Impact of genotoxins on cardiovascular differentiation of murine and human stem- and progenitor cells: Relevance of mechanisms of DNA repair and DNA damage response (DDR)

Background: DNA repair and DNA damage response (DDR) mechanisms are key regulators of genetic stability and, in consequence, of survival and death induced by genotoxic agents, including anticancer drugs. Due to their barrier function, endothelial cells are exposed to particularly high concentrations of systemically present toxic substances. We hypothesize that cardiovascular cell types harbor effective DNA damage defense mechanisms to maintain genomic integrity and cardiovascular health. The dose-limiting adverse effect of anthracycline-type anticancer drugs is irreversible cardiotoxicity. The contribution of cardiovascular progenitor cells and differentiated progeny for the pathophysiology of anthracycline-induced cardiac damage is unknown.

Aim: The project aims to characterize the response of murine and human cardiovascular progenitor cells to doxorubicin. Apart from the identification of lineage specific defense mechanisms, the impact of doxorubicin on the differentiation efficacy of the progenitor cells and the functionality of thereof derived differentiated progeny will be analyzed.

Experimental procedure / working programme: The sensitivity of murine embryonic stem cells (mESC) and human induced pluripotent stem cells (hiPSC) and in vitro differentiated progeny (endothelial cells, cardiomyocytes) will be monitored following treatment with doxorubicin and ionizing radiation for control. The formation and repair of DNA damage, cell cycle progression, alterations in gene expression, activation of DDR mechanisms and induction of cell death and senescence will be analyzed in dose and time kinetic analyses employing state of the art methods. Moreover, the influence of anticancer therapeutics as well as pharmacological modifiers of DNA repair/DDR will be investigated regarding their impact on the efficacy of the differentiation process and the functionality of the differentiated progeny. To this end, mRNA and protein expression of cell-type specific markers and prototypical endothelial and cardiomyocyte functions will be analyzed. The project will be accomplished in close cooperation with other members of the GRK 2578.

Recent publications:

1. Hennicke, T. et al. mESC-based in vitro differentiation models to study vascular response and functionality following genotoxic insults. Toxicol Sci 144, 138-150, doi:10.1093/toxsci/kfu264 (2015).
2. Henninger, C. et al. Distinct contribution of Rac1 expression in cardiomyocytes to anthracycline-induced cardiac injury. Biochem Pharmacol 164, 82-93, doi:10.1016/j.bcp.2019.03.038 (2019).
3. Ohlig, J. et al. Rac1-mediated cardiac damage causes diastolic dysfunction in a mouse model of subacute doxorubicin-induced cardiotoxicity. Arch Toxicol 92, 441-453, doi:10.1007/s00204-017-2017-7 (2018).
4. Jahn, S. K. et al. Distinct influence of the anthracycline derivative doxorubicin on the differentiation efficacy of mESC-derived endothelial progenitor cells. Biochim Biophys Acta Mol Cell Res 1867, 118711, doi:10.1016/j.bbamcr.2020.118711 (2020).
5. Huelsenbeck, J. et al. Inhibition of Rac1 signaling by lovastatin protects against anthracycline-induced cardiac toxicity. Cell Death Dis 2, e190, doi:10.1038/cddis.2011.65 (2011).