Chloride ion transport and overexpression of TMEM16A in a guinea-pig asthma model

Clin Exp Allergy. 2017 Jun;47(6):795-804. doi: 10.1111/cea.12887. Epub 2017 Feb 20.


Background: TMEM16A, a Ca-activated Cl channel, regulates various physiological functions such as mucin secretion. However, the role of TMEM16A in hyper-secretion in asthma is not fully understood.

Objective: The aim of this study is to evaluate Cl ion transport via TMEM16A and determine the localization of TMEM16A in a guinea-pig asthma model.

Methods: Guinea-pigs were sensitized with ovalbumin (OVA) i.p. on Days 1 and 8. On Day 22, we assessed OVA challenge-induced Cl ion transport in the sensitized tracheas ex vivo in an Ussing chamber, compared with the non-sensitized tracheas. We then examined the effect of T16Ainh-A01, a TMEM16A inhibitor, on the increase in Cl ion transport. The tracheal epithelium was immunostained with an anti-TMEM16A antibody. Epithelial cells from guinea-pig tracheas were cultured at the air-liquid interface in the presence of IL-13 for in vitro study. We studied the effect of TMEM16A inhibitors on Ca-dependent agonist, uridine triphosphate (UTP)-induced increases in Cl ion transport in the cultured cells. The cells were immunostained with an anti-TMEM16A antibody, an anti-MUC5AC antibody and an anti-α-tubulin antibody.

Results: OVA challenge induced an increase in short circuit current within 1 min in the OVA-sensitized tracheas but not in the non-sensitized tracheas, which was inhibited by pretreatment of T16Ainh-A01. Sensitized tracheas showed goblet cell metaplasia with more positive TMEM16A immunostaining, particularly in the apical portion compared with the non-sensitized tracheas. The in vitro UTP-induced increase in Cl ion transport was strongly inhibited by pretreatment with T16Ainh-A01, benzbromarone, and niflumic acid. TMEM16A was positively immunostained at the apical portion and in the MUC5AC-positive area in IL-13-induced goblet cell metaplasia.

Conclusions: Antigen challenge and Ca-dependent agonist treatment increased Cl ion transport via the overexpression of TMEM16A in goblet cell metaplasia in a guinea-pig asthma model. TMEM16A inhibitors may be useful for the treatment of hyper-secretion in asthma.

Keywords: CaCC; Cl channel; IL-13; TMEM16A; animal models; asthma; epithelium; goblet cell; mucus.

MeSH terms

  • Animals
  • Anoctamin-1 / immunology*
  • Asthma / immunology
  • Asthma / metabolism*
  • Cells, Cultured
  • Goblet Cells / immunology
  • Goblet Cells / metabolism
  • Guinea Pigs
  • Ion Transport / immunology*
  • Male


  • Anoctamin-1