Translation of Angiotensin-Converting Enzyme 2 upon Liver- and Lung-Targeted Delivery of Optimized Chemically Modified mRNA

Schrom, Eva; Huber, Maja; Aneja, Manish; Dohmen, Christian; Emrich, Daniela; Geiger, Johannes; Hasenpusch, Günther; Herrmann-Janson, Annika; Kretzschmann, Verena; Mykhailyk, Olga; Pasewald, Tamara; Oak, Prajakta; Hilgendorff, Anne; Wohlleber, Dirk; Hoymann, Heinz-Gerd; Schaudien, Dirk; Plank, Christian; Rudolph, Carsten; Kubisch-Dohmen, Rebekka

ing today a repertoire of techniques for designing chemically modified mRNA (cmRNA) with tailor-made pharmacodynamic properties. [27] [28] [29] [30] [31] However, clinical application of RTT is still at a pre-clinical stage, owing to challenges such as cell-or organ-specific delivery or the complexity of mRNA pharmacology. 26 As previously stated, promising results of ACE2 therapy in experimental liver and lung fibrosis have been reported. [14] [15] [16] [17] [21] [22] [23] In human clinical trials, the safety and tolerability of systemically applied recombinant ACE2 was shown. 32, 33 However, localized translation of membrane-anchored ACE2 may be even more favorable. This may be achieved with recent advances in cmRNA technology. [34] [35] [36] Therefore, the objective of this study was to establish robust ACE2 translation from cmRNA in the liver or lung, respectively. First, we performed an in vitro validation of ACE2 cmRNA translation, protein activity, and integrity. In a second step, we designed eight different cmRNA sequences and screened them in cell culture to identify the optimal cmRNA composition for sustained protein translation and activity in liver and lung cells. Finally, this lead candidate was formulated for liver-or lung-specific delivery, which led to increased translation of ACE2 protein selectively in these organs.