@article{KarnatiSeimetzKleefeldtetal.2021, author = {Karnati, Srikanth and Seimetz, Michael and Kleefeldt, Florian and Sonawane, Avinash and Madhusudhan, Thati and Bachhuka, Akash and Kosanovic, Djuro and Weissmann, Norbert and Kr{\"u}ger, Karsten and Erg{\"u}n, S{\"u}leyman}, title = {Chronic Obstructive Pulmonary Disease and the Cardiovascular System: Vascular Repair and Regeneration as a Therapeutic Target}, series = {Frontiers in Cardiovascular Medicine}, volume = {8}, journal = {Frontiers in Cardiovascular Medicine}, issn = {2297-055X}, doi = {10.3389/fcvm.2021.649512}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-235631}, year = {2021}, abstract = {Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity and mortality worldwide and encompasses chronic bronchitis and emphysema. It has been shown that vascular wall remodeling and pulmonary hypertension (PH) can occur not only in patients with COPD but also in smokers with normal lung function, suggesting a causal role for vascular alterations in the development of emphysema. Mechanistically, abnormalities in the vasculature, such as inflammation, endothelial dysfunction, imbalances in cellular apoptosis/proliferation, and increased oxidative/nitrosative stress promote development of PH, cor pulmonale, and most probably pulmonary emphysema. Hypoxemia in the pulmonary chamber modulates the activation of key transcription factors and signaling cascades, which propagates inflammation and infiltration of neutrophils, resulting in vascular remodeling. Endothelial progenitor cells have angiogenesis capabilities, resulting in transdifferentiation of the smooth muscle cells via aberrant activation of several cytokines, growth factors, and chemokines. The vascular endothelium influences the balance between vaso-constriction and -dilation in the heart. Targeting key players affecting the vasculature might help in the development of new treatment strategies for both PH and COPD. The present review aims to summarize current knowledge about vascular alterations and production of reactive oxygen species in COPD. The present review emphasizes on the importance of the vasculature for the usually parenchyma-focused view of the pathobiology of COPD.}, language = {en} } @article{UpcinHenkeKleefeldtetal.2021, author = {Upcin, Berin and Henke, Erik and Kleefeldt, Florian and Hoffmann, Helene and Rosenwald, Andreas and Irmak-Sav, Ster and Aktas, Huseyin Bertal and R{\"u}ckschloß, Uwe and Erg{\"u}n, S{\"u}leyman}, title = {Contribution of adventitia-derived stem and progenitor cells to new vessel formation in tumors}, series = {Cells}, volume = {10}, journal = {Cells}, number = {7}, doi = {10.3390/cells10071719}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-242577}, year = {2021}, abstract = {Blocking tumor vascularization has not yet come to fruition to the extent it was hoped for, as angiogenesis inhibitors have shown only partial success in the clinic. We hypothesized that under- appreciated vascular wall-resident stem and progenitor cells (VW-SPCs) might be involved in tumor vascularization and influence effectiveness of anti-angiogenic therapy. Indeed, in patient samples, we observed that vascular adventitia-resident CD34\(^+\) VW-SPCs are recruited to tumors in situ from co-opted vessels. To elucidate this in detail, we established an ex vivo model using concomitant embedding of multi-cellular tumor spheroids (MCTS) and mouse aortic rings (ARs) into collagen gels, similar to the so-called aortic ring assay (ARA). Moreover, ARA was modified by removing the ARs' adventitia that harbors VW-SPCs. Thus, this model enabled distinguishing the contribution of VW-SPCs from that of mature endothelial cells (ECs) to new vessel formation. Our results show that the formation of capillary-like sprouts is considerably delayed, and their number and network formation were significantly reduced by removing the adventitia. Substituting iPSC-derived neural spheroids for MCTS resulted in distinct sprouting patterns that were also strongly influenced by the presence or absence of VW-SPCs, also underlying the involvement of these cells in non-pathological vascularization. Our data suggest that more comprehensive approaches are needed in order to block all of the mechanisms contributing to tumor vascularization.}, language = {en} }