ABSTRACT
Inosine monophosphate dehydrogenase (IMPDH) is a key enzyme that is involved in the de novo synthesis of purine nucleotides. Novel 2-aminooxazoles were synthesized and tested for inhibition of IMPDH catalytic activity. Multiple analogues based on this chemotype were found to inhibit IMPDH with low nanomolar potency. One of the analogues (compound 23) showed excellent in vivo activity in the inhibition of antibody production in mice and in the adjuvant induced arthritis model in rats.
Subject(s)
Enzyme Inhibitors/chemical synthesis , IMP Dehydrogenase/antagonists & inhibitors , Morpholines/chemical synthesis , Mycophenolic Acid/analogs & derivatives , Oxazoles/chemical synthesis , Animals , Antibody Formation/drug effects , Arthritis, Experimental/drug therapy , Enzyme Inhibitors/chemistry , Enzyme Inhibitors/pharmacology , Enzyme-Linked Immunosorbent Assay , Male , Mice , Mice, Inbred BALB C , Morpholines/chemistry , Morpholines/pharmacology , Mycophenolic Acid/pharmacology , Oxazoles/chemistry , Oxazoles/pharmacology , Rats , Rats, Inbred Lew , Structure-Activity RelationshipABSTRACT
IP-10 secretion is induced by pro-inflammatory cytokines and mediates the migration of CXCR3+ cells. Its elevation in clinical samples has been associated with multiple inflammatory diseases and its antagonism has been reported to be effective in several animal models of inflammatory disease. We generated a mouse anti-mouse IP-10 monoclonal antibody (mAb; Clone 20A9) that specifically bound murine IP-10 with high affinity and inhibited in vitro IP-10 induced BaF3/mCXCR3 cell migration with an IC(50) of approximately 4 nM. The 20A9 mAb was completely absorbed in vivo and had dose proportional pharmacokinetic exposure with a serum half life of 2.4-6 days. The 20A9 mAb inhibited IP-10 mediated T-cell recruitment to the airways, indicating that it is effective in vivo. However, administration of the 20A9 mAb had no significant effect on disease in mouse models of delayed type hypersensitivity, collagen induced arthritis, cardiac allograft transplantation tolerance, EAE or CD4+ CD45RBHi T-cell transfer-induced IBD. These data suggest that the 20A9 mAb can antagonize IP-10 mediated chemotaxis in vitro and in vivo and that this is insufficient to cause a therapeutic benefit in multiple mouse models of inflammatory disease.
Subject(s)
Antibodies, Monoclonal/pharmacology , Antibodies, Monoclonal/therapeutic use , Cell Movement/drug effects , Chemokine CXCL10/antagonists & inhibitors , Chemokine CXCL10/immunology , Animals , Antibodies, Monoclonal/pharmacokinetics , Arthritis, Experimental/pathology , Arthritis, Experimental/therapy , Bronchoalveolar Lavage Fluid/cytology , CD8-Positive T-Lymphocytes/cytology , CD8-Positive T-Lymphocytes/drug effects , Cell Movement/immunology , Disease Models, Animal , Encephalomyelitis, Autoimmune, Experimental/pathology , Encephalomyelitis, Autoimmune, Experimental/therapy , Female , Graft Rejection/prevention & control , Heart Transplantation/immunology , Inflammation/pathology , Inflammation/therapy , Inflammatory Bowel Diseases/pathology , Inflammatory Bowel Diseases/therapy , Male , Mice , Mice, Inbred BALB C , Mice, Inbred DBA , Mice, Inbred Strains , Mice, SCID , Precursor Cells, B-Lymphoid/cytology , Precursor Cells, B-Lymphoid/drug effects , Treatment OutcomeABSTRACT
We have recently identified BMS-345541 (1) as a highly selective and potent inhibitor of IKK-2 (IC50 = 0.30 microM), which however was considerably less potent against IKK-1 (IC50 = 4.0 microM). In order to further explore the SAR around the imidazoquinoxaline tricyclic structure of 1, we prepared a series of tetracyclic analogues (7, 13, and 18). The synthesis and biological activities of these potent IKK inhibitors are described.
Subject(s)
Heterocyclic Compounds, 4 or More Rings/chemical synthesis , Heterocyclic Compounds, 4 or More Rings/pharmacology , I-kappa B Kinase/antagonists & inhibitors , Benzimidazoles/chemical synthesis , Benzimidazoles/pharmacology , Cell Line , Humans , Inhibitory Concentration 50 , Quinazolines/chemical synthesis , Quinazolines/pharmacology , Quinolines/chemical synthesis , Quinolines/pharmacology , Quinoxalines/chemical synthesis , Quinoxalines/pharmacology , Structure-Activity Relationship , Substrate SpecificityABSTRACT
It has previously been shown that BMS-345541 [4(2'-aminoethyl)amino-1,8-dimethylimidazo(1,2-a)quinoxaline], a highly-selective inhibitor of IkappaB kinase (IKK), blocks both inflammation and joint destruction in murine collagen-induced arthritis. Although this agent has been shown to inhibit nuclear factor-kappaB-dependent cytokine expression in mice, we examined whether the inhibitor directly inhibits cytokine-driven metalloproteinase expression and cartilage degradation. In SW-1353 human chondrosarcoma cells, BMS-345541 inhibited interleukin-1 (IL-1)-dependent expression of matrix metalloproteinase (MMP)-1, MMP-3, and MMP-13 in a concentration-dependent manner. IL-1 treatment failed to induce and BMS-345541 did not inhibit the expression of aggrecanases ADAMTS-4 (a disintegrin and metalloproteinase domain with thrombospondin motif) and ADAMTS-5, as well as the tissue inhibitor of metalloproteinase-3. In bovine cartilage explant cultures stimulated with IL-1 to induce aggrecan and collagen degradation over 3 weeks of culture, BMS-345541 was effective in inhibiting the degradation of both aggrecan and collagen. Secreted ADAMTS-4 was not inhibited by BMS-345541 in these explants, whereas ADAMTS-5 secretion was blocked in the same concentration range that inhibited aggrecan degradation. The ability of the IKK inhibitor to block aggrecan and collagen degradation through suppression of metalloproteinase expression, coupled with its ability to block inflammatory cytokine production, shows IKK to be a promising target for the development of novel agents to treat arthritic diseases.
Subject(s)
Cartilage/metabolism , Collagen/metabolism , Extracellular Matrix Proteins/metabolism , Gene Expression Regulation, Enzymologic/drug effects , Interleukin-1/pharmacology , Lectins, C-Type/metabolism , Metalloproteases/genetics , Protein Kinase Inhibitors/pharmacology , Proteoglycans/metabolism , ADAM Proteins/genetics , ADAMTS4 Protein , ADAMTS5 Protein , Aggrecans , Animals , Cattle , Chondrocytes/metabolism , Humans , Imidazoles/pharmacology , Phosphorylation , Procollagen N-Endopeptidase/genetics , Quinoxalines/pharmacologyABSTRACT
A series of unsymmetrical polar disulfide prodrugs 2-5 of paclitaxel were designed and synthesized as reductively activated prodrugs. These compounds behaved as prodrugs in vitro on L2987 lung carcinoma cells. In vivo evaluation in mice demonstrated that the mutual prodrug 5 with captopril exhibited significant regressions and cures.
Subject(s)
Prodrugs/metabolism , Animals , Cell Division/drug effects , Disulfides , Dithiothreitol/pharmacology , Half-Life , Humans , Inhibitory Concentration 50 , Mice , Mice, Nude , Neoplasms, Experimental/drug therapy , Oxidation-Reduction , Paclitaxel , Prodrugs/chemical synthesis , Prodrugs/pharmacology , Treatment Outcome , Tumor Cells, CulturedABSTRACT
The signal-inducible phosphorylation of serines 32 and 36 of I kappa B alpha is critical in regulating the subsequent ubiquitination and proteolysis of I kappa B alpha, which then releases NF-kappa B to promote gene transcription. The multisubunit I kappa B kinase responsible for this phosphorylation contains two catalytic subunits, termed I kappa B kinase (IKK)-1 and IKK-2. BMS-345541 (4(2'-aminoethyl)amino-1,8-dimethylimidazo(1,2-a)quinoxaline) was identified as a selective inhibitor of the catalytic subunits of IKK (IKK-2 IC(50) = 0.3 microm, IKK-1 IC(50) = 4 microm). The compound failed to inhibit a panel of 15 other kinases and selectively inhibited the stimulated phosphorylation of I kappa B alpha in cells (IC(50) = 4 microm) while failing to affect c-Jun and STAT3 phosphorylation, as well as mitogen-activated protein kinase-activated protein kinase 2 activation in cells. Consistent with the role of IKK/NF-kappa B in the regulation of cytokine transcription, BMS-345541 inhibited lipopolysaccharide-stimulated tumor necrosis factor alpha, interleukin-1 beta, interleukin-8, and interleukin-6 in THP-1 cells with IC(50) values in the 1- to 5-microm range. Although a Dixon plot of the inhibition of IKK-2 by BMS-345541 showed a non-linear relationship indicating non-Michaelis-Menten kinetic binding, the use of multiple inhibition analyses indicated that BMS-345541 binds in a mutually exclusive manner with respect to a peptide inhibitor corresponding to amino acids 26-42 of I kappa B alpha with Ser-32 and Ser-36 changed to aspartates and in a non-mutually exclusive manner with respect to ADP. The opposite results were obtained when studying the binding to IKK-1. A binding model is proposed in which BMS-345541 binds to similar allosteric sites on IKK-1 and IKK-2, which then affects the active sites of the subunits differently. BMS-345541 was also shown to have excellent pharmacokinetics in mice, and peroral administration showed the compound to dose-dependently inhibit the production of serum tumor necrosis factor alpha following intraperitoneal challenge with lipopolysaccharide. Thus, the compound is effective against NF-kappa B activation in mice and represents an important tool for investigating the role of IKK in disease models.