Brain Natriuretic Peptide Protects against Hyperresponsiveness of Human Asthmatic Airway Smooth Muscle via an Epithelial Cell-Dependent Mechanism

TY - JOUR

T1 - Brain Natriuretic Peptide Protects against Hyperresponsiveness of Human Asthmatic Airway Smooth Muscle via an Epithelial Cell-Dependent Mechanism

AU - Calzetta, Luigino

AU - Passeri, Daniela

AU - Kanabar, Varsha

AU - Rogliani, Paola

AU - Page, Clive

AU - Cazzola, Mario

AU - Matera, Maria Gabriella

AU - Orlandi, Augusto

PY - 2014/3

Y1 - 2014/3

N2 - Brain natriuretic peptide (BNP) relaxes airways by activating natriuretic peptide receptor-A and elevating cyclic guanosine monophosphate. BNP is more effective in passively sensitized human bronchi compared with control airways. The molecular and cellular patterns involved in this signaling are unknown. The aim of this study was to investigate the influence of BNP on airway smooth muscle (ASM) cells obtained from donors with asthma and healthy donors and to identify the mechanisms involved in BNP-mediated relaxation. The contractile response ofASMcells was microscopically assessed in vitro in the presence of 1 mM BNP or with supernatant from human bronchial epithelial (BEAS-2B) cells pretreated with 1 mM BNP. We investigated the role of muscarinic M2 receptors and inducible nitric oxide synthase (iNOS), quantified the release of acetylcholine and nitric oxide (NO), and assessed the gene/protein expression of iNOS and myosin phosphatase target subunit 1 (MYPT1). Supernatant from BEAS-2B cells treated with BNP reduced the hyperreactivity of asthmatic ASM cells by shifting the potency of histamine by 1.19-fold but had no effect in healthy ASM cells. BNP was not effective directly on ASM cells. Blocking muscarinic M2-receptors and iNOS abolished the protective role of supernatant from BEAS-2B treated with BNP. BNP stimulated the release of acetylcholine (210.7 +/- 11.1%) from BEAS-2B cells that in turn increased MYPT1 and iNOS gene/protein expression and enhanced NO levels in asthmatic ASM supernatant (35.0 +/- 13.0%). This study provides evidence that BNP protects against bronchial hyperresponsiveness via an interaction between respiratory epithelium and ASM in subjects with asthma.

AB - Brain natriuretic peptide (BNP) relaxes airways by activating natriuretic peptide receptor-A and elevating cyclic guanosine monophosphate. BNP is more effective in passively sensitized human bronchi compared with control airways. The molecular and cellular patterns involved in this signaling are unknown. The aim of this study was to investigate the influence of BNP on airway smooth muscle (ASM) cells obtained from donors with asthma and healthy donors and to identify the mechanisms involved in BNP-mediated relaxation. The contractile response ofASMcells was microscopically assessed in vitro in the presence of 1 mM BNP or with supernatant from human bronchial epithelial (BEAS-2B) cells pretreated with 1 mM BNP. We investigated the role of muscarinic M2 receptors and inducible nitric oxide synthase (iNOS), quantified the release of acetylcholine and nitric oxide (NO), and assessed the gene/protein expression of iNOS and myosin phosphatase target subunit 1 (MYPT1). Supernatant from BEAS-2B cells treated with BNP reduced the hyperreactivity of asthmatic ASM cells by shifting the potency of histamine by 1.19-fold but had no effect in healthy ASM cells. BNP was not effective directly on ASM cells. Blocking muscarinic M2-receptors and iNOS abolished the protective role of supernatant from BEAS-2B treated with BNP. BNP stimulated the release of acetylcholine (210.7 +/- 11.1%) from BEAS-2B cells that in turn increased MYPT1 and iNOS gene/protein expression and enhanced NO levels in asthmatic ASM supernatant (35.0 +/- 13.0%). This study provides evidence that BNP protects against bronchial hyperresponsiveness via an interaction between respiratory epithelium and ASM in subjects with asthma.

KW - brain natriuretic peptide

KW - bronchial hyperresponsiveness

KW - airway smooth muscle

KW - airway epithelium

KW - nitric oxide

KW - NITRIC-OXIDE

KW - NEUTRAL ENDOPEPTIDASE

KW - CHOLINERGIC SYSTEM

KW - RELAXANT ACTIVITY

KW - HEART-FAILURE

KW - RECEPTOR

KW - BRONCHODILATOR

KW - TIOTROPIUM

KW - ACETYLCHOLINE

KW - LOCALIZATION

U2 - 10.1165/rcmb.2013-0119OC

DO - 10.1165/rcmb.2013-0119OC

M3 - Article

SN - 1044-1549

VL - 50

SP - 493

EP - 501

JO - American Journal of Respiratory Cell and Molecular Biology

JF - American Journal of Respiratory Cell and Molecular Biology

IS - 3

M1 - N/A

ER -