Towards the Targeted Protein Degradation of PRMT1.

Targeting the protein arginine methyltransferase 1 (PRMT1) has emerged as a promising therapeutic strategy in cancer treatment. The phase 1 clinical trial for GSK3368715, the first PRMT1 inhibitor to enter the clinic, was terminated early due to a lack of clinical efficacy, extensive treatment-emergent effects, and dose-limiting toxicities. The incidence of the latter two events may be associated with inhibition-driven pharmacology as a high and sustained concentration of inhibitor is required for therapeutic effect. The degradation of PRMT1 using a proteolysis targeting chimera (PROTAC) may be superior to inhibition as proceeds via event-driven pharmacology where a PROTAC acts catalytically at a low dose. PROTACs containing the same pharmacophore as GSK3368715, combined with a motif that recruits the VHL or CRBN E3-ligase, were synthesised. Suitable cell permeability and target engagement were shown for selected candidates by the detection of downstream effects of PRMT1 inhibition and by a NanoBRET assay for E3-ligase binding, however the candidates did not induce PRMT1 degradation. This paper is the first reported investigation of PRMT1 for targeted protein degradation and provides hypotheses and insights to assist the design of PROTACs for PRMT1 and other novel target proteins.

Perceptual consequences of online group speech treatment for individuals with Parkinson's disease: A pilot study case series.

PURPOSE: We examined perceptual changes in the domains of ease of understanding, naturalness, and speech severity, as well as changes in self-perceptions of voice disability, following an online group speech treatment program for people with Parkinson's disease (PD) conducted during the COVID-19 pandemic. METHOD: Seven speakers with hypokinetic dysarthria associated with PD participated in a university and community-based online group speech program for 10 weeks. Speech recordings occurred remotely 1 week before and 1 week after the online program. Thirty naïve listeners rated ease of understanding, naturalness, and speech severity based on the speech recordings. Speakers' self-perceptions of voice disability were also obtained at both time points. RESULT: Individual analysis of the speech data showed that for most speakers with dysarthria, ease of understanding and perceptions of severity were rated the same or better pre- to post-treatment. Naturalness, however, was only perceived to be the same or better post-treatment in three out of seven speakers. Over half of the speakers reported improvements in their self-perception of voice disability. CONCLUSION: This pilot study highlighted the individual variability among speakers with dysarthria and the potential of online group speech treatment to maintain and/or improve speech function in this population.

¿Notas La Diferencia? [Do You Hear the Difference?]: Perceptual Consequences of Intensive Voice Treatment in Spanish Speakers With Parkinson's Disease.

PURPOSE: The primary objective of this study was to explore the effects of intensive voice-focused treatment on speech parameters in Spanish speakers with dysarthria associated with Parkinson's disease (PD) as perceived by naïve listeners. METHOD: Fifteen Spanish speakers with dysarthria associated with PD received the Lee Silverman Voice Treatment (LSVT LOUD) for a month. Voice and speech recordings were conducted pretreatment, posttreatment, and at a 1-month follow-up. Thirty naïve adult listeners rated the perceptual dimensions of ease of understanding (EoU), resonance, articulatory precision, prosody, and voice quality from sentences extracted from an emotional monologue on a visual analogue scale. RESULTS: EoU, resonance, articulatory precision, and voice quality significantly improved pre- to posttreatment, but gains were not maintained at follow-up. Speech severity was a significant source of variance in mean listener response for all perceptual dimensions, although the interaction between speech severity and time was only significant for resonance and voice quality. CONCLUSIONS: LSVT LOUD may be beneficial to improve perceptual speech domains affected by PD in Spanish speakers with dysarthria. Its impact on the different speech subsystems may reflect a universal distribution of effects when directly targeting the glottal source. Language-specific contributions of each perceptual domain to speech intelligibility should be explored in further research to determine linguistically sensitive treatment targets.

Ketamine produces no detectable long-term positive or negative effects on cognitive flexibility or reinforcement learning of male rats.

RATIONALE: Patients with major depressive disorder (MDD) often experience abnormalities in behavioral adaptation following environmental changes (i.e., cognitive flexibility) and tend to undervalue positive outcomes but overvalue negative outcomes. The probabilistic reversal learning task (PRL) is used to study these deficits across species and to explore drugs that may have therapeutic value. Selective serotonin-reuptake inhibitors (SSRIs) have limited effectiveness in treating MDD and produce inconsistent effects in non-human versions of the PRL. As such, ketamine, a novel and potentially rapid-acting therapeutic, has begun to be examined using the PRL. Two previous studies examining the effects of ketamine in the PRL have shown conflicting results and only examined short-term effects of ketamine. OBJECTIVE: This experiment examined PRL performance across a 2-week period following a single exposure to a ketamine dose that varied across groups. METHODS: After five sessions of PRL training, groups of rats received an injection of either 0, 10, 20 or 30 mg/kg ketamine. One-hour post-injection, rats engaged in the PRL, and subsequently sessions continued daily for 2 weeks. Traditional behavioral and computational reinforcement learning-derived measures were examined. RESULTS: Results showed that ketamine had acute effects 1-h post-injection, including a significant decrease in the value of the punishment learning rate. Beyond 1 h, ketamine produced no detectable improvements nor decrements in performance across 2 weeks. CONCLUSION: Overall, the present results suggest that the range of ketamine doses examined do not have long-term positive or negative effects on cognitive flexibility or reward processing in healthy rats as measured by the PRL.

A recombinant approach for stapled peptide discovery yields inhibitors of the RAD51 recombinase.

Stapling is a macrocyclisation method that connects amino acid side chains of a peptide to improve its pharmacological properties. We describe an approach for stapled peptide preparation and biochemical evaluation that combines recombinant expression of fusion constructs of target peptides and cysteine-reactive divinyl-heteroaryl chemistry as an alternative to solid-phase synthesis. We then employ this workflow to prepare and evaluate BRC-repeat-derived inhibitors of the RAD51 recombinase, showing that a diverse range of secondary structure elements in the BRC repeat can be stapled without compromising binding and function. Using X-ray crystallography, we elucidate the atomic-level features of the staple moieties. We then demonstrate that BRC-repeat-derived stapled peptides can disrupt RAD51 function in cells following ionising radiation treatment.

Disulfide re-bridging reagents for single-payload antibody-drug conjugates.

Numerous antibody-drug conjugate (ADC) linker technologies exist for the synthesis of ADCs with drug-to-antibody ratios (DARs) being an even integer (typically 2, 4 or 8). However, ADCs with odd-integer DARs are significantly harder to synthesise. Here, we report the synthesis of ADCs loaded with a single warhead, using TetraDVP linkers which simultaneously re-bridge all four interchain disulfides of an IgG1 antibody.

Peroxide-cleavable linkers for antibody-drug conjugates.

Antibody-drug conjugates containing peroxide-cleavable arylboronic acid linkers are described, which target the high levels of reactive oxygen species (ROS) in cancer. The arylboronic acid linkers rapidly release a payload in the presence of hydrogen peroxide, but remain stable in plasma. Anti-HER2 and PD-L1 peroxide-cleavable ADCs exhibited potent cytotoxicity in vitro.

Acoustic Predictors of Ease of Understanding in Spanish Speakers With Dysarthria Associated With Parkinson's Disease.

PURPOSE: The purpose of this study was to examine selected baseline acoustic features of hypokinetic dysarthria in Spanish speakers with Parkinson's disease (PD) and identify potential acoustic predictors of ease of understanding in Spanish. METHOD: Seventeen Spanish-speaking individuals with mild-to-moderate hypokinetic dysarthria secondary to PD and eight healthy controls were recorded reading a translation of the Rainbow Passage. Acoustic measures of vowel space area, as indicated by the formant centralization ratio (FCR), envelope modulation spectra (EMS), and articulation rate were derived from the speech samples. Additionally, 15 healthy adults rated ease of understanding of the recordings on a visual analogue scale. A multiple linear regression model was implemented to investigate the predictive value of the selected acoustic parameters on ease of understanding. RESULTS: Listeners' ease of understanding was significantly lower for speakers with dysarthria than for healthy controls. The FCR, EMS from the first 10 s of the reading passage, and the difference in EMS between the end and the beginning sections of the passage differed significantly between the two groups of speakers. Findings indicated that 67.7% of the variability in ease of understanding was explained by the predictive model, suggesting a moderately strong relationship between the acoustic and perceptual domains. CONCLUSIONS: Measures of envelope modulation spectra were found to be highly significant model predictors of ease of understanding of Spanish-speaking individuals with hypokinetic dysarthria associated with PD. Articulation rate was also found to be important (albeit to a lesser degree) in the predictive model. The formant centralization ratio should be further examined with a larger sample size and more severe dysarthria to determine its efficacy in predicting ease of understanding.

Exploring Jordanian emergency registered nurses' experiences of workplace violence: A phenomenological study.

BACKGROUND: Workplace violence against emergency nurses is an alarming hazard in Jordan, as it is globally. There is no prior research exploring the experiences of workplace violence against Jordanian emergency nurses. This study aimed to investigate Jordanian emergency registered nurses' lived experiences of workplace violence from their patients or relatives while working. METHOD: A descriptive phenomenological study was conducted using Colaizzi's data analysis method. Twelve emergency nurses participated in this study and were recruited via two Facebook groups using purposeful sampling. RESULTS: Four themes emerged from the analysis of violence in the emergency department revealed in this phenomenological study: (1) feeling overwhelmed that violence is so common, (2) ambivalent feelings toward patients and their families, (3) The feeling of inadequacy in handling violent situations, and (4) nurses' suffering. DISCUSSION: The findings of this study have practical implications for in-service workplace training programs and may be used to inform potential changes to policies and legislation designed to establish a safer emergency department environment for nurses, patients and their relatives/visitors. CONCLUSION: The findings can help policymakers, healthcare leaders, and managers better understand the consequences of workplace violence to advocate for and establish workplace violence prevention programs and strategies to support nursing staff who have experienced these events.

Automatic Assessment of Intelligibility in Noise in Parkinson Disease: Validation Study.

BACKGROUND: Most individuals with Parkinson disease (PD) experience a degradation in their speech intelligibility. Research on the use of automatic speech recognition (ASR) to assess intelligibility is still sparse, especially when trying to replicate communication challenges in real-life conditions (ie, noisy backgrounds). Developing technologies to automatically measure intelligibility in noise can ultimately assist patients in self-managing their voice changes due to the disease. OBJECTIVE: The goal of this study was to pilot-test and validate the use of a customized web-based app to assess speech intelligibility in noise in individuals with dysarthria associated with PD. METHODS: In total, 20 individuals with dysarthria associated with PD and 20 healthy controls (HCs) recorded a set of sentences using their phones. The Google Cloud ASR API was used to automatically transcribe the speakers' sentences. An algorithm was created to embed speakers' sentences in +6-dB signal-to-noise multitalker babble. Results from ASR performance were compared to those from 30 listeners who orthographically transcribed the same set of sentences. Data were reduced into a single event, defined as a success if the artificial intelligence (AI) system transcribed a random speaker or sentence as well or better than the average of 3 randomly chosen human listeners. These data were further analyzed by logistic regression to assess whether AI success differed by speaker group (HCs or speakers with dysarthria) or was affected by sentence length. A discriminant analysis was conducted on the human listener data and AI transcriber data independently to compare the ability of each data set to discriminate between HCs and speakers with dysarthria. RESULTS: The data analysis indicated a 0.8 probability (95% CI 0.65-0.91) that AI performance would be as good or better than the average human listener. AI transcriber success probability was not found to be dependent on speaker group. AI transcriber success was found to decrease with sentence length, losing an estimated 0.03 probability of transcribing as well as the average human listener for each word increase in sentence length. The AI transcriber data were found to offer the same discrimination of speakers into categories (HCs and speakers with dysarthria) as the human listener data. CONCLUSIONS: ASR has the potential to assess intelligibility in noise in speakers with dysarthria associated with PD. Our results hold promise for the use of AI with this clinical population, although a full range of speech severity needs to be evaluated in future work, as well as the effect of different speaking tasks on ASR.

Antibody dual-functionalisation enabled through a modular divinylpyrimidine disulfide rebridging strategy.

Herein we report the development of a methodology for the dual-functionalisation of IgG antibodies. This is accomplished through the combination of disulfide rebridging divinylpyrimidine technology, with bicyclononyne and methylcyclopropene handles to facilitate sequential SPAAC and IEDDA reactions. Advantageously, the strategy does not require metal catalysis and avoids the need for purification between functionalisation steps.

All-in-one disulfide bridging enables the generation of antibody conjugates with modular cargo loading.

Antibody-drug conjugates (ADCs) are valuable therapeutic entities which leverage the specificity of antibodies to selectively deliver cytotoxins to antigen-expressing targets such as cancer cells. However, current methods for their construction still suffer from a number of shortcomings. For instance, using a single modification technology to modulate the drug-to-antibody ratio (DAR) in integer increments while maintaining homogeneity and stability remains exceptionally challenging. Herein, we report a novel method for the generation of antibody conjugates with modular cargo loading from native antibodies. Our approach relies on a new class of disulfide rebridging linkers, which can react with eight cysteine residues, thereby effecting all-in-one bridging of all four interchain disulfides in an IgG1 antibody with a single linker molecule. Modification of the antibody with the linker in a 1 : 1 ratio enabled the modulation of cargo loading in a quick and selective manner through derivatization of the linker with varying numbers of payload attachment handles to allow for attachment of either 1, 2, 3 or 4 payloads (fluorescent dyes or cytotoxins). Assessment of the biological activity of these conjugates demonstrated their exceptional stability in human plasma and utility for cell-selective cytotoxin delivery or imaging/diagnostic applications.

Predictors of older adults' chronic pain in the context of opioid adverse drug events.

BACKGROUND: Factors predictive of chronic pain in older adults could help focus prevention and treatment efforts for those most at risk of chronic pain. PURPOSE: The objective of the study was to describe demographic and pain self-management factors predictive of chronic pain in the context of opioid adverse drug events (ADEs) reported for a cohort of older adults within the same year. METHOD: The design was a post hoc analysis of 9,095 cases aged 65 years and older from the 2019 National Health Interview Survey that reported chronic pain and 380 cases aged 65 years and older with opioid adverse events reported to the Food and Drug Administration Adverse Event Reporting System (FAERS) during the second quarter of 2019. Logistic regression predicted chronic pain. RESULTS: Less than a baccalaureate education increased the odds of chronic pain by 28.0% while lower income minimally increased the odds. Male gender increased the odds of chronic pain by 12.0%. Increased age minimally increased the odds for chronic pain. Use of opioids, other pain treatments, complementary treatments, and antidepressants were all associated with increased odds of chronic pain. FAERS opioid ADEs ranged from pruritus to death, with death identified in 16 (4.2%) cases. Misuse, abuse, or dependence was documented in 1.8% of cases. CONCLUSIONS AND IMPLICATIONS: Less-educated older adults may be particularly at risk of chronic pain and should be routinely assessed and prescribed safe and efficacious pain self-management as needed. Some men may need additional support to use pain treatments.

Divinylpyrimidine reagents generate antibody-drug conjugates with excellent in vivo efficacy and tolerability.

The development of divinylpyrimidine (DVP) reagents for the synthesis of antibody-drug conjugates (ADCs) with in vivo efficacy and tolerability is reported. Detailed structural characterisation of the synthesised ADCs was first conducted followed by in vitro and in vivo evaluation of the ADCs' ability to safely and selectively eradicate target-positive tumours.

Rapid and robust cysteine bioconjugation with vinylheteroarenes.

Methods for residue-selective and stable modification of canonical amino acids enable the installation of distinct functionality which can aid in the interrogation of biological processes or the generation of new therapeutic modalities. Herein, we report an extensive investigation of reactivity and stability profiles for a series of vinylheteroarene motifs. Studies on small molecule and protein substrates identified an optimum vinylheteroarene scaffold for selective cysteine modification. Utilisation of this lead linker to modify a number of protein substrates with various functionalities, including the synthesis of a homogeneous, stable and biologically active antibody-drug conjugate (ADC) was then achieved. The reagent was also efficient in labelling proteome-wide cysteines in cell lysates. The efficiency and selectivity of these reagents as well as the stability of the products makes them suitable for the generation of biotherapeutics or studies in chemical biology.

A dual-enzyme cleavable linker for antibody-drug conjugates.

A novel enzyme cleavable linker for antibody-drug conjugates is reported. The 3-O-sulfo-ß-galactose linker is cleaved sequentially by two lysosomal enzymes - arylsulfatase A and ß-galactosidase - to release the payload in targeted cells. An α-HER2 antibody-drug conjugate synthesised using this highly hydrophilic dual-cleavable linker exhibited excellent cytotoxicity and selectivity.

Site-selective modification strategies in antibody-drug conjugates.

Antibody-drug conjugates (ADCs) harness the highly specific targeting capabilities of an antibody to deliver a cytotoxic payload to specific cell types. They have garnered widespread interest in drug discovery, particularly in oncology, as discrimination between healthy and malignant tissues or cells can be achieved. Nine ADCs have received approval from the US Food and Drug Administration and more than 80 others are currently undergoing clinical investigations for a range of solid tumours and haematological malignancies. Extensive research over the past decade has highlighted the critical nature of the linkage strategy adopted to attach the payload to the antibody. Whilst early generation ADCs were primarily synthesised as heterogeneous mixtures, these were found to have sub-optimal pharmacokinetics, stability, tolerability and/or efficacy. Efforts have now shifted towards generating homogeneous constructs with precise drug loading and predetermined, controlled sites of attachment. Homogeneous ADCs have repeatedly demonstrated superior overall pharmacological profiles compared to their heterogeneous counterparts. A wide range of methods have been developed in the pursuit of homogeneity, comprising chemical or enzymatic methods or a combination thereof to afford precise modification of specific amino acid or sugar residues. In this review, we discuss advances in chemical and enzymatic methods for site-specific antibody modification that result in the generation of homogeneous ADCs.

OXTR rs53576 Variation with Breast and Nipple Pain in Breastfeeding Women.

BACKGROUND: Thirty percent of women who seek professional breastfeeding support require assistance with ongoing breast and nipple pain and < 50% of women report resolution of their pain. It is unknown if there is a molecular risk for ongoing breast and nipple pain during breastfeeding. Aim -To evaluate associations among breast and nipple pain sensitivity and candidate pain sensitivity single-nucleotide polymorphisms [SNPs], (COMT rs6269, rs4633, rs4818, rs4680 and OXTR rs2254298, rs53576) in breastfeeding women. Design - A secondary analysis of a pilot randomized controlled trial of a pain self-management intervention conducted over 6 weeks postpartum. Setting and Participants - Sixty women were recruited from two hospital settings after birth. Methods - All participants underwent standardized mechanical somatosensory testing for an assessment of pain sensitivity and provided baseline buccal swabs for genetic analysis. At 1, 2, and 6 weeks postpartum, women self-reported breast and nipple pain severity using a visual analogue scale. Results - Women with the minor allele OXTR rs53576 reported 8.18-fold higher breast and nipple pain severity over time. For every 1-unit increase in Mechanical detection threshold and windup ratio, women reported 16.51-fold and 4.82-fold higher breast and nipple pain severity respectively. Six women with the OXTR rs2254298 minor allele reported allodynia. Conclusion - The presence of OXTR alleles in women with enhanced pain sensitivity suggests a phenotype of genetic risk for ongoing breast and nipple with potential for pain-associated breastfeeding cessation. Somatosensory testing identified women who reported higher breast and nipple pain during the first weeks of breastfeeding.

Photocatalytic methods for amino acid modification.

Amino acid modification plays an important role across several fields, including synthetic organic chemistry, materials science, targeted drug delivery and the probing of biological function. Although a myriad of methods now exist for the modification of peptides or proteins, many of these target a handful of the most reactive proteinogenic amino acids. Photocatalysis has recently emerged as a mild approach for amino acid modification, generating a sizable toolbox of reactions capable of modifying almost all of the canonical amino acids. These reactions are characterised by their mild, physiologically compatible conditions, greatly enhancing their usefulness for amino acid modification. This review aims to introduce the field of photocatalytic amino acid modification and discusses the most recent advances.

Expeditious Total Synthesis of Hemiasterlin through a Convergent Multicomponent Strategy and Its Use in Targeted Cancer Therapeutics.

Hemiasterlin is an antimitotic marine natural product with reported sub-nanomolar potency against several cancer cell lines. Herein, we describe an expeditious total synthesis of hemiasterlin featuring a four-component Ugi reaction (Ugi-4CR) as the key step. The convergent synthetic strategy enabled rapid access to taltobulin (HTI-286), a similarly potent synthetic analogue. This short synthetic sequence enabled investigation of both hemiasterlin and taltobulin as cytotoxic payloads in antibody-drug conjugates (ADCs). These novel ADCs displayed sub-nanomolar cytotoxicity against HER2-expressing cancer cells, while showing no activity against antigen-negative cells. This study demonstrates an improved synthetic route to a highly valuable natural product, facilitating further investigation of hemiasterlin and its analogues as potential payloads in targeted therapeutics.