Determining the role of the human transient receptor potential ankyrin A (hTRPA1) ion channel in pain sensation

Lead Research Organisation: University of Oxford
Department Name: Interdisciplinary Bioscience DTP

Abstract

Chronic pain is a major health problem worldwide and is especially prevalent in ageing populations. Pain is a complex phenotype as a consequence of the multiple pathways involved in initiating and propagating the pain response. However, the molecular mechanisms of these pathways are largely unclear. Further, one of the longest standing mysteries in defence is how some chemicals, especially riot control agents, interact with the human nervous system to cause irritation (including pain sensation). Understanding the molecular mechanisms behind these responses will give a clearer insight into how to accelerate the development of novel pain-relieving drugs, and how to protect humans from irritant chemicals.
A major mechanism of pain initiation is thought to involve stimulation of the promiscuous ion channel hTRPA1. Work to identify novel treatments countering hTRPA1 stimulation is currently hindered by the lack of mechanistic information on how chemicals (and indeed other stimulants) induce channel activation. Given that hTRPA1 can be activated by multiple stimulants, there are likely many mechanisms underpinning channel activation. Mechanisms of activation by electrophilic compounds (e.g. CS tear gas) likely involve reactions with nucleophilic residues on hTRPA1 (cysteine/lysine); however, it is unclear which residues are susceptible to modification (and indeed whether all reactive irritants react at the same sites), and also how these modifications facilitate ion influx. The proposed project aims to address these issues by characterising the structures of hTRPA1 electrophile adducts and the mechanisms by which such reactions activate the channel, using chemical, biochemical and biological techniques.
Throughout the project, the student will receive extensive supervision and support from researchers in the Department of Chemistry in Oxford and at the Defence Science and Technology Laboratory (Dstl), based at Porton Down. In Oxford, the student will undertake synthesis and characterisation of known/potential hTRPA1 stimulants (small molecule electrophiles), as well as (bio)chemical and structural analyses of their reactions with nucleophilic amino acids (proof of principle studies) and recombinantly expressed hTRPA1. During this work, the student will receive training in a variety of synthetic chemistry, biochemical and spectroscopic techniques (e.g. nuclear magnetic resonance spectroscopy, mass spectrometry, infra-red spectroscopy, small molecule and protein X-ray crystallography, circular dichroism, differential scanning fluorimetry, isothermal titration calorimetry), and recombinant protein expression and purification. At Dstl, the student will assess the ability of their synthesised compounds to stimulate hTRPA1 in human cells using fluorescent-based and patch-clamping approaches, for which the student will receive training and supervision, as well as help with interpreting structure-activity data using appropriate software and statistical packages. It is expected that the student will spend at least 6 months of their studies at Dstl.

Publications


10 25 50

Studentship Projects

Project Reference Relationship Related To Start End Student Name
BB/M011224/1 01/10/2015 30/09/2023
1801761 Studentship BB/M011224/1 01/10/2016 30/09/2020 Benjamin Saward