AIMS

Projects A05 and A06 from the first funding period are now merged into a single project A06, due to their overlapping interests and complementing expertise. In the second funding period, we have 3 main aims (Figure 1). First, we will investigate whether cytoplasmic granule formation is a potential disease driver beyond RBM20’s loss-of-splicing. Second, we will characterize the composition of these granules, both on protein and RNA level, and investigate how these granules affect protein production. Finally, we will examine how fibroblasts, immune cells, and other non-cardiomyocytes contribute to disease development and progression.

a06 graphic 2 - Unraveling the molecular mechanisms of RBM20 cardiomyopathy

Figure 1.

Findings: 1st funding period

During first funding period, we identified two central mechanisms of RBM20 cardiomyopathy. First, excessive CAMK2D activation drives cardiac dysfunction, and its inhibition alleviates the disease in mouse models (see ending project A05). Second, disease-causing RBM20 RS-domain variants weaken interactions with the nuclear importer TNPO3, leading to cytoplasmic RBM20 granules. Enhancing TNPO3-mediated nuclear import restored RBM20 localization and splicing, and improved cardiac function in vivo, revealing a promising therapeutic strategy (Figure 2). A large-scale pooled localization screen identified all possible cytoplasmic mislocalization variants including the known RS-domain variants, as well as unknown variants outside this hotspot (Figure 2). However, especially in the RRM domain even correctly localized variants showed a splicing defect. These findings open up a new DCM pathomechanism independent of mislocalization.

Figure 2.

SELECTED SCIENTIFIC OUTCOMES

2026

Kornienko J, Müller LH, Nickel A, Kohlhaas M, Börmel M, Alfonso-Gonzalez C, Oorschot VMJ, Fungate M, Lewey S, Kees J, Müller J, Lindenhofer D, Fenzl K, Schraft L, Clauder-Münster S, Konrad L, Haberkant P, Montoya FDM, Dauksaite V, Gotthardt M, van den Hoogenhof MMG, Maack C, Steinmetz LM.

Circulation. 2026 Sep 15.

2025

Pant P HY, Ghouse Z, Bai F, Kemmling E, Konrad L, Kistler R, Seeger T, Gotthardt M, Parikh VN & van den Hoogenhof MMG.

medRxiv. 2025.

2025

Kornienko, J., Schraft, L., Fenzl, K., van den Hoogenhof, MMG, Steinmetz, LM.

Circulation. 2025, 152(10), 739.

2025

van den Hoogenhof MM, Duran J, Britto-Borges T, Kemmling E, Konrad L, Lennermann DC, Hartmann J, Schraft L, Kornienko J, Bock T, Krüger M, Dieterich C, Steinmetz LM, Dewenter M & Backs J.

bioRxiv. 2025.05.23.655557, 2025.

2023

Kornienko, J., Rodríguez-Martínez, M., Fenzl, K., Hinze, F., Schraivogel, D., Grosch, M., Tunaj, B., Lindenhofer, D., Schraft, L., Kueblbeck, M., Smith, E., Mao, C., Brown, E., Owens, A., Saguner, AM, Meder, B., Parikh, V., Gotthardt, M., & Steinmetz, LM.

Nature communications. 2023, 14, 4312.

2023

Grosch M, Schraft L, Chan A, Kuchenhoff L, Rapti K, Ferreira AM, Kornienko J, Li S, Radke MH, Kramer C, Clauder-Munster S, Perlas E, Backs J, Gotthardt M, Dieterich C, van den Hoogenhof MMG, Grimm D & Steinmetz LM.

Nat Commun. 14:3714, 2023.

2022

Lennermann DC, Pepin ME, Grosch M, Konrad L, Kemmling E, Hartmann J, Nolte JL, Clauder-Munster S, Kayvanpour E, Sedaghat-Hamedani F, Haas J, Meder B, van den Boogaard M, Amin AS, Dewenter M, Kruger M, Steinmetz LM, Backs J & van den Hoogenhof MMG.

Am J Physiol Heart Circ Physiol. 323:H1296-H310, 2022.

Scientific Staff

Iuliia Kornienko
Kai Fenzl
Anastasiia Korosteleva
Linda Müller

© EMBL Marietta Schupp
© Tobias Schwerdt, Max Delbrück Center