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ROS-induced endothelial stress contributes to pulmonary fibrosis through pericytes and Wnt signaling.

Andersson Sjöland, Annika LU ; Karlsson, Jenny C LU and Rydell-Törmänen, Kristina LU (2015) In Laboratory Investigation
Abstract
Pulmonary fibrosis is a grave diagnosis with insidious progression, generally considered as a consequence of aberrant epithelial wound healing and excessive scarring. This process is commonly modeled in animals by local bleomycin administration, resulting in peribronchial inflammation and subsequent fibrosis. We have previously described initiation and early development of distal pulmonary fibrosis following repeated subcutaneous bleomycin injections (systemic administration). The aim of this study was to identify mechanisms for the development of pulmonary fibrosis, which we hypothesize is related to endothelial stress and activation. Bleomycin was administered subcutaneously 3 times/week during 0.33-4w, and parenchymal alterations were... (More)
Pulmonary fibrosis is a grave diagnosis with insidious progression, generally considered as a consequence of aberrant epithelial wound healing and excessive scarring. This process is commonly modeled in animals by local bleomycin administration, resulting in peribronchial inflammation and subsequent fibrosis. We have previously described initiation and early development of distal pulmonary fibrosis following repeated subcutaneous bleomycin injections (systemic administration). The aim of this study was to identify mechanisms for the development of pulmonary fibrosis, which we hypothesize is related to endothelial stress and activation. Bleomycin was administered subcutaneously 3 times/week during 0.33-4w, and parenchymal alterations were studied. In addition, we used microvascular endothelial cells to investigate effects of bleomycin in vitro. Our results confirmed that systemic administration of bleomycin exerts oxidative stress indicated by an increase in Sod1 at 0.33, 1, and 4w (P<0.05). Endothelial cells were activated (increased CD106 expression) from 1w and onwards (P<0.05), and p21 expression was increased 2-3 times throughout the study (P<0.05) as were the number of β-catenin-positive nuclei (P<0.001). Wnt3a was increased at 0.33, 1, and 4w (P<0.01) and Wnt5a from 1w and onwards (P<0.001). The present study suggests that bleomycin-induced reactive oxygen species (ROS) causes DNA stress affecting the endothelial niche, initiating repair processes including Wnt signaling. The repeated systemic administrations disrupt a normally fine-tuned balance in the Wnt signaling. In addition, pericyte differentiation was affected, which may have significant effects on fibrosis due to their ability to differentiate into myofibroblasts. We conclude that the endothelial niche may have an important role in the development of pulmonary fibrosis and warrants further investigations.Laboratory Investigation advance online publication, 14 September 2015; doi:10.1038/labinvest.2015.100. (Less)
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Laboratory Investigation
publisher
Nature Publishing Group
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  • pmid:26367492
  • scopus:84955600310
  • wos:000369269000009
ISSN
1530-0307
DOI
10.1038/labinvest.2015.100
language
English
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yes
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4cc641bd-e0d6-4cdc-91f1-95ee958ed6bd (old id 8042355)
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http://www.ncbi.nlm.nih.gov/pubmed/26367492?dopt=Abstract
date added to LUP
2015-10-04 13:25:58
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2017-09-17 08:16:16
@article{4cc641bd-e0d6-4cdc-91f1-95ee958ed6bd,
  abstract     = {Pulmonary fibrosis is a grave diagnosis with insidious progression, generally considered as a consequence of aberrant epithelial wound healing and excessive scarring. This process is commonly modeled in animals by local bleomycin administration, resulting in peribronchial inflammation and subsequent fibrosis. We have previously described initiation and early development of distal pulmonary fibrosis following repeated subcutaneous bleomycin injections (systemic administration). The aim of this study was to identify mechanisms for the development of pulmonary fibrosis, which we hypothesize is related to endothelial stress and activation. Bleomycin was administered subcutaneously 3 times/week during 0.33-4w, and parenchymal alterations were studied. In addition, we used microvascular endothelial cells to investigate effects of bleomycin in vitro. Our results confirmed that systemic administration of bleomycin exerts oxidative stress indicated by an increase in Sod1 at 0.33, 1, and 4w (P&lt;0.05). Endothelial cells were activated (increased CD106 expression) from 1w and onwards (P&lt;0.05), and p21 expression was increased 2-3 times throughout the study (P&lt;0.05) as were the number of β-catenin-positive nuclei (P&lt;0.001). Wnt3a was increased at 0.33, 1, and 4w (P&lt;0.01) and Wnt5a from 1w and onwards (P&lt;0.001). The present study suggests that bleomycin-induced reactive oxygen species (ROS) causes DNA stress affecting the endothelial niche, initiating repair processes including Wnt signaling. The repeated systemic administrations disrupt a normally fine-tuned balance in the Wnt signaling. In addition, pericyte differentiation was affected, which may have significant effects on fibrosis due to their ability to differentiate into myofibroblasts. We conclude that the endothelial niche may have an important role in the development of pulmonary fibrosis and warrants further investigations.Laboratory Investigation advance online publication, 14 September 2015; doi:10.1038/labinvest.2015.100.},
  author       = {Andersson Sjöland, Annika and Karlsson, Jenny C and Rydell-Törmänen, Kristina},
  issn         = {1530-0307},
  language     = {eng},
  month        = {09},
  publisher    = {Nature Publishing Group},
  series       = {Laboratory Investigation},
  title        = {ROS-induced endothelial stress contributes to pulmonary fibrosis through pericytes and Wnt signaling.},
  url          = {http://dx.doi.org/10.1038/labinvest.2015.100},
  year         = {2015},
}