Characterisation and Profiling of Standard Atopic Dermatitis Therapies in a Chronic Dermatitis Murine Model Induced by Oxazolone.

Atopic dermatitis (AD) is a common inflammatory skin disorder characterised by hypersensitivity to allergens, eczematous lesions and pruritus. The aim of this study was to comprehensively characterise a murine model of dermatitis and assess the similarity with the human disease, as well as to profile clinically relevant AD therapies. Four repeated topical administrations of oxazolone in the auricular skin of sensitised mice induced morphological features compatible with AD, including redness and swelling, as well as histological changes typical of spongiotic (eczematous) dermatitis and increased plasmatic IgE.

Pharmacological characterization of a novel peptide inhibitor of the Keap1-Nrf2 protein-protein interaction.

LAS200813 is a novel bicyclic lipopeptide that activates Nrf2 by binding to Keap1, thereby antagonising the Keap1-Nrf2 protein-protein interaction. In this work we report the pharmacological characterization of LAS200813 in Nrf2-dependent translational preclinical models. LAS200813 binds to Keap1 with high affinity (IC: 0.

Identification of 2-Imidazopyridine and 2-Aminopyridone Purinones as Potent Pan-Janus Kinase (JAK) Inhibitors for the Inhaled Treatment of Respiratory Diseases.

Janus kinases (JAKs) have a key role in regulating the expression and function of relevant inflammatory cytokines involved in asthma and chronic obstructive pulmonary disease. Herein are described the design, synthesis, and pharmacological evaluation of a series of novel purinone JAK inhibitors with profiles suitable for inhaled administration. Replacement of the imidazopyridine hinge binding motif present in the initial compounds of this series with a pyridone ring resulted in the mitigation of cell cytotoxicity.

Novel Inhaled Pan-JAK Inhibitor, LAS194046, Reduces Allergen-Induced Airway Inflammation, Late Asthmatic Response, and pSTAT Activation in Brown Norway Rats.

The Janus-activated kinase (JAK) family together with signal transducer and activator of transcription (STAT) signaling pathway has a key role in regulating the expression and function of many inflammatory cytokines. This has led to the discovery of JAK inhibitors for the treatment of inflammatory diseases, some of them already in the market. Considering the adverse effects associated with JAK inhibition by oral route, we wanted to explore whether JAK inhibition by inhaled route is enough to inhibit airway inflammation.

Discovery of a Novel Inhaled PI3Kδ Inhibitor for the Treatment of Respiratory Diseases.

Oral PI3Kδ inhibitors such as Idelalisib and Duvelisib have shown efficacy as anticancer agents and Idelalisib has been approved for the treatment of three B-cell cancers. However, Idelalisib has a black box warning on its product label regarding the risks of fatal and serious toxicities including hepatic toxicity, severe diarrhea, colitis, pneumonitis, infections, and intestinal perforation. Some of these side effects are mechanism-related and could hinder the development of Idelalisib for less severe conditions.

4-Amino-7,8-dihydro-1,6-naphthyridin-5(6 H)-ones as Inhaled Phosphodiesterase Type 4 (PDE4) Inhibitors: Structural Biology and Structure-Activity Relationships.

Rational design of a novel template of naphthyridinones rapidly led to PDE4 inhibitors with subnanomolar enzymatic potencies. X-ray crystallography confirmed the binding mode of this novel template. We achieved compounds with double-digit picomolar enzymatic potencies through further structure-based design by targeting both the PDE4 enzyme metal-binding pocket and occupying the solvent-filled pocket.

Discovery of a Potent, Selective, and Orally Available PI3Kδ Inhibitor for the Treatment of Inflammatory Diseases.

The delta isoform of the phosphatidylinositol 3-kinase (PI3Kδ) has been shown to have an essential role in specific immune cell functions and thus represents a potential therapeutic target for autoimmune and inflammatory diseases. Herein, the optimization of a series of pyrrolotriazinones as potent and selective PI3Kδ inhibitors is described. The main challenge of the optimization process was to identify an orally available compound with a good pharmacokinetic profile in preclinical species that predicted a suitable dosing regimen in humans.

Tofacitinib ameliorates inflammation in a rat model of airway neutrophilia induced by inhaled LPS.

Background And Purpose: The Janus Kinase (JAK) family mediates the cytokine receptor-induced signalling pathways involved in inflammatory processes. The activation of the signal transducers and activators of transcription (STATs) by JAK kinases is a key point in these pathways. Four JAK proteins, JAK1, JAK2, JAK3 and tyrosine kinase 2 (Tyk2) associate with the intracellular domains of surface cytokine receptors are phosphorylating STATs and modulating gene expression.

Biphenyl Pyridazinone Derivatives as Inhaled PDE4 Inhibitors: Structural Biology and Structure-Activity Relationships.

Cyclic nucleotide cAMP is a ubiquitous secondary messenger involved in a plethora of cellular responses to biological agents involving activation of adenylyl cyclase. Its intracellular levels are tightly controlled by a family of cyclic nucleotide degrading enzymes, the PDEs. In recent years, cyclic nucleotide phosphodiesterase type 4 (PDE4) has aroused scientific attention as a suitable target for anti-inflammatory therapy in respiratory diseases, particularly in the management of asthma and COPD.

Combined anti CXC receptors 1 and 2 therapy is a promising anti-inflammatory treatment for respiratory diseases by reducing neutrophil migration and activation.

Neutrophil infiltration and activation in the lung are important pathophysiological features in COPD, severe asthma and bronchiectasis mostly mediated by CXCL8 and CXCL1 via CXCR1 and CXCR2. No thorough study to date has been performed to compare the anti-inflammatory effect profile of dual CXCR1/2 vs. selective CXCR2 antagonists in relevant human neutrophil assays and pulmonary inflammation models.

Double-stranded RNA evokes exacerbation in a mouse model of corticosteroid refractory asthma.

RNA viruses are a major cause of respiratory infections and are known to exacerbate asthma and other respiratory diseases. Our aim was to test the ability of poly(I:C) (polyinosinic:polycytidylic acid), a viral surrogate, to elicit exacerbation in a model of severe asthma driven by HDM (house dust mite) in FCA (Freund's complete adjuvant). Poly(I:C) was administered intranasally around the HDM challenge in FCA-HDM-sensitized animals.

The in vitro and in vivo profile of aclidinium bromide in comparison with glycopyrronium bromide.

This study characterised the in vitro and in vivo profiles of two novel long-acting muscarinic antagonists, aclidinium bromide and glycopyrronium bromide, using tiotropium bromide and ipratropium bromide as comparators. All four antagonists had high affinity for the five muscarinic receptor sub-types (M1-M5); aclidinium had comparable affinity to tiotropium but higher affinity than glycopyrronium and ipratropium for all receptors. Glycopyrronium dissociated faster from recombinant M3 receptors than aclidinium and tiotropium but more slowly than ipratropium; all four compounds dissociated more rapidly from M2 receptors than from M3 receptors.

Synthesis and biological activity of pyrido[3',2':4,5]furo[3,2-d]pyrimidine derivatives as novel and potent phosphodiesterase type 4 inhibitors.

A series of pyrido[3',2':4,5]furo[3,2-d]pyrimidines (PFP) were synthesized and tested for phosphodiesterase type 4 (PDE4) inhibitory activity, with the potential to treat asthma and chronic obstructive pulmonary disease (COPD). Structure-activity relationships within this series, leading to an increase of potency on the enzyme, is presented. Both gem-dimethylcyclohexyl moieties fused to the pyridine ring and the substitution at the 5 position of the PFP scaffold, proved to be key elements in order to get a high affinity in the enzyme.

Discovery of substituted phenyl urea derivatives as novel long-acting β2-adrenoreceptor agonists.

The synthesis of diverse functionalized ureas in a semi-parallel fashion is described, as well as their β(1)/β(2)-adrenergic activities and the corresponding structure-activity relationship (SAR). We have focused on lipophilicity and duration of action, and we have discovered a strong correlation in this series of molecules. A quantitative structure-activity relationship (QSAR) analysis will be presented that quantifies this relationship.

Effect of 5-hydroxytryptamine on neurogenic vasoconstriction in the isolated, autoperfused hindquarters of the rat.

1. In the present study, we analysed the effect of different doses of 5-hydroxytryptamine (5-HT; intravenous infusions of 0.001-40 microg/kg per min) in the autoperfused hindquarters of the rat subjected to electrical stimulation (frequencies of 0.

Diabetes-induced changes in the 5-hydroxytryptamine inhibitory receptors involved in the pressor effect elicited by sympathetic stimulation in the pithed rat.

1. We investigated the effect of alloxan-induced diabetes on the inhibitory mechanisms of 5-hydroxytryptamine (5-HT) in the pressor responses induced by stimulation of sympathetic vasopressor outflow in pithed rats, and analysed the type and/or subtype of 5-HT receptors involved. 2.

m-CPP, a 5-HT2C receptor agonist that modifies the perfusion pressure of the hindquarter vascular bed of anesthetized rat.

In the present work we studied the actions of the intra-arterial administration of meta-chlorophenylpiperazine (m-CPP - a 5-HT(2C) receptor agonist) in the hindquarters of the anesthetized rat. The lowest doses used (0.001, 0.

Vasoconstrictor responses to 5-hydroxytryptamine in the autoperfused hindquarters of spontaneously hypertensive rats.

In this work we studied the responses and receptors involved in the effects of intra-arterial 5-hydroxytryptamine (5-HT) in the in situ autoperfused hindquarters of spontaneously hypertensive rats (SHR). Intra-arterial administration of the highest doses (50-1,000 ng/kg) produced a vasoconstrictor effect that was inhibited by ritanserin (a selective 5-HT2 receptor antagonist), SB 206553 (a selective 5-HT(2B/2C) receptor antagonist) and spiperone (a nonspecific 5-HT(1/2A) receptor antagonist), and was mimicked by alpha-methyl-5-HT (a selective 5-HT2 receptor agonist) and m-CPP (a selective 5-HT2C receptor agonist), but not by the intra-arterial administration of BW 723C86, a selective 5HT2B receptor agonist. SB 206553 and spiperone inhibited alpha-methyl-5HT-induced vasoconstriction in the hindquarters of SHR.

5-Hydroxytryptamine-induced vasodilator responses in the hindquarters of the anaesthetized rat, involve beta2-adrenoceptors.

These studies were conducted to examine the role of the vasoactive mediators nitric oxide (NO) and adrenaline (epinephrine) in the serotonin (5-hydroxytryptamine; 5-HT)-induced vasodilator response in the hindquarter vascular bed of anaesthetized rats. Intra-arterial administration of doses of 5-HT in the range 0.12-25 ng kg(-1) produced a dose-independent vasodilator effect in the hindquarters.

Vasodilator and vasoconstrictor responses induced by 5-hydroxytryptamine in the in situ blood autoperfused hindquarters of the anaesthetized rat.

In the present study we attempted to characterise the responses and receptors involved in the effects of 5-hydroxytryptamine (5-HT, serotonin) in in situ autoperfused rat hindquarters. Intra-arterial administration of the lowest doses of 5-HT used (0.12-12.

Characterization of mechanisms involved in presynaptic inhibition of sympathetic pressor effects induced by some 5-HT1 receptor antagonists.

1. In a previous study, we showed that the presynaptic inhibitory action of 5-hydroxytryptamine receptor agonists on sympathetic pressor effects obtained in the pithed rats were mainly mediated by activation of 5-HT1A and 5-HT1D receptor subtypes. At the time, we observed that some 5-HT1 receptors antagonists - WAY 100,635 and NAN-190 (both 5-HT1A receptor antagonists), methiothepin (a 5-HT1,2,5,6,7 receptor antagonist) and spiperone (a 5-HT1,2 receptor antagonist) - reduced per se the pressor effects obtained by electrical stimulation.