialbert
authors.initials: M
authors.lastname: Acosta-Herrera
authors.affiliation: CIBER de Enfermedades Respiratorias, Instituto de Salud Carlos III, Madrid, Spain; Research Unit, Hospital Universitario N.S. de Candelaria, Santa Cruz de Tenerife, Spain; Instituto Universitario de Enfermedades Tropicales y Salud Pública de Canarias, Universidad de La Laguna, Santa Cruz de Tenerife, Spain.
authors.forename: Fabian
authors.initials: F
authors.lastname: Lorenzo-Diaz
authors.affiliation: CIBER de Enfermedades Respiratorias, Instituto de Salud Carlos III, Madrid, Spain; Research Unit, Hospital Universitario N.S. de Candelaria, Santa Cruz de Tenerife, Spain; Department of Medicine, University of California San Francisco, San Francisco, California, United States of America.
authors.forename: Maria
authors.initials: M
authors.lastname: Pino-Yanes
authors.affiliation: CIBER de Enfermedades Respiratorias, Instituto de Salud Carlos III, Madrid, Spain; Research Unit, Hospital Universitario N.S. de Candelaria, Santa Cruz de Tenerife, Spain.
authors.forename: Almudena
authors.initials: A
authors.lastname: Corrales
authors.affiliation: CIBER de Enfermedades Respiratorias, Instituto de Salud Carlos III, Madrid, Spain; Department of Anatomy, Pathology and Histology, University of La Laguna, Santa Cruz de Tenerife, Spain.
authors.forename: Francisco
authors.initials: F
authors.lastname: Valladares
authors.affiliation: Septomics Research Centre, Jena University Hospital, Jena, Germany.
authors.forename: Tilman E
authors.initials: TE
authors.lastname: Klassert
authors.affiliation: Instituto Universitario de Enfermedades Tropicales y Salud Pública de Canarias, Universidad de La Laguna, Santa Cruz de Tenerife, Spain.
authors.forename: Basilio
authors.initials: B
authors.lastname: Valladares
authors.affiliation: Septomics Research Centre, Jena University Hospital, Jena, Germany.
authors.forename: Hortense
authors.initials: H
authors.lastname: Slevogt
authors.affiliation: Section of Pulmonary and Critical Care Medicine, University of Chicago, Chicago, Illinois, United States of America.
authors.forename: Shwu-Fan
authors.initials: SF
authors.lastname: Ma
authors.affiliation: CIBER de Enfermedades Respiratorias, Instituto de Salud Carlos III, Madrid, Spain; Research Unit, Hospital Universitario Dr. Negrin, Las Palmas de Gran Canaria, Spain; Keenan Research Center for Biomedical Science at the Li KaShing Knowledge Institute, St. Michael´s Hospital, Toronto, Canada.
authors.forename: Jesus
authors.initials: J
authors.lastname: Villar
authors.affiliation: CIBER de Enfermedades Respiratorias, Instituto de Salud Carlos III, Madrid, Spain; Research Unit, Hospital Universitario N.S. de Candelaria, Santa Cruz de Tenerife, Spain; Instituto Universitario de Enfermedades Tropicales y Salud Pública de Canarias, Universidad de La Laguna, Santa Cruz de Tenerife, Spain.
authors.forename: Carlos
authors.initials: C
authors.lastname: Flores
mesh_terms: D055371:Acute Lung Injury / Q000209:etiology / Q000378:metabolism* / Q000473:pathology / Q000628:therapy; D000818:Animals; D020869:Gene Expression Profiling; D006801:Humans; D008168:Lung / Q000378:metabolism* / Q000473:pathology; D008297:Male; D035683:MicroRNAs / Q000096:biosynthesis*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012121:Respiration, Artificial; D018805:Sepsis / Q000150:complications / Q000378:metabolism* / Q000473:pathology / Q000628:therapy; D015398:Signal Transduction; D042461:Vascular Endothelial Growth Factor A / Q000096:biosynthesis*
chemical_list: D035683:MicroRNAs; D042461:Vascular Endothelial Growth Factor A; C467498:vascular endothelial growth factor A, rat