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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

Aldosterone-induced kidney injury is mediated by NFκB activation.

BACKGROUND: Aldosterone induces inflammation and fibrosis in the kidney, while nuclear factor κB (NFκB) plays key roles in inflammation mediated by various cytokines. Here, we determined the roles of NFκB activation in aldosterone-induced kidney injury. METHODS: We used unilaterally nephrectomized rats with or without continuous aldosterone infusion and 0.9% saline as drinking water for 3 weeks. IMD-1041, an IKKß inhibitor, and spironolactone were orally administered to inhibit NFκB and mineralocorticoid receptor, respectively. RESULTS: The aldosterone-infused rats exhibited severe kidney injury, hypertension, and increased expression of pro-inflammatory and fibrotic proteins, osteopontin, fibrinogen, collagen type I, and PAI-1. Western blotting confirmed NFκB activation by aldosterone by the increased amount of p65 in the nuclear fraction of the kidney, and oral IMD-1041 prevented the kidney injury and lessened the increase in pro-inflammatory and fibrotic proteins without significant changes in blood pressures. In addition, changes in angiotensin-converting enzyme 2 (ACE2), which has been found to act as a protective factor in various kidney injury models, were examined. Immunofluorescence studies revealed the presence of ACE2 in the brush-border membrane of the proximal convoluted tubules and markedly blunted ACE2 staining in aldosterone-infused rats. The decrease in amount of ACE2 protein was confirmed by Western blotting, and IMD-1041 also prevented the decrease in ACE2. The administration of spironolactone also abolished the effects of aldosterone. CONCLUSION: Our results suggest that aldosterone induces kidney injury via activation of NFκB and mineralocorticoid receptor, and that decreased ACE2 expression may play an important role in aldosterone-induced kidney injury.

Effects of pharmacological suppression of plasminogen activator inhibitor-1 in myocardial remodeling after ischemia reperfusion injury.

Plasminogen activator inhibitor-1 (PAI-1) contributes to cardiac ventricular remodeling because migration of inflammatory cells and attenuation of extracellular matrix degradation are caused by plasmin and matrix metalloproteinase. However, the roles of PAI-1 in myocardial ischemia reperfusion (I/R) injury and the following inflammatory response have not yet been well elucidated. To clarify the role of PAI-1 in myocardial I/R injury, we used a specific PAI-1 inhibitor (IMD-1622) in a rat model. The left anterior descending coronary artery was ligated and reperfusion was performed by loosening the suture after 30 minutes of arterial occlusion. A single administration of IMD-1622 (20 mg/kg) or vehicle was given intraperitoneally and then the rats were sacrificed on day 1 or day 14 after I/R. Blood pressure, echocardiograms, histopathology, and molecular examination were performed. The examinations revealed that PAI-1 inhibitor showed limited effects on cardiac dysfunction and ventricular remodeling after I/R. We conclude that the pharmacological inhibition of PAI-1 may not affect ventricular remodeling after myocardial I/R injury.

Antiallergic and anti-inflammatory effects of a novel I kappaB kinase beta inhibitor, IMD-0354, in a mouse model of allergic inflammation.

BACKGROUND: Nuclear factor (NF)-kappaB is a transcription factor known to regulate allergy-associated cytokine and chemokine production related to the induction of inflammation. I kappaB kinase beta (IKK beta), which is responsible for activation of the NF-kappaB pathway, may be an ideal molecular target to inhibit this process. IMD-0354 [N-(3,5-bis-trifluoromethyl-phenyl)-5-chloro-2-hydroxy-benzamide] is an attractive novel IKK beta inhibitor that prevents the production of inflammatory cytokines in various diseases, although it is not known if IMD-0354 is effective against allergic inflammation. This study aimed to elucidate the antiallergic effects of a newly synthesized IKK beta inhibitor, IMD-0354, in a mouse model of allergic inflammation. METHODS: We generated ovalbumin (OVA)-sensitized mice which were then challenged with OVA. IMD-0354 was administered intraperitoneally to therapeutic groups. Lung histopathology and the concentrations of cytokines and chemokines in bronchoalveolar lavage fluid (BALF) and supernatants of lung homogenates were determined. RESULTS: Administration of IMD-0354 ameliorated airway hyperresponsiveness and reduced the numbers of bronchial eosinophils and mucus-producing cells in OVA-sensitized mice. The total numbers of cells and eosinophils in BALF were also reduced by treatment with IMD-0354. Treatment with IMD-0354 inhibited the production of Th2 cytokines such as interleukin (IL)-5 and IL-13 and eotaxin in the airways and/or lungs of OVA-sensitized mice, but it did not affect the restoration of Th1 cytokines such as IL-12 and interferon-gamma under the same experimental conditions. IgE production was also inhibited by IMD-0354. CONCLUSION: A specific IKK beta inhibitor, IMD-0354, improved allergic airway inflammation and hyperresponsiveness in mice. IMD-0354 may have therapeutic potential for bronchial asthma.

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.

Activation of IkappaB kinase and NF-kappaB is essential for Helicobacter pylori-induced chronic gastritis in Mongolian gerbils.

The Mongolian gerbil model of Helicobacter pylori infection resembles human gastritis. In this study, we investigated the role of NF-kappaB activation in H. pylori-infected gerbils. Activated macrophages were significantly increased in H. pylori-infected gastric mucosa and were identified as being important cells with potent activation of NF-kappaB, which plays an important part in producing proinflammatory cytokines. Macrophage depletion by the administration of clodronate resulted in milder inflammation in gerbils infected with H. pylori. In macrophages, the inhibition of IkappaB kinase beta (IKKbeta), which is a critical kinase for NF-kappaB activation, resulted in lower proinflammatory cytokine expression caused by heat-killed H. pylori cells. Furthermore, treatment with IKKbeta inhibitor resulted in milder inflammation in gerbils with H. pylori gastritis. Collectively, our data suggest that H. pylori-mediated gastric inflammation critically depends on the efficient recruitment and activation of macrophages, with sufficient NF-kappaB activation.

Inhibition of IkappaB kinase beta restrains oncogenic proliferation of pancreatic cancer cells.

PURPOSE: Pancreatic cancer is characterized by an extremely poor prognosis due to the aggressive disease course and lack of effective therapeutic intervention. IkappaB kinase (IKK), a central kinase for nuclear factor-kappaB (NF-kappaB) activation, is often constitutively activated in pancreatic cancer cells, playing a crucial role in the malignant phenotype and resistance to anti-cancer agents. This study explored how specific inhibition of IKKbeta suppresses oncogenic proliferation of pancreatic cancer cells. EXPERIMENTAL DESIGN: We employed two different approaches, RNA interference-mediated depletion of IKKbeta (IKKbetai) and use of a novel molecularly designed IKKbeta inhibitor IMD-0354 to investigate the effects on the in vitro and in vivo growth and apoptotic response of pancreatic cancer cells. RESULTS: IKKbetai and IMD-0354 efficiently suppressed constitutive NF-kappaB activity and the growth of pancreatic cancer cells in monolayer and soft agar. IMD-0354 induced Annexin V expression, a typical apoptotic cell response. Notably, daily administration of IMD-0354 significantly suppressed tumor growth in NOD/SCID/gamma c(null) (NOG) mice without any deleterious side effect. CONCLUSIONS: These results identify IKKbeta as an attractive molecular target for pancreatic cancer therapy.

A new IkappaB kinase beta inhibitor prevents human breast cancer progression through negative regulation of cell cycle transition.

Constitutive nuclear factor-kappaB (NF-kappaB) activity plays a crucial role in the development and progression of lymphoma, leukemia, and some epithelial cancers. Given the contribution of NF-kappaB in carcinogenesis, a novel approach that interferes with its activity might have therapeutic potential against cancers that respond poorly to conventional treatments. Here, we have shown that a new IkappaB kinase beta inhibitor, IMD-0354, suppressed the growth of human breast cancer cells, MDA-MB-231, HMC1-8, and MCF-7, by arresting cell cycle and inducing apoptosis. In an electrophoretic mobility shift assay and a reporter assay, IMD-0354 abolished the NF-kappaB activity in MDA-MB-231 cells in a dose-dependent manner. In the cells incubated with IMD-0354, cell cycle arrested at the G0-G1 phase and apoptotic cells were increased. The expression of some cell cycle regulatory molecules and antiapoptotic molecules was suppressed in cells treated with IMD-0354. On the other hand, cyclin-dependent kinase suppressor p27Kip1 was up-regulated by the addition of IMD-0354. Daily administration of IMD-0354 inhibited tumor expansion in immunodeficient mice into which MDA-MB-231 cells were transplanted. These results indicate that NF-kappaB may contribute to cell proliferation through up-regulation of cell cycle progression; accordingly, inhibition of NF-kappaB activity might have a therapeutic ability in the treatment of human breast cancers.