CC Chemokines in Myocardial Fibrosis: Regulatory Networks of CCL17 and Emerging Therapeutic Implications

Myocardial fibrosis is a key pathological process driving the progression of cardiovascular diseases toward heart failure, closely linked to persistent inflammation and immune dysregulation. Among CC chemokines, CCL17 has emerged as an important mediator connecting immune cell dynamics with fibrotic remodeling. This review outlines current understanding of the cellular sources, regulatory mechanisms, and functional roles of CCL17, with particular attention to its impact on regulatory T cell (Treg) recruitment through ligand-biased signaling. Beyond this mechanism, CCL17 likely operates within a broader inflammatory network, with potential interactions involving CCR2+ macrophages and IL-17-related pathways. Experimental studies show that disruption of CCL17 signaling attenuates fibrosis and improves cardiac function, while clinical data link elevated circulating CCL17 to cardiac dysfunction and adverse outcomes. However, the absence of clinical trials and the redundancy of chemokine networks remain key challenges for translation. Overall, CCL17 may serve as a biomarker and therapeutic target, although its clinical application will require a more integrated, network-based understanding.