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

Acosta-Herrera M, Lorenzo-Diaz F, Pino-Yanes M, Corrales A, Valladares F, Klassert TE, Valladares B, Slevogt H, Ma SF, Villar J, Flores C - PLoS ONE (2015)

Bottom Line: However, it is currently unknown how they exert the protective effects.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.

View Article: PubMed Central - PubMed

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.

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.

No MeSH data available.


Related in: MedlinePlus

Venn diagram illustrating the distribution of statistically significant changes in gene expression and their overlap among experimental groups.SS: Sepsis spontaneous breathing, SLVT: septic with low tidal volume MV, SHVT: septic with high tidal volume MV. All the comparisons were made against the non-septic controls (NA).
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pone.0132296.g004: Venn diagram illustrating the distribution of statistically significant changes in gene expression and their overlap among experimental groups.SS: Sepsis spontaneous breathing, SLVT: septic with low tidal volume MV, SHVT: septic with high tidal volume MV. All the comparisons were made against the non-septic controls (NA).

Mentions: After quality control procedures, gene expression analyses were finally performed with a total of ten animals (S1 Fig). Based on power calculations, such reductions in the final sample size still ensured sufficient statistical power (>76%) for downstream transcriptomic analyses (Fig 2). A complete flow diagram showing the main steps of these analyses and the main results of our study are depicted in Fig 3. Differential gene expression revealed 2,859 deregulated probe sets with FDR≤0.05 and FC≥1.7 in the overall experiment with respect to the control (NA): 1,044 in SS group, 1,464 in SLVT group and 1,714 in the SHVT group (S1 Table and Fig 4). A comparison with SAM [17], an alternative and widely used algorithm for differential expression experiments, provided >85% overlap in the deregulated probe sets (S2 Fig). Furthermore, the validity of the microarray results was supported by the high correlation observed for eight deregulated genes between ∆Ct values obtained by qPCR and their normalized microarray intensities (Spearman rank, R = 0.875) (Fig 5).


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

Acosta-Herrera M, Lorenzo-Diaz F, Pino-Yanes M, Corrales A, Valladares F, Klassert TE, Valladares B, Slevogt H, Ma SF, Villar J, Flores C - PLoS ONE (2015)

Venn diagram illustrating the distribution of statistically significant changes in gene expression and their overlap among experimental groups.SS: Sepsis spontaneous breathing, SLVT: septic with low tidal volume MV, SHVT: septic with high tidal volume MV. All the comparisons were made against the non-septic controls (NA).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4492998&req=5

pone.0132296.g004: Venn diagram illustrating the distribution of statistically significant changes in gene expression and their overlap among experimental groups.SS: Sepsis spontaneous breathing, SLVT: septic with low tidal volume MV, SHVT: septic with high tidal volume MV. All the comparisons were made against the non-septic controls (NA).
Mentions: After quality control procedures, gene expression analyses were finally performed with a total of ten animals (S1 Fig). Based on power calculations, such reductions in the final sample size still ensured sufficient statistical power (>76%) for downstream transcriptomic analyses (Fig 2). A complete flow diagram showing the main steps of these analyses and the main results of our study are depicted in Fig 3. Differential gene expression revealed 2,859 deregulated probe sets with FDR≤0.05 and FC≥1.7 in the overall experiment with respect to the control (NA): 1,044 in SS group, 1,464 in SLVT group and 1,714 in the SHVT group (S1 Table and Fig 4). A comparison with SAM [17], an alternative and widely used algorithm for differential expression experiments, provided >85% overlap in the deregulated probe sets (S2 Fig). Furthermore, the validity of the microarray results was supported by the high correlation observed for eight deregulated genes between ∆Ct values obtained by qPCR and their normalized microarray intensities (Spearman rank, R = 0.875) (Fig 5).

Bottom Line: However, it is currently unknown how they exert the protective effects.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.

View Article: PubMed Central - PubMed

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.

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.

No MeSH data available.


Related in: MedlinePlus