Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Letter
  • Published:

A GABAergic system in airway epithelium is essential for mucus overproduction in asthma

Abstract

γ-Aminobutyric acid (GABA) is an important neurotransmitter that, through the subtype A GABA receptor (GABAAR), induces inhibition in the adult brain. Here we show that an excitatory, rather than inhibitory, GABAergic system exists in airway epithelial cells. Both GABAARs and the GABA synthetic enzyme glutamic acid decarboxylase (GAD) are expressed in pulmonary epithelial cells. Activation of GABAARs depolarized these cells. The expression of GAD in the cytosol and GABAARs in the apical membranes of airway epithelial cells increased markedly when mice were sensitized and then challenged with ovalbumin, an approach for inducing allergic asthmatic reactions. Similarly, GAD and GABAARs in airway epithelial cells of humans with asthma increased after allergen inhalation challenge. Intranasal application of selective GABAAR inhibitors suppressed the hyperplasia of goblet cells and the overproduction of mucus induced by ovalbumin or interleukin-13 in mice. These findings show that a previously unknown epithelial GABAergic system has an essential role in asthma.

This is a preview of subscription content, access via your institution

Access options

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Figure 1: An excitatory GABAergic system in lung epithelial cells.
Figure 2: OVA treatments increase the expression of airway GABAergic signaling components.
Figure 3: Pulmonary IL-13 increases during allergic asthma and stimulates the expression of GAD65/67 and GABAARs in airway epithelial cells.
Figure 4: GABAergic blockade decreases OVA-induced airway goblet cell hyperplasia and mucus overproduction.

Similar content being viewed by others

References

  1. Holgate, S.T. et al. Epithelial-mesenchymal communication in the pathogenesis of chronic asthma. Proc. Am. Thorac. Soc. 1, 93–98 (2004).

    Article  CAS  Google Scholar 

  2. Jin, N., Narasaraju, T., Kolliputi, N., Chen, J. & Liu, L. Differential expression of GABAA receptor pi subunit in cultured rat alveolar epithelial cells. Cell Tissue Res. 321, 173–183 (2005).

    Article  CAS  Google Scholar 

  3. Kittler, J.T. & Moss, S.J. Modulation of GABAA receptor activity by phosphorylation and receptor trafficking: implications for the efficacy of synaptic inhibition. Curr. Opin. Neurobiol. 13, 341–347 (2003).

    Article  CAS  Google Scholar 

  4. Treiman, D.M. GABAergic mechanisms in epilepsy. Epilepsia 42 (Suppl. 3), 8–12 (2001).

    Article  Google Scholar 

  5. Whiting, P.J. The GABAA receptor gene family: new opportunities for drug development. Curr. Opin. Drug Discov. Devel. 6, 648–657 (2003).

    CAS  PubMed  Google Scholar 

  6. Hocking, D.C. & Chang, C.H. Fibronectin matrix polymerization regulates small airway epithelial cell migration. Am. J. Physiol. Lung Cell. Mol. Physiol. 285, L169–L179 (2003).

    Article  CAS  Google Scholar 

  7. Ware, L.B., Fang, X. & Matthay, M.A. Protein C and thrombomodulin in human acute lung injury. Am. J. Physiol. Lung Cell. Mol. Physiol. 285, L514–L521 (2003).

    Article  CAS  Google Scholar 

  8. Takeyama, K. et al. Epidermal growth factor system regulates mucin production in airways. Proc. Natl. Acad. Sci. USA 96, 3081–3086 (1999).

    Article  CAS  Google Scholar 

  9. Rogers, D.F. Airway goblet cell hyperplasia in asthma: hypersecretory and anti-inflammatory? Clin. Exp. Allergy 32, 1124–1127 (2002).

    Article  Google Scholar 

  10. Singer, M. et al. A MARCKS-related peptide blocks mucus hypersecretion in a mouse model of asthma. Nat. Med. 10, 193–196 (2004).

    Article  CAS  Google Scholar 

  11. Grunig, G. et al. Requirement for IL-13 independently of IL-4 in experimental asthma. Science 282, 2261–2263 (1998).

    Article  CAS  Google Scholar 

  12. Kuperman, D.A. et al. Direct effects of interleukin-13 on epithelial cells cause airway hyperreactivity and mucus overproduction in asthma. Nat. Med. 8, 885–889 (2002).

    Article  CAS  Google Scholar 

  13. Han, X. et al. Chlamydia infection induces ICOS ligand-expressing and IL-10-producing dendritic cells that can inhibit airway inflammation and mucus overproduction elicited by allergen challenge in BALB/c mice. J. Immunol. 176, 5232–5239 (2006).

    Article  CAS  Google Scholar 

  14. Serantes, R. et al. Interleukin-1β enhances GABAA receptor cell-surface expression by a phosphatidylinositol 3-kinase/Akt pathway: relevance to sepsis-associated encephalopathy. J. Biol. Chem. 281, 14632–14643 (2006).

    Article  CAS  Google Scholar 

  15. Represa, A. & Ben-Ari, Y. Trophic actions of GABA on neuronal development. Trends Neurosci. 28, 278–283 (2005).

    Article  CAS  Google Scholar 

  16. Dunnill, M.S. The pathology of asthma, with special reference to changes in the bronchial mucosa. J. Clin. Pathol. 13, 27–33 (1960).

    Article  CAS  Google Scholar 

  17. Fahy, J.V. Goblet cell and mucin gene abnormalities in asthma. Chest 122, 320S–326S (2002).

    Article  CAS  Google Scholar 

  18. Hirota, J.A., Ellis, R. & Inman, M.D. Regional differences in the pattern of airway remodeling following chronic allergen exposure in mice. Respir. Res. 7, 120 (2006).

    Article  Google Scholar 

  19. Wang, S. et al. IL-12-dependent vascular cell adhesion molecule-1 expression contributes to airway eosinophilic inflammation in a mouse model of asthma-like reaction. J. Immunol. 166, 2741–2749 (2001).

    Article  CAS  Google Scholar 

  20. Dong, H. et al. Excessive expression of acetylcholinesterase impairs glutamatergic synaptogenesis in hippocampal neurons. J. Neurosci. 24, 8950–8960 (2004).

    Article  CAS  Google Scholar 

  21. Cockcroft, D.W., Killian, D.N., Mellon, J.J. & Hargreave, F.E. Protective effect of drugs on histamine-induced asthma. Thorax 32, 429–437 (1977).

    Article  CAS  Google Scholar 

  22. O'Byrne, P.M., Dolovich, J. & Hargreave, F.E. Late asthmatic responses. Am. Rev. Respir. Dis. 136, 740–751 (1987).

    Article  CAS  Google Scholar 

  23. Inman, M.D. et al. Reproducibility of allergen-induced early and late asthmatic responses. J. Allergy Clin. Immunol. 95, 1191–1195 (1995).

    Article  CAS  Google Scholar 

  24. Gauvreau, G.M. et al. Repeatability of allergen-induced airway inflammation. J. Allergy Clin. Immunol. 104, 66–71 (1999).

    Article  CAS  Google Scholar 

  25. Workshop summary and guidelines: investigative use of bronchoscopy, lavage, and bronchial biopsies in asthma and other airway diseases. J. Allergy Clin. Immunol. 88 808–814 (1991).

  26. Xiang, Y.Y. et al. Versican G3 domain regulates neurite growth and synaptic transmission of hippocampal neurons by activation of epidermal growth factor receptor. J. Biol. Chem. 281, 19358–19368 (2006).

    Article  CAS  Google Scholar 

  27. Fang, X. et al. Contribution of CFTR to apical-basolateral fluid transport in cultured human alveolar epithelial type II cells. Am. J. Physiol. Lung Cell. Mol. Physiol. 290, L242–L249 (2006).

    Article  CAS  Google Scholar 

  28. Yang, X., Gieni, R.S., Mosmann, T.R. & HayGlass, K.T. Chemically modified antigen preferentially elicits induction of Th1-like cytokine synthesis patterns in vivo. J. Exp. Med. 178, 349–353 (1993).

    Article  CAS  Google Scholar 

  29. Baufreton, J., Atherton, J.F., Surmeier, D.J. & Bevan, M.D. Enhancement of excitatory synaptic integration by GABAergic inhibition in the subthalamic nucleus. J. Neurosci. 25, 8505–8517 (2005).

    Article  CAS  Google Scholar 

Download references

Acknowledgements

We thank M. Matthay (University of California) for isolated primary human type II epithelial cells; J. MacDonald, Y.T. Wang, M. Post, D. Bieger and M. Jackson for comments on the manuscript; B. Han for comments on some experiments; M. Zhuo and L. Wu for assistance in analysis of confocal microscopy; and J. Wattie and R. Ellis for assistance in the AHR experiment. This study was supported by grant MOP74653 (to W.-Y.L.) and grant MT-14680 (to X.Y.) from the Canadian Institutes of Health Research (CIHR). X.Y. is Canada Research Chair in Infection and Immunity. W.-Y.L is CIHR New Investigator.

Author information

Authors and Affiliations

Authors

Corresponding authors

Correspondence to Xi Yang or Wei-Yang Lu.

Ethics declarations

Competing interests

The authors are filing a patent application for the role of the epithelial GABAA receptor signaling system in mucus production.

Supplementary information

Supplementary Fig. 1

RT-PCR assays of GAD and GABAAR subunits in BEAS-2B cells. (PDF 82 kb)

Supplementary Fig. 2

The selective GABAAR antagonist bicuculline blocks the GABA-induced current in pulmonary EC cells. (PDF 24 kb)

Supplementary Fig. 3

The intracellular and extracellular alcian blue staining increase in the SAEC after GABA treatment. (PDF 45 kb)

Supplementary Fig. 4

The expression of GAD and GABAAR subunits increases in the lung of OVA-treated mice. (PDF 76 kb)

Supplementary Fig. 5

GABAAR β2 and β3 subunits are not expressed in the airway smooth muscle cells. (PDF 115 kb)

Supplementary Fig. 6

The expression levels of GAD and GABAARs do not increase in the airway epithelial cells in OVA-challenged IL-13 knockout mice. (PDF 115 kb)

Supplementary Fig. 7

GABAAR inhibitor does not affect inflammatory cells infiltration to the lung. (PDF 30 kb)

Supplementary Methods (PDF 37 kb)

Rights and permissions

Reprints and permissions

About this article

Cite this article

Xiang, YY., Wang, S., Liu, M. et al. A GABAergic system in airway epithelium is essential for mucus overproduction in asthma. Nat Med 13, 862–867 (2007). https://doi.org/10.1038/nm1604

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nm1604

This article is cited by

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing