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Modeling anthracycline-induced cardiotoxicity with patient-specific iPSCs

dc.contributor.advisorStreckfuß-Bömeke, Katrin Dr.
dc.contributor.authorHaupt, Luis Peter
dc.date.accessioned2018-04-17T09:35:36Z
dc.date.available2018-04-17T09:35:36Z
dc.date.issued2018-04-17
dc.identifier.urihttp://hdl.handle.net/11858/00-1735-0000-002E-E3BD-3
dc.identifier.urihttp://dx.doi.org/10.53846/goediss-6834
dc.language.isoengde
dc.rights.urihttp://creativecommons.org/licenses/by-nc-nd/4.0/
dc.subject.ddc570de
dc.titleModeling anthracycline-induced cardiotoxicity with patient-specific iPSCsde
dc.typedoctoralThesisde
dc.contributor.refereeHoyer-Fender, Sigrid Prof. Dr.
dc.date.examination2018-02-20
dc.description.abstractengThe anthracycline doxorubicin (DOX), one of the most effective chemotherapeutic drugs for the treatment of various cancers, is limited in its clinical applications due to cumulative dose-dependent cardiotoxicity. The mechanisms of anthracycline-induced cardiotoxicity (ACT) and potential risk factors are still not fully understood. There is good evidence that the pathophysiology of ACT is multifactorial. Increased production of reactive oxygen species (ROS), topoisomerase II poisoning, disturbances in calcium signaling and sarcomere disarray are discussed as key pathomechanisms of ACT in cardiomyocytes. Recent studies suggest that single nucleotide polymorphisms (SNPs) in genes encoding for NADPH oxidase subunits are associated with the risk to develop ACT. In this study, we aimed to establish a human model of ACT. For this purpose, we used human induced pluripotent stem cells (hiPSCs) as a powerful means to analyze the cardiac phenotype of ACT and to investigate potential genetic risk factors. Integration-free hiPSCs were generated from five patients who were treated with DOX as part of chemotherapy. Three patients with SNPs in the NADPH oxidase subunits RAC2 and p22phox developed ACT. Two patients without these SNPs did not develop ACT and were used as controls (Ctrl). The generated hiPSCs met criteria for pluripotency and were directly differentiated into cardiomyocytes (iPSC-CMs) with high purity. We analyzed the expression of NADPH oxidase subunits, generation of ROS, calcium homeostasis, apoptosis, sarcomeric integrity and mechanical functionality in Ctrl- and ACT-iPSC-CMs on the basal level and upon DOX application. We found a dose-dependent increase of oxidative stress upon DOX treatment in Ctrl- and ACT-iPSC-CMs using Amplex Red and genetically encoded sensors Grx1-roGFP2 and roGFP2-Orp1. The amount of ROS was significantly higher in ACT-iPSC-CMs upon treatment with 0.5 μM DOX. Furthermore, DOX application caused disturbances in iPSC-CM calcium transients in both groups. Low and high DOX concentrations had contradicting effects on calcium transients indicating a biphasic mechanism. DOX application resulted in a significantly higher increase of apoptosis in ACT-iPSC-CMs compared to Ctrl-iPSC-CMs. Furthermore, the sarcomeric integrity was significantly decreased in ACT-iPSC-CMs but not in Ctrl-iPSC-CMs upon treatment with clinically relevant DOX concentrations. Engineered heart muscles (EHMs) were generated from Ctrl- and ACT-iPSC-CMs to analyze mechanical functionality. DOX application caused an increase in EHM beating frequency and arrhythmia in both groups. Importantly, the maximal force of contraction decreased more in ACT-EHMs than in Ctrl-EHMs upon DOX application. Taken together, we established a human iPSC-CM-based model of ACT that recapitulates critical pathomechanisms. Our findings indicate that the genetic background of chemotherapy patients determines the risk to develop ACT. In the future, the generated iPSC-CM ACT model may be used to analyze the mechanisms of ACT in a human cardiac context, to screen and develop cardioprotectants and to find new biomarkers of ACT.de
dc.contributor.coRefereeLutz, Susanne Prof. Dr.
dc.subject.enganthracycline-induced cardiotoxicityde
dc.subject.engiPSCsde
dc.identifier.urnurn:nbn:de:gbv:7-11858/00-1735-0000-002E-E3BD-3-7
dc.affiliation.instituteBiologische Fakultät für Biologie und Psychologiede
dc.subject.gokfullBiologie (PPN619462639)de
dc.identifier.ppn1018941924


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