Fibroblasts are a diverse group of stromal cells that not only provide structural support but also actively regulate extracellular matrix production and remodelling. As such, fibroblasts preserve tissue architecture, influence mechanical properties and cell to cell communication through the release of cytokines and growth factors (1). Historically, studying fibroblast biology has been challenging due to the absence of definitive lineage markers and phenotypic plasticity across organs. However, recent technological advances, including lineage-tracing models, single-cell RNA sequencing, and spatial omics, have transformed this field, revealing that fibroblasts comprise multiple phenotypically and functionally distinct populations with specialized roles in both physiological repair and pathological diseases (2).
In their recent authoritative review, Van Linthout et al. (3) present a comprehensive overview of cardiac fibroblast biology by integrating these emerging single-cell and spatial datasets. Their review positions cardiac fibroblasts as drivers of myocardial remodelling following injury, emphasizing that fibrosis, creates ventricular stiffness, heightens arrhythmia risk and worsens clinical outcomes across diverse cardiac injuries. Specifically, the authors highlight the capacity of fibroblasts to synthesize mechanical, inflammatory, and metabolic signals, thereby directing fibrosis toward either resolution or persistent maladaptation. In doing so, they establish a framework for distinguishing adaptive from maladaptive fibrotic remodelling in patients through emphasising fibroblast heterogeneity, identifying proliferative and myofibroblast populations. Notably, key regulatory pathways, including TGF β, BRD4 mediated transcription, YAP/TAZ mechanotransduction and MBNL1 controlled RNA processing, emerge as promising therapeutic targets.
Beyond fibroblast heterogeneity, the authors also emphasize the role of fibroblasts in immune modulation. Fibroblast-mediated immune signalling links inflammation to fibrosis progression, positioning fibroblasts as potential therapeutic entry points to rebalance maladaptive immune responses following myocardial injury and in heart failure. Furthermore, pathological crosstalk between fibroblasts, cardiomyocytes and endothelial cells contributes to impaired myocardial contractility, arrhythmogenesis and microvascular dysfunction, highlighting the importance of therapeutic strategies that consider the multicellular nature of cardiac remodelling.Towards this end, the authors discuss fibroblast-targeted therapeutic approaches. Innovative strategies such as gene therapy, CAR-T–based targeting and inhibition of mechanosensitive signalling pathways offer promising avenues to overcome the limitations of current non-selective anti-fibrotic treatments. In addition, the identification of fibroblast-specific biomarkers and the development of advanced imaging strategies will be critical for monitoring fibrosis dynamics, guiding therapy selection, and assessing disease progression in patients with heart failure.
Together, this valuable work outlines a roadmap toward fibroblast-focused medicine in cardiovascular disease, illustrating how deeper mechanistic insight into fibroblast heterogeneity and signalling could translate into more effective therapies for fibrotic heart disease.