4-(5-benzo(1-3)dioxol-5-yl-4-pyridin-2-yl-1h-imidazol-2-yl)benzamide and Endomyocardial-Fibrosis

Cytokine-like 1 (Cytl1) is a secreted protein that is involved in diverse biological processes. A comparative modeling study indicated that Cytl1 is structurally and functionally similar to monocyte chemoattractant protein 1 (MCP-1). As MCP-1 plays an important role in cardiac fibrosis (CF) and heart failure (HF), we investigated the role of Cytl1 in a mouse model of CF and HF. Cytl1 was upregulated in the failing mouse heart. Pressure overload-induced CF was significantly attenuated in cytl1 knock-out (KO) mice compared to that from wild-type (WT) mice. By contrast, adeno-associated virus (AAV)-mediated overexpression of cytl1 alone led to the development of CF in vivo. The endothelial-mesenchymal transition (EndMT) and the transdifferentiation of fibroblasts (FBs) to myofibroblasts (MFBs) have been suggested to contribute considerably to CF. Adenovirus-mediated overexpression of cytl1 was sufficient to induce these two critical CF-related processes in vitro, which were completely abrogated by co-treatment with SB-431542, an antagonist of TGF-β receptor 1. Cytl1 induced the expression of TGF-β2 both in vivo and in vitro. Antagonizing the receptor for MCP-1, C-C chemokine receptor type 2 (CCR2), with CAS 445479-97-0 did not block the pro-fibrotic activity of Cytl1 in vitro. Collectively, our data suggest that Cytl1 plays an essential role in CF likely through activating the TGF-β-SMAD signaling pathway. Although the receptor for Cyt1l remains to be identified, Cytl1 provides a novel platform for the development of anti-CF therapies.

Topics: Animals; Aorta; Benzamides; Cell Transdifferentiation; Constriction, Pathologic; Dioxoles; Disease Models, Animal; Endomyocardial Fibrosis; Fibroblasts; Gene Expression Regulation; Heart Failure; Humans; Male; Mice; Mice, Knockout; Myocardial Infarction; Myocardial Reperfusion Injury; Myofibroblasts; Protein Serine-Threonine Kinases; Receptor, Transforming Growth Factor-beta Type I; Receptors, CCR2; Receptors, Cytokine; Receptors, Transforming Growth Factor beta; Signal Transduction; Smad Proteins; Transforming Growth Factor beta2