Interleukin-1β Differentially Regulates β2 Adrenoreceptor and Prostaglandin E2-mediated cAMP Accumulation and Chloride Efflux from Calu-3 Bronchial Epithelial Cells

Abstract

Here we tested the effect of interleukin-1␤, a proinflammatory cytokine, on cAMP accumulation and chloride efflux in Calu-3 airway epithelial cells in response to ligands binding to adenylyl cyclase-coupled receptors such as the ␤ 2 adrenoreceptor and EP prostanoid receptors. Interleukin-1␤ significantly increased isoprenaline-induced cAMP accumulation by increasing ␤ 2 adrenoreceptor numbers via a protein kinase A-dependent mechanism. In contrast, interleukin-1␤ significantly impaired prostaglandin E 2 -induced cAMP accumulation by induction of cyclo-oxygenase-2, prostaglandin E 2 production, and a resulting downregulation of adenylyl cyclase. The cAMP changes were all mirrored by alterations in chloride efflux assessed using the fluorescent chloride probe N-(ethoxycarbonylmethyl)-6-methoxyquinolinium bromide with interleukin-1␤ increasing chloride efflux in response to isoprenaline and reducing the response to prostaglandin E 2 . Studies with glibenclamide confirmed that chloride efflux was via the cystic fibrosis transmembrane conductance regulator. Calu-3 expresses EP 4 receptors, but not EP 2 , and receptor expression is reduced by interleukin-1␤. Collectively, these results provide mechanistic insight into how interleukin-1␤ can differentially regulate cAMP generation and chloride efflux in response to different adenylyl cyclase-coupled ligands in the same cell. These findings have important implications for diseases involving inflammation and abnormal ion flux such as cystic fibrosis.

Prostaglandin E2 Regulation of Cystic Fibrosis Transmembrane Conductance Regulator Activity and Airway Surface Liquid Volume Requires Gap Junctional Communication

“…Joy and Cowley, in contrast, reported that Calu-3 cells express all four known EP-R subtypes, but point to EP4-Rs in the regulation of CFTR-dependent iodide efflux (28). Via RT-PCR, we only detected EP4-Rs in our Calu-3 cells, and EP4 inhibition was sufficient to prevent CFTR activation, confirming the results of Clayton and colleagues (29).…”

The cytokines interleukin-1β and tumor necrosis factor-α stimulate CFTR-mediated fluid secretion by swine airway submucosal glands

“…These results contrast with those published in Calu-3 cells, where p38 MAP kinase pathways were involved in IL-1␤-stimulated CFTR-dependent Cl Ϫ currents (14). These results also contrast with previous measurements in Calu-3 cells showing that IL-1␤ affected cAMP and Cl Ϫ permeability differentially when added together with either prostaglandin E2 or isoproterenol (6). The contradictions may result from differences in the transport machinery expressed in Calu-3 compared with the native tissue.…”

Adenosine Regulation of Cystic Fibrosis Transmembrane Conductance Regulator through Prostenoids in Airway Epithelia

“…Eicosanoids with well-described prominent airway/pulmonary effects (related primarily to asthma and airway function) include TXA2, PGD2, PGE2, and PGI2, and many of the accompanying receptors have been described to signal through G s and cAMP. Recent studies suggest that EP2 and EP4 are expressed in Calu-3 cells, where they can activate CFTR, and an inverse regulatory relationship between IL-1␤ and PGE2 has recently been described in airway epithelia (42,43). PGE2, PGF2␣, and to a lesser extent 15-HETE have also been detected on the apical surface of porcine airway cell monolayers, which was augmented after stimulation with calcium-mobilizing agents and AA (44).…”