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- ItemNeutrophil extracellular trap formation is elicited in response to cold physical plasma(Hoboken, NJ : Wiley, 2016) Bekeschus, Sander; Winterbourn, VChristine C.; Kolata, Julia; Masur, Kai; Hasse, Sybille; Bröker, Barbara M.; Parker, Heather A.Cold physical plasma is an ionized gas with a multitude of components, including hydrogen peroxide and other reactive oxygen and nitrogen species. Recent studies suggest that exposure of wounds to cold plasma may accelerate healing. Upon wounding, neutrophils are the first line of defense against invading microorganisms but have also been identified to play a role in delayed healing. In this study, we examined how plasma treatment affects the functions of peripheral blood neutrophils. Plasma treatment induced oxidative stress, as assessed by the oxidation of intracellular fluorescent redox probes; reduced metabolic activity; but did not induce early apoptosis. Neutrophil oxidative burst was only modestly affected after plasma treatment, and the killing of Pseudomonas aeruginosa and Staphylococcus aureus was not significantly affected. Intriguingly, we found that plasma induced profound extracellular trap formation. This was inhibited by the presence of catalase during plasma treatment but was not replicated by adding an equivalent concentration of hydrogen peroxide. Plasma-induced neutrophil extracellular trap formation was not dependent on the activity of myeloperoxidase or NADPH oxidase 2 but seemed to involve short-lived molecules. The amount of DNA release and the time course after plasma treatment were similar to that with the common neutrophil extracellular trap inducer PMA. After neutrophil extracellular traps had formed, concentrations of IL-8 were also significantly increased in supernatants of plasma-treated neutrophils. Both neutrophil extracellular traps and IL-8 release may aid antimicrobial activity and spur inflammation at the wound site. Whether this aids or exacerbates wound healing needs to be tested.
- ItemNon-thermal plasma treatment induces MAPK signaling in human monocytes(Berlin : de Gruyter, 2014) Bundscherer, Lena; Nagel, Stefanie; Hasse, Sybille; Tresp, Helena; Wende, Kristian; Walther, Reinhard; Reuter, Stephan; Weltmann, Klaus-Dieter; Masur, Kai; Lindequist, UlrikeThe application of non-thermal atmospheric pressure plasma raises a hope for the new wound healing strategies. Next to its antibacterial effect it is known to stimulate skin cells. However, monocytes are also needed for the complex process of a wound healing. This study investigates the impact of plasma on the intracellular signaling events in the primary human monocytes. The proliferative MEK-ERK (MAPK/ERK kinase-extracellular signal-regulated kinase) pathway was activated by short plasma treatment times. In contrast, an induction of the apoptotic JNK (c-Jun N-terminal kinase) cascade as well as activation of caspase 3 were observed after long plasma exposure. These findings indicate that monocytes can be differentially stimulated by plasma treatment and may contribute to the proper wound recovery.