title: The stellate vascular smooth muscle cell phenotype is induced by IL-1β via the secretion of PGE2 and subsequent cAMP-dependent protein kinase A activation.
abstract: Atherosclerosis development is associated with morphological changes to intimal cells, leading to a stellate cell phenotype. In this study, we aimed to determine whether and how key pro-atherogenic cytokines present in atherosclerotic plaques (IL-1β, TNFα and IFNγ) could induce this phenotype, as these molecules are known to trigger the transdifferentiation of vascular smooth muscle cells (VSMCs). We found that, IL-1β was the only major inflammatory mediator tested capable of inducing a stellate morphology in VSMCs. This finding was confirmed by staining for F-actin and vinculin at focal adhesions, as these two markers were disrupted only by IL-1β. We then investigated the possible association of this IL-1β-dependent change in morphology with an increase in intracellular cAMP concentration ([cAMP]), using the FRET-based biosensor for cAMP (T)Epac(VV). Experiments in the presence of IL-1β or medium conditioned by IL-1β-treated VSMCs and pharmacological tools demonstrated that the long-term increase in intracellular cAMP concentration was induced by the secretion of an autocrine/paracrine mediator, prostaglandin E₂(PGE₂), acting through the EP4 receptor. Finally, by knocking down the expression of the regulatory subunit PKAR1α, thereby reproducing the effects of IL-1β and PGE₂ on VSMCs, we demonstrated the contribution of PKA activity to the observed behavior of VSMCs.
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06CNRS UMR 8256 B2A, IBPS, F-75005, Paris, France.
authors.forename: Karl
authors.initials: K
authors.lastname: Blirando
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06CNRS UMR 8256 B2A, IBPS, F-75005, Paris, France.
authors.forename: Régis
authors.initials: R
authors.lastname: Blaise
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06CNRS UMR 8256 B2A, IBPS, F-75005, Paris, France.
authors.forename: Natalia
authors.initials: N
authors.lastname: Gorodnaya
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06CNRS UMR 8256 B2A, IBPS, F-75005, Paris, France.
authors.forename: Clotilde
authors.initials: C
authors.lastname: Rouxel
authors.affiliation: Inserm U1188 Diabète Athérothrombose Thérapies Réunion Océan Indien (DéTROI) CYROI, 2, rue Maxime Rivière, 97490 Sainte Clotilde, La Réunion, France.
authors.forename: Olivier
authors.initials: O
authors.lastname: Meilhac
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06CNRS UMR 8256 B2A, IBPS, F-75005, Paris, France.
authors.forename: Pierre
authors.initials: P
authors.lastname: Vincent
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06CNRS UMR 8256 B2A, IBPS, F-75005, Paris, France. Electronic address: isabelle.limon@upmc.fr.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Limon
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D000242:Cyclic AMP / Q000378:metabolism; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism*; D015232:Dinoprostone / Q000378:metabolism; D004789:Enzyme Activation; D053583:Interleukin-1beta / Q000378:metabolism*; D009131:Muscle, Smooth, Vascular / Q000166:cytology* / Q000201:enzymology / Q000378:metabolism; D051381:Rats
chemical_list: D053583:Interleukin-1beta; D000242:Cyclic AMP; D017868:Cyclic AMP-Dependent Protein Kinases; D015232:Dinoprostone
keywords: IL-1β; PGE(2); PKA; Vascular smooth muscle cells; cAMP; stellate cell morphology