Nanomagneto-assisted diagnosis and therapy of cardiac arrhythmias
Zusammenfassung der Projektergebnisse
Our aim was to establish novel strategies for the analysis and treatment of cardiac arrhythmias using magnetic nanoparticles (MNP) and confined magnetic fields. Inherited or drug-induced long QT syndromes can lead to tachyarrhythmias. These disorders could be potentially better explored and/or even treated taking advantage of human induced pluripotent stem cells (hiPSC)-derived cardiomyocytes and novel screening approaches. We have therefore tested enhancement of hiPSC-cardiac differentiation using MNP-aided mRNA transfer of Baf60C, Gata4, Mef2c and Mesp1. Although MNP-mRNA coupling yielded very high expression efficacies in hiPSC, augmented cardiac differentiation was not achieved most likely because of the use of an already very effective differentiation protocol. To analyze the modulation of the electrophysiological properties of hiPSC-derived cardiomyocytes, we developed MNP-based cell positioning on multi-well micro electrode arrays (MEA). This enabled the recording of field potentials from many wells in parallel and this technology is therefore suited for automatized scalable drug screening in vitro. Bradycardic arrhythmias are mostly due to a dysfunction of the sinoatrial- or atrio-ventricular nodes and currently treated by implantation of electrical pacemakers. However, these devices have limitations and we have therefore tried as an alternative to generate biological as well as optical pacemakers in vitro and also in vivo taking advantage of MNP-aided viral gene transfer of optogenetic proteins or pacemaker ion channels. First, we established an analysis platform for long term recording of spontaneous cardiomyocyte beating in vitro and automatic identification of pacemaker location. Then we tested the different pacemaking molecules and found that MNP-aided local expression of the pacemaker channels HCN2, HCN4, a transdominant negative version of Kir2.1 or the transcription factor Tbx18 did not yield consistent de novo pacemakers. In clear contrast, the optogenetic cation channel Channelrhodopsin2 (ChR2) and the light-sensitive Gq-coupled receptor Melanopsin turned out to reliably induce and/or modulate pacing by local illumination. This approach also worked in vivo after virus-based gene transfer of ChR2 enabling effective optogenetic pacing and even defibrillation of ventricular arrhythmias.
Projektbezogene Publikationen (Auswahl)
-
Local gene targeting and cell positioning using magnetic nanoparticles and magnetic tips: Comparison of mathematical simulations with experiments. Pharm. Res. 2012; 29:1380-91
Kilgus C., Heidsieck A., Ottersbach A., Roell W., Trueck C., Fleischmann B.K., Gleich B., Sasse P.
-
Modeling long QT syndromes using induced pluripotent stem cells: current progress and future challenges. Trends Cardiovasc Med. 2013; 23:91-
Friedrichs S, Malan D, Sasse P
-
Optogenetic activation of Gq signalling modulates pacemaker activity of cardiomyocytes. Cardiovasc Res. 2014; 102:507-16
Beiert T, Bruegmann T, Sasse P
-
Scalable Electrophysiological Investigation of iPS Cell- Derived Cardiomyocytes Obtained by a Lentiviral Purification Strategy. J Clin Med. 2015; 4:102-23
Friedrichs S, Malan D, Voss Y, Sasse P
-
Systemic gene transfer enables optogenetic pacing of mouse hearts. Cardiovasc Res. 2015; 106:338-43
Vogt CC, Bruegmann T, Malan D, Ottersbach A, Roell W, Fleischmann BK, Sasse P
-
Optogenetic defibrillation terminates ventricular arrhythmia in mouse hearts and human simulations. J. Clin. Invest. 2016
Bruegmann T, Boyle PM, Vogt CC, Karathanos T, Arevalo HJ, Fleischmann BK, Trayanova NA, Sasse P
-
Vascular Repair by Circumferential Cell Therapy Using Magnetic Nanoparticles and Tailored Magnets. ACS Nano. 2016;10:369-76
Vosen S, Rieck S, Heidsieck A, Mykhaylyk O, Zimmermann K, Bloch W, Eberbeck D, Plank C, Gleich B, Pfeifer A, Fleischmann BK, Wenzel D
