β2-Adrenoceptor agonists are required for development of the asthma phenotype in a murine model.

Published

Journal Article

β(2)-Adrenoceptor (β2AR) agonists are the most effective class of bronchodilators and a mainstay of asthma management. The first potent β2AR agonist discovered and widely used in reversing the airway constriction associated with asthma exacerbation was the endogenous activator of the β2AR, epinephrine. In this study, we demonstrate that activation of the β2AR by epinephrine is paradoxically required for development of the asthma phenotype. In an antigen-driven model, mice sensitized and challenged with ovalbumin showed marked elevations in three cardinal features of the asthma phenotype: inflammatory cells in their bronchoalveolar lavage fluid, mucin over production, and airway hyperresponsiveness. However, genetic depletion of epinephrine using mice lacking the enzyme to synthesize epinephrine, phenylethanolamine N-methyltransferase, or mice that had undergone pharmacological sympathectomy with reserpine to deplete epinephrine, had complete attenuation of these three cardinal features of the asthma phenotype. Furthermore, administration of the long-acting β2AR agonist, formoterol, a drug currently used in asthma treatment, to phenylethanolamine N-methyltransferase-null mice restored the asthma phenotype. We conclude that β2AR agonist-induced activation is needed for pathogenesis of the asthma phenotype. These findings also rule out constitutive signaling by the β2AR as sufficient to drive the asthma phenotype, and may help explain why chronic administration of β2AR agonists, such as formoterol, have been associated with adverse outcomes in asthma. These data further support the hypothesis that chronic asthma management may be better served by treatment with certain "β-blockers."

Full Text

Duke Authors

Cited Authors

  • Thanawala, VJ; Forkuo, GS; Al-Sawalha, N; Azzegagh, Z; Nguyen, LP; Eriksen, JL; Tuvim, MJ; Lowder, TW; Dickey, BF; Knoll, BJ; Walker, JKL; Bond, RA

Published Date

  • February 2013

Published In

Volume / Issue

  • 48 / 2

Start / End Page

  • 220 - 229

PubMed ID

  • 23204390

Pubmed Central ID

  • 23204390

Electronic International Standard Serial Number (EISSN)

  • 1535-4989

International Standard Serial Number (ISSN)

  • 1044-1549

Digital Object Identifier (DOI)

  • 10.1165/rcmb.2012-0364OC

Language

  • eng