Single-nuclear transcriptome profiling identifies persistent fibroblast activation in hypertrophic and failing human hearts of patients with longstanding disease
Badder Kattih, Felicitas Boeckling, Mariana Shumliakivska, Lukas Tombor, Tina Rasper, Katja Schmitz, Jedrzej Hoffmann, Luka Nicin, Wesley T Abplanalp, Daniel C Carstens, Mani Arsalan, Fabian Emrich, Tomas Holubec, Thomas Walther, Valentina O Puntmann, Eike Nagel, David John, Andreas M Zeiher, Stefanie Dimmeler- Physiology (medical)
- Cardiology and Cardiovascular Medicine
- Physiology
Abstract
Aims
Cardiac fibrosis drives the progression of heart failure in ischemic and hypertrophic cardiomyopathy. Therefore, the development of specific antifibrotic treatment regimens to counteract cardiac fibrosis is of high clinical relevance. Hence, this study examined the presence of persistent fibroblast activation during longstanding human heart disease at a single-cell resolution to identify putative therapeutic targets to counteract pathological cardiac fibrosis in patients.
Methods and results
We used single nuclei RNA sequencing with human tissues from 2 samples of one healthy donor, 5 hypertrophic and 2 failing hearts. Unsupervised sub-clustering of 7,110 nuclei led to the identification of 7 distinct fibroblast clusters.
Deconvolution of cardiac fibroblast heterogeneity revealed a distinct population of human cardiac fibroblasts with a molecular signature of persistent fibroblast activation and a transcriptional switch towards a profibrotic extracellular matrix composition in patients with established cardiac hypertrophy and heart failure. This subcluster was characterized by high expression of POSTN, RUNX1, CILP and a target gene AEBP1 (all p < 0.001). Strikingly, elevated circulating AEBP1 blood level were also detected in a validation cohort of patients with confirmed cardiac fibrosis and hypertrophic cardiomyopathy by cardiac magnetic resonance imaging (p < 0.01). Since endogenous AEBP1 expression was increased in patients with established cardiac hypertrophy and heart failure, we assessed the functional consequence of siRNA mediated AEBP1 silencing in human cardiac fibroblasts. Indeed, AEBP1 silencing reduced proliferation, migration, as well as fibroblast contractile capacity and α-SMA gene expression, which is a hallmark of fibroblast activation (all p < 0.05). Mechanistically, the antifibrotic effects of AEBP1 silencing were linked to TGFβ pathway modulation.
Conclusion
Together, this study identifies persistent fibroblast activation in patients with longstanding heart disease, which might be detected by circulating AEBP1 and therapeutically modulated by its targeted silencing in human cardiac fibroblasts.