AChBP-targeted α-conotoxin correlates distinct binding orientations with nAChR subtype selectivity

Neuronal nAChRs are a diverse family of pentameric ion channels with wide distribution throughout cells of the nervous and immune systems. However, the role of specific subtypes in normal and pathological states remains poorly understood due to the lack of selective probes. Here, we used a binding assay based on acetylcholine-binding protein (AChBP), a homolog of the nicotinic acetylcholine ligand-binding domain, to discover a novel α-conotoxin (α-TxIA) in the venom of Conus textile. α-TxIA bound with high affinity to AChBPs from different species and selectively targeted the α3β2 nAChR subtype. A co-crystal structure of Ac-AChBP with the enhanced potency analog TxIA(A10L), revealed a 20° backbone tilt compared to other AChBP–conotoxin complexes. This reorientation was coordinated by a key salt bridge formed between Arg5 (TxIA) and Asp195 (Ac-AChBP). Mutagenesis studies, biochemical assays and electrophysiological recordings directly correlated the interactions observed in the co-crystal structure to binding affinity at AChBP and different nAChR subtypes. Together, these results establish a new pharmacophore for the design of novel subtype-selective ligands with therapeutic potential in nAChR-related diseases

Molecular mechanism for analgesia involving specific antagonism of α9α10 nicotinic acetylcholine receptors

α9α10 nicotinic acetylcholine receptors (nAChRs) have been identified in a variety of tissues including lymphocytes and dorsal root ganglia; except in the case of the auditory system, the function of α9α10 nAChRs is not known. Here we show that selective block (rather than stimulation) of α9α10 nAChRs is analgesic in an animal model of nerve injury pain. In addition, blockade of this nAChR subtype reduces the number of choline acetyltransferase-positive cells, macrophages, and lymphocytes at the site of injury. Chronic neuropathic pain is estimated to affect up to 8% of the world's population; the numerous analgesic compounds currently available are largely ineffective and act through a small number of pharmacological mechanisms. Our findings not only suggest a molecular mechanism for the treatment of neuropathic pain but also demonstrate the involvement of α9α10 nAChRs in the pathophysiology of peripheral nerve injury

Respiratory syncytial virus infection, TLR3 ligands, and proinflammatory cytokines induce CD161 ligand LLT1 expression on the respiratory epithelium

D. Lyles (Editeur)During respiratory-virus infection, excessive lymphocyte activation can cause pathology both in acute infection and in exacerbations of chronic respiratory diseases. The costimulatory molecule CD161 is expressed on lymphocyte subsets implicated in promoting respiratory inflammation, including Th2, Th17, mucosally associated invariant T (MAIT) cells, and type 2 innate lymphoid cells. We asked whether the CD161 ligand LLT1 could be expressed on respiratory epithelial cells following respiratory-virus infection as a mechanism by which respiratory-virus infection could promote activation of proinflammatory lymphocytes. In response to respiratory syncytial virus (RSV) infection, expression of LLT1 was upregulated in the BEAS-2B respiratory epithelial cell line and primary human bronchial epithelial cells. Imaging studies revealed that LLT1 expression increased in both RSV-infected and cocultured uninfected cells, suggesting that soluble factors produced during infection stimulate LLT1 expression. TLR3 and TLR2/6 ligands led to a rapid increase in LLT1 mRNA in respiratory epithelial cells, as did the proinflammatory cytokines type I interferons, interleukin 1 beta (IL-1 beta), and tumor necrosis factor alpha (TNF-alpha), which are produced early in respiratory-virus infection. Immunohistochemistry confirmed the increase in LLT1 protein on the epithelial cell surface, and live-cell confocal microscopy demonstrated accumulation of epithelial LLT1 at synapses formed with CD161(+) T lymphocytes. LLT1 expression by the respiratory epithelium in response to respiratory-virus infection and inflammatory cytokines represents a novel link between innate immunity and lymphocyte activation. As a regulator of CD161(+) proinflammatory lymphocytes, LLT1 could be a novel therapeutic target in inflammation caused by respiratory-virus infection

A novel mechanism of inhibition of high-voltage activated calcium channels by a-conotoxins contributes to relief of nerve injury-induced neuropathic pain

alpha-Conotoxins that are thought to act as antagonists of nicotinic acetylcholine receptors (nAChRs) containing alpha 3-subunits are efficacious in several preclinical models of chronic pain. Potent interactions of Vc1.1 with other targets have suggested that the pain-relieving actions of alpha-conotoxins might be mediated by either alpha 9 alpha 10 nAChRs or a novel GABA(B) receptor-mediated inhibition of N-type calcium channels. Here we establish that three alpha-conotoxins, Vc1.1, AuIB and MII have distinct selectivity profiles for these three potential targets. Their potencies after intramuscular administration were then determined for reversal of allodynia produced by partial nerve ligation in rats. Vc1.1, which potently inhibits alpha 9 alpha 10 nAChRs and GABA(B)/Ca(2+) channels but weakly blocks alpha 3 beta 2 and alpha 3 beta 4 nAChRs, produced potent, long-lasting reversal of allodynia that were prevented by pre-treatment with the GABA(B) receptor antagonist, SCH50911. alpha-Conotoxin AuIB, a weak alpha 3 beta 4 nAChR antagonist, inhibited GABA(B)/Ca(2+) channels but did not act on alpha 9 alpha 10 nAChRs. AuIB also produced reversal of allodynia. These findings suggest that GABA(B) receptor-dependent inhibition of N-type Ca(2+) channels can mediate the sustained anti-allodynic actions of some alpha-conotoxins. However, MII, a potent alpha 3 beta 2 nAChR antagonist but inactive on alpha 9 alpha 10 and alpha 3 beta 4 nAChRs and GABA(B)/Ca(2+) channels, was demonstrated to have short-acting anti-allodynic action. This suggests that alpha 3 beta 2 nAChRs may also contribute to reversal of allodynia. Together, these findings suggest that inhibition of alpha 9 alpha 10 nAChR is neither necessary nor sufficient for relief of allodynia and establish that alpha-conotoxins selective for GABA(B) receptor-dependent inhibition of N-type Ca(2+) channels relieve allodynia, and could therefore be developed to manage chronic pain. (C) 2010 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved

Proceedings of patient reported outcome measure’s (PROMs) conference Sheffield 2016: Advances in patient reported outcomes research

Table of contents S1 Using computerized adaptive testing Tim Croudace S2 Well-being: what is it, how does it compare to health and what are the implications of using it to inform health policy John Brazier O1 “Am I going to get better?”—Using PROMs to inform patients about the likely benefit of surgery Nils Gutacker, Andrew Street O2 Identifying Patient Reported Outcome Measures for an electronic Personal Health Record Dan Robotham, Samantha Waterman, Diana Rose, Safarina Satkunanathan, Til Wykes O3 Examining the change process over time qualitatively: transformative learning and response shift Nasrin Nasr, Pamela Enderby O4 Developing a PROM to evaluate self-management in diabetes (HASMID): giving patients a voice Jill Carlton, Donna Rowen, Jackie Elliott, John Brazier, Katherine Stevens, Hasan Basarir, Alex Labeit O5 Development of the Primary Care Outcomes Questionnaire (PCOQ) Mairead Murphy, Sandra Hollinghurst, Chris Salisbury O6 Developing the PKEX score- a multimodal assessment tool for patients with shoulder problems Dominic Marley, James Wilson, Amy Barrat, Bibhas Roy O7 Applying multiple imputation to multi-item patient reported outcome measures: advantages and disadvantages of imputing at the item, sub-scale or score level Ines Rombach, Órlaith Burke, Crispin Jenkinson, Alastair Gray, Oliver Rivero-Arias O8 Integrating Patient Reported Outcome Measures (PROMs) into routine primary care for patients with multimorbidity: a feasibility study Ian Porter, Jaheeda Gangannagaripalli, Charlotte Bramwell, Jose M. Valderas O9 eRAPID: electronic self-report and management of adverse-events for pelvic radiotherapy (RT) patients Patricia Holch, Susan Davidson, Jacki Routledge, Ann Henry, Kevin Franks, Alex Gilbert, Kate Absolom & Galina Velikova O10 Patient reported outcomes (PROMs) based recommendation in clinical guidance for the management of chronic conditions in the United Kingdom Ian Porter, Jose M.Valderas O11 Cross-sectional and longitudinal parameter shifts in epidemiological data: measurement invariance and response shifts in cohort and survey data describing the UK’s Quality of Life Jan R. Boehnke O12 Patient-reported outcomes within health technology decision making: current status and implications for future policy Andrew Trigg, Ruth Howells O13 Can social care needs and well-being be explained by the EQ-5D? Analysis of Health Survey for England dataset Jeshika Singh, Subhash Pokhrel, Louise Longworth O14 Where patients and policy meet: exploring individual-level use of the Long-Term Conditions Questionnaire (LTCQ) Caroline Potter, Cheryl Hunter, Laura Kelly, Elizabeth Gibbons, Julian Forder, Angela Coulter, Ray Fitzpatrick, Michele Peter