Neuronal chemorepellent Semaphorin 3E inhibits human airway smooth muscle cell proliferation and migration.
BACKGROUND
Chronic airway diseases, including asthma, are characterized by increased airway smooth muscle (ASM) mass that is due in part to growth factor-mediated ASM cell proliferation and migration. However, the molecular mechanisms underlying these effects are not completely understood. Semaphorin 3E (Sema3E) has emerged as an essential mediator involved in cell migration, proliferation, and angiogenesis, although its role in ASM cell function is not investigated.


OBJECTIVE
We sought to determine the expression of Sema3E receptor, plexinD1, in human ASM cells (HASMCs); effect of Sema3E on basal and platelet-derived growth factor (PDGF)-induced proliferation and migration; and underlying signaling pathways.


METHODS
Expression of plexinD1 in HASMCs was studied with RT-PCR, immunostaining, and flow cytometry. The effect of Sema3E on HASMC proliferation and migration was evaluated by 5-ethynyl-2'-deoxyuridine (EdU) incorporation, cell count, and Boyden chamber assay. Sema3E-mediated intracellular signaling was investigated with fluorescent microscopy, flow cytometry, Rac1 activation, and Western blot analysis.


RESULTS
HASMCs from healthy persons expressed plexinD1 more than HASMCs from asthmatic patients. Sema3E increased plexinD1 expression in HASMCs from asthmatic patients. Recombinant Sema3E inhibited PDGF-mediated HASMC proliferation and migration, which was associated with F-actin depolymerization, suppression of PDGF-induced Rac1 guanosine triphosphatase activity, and Akt and extracellular signal-regulated kinase 1 and 2 phosphorylation. Bronchial biopsies from patients with mild asthma displayed immunoreactivity of plexinD1, suggesting the potential in vivo role of Sema3E-PlexinD1 axis in HASMC function.


CONCLUSIONS
This study provides the first evidence that Sema3E receptor is expressed and plays functional roles in HASMCs. Our data suggest a regulatory role of Sema3E in PDGF-mediated proliferation and migration, leading to downregulation of ASM remodeling.
Department of Immunology, University of Manitoba, Winnipeg, Manitoba, Canada.
Hesam
H
Movassagh
Department of Immunology, University of Manitoba, Winnipeg, Manitoba, Canada.
Lianyu
L
Shan
Department of Physiology, University of Manitoba, Winnipeg, Manitoba, Canada.
Andrew J
AJ
Halayko
University Hospital Basel, University of Basel, Basel, Switzerland.
Michael
M
Roth
University Hospital Basel, University of Basel, Basel, Switzerland.
Michael
M
Tamm
Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie du Quebec, Université Laval, Quebec City, Quebec, Canada.
Jamila
J
Chakir
Department of Immunology, University of Manitoba, Winnipeg, Manitoba, Canada. Electronic address: gounni@cc.umanitoba.ca.
Abdelilah S
AS
Gounni
D000328:Adult; D056151:Airway Remodeling / Q000502:physiology*; D001249:Asthma / Q000473:pathology* / Q000503:physiopathology; D000077214:Becaplermin; D001980:Bronchi / Q000166:cytology; D015816:Cell Adhesion Molecules, Neuronal / Q000502:physiology; D002465:Cell Movement; D049109:Cell Proliferation; D002478:Cells, Cultured; D005260:Female; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D008297:Male; D008562:Membrane Glycoproteins; D032389:Myocytes, Smooth Muscle / Q000473:pathology / Q000502:physiology*; D020574:Proto-Oncogene Proteins c-sis / Q000494:pharmacology; D039961:Semaphorins / Q000502:physiology*; D014132:Trachea / Q000166:cytology; D055815:Young Adult
D015816:Cell Adhesion Molecules, Neuronal; D047908:Intracellular Signaling Peptides and Proteins; D008562:Membrane Glycoproteins; C493082:PLXND1 protein, human; D020574:Proto-Oncogene Proteins c-sis; C494123:SEMA3E protein, human; D039961:Semaphorins; D000077214:Becaplermin
5-Ethynyl-2′-deoxyuridine; ASM; Airway smooth muscle; Airway smooth muscle cell; EGF; ERK; EdU; Epidermal growth factor; Extracellular signal-regulated kinase; FACS; Fluorescence-activated cell sorting; GTPase; Guanosine triphosphatase; HASMC; Human airway smooth muscle cell; MAPK; MFI; Mean fluorescence intensity; Mitogen-activated protein kinase; PDGF; PI3K; Phosphatidylinositol 3-kinase; Platelet-derived growth factor; Rac1; Ras-related C3 botulinum toxin substrate 1; Sema3E; Semaphorin 3E; VEGFR2; Vascular endothelial growth factor receptor 2; migration; platelet-derived growth factor; plexinD1; proliferation; semaphorin 3E