@article{kim_kajino-sakamoto_omori_jobin_ninomiya-tsuji_2009, title={Intestinal Epithelial-Derived TAK1 Signaling Is Essential for Cytoprotection against Chemical-Induced Colitis}, volume={4}, ISSN={["1932-6203"]}, DOI={10.1371/journal.pone.0004561}, abstractNote={Background We have previously reported that intestinal epithelium-specific TAK1 deleted mice exhibit severe inflammation and mortality at postnatal day 1 due to TNF-induced epithelial cell death. Although deletion of TNF receptor 1 (TNFR1) can largely rescue those neonatal phenotypes, mice harboring double deletion of TNF receptor 1 (TNFR1) and intestinal epithelium-specific deletion of TAK1 (TNFR1KO/TAK1IEKO) still occasionally show increased inflammation. This indicates that TAK1 is important for TNF-independent regulation of intestinal integrity. Methodology/Principal Findings In this study, we investigated the TNF-independent role of TAK1 in the intestinal epithelium. Because the inflammatory conditions were sporadically developed in the double mutant TNFR1KO/TAK1IEKO mice, we hypothesize that epithelial TAK1 signaling is important for preventing stress-induced barrier dysfunction. To test this hypothesis, the TNFR1KO/TAK1IEKO mice were subjected to acute colitis by administration of dextran sulfate sodium (DSS). We found that loss of TAK1 significantly augments DSS-induced experimental colitis. DSS induced weight loss, intestinal damages and inflammatory markers in TNFR1KO/TAK1IEKO mice at higher levels compared to the TNFR1KO control mice. Apoptosis was strongly induced and epithelial cell proliferation was decreased in the TAK1-deficient intestinal epithelium upon DSS exposure. These suggest that epithelial-derived TAK1 signaling is important for cytoprotection and repair against injury. Finally, we showed that TAK1 is essential for interleukin 1- and bacterial components-induced expression of cytoprotective factors such as interleukin 6 and cycloxygenase 2. Conclusions Homeostatic cytokines and microbes-induced intestinal epithelial TAK1 signaling regulates cytoprotective factors and cell proliferation, which is pivotal for protecting the intestinal epithelium against injury.}, number={2}, journal={PLOS ONE}, author={Kim, Jae-Young and Kajino-Sakamoto, Rie and Omori, Emily and Jobin, Christian and Ninomiya-Tsuji, Jun}, year={2009}, month={Feb} }
 @article{kim_omori_matsumoto_nunez_ninomiya-tsuji_2008, title={TAK1 is a central mediator of NOD2 signaling in epidermal cells}, volume={283}, ISSN={["1083-351X"]}, DOI={10.1074/jbc.M704746200}, abstractNote={Muramyl dipeptide (MDP) is a peptidoglycan moiety derived from commensal and pathogenic bacteria, and a ligand of its intracellular sensor NOD2. Mutations in NOD2 are highly associated with Crohn disease, which is characterized by dysregulated inflammation in the intestine. However, the mechanism linking abnormality of NOD2 signaling and inflammation has yet to be elucidated. Here we show that transforming growth factor β-activated kinase 1 (TAK1) is an essential intermediate of NOD2 signaling. We found that TAK1 deletion completely abolished MDP-NOD2 signaling, activation of NF-κB and MAPKs, and subsequent induction of cytokines/chemokines in keratinocytes. NOD2 and its downstream effector RICK associated with and activated TAK1. TAK1 deficiency also abolished MDP-induced NOD2 expression. Because mice with epidermis-specific deletion of TAK1 develop severe inflammatory conditions, we propose that TAK1 and NOD2 signaling are important for maintaining normal homeostasis of the skin, and its ablation may impair the skin barrier function leading to inflammation.}, number={1}, journal={JOURNAL OF BIOLOGICAL CHEMISTRY}, author={Kim, Jae-Young and Omori, Emily and Matsumoto, Kunihiro and Nunez, Gabriel and Ninomiya-Tsuji, Jun}, year={2008}, month={Jan}, pages={137–144} }
 @article{inagaki_omori_kim_komatsu_scott_ray_yamada_matsumoto_mishina_ninomiya-tsuji_2008, title={TAK1-binding Protein 1, TAB1, Mediates Osmotic Stress-induced TAK1 Activation but Is Dispensable for TAK1-mediated Cytokine Signaling}, volume={283}, ISSN={["1083-351X"]}, DOI={10.1074/jbc.M807574200}, abstractNote={TAK1 kinase is an indispensable intermediate in several cytokine signaling pathways including tumor necrosis factor, interleukin-1, and transforming growth factor-β signaling pathways. TAK1 also participates in stress-activated intracellular signaling pathways such as osmotic stress signaling pathway. TAK1-binding protein 1 (TAB1) is constitutively associated with TAK1 through its C-terminal region. Although TAB1 is known to augment TAK1 catalytic activity when it is overexpressed, the role of TAB1 under physiological conditions has not yet been identified. In this study, we determined the role of TAB1 in TAK1 signaling by analyzing TAB1-deficient mouse embryonic fibroblasts (MEFs). Tumor necrosis factor- and interleukin-1-induced activation of TAK1 was entirely normal in Tab1-deficient MEFs and could activate both mitogen-activated protein kinases and NF-κB. In contrast, we found that osmotic stress-induced activation of TAK1 was largely impaired in Tab1-deficient MEFs. Furthermore, we showed that the C-terminal 68 amino acids of TAB1 were sufficient to mediate osmotic stress-induced TAK1 activation. Finally, we attempted to determine the mechanism by which TAB1 activates TAK1. We found that TAK1 is spontaneously activated when the concentration is increased and that it is totally dependent on TAB1. Cell shrinkage under the osmotic stress condition increases the concentration of TAB1-TAK1 and may oligomerize and activate TAK1 in a TAB1-dependent manner. These results demonstrate that TAB1 mediates TAK1 activation only in a subset of TAK1 pathways that are mediated through spontaneous oligomerization of TAB1-TAK1.}, number={48}, journal={JOURNAL OF BIOLOGICAL CHEMISTRY}, author={Inagaki, Maiko and Omori, Emily and Kim, Jae-Young and Komatsu, Yoshihiro and Scott, Greg and Ray, Manas K. and Yamada, Gen and Matsumoto, Kunihiro and Mishina, Yuji and Ninomiya-Tsuji, Jun}, year={2008}, month={Nov}, pages={33080–33086} }