Dual bronchodilatory and pulmonary anti-inflammatory activity of RO5024118, a novel agonist at vasoactive intestinal peptide VPAC2 receptors

BACKGROUND AND PURPOSE

Vasoactive intestinal peptide is expressed in the respiratory tract and induces its effects via its receptors, VPAC₁ and VPAC₂. RO5024118 is a selective VPAC₂ receptor agonist derived via chemical modification of an earlier VPAC₂ agonist, RO0251553. In the present studies, we characterized the pharmacological activity of RO5024118.

EXPERIMENTAL APPROACH

Stability of RO5024118 to human neutrophil elastase was assessed. Bronchodilatory activity of RO5024118 was investigated in guinea pig and human isolated airway smooth muscle preparations and in a guinea pig bronchoconstriction model. Pulmonary anti-inflammatory activity of RO5024118 was investigated in a lipopolysaccharide mouse model and in a porcine pancreatic elastase (PPE) rat model.

KEY RESULTS

RO5024118 demonstrated increased stability to neutrophil elastase compared with RO0251553. In human and guinea pig isolated airway preparations, RO5024118 induced bronchodilatory effects comparable with RO0251553 and the long-acting β-agonist salmeterol and was significantly more potent than native vasoactive intestinal peptide and the short-acting β-agonist salbutamol. In 5-HT-induced bronchoconstriction in guinea pigs, RO5024118 exhibited inhibitory activity with similar efficacy as, and longer duration than, RO0251553. In a lipopolysaccharide-mouse model, RO5024118 inhibited neutrophil and CD8⁺ cells and myeloperoxidase levels. In rats, intratracheal instillation of PPE induced airway neutrophilia that was resistant to dexamethasone. Pretreatment with RO5024118 significantly inhibited PPE-induced neutrophil accumulation.

CONCLUSIONS AND IMPLICATIONS

These results demonstrate that RO5024118 induces dual bronchodilatory and pulmonary anti-inflammatory activity and may be beneficial in treating airway obstructive and inflammatory diseases.     

Differential actions of urocortins on neurons of the myenteric division of the enteric nervous system in guinea pig distal colon

Background and purpose:

Urocortins (Ucns) 1, 2 and 3 are corticotropin-releasing factor (CRF)-related neuropeptides and may be involved in neural regulation of colonic motor functions. Nevertheless, details of the neural mechanism of action for Ucns have been unclear. We have, here, tested the hypothesis that Ucns act in the enteric nervous system (ENS) to influence colonic motor behaviour.

Experimental approach:

We used intracellular recording with ‘sharp’ microelectrodes, followed by intraneuronal injection of biocytin, and immunohistochemical localization of CRF₁ and CRF₂ receptors in guinea pig colonic tissue.

Key results:

Application of Ucn1 depolarized membrane potentials and elevated excitability in 58% of AH-type and 60% of S-type colonic myenteric neurons. In most of the neurons tested, depolarizing responses evoked by Ucn-1 were suppressed by the CRF₁ receptor antagonist NBI 27914, but were unaffected by the CRF₂ receptor antagonist antisauvagine-30. The selective CRF₂ receptor agonists, Ucn2 and Ucn3, evoked depolarizing responses in 12 and 8% of the AH-type myenteric neurons, respectively, and had no effect on S-type neurons. Antisauvagine-30, but not NBI 27914, suppressed these Ucn2- and Ucn3-evoked responses. Immunohistochemical staining identified CRF₁ as the predominant CRF receptor subtype expressed by ganglion cell somas, while CRF₂-immunoreactive neuronal somas were sparse. Ucns did not affect excitatory synaptic transmission in the ENS.

Conclusions and implications:

The results suggest that Ucns act as neuromodulators to influence myenteric neuronal excitability. The excitatory action of Ucn1 in myenteric neurons was primarily at CRF₁ receptors, and the excitatory action of Ucn2 and Ucn3 was at CRF₂ receptors.     

WAY-318068: a novel, potent and selective noradrenaline re-uptake inhibitor with activity in rodent models of pain and depression

Background and purpose:

Antidepressants, which raise the CNS concentrations of 5-HT and noradrenaline, are frequently used in the treatment of chronic pain; however, it is not known if increasing CNS noradrenaline levels alone is sufficient for efficacy, in part resulting from a lack of small molecules with sufficient selectivity.

Experimental approach:

In this report, we present the in vitro pharmacological and in vivo pharmacokinetic and pharmacological properties of the novel, orally available and CNS penetrant inhibitor of the noradrenaline transporter (NET), WAY-318068 (1-[(1S,2R)-1-(3,5-difluorophenyl)-2-hydroxy-3-(methylamino)propyl]-7-fluoro-3,3-dimethyl-1,3-dihydro-2H-indol-2-one).

Key results:

WAY-318068 is a potent and effective inhibitor of the NET with a K_i of 8.7 nM in a binding assay, and an IC₅₀ of 6.8 nM in an assay of transporter function, without significant binding to the dopamine transporter. Furthermore, the compound has only weak activity at the 5-HT transporter, leading to a functional selectivity of greater than 2500-fold. It is orally bioavailable with substantial quantities of the compound found in the CNS after oral dosing. As measured by microdialysis in rats, the compound causes a robust and significant increase in cortical noradrenaline levels without affecting 5-HT. WAY-318068 was effective in models of acute, visceral, inflammatory, osteoarthritic, neuropathic, diabetic and bone cancer pain, as well as in traditional models of depression at doses that do not cause motor deficits.

Conclusions and implications:

Collectively, the present results support the conclusion that selectively increasing CNS levels of noradrenaline is sufficient for efficacy in models of depression and pain.     

Highlights of the 2017 European AIDS Clinical Society (EACS) Guidelines for the treatment of adult HIV‐positive persons version 9.0

Background

The European AIDS Clinical Society (EACS) Guidelines have since 2005 provided multidisciplinary recommendations for the care of HIV‐positive persons in geographically diverse areas.

Guideline highlights

Major revisions have been made in all sections of the 2017 Guidelines: antiretroviral treatment (ART), comorbidities, coinfections and opportunistic diseases. Newly added are also a summary of the main changes made, and direct video links to the EACS online course on HIV Management. Recommendations on the clinical situations in which tenofovir alafenamide may be considered over tenofovir disoproxil fumarate are provided, and recommendations on which antiretrovirals can be used safely during pregnancy have been revised. Renal and bone toxicity and hepatitis C virus (HCV) treatment have been added as potential reasons for ART switches in fully virologically suppressed individuals, and dolutegravir/rilpivirine has been included as a treatment option. In contrast, dolutegravir monotherapy is not recommended. New recommendations on non‐alcoholic fatty liver disease, chronic lung disease, solid organ transplantation, and prescribing in elderly are included, and human papilloma virus (HPV) vaccination recommendations have been expanded. All drug–drug interaction tables have been updated and new tables are included. Treatment options for direct‐acting antivirals (DAAs) have been updated and include the latest combinations of sofosbuvir/velpatasvir/voxilaprevir and glecaprevir/pibrentasvir. Recommendations on management of DAA failure and acute HCV infection have been expanded. For treatment of tuberculosis (TB), it is underlined that intermittent treatment is contraindicated, and for resistant TB new data suggest that using a three‐drug combination may be as effective as a five‐drug regimen, and may reduce treatment duration from 18‐24 to 6‐10 months.

Conclusions

Version 9.0 of the EACS Guidelines provides a holistic approach to HIV care and is translated into the six most commonly spoken languages.