N-Acylated and N-Alkylated 2-Aminobenzothiazoles Are Novel Agents That Suppress the Generation of Prostaglandin E2.

The quest for novel agents to regulate the generation of prostaglandin E2 (PGE2) is of high importance because this eicosanoid is a key player in inflammatory diseases. We synthesized a series of N-acylated and N-alkylated 2-aminobenzothiazoles and related heterocycles (benzoxazoles and benzimidazoles) and evaluated their ability to suppress the cytokine-stimulated generation of PGE2 in rat mesangial cells. 2-Aminobenzothiazoles, either acylated by the 3-(naphthalen-2-yl)propanoyl moiety (GK510) or N-alkylated by a chain carrying a naphthalene (GK543) or a phenyl moiety (GK562) at a distance of three carbon atoms, stand out in inhibiting PGE2 generation, with EC50 values ranging from 118 nM to 177 nM. Both GK510 and GK543 exhibit in vivo anti-inflammatory activity greater than that of indomethacin. Thus, N-acylated or N-alkylated 2-aminobenzothiazoles are novel leads for the regulation of PGE2 formation.

Synthesis of novel 2-pyrrolidinone and pyrrolidine derivatives and study of their inhibitory activity against autotaxin enzyme.

Autotaxin (ATX), a glycoprotein (~125 kDa) isolated as an autocrine motility factor from melanoma cells, belongs to a seven-membered family of ectonucleotide pyrophosphatase/phosphodiesterase (ENPP), and exhibits lysophospholipase D activity. ATX is responsible for the hydrolysis of lysophosphatidylcholine (LPC) to produce the bioactive lipid lysophosphatidic acid (LPA), which is upregulated in a variety of pathological inflammatory conditions, including fibrosis, cancer, liver toxicity and thrombosis. Given its role in human disease, the ATX-LPA axis is an interesting target for therapy, and the development of novel potent ATX inhibitors is of great importance. In the present work a novel class of ATX inhibitors, optically active derivatives of 2-pyrrolidinone and pyrrolidine heterocycles were synthesized. Some of them exhibited interesting in vitro activity, namely the hydroxamic acid 16 (IC50 700 nM) and the carboxylic acid 40b (IC50 800 nM), while the boronic acid derivatives 3k (IC50 50 nM), 3l (IC50 120 nM), 3 m (IC50 180 nM) and 21 (IC50 35 nM) were found to be potent inhibitors of ATX.

Small-molecule inhibitors as potential therapeutics and as tools to understand the role of phospholipases A2.

Phospholipase A2 (PLA2) enzymes are involved in various inflammatory pathological conditions including arthritis, cardiovascular and autoimmune diseases. The regulation of their catalytic activity is of high importance and a great effort has been devoted in developing synthetic inhibitors. We summarize the most important small-molecule synthetic PLA2 inhibitors developed to target each one of the four major types of human PLA2 (cytosolic cPLA2, calcium-independent iPLA2, secreted sPLA2, and lipoprotein-associated LpPLA2). We discuss recent applications of inhibitors to understand the role of each PLA2 type and their therapeutic potential. Potent and selective PLA2 inhibitors have been developed. Although some of them have been evaluated in clinical trials, none reached the market yet. Apart from their importance as potential medicinal agents, PLA2 inhibitors are excellent tools to unveil the role that each PLA2 type plays in cells and in vivo. Modern medicinal chemistry approaches are expected to generate improved PLA2 inhibitors as new agents to treat inflammatory diseases.

The Effect of Corticosteroids on Human Choroidal Endothelial Cells: A Model to Study Central Serous Chorioretinopathy.

Purpose: To isolate, culture, and characterize primary human choroidal endothelial cells, and to assess their responsiveness to corticosteroids, in order to enable knowledge gain on the pathogenesis of central serous chorioretinopathy. Methods: Choroidal endothelial cells were isolated from cadaveric human donors. Magnetic-activated cell sorting with anti-human CD31 was performed for choroidal endothelial cell isolation. Primary cultures of purified choroidal endothelial cells were treated with several regimens of corticosteroids and analyzed for effects on primary corticosteroid responsive genes. Results: Isolated choroidal endothelial cell cultures had a cobblestone appearance in monolayer cultures and stained positive for vascular endothelial cadherin. Moreover, on a 3D-Matrigel matrix, these cells formed capillary-like structures, characteristic of in vitro endothelial cells. Primary cultures of purified choroidal endothelial cells treated with several regimens of corticosteroids demonstrated significant transcriptional upregulation of primary corticosteroid responsive genes (FKBP5, PER1, GILZ, and SGK1). Further pharmacologic analysis using specific agonists (dexamethasone, aldosterone) and antagonists (mifepristone, spironolactone) for either the glucocorticoid receptor or the mineralocorticoid receptor showed that this response was exclusively mediated by the glucocorticoid receptor in our model. Conclusions: With this optimized choroidal endothelial cell isolation and culturing protocol, we have established an in vitro model that appears very suitable for research on both central serous chorioretinopathy and other diseases in which corticosteroids and choroidal endothelial cells are involved. Our model proves to be suitable for studying effects mediated through the glucocorticoid receptor. The role of mineralocorticoid receptor-mediated effects needs further research, both in vivo and in cell model development.

Hydroxamic Acids Constitute a Novel Class of Autotaxin Inhibitors that Exhibit in Vivo Efficacy in a Pulmonary Fibrosis Model.

Autotaxin (ATX) catalyzes the hydrolysis of lysophosphatidylcholine (LPC) generating the lipid mediator lysophosphatidic acid (LPA). Both ATX and LPA are involved in various pathological inflammatory conditions, including fibrosis and cancer, and have attracted great interest as medicinal targets over the past decade. Thus, the development of novel potent ATX inhibitors is of great importance. We have developed a novel class of ATX inhibitors containing the zinc binding functionality of hydroxamic acid. Such novel hydroxamic acids that incorporate a non-natural δ-amino acid residue exhibit high in vitro inhibitory potency over ATX (IC50 values 50-60 nM). Inhibitor 32, based on δ-norleucine, was tested for its efficacy in a mouse model of pulmonary inflammation and fibrosis induced by bleomycin and exhibited promising efficacy. The novel hydroxamic ATX inhibitors provide excellent tools for the study of the role of the enzyme and could contribute to the development of novel therapeutic agents for the treatment of fibrosis and other chronic inflammatory diseases.

Microsomal prostaglandin E2 synthase-1 inhibitors: a patent review.

INTRODUCTION: Microsomal prostaglandin E2 synthase-1 (mPGES-1) catalyzes the terminal step of prostaglandin E2 (PGE2) generation. It is strongly upregulated in inflamed tissues and overexpressed in tumors and it has been recognized as a key enzyme in inflammatory diseases such as arthritis, atherosclerosis, stroke and cancer. Thus, a great effort has been devoted in developing synthetic mPGES-1 inhibitors as novel anti-inflammatory agents. Areas covered: This review article summarizes the mPGES-1 inhibitors presented in patent literature from 2000 to August 2016 and their biological evaluation, discussing their activities in vitro and in vivo. Expert opinion: The side effects of NSAIDs and COX-2 inhibitors on the gastrointestinal tract and the cardiovascular system showcase the urgent need for the discovery of novel potent and safe anti-inflammatory drugs. mPGES-1 inhibitors may present superior safety in comparison to existing anti-inflammatory drugs. The first synthetic inhibitor of mPGES-1 was reported in 2001 and up to now a variety of structurally different inhibitors has been developed. However, only recently two inhibitors entered clinical trials and none has reached yet the market. More preclinical and clinical studies on mPGES-1 inhibitors are needed to realize if indeed they may become novel agents for the treatment of inflammation and cancer.

Autotaxin inhibitors: a patent review (2012-2016).

INTRODUCTION: Autotaxin (ATX) is a secreted enzyme that hydrolyzes lysophosphatidylcholine to lysophosphatidic acid (LPA) and choline. The ATX/LPA axis has received increasing interest in recent years because both the enzyme ATX and the bioactive lipid LPA are involved in various pathological conditions such as tumor progression and metastasis, fibrotic diseases, autoimmune diseases, arthritis, chronic hepatitis, obesity and impaired glucose homeostasis. Thus, a great effort has been devotd in developing synthetic ATX inhibitors as new agents to treat various diseases including cancer and fibrotic diseases. Areas covered: This review article summarizes the autotaxin inhibitors presented in patent literature from October 2012 to August 2016 and their biological evaluation, discussing their activities in vitro and in vivo. Expert opinion: During the recent years, there has been an intensive effort on the discovery of potent and selective ATX inhibitors. Although various synthetic inhibitors have been developed, only limited studies for their in vivo activity have been reported so far. A decade after the first claim of synthetic ATX inhibitors in 2006, one inhibitor has been in clinical trials for idiopapthic pulmonary fibrosis. The use of ATX inhibitors seems an attractive strategy to produce novel medicinal agents, for example anticancer agents.

Inhibitors of phospholipase A2 and their therapeutic potential: an update on patents (2012-2016).

INTRODUCTION: The regulation of the catalytic activity of the various phospholipase A2 enzymes is of high importance because these enzymes are involved in various pathological conditions such as arthritis, cardiovascular diseases, neurological diseases, and cancer. Thus, a great effort has been devoted in developing synthetic inhibitors as new agents to treat inflammatory diseases. Some of them have reached clinical trials. Areas covered: This review article discusses the phospholipase A2 inhibitors presented in patent literature from October 2012 to June 2016, their activities in vitro and in vivo as well as the results of clinical trials using synthetic PLA2 inhibitors. Expert opinion: None of the inhibitors studied in clinical trials have reached the market yet. The failure of lipoprotein-associated PLA2 inhibitor darapladib to reduce the risk of major coronary events suggests that this enzyme may be a biomarker of vascular inflammation rather than a causal pathway of cardiovascular diseases. These findings, together with the failure of secreted PLA2 inhibitor varespladib for the treatment of cardiovascular disease, indicate that deeper knowledge on these enzymes is needed. Inhibitors of cytosolic PLA2 are in clinical trials against psoriasis and atopic dermatitis.

2-Oxoamide inhibitors of cytosolic group IVA phospholipase A2 with reduced lipophilicity.

Cytosolic GIVA phospholipase A2 (GIVA cPLA2) initiates the eicosanoid pathway of inflammation and thus inhibitors of this enzyme constitute novel potential agents for the treatment of inflammatory diseases. Traditionally, GIVA cPLA2 inhibitors have suffered systemically from high lipophilicity. We have developed a variety of long chain 2-oxoamides as inhibitors of GIVA PLA2. Among them, AX048 was found to produce a potent analgesic effect. We have now reduced the lipophilicity of AX048 by replacing the long aliphatic chain with a chain containing an ether linked aromatic ring with in vitro inhibitory activities similar to AX048.

Metabolomic profiling to dissect the role of visceral fat in cardiometabolic health.

OBJECTIVE: Abdominal obesity is associated with increased risk of type 2 diabetes (T2D) and cardiovascular disease. The aim of this study was to assess whether metabolomic markers of T2D and blood pressure (BP) act on these traits via visceral fat (VF) mass. METHODS: Metabolomic profiling of 280 fasting plasma metabolites was conducted on 2,401 women from TwinsUK. The overlap was assessed between published metabolites associated with T2D, insulin resistance, or BP and those that were identified to be associated with VF (after adjustment for covariates) measured by dual-energy X-ray absorptiometry. RESULTS: In addition to glucose, six metabolites were strongly associated with both VF mass and T2D: lactate and branched-chain amino acids, all of them related to metabolism and the tricarboxylic acid cycle; on average, 38.5% of their association with insulin resistance was mediated by their association with VF mass. Five metabolites were associated with BP and VF mass including the inflammation-associated peptide HWESASXX, the steroid hormone androstenedione, lactate, and palmitate. On average, 29% of their effect on BP was mediated by their association with VF mass. CONCLUSIONS: Little overlap was found between the metabolites associated with BP and those associated with insulin resistance via VF mass.

New potent and selective polyfluoroalkyl ketone inhibitors of GVIA calcium-independent phospholipase A2.

Group VIA calcium-independent phospholipase A2 (GVIA iPLA2) has recently emerged as an important pharmaceutical target. Selective and potent GVIA iPLA2 inhibitors can be used to study its role in various neurological disorders. In the current work, we explore the significance of the introduction of a substituent in previously reported potent GVIA iPLA2 inhibitors. 1,1,1,2,2-Pentafluoro-7-(4-methoxyphenyl)heptan-3-one (GK187) is the most potent and selective GVIA iPLA2 inhibitor ever reported with a XI(50) value of 0.0001, and with no significant inhibition against GIVA cPLA2 or GV sPLA2. We also compare the inhibition of two difluoromethyl ketones on GVIA iPLA2, GIVA cPLA2, and GV sPLA2.