mAChRs activation induces epithelial-mesenchymal transition on lung epithelial cells

Abstract

BackgroundEpithelial-mesenchymal transition (EMT) has been proposed as a mechanism in the progression of airway diseases and cancer. Here, we explored the role of acetylcholine (ACh) and the pathway involved in the process of EMT, as well as the effects of mAChRs antagonist.MethodsHuman lung epithelial cells were stimulated with carbachol, an analogue of ACh, and epithelial and mesenchymal marker proteins were evaluated using western blot and immunofluorescence analyses.ResultsDecreased E-cadherin expression and increased vimentin and α-SMA expression induced by TGF-β1 in alveolar epithelial cell (A549) were significantly abrogated by the non-selective mAChR antagonist atropine and enhanced by the acetylcholinesterase inhibitor physostigmine. An EMT event also occurred in response to physostigmine alone. Furthermore, ChAT express and ACh release by A549 cells were enhanced by TGF-β1. Interestingly, ACh analogue carbachol also induced EMT in A549 cells as well as in bronchial epithelial cells (16HBE) in a time- and concentration-dependent manner, the induction of carbachol was abrogated by selective antagonist of M1 (pirenzepine) and M3 (4-DAMP) mAChRs, but not by M2 (methoctramine) antagonist. Moreover, carbachol induced TGF-β1 production from A549 cells concomitantly with the EMT process. Carbachol-induced EMT occurred through phosphorylation of Smad2/3 and ERK, which was inhibited by pirenzepine and 4-DAMP.ConclusionsOur findings for the first time indicated that mAChR activation, perhaps via M1 and M3 mAChR, induced lung epithelial cells to undergo EMT and provided insights into novel therapeutic strategies for airway diseases in which lung remodeling occurs.

The effects of substance P and acetylcholine on human tenocyte proliferation converge mechanistically via TGF-β1

“…Furthermore, inhibition of the NK-1R and mAChRs, resulted in the downregulation of TGF-β1 expression. This finding is consistent with previous reports in other cell types that both ACh and SP can independently induce TGF-β1 expression via their respective receptors [9, 10]. …”

Airway epithelial barrier dysfunction in the pathogenesis and prognosis of respiratory tract diseases in childhood and adulthood

“…37 EMT could be inhibited by muscarinic antagonists. 102 Despite available treatment options such as intranasal steroids (INS), antihistamines, leukotriene receptor antagonists, and immunotherapy, 20% of patients with AR do not respond favorably to treatment. 52 In the complex interaction between human nasal epithelial cells and environmental pathogens, host factors play an important role in the severity and progression of disease and response to pharmacologic therapies.…”

The Role of Epithelial-Mesenchymal Transition in Chronic Obstructive Pulmonary Disease

“…Inhibition of PDE4 (phosphodiesterase 4) with roflumilast inhibits EMT changes in epithelial cells taken from COPD patients [Milara et al, 2014]. Other receptors unrelated to TGF-β have also been shown to be upregulated during COPD, including acetylcholine receptors acting through the Rac1 pathway [Yang et al, 2014]. Urokinase activity and the presence of urokinase plasminogen activation receptors were also shown to be related to EMT changes and may provide another potential target pathway [Wang et al, , 2015.…”