A highly selective inhibitor of interleukin-1 receptor-associated kinases 1/4 (IRAK-1/4) delineates the distinct signaling roles of IRAK-1/4 and the TAK1 kinase.

Interleukin-1 receptor-associated kinase-1 (IRAK-1) and IRAK-4, as well as transforming growth factor ß-activated kinase 1 (TAK1), are protein kinases essential for transducing inflammatory signals from interleukin receptors. IRAK family proteins and TAK1 have high sequence identity within the ATP-binding pocket, limiting the development of highly selective IRAK-1/4 or TAK1 inhibitors. Beyond kinase activity, IRAKs and TAK1 act as molecular scaffolds along with other signaling proteins, complicating the interpretation of experiments involving knockin or knockout approaches. In contrast, pharmacological manipulation offers the promise of targeting catalysis-mediated signaling without grossly disrupting the cellular architecture. Recently, we reported the discovery of takinib, a potent and highly selective TAK1 inhibitor that has only marginal activity against IRAK-4. On the basis of the TAK1-takinib complex structure and the structure of IRAK-1/4, here we defined critical contact sites of the takinib scaffold within the nucleotide-binding sites of each respective kinase. Kinase activity testing of takinib analogs against IRAK-4 identified a highly potent IRAK-4 inhibitor (HS-243). In a kinome-wide screen of 468 protein kinases, HS-243 had exquisite selectivity toward both IRAK-1 (IC50 = 24 nm) and IRAK-4 (IC50 = 20 nm), with only minimal TAK1-inhibiting activity (IC50 = 0.5 µm). Using HS-243 and takinib, we evaluated the consequences of cytokine/chemokine responses after selective inhibition of IRAK-1/4 or TAK1 in response to lipopolysaccharide challenge in human rheumatoid arthritis fibroblast-like synoviocytes. Our results indicate that HS-243 specifically inhibits intracellular IRAKs without TAK1 inhibition and that these kinases have distinct, nonredundant signaling roles.

Transforming Growth Factor-ß-Activated Kinase 1 (TAK1) Alleviates Inflammatory Joint Pain in Osteoarthritis and Gouty Arthritis Preclinical Models.

Purpose: Joint pain is one of the most commonly reported pain types in the United States. In the case of patients suffering from inflammatory diseases such as osteoarthritis (OA) and gout, persistent inflammation due to long-term overexpression of several key cytokines has been linked to neuronal hypersensitivity and damage within the joints. Ultimately, a subset of patients develop chronic pain. Pharmacologic treatment of joint pain involves the use of analgesics such as acetaminophen, non-steroidal anti-inflammatory drugs (NSAIDs), opioids, antidepressants, as well as intra-articular injections of corticosteroids and hyaluronic acid. However, NSAIDs are short-acting and fail to alleviate severe pain, opioids are generally ineffective at managing chronic pain, and all therapeutic options involve increased risks of serious side effects. Methods: We explored the therapeutic and analgesic effects of transforming growth factor-ß-activated kinase 1 (TAK1) inhibition in both the monoiodoacetate (MIA) and monosodium urate (MSU) models of joint pain as an innovative strategy for alleviating chronic inflammatory pain. Mechanical allodynia (Von Frey), weight-bearing and histological changes were measured in separate groups of rats receiving either the selective TAK1 inhibitor, HS-276, gabapentin or vehicle. Results: Our data support that TAK1 inhibition effectively prevented the development of mechanical allodynia and differential weight-bearing in the MIA model. In the MSU model of gouty arthritis, treatment with HS-276 significantly reduced mechanical allodynia and knee edema in female rats, but not male rats. Histological evaluation of effected joints in both models showed that HS-276 treatment significantly reduced disease-induced degradation of the joint. Conclusion: Our results support that TAK1 is a critical signaling node in inflammatory joint diseases such as OA and gouty arthritis. Selective pharmacological inhibition significantly attenuated several aspects of the disease, including joint degeneration and mechanical pain. Thus, TAK1 is a novel therapeutic target for the treatment of painful inflammatory joint diseases. Perspective: This article reports on the therapeutic potential of TAK1 in the treatment of chronic inflammatory joint diseases such as OA and gout. Using the selective TAK1 inhibitor, HS-276, we show the therapeutic and analgesic effects of TAK1 inhibition in two preclinical murine models of inflammatory joint pain.

TAK1 inhibition leads to RIPK1-dependent apoptosis in immune-activated cancers.

Poor survival and lack of treatment response in glioblastoma (GBM) is attributed to the persistence of glioma stem cells (GSCs). To identify novel therapeutic approaches, we performed CRISPR/Cas9 knockout screens and discovered TGFß activated kinase (TAK1) as a selective survival factor in a significant fraction of GSCs. Loss of TAK1 kinase activity results in RIPK1-dependent apoptosis via Caspase-8/FADD complex activation, dependent on autocrine TNFα ligand production and constitutive TNFR signaling. We identify a transcriptional signature associated with immune activation and the mesenchymal GBM subtype to be a characteristic of cancer cells sensitive to TAK1 perturbation and employ this signature to accurately predict sensitivity to the TAK1 kinase inhibitor HS-276. In addition, exposure to pro-inflammatory cytokines IFNγ and TNFα can sensitize resistant GSCs to TAK1 inhibition. Our findings reveal dependency on TAK1 kinase activity as a novel vulnerability in immune-activated cancers, including mesenchymal GBMs that can be exploited therapeutically.

Delineation of the distinct inflammatory signaling roles of TAK1 and JAK1/3 in the CIA model of rheumatoid arthritis.

Rheumatoid arthritis (RA) is a complex autoimmune disease characterized by hyperactive immune cells within the joints, which leads to inflammation, bone degeneration, and chronic pain. For several decades, frontline immunomodulators such as the anti-tumor necrosis factor (TNF) biologics adalimumab (Humira), etanercept (Enbrel), and infliximab (Remicade) have successfully managed disease progression for many patients. However, over time, patients become refractory to these treatments requiring chronic disease to be managed with conventional and more problematic disease modifying antirheumatic drugs such as methotrexate and hydroxychloroquine, and corticosteroids. Due to the large proportion of patients who continue to fail on frontline biologic therapies, there remains an unmet need to derive novel alternative targets with improved efficacy and safety profiles to treat RA. Recent advances in the field have defined novel targets that play important roles in RA pathology, including the Janus activated kinase (JAK) and transforming growth factor beta activated kinase-1 (TAK1). Although three inhibitors of the JAK signaling pathway have been approved for the treatment of moderately to severely active RA in patients who failed on one or more anti-TNFs, at present, no FDA approved TAK1 treatments exist. Our recent discovery of a highly potent and selective, orally bioavailable TAK1 inhibitor has provided insight into the therapeutic potential of this protein kinase as a novel target for RA. Here, we show the distinct cytokine signaling of tofacitnib (Xeljanz; JAK1/3 inhibitor) compared to HS-276 (TAK1 inhibitor) in lipopolysaccharide (LPS) challenged THP-1 cells. Furthermore, in the collagen induced arthritis pre-clinical mouse model of RA, both tofacintib and HS-276 attenuated disease activity score and inflammatory cytokines in the serum. Overall, our results delineate the distinct cytokine signaling of JAK1/3 and TAK1 targeted therapies in vitro and in vivo and suggest that selective TAK1 inhibitors may provide superior therapeutic relief in RA with fewer adverse events.

Investigation of SARS-CoV-2 individual proteins reveals the in vitro and in vivo immunogenicity of membrane protein.

Evidence in SARS-CoV-2 patients have identified that viral infection is accompanied by the expression of inflammatory mediators by both immune and stromal cells within the pulmonary system. However, the immunogenicity of individual SARS-CoV-2 proteins has yet to be evaluated. The SARS-CoV-2 virus consists of 29 proteins, categorized either as nonstructural proteins (NSP's), structural proteins (SP's) or accessory proteins. Here we sought to evaluate the immunogenicity of NSP 1, 7, 8, 9, 10, 12, 14, 16 and the SP's spike protein (full length, S1, S2 and receptor binding domain subunits), nucleocapsid and membrane SARS-CoV-2 proteins against THP-1 and human peripheral blood mononuclear cells (PBMCs). Our results indicate that various SARS-CoV-2 proteins elicit a proinflammatory immune response indicated by increases in cytokines TNF, IL-6 and IL-1ß. Our results support that SARS-CoV-2 membrane protein induced a robust increase of TNF, IL-6, IL-1ß and IL-10 expression in both THP-1 and human PBMC's. Further evaluation of intranasal membrane protein challenge in male and female BALB/c mice show increases in BALF (bronchalveolar lavage fluid) proinflammatory cytokine expression, elevated cellularity, predominantly neutrophilic, and concomitant peribronchiolar and perivascular lymphomononuclear and neutrophilic inflammation. Our results suggest that individual membrane associated SARS-CoV-2 proteins induce a robust immune response that may contribute to viral induced cytokine release syndrome (CRS) in the lungs of moderate to severe COVID-19 patients. We posit that SARS-CoV-2 membrane challenges in immune-competent mice can serve as an adequate surrogate for the development of novel treatments for SARS-CoV-2 induced pulmonary inflammation, thereby avoiding expensive live virus studies under BSL-3 conditions.

Transforming Growth Factor-ß-Activated Kinase 1 (TAK1) Mediates Chronic Pain and Cytokine Production in Mouse Models of Inflammatory, Neuropathic, and Primary Pain.

The origin of chronic pain is linked to inflammation, characterized by increased levels of proinflammatory cytokines in local tissues and systemic circulation. Transforming growth factor beta-activated kinase 1 (TAK1) is a key regulator of proinflammatory cytokine signaling that has been well characterized in the context of cancer and autoimmune disorders, yet its role in chronic pain is less clear. Here, we evaluated the ability of our TAK1 small-molecule inhibitor, takinib, to attenuate pain and inflammation in preclinical models of inflammatory, neuropathic, and primary pain. Inflammatory, neuropathic, and primary pain was modeled using intraplantar complete Freund's adjuvant (CFA), chronic constriction injury (CCI), and systemic delivery of the catechol-O-methyltransferase (COMT) inhibitor OR486, respectively. Behavioral responses evoked by mechanical and thermal stimuli were evaluated in separate groups of mice receiving takinib or vehicle prior to pain induction (baseline) and over 12 days following CFA injection, 4 weeks following CCI surgery, and 6 hours following OR486 delivery. Hindpaw edema was also measured prior to and 3 days following CFA injection. Upon termination of behavioral experiments, dorsal root ganglia (DRG) were collected to measure cytokines. We also evaluated the ability of takinib to modulate nociceptor activity via in vitro calcium imaging of neurons isolated from the DRG of Gcamp3 mice. In all 3 models, TAK1 inhibition significantly reduced hypersensitivity to mechanical and thermal stimuli and expression of proinflammatory cytokines in DRG. Furthermore, TAK1 inhibition significantly reduced the activity of tumor necrosis factor (TNF)-primed/capsaicin-evoked DRG nociceptive neurons. Overall, our results support the therapeutic potential of TAK1 as a novel drug target for the treatment of chronic pain syndromes with different etiologies. PERSPECTIVE: This article reports the therapeutic potential of TAK1 inhibitors for the treatment of chronic pain. This new treatment has the potential to provide a greater therapeutic offering to physicians and patients suffering from chronic pain as well as reduce the dependency on opioid-based pain treatments.

Pharmacological inhibition of TAK1 prevents and induces regression of experimental organ fibrosis.

Multiorgan fibrosis in systemic sclerosis (SSc) accounts for substantial mortality and lacks effective therapies. Lying at the crossroad of TGF-ß and TLR signaling, TGF-ß-activated kinase 1 (TAK1) might have a pathogenic role in SSc. We therefore sought to evaluate the TAK1 signaling axis in patients with SSc and to investigate pharmacological TAK1 blockade using a potentially novel drug-like selective TAK1 inhibitor, HS-276. Inhibiting TAK1 abrogated TGF-ß1 stimulation of collagen synthesis and myofibroblasts differentiation in healthy skin fibroblasts, and it ameliorated constitutive activation of SSc skin fibroblasts. Moreover, treatment with HS-276 prevented dermal and pulmonary fibrosis and reduced the expression of profibrotic mediators in bleomycin-treated mice. Importantly, initiating HS-276 treatment even after fibrosis was already established prevented its progression in affected organs. Together, these findings implicate TAK1 in the pathogenesis of SSc and identify targeted TAK1 inhibition using a small molecule as a potential strategy for the treatment of SSc and other fibrotic diseases.

Development and Efficacy of an Orally Bioavailable Selective TAK1 Inhibitor for the Treatment of Inflammatory Arthritis.

Selective targeting of TNF in inflammatory diseases such as rheumatoid arthritis (RA) has provided great therapeutic benefit to many patients with chronic RA. Although these therapies show initially high response rates, their therapeutic benefit is limited over the lifetime of the patient due to the development of antidrug antibodies that preclude proper therapeutic benefits. As a result, patients often return to more problematic therapies such as methotrexate or hydroxychloroquine, which carry long-term side effects. Thus, there is an unmet medical need to develop alternative treatments enabling patients to regain the benefits of selectively targeting TNF functions in vivo. The protein kinase TAK1 is a critical signaling node in TNF-mediated intracellular signaling, regulating downstream NF-κß activation, leading to the transcription of inflammatory cytokines. TAK1 inhibitors have been developed but have been limited in their clinical advancement due to the lack of selectivity within the human kinome and, most importantly, lack of oral bioavailability. Using a directed medicinal chemistry approach, driven by the cocrystal structure of the TAK1 inhibitor takinib, we developed HS-276, a potent (Ki = 2.5 nM) and highly selective orally bioavailable TAK1 inhibitor. Following oral administration in normal mice, HS-276 is well tolerated (MTD >100 mg/Kg), displaying >95% bioavailability with µM plasma levels. The in vitro and in vivo efficacy of HS-276 showed significant inhibition of TNF-mediated cytokine profiles, correlating with significant attenuation of arthritic-like symptoms in the CIA mouse model of inflammatory RA. Our studies reinforce the hypothesis that TAK1 can be safely targeted pharmacologically to provide an effective alternative to frontline biologic-based RA therapeutics.

Expression of ectopic heat shock protein 90 in male and female primary afferent nociceptors regulates inflammatory pain.

ABSTRACT: Heat shock protein 90 (Hsp90) is a ubiquitously expressed integral cellular protein essential for regulating proteomic stress. Previous research has shown that Hsp90 regulates critical signaling pathways underlying chronic pain and inflammation. Recent discovery of membrane bound ectopic Hsp90 (eHsp90) on tumor cells has shown that Hsp90 induction to the plasma membrane can stabilize disease-relevant proteins. Here, we characterize eHsp90 expression in a mouse model of inflammation and demonstrate its role in nociception and pain. We found that intraplantar complete Freund adjuvant (CFA) induced robust expression of eHsp90 on the cell membranes of primary afferent nociceptors located in the L3-L5 dorsal root ganglia (DRG), bilaterally, with minimal to no expression in other tissues. Complete Freund adjuvant-induced increases in eHsp90 expression on lumbar DRG were significantly greater in females compared with males. Furthermore, exogenous Hsp90 applied to primary Pirt-GCaMP3 nociceptors induced increases in calcium responses. Responses were estrogen-dependent such that greater activity was observed in female or estrogen-primed male nociceptors compared with unprimed male nociceptors. Treatment of mice with the selective eHsp90 inhibitor HS-131 (10 nmol) significantly reversed CFA-induced mechanical pain, thermal heat pain, and hind paw edema. Notably, a higher dose (20 nmol) of HS-131 was required to achieve analgesic and anti-inflammatory effects in females. Here, we provide the first demonstration that inflammation leads to an upregulation of eHsp90 on DRG nociceptors in a sex-dependent manner and that inhibition of eHsp90 reduces nociceptor activity, pain, and inflammation. Thus, eHsp90 represents a novel therapeutic axis for the development of gender-tailored treatments for inflammatory pain.

Expression of membrane Hsp90 is a molecular signature of T cell activation.

Heat shock protein 90 (Hsp90) maintains cellular proteostasis during stress and has been under investigation as a therapeutic target in cancer for over two decades. We and others have identified a membrane expressed form of Hsp90 (mHsp90) that previously appeared to be restricted to rapidly proliferating cells exhibiting a metastatic phenotype. Here, we used HS-131, a fluor-tethered mHsp90 inhibitor, to quantify the effect of T cell activation on the expression of mHsp90 in human and mouse T cells. In cell-based assays, stimulation of human T cells induced a 20-fold increase in mHsp90 expression at the plasma membrane, suggesting trafficking of mHsp90 is regulated by TCR and inflammatory mediated signaling. Following injection of HS-131 in mouse models of human rheumatoid arthritis and inflammatory bowel disease, we detected localization of the probe at sites of active disease, consistent with immune cell invasion. Moreover, despite rapid hepatobiliary clearance, HS-131 demonstrated efficacy in reducing the mean clinical score in the CIA arthritis model. Our results suggest mHsp90 expression on T cells is a molecular marker of T cell activation and potentially a therapeutic target for chronic diseases such as rheumatoid arthritis.

TAK1: a potent tumour necrosis factor inhibitor for the treatment of inflammatory diseases.

Aberrant tumour necrosis factor (TNF) signalling is a hallmark of many inflammatory diseases including rheumatoid arthritis (RA), irritable bowel disease and lupus. Maladaptive TNF signalling can lead to hyper active downstream nuclear factor (NF)-κß signalling in turn amplifying a cell's inflammatory response and exacerbating disease. Within the TNF intracellular inflammatory signalling cascade, transforming growth factor-ß-activated kinase 1 (TAK1) has been shown to play a critical role in mediating signal transduction and downstream NF-κß activation. Owing to its role in TNF inflammatory signalling, TAK1 has become a potential therapeutic target for the treatment of inflammatory diseases such as RA. This review highlights the current development of targeting the TNF-TAK1 signalling axis as a novel therapeutic strategy for the treatment of inflammatory diseases.

TAK1 regulates the tumor microenvironment through inflammatory, angiogenetic and apoptotic signaling cascades.

Transforming growth factor beta-activated kinase 1 (TAK1) has been implicated for its role in inflammatory signaling and as an important mediator of cellular apoptosis and necroptosis in various cell types. Our recent discovery of a first-in-class, potent and selective TAK1 inhibitor, takinib, represents a novel pharmacological tool to evaluate TAK1's role in cancer. In this study we evaluated the potential therapeutic capacity of TAK1 inhibition on tumor growth and on tumor microenvironment remodeling. In a screen of 16 cancer cell lines, takinib in combination with tumor necrosis factor (TNF) was found to induce cell death (>20%) in 6 out of 16 cell lines. Furthermore, knocking out of TAK1 in MDA-MB-231 cells dramatically increased their sensitization to TNF-mediated apoptosis. In vivo xenographs of MDA-MB-231 TAK1KO tumors displayed delayed tumor growth and increased overall survival compared to TAK1WT controls. Histological and proteomic analysis of TAK1KO tumors showed altered angiogenic signaling and inflammatory signaling via immune cells. Overall, these findings suggest that the targeting of TAK1 in immune mediated cancers may be a novel therapeutic axis.

Pharmacological inhibition of TAK1, with the selective inhibitor takinib, alleviates clinical manifestation of arthritis in CIA mice.

OBJECTIVES: To examine the ability of takinib, a selective transforming growth factor beta-activated kinase 1 (TAK1) inhibitor, to reduce the severity of murine type II collagen-induced arthritis (CIA), and to affect function of synovial cells. METHODS: Following the induction of CIA, mice were treated daily with takinib (50 mg/kg) and clinical scores assessed. Thirty-six days post-CIA induction, histology was performed on various joints of treated and vehicle-treated animals. Inflammation, pannus, cartilage damage, bone resorption, and periosteal bone formation were quantified. Furthermore, pharmacokinetics of takinib were evaluated by LC-MS in various tissues. Rheumatoid arthritis fibroblast-like synoviocytes (RA-FLS) cells were cultured with 10 µM takinib and cytokine secretion analyzed by cytokine/chemokine proteome array. Cytotoxicity of takinib for RA-FLS was measured with 24 to 48 h cultures in the presence or absence of tumor necrosis factor (TNF). RESULTS: Here, we show takinib's ability to reduce the clinical score in the CIA mouse model of rheumatoid arthritis (RA) (p < 0.001). TAK1 inhibition reduced inflammation (p < 0.01), cartilage damage (p < 0.01), pannus, bone resorption, and periosteal bone formation and periosteal bone width in all joints of treated mice compared to vehicle treated. Significant reduction of inflammation (p < 0.004) and cartilage damage (p < 0.004) were observed in the knees of diseased treated animals, with moderate reduction seen in the forepaws and hind paws. Furthermore, the pharmacokinetics of takinib show rapid plasma clearance (t½ = 21 min). In stimulated RA-FLS cells, takinib reduced GROα, G-CSF, and ICAM-1 pro-inflammatory cytokine signaling. CONCLUSION: Our findings support the hypothesis that TAK1 targeted therapy represents a novel therapeutic axis to treat RA and other inflammatory diseases.

Genetic and pharmacological validation of TAK1 inhibition in macrophages as a therapeutic strategy to effectively inhibit TNF secretion.

Immune challenge of invading macrophages at sites of infection is associated with release of TNF, which triggers a local cytokine storm as part of the normal inflammatory response. Whereas this response maybe beneficial in fighting off infections, similar responses triggered in autoimmune diseases contribute significantly to the underlying damaging pathology associated with these diseases. Here we show that Takinib, a highly discriminatory inhibitor of transforming growth factor Beta- activated kinase 1 (TAK1), selectively and potently reduces TNF production in pro-inflammatory THP-1 macrophages. A complete survey of 110 cytokines, showed robust loss of proinflammatory cytokine responsiveness to lipopolysaccharide (LPS) and interferon gamma (IFNγ) challenge in response to Takinib. The mechanisms of action of Takinib was recapitulated in TAK1 KO macrophages. TAK1 KO cells showed significant loss of TNF production as well as release of IL-6 in response to LPS challenge. Furthermore, Takinib blocked the ability of exogenously added LPS to promote phosphorylation of, c-Jun, p38 protein kinases as well as downstream transcription factors regulated by nuclear factor κ-light-chain-enhancer of activated B cells (NFκB). In a mouse LPS challenge model, Takinib significantly reduced TNF serum levels. Our findings demonstrate that Takinib has utility in the treatment inflammatory disease by locally suppressing TNF production from invading macrophages.