19:10 - 21:00
Room: Ishikawa Ongakudō Interchange Hall
Poster Session
Tumor-secreted factors induce the maturation and secretion of IL-1β via glucose-mediated synergistic modulation of NF-κB and mTOR signaling in bone marrow-derived macrophages
Yunseo Woo1, 2, Gwang-Won Jang2, Yu-Jin Jung1, 2
1Department of Biological Sciences, Kangwon National University, Chuncheon, Rep. of Korea, 200-701., Chuncheon-si, Korea, Republic of (South), 2BIT Medical Convergence Program, Kangwon National University, Chuncheon, Rep. of Korea, 200-701., Chuncheon-si, Korea, Republic of (South)

The immunological roles of IL-1β released from macrophages are important for host responses to cancer. IL-1β has been known as a double edged sword owing to their effects of inflammation and angiogenesis on tumor tissues. In general, the protein expression of IL-1β is regulated by NF-κB pathway and functional process of IL-1β is dependent on caspase-1 activation through inflammasome assembly. However, it has been recently reported that IL-1β secretion could be involved in glycolysis-mediated mTOR signaling. Although there are many potential factors for causing inflammatory responses via NF-κB signal and there are concentration gradients of glucose for the activation of mTOR pathway in tumor tissues, little is known about the signal priority between NF-κB and mTOR pathways for production and secretion of IL-1β in macrophages under tumor-microenvironment. In this study, the cellular and molecular mechanisms to produce and secret IL-1β are demonstrated in the macrophages which are incubated in the mimicked tumor-microenvironment with the gradient of glucose concentration. Tumor-conditioned media (TCM) caused IL-1β maturation through caspase-1 activation in bone marrow-derived macrophages (BMDMs). In addition, glucose in TCM particularly enhanced to activate caspase-1 and to form ASC-ASC interaction even the secretion of matured IL-1β. It was also verified that the protein expressions of NLRP3, caspase-1 and IL-1β was associated with both mTOR and NF-κB signaling pathway in BMDMs under glucose-containing TCM. However, it was observed that both NF-κB and mTOR pathways could be independently activated in BMDMs. Notably, deletion of intracellular ROS by DPI treatment attenuated elevated levels of ASC-ASC interactions in TCM-treated BMDMs. These results indicated that tumor secreted factors induced IL-1β maturation via caspase-1 activation caused by inflammasome assembly. Furthermore, these studies revealed that glucose content in TCM might be an essential factor for the activation of both NF-κB and mTOR pathways in mouse macrophages.


Reference:
Mo-P7-26
Session:
Poster Session 7 “Signal transduction and metabolic regulation”
Presenter/s:
Yunseo Woo
Presentation type:
Poster Presentation
Room:
Ishikawa Ongakudō Interchange Hall
Date:
Monday, 30 October 2017
Time:
19:10 - 21:00
Session times:
19:10 - 21:00