SECTION: Life Science
SCIENTIFIC ORGANIZATION:
Petrozavodsk State Univeristy, Petrozavodsk, Republic of Karelia, Russia
REPORT FORM:
«Poster report»
AUTHOR(S)
OF THE REPORT:
Ilyukha V.V., Bagina U.S., Kurbatova I.V., Churova M.V., Vijueva E.M., Schworer S., Poltorak A.N.
SPEAKER:
Ilyukha V.V.
REPORT TITLE:
RIP1 KINASE-DEPENDENT INFLAMMATORY RESPONSE
TALKING POINTS:

Receptor interacting protein (RIP) kinase 1 is a member of the family of serine/threonine kinases that is best characterized as mediator of stress responses to activate NF-κB, MAPK, apoptosis, and necrosis (1). (1).The kinase activity of RIP1 is required exclusively for the receptor-mediated necroptosis whereas pro-inflammatory signaling is dependent on the scaffolding function of RIP1 (2,3). Multiple recent reports have identified that, in addition to its role in executing necroptosis, RIP1 kinase activity contributes to in vivo cytokines production (4) suggesting that the molecular components of this signaling pathway warrant elucidation. In this study, we have established an in vitro system in bone marrow-derived macrophages treated with the pan-caspase inhibitor ZVAD, which led to an increase in pro-inflammatory cytokine production that was inhibited by Necrostatin-1, a specific inhibitor of the kinase activity of RIP1. The effect of RIP1 kinase was compared in two genetically diverse mouse lines such as C57BL6 and MOLF. While ZVAD treatment led to an increase in TNF, CCL3, CXCL2, and IFNβ but not IL-6 in B6 and MOLF macrophages, though the MOLF response was more robust. Studies using chemical inhibitors identified a role for p38 in the high responses of MOLF and TAK1 was important for the RIP1 kinase dependent response in both strains. Additionally, IRAK2 may be an important contributor to the hyper-production of pro-inflammatory cytokines by MOLF in a RIP1 kinase dependent fashion, however whether this occurs through inducing p38 activation is not entirely clear. Using next generation sequencing (NGS) in expression analysis of up-regulated genes, we compared RIP1-mediated expression in C57BL6 and MOLF macrophages at the genome-wide level. Overall, the data establish a model in which TLR signaling in the presence of ZVAD introduced a RIP1 kinase-dependent arm to the production of pro-inflammatory cytokines.

  1. Zhang, D., J. Lin, and J. Han. 2010. Receptor-interacting protein (RIP) kinase family. Cell Mol Immunol 7: 243–249.

  2. Meylan, E., K. Burns, K. Hofmann, V. Blancheteau, F. Martinon, M. A. Kelliher, and J. Tschopp. 2004. RIP1 is an essential mediator of Toll-like receptor 3-induced NF-kB activation. Nat Immunol 5: 503–507.

  3. Lee, T. H., J. Shank, N. Cusson, and M. A. Kelliher. 2004. The Kinase Activity of Rip1 Is Not Required for Tumor Necrosis Factor-alpha-induced IkB Kinase or p38 MAP Kinase Activation or for the Ubiquitination of Rip1 by Traf2. J. Biol. Chem. 279: 33185–33191.

  4. Christofferson, D. E., Y. Li, J. Hitomi, W. Zhou, C. Upperman, H. Zhu, S. A. Gerber, S. Gygi, and J. Yuan. 2012. A novel role for RIP1 kinase in mediating TNF-a