Combined effects of interleukin-1α and transforming growth factor-β1 on modulation of human cardiac fibroblast function

Abstract

A C C E P T E D M A N U S C R I P T ACCEPTED MANUSCRIPT AbstractDuring 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 6-24 h by real-time RT-PCR, while protein levels were analyzed at 24-48 h by ELISA or Western blot.Activation of canonical signaling pathways (NFB, 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 MMP3levels, 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.

Investigating inherent functional differences between human cardiac fibroblasts cultured from nondiabetic and Type 2 diabetic donors

“…h, in agreement with our recent report [30], but there was no difference between T2DM and ND CF (Fig. 3D).…”

“…Specifically, we investigated expression of the proinflammatory cytokines IL1 , IL6 and IL8, the genes that we have previously studied in this cell type [23,[28][29][30].…”

Cardiac Fibroblast Activation Post-Myocardial Infarction: Current Knowledge Gaps

“…IL-1α/β, TGF-β1, and fibronectin) [44]. The Turner lab has demonstrated that stimulating human cardiac fibroblasts to IL-1α upregulates the expression of IL-6, IL-8, MMP-3, and collagen III and downregulates α-SMA and CTGF [81]. In comparison, TGF-β1 significantly elevates α-SMA, CTGF, collagen1α1 and collagen3α1 expression, with minor effects on IL-6, IL-8, and MMP-3.…”

Human cardiac fibroblasts adaptive responses to controlled combined mechanical strain and oxygen changes in vitro

“…Within this range and in line with previous in vitro observations of CFs behavior (Ugolini et al, 2016), we selected 2% strain as indicative of reduced contractility and 8% strain as representative of full myocardial contractility. These environmental changes and the following initial cellular responses happen in a timeframe of hours, as shown in vitro (van Nieuwenhoven et al, 2013; Turner et al, 2007, 2009) as well as in vivo (Guillén et al, 1995; Morishita et al, 2015). We thus performed experiments lasting 24 hr and evaluated the main early aspects that govern fibrotic responses in the injured myocardium: ECM remodeling, with stainings for collagen I and quantifications of MMP expression; proliferation of CFs, with analyses of mitotic cells, Hippo pathway signaling and mitogenic PDGF (platelet-derived growth factor) expression; secretion of inflammatory and pro-fibrotic cytokines in CF supernatants; myofibroblast differentiation, through stainings for αSMA (α-smooth muscle actin).…”