Annemarie Barton

Impact of non-thermal plasma treatment on MAPK signaling pathways of human immune cell lines.

In the field of wound healing research non-thermal plasma (NTP) increasingly draws attention. Next to its intensely studied antibacterial effects, some studies already showed stimulating effects on eukaryotic cells. This promises a unique potential in healing of chronic wounds, where effective therapies are urgently needed. Immune cells do play an important part in the process of wound healing and their reaction to NTP treatment has yet been rarely examined. Here, we studied the impact of NTP treatment using the kinpen on apoptotic and proliferative cell signaling pathways of two human immune cell lines, the CD4(+)T helper cell line Jurkat and the monocyte cell line THP-1. Depending on NTP treatment time the number of apoptotic cells increased in both investigated cell types according to a caspase 3 assay. Western blot analysis pointed out that plasma treatment activated pro-apoptotic signaling proteins like p38 mitogen-activated protein kinase (p38 MAPK) and c-Jun N-terminal kinase 1 and 2 (JNK 1/2) in both cell types. Stronger signals were detected in Jurkat cells at comparable plasma treatment times. Intriguingly, exposure of Jurkat and THP-1 cells to plasma also activated the pro-proliferative signaling molecules extracellular signal-regulated kinase 1/2 (ERK 1/2) and MAPK/ERK kinase 1 and 2 (MEK 1/2). In contrast to Jurkat cells, the anti-apoptotic heat shock protein 27 (HSP27) was activated in THP-1 cells after plasma treatment, indicating a possible mechanism how THP-1 cells may reduce programmed cell death. In conclusion, several signaling cascades were activated in the examined immune cell lines after NTP treatment and in THP-1 monocytes a possible defense mechanism against plasma impacts could be revealed. Therefore, plasma might be a treatment option for wound healing.

Non-thermal plasma treatment is associated with changes in transcriptome of human epithelial skin cells

Abstract Non-thermal atmospheric pressure plasma has recently gained attention in the field of biomedical and clinical applications. In the area of plasma medicine research, one promising approach is to promote wound healing by stimulation of cells involved. To understand basic molecular and cellular mechanisms triggered by plasma treatment, we investigated biological effects of an argon plasma jet kinpen on human epithelial skin cells. For assessment of transcriptome changes cell culture medium was plasma treated and applied to the HaCaT keratinocyte cell culture (indirect treatment). Consequently, whole-genome microarrays were used to analyze this interaction in detail and identified a statistically significant modification of 3,274 genes including 1,828 up- and 1,446 downregulated genes. Particularly, cells after indirect plasma treatment are characterized by differential expression of a considerable number of genes involved in the response to stress. In this regard, we found a plasma-dependent regulation of oxidative stress answer and increased expression of enzymes of the antioxidative defense system (e.g. 91 oxidoreductases). Our results demonstrate that plasma not only induces cell reactions of stress-sensing but also of proliferative nature. Consistent with gene expression changes as well as Ingenuity Pathway Analysis prediction, we propose that stimulating doses of plasma may protect epithelial skin cells in wound healing by promoting proliferation and differentiation. In conclusion, gene expression profiling may become an important tool in identifying plasma-related changes of gene expression. Our results underline the enormous clinical potential of plasma as a biomedical tool for stimulation of epithelial skin cells.

Atmospheric pressure plasma jet treatment evokes transient oxidative stress in HaCaT keratinocytes and influences cell physiology

Modern non‐thermal atmospheric pressure plasma sources enable controllable interaction with biological systems. Their future applications – e.g. wound management – are based on their unique mixture of reactive components sparking both stimulatory as well as inhibitory processes. To gain detailed understanding of plasma–cell interaction and with respect to risk awareness, key mechanisms need to be identified. This study focuses on the impact of an argon non‐thermal atmospheric pressure plasma jet (kINPen 09) on human HaCaT keratinocytes. With increasing duration, cell viability decreased. In accordance, cells accumulated in G2/M phase within the following 24 h. DNA single‐strand breaks were detected immediately after treatment and receded in the aftermath, returning to control levels after 24 h. No directly plasma‐related DNA double‐strand breaks were detected over the same time. Concurrently, DNA synthesis decreased. Coincident with treatment time, an increase in intracellular 2′,7′‐dichlorodihydrofluorescein diacetate (H2DCFDA) conversion increased reactive oxygen species (ROS) levels. The radical scavenging activity of culture medium crucially influenced these effects. Thus, ROS changed DNA integrity, and the effectiveness of cellular defence mechanisms characterises the interaction of non‐thermal plasma and eukaryotic cells. Effects were time‐dependent, indicating an active response of the eukaryotic cells. Hence, a stimulation of eukaryotic cells using short‐term non‐thermal plasma treatment seems possible, eg in the context of chronic wound care. Long‐term plasma treatments stopped in cell proliferation and apoptosis, which might be relevant in controlling neoplastic conditions.

Deciphering non thermal plasma - human cell interaction using the proteomics approach

Summary form only given. Non thermal plasmas are promising medical tools, e.g. for skin or wound treatment. To identify and basically understand the plasma - cell interaction and to guide plasma tuning efforts a deep insight into plasma - cell interaction is necessary.

NTP-mediated changes of gene expression patterns in human cell lines

In the field of wound healing research non-thermal plasma (NTP) has attracted increasing attention over the last decades. NTP has a complex composition and consists of ions, exited atoms, electrons, ultraviolet (UV) light, visible and infrared radiation, neutral molecules, and free radicals e.g. reactive oxygen and nitrogen species (ROS/RNS)1. Next to its well-established antibacterial effects it has potential proliferation promoting properties on eukaryotic cells2. Although a number of studies have been carried out to investigate the impact of NTP on human cells, not much is known about the influences on the molecular level. In order to shed some light in the complex impact NTP has on wound healing, this study analyzed in detail the differential gene expression pattern of human cells involved in this process in response to NTP treatment. Besides the keratinocyte cell line HaCaT, two immune cells lines were studied - the CD4+ T helper cell line Jurkat and the monocyte cell line THP-1.

Influence of non-thermal plasma on human cell activities

Summary form only given. In physics, plasma is known as the fourth state of matter and describes a partially or fully ionized gas. Recently, non-thermal atmospheric pressure plasma sources gained attention as a possible tool for biomedical applications, emitting UV radiation and generating reactive oxygen and nitrogen species (ROS, RNS) [1]. It is well known that prokaryotes die during a plasma treatment whereas eukaryotes are able to survive a comparable treatment. Therefore plasma is very interesting for healing chronic wounds. The aim of this work is to analyze plasma-mediated activation of human cells of different origin (skin, connective tissue and immune system). Therefore human keratinocytes (HaCaT), fibroblasts (MRC5) and immune cells (Jurkat T-cells and THP1 monocytes) were investigated by numerous genomic and proteomic approaches, applying a modified version of the kINPen09 plasma source [2].