Design, Synthesis, and Anti-Inflammatory Evaluation of a Novel PPARδ Agonist with a 4-(1-Pyrrolidinyl)piperidine Structure.

Peroxisome proliferator-activated receptor δ (PPARδ) is considered to be a pharmaceutical target to treat metabolic diseases including atherosclerosis, but there is no PPARδ agonist available for clinical use. We have previously reported the discovery of piperidinyl/piperazinyl benzothiazole derivatives as a new series of PPARδ agonists using docking-based virtual screening methods. In the present study, we found that introduction of a pyrrolidine group into the 4-position of their central piperidine rings enhances hPPARδ activity and subtype selectivity. This led to the discovery of 21 having strong PPARδ agonist activity (EC50 = 3.6 nM) with excellent ADME properties. Furthermore, 21 significantly suppressed atherosclerosis progression by 50-60% with reduction of the serum level of MCP-1 in LDLr-KO mice.

Discovery and structure-activity relationship study of 2-piperazinyl-benzothiazole derivatives as potent and selective PPARδ agonists.

Peroxisome proliferator-activated receptor δ (PPARδ) is considered to be a target for treating metabolic syndrome, whereas there is no PPARδ agonist in clinical use. Previously, we have reported the discovery of 2-(1-piperidinyl)-1,3-benzothiazole derivatives as a new series of PPARδ agonists using docking-based virtual screening techniques. In this study, we performed the further optimization study of the lead compound 1 focusing on improvement of hydrophobic interactions in the binding site to enhance agonist efficacy for PPARδ and subtype selectivity, thereby discovering a novel PPARδ agonist 5g which exhibited high in vitro agonist activity (hPPARδ, EC50 = 4.1 nM) and sufficiently high selectivity ratio over PPARα and PPARγ. Moreover, 5g revealed a significant upregulation of high-density lipoprotein cholesterol level in vivo.

Discovery and structure-based design of a new series of potent and selective PPARδ agonists utilizing a virtual screening method.

Novel PPARδ agonists, 2-(1-piperidinyl)-1,3-benzothiazole derivatives were discovered by our proprietary docking-based virtual screening technique. Compound 1 as the initial hit was effectively modified to acquire PPARδ agonist activity, resulting in the discovery of compound 12 with high agonistic potency for PPARδ and selectivity over PPARα and PPARγ. Compound 12 also had good ADME profiles and showed in vivo efficacy as a lead.

Attenuation of experimental autoimmune uveoretinitis in mice by IKKß inhibitor IMD-0354.

Uveitis is a sight-threatening intraocular inflammatory disease that accounts for almost 10% of blindness worldwide. NF-κB signaling plays pivotal roles in inflammatory diseases. We have reported that IMD-0354, which inhibits NF-κB signaling via selective blockade of IKK-ß, suppresses inflammation in several ocular disease models. Here, we examined the therapeutic effect of IMD-0354 in an experimental autoimmune uveoretinitis (EAU) model, a well-established animal model for endogenous uveitis in humans. Systemic administration of IMD-0354 significantly suppressed the clinical and histological severity, inflammatory edema, and the translocation of NF-κB p65 into the nucleus of retinas in EAU mice. Furthermore, IMD-0354 treatment significantly inhibited the levels of several Th1/Th17-mediated pro-inflammatory cytokines in vitro. Our current data demonstrate that inhibition of IKKß with IMD-0354 ameliorates inflammatory responses in the mouse EAU model, suggesting that IMD-0354 may be a promising therapeutic agent for human endogenous uveitis.

IKKß Inhibitor IMD-0354 Attenuates Radiation Damage in Whole-body X-Irradiated Mice.

Nuclear factor-kappa B (NF-κB) transcription factor plays a critical role in regulating radiation-induced inflammatory and immune responses. Intracellular reactive oxygen species generation induces the activation of NF-κB via the inhibitor of κB (IκB) kinase (IKK) complex signaling. Previous studies have reported that the inhibition of IKK-driven NF-κB activation offers a therapeutic strategy for managing inflammatory disorders and various cancers, but it has additionally been reported that treatment targeting NF-κB also shows a radioprotective effect. IMD-0354 is an IKKß inhibitor that blocks IκBα phosphorylation in the NF-κB pathway. This compound is known to exert anti-inflammatory and antitumor effects, but its radioprotective effects are unclear. Therefore, in the present study, we examined whether or not IMD-0354 has a mitigative effect on radiation-induced damages in mice. IMD-0354 was dissolved in soybean oil and subcutaneously administered to C57BL/6J Jcl mice for 3 consecutive days after 7 Gy of whole-body X-irradiation. The survival rate on day 30 and the NF-κB p65 and IκBα in bone marrow and spleen cells based on flow cytometry were assessed. IMD-0354 administration significantly suppressed the lethality induced by whole-body X-irradiation, and the survival rate increased by 83%. The NF-κB p65 and IκBα in bone marrow and spleen cells were significantly lower in IMD-0354-treated mice than in irradiated mice, suggesting that the IKKß inhibitor IMD-0354 exerts a radiomitigative effect by suppressing the NF-κB.

A novel IkB kinase inhibitor attenuates ligature-induced periodontal disease in mice.

BACKGROUNDS AND OBJECTIVES: IMD-0354 is a novel I kappa-B kinase (IKK) inhibitor, which regulates inflammation. The purpose of this study was to examine the effect of the reagent on bone loss for ligature-induced periodontitis. MATERIAL AND METHODS: We ligated around the upper right second molars of 8-week-old C57BL/6J mice in the split-mouth model. The test mice were injected intraperitoneally with IMD-0354 before the placement of the ligature. The control mice were injected intraperitoneally with 0.5% carboxymethylcellulose (CMC) as vehicle before the placement of the ligature. To determine the optimum concentration of the reagent on ligature-induced periodontitis in the mice, we examined the effect of three types of concentration, which were 1, 5, and 10 mg/kg of IMD-0354, as a preliminary experiment. After we determined 10 mg/kg as the optimum concentration for the IMD group by micro-CT analysis, both the IMD and CMC groups (n = 15 each in total, including all the analyses) were subdivided into two small groups, respectively, for further analyses: I group (unligated side of IMD group), IL group (ligated side of IMD group), C group (unligated side of CMC group) and CL group (ligated side of CMC group). The mice in the IMD and CMC groups were treated with each reagent daily and sacrificed 8 days after the ligation. For assessment of bone resorption, we performed micro-CT and histological analyses. We also carried out real-time PCR to investigate proinflammatory and bone metabolic markers. RESULTS: There were significant differences for linear bone loss and volumetric parameter in the test (IMD) group compared to the control (CMC) group 8 days after ligation. In terms of the mRNA expression level of gingival tissue, the level of RANKL was significantly suppressed in the IMD group compared to the CMC group. IMD-0354 also tended to suppress the levels of interleukin-1 beta, tumor necrosis factor-alpha, and osteoprotegerin. For histological analysis, the relative numbers of TRAP-positive multinucleated cells decreased significantly in the IMD group compared to the CMC group. CONCLUSION: IMD-0354 regulated bone resorption by ligature-induced periodontitis, and it is suggested that the inhibition of IKK via down-regulation of NF kappa-B may provide periodontal patients with an effective approach to prevent or suppress the disease.

Plasminogen activator inhibitor-1 is an independent prognostic factor of ovarian cancer and IMD-4482, a novel plasminogen activator inhibitor-1 inhibitor, inhibits ovarian cancer peritoneal dissemination.

In the present study, the therapeutic potential of targeting plasminogen activator inhibitor-1 (PAI-1) in ovarian cancer was tested. Tissues samples from 154 cases of ovarian carcinoma were immunostained with anti-PAI-1 antibody, and the prognostic value was analyzed. Among the samples, 67% (104/154) showed strong PAI-1 expression; this was significantly associated with poor prognosis (progression-free survival: 20 vs. 31 months, P = 0.0033). In particular, among patients with stage II-IV serous adenocarcinoma, PAI-1 expression was an independent prognostic factor. The effect of a novel PAI-1 inhibitor, IMD-4482, on ovarian cancer cell lines was assessed and its therapeutic potential was examined using a xenograft mouse model of ovarian cancer. IMD-4482 inhibited in vitro cell adhesion to vitronectin in PAI-1-positive ovarian cancer cells, followed by the inhibition of extracellular signal-regulated kinase and focal adhesion kinase phosphorylation through dissociation of the PAI-urokinase receptor complex from integrin αVß3. IMD-4482 caused G0/G1 cell arrest and inhibited the proliferation of PAI-1-positive ovarian cancer cells. In the xenograft model, IMD-4482 significantly inhibited peritoneal dissemination with the reduction of PAI-1 expression and the inhibition of focal adhesion kinase phosphorylation. Collectively, the functional inhibition of PAI-1 significantly inhibited ovarian cancer progression, and targeting PAI-1 may be a potential therapeutic strategy in ovarian cancer.

The Novel IκB Kinase ß Inhibitor, IMD-0560, Has Potent Therapeutic Efficacy in Ovarian Cancer Xenograft Model Mice.

OBJECTIVE: Aberrant activation of nuclear factor-kappa ß (NF-κB) signaling has been correlated with poor outcome among patients with ovarian cancer. Although the therapeutic potential of NF-κB pathway disruption in cancers has been extensively studied, most classical NF-κB inhibitors are poorly selective, exhibit off-target effects, and have failed to be applied in clinical use. IMD-0560, N-[2,5-bis (trifluoromethyl) phenyl]-5-bromo-2-hydroxybenzamide, is a novel low-molecular-weight compound that selectively inhibits the IκB kinase complex and works as an inhibitor of NF-κB signaling. The aim of this study was to assess the therapeutic potential of IMD-0560 against ovarian cancer in vitro and in vivo. METHODS: NF-κB activity (phosphorylation) was determined in 9 ovarian cancer cell lines and the inhibitory effect of IMD-0560 on NF-κB activation was analyzed by Western blotting. Cell viability, cell cycle, vascular endothelial growth factor (VEGF) expression, and angiogenesis were assessed in vitro to evaluate the effect of IMD-0560 on ovarian cancer cells. In vivo efficacy of IMD-0560 was also investigated using an ovarian cancer xenograft mouse model. RESULTS: The NF-κB signaling pathway was constitutively activated in 8 of 9 ovarian cancer cell lines. IMD-0560 inhibited NF-κB activation and suppressed ovarian cancer cell proliferation by inducing G1 phase arrest. IMD-0560 decreased VEGF secretion from cancer cells and inhibited the tube formation of human umbilical vein endothelial cells. IMD-0560 significantly inhibited peritoneal metastasis and prolonged the survival in an ovarian cancer xenograft mice model. Immunohistochemical staining of excised tumors revealed that IMD-0560 suppressed VEGF expression, tumor angiogenesis, and cancer cell proliferation. CONCLUSIONS: IMD-0560 showed promising therapeutic efficacy against ovarian cancer xenograft mice by inducing cell cycle arrest and suppressing VEGF production from cancer cells. IMD-0560 may be a potential future option in regimens for the treatment of ovarian cancer.

Targeting Inhibitor of κB Kinase ß Prevents Inflammation-Induced Preterm Delivery by Inhibiting IL-6 Production from Amniotic Cells.

Preterm delivery (PTD) remains a serious challenge in perinatology. Intrauterine infection and/or inflammation, followed by increased inflammatory cytokines, represented by IL-6, are involved in this pathology. Our aim was to identify IL-6-producing cells in the placenta and to analyze the potential of targeting IκB kinase ß (IKKß) signaling to suppress IL-6 production for the treatment of PTD. Immunohistochemical analyses using placentas complicated with severe chorioamnionitis revealed that IL-6 is mainly expressed in human amniotic mesenchymal stromal cells (hAMSCs). Primary hAMSCs were collected, and strong IL-6 expression was confirmed. In hAMSCs, the treatment of tumor necrosis factor-α or IL-1ß drastically induced IL-6 production, followed by the phosphorylation of IKKs. A novel IKKß inhibitor, IMD-0560, almost completely inhibited IL-6 production from hAMSCs. Using an experimental lipopolysaccharide-induced PTD mouse model, the therapeutic potential of IMD-0560 was examined. IMD-0560 was delivered vaginally 4 hours before lipopolysaccharide administration. Mice in the IMD-0560 (30 mg/kg, twice a day) group had a significantly lower rate of PTD [10 of 22 (45%)] without any apparent adverse events on the mice and their pups. In uteri collected from mice, IMD-0560 inhibited not only IL-6 production but also production of related cytokines, such as keratinocyte-derived protein chemokine/CXCL1, macrophage inflammatory protein-2/CXCL2, and monocyte chemoattractant protein-1/chemokine ligand 2. Targeting IKKß signaling shows promising effects through the suppression of these cytokines and can be explored as a future option for the prevention of PTD.

IMD-4690, a novel specific inhibitor for plasminogen activator inhibitor-1, reduces allergic airway remodeling in a mouse model of chronic asthma via regulating angiogenesis and remodeling-related mediators.

Plasminogen activator inhibitor (PAI)-1 is the principal inhibitor of plasminogen activators, and is responsible for the degradation of fibrin and extracellular matrix. IMD-4690 is a newly synthesized inhibitor for PAI-1, whereas the effect on allergic airway inflammation and remodeling is still unclear. We examined the in vivo effects by using a chronic allergen exposure model of bronchial asthma in mice. The model was generated by an immune challenge for 8 weeks with house dust mite antigen, Dermatophagoides pteronyssinus (Dp). IMD-4690 was intraperitoneally administered during the challenge. Lung histopathology, hyperresponsiveness and the concentrations of mediators in lung homogenates were analyzed. The amount of active PAI-1 in the lungs was increased in mice treated with Dp. Administration with IMD-4690 reduced an active/total PAI-1 ratio. IMD-4690 also reduced the number of bronchial eosinophils in accordance with the decreased expressions of Th2 cytokines in the lung homogenates. Airway remodeling was inhibited by reducing subepithelial collagen deposition, smooth muscle hypertrophy, and angiogenesis. The effects of IMD-4690 were partly mediated by the regulation of TGF-ß, HGF and matrix metalloproteinase. These results suggest that PAI-1 plays crucial roles in airway inflammation and remodeling, and IMD-4690, a specific PAI-1 inhibitor, may have therapeutic potential for patients with refractory asthma due to airway remodeling.

IKKß Regulates VEGF Expression and Is a Potential Therapeutic Target for Ovarian Cancer as an Antiangiogenic Treatment.

The prolongation of progression-free survival (PFS) in patients with advanced ovarian cancer by antiangiogenic therapy has been shown in several clinical trials. However, although an anti-VEGF antibody (bevacizumab) is the only option currently available, its efficacy is limited and it is not cost effective for use in all patients. Therefore, the development of a novel antiangiogenic drug, especially composed of small-molecule compounds, could be a powerful armament for ovarian cancer treatment. As NF-κB signaling has the potential to regulate VEGF expression, we determined to identify whether VEGF expression is associated with NF-κB activation and to investigate the possibility of a novel IKKß inhibitor, IMD-0354 (IMMD Inc.), as an antiangiogenic drug. Tissue microarrays from 94 ovarian cancer tissues were constructed and immunohistochemical analyses performed. We revealed that IKK phosphorylation is an independent prognostic factor (PFS: 26.1 vs. 49.8 months, P = 0.011), and is positively correlated with high VEGF expression. In in vitro analyses, IMD-0354 robustly inhibited adhesive and invasive activities of ovarian cancer cells without impairing cell viabilities. IMD-0354 significantly suppressed VEGF production from cancer cells, which led to the inhibition of angiogenesis. In a xenograft model, the treatment of IMD-0354 significantly inhibited peritoneal dissemination with a marked reduction of intratumoral blood vessel formation followed by the inhibition of VEGF expression from cancer cells. IMD-0354 is a stable small-molecule drug and has already been administered safely to humans in other trials. Antiangiogenic therapy targeting IKKß is a potential future option to treat ovarian cancer.

The novel IκB kinase ß inhibitor IMD-0560 prevents bone invasion by oral squamous cell carcinoma.

Oral squamous cell carcinoma (OSCC) cells display significantly augmented nuclear factor-κB (NF-κB) activity, and inhibiting this activity suppresses malignant tumor characteristics. Thus, we evaluated the effect of IMD-0560, a novel inhibitor of IκB kinase (IKK) ß that is under assessment in a clinical trial of rheumatoid arthritis, on bone invasion by the mouse OSCC cell line SCCVII. We examined the inhibitory effects of IMD-0560 on NF-κB activity and tumor invasion using human OSCC cell lines and SCCVII cells in vitro. Using a mouse model of jaw bone invasion by SCCVII cells, we assessed the inhibitory effect of IMD-0560 on jaw bone invasion, tumor growth, and matrix degradation in vivo. IMD-0560 suppressed the nuclear translocation of NF-κB and the degradation of IκBα in OSCC cells. IMD-0560 also inhibited invasion by suppressing matrix metalloproteinase-9 (MMP-9) production in OSCC cells. IMD-0560 protected against zygoma and mandible destruction by SCCVII cells, reduced the number of osteoclasts by inhibiting receptor activator of NF-κB ligand (RANKL) expression in osteoblastic cells and SCCVII cells, increased SCCVII cell death and suppressed cell proliferation and MMP-9 production in SCCVII cells. Based on these results, IMD-0560 may represent a new therapeutic agent for bone invasion by OSCC cells.

IκB kinase-ß inhibitor IMD-0354 beneficially suppresses retinal vascular permeability in streptozotocin-induced diabetic mice.

PURPOSE: The purpose of the present study is to evaluate the effect of selective IKK-ß inhibition by IMD-0354 on inflammation, apoptosis, and angiogenesis in diabetic retinopathy (DR). METHODS: Six weeks after administration of a streptozotocin (STZ) injection, before diabetic retinopathy (DR) was evident, one group of STZ-induced diabetic mice was systemically administered with IMD-0354 (30 mg/kg) daily for another 6 weeks. Ten weeks after the STZ injection, with DR already present, another group of STZ-induced diabetic mice was administered IMD-0354 for 2 weeks. As controls, nondiabetic mice of the same age were treated with IMD-0354 for 6 weeks, and diabetic mice were treated with 10 µL of dimethyl sulfoxide (DMSO) for 6 weeks. Using these groups of mice, the following effects of IMD-0354 were analyzed: (1) inhibition of nuclear factor-κB (NF-κB) activation, (2) retinal morphology, (3) apoptotic signaling by cleaved caspase-3, (4) retinal vascular permeability, (5) angiogenesis of the retina, and (6) retinal production of VEGF. RESULTS: Systemic administration of IMD-0354 for 6 weeks to week-6 diabetic mice caused significant reduction in the loss of retinal ganglion cells and apoptotic signaling, with preservation of retinal vascular integrity and suppression of retinal VEGF expression. When inhibition of NF-κB activation treatment started after the onset of STZ-induced DR (week 10), IMD-0354 was still effective in preventing further DR progression while the vascular integrity was preserved. CONCLUSIONS: The present data indicate that NF-κB activation is the key step in the development of DR. Its suppression by IMD-0354 may present a promising therapeutic strategy for DR, especially in the early stages of the disease.

Inhibition of NF-κB activation by a novel IKK inhibitor reduces the severity of experimental autoimmune myocarditis via suppression of T-cell activation.

NF-κB, which is activated by the inhibitor of NF-κB kinase (IKK), is involved in the progression of inflammatory disease. However, the effect of IKK inhibition on the progression of myocarditis is unknown. We examined the effect of IKK inhibition on the progression of myocarditis. Lewis rats were immunized with porcine cardiac myosin to induce experimental autoimmune myocarditis (EAM). We administered the IKK inhibitor (IMD-0354; 15 mg·kg(-1)·day(-1)) or vehicle to EAM rats daily. Hearts were harvested 21 days after immunization. Although the untreated EAM group showed increased heart weight-to-body weight ratio, and severe myocardial damage, these changes were attenuated in the IKK inhibitor-treated group. Moreover, IKK inhibitor administration significantly reduced NF-κB activation and mRNA expression of IFN-γ, IL-2, and monocyte chemoattractant protein-1 in myocardium compared with vehicle administration. In vitro study showed that the IKK inhibitor treatment inhibited T-cell proliferation and Th1 cytokines production induced by myosin stimulation. The IKK inhibitor ameliorated EAM by suppressing inflammatory reactions via suppression of T-cell activation.

Pathophysiological roles of nuclear factor kappaB (NF-kB) in pulmonary arterial hypertension: effects of synthetic selective NF-kB inhibitor IMD-0354.

AIMS: Proliferation of pulmonary arterial smooth muscle cells (PASMCs) is one histological sign of pulmonary arterial hypertension (PAH). We hypothesized that a signalling cascade from fibroblast growth factor 2 (FGF2) to plasminogen activator inhibitor 1 (PAI-1) and monocyte chemotactic protein-1 (MCP-1) via nuclear transcription factor nuclear factor kappaB (NF-kB) play a critical role in progression of PAH, and tested this hypothesis both in vivo and in vitro using a synthetic selective NF-kB inhibitor, N-(3,5-Bis-trifluoromethyl-phenyl)-5-chloro-2-hydroxy-benzamide (IMD-0354). METHODS AND RESULTS: Monocrotaline (MCT) was injected into 75 Sprague-Dawley rats. Starting at day 14 after MCT injection, we administered IMD-0354 (MCT + IMD group) or vehicle (MCT group) daily. At day 32, 65% of the MCT + IMD group were alive compared with 0% of the MCT group. IMD-0354 prevented increase of right ventricular pressure, and suppressed proliferation and induced apoptosis of PASMCs. mRNA transcript levels of FGF2, PAI-1, and tissue plasminogen activator (t-PA) were lower in MCT + IMD compared with MCT. In in vitro experiments, IMD-0354 inhibited p65 translocation to the nucleus promoted by FGF2 in PASMCs. Furthermore, the time courses of extracellular signal-regulated kinase (Erk) 1/2, MCP-1, and PAI-1 stimulated with FGF2 were each markedly shortened by IMD-0354. CONCLUSIONS: We speculate that the positive-feedback loop (Erk1/2-NF-kB-MCP-1-Erk1/2) is associated with progression of PAH by causing FGF2-induced inflammation in MCT rats. IMD-0354 has potential as a new therapeutic tool for PAH.

Amelioration of endotoxin-induced uveitis treated with an IκB kinase ß inhibitor in rats.

PURPOSE: Endotoxin-induced uveitis (EIU) is an animal model for acute ocular inflammation. Several substances play major roles in the development of inflammatory changes in EIU, including tumor necrosis factor-α (TNF-α), interleukin (IL)-1ß, and IL-6. These inflammatory cytokines trigger the degradation of IκB by activating IκB kinases (IKKs). Released nuclear factor kappaB (NFκB) subsequently translocates to the nucleus, where NFκB expresses its proinflammatory function. IMD-0354, N-(3,5-Bis-trifluoromethylphenyl)-5-chloro-2-hydroxybenzamide, selectively inhibits IKKß, particularly when induced by proinflammatory cytokines, such as TNF-α and IL-1ß. In the present study, we examined whether IKKß inhibition has therapeutic effects on EIU by using IMD-0354 and its prodrug IMD-1041. METHODS: Six-week-old male Lewis rats were used. EIU was induced with subcutaneous injections of 200 µg of lipopolysaccharide (LPS) from Escherichia coli that had been diluted in 0.1 ml of phosphate-buffered saline. IMD-0354 was administered intraperitoneally at 30, 10, 3, or 0 mg/kg, suspended in 1.0 ml of 0.5% carboxymethyl cellulose sodium. The prodrug IMD-1041 (100 mg/kg) was also administered orally. The rats were euthanized 24 h after LPS injection, and EIU severity was evaluated histologically. The number of infiltrating cells and the protein, TNF-α, and monocyte chemoattractant protein-1 (MCP-1) concentrations in the aqueous humor were determined. TNF-α and MCP-1 concentrations were quantified with enzyme-linked immunosorbent assay. Eye sections were also stained with anti-NFκB and phosphorylated I-κBα antibodies. RESULTS: The number of infiltrating cells in aqueous humor was 53.6±9.8×10(5), 72.5±17.0×10(5), 127.25±32.0×10(5), and 132.0±25.0×10(5) cells/ml in rats treated with 30, 10, 3, or 0 mg/kg of IMD-0354, respectively. The total protein concentrations of aqueous humor were 92.6±3.1 mg/ml, 101.5±6.8 mg/ml, 112.6±1.9 mg/ml, and 117.33±1.8 mg/ml in rats treated with 30, 10, 3, and 0 mg/kg of IMD-0354, respectively. Infiltrating cells and protein concentrations were significantly decreased by treatment with IMD-0354 (p<0.01). IMD-0354 treatment significantly reduced the concentration of TNF-α (p<0.05) and MCP-1 (p<0.01) in aqueous humor. The number of NFκB positive nuclei was reduced when treated with IMD-0354. Furthermore, IMD-0354-treated EIU rats showed only background levels of phosphorylated I-κBα; however, it was strongly expressed in the iris-ciliary body cell cytoplasm of the IMD-0354 untreated EIU rats. Oral administration of IMD-1041 also decreased the cell number (p<0.01) and protein concentration (p<0.05) of aqueous humor in EIU. CONCLUSIONS: Acute uveitis was ameliorated by inhibition of IKKß in rats. IMD-0354 and its prodrug IMD-1041 seem to be promising candidates for treating intraocular inflammation/uveitis.

Inhibition of IκB phosphorylation prevents load-induced cardiac dysfunction in mice.

Pressure overload is known to be a cause of cardiac hypertrophy that often transits to heart failure. Although nuclear factor (NF)-κB is a key factor in the progression of cardiac hypertrophy, its pathophysiology is yet to be elucidated. Thus, we aimed to show that inhibition of NF-κB activation improves pressure overload-induced cardiac dysfunction. To assess the effect of inhibition on NF-κB activation in pressure overload cardiac hypertrophy, we used IMD-1041 in a murine thoracic aortic constriction (TAC) model. IMD-1041 inhibits the phosphorylation of IκB via inhibition of IκB kinase-ß. IMD-1041 (100 mg·kg(-1)·day(-1)) or vehicle was administered orally into mice once a day, and mice were euthanized on day 42 after TAC. TAC resulted in left ventricular wall thickening, cardiac dysfunction, and increases of heart and lung weight, whereas IMD-1041 significantly suppressed the development of cardiac hypertropy 6 wk after TAC. Histologically, developed cardiac fibrosis and cardiomyocyte hypertrophy occurred in the vehicle-treated group, whereas IMD-1041 significantly attenuated these changes. IMD-1041 suppressed the expression of p65-positive cells and nuclear translocation of p65 induced by TAC compared with vehicle. Matrix metalloproteinase-2 activity increased in the vehicle + TAC-treated group; however, it was suppressed in the IMD-1041 + TAC-treated group. IMD-1041 treatment from day 28 to day 42 after TAC significantly attenuated the decrease in the percentage of fractional shortening and cardiac fibrosis without an antihypertrophic effect. In conclusion, IMD-1041 may be useful for preventing pressure overload-induced cardiac dysfunction and the transition of cardiac hypertrophy to contraction failure via suppression of NF-κB activation.

A novel IKK inhibitor prevents progression of restenosis after arterial injury in mice.

Restenosis after percutaneous coronary intervention (PCI) is still a clinically serious problem. We examined the treatment efficacy of IMD-0354, a novel IKK inhibitor, on arteriopathy. Using C57BL/6J mice, a wire-injury model was prepared and the mice were intraperitoneally injected with IMD-0354 or vehicle twice a day. The vehicle-treated injured arteries showed significantly thickened intima (3.77 ± 0.59, n = 8), however, IMD-0354 suppressed its progression (1.62 ± 0.22, n = 10, P < 0.05) on day 28. While enhanced expression of PCNA and NF-κB was observed in the untreated injured arteries, IMD-0354 significantly suppressed their expressions. Quantitative RT-PCR revealed that the expression of several inflammatory factors was reduced in the arteries from mice which received IMD-0354 treatment compared with the control animals. Thus, this drug may effectively prevent restenosis after coronary intervention and other cardiovascular diseases.

Prediction of ligand binding affinity using a multiple-conformations-multiple-protonation scheme: application to estrogen receptor α.

A fast method that can predict the binding affinities of chemicals to a target protein with a high degree of accuracy will be very useful in drug design and regulatory science. We have been developing a scoring function for affinity prediction, which can be applied to extensive protein systems, and also trying to generate a prediction scheme that specializes in each target protein, with as high a predictive power as possible. In this study, we have constructed a prediction scheme with target-specific scores for estimating ligand-binding affinities to human estrogen receptor α (ERα), considering the major conformational change between agonist- and antagonist-bound forms and the change in protonation states of histidine at the ligand-binding site. The generated scheme calibrated with fewer training compounds (23 for the agonist-bound form, 17 for the antagonist-bound form) demonstrated good predictive power (a predictive r(2) of 0.83 for 154 validation compounds); this was also true for compounds with frameworks that were quite different from those of the training compounds. Our prediction scheme will be useful in drug development targeting ERα and in primary screening of endocrine disruptors, and provides a successful method of affinity prediction considering the major conformational changes in a protein.

An IκB kinase 2 inhibitor IMD-0354 suppresses the survival of adult T-cell leukemia cells.

Adult T-cell leukemia (ATL) is a fatal T-cell malignancy associated with human T-cell leukemia virus type I infection. The aberrant expression of nuclear factor-κB (NF-κB) is considered to contribute to the malignant phenotype and chemo-resistance of ATL cells. Because of the poor prognosis of ATL, the development of new therapeutic strategies is direly needed. In the present study, we show that an IκB kinase 2 (IKK2) inhibitor, IMD-0354, efficiently inhibits the survival of CD4(+) CD25(+) primary ATL cells and prevents the growth of or induces apoptosis of patient-derived ATL cell lines. Assays of transcription with integrated forms of reporter genes revealed that IMD-0354 suppresses NF-κB-dependent transcriptional activity. Moreover, the daily administration of IMD-0354 prevents the growth of tumors in mice inoculated with ATL cells. Our results suggest that targeting IKK2 with a small molecule inhibitor, such as IMD-0354, is an attractive strategy for the treatment of ATL.