Engineering NaV1.7 Inhibitory JzTx-V Peptides with a Potency and Basicity Profile Suitable for Antibody Conjugation To Enhance Pharmacokinetics.

Drug discovery research on new pain targets with human genetic validation, including the voltage-gated sodium channel NaV1.7, is being pursued to address the unmet medical need with respect to chronic pain and the rising opioid epidemic. As part of early research efforts on this front, we have previously developed NaV1.7 inhibitory peptide-antibody conjugates with tarantula venom-derived GpTx-1 toxin peptides with an extended half-life (80 h) in rodents but only moderate in vitro activity (hNaV1.7 IC50 = 250 nM) and without in vivo activity. We identified the more potent peptide JzTx-V from our natural peptide collection and improved its selectivity against other sodium channel isoforms through positional analogueing. Here we report utilization of the JzTx-V scaffold in a peptide-antibody conjugate and architectural variations in the linker, peptide loading, and antibody attachment site. We found conjugates with 100-fold improved in vitro potency relative to those of complementary GpTx-1 analogues, but pharmacokinetic and bioimaging analyses of these JzTx-V conjugates revealed a shorter than expected plasma half-life in vivo with accumulation in the liver. In an attempt to increase circulatory serum levels, we sought the reduction of the net +6 charge of the JzTx-V scaffold while retaining a desirable NaV in vitro activity profile. The conjugate of a JzTx-V peptide analogue with a +2 formal charge maintained NaV1.7 potency with 18-fold improved plasma exposure in rodents. Balancing the loss of peptide and conjugate potency associated with the reduction of net charge necessary for improved target exposure resulted in a compound with moderate activity in a NaV1.7-dependent pharmacodynamic model but requires further optimization to identify a conjugate that can fully engage NaV1.7 in vivo.

Extent of Playing-Related Musculoskeletal Problems in the Irish Traditional Music Community: A Survey.

BACKGROUND: The literature related to playing-related musculoskeletal disorders (PRMDs) primarily includes classical musicians and instrument-specific studies. Previous work by our team identified that PRMDs are an issue for Irish traditional fiddle players; however, the extent of the problem was not known. OBJECTIVE: To identify the type and extent of PRMDs in the Irish traditional music population, specifically fiddle players. METHODS: A questionnaire was developed and administered to faculty and students related to all Irish traditional music courses in all higher education institutions in Ireland. RESULTS: Seven institutions were included. The response rate was 77.5% (n=79 of 102 possible respondents). A fifth of respondents never had a PRMD, 36.7% (n=29) currently had a PRMD, and 34.2% (n=27) had a previous experience of a PRMD. The main symptoms were pain (62%, n=49), stiffness (41.8%, n=33), and tingling (35.4%, n=28). There was a positive association between the development of PRMDs and increased hours of play (p=0.017). CONCLUSIONS: PRMDs are a problem for Irish traditional fiddle players, especially during times of intense playing such as festivals.

Engineering Antibody Reactivity for Efficient Derivatization to Generate NaV1.7 Inhibitory GpTx-1 Peptide-Antibody Conjugates.

The voltage-gated sodium channel NaV1.7 is a genetically validated pain target under investigation for the development of analgesics. A therapeutic with a less frequent dosing regimen would be of value for treating chronic pain; however functional NaV1.7 targeting antibodies are not known. In this report, we describe NaV1.7 inhibitory peptide-antibody conjugates as an alternate construct for potential prolonged channel blockade through chemical derivatization of engineered antibodies. We previously identified NaV1.7 inhibitory peptide GpTx-1 from tarantula venom and optimized its potency and selectivity. Tethering GpTx-1 peptides to antibodies bifunctionally couples FcRn-based antibody recycling attributes to the NaV1.7 targeting function of the peptide warhead. Herein, we conjugated a GpTx-1 peptide to specific engineered cysteines in a carrier anti-2,4-dinitrophenol monoclonal antibody using polyethylene glycol linkers. The reactivity of 13 potential cysteine conjugation sites in the antibody scaffold was tuned using a model alkylating agent. Subsequent reactions with the peptide identified cysteine locations with the highest conversion to desired conjugates, which blocked NaV1.7 currents in whole cell electrophysiology. Variations in attachment site, linker, and peptide loading established design parameters for potency optimization. Antibody conjugation led to in vivo half-life extension by 130-fold relative to a nonconjugated GpTx-1 peptide and differential biodistribution to nerve fibers in wild-type but not NaV1.7 knockout mice. This study describes the optimization and application of antibody derivatization technology to functionally inhibit NaV1.7 in engineered and neuronal cells.

Perceptions of Playing-Related Musculoskeletal Disorders (PRMDs) in Irish traditional musicians: a focus group study.

BACKGROUND: Playing-related musculoskeletal disorders (PRMDs) are common in musicians and interfere with the ability to play an instrument at the accustomed level. There is limited research into injuries affecting folk musicians. OBJECTIVE: To explore the Irish traditional musicians' experience of PRMDs. METHODS: Focus group interviews were conducted in 2011 and 2012, in two venues in Ireland. Data were recorded and transcribed verbatim. Data collection ended when no new findings emerged from the analysis of interviews. The inclusion criteria were: males or females aged 18 and above, and who taught or played Irish traditional music on any instrument. The data were analysed using the interpretative phenomenological method. RESULTS: All participants (n=22) believed there was a link between playing music and musculoskeletal problems. The main body areas affected were the back, shoulders, arms and hands. The main theme that emerged was: 'PRMDs are an integral part of being a traditional musician', and that the musical experience was generally prioritised over the health of the musician. There were sub-themes of 'fear' and 'stresses that contributed to PRMDs'. CONCLUSIONS: PRMDs are an occupational hazard for Irish musicians. There is an awareness of PRMDs, but changes (technique, environment) may threaten identity.

Practicing safe trad: why existing approaches to playing-related musculoskeletal disorders may not help the Irish traditional music community.

Playing-related musculoskeletal disorders (PRMDs) as they affect the Irish traditional music community is a topic which, to date, has received scant attention. This paper draws on data generated through a series of four focus group interview studies conducted at the Universities of Ulster and Limerick and involving 22 musicians. Specifically, this paper looks at the wider issue of identity within the Irish traditional music community and at how the complexities inherent in this have, perhaps, affected musicians in recognizing, relating to, and dealing with PRMDs. Whether or not the injuries affecting Irish traditional musicians are similar to or different from what other musicians experience, what this study shows is that the sense of self and discrete identity among the Irish traditional music community is so very strong that merely a "one size fits all" approach to addressing these issues is not likely to yield positive results. Health professionals therefore need to be sensitive to such factors when considering their management of PRMDs and to develop approaches along with the traditional music community that are cognisant of their identity as well as their needs.

Aspects of social cognition in anorexia nervosa: affective and cognitive theory of mind.

Although social functioning is clearly impaired in anorexia nervosa (AN), there has been limited empirical assessment of this domain in this illness. This study assesses social cognition in AN by examining performance on two 'theory of mind' (ToM) tasks; Baron-Cohen's "Reading the mind in the Eyes" task (RME) and Happé's cartoon task. These tasks probe affective and cognitive ToM, respectively. Forty-four female participants were recruited (AN N=22; healthy controls N=22) and completed both tasks, with concurrent clinical and intellectual functioning assessment. Compared with healthy controls, AN performed significantly worse on both the RME and the Cartoon task (both conditions). The mental state condition did not facilitate performance in the AN group, as it did in the healthy controls. The findings broadly replicate limited previous work [Tchanturia, K., Happé, F., Godley, J., Bara-Carill, N., Treasure, J., Schmidt, U., 2004. Theory of mind in AN. European Eating Disorders Review 12, 361-366] but in addition demonstrate abnormalities on a task requiring affective ToM interpretation. More detailed information about the components of ToM and the ToM difficulties demonstrated in AN sufferers may inform our understanding of the disorder as well as future social-cognitive based treatments.