ABSTRACTS – ORAL PRESENTATIONS - AMCA, spol. s r.o.

h induced very minor manifestations of apoptosis, including morphological changes,
release of cytochrome c from mitochondria, stimulation of caspase 3-like activity, and
cleavage of poly (ADP-ribose) polymerase (PARP). However, in a combined treatment with
cisplatin and 100 µM TTFA a strong increase of the drug-induced toxicity was observed,
whereas TTFA by itself did not cause any toxicity. Measuring mitochondrially produced
ROS with a superoxide-sensitive dye that is specifically targeted to the mitochondria,
revealed a strong induction of ROS by TTFA in combination with cisplatin. Antioxidant
N-acetyl-cysteine (NAC) partially reversed the stimulatory effect of TTFA on cisplatininduced
apoptosis. Both results clearly demonstrate the importance of ROS produced by
complex II for cellular response to anticancer treatment.
Another inhibitor of complex II, methyl-malonate, failed to stimulate cisplatin-induced
apoptosis. Interestingly, both drugs convey their effect by inhibiting different subunits
of the succinate dehydrogenase complex, indicating an importance of the activity of
individual subunits for the sensitivity of cells to drug induced cell death.
P16. INTERACTION OF MYELOPEROXIDASE WITH ENDOTHELIAL CELLS
Hana Kolářová 1,2 , Jan Víteček 1,2 , Silvie Kremserová 1,3 , Anna Klinke 4 , Stephan Baldus 4 ,
Lukáš Kubala 1,2
1
Institute of Biophysics, Academy of Sciences of the Czech Republic;
2
International Clinical Research Center - Center of Biomolecular and Cellular
Engineering, St. Anne‘s University Hospital Brno, Brno, Czech Republic;
3
Department of Animal Physiology, Faculty of Science, Masaryk University, Czech
Republic;
4
Heart Center, University of Cologne, Cologne, Germany
Activation of polymorphonuclear neutrophils (PMN) and release of myeloperoxidase
(MPO), expressed in large amounts in PMN, are suggested to be important in the vascular
inflammatory processes. It was shown that MPO can bind to vascular endothelium and
undergo transcytosis. However, the importance of the interaction of highly cationic MPO
with glycocalyx on endothelial surface layer, which is composed of glycosaminoglycans
(GAGs) and proteoglycans, for the glycocalyx integrity and function has not been
described. Herein we focused on characterization of MPO interaction with selected GAGs
and proteins that can be found in extracellular matrix produced by vascular endothelium.
We show that MPO binds to the ECM proteins collagen IV and fibronectin, and
this association is enhanced by the pre-incubation of these proteins with GAGs.
Correspondingly, an excess of GAGs in solution during incubation inhibits the binding of
MPO to collagen IV and fibronectin. These observations were confirmed with cell-derived
ECM. The oxidizing and chlorinating potential of MPO was preserved upon binding to
collagen IV and fibronectin; even the potentiation of MPO activity in the presence of
collagen IV and fibronectin was observed.
Further, we aimed to characterize to which extent MPO modulates the charge and the
three dimensional structure of the glycocalyx. The hypothesis of the project assumes
106 Analytical Cytometry VII