Search

GPCRs are the most successful pharmaceutical targets in history. Nevertheless, the pharmacology of many GPCRs remains inaccessible as their endogenous or exogenous modulators have not been discovered. Tools that explore the physiological functions and pharmacological potential of these 'orphan' GPCRs, whether they are endogenous and/or surrogate ligands, are therefore of paramount importance. Rates of receptor deorphanization determined by traditional reverse pharmacology methods have slowed, indicating a need for the development of more sophisticated and efficient ligand screening approaches. Here, we discuss the use of structure-based ligand discovery approaches to identify small molecule modulators for exploring the function of orphan GPCRs. These studies have been buoyed by the growing number of GPCR crystal structures solved in the past decade, providing a broad range of template structures for homology modelling of orphans. This review discusses the methods used to establish the appropriate signalling assays to test orphan receptor activity and provides current examples of structure-based methods used to identify ligands of orphan GPCRs. Linked Articles This article is part of a themed section on Molecular Pharmacology of G Protein-Coupled Receptors. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v173.20/issuetoc.

Children are at increased risk of dehydration(1–3), which can adversely impact cognition and mood(4–6). Many children begin their school day dehydrated and fail to replenish fluids adequately throughout the day(7–11), however, these findings have not been confirmed using objective measures of hydration(12,13). This study aimed to confirm hydration status of primary school-aged children across the school day using objective hydration assessments and to examine if changes in hydration are associated with cognition and mood. Thirty children (mean age 9.4 ± 0.5 years old, stature 1.4 ± 0.5m, body mass 36.5 ± 4.2kg, and body mass index 18.9 ± 1.7 kg/m2) were recruited from a local primary school. Food and fluid intake were tracked via nutritional analysis of photographs. Urine osmolality (Uosm), serum osmolality (Sosm), urine specific gravity (USG) and self-reported urine colour (Ucol) were assessed at first void (Uosm only) or the start (9:00) and end (16:00) of the school day. Children's self-reported mood were obtained via Visual Analogue Scales(100mm) (9:00, 10:30, 13:30, 16:00). Children completed cognitive assessments using the Computerised Mental Performance Assessment System (15:3016:00). Mean total water intake was 759.9 ± 240.7 mL. Children consumed more fluid at mealtimes than from water bottle (Mean Difference (MD) 154.3mL, t(29) = -5.763, p<0.001). From the start to the end of the day, significant increases in Sosm (MD 3.3mOsm/kg, t(21) = 4.011, p = 0.002), USG (MD 0.0066, t(29) = 8.514, p = 0.005) and Ucol (MD 1.2, t(26) = 15.558, p = <0.001), indicated reduced hydration. The prevalence of dehydration (Sosm >290mOsm/kg USG >1.030) increased from the start (17%) to the end of school (40%). A series of ANOVAs from the start to the end of the day showed feelings of boredom, hunger, tiredness, and thirst increased, and focus, and happiness decreased (p's <0.05). Hydration measures were significantly associated with long term memory (LTM) (changes in Sosm, r = 0.437, p = 0.042) and working memory (WM) (changes in Sosm r = 0.462, p = 0.031, and USG, r = 0.403, p = 0.033). Children were less hydrated at the end of the school day suggesting inadequate fluid replacement during the school hours. Changes in hydration status across the school day were associated with subjective mood states. Furthermore, a decrease in hydration resulted in decreased performance in the memory tasks which could potentially hold implications on school performance. Children in this study had access to water throughout the day, however, most fluids were consumed at breakfast and lunch, suggesting interventions promoting sustained drinking throughout the day are required. For example, measures could be taken to educate parents and school staff on the importance of adequate hydration, and the need to remind children to drink throughout the day. For this to be effective, action needs to be taken across lesson time, meals, and break times. [ABSTRACT FROM AUTHOR]

Abstract Background This study examined the effect of carbohydrate and whey protein supplements on recovery of neuromuscular function after prolonged load carriage. Methods Ten male participants (body mass: 81.5 ± 10.5 kg, age: 28 ± 9 years, O2max: 55.0 ± 5.5 ml·kg-1·min-1) completed three treadmill walking tests (2 hr, 6.5 km·h-1), carrying a 25 kg backpack consuming 500 ml of either: (1) Placebo (flavoured water) [PLA], (2) 6.4% Carbohydrate Solution [CHO] or (3) 7.0% Whey Protein Solution [PRO]. For three days after load carriage, participants consumed two 500 ml supplement boluses. Muscle performance was measured before and at 0, 24, 48 and 72 h after load carriage, during voluntary and electrically stimulated contractions. Results Isometric knee extension force decreased immediately after load carriage with no difference between conditions. During recovery, isometric force returned to pre-exercise values at 48 h for CHO and PRO but at 72 h for PLA. Voluntary activation decreased immediately after load carriage and returned to pre-exercise values at 24 h in all conditions (P = 0.086). During recovery, there were no differences between conditions for the change in isokinetic peak torque. Following reductions immediately after load carriage, knee extensor and flexor peak torque (60°·s-1) recovered to pre-exercise values at 72 h. Trunk extensor and flexor peak torque (15°·s-1) recovered to pre-exercise values at 24 h (P = 0.091) and 48 h (P = 0.177), respectively. Conclusion Recovery of neuromuscular function after prolonged load carriage is improved with either carbohydrate or whey protein supplementation for isometric contractions but not for isokinetic contractions.

Purpose: Exertional heat stress can induce systemic endotoxin exposure and a proinflammatory cascade, likely impairing thermoregulation. Cannabidiol (CBD) is protective in preclinical models of tissue ischemia and inflammation. Therefore, this study examined the effects of CBD ingestion on exercise-induced thermoregulatory and inflammatory responses., Methods: In a randomized, double-blinded study, 13 active males (age 25 ± 5 yr; peak oxygen uptake (V̇O 2peak ) 50.4 ± 3.2 mL·kg -1 ·min -1 ) ingested 298 mg CBD or placebo 105 min before 1 h treadmill exercise (60%-65% V̇O 2peak ) in 32°C and 50% relative humidity. Core temperature, skin temperature, heart rate, subjective outcomes, and sweat loss were assessed during/after exercise. Plasma osmolality, plasma volume changes, and plasma markers of intestinal damage (I-FABP), monocyte activation (CD14), and inflammatory cytokine responses (IL-6, IL-8, and TNF-α) were assessed at baseline, pre-exercise, and 20 and 90 min post-exercise., Results: Core temperature (∆ 1.69°C ± 0.48°C (CBD) and 1.79°C ± 0.53°C (Placebo)) and I-FABP increased during exercise, with no differences between conditions ( P > 0.050). Mean (95% confidence interval) CD14 was 1776 (463 to 3090) pg·mL -1 greater 90 min post-exercise in placebo ( P = 0.049). Median (interquartile range) peak IL-6 concentration was -0.8 (-1.1 to -0.3) pg·mL -1 less in CBD ( P = 0.050), whereas the between-condition difference in IL-6 area under curve was -113 (-172 to 27) (pg·mL -1 )·270 min ( P = 0.054)., Conclusions: CBD did not affect thermoregulation during exertional heat stress but appeared to elicit minor immunosuppressive effects, reducing CD14 and IL-6 responses, warranting investigation in humans under more severe heat strain and other proinflammatory scenarios., (Copyright © 2024 by the American College of Sports Medicine.)

This study compared oxygen consumption and substrate oxidation while exercising in hot and temperate conditions in individuals with different physical activity status (i.e., inactive individuals vs. trained runners). 10 inactive individuals (IA: 26 ± 6 y; 79.1 ± 14.1 kg; 40.7 ± 5.1 ml·kg -1 ·min -1 ) and 10 trained runners (TR: 25 ± 6 y; 69.5 ± 9.1 kg; 63.1 ± 5.1 ml·kg -1 ·min -1 ) completed two incremental exercise tests (4 min stages) until exhaustion in temperate (TEMP: 18.7 ± 0.1 °C; 43.2 ± 4.1% relative humidity) and hot (HOT: 34.4 ± 0.2 °C and 42.6 ± 1.6% relative humidity) conditions. Expired gas and blood lactate concentrations were measured at the end of each stage. Peak oxygen consumption similarly decreased in HOT compared to TEMP for IA and TR (-13.2 ± 4.5% vs. -15.2 ± 7%; p =0.571; ES=0.25). In HOT compared to TEMP, lipid oxidation, from 30 to 70% of V̇O 2peak , was reduced for both groups (IA: p =0.023, ES=0.43; TR: p <0.001, ES=0.72) while carbohydrate oxidation was increased for TR ( p =0.011; ES=0.45) but not for IA ( p =0.268; ES=0.21). Core temperature was different between conditions for TR (higher in HOT, p =0.017; ES=0.66) but not for IA ( p =0.901; ES=0.25). Despite reduced physiological capacities in IA, both populations demonstrated reductions in lipid utilisation and peak oxygen consumption in hot compared to temperate conditions. However, the increased carbohydrate oxidation in HOT for TR were not observed in IA, potentially explained by lower thermal strain.

Background and Aims: Lackluster results from recently completed gene therapy clinical trials of VEGF-A delivered by viral vectors have heightened the need to develop alternative delivery strategies. This study aims to demonstrate the pre-clinical efficacy and safety of extracellular vesicles (EVs) loaded with VEGF-A mRNA for the treatment of ischaemic vascular disease., Methods: After encapsulation of full-length VEGF-A mRNA into fibroblast-derived EVs via cellular nanoporation (CNP), collected VEGF-A EVs were delivered into mouse models of ischaemic injury. Target tissue delivery was verified by in situ analysis of protein and gene expression. Functional rescue was confirmed by in vivo imaging and histology. The safety of single and serial delivery was demonstrated using immune-based assays., Results: VEGF-A EVs were generated with high mRNA content using a CNP methodology. VEGF-A EV administration demonstrated expression of exogenous VEGF-A mRNA by in situ RNA hybridization and elevated protein expression by western blot, microscopy, and enzyme-linked immunosorbent assay. Mice treated with human VEGF-A EVs after femoral or coronary artery ligation exhibited heightened neovascularization in ischaemic tissues with increased arterial perfusion and improvement in left ventricular function, respectively. Serial delivery of VEGF-EVs in injured skin showed improved wound healing with repeat administration. Importantly, as compared with adeno-associated viral and lipid nanoparticle VEGF-A gene therapy modalities, murine VEGF-A EV delivery did not trigger innate or adaptive immune responses at the injection site or systemically., Conclusions: This study demonstrated that VEGF-A EV therapy offers efficient, dose-dependent VEGF-A protein formation with low immunogenicity, resulting in new vessel formation in murine models of ischaemic vascular disease., (© The Author(s) 2025. Published by Oxford University Press on behalf of the European Society of Cardiology. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Purpose of Program: Canada's growing prevalence of people with kidney failure receiving kidney replacement therapy has necessitated the expansion of dialysis programs. Although facility-based hemodialysis is the predominant dialysis modality in Canada, it is substantially costlier than home dialysis (peritoneal or home hemodialysis). Initiatives to increase the uptake of home dialysis typically consist of didactic and experiential education. We describe a novel local initiative, Home Sweet Home (HSH), where individuals with lived experience of home dialysis and kidney health professionals share their experience and knowledge with participants in a clinic setting that has been set up to represent a metaphorical home. The aim of this report is to describe our HSH program and to evaluate its acceptability and reach for future scale and spread. We also explored home dialysis uptake among program participants., Sources of Information: We collected feedback from attendees following each HSH event with anonymized surveys. We obtained clinical and demographic data and modality at follow-up from 2 linked databases, the Canadian Organ Replacement Register (CORR) and a regional clinical database, the Nephrology Information System (NIS)., Methods: Reach was evaluated according to modality (i.e., the proportion of participants who were non-dialysis dependent vs the proportion receiving facility-based maintenance hemodialysis) and the proportion living remotely (defined as greater than 200 km from the event). We examined acceptability as the proportion who were interested in a home therapy (either peritoneal dialysis, home hemodialysis, or both) after attending the event. Demographic data and survey data were summarized with counts and percentages. Free text from surveys was collated and summarized. Participants were followed from the time of program attendance until June 21, 2022 or death., Key Findings: A total of 291 participants attended HSH between 2015 and 2019. At the time of program attendance, 70% of participants had chronic kidney disease (CKD) not requiring dialysis (CKD G4-5ND) and 30% had CKD G5D on facility-based maintenance hemodialysis. Participants were primarily urban dwelling (ie, in Edmonton). After the event, 92% of participants indicated they were interested in a home dialysis modality. From the survey free text, participants commonly expressed that they valued the "first-hand information" and a "real life perspective" from HSH facilitators and the simulation helped to ease anxiety about home dialysis. Participants expressed a desire for longer HSH events with more opportunities to ask questions. At a median follow-up of 858 days (interquartile range = 353-1347), 18% of the cohort remained dialysis independent and 25% died. Of the remaining 167 participants, N = 41 (25%) were receiving a home dialysis modality (either peritoneal dialysis or home hemodialysis), N = 40 (24%) received a kidney transplant, and N = 86 (51%) were dialyzing with facility-based hemodialysis., Limitations: A more in-depth understanding of how the HSH program influenced decision-making for home dialysis could be attained from interviews and focus groups. No causal inferences can be made regarding the uptake of home therapies and HSH attendance. We did not have data on who received a home therapy prior to the last recorded modality at follow-up, which likely underestimated the use of home therapies., Implications: The HSH program was highly acceptable with 92% of participants reporting they were interested in a home modality. The reach of HSH could be improved by recruiting more individuals from facility-based hemodialysis and rural and remote locations., Competing Interests: The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article., (© The Author(s) 2025.)

Virion-mediated outbreaks are imminent and despite rapid responses, continue to cause adverse symptoms and death. Therefore, tunable, sensitive, high-throughput assays are needed to help diagnose future virion-mediated outbreaks. Herein, it is developed a tunable in situ assay to selectively enrich virions and extracellular vesicles (EVs) and simultaneously detect antigens and nucleic acids at a single-particle resolution. The Biochip Antigen and RNA Assay (BARA) enhanced sensitivities compared to quantitative reverse-transcription polymerase chain reaction (qRT-PCR), enabling the detection of virions in asymptomatic patients, genetic mutations in single virions, and enabling the continued long-term expression of viral RNA in the EV-enriched subpopulation in the plasma of patients with post-acute sequelae of the coronavirus disease of 2019 (COVID-19). BARA revealed highly accurate diagnoses of COVID-19 by simultaneously detecting the spike glycoprotein and nucleocapsid-encoding RNA in saliva and nasopharyngeal swab samples. Altogether, the single-particle detection of antigens and viral RNA provides a tunable framework for the diagnosis, monitoring, and mutation screening of current and future outbreaks., (© 2024 The Author(s). Advanced Healthcare Materials published by Wiley‐VCH GmbH.)

Connections between the mechanical properties of DNA and biological functions have been speculative due to the lack of methods to measure or predict DNA mechanics at scale. Recently, a proxy for DNA mechanics, cyclizability, was measured by loop-seq and enabled genome-scale investigation of DNA mechanics. Here, we use this dataset to build a computational model predicting bias-corrected intrinsic cyclizability, with near-perfect accuracy, solely based on DNA sequence. Further, the model predicts intrinsic bending direction in 3D space. Using this tool, we aimed to probe mechanical selection - that is, the evolutionary selection of DNA sequence based on its mechanical properties - in diverse circumstances. First, we found that the intrinsic bend direction of DNA sequences correlated with the observed bending in known protein-DNA complex structures, suggesting that many proteins co-evolved with their DNA partners to capture DNA in its intrinsically preferred bent conformation. We then applied our model to large-scale yeast population genetics data and showed that centromere DNA element II, whose consensus sequence is unknown, leaving its sequence-specific role unclear, is under mechanical selection to increase the stability of inner-kinetochore structure and to facilitate centromeric histone recruitment. Finally, in silico evolution under strong mechanical selection discovered hallucinated sequences with cyclizability values so extreme that they required experimental validation, yet, found in nature in the densely packed mitochondrial(mt) DNA of Namystynia karyoxenos , an ocean-dwelling protist with extreme mitochondrial gene fragmentation. The need to transmit an extraordinarily large amount of mtDNA, estimated to be > 600 Mb, in combination with the absence of mtDNA compaction proteins may have pushed mechanical selection to the extreme. Similarly extreme DNA mechanics are observed in bird microchromosomes, although the functional consequence is not yet clear. The discovery of eccentric DNA mechanics in unrelated unicellular and multicellular eukaryotes suggests that we can predict extreme natural biology which can arise through strong selection. Our methods offer a way to study the biological functions of DNA mechanics in any genome and to engineer DNA sequences with desired mechanical properties., Competing Interests: Competing interests The authors declare no competing interests.

Heterozygosity for loss-of-function alleles of the genes encoding the four subunits of succinate dehydrogenase (SDHA, SDHB, SDHC, SDHD), as well as the SDHAF2 assembly factor predispose affected individuals to pheochromocytoma and paraganglioma (PPGL), two rare neuroendocrine tumors that arise from neural crest-derived paraganglia. Tumorigenesis results from loss of the remaining functional SDHx gene copy, leading to a cell with no functional SDH and a defective tricarboxylic acid (TCA) cycle. It is believed that the subsequent accumulation of succinate competitively inhibits multiple dioxygenase enzymes that normally suppress hypoxic signaling and demethylate histones and DNA, ultimately leading to increased expression of genes involved in angiogenesis and cell proliferation. Why SDH loss is selectively tumorigenic in neuroendocrine cells remains poorly understood. In the absence of SDH-loss tumor-derived cell models, the cellular burden of SDH loss and succinate accumulation have been investigated through conditional knockouts of SDH subunits in pre-existing murine or human cell lines with varying degrees of clinical relevance. Here we characterize two available murine SDH-loss cell lines, immortalized adrenally-derived premature chromaffin cells vs. immortalized fibroblasts, at a level of detail beyond that currently reported in the literature and with the intention of laying the foundation for future investigations into adaptive pathways and vulnerabilities in SDH-loss cells. We report different mechanistic and phenotypic manifestations of SDH subunit loss in the presented cellular contexts. These findings highlight similarities and differences in the cellular response to SDH loss between the two cell models. We show that adrenally-derived cells display more severe morphological cellular and mitochondrial alterations, yet are unique in preserving residual Complex I function, perhaps allowing them to better tolerate SDH loss, thus making them a closer model to SDH-loss PPGL relative to fibroblasts.(281 words)., Competing Interests: Declarations. Competing interests: The authors declare no competing interests. Data deposition: RNA sequencing data have been deposited in the Gene Expression Omnibus (GEO) database as GSE263778., (© 2024. The Author(s).)

Purpose: 7 days L-citrulline supplementation has been reported to improve blood pressure, V . O 2 kinetics, gastrointestinal (GI) perfusion and endurance cycling performance through increasing arterial blood flow. In situations where blood volume is compromised (e.g., hyperthermia/hypohydration), L-citrulline may improve thermoregulation and exercise performance by redistributing blood flow to aid heat loss and/or muscle function. This study assessed 7 days L-citrulline supplementation on running performance in the heat, whilst mildly hypohydrated., Methods: 13 endurance runners (2 female, 31 ± 8 y, V . O 2 peak 60 ± 6 mL/kg/min) participated in a randomised crossover study with 7 days L-citrulline (CIT; 6 g/d) or placebo (maltodextrin powder; PLA) supplementation. Participants completed a 50 min running 'preload' at 65% V . O 2 peak (32 °C, 50% relative humidity) to induce hyperthermia and hypohydration before a 3 km running time trial (TT). Body mass and blood samples were collected at baseline, pre-preload, post-preload and post-TT, whilst core and skin temperature, heart rate and perceptual responses were collected periodically throughout., Results: TT performance was not different between trials (CIT 865 ± 142 s; PLA 892 ± 154 s; P = 0.437). Core and skin temperature and heart rate (P ≥ 0.270), hydration (sweat rate, plasma volume, osmolality) indices (P ≥ 0.216), GI damage (P ≥ 0.260) and perceptual responses (P ≥ 0.610) were not different between trials during the preload and TT., Conclusions: 7 days of L-citrulline supplementation had no effect on 3 km running performance in the heat or any effects on thermoregulation or GI damage in trained runners in a hypohydrated state., Competing Interests: Declarations. Conflict of interest: This is a summary of independent research funded by Loughborough University and carried out at the National Institute for Health and Care Research (NIHR) Leicester Biomedical Research Centre (BRC). The views expressed are those of the author(s) and not necessarily those of Loughborough University, the NIHR or the Department of Health and Social Care. M.P.F. is funded by the National Institute for Health Research (NIHR) Applied Research Collaboration East Midlands (ARC EM). S.J.B. has current/previous funding from KIRIN Central Research Institute, Fitoplancton Marino SL, Kaneka Medical Europe, Bio-gen Extracts and Herbalife Europe Ltd. In all cases, monies have been paid to S.J.B’s institution and not directly to SJB. S.A.M. has current/previous funding from Entrinsic Beverage Company LLP and Herbalife Europe Ltd and has received honorariums from Unilever PLC to present at conferences. L.J.J. has current/previous funding from Bunge Loders Croklaan B.V., Herbalife Europe Ltd, Bridge Farm Nurseries ltd., Entrinsic Beverage Company LLP, Decathlon SA, PepsiCo Inc. and Volac International, has performed consultancy for The British Horseracing Authority, Lucozade, Ribena Suntory and PepsiCo Inc., and has received conference fees from PepsiCo Inc. and Danone Nutricia. In all cases, monies have been paid to LJJ’s institution. LJJ is part of the National Institute for Health Research’s Leicester Biomedical Research Centre, which is a partnership between University Hospitals of Leicester NHS Trust, Loughborough University, and the University of Leicester., (© 2024. The Author(s).)

Exercise in warm environments increases thermal/cardiovascular strain and decreases gastrointestinal (GI) integrity and endurance performance. However, laboratory-based studies have provided little to/no facing airflow, potentially exacerbating these effects, particularly for cycling, where convective cooling may be a major contributor to thermal balance., Purpose: This study investigated the effect of cycling in a warm vs temperate environment with sufficient facing airflow on exogenous glucose use, performance, and GI responses., Methods: Ten trained male cyclists/triathletes (36 ± 6 y; 55 ± 6 mL/kg/min) completed V̇O2peak and familiarisation trials, and two experimental trials in 19 °C (TEMP) and 32 °C (WARM). Experimental trials involved 2 h cycling at ~50% Wpeak (preload) and an ~15 min time trial (TT) with fan-provided airflow covering the cyclist (preload: ~29 km/h, TT: ~35 km/h). A glucose drink containing [U-13C]-glucose was consumed every 20 min during the preload (72 g/h)., Results: Average 40-120 min (TEMP 0.56 ± 0.13 g/min; WARM 0.48 ± 0.12 g/min; 15%; P = 0.015) and peak (TEMP 0.79 ± 0.18 g/min; WARM 0.68 ± 0.14 g/min; 14%; P = 0.008) exogenous glucose oxidation were reduced in WARM. TT performance was 15% slower in WARM (TEMP 819 ± 47 s; WARM 961 ± 130 s; P = 0.002). GI temperature (P = 0.007), heart rate (P < 0.001), and RPE (P = 0.046) were greater during WARM. GI comfort (P = 0.659) and Intestinal Fatty Acid Binding Protein (IFABP) (P = 0.094) were not different between trials., Conclusions: These data demonstrate that ability to use glucose provided in drinks was impaired during prolonged cycling in WARM. WARM ambient conditions impaired laboratory-based cycling performance, even with facing airflow approximating outdoor conditions, likely via impairments of thermoregulatory, cardiovascular, and metabolic function., Competing Interests: Conflict of Interest and Funding Source: KMR is a doctoral researcher funded by Decathlon SE (Principal Investigator LJJ) and Loughborough University. LJJ is part of the National Institute for Health Research’s Leicester Biomedical Research Centre, which is a partnership between University Hospitals of Leicester NHS Trust, Loughborough University, and the University of Leicester. LJJ has current/previous funding from Entrinsic Beverage Company LLC, Entrinsic Bioscience LLC, Herbalife Europe Ltd, Bridge Farm Nurseries, Decathlon SE, PepsiCo Inc., Volac International; has performed consultancy for PepsiCo Inc. and Lucozade, Ribena Suntory; and has received conference fees from PepsiCo Inc. and Danone Nutricia. In all cases, monies have been paid to LJJs institution and not directly to LJJ. SAM has current/previous funding from Entrinsic Beverage Company LLP and Herbalife Europe Ltd. The authors declare no other conflict of interest., (Copyright © 2024 by the American College of Sports Medicine.)

Competing Interests: Declaration of interest statement No conflicts of interest.

Acetate, propionate, and butyrate are naturally-occurring short-chain fatty acids (SCFAs) derived from bacterial metabolism of dietary fibre and have been associated with numerous positive health outcomes. All three acids have been shown to offer unique physiological and metabolic effects and, therefore, could be targeted for co-ingestion as part of a nutritional/medicinal plan. However, a better understanding of the outcomes of supplementing in combination on circulating concentration profiles is necessary to confirm uptake efficacy. This study sought to investigate the acute circulating concentration profiles of acetate, propionate, and butyrate following oral supplementation. Three experimental trials were conducted including investigations to understand the impact of capsule coating on circulating concentration profiles, the effect of supplementation dose on uptake kinetics, and the outcome of a short, repeated, supplementation routine on circulating levels. Serum samples were analysed for SCFA content using a quantitative GC-MS assay. It was observed that an acid-resistant coated capsule caused a delayed and blunted blood concentration response, with the non-acid resistant trial displaying earlier and more intense peak serum concentrations. For dose comparison investigations, all SCFAs peaked within 60 min and returned to baseline concentrations by 120 min post-supplementation. A graded dose relationship was present for propionate and butyrate when considering the total circulating exposure across a 240 min monitoring period. In addition, a one-week, twice-daily, repeated supplementation protocol resulted in no changes in basal serum SCFA concentrations. Overall, these data indicate that acetate, propionate, and butyrate display relatively similar circulating concentration profiles following oral co-ingestion, adding knowledge to help inform supplementation strategies for future outcomes where acute elevation of circulating SCFAs is desired.

The A1 domain in Von Willebrand Factor (VWF) initiates coagulation through binding to platelet glycoprotein GPIbα receptors. Von Willebrand Disease (VWD)-Mutations in A1 that either impair (type 2M) or enhance (type 2B) platelet adhesion to VWF can locally destabilize and even misfold the domain. We leveraged misfolding in the gain-of-function type 2B VWD phenotype as a target, distinct from the normal conformation. Two nuclease-resistant 2'-fluoropyrimidine RNA aptamers were selected to discriminate normal A1 domains from a type 2B V1314D A1 variant in a glycosylated A1A2A3 tri-domain VWF-fragment. Two aptamers, W9 and V1, were isolated that selectively recognize, bind, and inhibit the A1-GPIbα interaction with WT A1A2A3 and V1314D A1A2A3, respectively. These aptamers were tested against their respective recombinant targets, plasma VWF, VWF concentrates, and patient plasma with the heterozygous type 2B VWD R1306W variant using clinical assays, surface plasmon resonance and inhibition assays of platelet adhesion to recombinant A1 and A1A2A3 domains under shear stress. The specificity of W9 and V1 aptamers confirms that pathological conformations of VWD Type 2B proteins are different from normal VWF. The availability of aptamers that distinguish normal plasma-derived VWF from VWD suggests potential applicability in clinical diagnosis of severe gain-of-function phenotypes., (© The Author(s) 2024. Published by Oxford University Press on behalf of NAR Molecular Medicine.)

There is an urgent need for agents that promote health and regeneration of cells and tissues, specifically to treat diseases of the aging nervous system. Age-associated nervous system degeneration and various diseases are driven by many different biochemical stresses, often making it difficult to target any one disease cause. Our laboratory has previously identified DNA aptamers with apparent regenerative properties in murine models of multiple sclerosis by selecting aptamers that bind oligodendrocyte membrane preparations. Here, we selected from vast libraries of molecules (∼10 14 unique DNAs) those with the ability to bind cultured human SH-SY5Y neuroblastoma cells as a neuronal model, followed by screening for aptamers capable of eliciting biological responses, with validation of binding in differentiated SH-SY5Y, human induced pluripotent stem cell (iPSC)-derived sensory neurons, and human embryonic stem cell (hESC)-derived cortical neurons. This demonstrates a proof-of-concept workflow to identify biologically active aptamers by cycles of cell selection., Competing Interests: L.S. is a scientific co-founder and consultant of Bluerock Therapeutics and DaCapo Brainscience., (© 2024 The Author(s).)

Background/objectives: Unmet oral health needs of residents in residential aged care facilities (RACFs) arise due to the unique challenges of assessing oral health statuses and maintaining oral healthcare in RACFs. This pilot study assessed the feasibility of using real-time teledentistry under the guidance of a dentist to train RACF staff to undertake an oral health assessment., Methods: An oral health assessment of residents was first conducted by RACF staff at two Queensland, Australia RACFs using the Oral Health Assessment Tool, with an intra-oral camera connected to a laptop, through videoconferencing, under the guidance of a dentist. A survey recorded the views of RACF staff on the acceptability of the teledentistry method. The quality of the images obtained through the camera was assessed by the dentist. Finally, cost-effectiveness was calculated between teledentistry and traditional face-to-face assessments., Results: Sixteen residents (mean age 79.3 ± 8.68 years) and eight staff (mean age 33.3 ± 6.16 years) participated in this study. Both RACF staff and residents found that the real-time teledentistry set-up was user-friendly, while the dentist rated the quality of the images as acceptable for diagnostic purposes. Real-time teledentistry was more cost-effective than bringing a dentist on-site, while taking the RACF residents to an off-site dental office for examination was the most expensive approach., Conclusions: Real-time teledentistry is feasible and cost-effective, and it is an acceptable alternative to a face-to-face clinical exam for oral health assessment in RACFs. This approach could be used in RACFs where wireless internet connectivity is available.

Purpose: Cow's milk is one of the most hydrating beverages, but many individuals choose not to consume dairy in their diet due to intolerance, allergy, or dietary preference. Milk is commonly replaced with plant-based beverages, including soya which has the most comparable protein content, but little is known about their hydration potential. This study compared fluid and electrolyte balance responses between a soya beverage and skimmed cow's milk., Methods: Ten healthy males [age 27 (6) y; body mass index 24.6 (2.3) kg/m 2 ] completed two randomised counterbalanced trials, involving consuming 1000 mL water from approximately isocaloric amounts of skimmed cow's milk (MILK) or a sweetened soya beverage (SOYA), in four aliquots over 30 min in a euhydrated fasted state. Volume, specific gravity, and electrolyte (sodium, potassium, chloride) concentrations were determined in total-void urine samples collected pre-/post-beverage ingestion, and hourly for 180 min thereafter. Hunger, thirst, nausea and stomach fullness were rated proximal to urine samples., Results: Total urine mass (MILK, 986 ± 254 g; SOYA, 950 ± 248 g; P = 0.435) and urine specific gravity (P = 0.156) did not differ between trials. Potassium balance was greater in SOYA 0-180 min post-beverage (P ≤ 0.013), whilst chloride balance was greater in MILK 0-120 min post-beverage (P ≤ 0.036). Sodium balance (P = 0.258), total electrolyte balance (P = 0.258), and subjective measures (P ≥ 0.139) were not different between trials., Conclusion: Replacing cow's milk with a soya beverage did not negatively impact fluid balance in healthy young males, making it a viable option for those who choose not to consume dairy in their diet., (© 2024. The Author(s).)

Introduction: Cannabidiol (CBD) is a nonintoxicating phytocannabinoid used in clinical treatments and sold widely in consumer products. CBD products may be designed for sublingual or oral delivery, but it is unclear whether either is advantageous for CBD absorption. This study compared CBD pharmacokinetics after providing CBD oil as sublingual drops and within orally ingested gelatin capsules, at a dose relevant to consumer products. Materials and Methods: Eight males completed three conditions in a participant-blinded, randomized crossover design. Participants received the following combinations of placebo and CBD-containing (69 mg/mL) hemp oil in capsules and as sublingual drops: placebo capsules/placebo drops ( Placebo ), CBD capsules/placebo drops ( CBD-Caps ), and placebo capsules/CBD drops ( CBD-Drops ). Blood samples, blood pressure, and subjective scales were obtained/completed hourly for 6 h and at 24 h. Discussion: Plasma CBD concentrations were not different between CBD-Caps and CBD-Drops (interaction effect p =0.76). Peak CBD concentration (28.0±15.6 vs. 24.0±22.2 ng/mL), time of peak CBD concentration (4±1 vs. 4±2 h), and area under the concentration curve (45.3±20.3 vs. 41.8±23.3 ng/mL·6 h) were not different between conditions ( p ≥0.25). Cardiometabolic outcomes (plasma glucose/triacylglycerol, heart rate, blood pressure), liver function (plasma alanine aminotransferase/aspartate aminotransferase), kidney function (plasma creatinine), and subjective feelings/symptoms were not different between conditions ( p ≥0.07). Conclusions: Plasma CBD profiles were comparable between CBD-Caps and CBD-Drops , suggesting that there were not meaningful differences in routes of CBD absorption between conditions. This implies that CBD oil delivered sublingually is swallowed before oral mucosal CBD absorption occurs, which may have implications for research design, CBD product design, and consumer product choice.

Heterobimetallic cages built from Pd and either octahedral Ru or square-planar Pt moieties and bridged by ligands with H bonding-accepting or -donating properties are reported. They showed stimulus-responsive dis- and reassembly, while guest binding was found to be dependent on the complementary properties of the guest to the host in terms of charge, size and H bonding properties.

Metallosupramolecular architectures formed from metal ions and bridging ligands are increasing in popularity due to their range of applications and ease of self-assembly. Many are able to readily change their shape and/or function in response to an external stimulus and have the ability to encapsulate guest molecules within their internal cavities. Ferrocenyl groups (Fc) have been incorporated previously within the bridging ligands of metallosupramolecular structures due to their ideal attributes brought about by the structural and rotational flexiblity of the two cyclopentadienyl (Cp) rings coordinated to the Fe(II) centre. However, the majority of these Fc-based structures contain symmetrically substituted Cp rings. We report the synthesis and characterisation of non-symmetrically functionalised Fc-based ligands incorporating both N , N ' and NHC-donor groups chosen for their differing coordination properties. Both substituents were designed to coordinate to a single metal centre with the dissimilar coordination properties of each donor group facilitating stimulus-induced dissociation/association of one of the substituents as an opening/closing mechanism. Preliminary investigations into the coordination of these Fc-based ligands to a [Ru(η 6 - p -cymene)] 2+ moiety indicated complexation through a mixture of either a bi- or tridentate fashion, as alluded by 1 H NMR spectroscopy and mass spectrometry. Density functional theory (DFT) calculations revealed the Fc-based ligands adopt a syn conformation driven by H-bonding and π-interactions between the two Cp substituents, which facilitate coordination of both donor groups towards the metal centre.

Natural prokaryotic gene repression systems often exploit DNA looping to increase the local concentration of gene repressor proteins at a regulated promoter via contributions from repressor proteins bound at distant sites. Using principles from the Escherichia coli lac operon we design analogous repression systems based on target sequence-programmable Transcription Activator-Like Effector dimer (TALED) proteins. Such engineered switches may be valuable for synthetic biology and therapeutic applications. Previous TALEDs with inducible non-covalent dimerization showed detectable, but limited, DNA loop-based repression due to the repressor protein dimerization equilibrium. Here, we show robust DNA loop-dependent bacterial promoter repression by covalent TALEDs and verify that DNA looping dramatically enhances promoter repression in E. coli. We characterize repression using a thermodynamic model that quantitates this favorable contribution of DNA looping. This analysis unequivocally and quantitatively demonstrates that optimized TALED proteins can drive loop-dependent promoter repression in E. coli comparable to the natural LacI repressor system. This work elucidates key design principles that set the stage for wide application of TALED-dependent DNA loop-based repression of target genes., (© The Author(s) 2024. Published by Oxford University Press on behalf of Nucleic Acids Research.)

A series of iridium pentamethylcyclopentadienyl (Cp*) complexes, [Cp*Ir(κ 2 - R L p / m )Cl], that contain the strongly coordinating bidentate ligands R L p / m were synthesized. The donor groups of the bidentate ligands were an N- amidate and either a para- pyridinylidene remote N -heterocyclic carbene ( R L p ) or a meta- pyridinylidene remote N -heterocyclic carbene ( R L m ). For each type of bidentate ligand, a set of iridium complexes was synthesized, which differed only according to the substituents ( R ) on the phenyl ring associated with the amidate group. The iridium complexes were all fully characterized and molecular structures were obtained by single-crystal X-ray diffraction studies for representative examples. The complexes were found to be good precatalysts in iso -propanol for the transfer hydrogenation of benzaldehyde to give benzyl alcohol. The catalytic activity correlated with the Hammett σ m/p parameters of the phenyl ring substituents, with more electron-donating substituents leading to increased catalytic activity. In all cases, the meta- pyridinylidene complexes, [Cp*Ir(κ 2 - R L m )Cl], performed better than the corresponding para analogues, [Cp*Ir(κ 2 - R L p )Cl].

Reduced skeletal muscle mass and oxidative capacity coexist in patients with pulmonary emphysema and are independently associated with higher mortality. If reduced cellular respiration contributes to muscle atrophy in that setting remains unknown. Using a mouse with genetically induced pulmonary emphysema that recapitulates muscle dysfunction, we found that reduced activity of succinate dehydrogenase (SDH) is a hallmark of its myopathic changes. We generated an inducible, muscle-specific SDH knockout mouse that demonstrates lower mitochondrial oxygen consumption, myofiber contractility, and exercise endurance. Respirometry analyses show that in vitro complex I respiration is unaffected by loss of SDH subunit C in muscle mitochondria, which is consistent with the pulmonary emphysema animal data. SDH knockout initially causes succinate accumulation associated with a down-regulated transcriptome but modest proteome effects. Muscle mass, myofiber type composition, and overall body mass constituents remain unaltered in the transgenic mice. Thus, while SDH regulates myofiber respiration in experimental pulmonary emphysema, it does not control muscle mass or other body constituents.