CysLT1 receptor-induced human airway smooth muscle cells proliferation requires ROS generation, EGF receptor transactivation and ERK1/2 phosphorylation

Autor: Barbara Viviani, Valérie Capra, G. Enrico Rovati, Simona Citro, Saula Ravasi
Jazyk: angličtina
Rok vydání: 2006
Předmět:
Pulmonary and Respiratory Medicine
Transcriptional Activation
medicine.medical_specialty
Morpholines
Myocytes
Smooth Muscle
Bronchi
Biology
Pertussis toxin
Leukotriene D4
Transactivation
Internal medicine
medicine
Humans
Enzyme Inhibitors
Phosphorylation
Asthma
leukotriene
smooth muscle cells
remodeling
transactivation
ROS
EGF
ERK1/2
Extracellular Signal-Regulated MAP Kinases
Protein Kinase Inhibitors
PI3K/AKT/mTOR pathway
Cells
Cultured
Cell Proliferation
Mitogen-Activated Protein Kinase 1
Receptors
Leukotriene
lcsh:RC705-779
Mitogen-Activated Protein Kinase 3
Research
Receptor transactivation
Membrane Proteins
Smooth muscle contraction
DNA
Free Radical Scavengers
lcsh:Diseases of the respiratory system
respiratory system
Cell biology
Acetylcysteine
Androstadienes
Enzyme Activation
ErbB Receptors
Endocrinology
Pertussis Toxin
Chromones
Settore BIO/14 - Farmacologia
ras Proteins
Signal transduction
Reactive Oxygen Species
Wortmannin
Proto-oncogene tyrosine-protein kinase Src
Zdroj: Respiratory Research, Vol 7, Iss 1, p 42 (2006)
Respiratory Research
ISSN: 1465-9921
Popis: Background Cysteine-containing leukotrienes (cysteinyl-LTs) are pivotal inflammatory mediators that play important roles in the pathophysiology of asthma, allergic rhinitis, and other inflammatory conditions. In particular, cysteinyl-LTs exert a variety of effects with relevance to the aetiology of asthma such as smooth muscle contraction, eosinophil recruitment, increased microvascular permeability, enhanced mucus secretion and decreased mucus transport and, finally, airway smooth muscle cells (ASMC) proliferation. We used human ASMC (HASMC) to identify the signal transduction pathway(s) of the leukotriene D4 (LTD4)-induced DNA synthesis. Methods Proliferation of primary HASMC was measured by [3H]thymidine incorporation. Phosphorylation of EGF receptor (EGF-R) and ERK1/2 was assessed with a polyclonal anti-EGF-R or anti-phosphoERKl/2 monoclonal antibody. A Ras pull-down assay kit was used to evaluate Ras activation. The production of reactive oxygen species (ROS) was estimated by measuring dichlorodihydrofluorescein (DCF) oxidation. Results We demonstrate that in HASMC LTD4-stimulated thymidine incorporation and potentiation of EGF-induced mitogenic signaling mostly depends upon EGF-R transactivation through the stimulation of CysLT1-R. Accordingly, we found that LTD4 stimulation was able to trigger the increase of Ras-GTP and, in turn, to activate ERK1/2. We show here that EGF-R transactivation was sensitive to pertussis toxin (PTX) and phosphoinositide 3-kinase (PI3K) inhibitors and that it occurred independently from Src activity, despite the observation of a strong impairment of LTD4-induced DNA synthesis following Src inhibition. More interestingly, CysLT1-R stimulation increased the production of ROS and N-acetylcysteine (NAC) abolished LTD4-induced EGF-R phosphorylation and thymidine incorporation. Conclusion Collectively, our data demonstrate that in HASMC LTD4 stimulation of a Gi/o coupled CysLT1-R triggers the transactivation of the EGF-R through the intervention of PI3K and ROS. While PI3K and ROS involvement is an early event, the activation of Src occurs downstream of EGF-R activation and is followed by the classical Ras-ERK1/2 signaling pathway to control G1 progression and cell proliferation.
Databáze: OpenAIRE
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