Risk of thromboembolic events in patients with prolactinomas compared with patients with nonfunctional pituitary adenomas.

Prolactin has been proposed as a potent coactivator of platelet aggregation, possibly contributing to thromboembolic events. The objective of the study was to evaluate the relationship between prolactinoma and deep vein thrombosis (DVT), pulmonary embolism (PE), and cerebrovascular accident (CVA). Subjects were identified from a prospectively maintained pituitary database at the Cleveland Clinic. We retrospectively reviewed the charts of 544 subjects: 347 patients with prolactinomas (prolactinoma group) and 197 patients with nonfunctional pituitary adenomas (control group). Main outcome measures were DVT, PE and CVA. We found that 19 (5.5%) patients in the prolactinoma group and five (2.5%) patients in the control group had documented DVT, PE, or CVA, but this difference was not significant (p = 0.109). However, the mean initial prolactin level was higher at the time of diagnosis among prolactinoma patients than among controls (815.23 ng/ml vs. 15.90 ng/ml; p < 0.001). Among prolactinoma patients, 15 (5.5%) of 275 patients who underwent medical treatment (with cabergoline, bromocriptine, pergolide and/or other drug) and 4 (5.6%) of 72 patients who underwent transsphenoidal surgery had documented DVT, PE, or CVA, which suggests that dopaminergic therapy did not influence the risk of thromboembolic events. Hyperprolactinemia per se does not appear to predispose to a hypercoagulable state.

EGFR regulation of epidermal barrier function.

Keratinocyte terminal differentiation is the process that ultimately forms the epidermal barrier that is essential for mammalian survival. This process is controlled, in part, by signal transduction and gene expression mechanisms, and the epidermal growth factor receptor (EGFR) is known to be an important regulator of multiple epidermal functions. Using microarray analysis of a confluent cell density-induced model of keratinocyte differentiation, we identified 2,676 genes that are regulated by epidermal growth factor (EGF), a ligand of the EGFR. We further discovered, and separately confirmed by functional assays, that EGFR activation abrogates all of the known essential processes of keratinocyte differentiation by 1) decreasing the expression of lipid matrix biosynthetic enzymes, 2) regulating numerous genes forming the cornified envelope, and 3) suppressing the expression of tight junction proteins. In organotypic cultures of skin, EGF acted to impair epidermal barrier integrity, as shown by increased transepidermal water loss. As defective epidermal differentiation and disruption of barrier function are primary features of many human skin diseases, we used bioinformatic analyses to identify genes that are known to be associated with skin diseases. Compared with non-EGF-regulated genes, EGF-regulated genes were significantly enriched for skin disease genes. These results provide a systems-level understanding of the actions of EGFR signaling to inhibit keratinocyte differentiation, providing new insight into the role of EGFR imbalance in skin pathogenesis.

Discovery of an Oxycyclohexyl Acid Lysophosphatidic Acid Receptor 1 (LPA1) Antagonist BMS-986278 for the Treatment of Pulmonary Fibrotic Diseases.

The oxycyclohexyl acid BMS-986278 (33) is a potent lysophosphatidic acid receptor 1 (LPA1) antagonist, with a human LPA1 Kb of 6.9 nM. The structure-activity relationship (SAR) studies starting from the LPA1 antagonist clinical compound BMS-986020 (1), which culminated in the discovery of 33, are discussed. The detailed in vitro and in vivo preclinical pharmacology profiles of 33, as well as its pharmacokinetics/metabolism profile, are described. On the basis of its in vivo efficacy in rodent chronic lung fibrosis models and excellent overall ADME (absorption, distribution, metabolism, excretion) properties in multiple preclinical species, 33 was advanced into clinical trials, including an ongoing Phase 2 clinical trial in patients with lung fibrosis (NCT04308681).

Is GH nadir during OGTT a reliable test for diagnosis of acromegaly in patients with abnormal glucose metabolism?

PURPOSE: The growth hormone (GH) nadir during oral glucose tolerance test (OGTT) is the gold standard diagnostic test for acromegaly. The utility of OGTT-GH suppression test in patients with abnormal glucose metabolism (AGM) has not been well established. In this study, we compared the GH nadir during OGTT in patients evaluated for acromegaly in the presence and absence of AGM. METHODS: This is a retrospective cohort study of patients with acromegaly (G1, n = 40) and a group in whom acromegaly was not confirmed (G2, n = 53) who had OGTT-GH suppression test during 2000-2012, using a monoclonal GH immunoenzymatic assay. The patients were categorized as having normal glucose metabolism (NGM) or AGM. GH nadir during OGTT in each group were compared. RESULTS: In G1 and G2, 17 and 19 patients had AGM, respectively. Among 17 patients with diabetes, median HbA1C was 7% (range 5.7-9.6%). All except one patient had HbA1C< 8%. There was no difference in the GH nadir in patients with or without AGM within G1 (p = 0.15) and G2 (p = 0.43). All G1 patients with AGM had GH nadir > 0.4 µg/L. Four G1 patients with NGM had GH nadir<0.4 µg/L. All G2 patients had GH nadir < 0.4 µg/L, except one with NGM and GH nadir of 0.4 µg/L. CONCLUSION: Using highly sensitive GH assay, a GH nadir ≥ 0.4 µg/L during the OGTT-GH suppression test may be used for diagnosis of acromegaly in patients with AGM in the absence of poorly controlled diabetes.

Novel peroxisome proliferator-activated receptor alpha agonists lower low-density lipoprotein and triglycerides, raise high-density lipoprotein, and synergistically increase cholesterol excretion with a liver X receptor agonist.

The first generation peroxisome proliferator-activated receptor (PPAR) alpha agonist gemfibrozil reduces the risk of major cardiovascular events; therefore, more potent PPARalpha agonists for the treatment of cardiovascular diseases have been actively sought. We describe two novel, potent oxybenzylglycine PPARalpha-selective agonists, BMS-687453 [N-[[3-[[2-(4-chlorophenyl)-5-methyl-4-oxazolyl]methoxy]phenyl]methyl]-N-(methoxycarbonyl)-glycine] and BMS-711939 N-[[5-[[2-(4-chlorophenyl)-5-methyl-4-oxazolyl]methoxy]-2-fluorophenyl]methyl]-N-(methoxycarbonyl)-glycine], that robustly increase apolipoprotein (Apo) A1 and high-density lipoprotein cholesterol in human ApoA1 transgenic mice and lower low-density lipoprotein-cholesterol and triglycerides in fat-fed hamsters. These compounds have much lower potency against mouse PPARalpha than human PPARalpha; therefore, they were tested in PPARalpha-humanized mice that do not express murine PPARalpha but express human PPARalpha selectively in the liver. We developed hepatic gene induction as a novel biomarker for efficacy and demonstrate hepatic gene induction at very low doses of these compounds. BMS-711939 induces fecal cholesterol excretion, which is further increased upon cotreatment with a liver X receptor (LXR) agonist. It is surprising that this synergistic increase upon coadministration is also observed in mice that express PPARalpha in the liver only. BMS-711939 also prevented the LXR agonist-induced elevation of serum triglycerides. Such PPARalpha agonists could be attractive candidates to explore for the treatment of cardiovascular diseases, especially in combination with a suitable LXR agonist.

(3R,5S,E)-7-(4-(4-fluorophenyl)-6-isopropyl-2-(methyl(1-methyl-1h-1,2,4-triazol-5-yl)amino)pyrimidin-5-yl)-3,5-dihydroxyhept-6-enoic acid (BMS-644950): a rationally designed orally efficacious 3-hydroxy-3-methylglutaryl coenzyme-a reductase inhibitor with reduced myotoxicity potential.

3-hydroxy-3-methylglutaryl coenzyme-A reductase (HMGR) inhibitors, more commonly known as statins, represent the gold standard in treating hypercholesterolemia. Although statins are regarded as generally safe, they are known to cause myopathy and, in rare cases, rhabdomyolysis. Statin-dependent effects on plasma lipids are mediated through the inhibition of HMGR in the hepatocyte, whereas evidence suggests that myotoxicity is due to inhibition of HMGR within the myocyte. Thus, an inhibitor with increased selectivity for hepatocytes could potentially result in an improved therapeutic window. Implementation of a strategy that focused on in vitro potency, compound polarity, cell selectivity, and oral absorption, followed by extensive efficacy and safety modeling in guinea pig and rat, resulted in the identification of compound 1b (BMS-644950). Using this discovery pathway, we compared 1b to other marketed statins to demonstrate its outstanding efficacy and safety profile. With the potential to generate an excellent therapeutic window, 1b was advanced into clinical development.

A synthesis of N-bridged 5,6-bicylic pyridines via a mild cyclodehydration using the burgess reagent and discovery of a novel carbamylsulfonylation reaction.

Cyclodehydration using the Burgess reagent provided a novel approach toward the synthesis of N-bridged 5,6-bicylic pyridines including pyrolo-, imidazo-, and triazolopyridines under mild and neutral conditions. The methodology tolerates acid-sensitive functional groups. A novel addition product was observed between the resulting pyrrolo- or imidazopyridine and an additional equivalent of the Burgess reagent, producing the corresponding sulfonylcarbamate adduct.

Discovery of Clinical Candidate BMS-823778 as an Inhibitor of Human 11ß-Hydroxysteroid Dehydrogenase Type 1 (11ß-HSD-1).

BMS-823778 (2), a 1,2,4-triazolopyridinyl-methanol derived analog, was identified as a potent and selective inhibitor of human 11ß-hydroxysteroid dehydrogenase type 1 (11ß-HSD-1) enzyme (IC50 = 2.3 nM) with >10,000-fold selectivity over 11ß-HSD-2. Compound 2 exhibits robust acute pharmacodynamic effects in cynomolgus monkeys (ED50 = 0.6 mg/kg) and in diet-induced obese (DIO) mice (ED50 = 34 mg/kg). Compound 2 also showed excellent inhibition in an ex vivo adipose DIO mouse model (ED50 = 5.2 mg/kg). Oral bioavailability ranges from 44% to 100% in preclinical species. Its favorable development properties, pharmacokinetics, high adipose-to-plasma concentration ratio, and preclinical pharmacology profile have prompted the evaluation of 2 for the treatment of type 2 diabetes and metabolic syndrome in phase 2 clinical trials.

Discovery of Clinical Candidate 2-((2S,6S)-2-Phenyl-6-hydroxyadamantan-2-yl)-1-(3'-hydroxyazetidin-1-yl)ethanone [BMS-816336], an Orally Active Novel Selective 11ß-Hydroxysteroid Dehydrogenase Type 1 Inhibitor.

BMS-816336 (6n-2), a hydroxy-substituted adamantyl acetamide, has been identified as a novel, potent inhibitor against human 11ß-hydroxysteroid dehydrogenase type 1 (11ß-HSD1) enzyme (IC50 3.0 nM) with >10000-fold selectivity over human 11ß-hydroxysteroid dehydrogenase type 2 (11ß-HSD2). 6n-2 exhibits a robust acute pharmacodynamic effect in cynomolgus monkeys (ED50 0.12 mg/kg) and in DIO mice. It is orally bioavailable (%F ranges from 20 to 72% in preclinical species) and has a predicted pharmacokinetic profile of a high peak to trough ratio and short half-life in humans. This ADME profile met our selection criteria for once daily administration, targeting robust inhibition of 11ß-HSD1 enzyme for the first 12 h period after dosing followed by an "inhibition holiday" so that the potential for hypothalamic-pituitary-adrenal (HPA) axis activation might be mitigated. 6n-2 was found to be well-tolerated in phase 1 clinical studies and represents a potential new treatment for type 2 diabetes, metabolic syndrome, and other human diseases modulated by glucocorticoid control.

Discovery and Preclinical Evaluation of BMS-711939, an Oxybenzylglycine Based PPARα Selective Agonist.

BMS-711939 (3) is a potent and selective peroxisome proliferator-activated receptor (PPAR) α agonist, with an EC50 of 4 nM for human PPARα and >1000-fold selectivity vs human PPARγ (EC50 = 4.5 µM) and PPARδ (EC50 > 100 µM) in PPAR-GAL4 transactivation assays. Compound 3 also demonstrated excellent in vivo efficacy and safety profiles in preclinical studies and thus was chosen for further preclinical evaluation. The synthesis, structure-activity relationship (SAR) studies, and in vivo pharmacology of 3 in preclinical animal models as well as its ADME profile are described.

Effects of in utero exposure of C57BL/6J mice to 2,3,7,8-tetrachlorodibenzo-p-dioxin on epidermal permeability barrier development and function.

BACKGROUND: Development of the epidermal permeability barrier (EPB) is essential for neonatal life. Defects in this barrier are found in many skin diseases such as atopic dermatitis. OBJECTIVE: We investigated the effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on the development and function of the EPB. METHODS: Timed-pregnant C57BL/6J mice were gavaged with corn oil or TCDD (10 µg/kg body weight) on gestation day 12. Embryos were harvested on embryonic day (E) 15, E16, E17, and postnatal day (PND) 1. RESULTS: A skin permeability assay showed that TCDD accelerated the development of the EPB, beginning at E15. This was accompanied by a significant decrease in transepidermal water loss (TEWL), enhanced stratification, and formation of the stratum corneum (SC). The levels of several ceramides were significantly increased at E15 and E16. PND1 histology revealed TCDD-induced acanthosis and epidermal hyperkeratosis. This was accompanied by disrupted epidermal tight junction (TJ) function, with increased dye leakage at the terminal claudin-1-staining TJs of the stratum granulosum. Because the animals did not have enhanced rates of TEWL, a commonly observed phenotype in animals with TJ defects, we performed tape-stripping. Removal of most of the SC resulted in a significant increase in TEWL in TCDD-exposed PND1 pups compared with their control group. CONCLUSIONS: These findings demonstrate that in utero exposure to TCDD accelerates the formation of an abnormal EPB with leaky TJs, warranting further study of environmental exposures, epithelial TJ integrity, and atopic disease.

Optimization of 1,2,4-Triazolopyridines as Inhibitors of Human 11ß-Hydroxysteroid Dehydrogenase Type 1 (11ß-HSD-1).

Small alkyl groups and spirocyclic-aromatic rings directly attached to the left side and right side of the 1,2,4-triazolopyridines (TZP), respectively, were found to be potent and selective inhibitors of human 11ß-hydroxysteroid dehydrogenase-type 1 (11ß-HSD-1) enzyme. 3-(1-(4-Chlorophenyl)cyclopropyl)-8-cyclopropyl-[1,2,4]triazolo[4,3-a]pyridine (9f) was identified as a potent inhibitor of the 11ß-HSD-1 enzyme with reduced Pregnane-X receptor (PXR) transactivation activity. The binding orientation of this TZP series was revealed by X-ray crystallography structure studies.

2,3,7,8-Tetrachlorodibenzo-p-dioxin-mediated production of reactive oxygen species is an essential step in the mechanism of action to accelerate human keratinocyte differentiation.

Chloracne is commonly observed in humans exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD); yet, the mechanism of toxicity is not well understood. Using normal human epidermal keratinocytes, we investigated the mechanism of TCDD-mediated enhancement of epidermal differentiation by integrating functional genomic, metabolomic, and biochemical analyses. TCDD increased the expression of 40% of the genes of the epidermal differentiation complex found on chromosome 1q21 and 75% of the genes required for de novo ceramide biosynthesis. Lipid analysis demonstrated that eight of the nine classes of ceramides were increased by TCDD, altering the ratio of ceramides to free fatty acids. TCDD decreased the expression of the glucose transporter, SLC2A1, and most of the glycolytic transcripts, followed by decreases in glycolytic intermediates, including pyruvate. NADH and Krebs cycle intermediates were decreased, whereas NAD(+) was increased. Mitochondrial glutathione (GSH) reductase activity and the GSH/glutathione disulfide ratio were decreased by TCDD, ultimately leading to mitochondrial dysfunction, characterized by decreased inner mitochondrial membrane potential and ATP production, and increased production of the reactive oxygen species (ROS), hydrogen peroxide. Aryl hydrocarbon receptor (AHR) antagonists blocked the response of many transcripts to TCDD, and the endpoints of decreased ATP production and differentiation, suggesting regulation by the AHR. Cotreatment of cells with chemical antioxidants or the enzyme catalase blocked the TCDD-mediated acceleration of keratinocyte cornified envelope formation, an endpoint of terminal differentiation. Thus, TCDD-mediated ROS production is a critical step in the mechanism of this chemical to accelerate keratinocyte differentiation.

Discovery of an oxybenzylglycine based peroxisome proliferator activated receptor alpha selective agonist 2-((3-((2-(4-chlorophenyl)-5-methyloxazol-4-yl)methoxy)benzyl)(methoxycarbonyl)amino)acetic acid (BMS-687453).

An 1,3-oxybenzylglycine based compound 2 (BMS-687453) was discovered to be a potent and selective peroxisome proliferator activated receptor (PPAR) alpha agonist, with an EC(50) of 10 nM for human PPARalpha and approximately 410-fold selectivity vs human PPARgamma in PPAR-GAL4 transactivation assays. Similar potencies and selectivity were also observed in the full length receptor co-transfection assays. Compound 2 has negligible cross-reactivity against a panel of human nuclear hormone receptors including PPARdelta. Compound 2 demonstrated an excellent pharmacological and safety profile in preclinical studies and thus was chosen as a development candidate for the treatment of atherosclerosis and dyslipidemia. The X-ray cocrystal structures of the early lead compound 12 and compound 2 in complex with PPARalpha ligand binding domain (LBD) were determined. The role of the crystal structure of compound 12 with PPARalpha in the development of the SAR that ultimately resulted in the discovery of compound 2 is discussed.

Amino(methyl) pyrrolidines as novel scaffolds for factor Xa inhibitors.

The design and synthesis of a novel class of amino(methyl) pyrrolidine-based sulfonamides as potent and selective FXa inhibitors is reported. The amino(methyl) pyrrolidine scaffolds were designed based on the proposed bioisosterism to the piperazine core in known FXa inhibitors. The SAR study led to compound 15 as the most potent FXa inhibitor in this series, with an IC(50) of 5.5 nM and PT EC(2x) of 1.7 microM. The proposed binding models show that the pyrrolidine cores are in van der Waals contact with the enzyme surface, and the flexibility of amino(methyl) pyrrolidines allows the two nitrogen atoms to anchor both the P1 and P4 groups to fit similarly in the S1 and S4 pockets.