Modulation of iron metabolism by new chemicals interacting with the iron regulatory system.

Despite the vital role of iron and vulnerability of iron metabolism in disease states, it remains largely unknown whether chemicals interacting with cellular proteins are responsible for perturbation of iron metabolism. We previously demonstrated that cisplatin was an inhibitor of the iron regulatory system by blocking IRP2 (iron regulatory protein 2) binding to an iron-responsive element (IRE) located in the 3'- or 5'-UTR (untranslated region) of key iron metabolism genes such as transferrin receptor 1 (TfR1) and ferritin mRNAs. To guide the development of new chemical probes to modulate the IRP-IRE regulatory system, we used an artificial intelligence (AI)-based ligand design and screened a chemical library composed of cysteine-reactive warheads.

Aberrantly activated TAK1 links neuroinflammation and neuronal loss in Alzheimer's disease mouse models.

Neuroinflammation is causally associated with Alzheimer's disease (AD) pathology. Reactive glia cells secrete various neurotoxic factors that impair neuronal homeostasis eventually leading to neuronal loss. Although the glial activation mechanism in AD has been relatively well studied, how it perturbs intraneuronal signaling, which ultimately leads to neuronal cell death, remains poorly understood.

Necroptosis mediators RIPK3 and MLKL suppress intracellular replication independently of host cell killing.

RIPK3, a key mediator of necroptosis, has been implicated in the host defense against viral infection primary in immune cells. However, gene expression analysis revealed that RIPK3 is abundantly expressed not only in immune organs but also in the gastrointestinal tract, particularly in the small intestine. We found that orally inoculated , a bacterial foodborne pathogen, efficiently spread and caused systemic infection in -deficient mice while almost no dissemination was observed in wild-type mice.

Coordinating Tissue Regeneration Through Transforming Growth Factor-β Activated Kinase 1 Inactivation and Reactivation.

Aberrant wound healing presents as inappropriate or insufficient tissue formation. Using a model of musculoskeletal injury, we demonstrate that loss of transforming growth factor-β activated kinase 1 (TAK1) signaling reduces inappropriate tissue formation (heterotopic ossification) through reduced cellular differentiation. Upon identifying increased proliferation with loss of TAK1 signaling, we considered a regenerative approach to address insufficient tissue production through coordinated inactivation of TAK1 to promote cellular proliferation, followed by reactivation to elicit differentiation and extracellular matrix production.

Compound mutations in Bmpr1a and Tak1 synergize facial deformities via increased cell death.

BMP signaling plays a critical role in craniofacial development. Augmentation of BMPR1A signaling through neural crest-specific expression of constitutively active Bmpr1a (caBmpr1a) results in craniofacial deformities in mice. To investigate whether deletion of Tak1 may rescue the craniofacial deformities caused by enhanced Smad-dependent signaling through caBMPR1A, we generated embryos to activate transcription of caBmpr1a transgene and ablate Tak1 in neural crest derivatives at the same time.

TAK1 Regulates the Nrf2 Antioxidant System Through Modulating p62/SQSTM1.

Aims: Nuclear factor erythroid 2 (NF-E2)-related factor 2 (Nrf2) is the master transcriptional regulator of antioxidant gene expression. On increased oxidative stress, an adaptor for Nrf2 degradation, Kelch-like ECH-associated protein 1 (Keap1), is directly modulated by oxidants in the cytoplasm, which results in stabilization and activation of Nrf2. Nrf2 is also constitutively active, to some extent, in the absence of exogenous oxidative stress.

TAK1 determines susceptibility to endoplasmic reticulum stress and leptin resistance in the hypothalamus.

Sustained endoplasmic reticulum (ER) stress disrupts normal cellular homeostasis and leads to the development of many types of human diseases, including metabolic disorders. TAK1 (also known as MAP3K7) is a member of the mitogen-activated protein kinase kinase kinase (MAP3K) family and is activated by a diverse set of inflammatory stimuli. Here, we demonstrate that TAK1 regulates ER stress and metabolic signaling through modulation of lipid biogenesis.

Tak1, Smad4 and Trim33 redundantly mediate TGF-β3 signaling during palate development.

Transforming growth factor-beta3 (TGF-β3) plays a critical role in palatal epithelial cells by inducing palatal epithelial fusion, failure of which results in cleft palate, one of the most common birth defects in humans. Recent studies have shown that Smad-dependent and Smad-independent pathways work redundantly to transduce TGF-β3 signaling in palatal epithelial cells. However, detailed mechanisms by which this signaling is mediated still remain to be elucidated.

Activated macrophage survival is coordinated by TAK1 binding proteins.

Macrophages play diverse roles in tissue homeostasis and immunity, and canonically activated macrophages are critically associated with acute inflammatory responses. It is known that activated macrophages undergo cell death after transient activation in some settings, and the viability of macrophages impacts on inflammatory status. Here we report that TGFβ- activated kinase (TAK1) activators, TAK1-binding protein 1 (TAB1) and TAK1-binding protein 2 (TAB2), are critical molecules in the regulation of activated macrophage survival.

TAK1 kinase switches cell fate from apoptosis to necrosis following TNF stimulation.

TNF activates three distinct intracellular signaling cascades leading to cell survival, caspase-8-mediated apoptosis, or receptor interacting protein kinase 3 (RIPK3)-dependent necrosis, also called necroptosis. Depending on the cellular context, one of these pathways is activated upon TNF challenge. When caspase-8 is activated, it drives the apoptosis cascade and blocks RIPK3-dependent necrosis.

TAK1 binding protein 2 is essential for liver protection from stressors.

The liver is the first line of defense from environmental stressors in that hepatocytes respond to and metabolize them. Hence, hepatocytes can be damaged by stressors. Protection against hepatic cell damage and cell death is important for liver function and homeostasis.

TGF-β-activated kinase 1 (Tak1) mediates agonist-induced Smad activation and linker region phosphorylation in embryonic craniofacial neural crest-derived cells.

Background: The role of Smad-independent TGF-β signaling in craniofacial development is poorly elucidated.

Results: In craniofacial mesenchymal cells, Tak1 regulates both R-Smad C-terminal and linker region phosphorylation in TGF-β signaling.

Conclusion: Tak1 plays an irreplaceable role in craniofacial ecto-mesenchyme during embryogenesis.

Kinase-independent feedback of the TAK1/TAB1 complex on BCL10 turnover and NF-κB activation.

Antigen receptors activate pathways that control cell survival, proliferation, and differentiation. Two important targets of antigen receptors, NF-κB and Jun N-terminal kinase (JNK), are activated downstream of CARMA1, a scaffolding protein that nucleates a complex including BCL10, MALT1, and other IκB kinase (IKK)-signalosome components. Somatic mutations that constitutively activate CARMA1 occur frequently in diffuse large B cell lymphoma (DLBCL) and mediate essential survival signals.

TAK1 (MAP3K7) signaling regulates hematopoietic stem cells through TNF-dependent and -independent mechanisms.

A cytokine/stress signaling kinase Tak1 (Map3k7) deficiency is known to impair hematopoietic progenitor cells. However, the role of TAK1 signaling in the stem cell function of the hematopoietic system is not yet well defined. Here we characterized hematopoietic stem cells (HSCs) harboring deletion of Tak1 and its activators, Tak1 binding proteins 1 and 2 (Tab1 and Tab2) using a competitive transplantation assay in a mouse model.

TAK1 kinase signaling regulates embryonic angiogenesis by modulating endothelial cell survival and migration.

TGF-β activated kinase 1 (TAK1) is a mediator of various cytokine signaling pathways. Germline deficiency of Tak1 causes multiple abnormalities, including dilated blood vessels at midgestation. However, the mechanisms by which TAK1 regulates vessel formation have not been elucidated.

Epithelial transforming growth factor β-activated kinase 1 (TAK1) is activated through two independent mechanisms and regulates reactive oxygen species.

Dysregulation in cellular redox systems results in accumulation of reactive oxygen species (ROS), which are causally associated with a number of disease conditions. Transforming growth factor β-activated kinase 1 (TAK1) is a signaling intermediate of innate immune signaling pathways and is critically involved in the redox regulation in vivo. Ablation of TAK1 causes accumulation of ROS, resulting in epithelial cell death and inflammation.

Inhibition of autophagy by TAB2 and TAB3.

Autophagic responses are coupled to the activation of the inhibitor of NF-κB kinase (IKK). Here, we report that the essential autophagy mediator Beclin 1 and TGFβ-activated kinase 1 (TAK1)-binding proteins 2 and 3 (TAB2 and TAB3), two upstream activators of the TAK1-IKK signalling axis, constitutively interact with each other via their coiled-coil domains (CCDs). Upon autophagy induction, TAB2 and TAB3 dissociate from Beclin 1 and bind TAK1.

Ablation of TAK1 upregulates reactive oxygen species and selectively kills tumor cells.

TAK1 kinase activates multiple transcription factors and regulates the level of reactive oxygen species (ROS). We have previously reported that ablation of TAK1 in keratinocytes causes hypersensitivity to ROS-induced cell apoptosis. It is known that some tumor cells produce ROS at higher levels compared with normal cells.

TGF-beta-activated kinase 1 signaling maintains intestinal integrity by preventing accumulation of reactive oxygen species in the intestinal epithelium.

The intestinal epithelium is constantly exposed to inducers of reactive oxygen species (ROS), such as commensal microorganisms. Levels of ROS are normally maintained at nontoxic levels, but dysregulation of ROS is involved in intestinal inflammatory diseases. In this article, we report that TGF-β-activated kinase 1 (TAK1) is a key regulator of ROS in the intestinal epithelium.

Regulation of genotoxic stress response by homeodomain-interacting protein kinase 2 through phosphorylation of cyclic AMP response element-binding protein at serine 271.

CREB (cyclic AMP response element-binding protein) is a stimulus-induced transcription factor that plays pivotal roles in cell survival and proliferation. The transactivation function of CREB is primarily regulated through Ser-133 phosphorylation by cAMP-dependent protein kinase A (PKA) and related kinases. Here we found that homeodomain-interacting protein kinase 2 (HIPK2), a DNA-damage responsive nuclear kinase, is a new CREB kinase for phosphorylation at Ser-271 but not Ser-133, and activates CREB transactivation function including brain-derived neurotrophic factor (BDNF) mRNA expression.

Transforming growth factor beta-activated kinase 1 (TAK1) kinase adaptor, TAK1-binding protein 2, plays dual roles in TAK1 signaling by recruiting both an activator and an inhibitor of TAK1 kinase in tumor necrosis factor signaling pathway.

Transforming growth factor beta-activated kinase 1 (TAK1) kinase is an indispensable signaling intermediate in tumor necrosis factor (TNF), interleukin 1, and Toll-like receptor signaling pathways. TAK1-binding protein 2 (TAB2) and its closely related protein, TAB3, are binding partners of TAK1 and have previously been identified as adaptors of TAK1 that recruit TAK1 to a TNF receptor signaling complex. TAB2 and TAB3 redundantly mediate activation of TAK1.