Cytokine induced 3-D organotypic psoriasis skin model demonstrates distinct roles for NF-κB and JAK pathways in disease pathophysiology.

Psoriasis vulgaris is an inflammatory skin disease that affects 2%-3% of the population worldwide. One of the major challenges in discovering novel therapies is the poor translatability of animal models to human disease. Therefore, it is imperative to develop human preclinical models of psoriasis that are amenable to pharmacological intervention.

Small Molecule IL-36γ Antagonist as a Novel Therapeutic Approach for Plaque Psoriasis.

IL-36 cytokines are pro-inflammatory members of the IL-1 family that are upregulated in inflammatory disorders. Specifically, IL-36γ is highly expressed in active psoriatic lesions and can drive pro-inflammatory processes in 3D human skin equivalents supporting a role for this target in skin inflammation. Small molecule antagonists of interleukins have been historically challenging to generate.

Small Molecule and Pooled CRISPR Screens Investigating IL17 Signaling Identify BRD2 as a Novel Contributor to Keratinocyte Inflammatory Responses.

Interleukin-17A (IL17A) plays a critical role in the development of numerous autoimmune diseases, including psoriasis. The clinical success of IL17A neutralizing biologics in psoriasis has underlined its importance as a drug discovery target. While many studies have focused on the differentiation and trafficking of IL17A producing T-helper 17 cells, less is known about IL17A-initiated signaling events in stromal and parenchymal cells leading to psoriatic phenotypes.

TRPV1 ligands with hyperthermic, hypothermic and no temperature effects in rats.

Transient receptor potential vanilloid 1 (TRPV1) is a multifunctional ion channel playing important roles in a numerous biological processes including the regulation of body temperature. Within distinct and tight chemical space of chromanyl ureas TRPV1 ligands were identified that exhibit distinctive pharmacology and a spectrum of thermoregulatory effects ranging from hypothermia to hyperthermia. The ability to manipulate these effects by subtle structural modifications of chromanyl ureas may serve as a productive approach in TRPV1 drug discovery programs addressing either side effect or desired target profiles of the compounds.

Synthesis and Pharmacology of (Pyridin-2-yl)methanol Derivatives as Novel and Selective Transient Receptor Potential Vanilloid 3 Antagonists.

Transient receptor potential vanilloid 3 (TRPV3) is a Ca(2+)- and Na(+)-permeable channel with a unique expression pattern. TRPV3 is found in both neuronal and non-neuronal tissues, including dorsal root ganglia, spinal cord, and keratinocytes. Recent studies suggest that TRPV3 may play a role in inflammation, pain sensation, and skin disorders.

Discovery of (R)-1-(7-chloro-2,2-bis(fluoromethyl)chroman-4-yl)-3-(3-methylisoquinolin-5-yl)urea (A-1165442): a temperature-neutral transient receptor potential vanilloid-1 (TRPV1) antagonist with analgesic efficacy.

The synthesis and characterization of a series of selective, orally bioavailable 1-(chroman-4-yl)urea TRPV1 antagonists is described. Whereas first-generation antagonists that inhibit all modes of TRPV1 activation can elicit hyperthermia, the compounds disclosed herein do not elevate core body temperature in preclinical models and only partially block acid activation of TRPV1. Advancing the SAR of this series led to the eventual identification of (R)-1-(7-chloro-2,2-bis(fluoromethyl)chroman-4-yl)-3-(3-methylisoquinolin-5-yl)urea (A-1165442, 52), an analogue that possesses excellent pharmacological selectivity, has a favorable pharmacokinetic profile, and demonstrates good efficacy against osteoarthritis pain in rodents.

Pharmacology of modality-specific transient receptor potential vanilloid-1 antagonists that do not alter body temperature.

The transient receptor potential vanilloid-1 (TRPV1) channel is involved in the development and maintenance of pain and participates in the regulation of temperature. The channel is activated by diverse agents, including capsaicin, noxious heat (≥ 43°C), acidic pH (< 6), and endogenous lipids including N-arachidonoyl dopamine (NADA). Antagonists that block all modes of TRPV1 activation elicit hyperthermia.

Selective blockade of TRPA1 channel attenuates pathological pain without altering noxious cold sensation or body temperature regulation.

Despite the increasing interest in TRPA1 channel as a pain target, its role in cold sensation and body temperature regulation is not clear; the efficacy and particularly side effects resulting from channel blockade remain poorly understood. Here we use a potent, selective, and bioavailable antagonist to address these issues. A-967079 potently blocks human (IC(50): 51 nmol/L, electrophysiology, 67 nmol/L, Ca(2+) assay) and rat TRPA1 (IC(50): 101 nmol/L, electrophysiology, 289 nmol/L, Ca(2+) assay).

Chroman and tetrahydroquinoline ureas as potent TRPV1 antagonists.

Novel chroman and tetrahydroquinoline ureas were synthesized and evaluated for their activity as TRPV1 antagonists. It was found that aryl substituents on the 7- or 8-position of both bicyclic scaffolds imparted the best in vitro potency at TRPV1. The most potent chroman ureas were assessed in chronic and acute pain models, and compounds with the ability to cross the blood-brain barrier were shown to be highly efficacious.

Synthesis and biological evaluation of 5-substituted and 4,5-disubstituted-2-arylamino oxazole TRPV1 antagonists.

The synthesis and structure-activity relationships of a series of 5-monosubstituted and 4,5-disubstituted 2-arylaminooxazoles as novel antagonists of the transient receptor potential vanilloid 1 (TRPV1) receptor are described. The 7-hydroxy group of the tetrahydronaphthyl moiety on the 2-amino substituent of the oxazole ring was important for obtaining excellent in vitro potency at the human TRPV1 receptor, while a variety of alkyl and phenyl substituents at the 4- and 5-positions of the oxazole ring were well tolerated and yielded potent TRPV1 antagonists. Despite excellent in vitro potency, the 5-monosubstituted compounds suffered from poor pharmacokinetics.

Discovery of TRPV1 antagonist ABT-116.

The synthesis and SAR of a series of indazole TRPV1 antagonists leading to the discovery of 21 (ABT-116) is described. Biological studies demonstrated potent in vitro and in vivo activity for 21, as well as suitable physicochemical and pharmacokinetic properties for advancement to clinical development for pain management.

Expression and purification of human TRPV1 in baculovirus-infected insect cells for structural studies.

TRPV1 is a ligand-gated cation channel that is involved in acute thermal nociception and neurogenic inflammation. By using the GP67 signal peptide, high levels of full-length human TRPV1 was expressed in High Five insect cells using the baculovirus expression system. The functional activity of the expressed TRPV1 was confirmed by whole-cell ligand-gated ion flux recordings in the presence of capsaicin and low pH and via specific ligand binding to the isolated cellular membranes.

Characterization of A-425619 at native TRPV1 receptors: a comparison between dorsal root ganglia and trigeminal ganglia.

1-isoquinolin-5-yl-3-(4-trifluoromethyl-benzyl)-urea (A-425619), a novel, potent, and selective transient receptor potential type V1 (TRPV1) antagonist, attenuates pain associated with inflammation and tissue injury in rats. The purpose of this study was to extend the in vitro characterization of A-425619 to native TRPV1 receptors and to compare the pharmacological properties of TRPV1 receptors in the dorsal root ganglion with trigeminal ganglion neurons. A robust increase in intracellular Ca(2+) was elicited by a variety of TRPV1 agonists with similar rank order of potency between both cultures: resiniferatoxin>tinyatoxin>capsaicin>N-arachidonoyl-dopamine (NADA).

Tetrahydropyridine-4-carboxamides as novel, potent transient receptor potential vanilloid 1 (TRPV1) antagonists.

A series of 1,2,3,6-tetrahydropyridyl-4-carboxamides, exemplified by 6, have been synthesized and evaluated for in vitro TRPV1 antagonist activity, and in vivo analgesic activity in animal pain models. The tetrahydropyridine 6 is a novel TRPV1 receptor antagonist that potently inhibits receptor-mediated Ca2+ influx in vitro induced by several agonists, including capsaicin, N-arachidonoyldopamine (NADA), and low pH. This compound penetrates the CNS and shows potent anti-nociceptive effects in a broad range of animal pain models upon oral dosing due in part to its ability to antagonize both central and peripheral TRPV1 receptors.

(R)-(5-tert-butyl-2,3-dihydro-1H-inden-1-yl)-3-(1H-indazol-4-yl)-urea (ABT-102) blocks polymodal activation of transient receptor potential vanilloid 1 receptors in vitro and heat-evoked firing of spinal dorsal horn neurons in vivo.

The transient receptor potential vanilloid (TRPV) 1 receptor, a nonselective cation channel expressed on peripheral sensory neurons and in the central nervous system, plays a key role in pain. TRPV1 receptor antagonism is a promising approach for pain management. In this report, we describe the pharmacological and functional characteristics of a structurally novel TRPV1 antagonist, (R)-(5-tert-butyl-2,3-dihydro-1H-inden-1-yl)-3-(1H-indazol-4-yl)-urea (ABT-102), which has entered clinical trials.

Identification of (R)-1-(5-tert-butyl-2,3-dihydro-1H-inden-1-yl)-3-(1H-indazol-4-yl)urea (ABT-102) as a potent TRPV1 antagonist for pain management.

Vanilloid receptor TRPV1 is a cation channel that can be activated by a wide range of noxious stimuli, including capsaicin, acid, and heat. Blockade of TRPV1 activation by selective antagonists is under investigation by several pharmaceutical companies in an effort to identify novel agents for pain management. Here we report that replacement of substituted benzyl groups by an indan rigid moiety in a previously described N-indazole- N'-benzyl urea series led to a number of TRPV1 antagonists with significantly increased in vitro potency and enhanced drug-like properties.

[3H]A-778317 [1-((R)-5-tert-butyl-indan-1-yl)-3-isoquinolin-5-yl-urea]: a novel, stereoselective, high-affinity antagonist is a useful radioligand for the human transient receptor potential vanilloid-1 (TRPV1) receptor.

1-((R)-5-tert-butyl-indan-1-yl)-3-isoquinolin-5-yl-urea (A-778317) is a novel, stereoselective, competitive antagonist that potently blocks transient receptor potential vanilloid-1 (TRPV1) receptor-mediated changes in intracellular calcium concentrations (pIC50 = 8.31 +/- 0.13).

In vitro structure-activity relationship and in vivo characterization of 1-(aryl)-3-(4-(amino)benzyl)urea transient receptor potential vanilloid 1 antagonists.

The synthesis and structure-activity relationship of 1-(aryl)-3-(4-(amino)benzyl)urea transient receptor potential vanilloid 1 (TRPV1) antagonists are described. A variety of cyclic amine substituents are well tolerated at the 4-position of the benzyl group on compounds containing either an isoquinoline or indazole heterocyclic core. These compounds are potent antagonists of capsaicin activation of the TRPV1 receptor in vitro.

Alpha-methylation at benzylic fragment of N-aryl-N'-benzyl ureas provides TRPV1 antagonists with better pharmacokinetic properties and higher efficacy in inflammatory pain model.

SAR studies for N-aryl-N'-benzyl urea class of TRPV1 antagonists have been extended to cover alpha-benzyl alkylation. Alkylated compounds showed weaker in vitro potencies in blocking capsaicin activation of TRPV1 receptor, but possessed improved pharmacokinetic properties. Further structural manipulations that included replacement of isoquinoline core with indazole and isolation of single enantiomer led to TRPV1 antagonists like (R)-16a with superior pharmacokinetic properties and greater potency in animal model of inflammatory pain.

Capsaicin causes protein synthesis inhibition and microtubule disassembly through TRPV1 activities both on the plasma membrane and intracellular membranes.

TRPV1 is a non-selective cationic channel that is activated by capsaicin, acidic pH and thermal stimuli. Sustained TRPV1 channel activation causes severe cytotoxicity that leads to cell death. In this study, we investigated the mechanisms of capsaicin-induced cytotoxicity in HEK293 cells stably expressing TRPV1 with a focus on protein synthesis regulation and cytoskeleton reorganization.

TRPV1b overexpression negatively regulates TRPV1 responsiveness to capsaicin, heat and low pH in HEK293 cells.

Transient receptor potential channel type V (TRPV) 1 is a non-selective cation channel that can be activated by capsaicin, endogenous vanilloids, heat and protons. The human TRPV1 splice variant, TRPV1b, lacking exon 7, was cloned from human dorsal root ganglia (DRG) RNA. The expression profile and relative abundance of TRPV1b and TRPV1 in 35 different human tissues were determined by quantitative RT-PCR using isoform-specific probes.

Structure-activity studies of a novel series of 5,6-fused heteroaromatic ureas as TRPV1 antagonists.

Novel 5,6-fused heteroaromatic ureas were synthesized and evaluated for their activity as TRPV1 antagonists. It was found that 4-aminoindoles and indazoles are the preferential cores for the attachment of ureas. Bulky electron-withdrawing groups in the para-position of the aromatic ring of the urea substituents imparted the best in vitro potency at TRPV1.

Endogenous opioid mechanisms partially mediate P2X3/P2X2/3-related antinociception in rat models of inflammatory and chemogenic pain but not neuropathic pain.

P2X3/P2X2/3 receptors have emerged as important components of nociception. However, there is limited information regarding the neurochemical systems that are affected by antagonism of the P2X3/P2X2/3 receptor and that ultimately contribute to the ensuing antinociception. In order to determine if the endogenous opioid system is involved in this antinociception, naloxone was administered just prior to the injection of a selective P2X3/P2X2/3 receptor antagonist, A-317491, in rat models of neuropathic, chemogenic, and inflammatory pain.

A-425619 [1-isoquinolin-5-yl-3-(4-trifluoromethyl-benzyl)-urea], a novel and selective transient receptor potential type V1 receptor antagonist, blocks channel activation by vanilloids, heat, and acid.

The vanilloid receptor transient receptor potential type V1 (TRPV1) integrates responses to multiple stimuli, such as capsaicin, acid, heat, and endovanilloids and plays an important role in the transmission of inflammatory pain. Here, we report the identification and in vitro characterization of A-425619 [1-isoquinolin-5-yl-3-(4-trifluoromethyl-benzyl)-urea], a novel, potent, and selective TRPV1 antagonist. A-425619 was found to potently block capsaicin-evoked increases in intracellular calcium concentrations in HEK293 cells expressing recombinant human TRPV1 receptors (IC50 = 5 nM).

Novel transient receptor potential vanilloid 1 receptor antagonists for the treatment of pain: structure-activity relationships for ureas with quinoline, isoquinoline, quinazoline, phthalazine, quinoxaline, and cinnoline moieties.

Novel transient receptor potential vanilloid 1 (TRPV1) receptor antagonists with various bicyclic heteroaromatic pharmacophores were synthesized, and their in vitro activity in blocking capsaicin activation of TRPV1 was assessed. On the basis of the contribution of these pharmacophores to the in vitro potency, they were ranked in the order of 5-isoquinoline > 8-quinoline = 8-quinazoline > 8-isoquinoline > or = cinnoline approximately phthalazine approximately quinoxaline approximately 5-quinoline. The 5-isoquinoline-containing compound 14a (hTRPV1 IC50 = 4 nM) exhibited 46% oral bioavailability and in vivo activity in animal models of visceral and inflammatory pain.