Pharmacology of a Potent and Novel Inhibitor of the NOD-Like Receptor Pyrin Domain-Containing Protein 3 (NLRP3) Inflammasome that Attenuates Development of Nonalcoholic Steatohepatitis and Liver Fibrosis.

The NOD-like receptor pyrin domain-containing protein 3 (NLRP3) inflammasome is a multiprotein complex and component of the innate immune system that is activated by exogenous and endogenous danger signals to promote activation of caspase-1 and the maturation and release of the proinflammatory cytokines interleukin (IL)-1ß and IL-18. Inappropriate activation of NLRP3 has been implicated in the pathophysiology of multiple inflammatory and autoimmune diseases, including cardiovascular disease, neurodegenerative diseases, and nonalcoholic steatohepatitis (NASH), thus increasing the clinical interest of this target. We describe in this study the preclinical pharmacologic, pharmacokinetic, and pharmacodynamic properties of a novel and highly specific NLRP3 inhibitor, JT001 (6,7-dihydro-5H-pyrazolo[5,1-b][1,3]oxazine-3-sulfonylurea). In cell-based assays, JT001 potently and selectively inhibited NLRP3 inflammasome assembly, resulting in the inhibition of cytokine release and the prevention of pyroptosis, a form of inflammatory cell death triggered by active caspase-1. Oral administration of JT001 to mice inhibited IL-1ß production in peritoneal lavage fluid at plasma concentrations that correlated with mouse in vitro whole blood potency. Orally administered JT001 was effective in reducing hepatic inflammation in three different murine models, including the Nlrp3A350V /+CreT model of Muckle-Wells syndrome (MWS), a diet-induced obesity NASH model, and a choline-deficient diet-induced NASH model. Significant reductions in hepatic fibrosis and cell damage were also observed in the MWS and choline-deficient models. Our findings demonstrate that blockade of NLRP3 attenuates hepatic inflammation and fibrosis and support the use of JT001 to investigate the role of NLRP3 in other inflammatory disease models. SIGNIFICANCE STATEMENT: Persistent inflammasome activation is the consequence of inherited mutations of NLRP3 and results in the development of cryopyrin-associated periodic syndromes associated with severe systemic inflammation. NLRP3 is also upregulated in nonalcoholic steatohepatitis, a metabolic chronic liver disease currently missing a cure. Selective and potent inhibitors of NLRP3 hold great promise and have the potential to overcome an urgent unmet need.

Lysyl oxidase like-2 contributes to renal fibrosis in Col4α3/Alport mice.

Lysyl oxidase like-2 (LOXL2) is an amine oxidase with both intracellular and extracellular functions. Extracellularly, LOXL2 promotes collagen and elastin crosslinking, whereas intracellularly, LOXL2 has been reported to modify histone H3, stabilize SNAIL, and reduce cell polarity. Although LOXL2 promotes liver and lung fibrosis, little is known regarding its role in renal fibrosis. Here we determine whether LOXL2 influences kidney disease in COL4A3 (-/-) Alport mice. These mice were treated with a small molecule inhibitor selective for LOXL2 or with vehicle and assessed for glomerular sclerosis and fibrosis, albuminuria, blood urea nitrogen, lifespan, pro-fibrotic gene expression and ultrastructure of the glomerular basement membrane. Laminin α2 deposition in the glomerular basement membrane and mesangial filopodial invasion of the glomerular capillaries were also assessed. LOXL2 inhibition significantly reduced interstitial fibrosis and mRNA expression of MMP-2, MMP-9, TGF-ß1, and TNF-α. LOXL2 inhibitor treatment also reduced glomerulosclerosis, expression of MMP-10, MMP-12, and MCP-1 mRNA in glomeruli, and decreased albuminuria and blood urea nitrogen. Mesangial filopodial invasion of the capillary tufts was blunted, as was laminin α2 deposition in the glomerular basement membrane, and glomerular basement membrane ultrastructure was normalized. There was no effect on lifespan. Thus, LOXL2 plays an important role in promoting both glomerular and interstitial pathogenesis associated with Alport syndrome in mice. Other etiologies of chronic kidney disease are implicated with our observations.

Selective Inhibition of Autotaxin Is Efficacious in Mouse Models of Liver Fibrosis.

Autotaxin (ATX) is a secreted glycoprotein that converts lysophosphatidylcholine (LPC) to the bioactive phospholipid lysophosphatidic acid (LPA) and is the major enzyme generating circulating LPA. Inhibition of LPA signaling has profound antifibrotic effects in multiple organ systems, including lung, kidney, skin, and peritoneum. However, other LPA-generating pathways exist, and the role of ATX in localized tissue LPA production and fibrosis remains unclear and controversial. In this study, we describe the preclinical pharmacologic, pharmacokinetic, and pharmacodynamic properties of a novel small-molecule ATX inhibitor, PAT-505 [3-((6-chloro-2-cyclopropyl-1-(1-ethyl-1H-pyrazol-4-yl)-7-fluoro-1H-indol-3-yl) thio)-2-fluorobenzoic acid sodium salt]. PAT-505 is a potent, selective, noncompetitive inhibitor that displays significant inhibition of ATX activity in plasma and liver tissue after oral administration. When dosed therapeutically in a Stelic Mouse Animal Model of nonalcoholic steatohepatitis (NASH), PAT-505 treatment resulted in a small but significant improvement in fibrosis with only minor improvements in hepatocellular ballooning and hepatic inflammation. In a choline-deficient, high-fat diet model of NASH, therapeutic treatment with PAT-505 robustly reduced liver fibrosis with no significant effect on steatosis, hepatocellular ballooning, or inflammation. These data demonstrate that inhibiting autotaxin is antifibrotic and may represent a novel therapeutic approach for the treatment of multiple fibrotic liver diseases, including NASH.

Autotaxin activity increases locally following lung injury, but is not required for pulmonary lysophosphatidic acid production or fibrosis.

Lysophosphatidic acid (LPA) is an important mediator of pulmonary fibrosis. In blood and multiple tumor types, autotaxin produces LPA from lysophosphatidylcholine (LPC) via lysophospholipase D activity, but alternative enzymatic pathways also exist for LPA production. We examined the role of autotaxin (ATX) in pulmonary LPA production during fibrogenesis in a bleomycin mouse model. We found that bleomycin injury increases the bronchoalveolar lavage (BAL) fluid levels of ATX protein 17-fold. However, the LPA and LPC species that increase in BAL of bleomycin-injured mice were discordant, inconsistent with a substrate-product relationship between LPC and LPA in pulmonary fibrosis. LPA species with longer chain polyunsaturated acyl groups predominated in BAL fluid after bleomycin injury, with 22:5 and 22:6 species accounting for 55 and 16% of the total, whereas the predominant BAL LPC species contained shorter chain, saturated acyl groups, with 16:0 and 18:0 species accounting for 56 and 14% of the total. Further, administration of the potent ATX inhibitor PAT-048 to bleomycin-challenged mice markedly decreased ATX activity systemically and in the lung, without effect on pulmonary LPA or fibrosis. Therefore, alternative ATX-independent pathways are likely responsible for local generation of LPA in the injured lung. These pathways will require identification to therapeutically target LPA production in pulmonary fibrosis.-Black, K. E., Berdyshev, E., Bain, G., Castelino, F. V., Shea, B. S., Probst, C. K., Fontaine, B. A., Bronova, I., Goulet, L., Lagares, D., Ahluwalia, N., Knipe, R. S., Natarajan, V., Tager, A. M. Autotaxin activity increases locally following lung injury, but is not required for pulmonary lysophosphatidic acid production or fibrosis.

Structural Basis for Inhibition of Human Autotaxin by Four Potent Compounds with Distinct Modes of Binding.

Autotaxin (ATX) is a secreted enzyme that hydrolyzes lysophosphatidylcholine to lysophosphatidic acid (LPA). LPA is a bioactive phospholipid that regulates diverse biological processes, including cell proliferation, migration, and survival/apoptosis, through the activation of a family of G protein-coupled receptors. The ATX-LPA pathway has been implicated in many pathologic conditions, including cancer, fibrosis, inflammation, cholestatic pruritus, and pain. Therefore, ATX inhibitors represent an attractive strategy for the development of therapeutics to treat a variety of diseases. Mouse and rat ATX have been crystallized previously with LPA or small-molecule inhibitors bound. Here, we present the crystal structures of human ATX in complex with four previously unpublished, structurally distinct ATX inhibitors. We demonstrate that the mechanism of inhibition of each compound reflects its unique interactions with human ATX. Our studies may provide a basis for the rational design of novel ATX inhibitors.

Pharmacodynamics, pharmacokinetics and safety of GSK2190915, a novel oral anti-inflammatory 5-lipoxygenase-activating protein inhibitor.

AIM: To assess the pharmacokinetics, pharmacodynamics, safety and tolerability of the 5-lipoxygenase-activating protein inhibitor, GSK2190915, after oral dosing in two independent phase I studies, one in Western European and one in Japanese subjects, utilizing different formulations. METHOD: Western European subjects received single (50-1000 mg) or multiple (10-450 mg) oral doses of GSK2190915 or placebo in a dose-escalating manner. Japanese subjects received three of four GSK2190915 doses (10-200 mg) plus placebo once in a four period crossover design. Blood samples were collected for GSK2190915 concentrations and blood and urine were collected to measure leukotriene B4 and leukotriene E4, respectively, as pharmacodynamic markers of drug activity. RESULTS: There was no clear difference in adverse events between placebo and active drug-treated subjects in either study. Maximum plasma concentrations of GSK2190915 and area under the curve increased in a dose-related manner and mean half-life values ranged from 16-34 h. Dose-dependent inhibition of blood leukotriene B4 production was observed and near complete inhibition of urinary leukotriene E4 excretion was shown at all doses except the lowest dose. The EC50 values for inhibition of LTB4 were 85 nM and 89 nM in the Western European and Japanese studies, respectively. CONCLUSION: GSK2190915 is well-tolerated with pharmacokinetics and pharmacodynamics in Western European and Japanese subjects that support once daily dosing for 24 h inhibition of leukotrienes. Doses of ≥50 mg show near complete inhibition of urinary leukotriene E4 at 24 h post-dose, whereas doses of ≥150 mg are required for 24 h inhibition of blood LTB4.

JT002, a small molecule inhibitor of the NLRP3 inflammasome for the treatment of autoinflammatory disorders.

The NLRP3 inflammasome is an intracellular, multiprotein complex that promotes the auto-catalytic activation of caspase-1 and the subsequent maturation and secretion of the pro-inflammatory cytokines, IL-1ß and IL-18. Persistent activation of the NLRP3 inflammasome has been implicated in the pathophysiology of a number of inflammatory and autoimmune diseases, including neuroinflammation, cardiovascular disease, non-alcoholic steatohepatitis, lupus nephritis and severe asthma. Here we describe the preclinical profile of JT002, a novel small molecule inhibitor of the NLRP3 inflammasome. JT002 potently reduced NLRP3-dependent proinflammatory cytokine production across a number of cellular assays and prevented pyroptosis, an inflammatory form of cell death triggered by active caspase-1. JT002 demonstrated in vivo target engagement at therapeutically relevant concentrations when orally dosed in mice and prevented body weight loss and improved inflammatory and fibrotic endpoints in a model of Muckle-Wells syndrome (MWS). In two distinct models of neutrophilic airway inflammation, JT002 treatment significantly reduced airway hyperresponsiveness and airway neutrophilia. These results provide a rationale for the therapeutic targeting of the NLRP3 inflammasome in severe asthma and point to the use of JT002 in a variety of inflammatory disorders.

Amelioration of dermal fibrosis by genetic deletion or pharmacologic antagonism of lysophosphatidic acid receptor 1 in a mouse model of scleroderma.

OBJECTIVE: Scleroderma (systemic sclerosis [SSc]), is characterized by progressive multiorgan fibrosis. We recently implicated lysophosphatidic acid (LPA) in the pathogenesis of pulmonary fibrosis. The purpose of the present study was to investigate the roles of LPA and two of its receptors, LPA1 and LPA2, in dermal fibrosis in a mouse model of SSc. METHODS: Wild type (WT), and LPA1-knockout (KO) and LPA2-KO mice were injected subcutaneously with bleomycin or phosphate buffered saline (PBS) once daily for 28 days. Dermal thickness, collagen content, and numbers of cells positive for α-smooth muscle actin (α-SMA) or phospho-Smad2 were determined in bleomycin-injected and PBS-injected skin. In separate experiments, a novel selective LPA1 antagonist AM095 or vehicle alone was administered by oral gavage to C57BL/6 mice that were challenged with 28 daily injections of bleomycin or PBS. AM095 or vehicle treatments were initiated concurrently with, or 7 or 14 days after, the initiation of bleomycin and PBS injections and continued to the end of the experiments. Dermal thickness and collagen content were determined in injected skin. RESULTS: The LPA1 -KO mice were markedly resistant to bleomycin-induced increases in dermal thickness and collagen content, whereas the LPA2-KO mice were as susceptible as the WT mice. Bleomycin-induced increases in dermal α-SMA+ and phospho-Smad2+ cells were abrogated in LPA1-KO mice. Pharmacologic antagonism of LPA1 with AM095 significantly attenuated bleomycin-induced dermal fibrosis when administered according to either a preventive regimen or two therapeutic regimens. CONCLUSION: These results suggest that LPA/LPA1 pathway inhibition has the potential to be an effective new therapeutic strategy for SSc, and that LPA1 is an attractive pharmacologic target in dermal fibrosis.

Overcoming Preclinical Safety Obstacles to Discover (S)-N-((1,2,3,5,6,7-Hexahydro-s-indacen-4-yl)carbamoyl)-6-(methylamino)-6,7-dihydro-5H-pyrazolo[5,1-b][1,3]oxazine-3-sulfonamide (GDC-2394): A Potent and Selective NLRP3 Inhibitor.

Inappropriate activation of the NLRP3 inflammasome has been implicated in multiple inflammatory and autoimmune diseases. Herein, we aimed to develop novel NLRP3 inhibitors that could minimize the risk of drug-induced liver injury. Lipophilic ligand efficiency was used as a guiding metric to identify a series of 6,7-dihydro-5H-pyrazolo[5,1-b][1,3]oxazinesulfonylureas. A leading compound from this series was advanced into safety studies in cynomolgus monkeys, and renal toxicity, due to compound precipitation, was observed. To overcome this obstacle, we focused on improving the solubility of our compounds, specifically by introducing basic amine substituents into the scaffold. This led to the identification of GDC-2394, a potent and selective NLRP3 inhibitor, with an in vitro and in vivo safety profile suitable for advancement into human clinical trials.

Pharmacology of AM211, a potent and selective prostaglandin D2 receptor type 2 antagonist that is active in animal models of allergic inflammation.

The prostaglandin D(2) (PGD(2)) receptor type 2 (DP2) is a G protein-coupled receptor that has been shown to be involved in a variety of allergic diseases, including allergic rhinitis, asthma, and atopic dermatitis. In this study, we describe the preclinical pharmacological and pharmacokinetic properties of the small-molecule DP2 antagonist [2'-(3-benzyl-1-ethyl-ureidomethyl)-6-methoxy-4'-trifluoromethyl-biphenyl-3-yl]-acetic acid (AM211). We determine that AM211 has high affinity for human, mouse, rat, and guinea pig DP2 and it shows selectivity over other prostanoid receptors and enzymes. Antagonist activity of AM211 at the DP2 receptor was confirmed by inhibition of PGD(2)-stimulated guanosine 5'-O-[γ-thio]triphosphate binding to membranes expressing human DP2. A basophil activation assay and a whole-blood assay of eosinophil shape change were used to demonstrate the ability of AM211 to potently antagonize PGD(2)-stimulated functional responses in relevant human cells and in the context of a physiologically relevant environment. AM211 exhibits good oral bioavailability in rats and dogs and dose-dependently inhibits 13,14-dihydro-15-keto-PGD(2)-induced leukocytosis in a guinea pig pharmacodynamic assay. AM211 demonstrates efficacy in two animal models of allergic inflammation, including an ovalbumin-induced lung inflammation model in guinea pigs and an ovalbumin-induced mouse model of allergic rhinitis. AM211 represents a potent and selective antagonist of DP2 that may be used clinically to evaluate the role of DP2 in T helper 2-driven allergic inflammatory diseases.

Discovery and optimization of a biphenylacetic acid series of prostaglandin D2 receptor DP2 antagonists with efficacy in a murine model of allergic rhinitis.

Biphenylacetic acid (5) was identified through a library screen as an inhibitor of the prostaglandin D(2) receptor DP2 (CRTH2). Optimization for potency and pharmacokinetic properties led to a series of selective CRTH2 antagonists. Compounds demonstrated potency in a human DP2 binding assay and a human whole blood eosinophil shape change assay, as well as good oral bioavailability in rat and dog, and efficacy in a mouse model of allergic rhinitis following oral dosing.

Sodium [2'-[(cyclopropanecarbonyl-ethyl-amino)-methyl]-4'-(6-ethoxy-pyridin-3-yl)-6-methoxy-biphenyl-3-yl]-acetate (AM432): a potent, selective prostaglandin D2 receptor antagonist.

Compound 21 (AM432) was identified as a potent and selective antagonist of the DP(2) receptor (CRTH2). Modification of a bi-aryl core identified a series of tri-aryl antagonists of which compound 21 proved a viable clinical candidate. AM432 shows excellent potency in a human whole blood eosinophil shape change assay with prolonged incubation, a comparatively long off-rate from the DP(2) receptor, excellent pharmacokinetics in dog and in vivo activity in two mouse models of inflammatory disease after oral dosing.

Pharmacological blockade of the DP2 receptor inhibits cigarette smoke-induced inflammation, mucus cell metaplasia, and epithelial hyperplasia in the mouse lung.

Prostaglandin D(2) (PGD(2)) is one of a family of biologically active lipids derived from arachidonic acid via the action of COX-1 and COX-2. PGD(2) is released from mast cells and binds primarily to two G protein-coupled receptors, namely DP1 and DP2, the latter also known as chemoattractant receptor-homologous molecule expressed on Th2 cells. DP2 is predominantly expressed on eosinophils, Th2 cells, and basophils, but it is also expressed to a lesser extent on monocytes, mast cells, and epithelial cells. Interaction of PGD(2) and its active metabolites with DP2 results in cellular chemotaxis, degranulation, up-regulation of adhesion molecules, and cytokine production. Chronic obstructive pulmonary disease (COPD) is a chronic progressive inflammatory disease characterized by elevated lung neutrophils, macrophages, and CD8+ T lymphocytes and mucus hypersecretion. Cigarette smoke contributes to the etiology of COPD and was used here as a provoking agent in a murine model of COPD. In an acute model, {2'-[(cyclopropanecarbonyl-ethyl-amino)-methyl]-6-methoxy-4'-trifluoro-methyl-biphenyl-3-yl}-acetic acid, sodium salt (AM156) and (5-{2-[(benzoyloxycarbonyl-ethyl-amino)-methyl]-4-trifluoromethyl-phenyl}-pyridin-3-yl)-acetic acid, sodium salt) (AM206), potent DP2 receptor antagonists, dose-dependently inhibited influx of neutrophils and lymphocytes to smoke-exposed airways. In a subchronic model, AM156 and AM206 inhibited neutrophil and lymphocyte trafficking to the airways. Furthermore, AM156 and AM206 treatment inhibited mucus cell metaplasia and prevented the thickening of the airway epithelial layer induced by cigarette smoke. These data suggest that DP2 receptor antagonism may represent a novel therapy for COPD or other conditions characterized by neutrophil influx, mucus hypersecretion, and airway remodeling.

5-Lipoxygenase-activating protein inhibitors. Part 3: 3-{3-tert-Butylsulfanyl-1-[4-(5-methoxy-pyrimidin-2-yl)-benzyl]-5-(5-methyl-pyridin-2-ylmethoxy)-1H-indol-2-yl]-2,2-dimethyl-propionic acid (AM643)-A potent FLAP inhibitor suitable for topical administration.

AM643 (compound 6, 3-{3-tert-butylsulfanyl-1-[4-(5-methoxy-pyrimidin-2-yl)-benzyl]-5-(5-methyl-pyridin-2-ylmethoxy)-1H-indol-2-yl]-2,2-dimethyl-propionic acid) was identified as a potential candidate for formulation as a topical agent for the treatment of skin disorders involving leukotriene production. Dermal application of 6 using a prototypical vehicle in a murine ear arachidonic acid model showed significant reduction in the concentrations of leukotrienes in mouse skin with concomitant reduction in ear swelling.

5-Lipoxygenase-activating protein inhibitors. Part 2: 3-{5-((S)-1-Acetyl-2,3-dihydro-1H-indol-2-ylmethoxy)-3-tert-butylsulfanyl-1-[4-(5-methoxy-pyrimidin-2-yl)-benzyl]-1H-indol-2-yl}-2,2-dimethyl-propionic acid (AM679)--a potent FLAP inhibitor.

A series of potent 5-lipoxygenase-activating protein (FLAP) inhibitors are herein described. SAR studies focused on the discovery of novel alicyclic moieties appended to an indole core to optimize potency, physical properties and off-target activities. Subsequent SAR on the N-benzyl substituent of the indole led to the discovery of compound 39 (AM679) which showed potent inhibition of leukotrienes in human blood and in a rodent bronchoalvelolar lavage (BAL) challenge model.

Pharmacological characterization of 3-[3-tert-butylsulfanyl-1-[4-(6-methoxy-pyridin-3-yl)-benzyl]-5-(pyridin-2-ylmethoxy)-1H-indol-2-yl]-2,2-dimethyl-propionic acid (AM103), a novel selective 5-lipoxygenase-activating protein inhibitor that reduces acute and chronic inflammation.

Leukotrienes (LTs) are proinflammatory lipid mediators synthesized by the conversion of arachidonic acid (AA) to LTA(4) by the enzyme 5-lipoxygenase (5-LO) in the presence of 5-LO-activating protein (FLAP). 3-[3-tert-Butylsulfanyl-1-[4-(6-methoxy-pyridin-3-yl)-benzyl]-5-(pyridin-2-ylmethoxy)-1H-indol-2-yl]-2,2-dimethyl-propionic acid (AM103) is a novel selective FLAP inhibitor in development for the treatment of respiratory conditions such as asthma. In a rat ex vivo whole-blood calcium ionophore-induced LTB(4) assay, AM103 (administered orally at 1 mg/kg) displayed >50% inhibition for up to 6 h with a calculated EC(50) of approximately 60 nM. When rat lung was challenged in vivo with calcium ionophore, AM103 inhibited LTB(4) and cysteinyl leukotriene (CysLT) production with ED(50) values of 0.8 and 1 mg/kg, respectively. In this model, the EC(50) derived from plasma AM103 was approximately 330 nM for inhibition of both LTB(4) and CysLT. In an acute inflammation setting, AM103 displayed dose-dependent inhibition of LTB(4), CysLT, and plasma protein extravasation induced by peritoneal zymosan injection. In a model of chronic lung inflammation using ovalbumin-primed and challenged BALB/c mice, AM103 reduced the concentrations of eosinophil peroxidase, CysLTs, and interleukin-5 in the bronchoalveolar lavage fluid. Finally, AM103 increased survival time in mice exposed to a lethal intravenous injection of platelet-activating factor. In summary, AM103 is a novel, potent and selective FLAP inhibitor that has excellent pharmacodynamic properties in vivo and is effective in animal models of acute and chronic inflammation and in a model of lethal shock.

Novel tricyclic antagonists of the prostaglandin D2 receptor DP2 with efficacy in a murine model of allergic rhinitis.

The synthesis of a series of tricyclic antagonists for the prostaglandin D(2) receptor DP2 (CRTH2) is disclosed. The activities of the compounds were evaluated in a human DP2 binding assay and a human whole blood eosinophil shape change assay. Potential metabolic liabilities of the compounds were addressed through in vitro CYP studies. The lead compound was demonstrated to have efficacy in a mouse model of allergic rhinitis following oral dosing.

The involvement of autotaxin in renal interstitial fibrosis through regulation of fibroblast functions and induction of vascular leakage.

The accumulation of fibroblasts is a critical step in the development of fibrosis, and lysophosphatidic acid (LPA) promotes fibrosis by regulating multiple fibroblast functions. Autotaxin (ATX) is a key LPA-producing enzyme, and we hypothesized that ATX contributes to the development of renal interstitial fibrosis through LPA-mediated effects on fibroblast functions. In a mouse model of renal interstitial fibrosis induced by unilateral ureteral obstruction (UUO), the levels of renal ATX protein and activity increased with the progression of fibrosis in ligated kidneys, despite concurrent reductions in renal ATX mRNA. UUO enhanced vascular permeability in the renal interstitium, and ATX protein localized to areas of vascular leak, suggesting that vascular leak allowed ATX to enter the renal interstitium. In vitro studies showed that ATX induces the migration and proliferation of renal fibroblasts and enhances the vascular permeability of endothelial monolayers. Finally, pharmacological inhibition of ATX partially attenuated renal interstitial fibrosis. These results suggest that during the development of renal fibrosis, ATX accumulates in the renal interstitium and drives fibroblast accumulation and promotes renal interstitial vascular leak, thereby partially contributing to the pathogenesis of renal interstitial fibrosis. Taken together, ATX inhibition may have the potential to be a novel therapeutic strategy to combat renal interstitial fibrosis.

Small Molecule Lysyl Oxidase-like 2 (LOXL2) Inhibitors: The Identification of an Inhibitor Selective for LOXL2 over LOX.

Two series of novel LOXL2 enzyme inhibitors are described: benzylamines substituted with electron withdrawing groups at the para-position and 2-substituted pyridine-4-ylmethanamines. The most potent compound, (2-chloropyridin-4-yl)methanamine 20 (hLOXL2 IC50 = 126 nM), was shown to be selective for LOXL2 over LOX and three other amine oxidases (MAO-A, MAO-B, and SSAO). Compound 20 is the first published small molecule inhibitor selective for LOXL2 over LOX.