2, Pusan National University, Pusan, , Korea (the Republic of)
Non-thermal atmospheric pressure plasma (NTAPP) is described as a quasi-neutral mixture of charged particles and radicals in a partially ionized gas at atmospheric pressure. Recently, many researches attempted to take advantage of the low temperature of NTAPP for biomedical applications thanks to the controllability of plasma chemistry and kinetics. Adult stem cells can differentiate into various mature cell types within tissues or organs at specific conditions. Adipose-derived stem cell (ASC) is a kind of mesenchymal stem cell, which is able to self-renew and differentiate into adipocytes, chondrocytes, osteoblasts and neurons. In this study, we exposed ASCs to NTAPP generated in a helium-based dielectric barrier discharge (DBD) device 10 times, for 50 sec each time every hour, and incubated the cells till 72 h. NTAPP exposure increased the proliferation of ASCs by 1.57-fold on an average, compared with unexposed cells. NTAPP-exposed ASCs maintained their stemness, capability to differentiate into adipocytes but did not undergo the cellular senescence. In addition, the mRNA level of well-known pluripotent genes, Oct4, Sox2 and Nanog, was increased in NTAPP-exposed ASCs compared with that of the unexposed cells. Also, signaling pathways that activate the cell proliferation such as Akt, ERK1/2, and NF-κB were activated and the proliferating cell nuclear antigen (PCNA) was highly increased at 72 h in NTAPP-exposed ASCs. Studies using the scavengers for nitric oxide (NO) and reactive oxygen species (ROS) demonstrated that NO rather than ROS is responsible for the enhanced proliferation of ASCs following NTAPP exposure. Moreover, NTAPP induced the increased proliferation of bone marrow-derived stem cells (BM-MSCs) and hematopoietic stem cells (HSCs) by 80 % and 100 %, respectively. These results suggest that NTAPP can activate the proliferation of ASCs without affecting their stem cell properties. Taken together, this study supports that NTAPP would be an efficient tool to activate the proliferation of various adult stem cells for the medical application of stem cells both in vitro and in vivo. Currently, we are investigating the whole genome expression profile of NTAPP-exposed ASCs to understand the molecular mechanism of the activation of adult stem cell proliferation by NTAPP.