Molecular Profiling Reveals a Common Metabolic Signature of Tissue Fibrosis.

Fibrosis, or the accumulation of extracellular matrix, is a common feature of many chronic diseases. To interrogate core molecular pathways underlying fibrosis, we cross-examine human primary cells from various tissues treated with TGF-ß, as well as kidney and liver fibrosis models. Transcriptome analyses reveal that genes involved in fatty acid oxidation are significantly perturbed. Furthermore, mitochondrial dysfunction and acylcarnitine accumulation are found in fibrotic tissues. Substantial downregulation of the PGC1α gene is evident in both in vitro and in vivo fibrosis models, suggesting a common node of metabolic signature for tissue fibrosis. In order to identify suppressors of fibrosis, we carry out a compound library phenotypic screen and identify AMPK and PPAR as highly enriched targets. We further show that pharmacological treatment of MK-8722 (AMPK activator) and MK-4074 (ACC inhibitor) reduce fibrosis in vivo. Altogether, our work demonstrate that metabolic defect is integral to TGF-ß signaling and fibrosis.

Use of Microcomputed Tomography to Measure the Relaxin-induced Expansion of Intrapubic Ligaments in Mice.

Relaxin is a 6-kDa peptide in the insulin superfamily of hormones. In addition to its effects on reproductive and musculoskeletal ligaments, relaxin has demonstrated beneficial effects on cardiac, renal, and vascular systems in preclinical models. The mouse intrapubic ligament ex vivo bioassay is the current standard for measuring in vivo relaxin bioactivity. However, this bioassay necessitates euthanasia and dissection of large cohorts to measure the intrapubic ligament at specified time points. We hypothesized that µCT imaging could be used to reduce the number of animals necessary for the intrapubic ligament bioassay by enabling a single animal to be followed longitudinally throughout the study rather than euthanizing different cohorts at established time points. Female CD1 mice were used to compare µCT imaging with the current standard. Both protocols revealed significant differences in intrapubic ligament length, with the µCT data having greater power when corrected for baseline imaging. From these data, we concluded that using µCT to measure the intrapubic ligament in mice primed with estrogen and dosed with relaxin is a viable refinement and will allow the use of fewer animals in longitudinal studies and provide more robust data, because animals can serve as their own controls.

The Renal Outer Medullary Potassium Channel Inhibitor, MK-7145, Lowers Blood Pressure, and Manifests Features of Bartter's Syndrome Type II Phenotype.

The renal outer medullary potassium (ROMK) channel, located at the apical surface of epithelial cells in the thick ascending loop of Henle and cortical collecting duct, contributes to salt reabsorption and potassium secretion, and represents a target for the development of new mechanism of action diuretics. This idea is supported by the phenotype of antenatal Bartter's syndrome type II associated with loss-of-function mutations in the human ROMK channel, as well as, by cardiovascular studies of heterozygous carriers of channel mutations associated with type II Bartter's syndrome. Although the pharmacology of ROMK channels is still being developed, channel inhibitors have been identified and shown to cause natriuresis and diuresis, in the absence of any significant kaliuresis, on acute oral dosing to rats or dogs. Improvements in potency and selectivity have led to the discovery of MK-7145 [5,5'-((1R,1'R)-piperazine-1,4-diylbis(1-hydroxyethane-2,1-diyl))bis(4-methylisobenzofuran-1(3H)-one)], a potential clinical development candidate. In spontaneously hypertensive rats, oral dosing of MK-7145 causes dose-dependent lowering of blood pressure that is maintained during the entire treatment period, and that displays additive/synergistic effects when administered in combination with hydrochlorothiazide or candesartan, respectively. Acute or chronic oral administration of MK-7145 to normotensive dogs led to dose-dependent diuresis and natriuresis, without any significant urinary potassium losses or changes in plasma electrolyte levels. Elevations in bicarbonate and aldosterone were found after 6 days of dosing. These data indicate that pharmacological inhibition of ROMK has potential as a new mechanism for the treatment of hypertension and/or congestive heart failure. In addition, Bartter's syndrome type II features are manifested on exposure to ROMK inhibitors.

Discovery of a Potent and Selective ROMK Inhibitor with Pharmacokinetic Properties Suitable for Preclinical Evaluation.

A new subseries of ROMK inhibitors exemplified by 28 has been developed from the initial screening hit 1. The excellent selectivity for ROMK inhibition over related ion channels and pharmacokinetic properties across preclinical species support further preclinical evaluation of 28 as a new mechanism diuretic. Robust pharmacodynamic effects in both SD rats and dogs have been demonstrated.

Evaluation of selective inhibitors of 11ß-HSD1 for the treatment of hypertension.

In an effort to understand the origin of blood-pressure lowering effects observed in recent clinical trials with 11ß-HSD1 inhibitors, we examined a set of 11ß-HSD1 inhibitors in a series of relevant in vitro and in vivo assays. Select 11ß-HSD1 inhibitors reduced blood pressure in our preclinical models but most or all of the blood pressure lowering may be mediated by a 11ß-HSD1 independent pathway.

11ß-HSD1 inhibition reduces atherosclerosis in mice by altering proinflammatory gene expression in the vasculature.

11ß-Hydroxysteroid dehydrogenase type 1 (11ß-HSD1) is implicated in the etiology of metabolic syndrome. We previously showed that pharmacological inhibition of 11ß-HSD1 ameliorated multiple facets of metabolic syndrome and attenuated atherosclerosis in ApoE-/- mice. However, the molecular mechanism underlying the atheroprotective effect was not clear. In this study, we tested whether and how 11ß-HSD1 inhibition affects vascular inflammation, a major culprit for atherosclerosis and its associated complications. ApoE-/- mice were treated with an 11ß-HSD1 inhibitor for various periods of time. Plasma lipids and aortic cholesterol accumulation were quantified. Several microarray studies were carried out to examine the effect of 11ß-HSD1 inhibition on gene expression in atherosclerotic tissues. Our data suggest 11ß-HSD1 inhibition can directly modulate atherosclerotic plaques and attenuate atherosclerosis independently of lipid lowering effects. We identified immune response genes as the category of mRNA most significantly suppressed by 11ß-HSD1 inhibition. This anti-inflammatory effect was further confirmed in plaque macrophages and smooth muscle cells procured by laser capture microdissection. These findings in the vascular wall were corroborated by reduction in circulating MCP1 levels after 11ß-HSD1 inhibition. Taken together, our data suggest 11ß-HSD1 inhibition regulates proinflammatory gene expression in atherosclerotic tissues of ApoE-/- mice, and this effect may contribute to the attenuation of atherosclerosis in these animals.

Bicyclo[2.2.2]octyltriazole inhibitors of 11ß-hydoxysteroid dehydrogenase type 1. Pharmacological agents for the treatment of metabolic syndrome.

Following the discovery of a metabolic 'soft-spot' on a bicyclo[2.2.2]octyltriazole lead, an extensive effort was undertaken to block the oxidative metabolism and improve PK of this potent HSD1 lead. In this communication, SAR survey focusing on various alkyl chain replacements will be detailed. This effort culminated in the discovery of a potent ethyl sulfone inhibitor with an improved PK profile across species and improved physical properties.

Substituted phenyl triazoles as selective inhibitors of 11ß-Hydroxysteroid Dehydrogenase Type 1.

3-(Phenylcyclobutyl)-1,2,4-triazoles were identified as inhibitors of 11ß-Hydroxysteroid Dehydrogenase Type 1 (HSD1). They were shown to be active in the mouse in vivo pharmacodynamic model (PD) for HSD1 but exhibited a potent off-target activation of the Pregnane X Receptor (PXR). SAR studies and synthesis of analogs that led to the discovery of a selective HSD1 inhibitor are described in detail.

Identification and validation of genes affecting aortic lesions in mice.

Atherosclerosis represents the most significant risk factor for coronary artery disease (CAD), the leading cause of death in developed countries. To better understand the pathogenesis of atherosclerosis, we applied a likeli-hood-based model selection method to infer gene-disease causality relationships for the aortic lesion trait in a segregating mouse population demonstrating a spectrum of susceptibility to developing atherosclerotic lesions. We identified 292 genes that tested causal for aortic lesions from liver and adipose tissues of these mice, and we experimentally validated one of these candidate causal genes, complement component 3a receptor 1 (C3ar1), using a knockout mouse model. We also found that genes identified by this method overlapped with genes progressively regulated in the aortic arches of 2 mouse models of atherosclerosis during atherosclerotic lesion development. By comparing our gene set with findings from public human genome-wide association studies (GWAS) of CAD and related traits, we found that 5 genes identified by our study overlapped with published studies in humans in which they were identified as risk factors for multiple atherosclerosis-related pathologies, including myocardial infarction, serum uric acid levels, mean platelet volume, aortic root size, and heart failure. Candidate causal genes were also found to be enriched with CAD risk polymorphisms identified by the Wellcome Trust Case Control Consortium (WTCCC). Our findings therefore validate the ability of causality testing procedures to provide insights into the mechanisms underlying atherosclerosis development.

Use of a rigid endoscope to teach urethral catheterization of the female dog.

Urethral catheterization of the female dog is known to be a challenging procedure. The authors describe a catheterization technique in which they use a rigid endoscope to visualize the canine urogenital vestibule during the procedure. The technique is particularly helpful as a training tool for students who are not yet experienced with the canine anatomy. The endoscope is attached to a video camera and monitor, allowing others to observe and learn the procedure.

Bis-aryl triazoles as selective inhibitors of 11beta-hydroxysteroid dehydrogenase type 1.

3-Aryl-5-phenyl-(1,2,4)-triazoles were identified as selective inhibitors of 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1). They are active in both in vitro and an in vivo mouse pharmacodynamic (PD) model. The synthesis and structure activity relationships are presented.

4-Methyl-5-phenyl triazoles as selective inhibitors of 11beta-hydroxysteroid dehydrogenase type I.

4-Methyl-5-phenyl-(1,2,4)-triazoles were identified as selective inhibitors of 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1). They were active in vitro and in an in vivo mouse pharmacodynamic (PD) model. The synthesis and structure activity relationships are presented.

Phenylcyclobutyl triazoles as selective inhibitors of 11beta-hydroxysteroid dehydrogenase type I.

3-(Phenylcyclobutyl)-1,2,4-triazoles were identified as selective inhibitors of 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1). These were active both in vitro and in an in vivo mouse pharmacodynamic (PD) model. Fluorine substitution of the cyclobutane ring improved the pharmacokinetic profile significantly. The synthesis and structure-activity relationships are presented.

Characterization of the NOD/scid-[Tg]DR1 mouse expressing HLA-DRB1*01 transgene: a model of SCID-hu mouse for vaccine development.

OBJECTIVE: We previously showed enhanced engraftment of human T cells in the transgenic NonObese Diabetic/severe combined immunodeficient (NOD/scid)-DR1 mice, compared to NOD/scid mice. We now characterize their immunobiology, innate immunity, and intrahepatic neonatal engraftment of cord blood mononuclear cells (CBMNC), and test immune responses of these chimeric mice to an experimental cancer vaccine. METHODS: Fluorescence in situ hybridization analysis, blood biochemistry, hematology, and fluorescein-activated cell sorting analyses of cellular subsets were performed on NOD/scid-DR1 mice, in comparison to parental NOD/scid mice. Innate immunity and lifespan were examined. Histology of engrafted tissues and short-term intrahepatic engraftment of CBMNC were performed. Intracellular interferon-gamma (IFN-gamma) production was assessed in mice immunized with cancer vaccine. RESULTS: The DR1 transgene was located on chromosome 5 and no significant changes were observed in blood chemistry, peripheral blood counts, lymphoid subsets, natural killer cell and lipopolysaccharide response, and antigen presentation in the NOD/scid-DR1 mice, compared to NOD/scid mice. Interestingly, NOD/scid-DR1 mice had a significantly longer lifespan (approximately 14 months) than NOD/scid mice (approximately 8.5 months). Engraftment with human cord blood cells resulted in slight changes in the architecture/structure of spleens. No correlation was found between DR1 genotype of the donor CBMNC and extent of engraftment of human T cells. Enhanced engraftment of human cells was observed with intrahepatic injections of CBMNC in neonatal NOD/scid DR1 mice. Intracellular IFN-gamma was detected in human cells, when chimeric mice were immunized with a cancer vaccine. CONCLUSION: NOD/scid-DR1 mice were similar in most of the physiological parameters as the NOD/scid mice, with the exception of longer lifespan. Intrahepatic engraftment of neonatal mice is the preferred protocol of xenotransplantation in this model and the engrafted human cells can respond to a cancer vaccine.

Discovery of 4-heteroarylbicyclo[2.2.2]octyltriazoles as potent and selective inhibitors of 11beta-HSD1: novel therapeutic agents for the treatment of metabolic syndrome.

Replacement of the pentyl chain on our original bicyclo[2.2.2]octyltriazole leads 1 and 2 has led to the discovery that heteroaryl substituted bicyclo[2.2.2]octyltriazoles are potent and selective 11beta-hydroxysteroid dehydrogenase type I (11beta-HSD1) inhibitors with excellent pharmacokinetic profiles.

11beta-HSD1 inhibition ameliorates metabolic syndrome and prevents progression of atherosclerosis in mice.

The enzyme 11beta-hydroxysteroid dehydrogenase (HSD) type 1 converts inactive cortisone into active cortisol in cells, thereby raising the effective glucocorticoid (GC) tone above serum levels. We report that pharmacologic inhibition of 11beta-HSD1 has a therapeutic effect in mouse models of metabolic syndrome. Administration of a selective, potent 11beta-HSD1 inhibitor lowered body weight, insulin, fasting glucose, triglycerides, and cholesterol in diet-induced obese mice and lowered fasting glucose, insulin, glucagon, triglycerides, and free fatty acids, as well as improved glucose tolerance, in a mouse model of type 2 diabetes. Most importantly, inhibition of 11beta-HSD1 slowed plaque progression in a murine model of atherosclerosis, the key clinical sequela of metabolic syndrome. Mice with a targeted deletion of apolipoprotein E exhibited 84% less accumulation of aortic total cholesterol, as well as lower serum cholesterol and triglycerides, when treated with an 11beta-HSD1 inhibitor. These data provide the first evidence that pharmacologic inhibition of intracellular GC activation can effectively treat atherosclerosis, the key clinical consequence of metabolic syndrome, in addition to its salutary effect on multiple aspects of the metabolic syndrome itself.

Potent Kv1.3 inhibitors from correolide-modification of the C18 position.

Kv1.3, the voltage-gated potassium channel in human T cells, represents a new target for treating immunosuppression and autoimmune diseases. Correolide (1), a pentacyclic natural product, is a potent and selective Kv1.3 channel blocker. Simplification of correolide via removal of its E-ring generates enone 4, whose modification produced a new series of tetracyclic Kv1.3 blockers. The structure-activity relationship for this class of compounds in two functional assays, Rb_Kv and human T cell proliferation, is presented herein. The most potent analog 43 is 15-fold more potent than correolide as inhibitor of human T cell proliferation.

Intra-thymic/splenic engraftment of human T cells in HLA-DR1 transgenic NOD/scid mice.

A HLA-DR1 transgenic mouse (NOD/scid-DR1) was derived by breeding the existing B10.M/J-[Tg]DR1 mouse with the NOD/scid mouse. The intention was to enhance engraftment of human T cells by providing human class II elements in the tissues. Thymus and spleen fragments from adult NOD/scid-DR1 mice were transplanted under the syngeneic kidney capsules, followed by injection of human cord blood mononuclear cells (CBMNC) into transplanted tissues. FACS analyses showed that human T and B cells were consistently detected in the peripheral blood and spleen, of the chimeric mice. An average of 20% of human cells was found in the spleen and the engrafted thymus/spleen tissues. Furthermore, human cells from these tissues could proliferate with anti-human CD3 antibody and these mice could generate humoral and cellular responses to allogeneic human cells. Cytokines, such as IL-10, GMCSF, IFN-gamma, and TNF-alpha were also detected in the supernatants of the cultured human cells from the chimeric mice, when they were stimulated with allogeneic cells. Therefore, a novel mouse model with functional circulating human T and B cells was established that would facilitate the exploration of vaccine, the disease processes of autoimmunity, HIV infection, and human cancer.

Immunosuppressive effects of a Kv1.3 inhibitor.

The voltage gated potassium channel (Kv1.3) has been shown to play a role in immune responsiveness. Blockade of the channel led to diminution of T cell activation and delayed type hypersensitivity. Previous in vitro studies of the blockade were focused on T cell activation and proliferation. In this study we examined other T and monocytic cell mediated events to glean the extent of the immunosuppressive effects of a Kv1.3 specific inhibitor, Margatoxin (MgTX). We found that MgTX inhibited the intracellular production of Th-1 as well as Th-2 cytokines. MgTX can also inhibit IL-2 production and proliferation of T cells upon stimulation with anti-CD3 and VCAM-1. Furthermore, a redirected cytolytic activity was also inhibited by MgTX. However, MgTX did not inhibit generation of CTL to EBV transformed lymphoma cells or antibody-dependent cellular cytolysis mediated by monocytes. It appears that a Kv1.3 blockade does not affect all immune responses, particularly those of innate immunity.

N-isonicotinoyl-(L)-4-aminophenylalanine derivatives as tight binding VLA-4 antagonists.

A series of isonicotinoyl-(L)-aminophenylalanine derivatives was prepared and evaluated as VLA-4 antagonists. These compounds exhibit subnanomolar binding affinity to VLA-4 and significant off-rates. The interplay between off-rate, protein binding and pharmacokinetics is discussed.