Abstract 237 The imprinted gene DLK1 induces a regenerative state in engineered human myocardium

Background: The human heart displays limited potential to recover from injury. Delta-like non-canonical Notch ligand-1 (DLK1) is an imprinted gene strongly expressed during embryo-fetal development. We hypothesized that temporary and localized DLK1 expression by CRISPR/Cas9 gene activation may induce a regenerative state in engineered human myocardium (EHM).

Methods and Results: RNA sequencing of muscle biopsies from non-failing (n=14) and failing (n=12) human hearts demonstrated a reduced expression of DLK1 in heart failure. In addition, serum levels of soluble DLK1 were reduced in patients with heart failure and correlated to left ventricular ejection fraction. Similar to patient samples, DLK1 expression was reduced in EHM with simulated heart failure. To test if DLK1 restoration prevents contractile dysfunction, we made use of a CRISPRa transgenic iPSC cell line, which stably expresses an enzymatic inactive dCas9 complex to specifically increase and modulate DLK1 expression in either cardiomyocytes or stromal cells. RNA sequencing identified a regenerative transcriptome pattern in DLK1a EHM with differential expression of cell motility, extracellular matrix, cell cycle and metabolism-related processes. Additionally, cell-specific activation induced cellular cross talk with rescue of contractile dysfunction by simulated heart failure in DLK1a EHM (Force of contraction: -13±5 % vs -45±5 % in DLK1a vs NT EHM, n=8, p<0.05).

Clin Res Cardiol (2023). https://doi.org/10.1007/s00392-023-02302-4
The imprinted gene DLK1 induces a regenerative state in engineered human myocardium
B. Berecic¹, N. Bader¹, M. Setya¹, A. Rika², E. Schoger¹, E. Buchholz², S. von Haehling², L. Zelarayán¹, C. Dieterich³, K. Toischer², W.-H. Zimmermann¹, M. Tiburcy¹, for the study group: AG31
¹Institut für Pharmakologie und Toxikologie, Universitätsmedizin Göttingen, Göttingen; ²Herzzentrum, Klinik für Kardiologie und Pneumologie, Universitätsmedizin Göttingen, Göttingen; ³Klinik für Innere Med. III, Kardiologie, Angiologie u. Pneumologie, Universitätsklinikum Heidelberg, Heidelberg;
Background: The human heart displays limited potential to recover from injury. Delta-like non-canonical Notch ligand-1 (DLK1) is an imprinted gene strongly expressed during embryo-fetal development. We hypothesized that temporary and localized DLK1 expression by CRISPR/Cas9 gene activation may induce a regenerative state in engineered human myocardium (EHM). Methods and Results: RNA sequencing of muscle biopsies from non-failing (n=14) and failing (n=12) human hearts demonstrated a reduced expression of DLK1 in heart failure. In addition, serum levels of soluble DLK1 were reduced in patients with heart failure and correlated to left ventricular ejection fraction. Similar to patient samples, DLK1 expression was reduced in EHM with simulated heart failure. To test if DLK1 restoration prevents contractile dysfunction, we made use of a CRISPRa transgenic iPSC cell line, which stably expresses an enzymatic inactive dCas9 complex to specifically increase and modulate DLK1 expression in either cardiomyocytes or stromal cells. RNA sequencing identified a regenerative transcriptome pattern in DLK1a EHM with differential expression of cell motility, extracellular matrix, cell cycle and metabolism-related processes. Additionally, cell-specific activation induced cellular cross talk with rescue of contractile dysfunction by simulated heart failure in DLK1a EHM (Force of contraction: -13±5 % vs -45±5 % in DLK1a vs NT EHM, n=8, p<0.05). Conclusion: Reactivation of the developmental gene DLK1 induces a regenerative state and may protect from heart failure.
https://dgk.org/kongress_programme/ht2023/aBS135.html