TRAF3IP2 mediates TWEAK/TWEAKR-induced pro-fibrotic responses in cultured cardiac fibroblasts and the heart

Abstract

Persistent inflammation promotes development and progression of heart failure (HF). TWEAK (TNF-Related WEAK Inducer Of Apoptosis), a NF-κB- and/or AP-1-responsive proinflammatory cytokine that signals via TWEAK receptor (TWEAKR), is expressed at high levels in human and preclinical models of HF. Since the adapter molecule TRAF3IP2 (TRAF3 Interacting Protein 2) is an upstream regulator of various proinflammatory pathways, including those activated by NF-κB and AP-1, we hypothesized that targeting TRAF3IP2 inhibits TWEAK-induced proinflammatory and pro-fibrotic responses in vitro and in vivo. Consistent with the hypothesis, forced expression of TRAF3IP2 upregulated TWEAK and its receptor expression in cultured adult mouse cardiac fibroblasts (CF). Further, exogenous TWEAK upregulated TRAF3IP2 expression in a time- and dose-dependent manner, suggesting a positive-feedback regulation of TRAF3IP2 and TWEAK. TWEAK also promoted TRAF3IP2 nuclear translocation. Confirming its critical role in TWEAK signaling, silencing TRAF3IP2 inhibited TWEAK autoregulation, TWEAKR upregulation, p38 MAPK, NF-κB and AP-1 activation, inflammatory cytokine expression, MMP and TIMP1 activation, collagen expression and secretion, and importantly, proliferation and migration. Recapitulating these in vitro results, continuous infusion of TWEAK for 7 days increased systolic blood pressure (SBP), upregulated TRAF3IP2 expression, activated p38 MAPK, NF-κB and AP-1, induced the expression of multiple proinflammatory and pro-fibrotic mediators, and interstitial fibrosis in hearts of wild type mice. These proinflammatory and pro-fibrotic changes occurred in conjunction with myocardial hypertrophy and contractile dysfunction. Importantly, genetic ablation of TRAF3IP2 inhibited these TWEAK-induced adverse cardiac changes independent of increases in SBP, indicating that TRAF3IP2 plays a causal role, and thus a therapeutic target, in chronic inflammatory and fibro-proliferative diseases.

The use of leukocytes’ secretome to individually target biological therapy in autoimmune arthritis: a case report

“…However, the use of these cells often requires invasive techniques to obtain them and their purification, for subsequent activation, is more labour-intensive than blood cells [27]. It is also useful to stress that the presence of a SNP in TRAF3IP2 rs33980500, as shown in this case report, should be present in all cell types using this signalling pathway [28,29].…”

RECK suppresses interleukin‐17/TRAF3IP2‐mediated MMP‐13 activation and human aortic smooth muscle cell migration and proliferation

“…After 48 hr, the medium was removed and the plates were frozen at −80°C for 2 hr before assay. Plates were then thawed, stained with CyQUANT GR dye according to manufacturer's protocol (Molecular Probes, Eugene, OR), and read on a FL x 800 microplate fluorescence reader (Bio‐Tek Instruments, Winooski, VT) using 485/20 excitation and 528/20 emission filters, and analyzed using KC 4 software (Bio‐Tek Instruments; Das et al, ). To determine the role of TRAF3IP2, miRs, inhibitors, or inducers on proliferation, SMC was treated as detailed in figure legends before the addition of IL‐17A or recombinant human MMP‐13.…”

Tumor Necrosis Factor-Like Weak Inducer of Apoptosis (TWEAK)/Fibroblast Growth Factor-Inducible 14 (Fn14) Axis in Cardiovascular Diseases: Progress and Challenges

“…Furthermore, treatment of rat cardiomyocytes with rTWEAK also promotes an inflammatory response via NF-kB nuclear translocation and subsequent activation of its regulated-genes, CCL2 and CCL5 [30]. In the same way, in vivo systemic administration of recombinant TWEAK during 7 days, activates the same signaling pathways than in vitro, triggers interstitial fibrosis, increases systolic blood pressure (SBP) and produces contractile dysfunction in mice hearts [96]. Genetic depletion of TRAF3IP2 inhibits TWEAK-induced adverse cardiac effects in mice [96].…”

“…In the same way, in vivo systemic administration of recombinant TWEAK during 7 days, activates the same signaling pathways than in vitro, triggers interstitial fibrosis, increases systolic blood pressure (SBP) and produces contractile dysfunction in mice hearts [96]. Genetic depletion of TRAF3IP2 inhibits TWEAK-induced adverse cardiac effects in mice [96]. The mechanism by which TWEAK induces cardiomyocyte dysfunction could be related with proliferator-activated receptor gamma coactivator-1α (PGC1 α), a gene required for mitochondrial oxidative phosphorylation.…”

“…Myocardial remodeling is characterized not only by alterations of the cardiomyocyte but also by changes in the interstitial cells and matrix [3]. rTWEAK increases cytokine synthesis and collagen expression in cardiac fibroblast by TRAF3IP2 expression, p38 MAPK, NF-kB, and AP-1 activation [96]. Furthermore, treatment of rat cardiomyocytes with rTWEAK also promotes an inflammatory response via NF-kB nuclear translocation and subsequent activation of its regulated-genes, CCL2 and CCL5 [30].…”