Malt1 inactivation attenuates experimental colitis through the regulation of Th17 and Th1/17 cells.

OBJECTIVE AND DESIGN: Protease activity of MALT lymphoma-translocation protein 1 (Malt1) plays an important role in the development of colitis, but the detailed mechanism has not been fully elucidated. METHOD: Effects of Malt1 protease on the activation of T cells and the development of experimental colitis was investigated using Malt1 protease-deficient (PD) mouse. RESULTS: IL-2 production from CD4+ T cells of Malt1 PD mice was decreased compared with that of wild-type (WT) mice. Intraperitoneal injection of anti-CD3 antibody into Malt1 PD mouse induced less productions of IL-17 in the plasma, as well as the colonic gene expression of IL-17A, compared with WT mice, whereas IFN-γ production was not impaired. In naïve T-cell transfer colitis model, Malt1 PD T cells induced less disease severity than WT T cells. Then, reduction in the populations of Th17 and Th1/17 cells was observed in the mesenteric lymph nodes of the recipient mice transferred with Malt1 PD T cells, whereas those of Th1 cells were not impaired. IL-17A expression in the colon was also decreased in the mouse receiving Malt1 PD T cells. CONCLUSIONS: Inactivation of Malt1 protease activity abrogates Th17 and Th1/17 cell activation, resulting in the amelioration of experimental colitis.

Pharmacological effects of TAK-828F: an orally available RORγt inverse agonist, in mouse colitis model and human blood cells of inflammatory bowel disease.

OBJECTIVE AND DESIGN: To evaluate the potency of RORγt blockade for treatment of Inflammatory Bowel Disease (IBD), the efficacy of TAK-828F, a novel RORγt inverse agonist, in anti-TNF-α mAb non-responsive mouse colitis model and effect of TAK-828F on IL-17 production in peripheral mononuclear blood cells (PBMCs) of anti-TNF-α naive and treatment-failure patients of IBD was investigated. METHODS AND RESULTS: The colitis model showed Th17-dependent pathogenicity and response to anti-IL-12/23p40 monoclonal antibody (mAb), but no response to anti-TNF-α mAb. In the model, TAK-828F, at oral dosages of 1 and 3 mg/kg, inhibited progression of colitis and reduced the immune reaction that characterize Th17 cells. Anti-IL-17A mAb showed neither efficacy nor change in the T cell population and colonic gene expression in the model. In the normal mouse, a 4-week treatment of TAK-828F at 30 mg/kg did not severely reduce lymphocyte cell counts in peripheral and intestinal mucosa, which was observed in RORγ-/- mice. TAK-828F strongly inhibited IL-17 gene expression with IC50 values from 21.4 to 34.4 nmol/L in PBMCs from anti-TNF mAb naive and treatment-failure patients of IBD. CONCLUSIONS: These results indicate that RORγt blockade would provide an effective approach for treating refractory patients with IBD by blocking IL-23/Th17 pathway.

Pharmacological evaluation of TAK-828F, a novel orally available RORγt inverse agonist, on murine chronic experimental autoimmune encephalomyelitis model.

We investigated the potency of TAK-828F, a RORγt inverse agonist, in murine experimental autoimmune encephalomyelitis (EAE) model. TAK-828F inhibited the differentiation of Th17 and Th1/17 cells in inguinal lymph node. Increase of these cells in central nervous system (CNS) was also inhibited by TAK-828F. Prophylactic and therapeutic treatments of TAK-828F were efficacious in the model. Plasma concentration of TAK-828F was higher than that in CNS. These results indicate that TAK-828F mainly acts at peripheral and results in the reduction of Th17- and Th1/17-dependent inflammation in CNS. Blocking RORγt may be a promising strategy for treatment of multiple sclerosis.

Pharmacological Evaluation of TAK-828F, a Novel Orally Available RORγt Inverse Agonist, on Murine Colitis Model.

IL-17-producing Th17 cells and IFN-γ and IL-17 double-producing Th1/17 cells have been identified as the pathogenic cells in inflammatory bowel disease (IBD). Retinoic acid-related orphan receptor γt (RORγt) is a master regulator for the differentiation and activation of Th17 and Th1/17 cells. We discovered a novel orally available TAK-828F, a strong and selective RORγt inverse agonist. To assess the potential of RORγt blockade in the therapy for IBD, the efficacy of TAK-828F in activated T cell transfer mouse colitis model was investigated. This model was highly sensitive to the prophylactic treatment of anti-TNF-α monoclonal antibody but partially susceptible to sulfasalazine, tacrolimus, and prednisolone. Oral administration of TAK-828F, at doses of 1 and 3 mg/kg, b.i.d, strongly protected the progression of colitis. TAK-828F decreased the population of Th17 and Th1/17 cells in a dose-dependent manner in the mesenteric lymph node. Moreover, expression of mRNA that are characteristic of the Th17 signature, such as IL-17A and IL-17F in the colon, were inhibited by TAK-828F, while the expression of IL-10, an anti-inflammatory cytokine, was increased. In the therapeutic treatment, TAK-828F lessened disease severity compared to the vehicle control mice. Interestingly, gene expression of zonula occludens-1 (ZO-1) and mucin 2 (Muc2), which play an important role in barrier function of the intestinal mucosa, was recovered by TAK-828F. These results indicate that blocking RORγt has promising pharmacological profile in the colitis model. RORγt blockade may provide a novel therapeutic paradigm for treatment of IBD with unique mechanism by which improves imbalance of the immune system.

Role of Malt1 protease activity in pathogenesis of inflammatory disorders mediated by FcγR signaling.

MALT lymphoma-translocation protein 1 (Malt1) protease activity is triggered by stimulation of various immune receptors. Activation of Malt1 protease induces cleavage of negative regulators for immune responses, resulting in lymphocytes activation. Although Malt1 protease mediates the signaling process downstream of the T cell, B cell, and dectin receptors, its contribution in Fcγ receptor (FcγR) signaling has not been elucidated. In this study, we investigated the role of Malt1 protease activity in FcγR signaling using Malt1 protease-deficient (PD) mouse. In addition, role of Malt1 protease for the development of FcγR-mediated autoimmune disease was also investigated in vivo. Malt1 protease cleaves their substrates, such as RelB and cylindromatosis (CYLD). However, the Malt1 proteolytic activity was silenced in the Malt1 PD mice. Production of inflammatory cytokines via FcγR stimulation was decreased on dendritic cells prepared from Malt1 PD mice. In FcγR-dependent murine immune thrombocytopenia (ITP) model, gene expressions of the inflammatory cytokines in the spleen of Malt1 PD mice were lower than those of WT mice. Then, Malt1 PD mice protected the development of thrombocytopenia. These results clearly figured out that Malt1 protease activity plays an important role in the activation of innate immune cells via FcγR, and the development of FcγR-mediated autoimmune diseases. Therefore, Malt1 is an attractive target for the treatment of inflammatory diseases mediated by FcγR.

Pharmacological inhibitory profile of TAK-828F, a potent and selective orally available RORγt inverse agonist.

Retinoic acid-related orphan receptor γt (RORγt) is a key master regulator of the differentiation and activation of IL-17 producing CD4+ Th17, CD8+ Tc17 and IL-17/IFN-γ co-producing cells (Th1/17 cells). These cells play critical roles in the pathogenesis of autoimmune diseases such as inflammatory bowel disease and multiple sclerosis. Thus, RORγt is an attractive target for the treatment of these diseases. We discovered TAK-828F, an orally available potent and selective RORγt inverse agonist. The inhibitory effect on the activation and differentiation of Th17 cells by TAK-828F was evaluated in mouse and human primary cells. TAK-828F inhibited IL-17 production from mouse splenocytes and human peripheral blood mononuclear cells dose-dependently at concentrations of 0.01-10 µM without affecting the production of IFN-γ. Additionally, TAK-828F strongly inhibited Th17, Tc17 and Th1/17 cells' differentiation from naive T cells and memory CD4+ T cells at 100 nM without affecting Th1 cells' differentiation. In addition, TAK-828F improved Th17/Treg cells' population ratio by inhibiting Th17 cells' differentiation and up-regulating Treg cells. Furthermore, TAK-828F, at 100 nM, reduced the production of Th17-related cytokines (IL-17, IL-17F and IL-22) without affecting IFN-γ production in whole blood. These results demonstrate that TAK-828F has the potent and selective inhibitory activity against RORγt both in mouse and human cells. Additionally, oral administration of TAK-828F showed promising efficacy in naive T cell transfer mouse colitis model. TAK-828F may provide a novel therapeutic option to treat immune diseases by inhibiting Th17 and Th1/17 cells' differentiation and improving imbalance between Th17 and Treg cells.

MLN3126, an antagonist of the chemokine receptor CCR9, ameliorates inflammation in a T cell mediated mouse colitis model.

C-C chemokine receptor 9 (CCR9) is the homing receptor for C-C motif chemokine ligand 25 (CCL25), and contributes to the maintenance of mucosal immunity and pathogenesis of inflammatory bowel disease (IBD) through the recruitment of T cells into the gut mucosa. Recent reports suggest that the interaction of CCR9 and CCL25 in the large intestine correlate with disease severity of colonic IBD. MLN3126 is an orally available small molecular compound with potent and selective CCR9 antagonist activity. MLN3126 inhibited CCL25-induced calcium mobilization in human CCR9 transfected cells and CCL25-induced chemotaxis of mouse primary thymocytes in a dose-dependent manner. The potential effect of MLN3126 in an activated T cell transfer mouse colitis model was compared with that of an anti-tumor necrosis factor (TNF)-α antibody. CCL25 protein was detected in the colon of mucosal epithelial cells and CCR9+ CD4+ T cells were observed in the lamina propria of the colon of mice with colitis. Dietary administration of MLN3126 to the mice maintained sufficient concentration of the compound in the plasma and dose-dependently inhibited progression of colitis compared to the vehicle control group. Anti-TNF-α antibody, a surrogate for a standard of care for IBD treatment, was also efficacious in the colitis model. These results suggest that MLN3126 would be a promising orally available CCR9 antagonist to treat colonic IBD.

Discovery of [ cis-3-({(5 R)-5-[(7-Fluoro-1,1-dimethyl-2,3-dihydro-1 H-inden-5-yl)carbamoyl]-2-methoxy-7,8-dihydro-1,6-naphthyridin-6(5 H)-yl}carbonyl)cyclobutyl]acetic Acid (TAK-828F) as a Potent, Selective, and Orally Available Novel Retinoic Acid Receptor-Related Orphan Receptor γt Inverse Agonist.

A series of tetrahydronaphthyridine derivatives as novel RORγt inverse agonists were designed and synthesized. We reduced the lipophilicity of tetrahydroisoquinoline compound 1 by replacement of the trimethylsilyl group and SBDD-guided scaffold exchange, which successfully afforded compound 7 with a lower log  D value and tolerable in vitro activity. Consideration of LLE values in the subsequent optimization of the carboxylate tether led to the discovery of [ cis-3-({(5 R)-5-[(7-fluoro-1,1-dimethyl-2,3-dihydro-1 H-inden-5-yl)carbamoyl]-2-methoxy-7,8-dihydro-1,6-naphthyridin-6(5 H)-yl}carbonyl)cyclobutyl]acetic acid, TAK-828F (10), which showed potent RORγt inverse agonistic activity, excellent selectivity against other ROR isoforms and nuclear receptors, and a good pharmacokinetic profile. In animal studies, oral administration of compound 10 exhibited robust and dose-dependent inhibition of IL-17A cytokine expression in a mouse IL23-induced gene expression assay. Furthermore, development of clinical symptoms in a mouse experimental autoimmune encephalomyelitis model was significantly reduced. Compound 10 was selected as a clinical compound for the treatment of Th17-driven autoimmune diseases.

Discovery and pharmacological characterization of a new class of prolyl-tRNA synthetase inhibitor for anti-fibrosis therapy.

Scleroderma has clinical characteristics including skin and other tissue fibrosis, but there is an unmet need for anti-fibrotic therapy. Halofuginone (HF) is a well-known anti-fibrosis agent in preclinical and clinical studies which exerts its effect via inhibition of TGF-ß/Smad3 signaling pathway. Recently, prolyl-tRNA synthetase (PRS) was elucidated as a target protein for HF that binds to the proline binding site of the catalytic domain of PRS. Here, we characterized a new class of PRS inhibitor (T-3833261) that is carefully designed in a way that binds to the ATP site of the catalytic domain and does not disrupt binding of proline. The anti-fibrotic activity and the mechanism of action for T-3833261 on TGF-ß-induced fibrotic assay were compared with those of HF in primary human skin fibroblast. We evaluated in vivo effect of topical application of T-3833261 and HF on TGF-ß-induced fibrotic genes expression in mice. We found that T-3833261 suppressed TGF-ß-induced α-smooth muscle actin (α-SMA) and type I collagen α1 (COL1A1) expression through the Smad3 axis in a similar fashion to HF. In vivo topical application of T-3833261 reduced the increase of fibrotic genes expression such as α-Sma, Col1a1 and Col1a2 by TGF-ß intradermal injection to the ear of a mouse. We revealed that T-3833261 is more effective than HF under the conditions of high proline concentration, as reported in fibrotic tissues. These results suggest the potential of ATP competitive PRS inhibitors for the treatment of fibrotic diseases such as scleroderma.

Establishment and validation of a new semi-chronic dextran sulfate sodium-induced model of colitis in mice.

BACKGROUND: The dextran sulfate sodium (DSS)-induced model of colitis is a commonly used model of inflammatory bowel disease (IBD) in animals. However, there were few studies on the therapeutic efficacy of drugs for IBD after the onset of colitis in this model. We established a semi-chronic model of DSS-induced colitis in mice and used it to assess the therapeutic efficacy of agents for IBD. MATERIALS AND METHODS: Colitis was induced by administration of 3% DSS in drinking water to mice for 7days followed by 5days of normal drinking water. RESULTS: Ulcerative colitis (UC)-like symptoms including diarrhea, bloody stools and body-weight loss were observed from days 3 to 5, and continued until day 12 after DSS administration. Persistent colitis was associated with sustained local production of cytokines and was characterized by infiltration of inflammatory cells, crypt loss and erosion in the distal colon. These features are similar to those found in patients with UC. In this model, anti-tumor necrosis factor (TNF)-α antibody or anti-interleukin (IL)-12/23p40 antibody significantly ameliorated colitis when administered after the onset of colitis. However, treatment with FK506, prednisolone or sulfasalazine provided limited therapeutic benefit. CONCLUSION: The DSS-induced colitis established here showed similar symptomatic and histopathological features to those seen in human UC. This model may be available for predicting the clinical efficacy of candidate compounds for UC.

Synthesis and biological activities of 4-phenyl-5-pyridyl-1,3-thiazole derivatives as p38 MAP kinase inhibitors.

A novel series of 4-phenyl-5-pyridyl-1,3-thiazole analogues possessing potent in vitro inhibitory activity against p38 mitogen-activated protein kinase and the release of tumor necrosis factor-alpha (TNF-alpha) from human monocytic THP-1 cells stimulated by lipopolysaccharide has been identified. Subsequent structure-activity relationship (SAR) studies and optimization for absorption, distribution, metabolism, and elimination (ADME) profiles led to the identification of compounds 7 g and 10b as orally active lead candidates that block the in vivo production of proinflammatory cytokine (TNF-alpha). In pharmacokinetic studies, compound 10b showed good oral administration in mice and demonstrated significant in vivo anti-inflammatory activity in an anti-collagen monoclonal antibody-induced arthritis mouse model (minimum effective dose (MED)=30 mg/kg). Further elucidation of this class of compounds may provide novel anti-inflammatory agents, such as anti-rheumatoid arthritis drugs.