Airway epithelial cells regulate membrane potential, neurotransmission and muscle tone of the dog airway smooth muscle.

The increased mass of airway smooth muscle (ASM) in the airways of asthmatic patients may contribute to the pathology of this disease by increasing the capacity for airway narrowing. Evidence for the airway epithelium as a participant in ASM remodeling is accruing. To investigate mechanisms by which airway epithelial cells induce ASM cell (ASMC) proliferation, we have employed a co-culture model to explore markers of ASMC proliferative phenotype. Co-culture with epithelial cells led to incorporation of bromodeoxyuridine into ASMCs, indicating augmented proliferation and an associated increase in mRNA of the pro-proliferative co-transcription factor Elk1. Although the mitogen heparin-binding epidermal growth factor (HB-EGF) was augmented in the co-culture supernatant, the ASMC epidermal growth factor receptor (EGFR), an effector of HB-EGF induced proliferation, did not mediate epithelial-induced proliferation. The co-culture increased the expression of ASMC mRNA for the pro-inflammatory cytokines IL-6 and IL-8 as well as the pro-proliferative microRNA miR-210. The transcriptional repressor Max-binding protein (Mnt), a putative target of miR-210, was transcriptionally repressed in co-cultured ASMCs. Together, these data indicate that the airway epithelium-induced proliferative phenotype of ASMCs is not driven by EGFR signaling, but rather may be dependent on miR210 targeting of tumor suppressor Mnt.

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Pro-inflammatory mediators increase levels of the noncoding RNA GAS5 in airway smooth muscle and epithelial cells

Canadian Journal of Physiology and Pharmacology ◽

10.1139/cjpp-2014-0391 ◽

2015 ◽

Vol 93 (3) ◽

pp. 203-206 ◽

Cited By ~ 28

Author(s):

Christine R. Keenan ◽

Michael J. Schuliga ◽

Alastair G. Stewart

Keyword(s):

Smooth Muscle ◽

Epithelial Cells ◽

Airway Smooth Muscle ◽

Inflammatory Mediators ◽

Noncoding Rna ◽

Cell Types ◽

Airway Epithelial Cells ◽

Airway Epithelial ◽

Structural Cell ◽

Glucocorticoid Sensitivity

The long noncoding RNA (lncRNA) GAS5 has been found to act as a decoy for the glucocorticoid receptor (GR), thus implicating GAS5 as a potential regulator of glucocorticoid sensitivity and resistance. Airway smooth muscle (ASM) cells and airway epithelial cells (AEC) play an important role in the pathogenesis and persistence of asthma and other chronic airways diseases. These airway structural cell types are also important cellular targets of the anti-inflammatory actions of glucocorticoids. In this study, we sought to examine the relevance of GAS5 to glucocorticoid sensitivity and resistance in ASM and AEC. We provide the first evidence that pro-inflammatory mediators up-regulate GAS5 levels in both airway epithelial and smooth muscle cells, and that decreasing GAS5 levels can enhance glucocorticoid action in AEC.

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Human airway smooth muscle cells secrete amphiregulin via bradykinin/COX-2/PGE2, inducing COX-2, CXCL8, and VEGF expression in airway epithelial cells

AJP Lung Cellular and Molecular Physiology ◽

10.1152/ajplung.00390.2014 ◽

2015 ◽

Vol 309 (3) ◽

pp. L237-L249 ◽

Cited By ~ 19

Author(s):

Karl Deacon ◽

Alan J. Knox

Keyword(s):

Smooth Muscle ◽

Epithelial Cells ◽

Smooth Muscle Cells ◽

Airway Smooth Muscle ◽

Airway Epithelial Cells ◽

Airway Smooth Muscle Cells ◽

Airway Epithelial ◽

Human Airway Smooth Muscle ◽

Cox 2 ◽

Stimulation Of

Human airway smooth muscle cells (HASMC) contribute to asthma pathophysiology through an increased smooth muscle mass and elevated cytokine/chemokine output. Little is known about how HASMC and the airway epithelium interact to regulate chronic airway inflammation and remodeling. Amphiregulin is a member of the family of epidermal growth factor receptor (EGFR) agonists with cell growth and proinflammatory roles and increased expression in the lungs of asthma patients. Here we show that bradykinin (BK) stimulation of HASMC increases amphiregulin secretion in a mechanism dependent on BK-induced COX-2 expression, increased PGE2 output, and the stimulation of HASMC EP2 and EP4 receptors. Conditioned medium from BK treated HASMC induced CXCL8, VEGF, and COX-2 mRNA and protein accumulation in airway epithelial cells, which were blocked by anti-amphiregulin antibodies and amphiregulin siRNA, suggesting a paracrine effect of HASMC-derived amphiregulin on airway epithelial cells. Consistent with this, recombinant amphiregulin induced CXCL8, VEGF, and COX-2 in airway epithelial cells. Finally, we found that conditioned media from amphiregulin-stimulated airway epithelial cells induced amphiregulin expression in HASMC and that this was dependent on airway epithelial cell COX-2 activity. Our study provides evidence of a dynamic axis of interaction between HASMC and epithelial cells that amplifies CXCL8, VEGF, COX-2, and amphiregulin production.

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