In WP1, we have identified novel disease mechanisms of PLN through the measurement of a very large set of proteins and phosphorylation sites of these proteins, namely the formation of aggresomes containing PLN. These findings are currently being validated. Cells from PLN patients with very different disease phenotypes were isolated and cardiomyocytes from these subjects were created. We did not find a decreased contractility of engineered heart tissues carrying the PLN mutation. Instead, we see that these tissues are structurally different, which we are currently investigating further.
In WP2, a series of tools for precise gene editing based on homology directed repair or prime editing, and for RNA delivery to the heart, were developed. Based on high throughput screenings using whole genome miRNA libraries, we have identified miRNAs that selective increase homologous recombination or prime editing in cardiomyocytes. We have also screened over 40 LNP formulations for delivering gene editing RNA suites (Cas9 mRNA, gRNA, adjuvant miRNA) to the heart, in both cultured cardiomyocytes and in vivo.
In WP3, the best PBS/RTT in combination with the most efficient Prime Editor has been selected and optimized in HEK 293 and detected by ddPCR. We have selected best combinations for maximum gene editing efficiency to move forward to testing in iPSC expressing the PLN R14del mutation, to correct the mutation.
In WP4, PLN R14del pigs are available and a PKP pig model is being engineered. A dual AAV9-PE system is currently tested in ex vivo cultured PLN-R14del pig heart slices. In preparation of the in vivo validation of gene editing in PLN-R14del pigs, the breeding program was continued. In collaboration with the UMC, the ex vivo characterization of PLN-R14del pig hearts by a multi-channel EKG in Langendorff-perfusion system was established and the in vivo electrophysiological characterization of the PLN-R14del pigs still continues.
In WP5, workshops on patient-engagement were successfully organized. A multi-Stakeholder Advisory Committee has been established. Needs and concerns of stakeholders are being investigated through survey and interview studies. The legal framework surrounding approval of gene therapies is examined by literature review. This to ensure the GEREMY project adopts the framework of Responsible Research and Innovation (RRI) and IRDiRC in its project design by embedding ethics and social perspectives throughout the lifecycle of the project, with appropriate engagement of relevant stakeholders and a collaboration that is open, inclusive, and responsive to emerging problems. In addition, several successful patient information days have been organized by the PLN Foundation.
In WP6, Kapadi/Exom conducts literature research on the regulatory aspects concerning phase I clinical trials for cardiac gene therapy and orphan drug designation. Additionally, they consult with the consortium to incorporate info and questions within the preclinical scientific work.
In WP7, an intellectual property rights (IPR) plan and a dissemination and exploitation plan were developed. Also, project information and results are continuously shared with the community through various activities, both online and in person.
In WP8, a data management plan was developed. Project progress is managed and reported and a meeting schedule was set up. 3 successful consortium meetings have been organized in which all partners were represented.
