Volume 4 Supplement 1

3rd Pediatric Allergy and Asthma Meeting (PAAM)

Open Access

PD07 - TNF-α and hypoxia alter the expression of ASM cell contractile protein genes

  • Nikolaos Tsiougkos1,
  • Stamatina Tsapournioti1,
  • Paschalis-Adam Molyvdas1 and
  • Efrosyni Paraskeva1
Clinical and Translational Allergy20144(Suppl 1):P7

https://doi.org/10.1186/2045-7022-4-S1-P7

Published: 28 February 2014

Background

Recent research on airway smooth muscle (ASM) cell biology and function has significantly broadened our understanding of the role these cells play in asthma. Apart from being structural contractile cells, they also have immunomodulatory properties. Dynamic multifunctional behavior of ASM cells, namely phenotype plasticity and functional diversity, is now-recognized to be directly involved with tissue inflammation that often interrelates with hypoxia in orchestrating airway remodeling and hyperresponsiveness characteristic of asthma.

Objective

Herein, we sought to investigate the effect of the inflammatory mediator TNF-α and/or hypoxia on the expression of the ASM cell contractile markers SMMHC (smooth muscle myosin heavy chain), MLCK (myosin light chain kinase), α2 αctin and SM22.

Method

Primary in vitro differentiated human bronchial ASM cell cultures were incubated for 24 hours in the presence or absence of TNF-α under normoxia or hypoxia. Total RNA was extracted, reverse transcribed and mRNA expression levels of SMMHC, MLCK, a2 αctin and SM22 were determined by quantitative real-time PCR.

Results

TNF-α remarkably increased SMMHC mRNA expression under both normoxia and hypoxia. Treatment under hypoxia, with TNF-α, or their combination decreased MLCK and SM22 mRNA levels. In contrast, α2 αctin mRNA levels were not significantly affected under any of these conditions.

Conclusion

TNF-α and hypoxia appear to alter the expression of human bronchial ASM cell contractile protein genes, providing new insights on the complex role of ASM cells in the pathophysiology of asthma. Remarkable up-regulation of SMMHC mRNA by TNF-α is indicative of the excessive ASM hypertrophy in severe asthma.

Authors’ Affiliations

(1)
Laboratory of Physiology, Faculty of Medicine, University of Thessaly

Copyright

© Tsiougkos et al; licensee BioMed Central Ltd. 2014

This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.

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