In vitro sepsis up-regulates Nociceptin/Orphanin FQ receptor expression and function on human T- but not B-cells.

Background And Purpose: In animal models of sepsis, increased activation of the Nociceptin/Orphanin FQ (N/OFQ) receptor NOP is associated with mortality and NOP antagonists improved survival. We have explored the role of the N/OFQ-NOP system in freshly isolated volunteer human B- and T-cells incubated with lipopolysaccharide (LPS) and peptidoglycan G (PepG) as a model of in vitro sepsis.

Experimental Approach: B- and T-cell NOP expression was measured using the NOP fluorescent probe N/OFQ , N/OFQ content was measured using immunofluorescence, N/OFQ release was tracked using a CHO biosensor assay and NOP function was measured using transwell migration and cytokine/chemokine release using a 25-plex assay format.

In vitro sepsis induces Nociceptin/Orphanin FQ receptor (NOP) expression in primary human vascular endothelial but not smooth muscle cells.

Sepsis is a dysregulated host response to infection that can cause widespread effects on other organs including cardiovascular depression, hypotension and organ failure. The receptor for Nociceptin/Orphanin FQ (N/OFQ), NOP is expressed on immune cells and these cells can release the peptide. Exogenous N/OFQ can dilate blood vessels and this peptide is increased in animal and human sepsis.

Opioids and cancer survival: are we looking in the wrong place?

There is a controversial narrative in the anaesthetic literature suggesting that anaesthetic technique (including opioids) may be detrimental to survival after tumour resection. The initial observations were retrospective. Several prospective studies are ongoing; one in breast cancer has reported no adverse outcome.

Fluorescent opioid receptor ligands as tools to study opioid receptor function.

Opioid receptors are divided into the three classical types: MOP(μ:mu), DOP(δ:delta) and KOP(κ:kappa) that are naloxone-sensitive and an additional naloxone-insensitive nociceptin/orphanin FQ(N/OFQ) peptide receptor(NOP). Studies to determine opioid receptor location and turnover variably rely on; (i) measuring receptor mRNA, (ii) genetically tagging receptors, (iii) labelling receptors with radioligands, (iv) use of antibodies in immunohistochemistry/Western Blotting or (v) measuring receptor function coupled with the use of selective antagonists. All have their drawbacks with significant issues relating to mRNA not necessarily predicting protein, poor antibody selectivity and utility of radiolabels in low expression systems.

Evaluation of [Cys(ATTO 488)8]Dermorphin-NH2 as a novel tool for the study of μ-opioid peptide receptors.

The μ-opioid peptide (MOP) receptor is a member of the opioid receptor family and an important clinical target for analgesia. Measuring MOP receptor location and tracking its turnover traditionally used radiolabels or antibodies with attendant problems of utility of radiolabels in whole cells and poor antibody selectivity. To address these issues we have synthesized and characterised a novel ATTO488 based fluorescent Dermorphin analogue; [Cys(ATTO 488)8]Dermorphin-NH2 (DermATTO488).

N/OFQ-NOP System in Peripheral and Central Immunomodulation.

Classical opioids (μ: mu, MOP; δ: delta, DOP and κ: kappa, KOP) variably affect immune function; they are immune depressants and there is good clinical evidence in the periphery. In addition, there is evidence for a central role in the control of a number of neuropathologies, e.g.

In vitro pharmacological characterization of a novel unbiased NOP receptor-selective nonpeptide agonist AT-403.

Nociceptin/orphanin FQ (N/OFQ) regulates several biological functions via selective activation of the N/OFQ receptor (NOP), a member of the opioid receptor family. We recently identified a new high affinity and highly selective NOP agonist AT-403. In this study, we characterized the functional profile of AT-403 and compared it to other known nonpeptide NOP agonists Ro 65-6570, Ro 2q, SCH-221510, MCOPPB, AT-202 and SCH-486757, using the following assays: GTPγ[ S] stimulated binding, calcium mobilization assay in cells-expressing human NOP or classical opioid receptors and chimeric G proteins, bioluminescence resonance energy transfer (BRET) based assay for studying NOP receptor interaction with G protein and arrestin, and the electrically stimulated mouse vas deferens bioassay.

Pharmacological studies on the NOP and opioid receptor agonist PWT2-[Dmt]N/OFQ(1-13).

An innovative chemical strategy named peptide welding technology (PWT) has been developed for the facile synthesis of tetrabranched peptides. [Dmt]N/OFQ(1-13)-NH acts as a universal agonist for nociceptin/orphanin FQ (N/OFQ) and classical opioid receptors. The present study investigated the pharmacological profile of the PWT derivative of [Dmt]N/OFQ(1-13)NH (PWT2-[Dmt]) in several assays in vitro and in vivo after spinal administration in monkeys subjected to the tail withdrawal assay.

Characterisation of the Novel Mixed Mu-NOP Peptide Ligand Dermorphin-N/OFQ (DeNo).

Introduction: Opioid receptors are currently classified as Mu (μ), Delta (δ), Kappa (κ) plus the opioid related nociceptin/orphanin FQ (N/OFQ) peptide receptor (NOP). Despite compelling evidence for interactions and benefits of targeting more than one receptor type in producing analgesia, clinical ligands are Mu agonists. In this study we have designed a Mu-NOP agonist named DeNo.

Simultaneous targeting of multiple opioid receptor types.

Purpose Of Review: This article aims to discuss the multitarget concept for opioid receptor ligands framed on early observations that activating MOP (mu:μ) receptor whilst simultaneously blocking DOP (delta:δ) receptors reduces the onset of morphine tolerance. The review period is ostensibly calendar year 2014 but the new work in 2013 is also covered.

Recent Findings: Two molecules of interest with MOP agonist/DOP agonist and MOP agonist/DOP antagonist profiles were described: Rv-Jim-C3 and 3-[(2R,6R,11R)-8-hydroxy-6,11-dimethyl-1,4,5,6-tetrahydro-2,6-methano-3-benzazocin-3(2H)-yl]-N-phenylpropanamide (LP1), respectively.

Structure activity studies of nociceptin/orphanin FQ(1-13)-NH2 derivatives modified in position 5.

Nociceptin/orphanin FQ (N/OFQ) is a heptadecapeptide acting as the endogenous ligand of the N/OFQ peptide receptor (NOP). N/OFQ(1-13)-NH2 is the shortest N/OFQ sequence maintaining the same potency and efficacy as the natural peptide. Thus N/OFQ(1-13)-NH2 was used as chemical template for investigating the structure activity relationship of threonine in position 5.