title: Combined effects of interleukin-1α and transforming growth factor-β1 on modulation of human cardiac fibroblast function.
abstract: During cardiac remodeling, cardiac fibroblasts (CF) are influenced by increased levels of interleukin-1α (IL-1α) and transforming growth factor-β1 (TGFβ1). The present study investigated the interaction between these two important cytokines on function of human CF and their differentiation to myofibroblasts (CMF). CF were isolated from human atrial appendage and exposed to IL-1α and/or TGFβ1 (both 0.1 ng/ml). mRNA expression levels of selected genes were determined after 6-24h by real-time RT-PCR, while protein levels were analyzed at 24-48 h by ELISA or western blot. Activation of canonical signaling pathways (NFκB, Smad3, p38 MAPK) was determined by western blotting. Differentiation to CMF was examined by collagen gel contraction assays. Exposure of CF to IL-1α alone enhanced levels of IL-6, IL-8, matrix metalloproteinase-3 (MMP3) and collagen III (COL3A1), but reduced the CMF markers α-smooth muscle actin (αSMA) and connective tissue growth factor (CTGF/CCN2). By contrast, TGFβ1 alone had minor effects on IL-6, IL-8 and MMP3 levels, but significantly increased levels of the CMF markers αSMA, CTGF, COL1A1 and COL3A1. Co-stimulation with both IL-1α and TGFβ1 increased MMP3 expression synergistically. Furthermore, while TGFβ1 had no effect on IL-1α-induced IL-6 or IL-8 levels, co-stimulation inhibited the TGFβ1-induced increase in αSMA and blocked the gel contraction caused by TGFβ1. Combining IL-1α and TGFβ1 had no apparent effect on their canonical signaling pathways. In conclusion, IL-1α and TGFβ1 act synergistically to stimulate MMP3 expression in CF. Moreover, IL-1α has a dominant inhibitory effect on the phenotypic switch of CF to CMF induced by TGFβ1.
authors.affiliation: Department of Physiology, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands. Electronic address: f.vannieuwenhoven@maastrichtuniversity.nl.
authors.forename: Frans A
authors.initials: FA
authors.lastname: van Nieuwenhoven
authors.forename: Karen E
authors.initials: KE
authors.lastname: Hemmings
authors.forename: Karen E
authors.initials: KE
authors.lastname: Porter
authors.forename: Neil A
authors.initials: NA
authors.lastname: Turner
mesh_terms: D015153:Blotting, Western; D024061:Collagen Type III / Q000378:metabolism; D005347:Fibroblasts / Q000378:metabolism / Q000502:physiology*; D005786:Gene Expression Regulation / Q000235:genetics*; D006801:Humans; D053582:Interleukin-1alpha / Q000235:genetics / Q000378:metabolism*; D015850:Interleukin-6 / Q000378:metabolism; D016209:Interleukin-8 / Q000378:metabolism; D019278:Matrix Metalloproteinase 3 / Q000378:metabolism; D009206:Myocardium / Q000166:cytology* / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000502:physiology*; D053773:Transforming Growth Factor beta1 / Q000235:genetics / Q000378:metabolism*
chemical_list: C439971:COL3A1 protein, human; D024061:Collagen Type III; D053582:Interleukin-1alpha; D015850:Interleukin-6; D016209:Interleukin-8; D053773:Transforming Growth Factor beta1; C511768:MMP3 protein, human; D019278:Matrix Metalloproteinase 3
keywords: CF; CMF; COL1A1; COL3A1; CTGF; Cardiac fibroblasts; Cytokines; ECM; Extracellular matrix; Fibrosis; IL; Inflammation; MMP; Remodeling; TGFβ1; TNFα; alpha-smooth muscle actin; cardiac fibroblast; cardiac myofibroblast; collagen I; collagen III; connective tissue growth factor; extracellular matrix; interleukin; matrix metalloproteinase; transforming growth factor β1; tumor necrosis factor α; αSMA