Enhancing KLF15 activity in cardiomyocytes: a novel approach to prevent pathological reprogramming and fibrosis via nuclease-deficient dCas9VPR
Summary
Transcriptional activity perturbation holds promise for selectively modulating harmful transcriptional networks, but its therapeutic potential remains largely unexplored. We employed a network-based analysis of single-cell heart transcriptomes to identify transcription factor activities linked to pathological cardiomyocytes in vivo. This analysis revealed that transcriptional activity of Krüppel-like factor 15 (KLF15) exhibited the most significant change in pathological cardiomyocytes, characterized by less effective repression of disease-associated genes in stressed hearts, which correlated with reduced KLF15 expression. To restore KLF15 activity, we utilized CRISPR/nuclease-dead (d)Cas9-based transcriptional enhancement (CRISPRa) in cardiomyocytes, which effectively abolished fetal reprogramming by simultaneously suppressing pathological gene expression and restoring metabolic homeostasis under sustained stress conditions. Furthermore, we identified a novel cell-nonautonomous anti-fibrotic effect mediated by cardiomyocyte-fibroblast crosstalk, and revealed the contribution of KLF15-dependent Alpha-2-glycoprotein 1, zinc-binding (AZGP1) regulation in this process. We also elucidated the upstream mechanisms of KLF15 regulation, highlighting its role as a cell-specific downstream target of the broad TGF-β canonical signaling pathway, along with its downstream-dependent mechanisms in human cardiomyocytes. Finally, to enhance the therapeutic potential of this approach, we engineered and validated an adeno-associated viral (AAV) vector with a small CRISPRa system for endogenous regulation in human cardiomyocytes suitable for clinical applications. Overall, we elucidated a regulatory circuit involving TGF-β, KLF15, and AZGP1, which coordinates critical pathological responses through cellular crosstalk between cardiomyocytes and fibroblasts. Importantly, we demonstrated the efficacy of CRISPRa as an epigenetic intervention restoring a critical transcriptional function disrupted in non-genetic heart failure. This approach provides a promising blueprint for future adaptation targeting additional non-hereditary pathologies. © 2026. The Author(s).
| Authors | Schoger E, Kim R, Bleckwedel F, Peralta T, Priesmeier L, Fischer J, Stengel L, Rocha C, Santos GL, Lutz S, Boileau E, Baumgarten N, Schulz MH, Dieterich C, Müller OJ, Cyganek L, Cabrera-Orefice A, Eberl H, Maack C, Streckfuss-Bömeke K, Pavez-Giani M, Doroudgar S, Sossalla ST, Zelarayán LC |
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| Journal | Signal transduction and targeted therapy |
| Publication Date | 2026 Mar 3;11(1) |
| PubMed | 41771837 |
| PubMed Central | PMC12953643 |
| DOI | 10.1038/s41392-026-02593-9 |