ABSTRACT
Wnt activation by inhibiting glycogen synthase kinase 3 (GSK-3) causes bone anabolism in rodents making GSK-3 a potential therapeutic target for osteoporotic and osteolytic metastatic bone disease. To understand the wnt pathway related to human disease translation, the ability of 3 potent inhibitors of GSK-3 (AZD2858, AR79, AZ13282107) to 1) drive osteoblast differentiation and mineralisation using human adipose-derived stem cells (hADSC) in vitro; and 2) stimulate rat bone formation in vivo was investigated. Bone anabolism/resorption was determined using clinically relevant serum biomarkers as indicators of bone turnover and bone formation assessed in femurs by histopathology and pQCT/µCT imaging. GSK-3 inhibitors caused ß-catenin stabilisation in human and rat mesenchymal stem cells, stimulated hADSC commitment towards osteoblasts and osteogenic mineralisation in vitro. AZD2858 produced time-dependent changes in serum bone turnover biomarkers and increased bone mass over 28 days exposure in rats. After 7 days, AZD2858, AR79 or AZ13282107 exposure increased the bone formation biomarker P1NP, and reduced the resorption biomarker TRAcP-5b, indicating increased bone anabolism and reduced resorption in rats. This biomarker profile was differentiated from anabolic agent PTH1-34 or the anti-resorptive Alendronate-induced changes. Increased bone formation in cortical and cancellous bone as assessed by femur histopathology supported biomarker changes. 14 day AR79 treatment increased bone mineral density and trabecular thickness, and decreased trabecular number and connectivity assessed by pQCT/µCT. GSK-3 inhibition caused hADSC osteoblastogenesis and mineralisation in vitro. Increased femur bone mass associated with changes in bone turnover biomarkers confirmed in vivo bone formation and indicated uncoupling of bone formation and resorption.
Subject(s)
Bone Remodeling/drug effects , Enzyme Inhibitors/pharmacology , Glycogen Synthase Kinase 3/antagonists & inhibitors , Mesenchymal Stem Cells/drug effects , Osteoblasts/drug effects , Osteogenesis/drug effects , Animals , Biomarkers/blood , Bone Density/drug effects , Cell Differentiation/drug effects , Enzyme Inhibitors/chemistry , Female , Femur/drug effects , Femur/metabolism , Femur/pathology , Humans , Mesenchymal Stem Cells/cytology , Mesenchymal Stem Cells/enzymology , Molecular Structure , Osteoblasts/cytology , Osteoblasts/enzymology , Rats , Rats, Sprague-DawleyABSTRACT
The identification of two novel series of formyl peptide receptor 1 (FPR1) antagonists are reported, represented by methionine benzimidazole 6 and diamide 7. Both series specifically inhibited the binding of labelled fMLF to hrFPR1 and selectively antagonized FPR1 function in human neutrophils, making them useful in vitro validation tools for the target.
Subject(s)
Drug Discovery , Receptors, Formyl Peptide/antagonists & inhibitors , Receptors, Formyl Peptide/chemistry , Humans , Molecular StructureABSTRACT
A series of pyrazole inhibitors of the human FPR1 receptor have been identified from high throughput screening. The compounds demonstrate potent inhibition in human neutrophils and attractive physicochemical and in vitro DMPK profiles to be of further interest.
Subject(s)
Pyrazoles/pharmacology , Receptors, Formyl Peptide/antagonists & inhibitors , Drug Discovery , Humans , Neutrophils/drug effects , Pyrazoles/chemistry , Structure-Activity RelationshipABSTRACT
A novel series of antagonists of the human P2X7 receptor is described. Modification of substituents enabled identification of compounds selective for the rat P2X7 receptor and provides useful pharmacological tools for evaluation of the role of P2X7 in disease.
Subject(s)
Adamantane/analogs & derivatives , Adamantane/chemical synthesis , Benzamides/chemical synthesis , Interleukin-1beta/antagonists & inhibitors , Purinergic P2 Receptor Antagonists , Adamantane/pharmacology , Animals , Benzamides/pharmacology , Blood Proteins/metabolism , Crystallography, X-Ray , Humans , In Vitro Techniques , Molecular Conformation , Monocytes/metabolism , Protein Binding , Rats , Receptors, Purinergic P2X7 , Structure-Activity RelationshipABSTRACT
Atopic dermatitis (AD) is an inflammatory skin disease characterized by infiltration of skin homing lymphocytes into the dermis. Most of these lymphocytes express the chemokine receptor CCR4, and the frequency of blood CCR4(+) lymphocytes correlates with AD disease severity. Canine AD is a pruritic inflammatory condition that shows many features of the human disease, including CCR4 overexpression. Therefore, we tested a potent selective CCR4 antagonist in an allergen challenge model of canine AD, both clinically and histologically, to investigate whether this chemokine pathway plays a role in the inflammatory response. Using a four-period randomized cross-over study design, 14 beagles were challenged with allergen and clinically monitored. Biopsy samples were taken before and after allergen challenge. A clear reduction of clinical scores was observed with oral prednisolone (P < 0.0001) but not for the CCR4 inhibitor. A subset of the dogs (5/13) showed partial inhibition (30-49%) of the clinical signs with CCR4 inhibitor treatment, and this finding was supported by the results of histopathologic analysis of skin biopsy samples. This partial response is consistent with redundancy in chemokine pathways and highlights the need for therapies blocking multiple pathways. This study shows the utility of this canine model of AD for testing new therapeutic agents.
Subject(s)
Dermatitis, Atopic/drug therapy , Dermatitis, Atopic/pathology , Receptors, CCR4/administration & dosage , Receptors, CCR4/antagonists & inhibitors , Allergens/pharmacology , Animals , Area Under Curve , Biopsy, Needle , Cross-Over Studies , Disease Models, Animal , Dogs , Female , Humans , Immunohistochemistry , Male , Random Allocation , Reference Values , Treatment OutcomeABSTRACT
A Hit-to-Lead optimisation programme was carried out on the adamantane high throughput screening hit 1 resulting in the discovery of a number of potent P2X(7) antagonists.