A Photoswitchable Ligand Targeting the β1 -Adrenoceptor Enables Light-Control of the Cardiac Rhythm

Catecholamine-triggered β-adrenoceptor (β-AR) signaling is essential for the correct functioning of the heart. Although both β1 - and β2 -AR subtypes are expressed in cardiomyocytes, drugs selectively targeting β1 -AR have proven this receptor as the main target for the therapeutic effects of beta blockers in the heart. Here, we report a new strategy for the light-control of β1 -AR activation by means of photoswitchable drugs with a high level of β1 -/β2 -AR selectivity. All reported molecules allow for an efficient real-time optical control of receptor function in vitro. Moreover, using confocal microscopy we demonstrate that the binding of our best hit, pAzo-2, can be reversibly photocontrolled. Strikingly, pAzo-2 also enables a dynamic cardiac rhythm management on living zebrafish larvae using light, thus highlighting the therapeutic and research potential of the developed photoswitches. Overall, this work provides the first proof of precise control of the therapeutic target β1 -AR in native environments using light.We thank Ignacio Pérez (IQAC-CSIC, Barcelona), Yolanda Pérez (IQAC-CSIC, Barcelona), Lourdes Muñoz (SimChem, IQAC-CSIC, Barcelona) and Carme Serra (SimChem, IQAC-CSIC, Barcelona) for technical support. We thank Diana Baxter (Institute for Research in Biomedicine, IRB, Barcelona) for her thorough revision of the language of this manuscript. We thank Dr. Kees Jalink (The Netherlands Cancer Institute, Amsterdam, the Netherlands) for providing the plasmids encoding for the Epac-SH188 biosensor. We thank the University of Vic-Central University of Catalonia (UVic-UCC) and Dr. Marta Otero for the material assignment which helped in some biological assays. We thank Nikos Hatzakis for access to the Olympus IX81 confocal microscope (UCPH, DK). This work was supported by ERDF-FEDER European Fund and Ministerio de Ciencia e Innovación, Agencia Estatal de Investigación (projects CTQ2017-89222-R and PID2020-120499RB-I00) and by the Catalan government (2017 SGR 1604) to A.L. X.R. research was financed by the Spanish Ministry of Economy, Industry and Competitiveness (SAF2015-74132-JIN). D.R. research was supported by “Agencia Estatal de Investigación” from the Spanish Ministry of Science and Innovation (project PID2020-113371RB-C21) and IDAEA-CSIC, Severo Ochoa Centre of Excellence (CEX2018-000794-S), which financed M.F. A.D.C. received the support of a fellowship from “la Caixa” Foundation (ID 100010434) under the fellowship code LCF/BQ/DE18/11670012. K.L.M., A.D. and Y.M. were supported by the Novo Nordisk Foundation (NNF20OC0064565).Peer reviewe