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In the past few years there has been a growth in the use of nanoparticles for stabilizing lipid membranes that contain embedded proteins. These bionanoparticles provide a solution to the challenging problem of membrane protein isolation by maintaining a lipid bilayer essential to protein integrity and activity. We have previously described the use of an amphipathic polymer （poly（styrene-co-maleic add）, SMA） to produce discoidal nanoparticles with a lipid bilayer core containing the embedded protein. However the structure of the nanoparticle itself has not yet been determined. This leaves a major gap in understanding how the SMA stabilizes the encapsulated bilayer and how the bilayer relates physically and structurally to an unencapsulated lipid bilayer. In this paper we address this issue by describing the structure of the SMA lipid particle （SMALP） using data from small angle neutron scattering （SANS）, electron microscopy （EM）, attenuated total reflection Fourier transform infrared spectroscopy （ATR-FTIR）, differential scanning calorimetry （DSC） and nuclear magnetic resonance spectroscopy （NMR）. We show that the particle is disc shaped containing a polymer ＂bracelet＂ encircling the lipid bilayer. The structure and orientation of the individual components within the bilayer and polymer are determined showing that styrene moieties within SMA intercalate between the lipid acyl chains. The dimensions of the encapsulated bilayer are also determined and match those measured for a natural membrane. Taken together, the description of the structure of the SMALP forms the foundation for future development and applications of SMALPs in membrane protein production and analysis.

This protocol from Lee et al . describes a method for the extraction of membrane proteins in their native lipid environment using styrene maleic anhydride (SMA) co-polymer. The method is applicable to both prokaryotic and eukaryotic expression systems. Despite the great importance of membrane proteins, structural and functional studies of these proteins present major challenges. A significant hurdle is the extraction of the functional protein from its natural lipid membrane. Traditionally achieved with detergents, purification procedures can be costly and time consuming. A critical flaw with detergent approaches is the removal of the protein from the native lipid environment required to maintain functionally stable protein. This protocol describes the preparation of styrene maleic acid (SMA) co-polymer to extract membrane proteins from prokaryotic and eukaryotic expression systems. Successful isolation of membrane proteins into SMA lipid particles (SMALPs) allows the proteins to remain with native lipid, surrounded by SMA. We detail procedures for obtaining 25 g of SMA (4 d); explain the preparation of protein-containing SMALPs using membranes isolated from Escherichia coli (2 d) and control protein-free SMALPS using E. coli polar lipid extract (1–2 h); investigate SMALP protein purity by SDS–PAGE analysis and estimate protein concentration (4 h); and detail biophysical methods such as circular dichroism (CD) spectroscopy and sedimentation velocity analytical ultracentrifugation (svAUC) to undertake initial structural studies to characterize SMALPs (∼2 d). Together, these methods provide a practical tool kit for those wanting to use SMALPs to study membrane proteins.

Significance Certain oligomeric species generated during the self-assembly of specific proteins into ordered fibrillar aggregates are likely to be key players in the initiation and spreading of neurodegenerative diseases. We have purified stable toxic oligomeric species of α-synuclein and defined and minimized their degree of heterogeneity, which has allowed us to identify distinct subgroups of oligomers and determine their structural properties and three-dimensional molecular architectures. All the oligomeric subgroups possess approximately cylindrical architectures with marked similarities to amyloid fibrils, suggesting that these types of oligomers are kinetically trapped during protein self-assembly. The relative stabilities and inherent pathological roles of different amyloid oligomers are likely to result from the multiplicity of pathways of the misfolding process and the remarkably slow rates of structural conversions. We describe the isolation and detailed structural characterization of stable toxic oligomers of α-synuclein that have accumulated during the process of amyloid formation. Our approach has allowed us to identify distinct subgroups of oligomers and to probe their molecular architectures by using cryo-electron microscopy (cryoEM) image reconstruction techniques. Although the oligomers exist in a range of sizes, with different extents and nature of β-sheet content and exposed hydrophobicity, they all possess a hollow cylindrical architecture with similarities to certain types of amyloid fibril, suggesting that the accumulation of at least some forms of amyloid oligomers is likely to be a consequence of very slow rates of rearrangement of their β-sheet structures. Our findings reveal the inherent multiplicity of the process of protein misfolding and the key role the β-sheet geometry acquired in the early stages of the self-assembly process plays in dictating the kinetic stability and the pathological nature of individual oligomeric species.

G-protein coupled receptors (GPCRs) constitute the largest class of membrane proteins and are a major drug target. A serious obstacle to studying GPCR structure/function characteristics is the requirement to extract the receptors from their native environment in the plasma membrane, coupled with the inherent instability of GPCRs in the detergents required for their solubilization. In the present study, we report the first solubilization and purification of a functional GPCR [human adenosine A2A receptor (A2AR)], in the total absence of detergent at any stage, by exploiting spontaneous encapsulation by styrene maleic acid (SMA) co-polymer direct from the membrane into a nanoscale SMA lipid particle (SMALP). Furthermore, the A2AR–SMALP, generated from yeast (Pichia pastoris) or mammalian cells, exhibited increased thermostability (∼5°C) compared with detergent [DDM (n-dodecyl-β-D-maltopyranoside)]-solubilized A2AR controls. The A2AR–SMALP was also stable when stored for prolonged periods at 4°C and was resistant to multiple freeze-thaw cycles, in marked contrast with the detergent-solubilized receptor. These properties establish the potential for using GPCR–SMALP in receptor-based drug discovery assays. Moreover, in contrast with nanodiscs stabilized by scaffold proteins, the non-proteinaceous nature of the SMA polymer allowed unobscured biophysical characterization of the embedded receptor. Consequently, CD spectroscopy was used to relate changes in secondary structure to loss of ligand binding ([3H]ZM241385) capability. SMALP-solubilization of GPCRs, retaining the annular lipid environment, will enable a wide range of therapeutic targets to be prepared in native-like state to aid drug discovery and understanding of GPCR molecular mechanisms.

We present a high-resolution cross-disciplinary analysis of kinship structure and social institutions in two Late Copper Age Bell Beaker culture cemeteries of South Germany containing 24 and 18 burials, of which 34 provided genetic information. By combining archaeological, anthropological, genetic and isotopic evidence we are able to document the internal kinship and residency structure of the cemeteries and the socially organizing principles of these local communities. The buried individuals represent four to six generations of two family groups, one nuclear family at the Alburg cemetery, and one seemingly more extended at Irlbach. While likely monogamous, they practiced exogamy, as six out of eight non-locals are women. Maternal genetic diversity is high with 23 different mitochondrial haplotypes from 34 individuals, whereas all males belong to one single Y-chromosome haplogroup without any detectable contribution from Y-chromosomes typical of the farmers who had been the sole inhabitants of the region hundreds of years before. This provides evidence for the society being patrilocal, perhaps as a way of protecting property among the male line, while in-marriage from many different places secured social and political networks and prevented inbreeding. We also find evidence that the communities practiced selection for which of their children (aged 0–14 years) received a proper burial, as buried juveniles were in all but one case boys, suggesting the priority of young males in the cemeteries. This is plausibly linked to the exchange of foster children as part of an expansionist kinship system which is well attested from later Indo-European-speaking cultural groups.

The International Stem Cell Initiative compared several commonly used approaches to assess human pluripotent stem cells (PSC). PluriTest predicts pluripotency through bioinformatic analysis of the transcriptomes of undifferentiated cells, whereas, embryoid body (EB) formation in vitro and teratoma formation in vivo provide direct tests of differentiation. Here we report that EB assays, analyzed after differentiation under neutral conditions and under conditions promoting differentiation to ectoderm, mesoderm, or endoderm lineages, are sufficient to assess the differentiation potential of PSCs. However, teratoma analysis by histologic examination and by TeratoScore, which estimates differential gene expression in each tumor, not only measures differentiation but also allows insight into a PSC’s malignant potential. Each of the assays can be used to predict pluripotent differentiation potential but, at this stage of assay development, only the teratoma assay provides an assessment of pluripotency and malignant potential, which are both relevant to the pre-clinical safety assessment of PSCs. The International Stem Cell Initiative tests methods in a multisite study to detect pluripotency and teratoma formation (PluriTest, Embryoid Body and Teratoma methods) in human pluripotent stem cells. Here, the authors provide guidelines for their application: only the teratoma assay offers evidence of malignant potential.

Background Suicide is the leading cause of preventable death in prisons. Deaths from suicide in prison are significantly, and persistently, elevated compared to those living in the community. Psychological therapies have been shown to be a potentially effective means of alleviating suicidal thoughts, plans and behaviours, but patients located in prison often have no access to evidence-based psychological interventions targeting suicide. The objectives of this programme of research are to investigate the clinical and cost effectiveness of a new psychological therapy programme delivered to male prisoners at risk of suicide. Methods The PROSPECT trial is a two-armed single blind, pragmatic, randomised controlled trial and will recruit a target sample size of 360 male prisoners, identified as at-risk of suicide, across 4 prisons in the North of England. Participants will be randomised to receive a psychological talking therapy (Cognitive Behavioural Suicide Prevention, CBSP) plus treatment as usual, or treatment as usual alone. Co-primary outcomes (Suicide Ideation and Suicide Behaviours), as well as related secondary outcomes, will be assessed at baseline and at 6-months follow-up. An intention to treat analysis will be conducted with primary stratification based on prison site and lifetime history of suicide attempt (yes/no). A nested qualitative process evaluation will investigate the nature and context in which the intervention is delivered, with specific focus upon the facilitators and barriers to the implementation of the therapy within prisons. Discussion The key outputs from this trial will be to determine whether a psychological therapy for suicidal prisoners is clinically and cost effective; and to generate a project implementation platform that identifies how best to implement the new intervention across the broader prison estate. Trial registration ISRCTN (reference ISRCTN14056534 https://www.isrctn.com/ISRCTN14056534 ; 24th September 2021). Registration confirmed prior to participant recruitment commencing. Modifications to protocol are listed on the study website at ISRCTN.

•Total joint arthroplastyis the only definitive surgical intervention for treating advanced hip or knee osteoarthritis.•Pre-surgery psychological distress is an important predictor of sub-optimal outcomes following TJA.•Pre-surgery MBSR© improves pain and function in people with psychological distress undergoing total joint arthroplasty.•A potential causal mechanism to explain these findings is yet to be identified. To evaluate the efficacy of Mindfulness-Based Stress Reduction (MBSR) in improving pain and physical function following total joint arthroplasty (TJA). Two-group, parallel-group, randomised controlled trial, conducted between September 2012 and May 2017. Single centre study conducted at a University-affiliated, tertiary hospital. People with arthritis scheduled for TJA, with a well-being score <40 (Short Form-12 Survey) were randomly allocated to a pre-surgery eight-week MBSR program or treatment as usual (TAU). Self-reported joint pain and function at 12 months post-surgery, assessed using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Secondary outcomes were knee stiffness and global improvement (WOMAC); physical and psychological well-being (Veterans RAND 12-item Health Survey); self-efficacy (Arthritis Self-Efficacy Scale); and mindfulness (5-Factor Mindfulness Questionnaire). 127 participants were randomised; 65 to MBSR and 62 to TAU, of which 45 participants allocated to the intervention and 56 participants allocated to usual care proceeded to surgery and 100 (99%) completed primary outcome measures. Greater improvements in knee pain (mean difference, -10.3 points, 95% CI -19.0 to -1.6; P = 0.021) and function (mean difference, -10.2 points, 95% CI -19.2 to -1.3; P = 0.025) at 12 months post-surgery were observed in the MBSR group compared to the TAU group. A between group difference in global scores (-9.5 points, 95% CI -17.9 to -1.1; P = 0.027) was also observed. No other differences in secondary outcomes were observed. MBSR improves post-surgery pain and function in people with psychological distress undergoing TJA. Further research is required to examine potential barriers to broader implementation and uptake.

This study investigates long-term socio-economic transformations in prehistoric Kuyavia, Poland, through stable isotope analysis of human, animal and plant remains, combined with radiocarbon dating. A total of 84 human individuals, spanning from the Middle Neolithic to the Middle Bronze Age (around 4100–1230 cal BC), were analysed to reconstruct ancient diet and subsistence strategies, and their implications to reveal possible social stratification. Isotopic values from cattle provide insights into changing herding strategies and adaptations to diverse environments, while analyses of charred cereals contextualize plant-based dietary contributions and crop management practices, including varying levels of manuring. The results indicate marked dietary and economic variability: Middle and Late Neolithic farming groups relied primarily on cereals and cattle, while early Corded Ware communities appear to have occupied marginal ecological niches with distinctive herding strategies. From the Middle Bronze Age, isotopic evidence demonstrates the first substantial incorporation of millet into the human diet, representing the earliest widespread use of a C4 crop in the region. Variability in nitrogen isotope values suggests differential access to animal protein and possible social inequalities, particularly during the Early Bronze Age. Together, these findings highlight both continuity and transformation in prehistoric economies over more than two millennia, offering a refined archaeological perspective on cultural evolution in East-Central Europe and demonstrating the potential of stable isotope analysis and radiocarbon dating to reveal aspects of past lifeways not visible in material culture alone.

BackgroundIdentification of multiple sclerosis (MS) cases in routine healthcare data repositories remains challenging. MS can have a protracted diagnostic process and is rarely identified as a primary reason for admission to the hospital. Difficulties in identification are compounded in systems that do not include insurance or payer information concerning drug treatments or non-notifiable disease.AimTo develop an algorithm to reliably identify MS cases within a national health data bank.MethodRetrospective analysis of the Secure Anonymised Information Linkage (SAIL) databank was used to identify MS cases using a novel algorithm. Sensitivity and specificity were tested using two existing independent MS datasets, one clinically validated and population-based and a second from a self-registered MS national registry.ResultsFrom 4 757 428 records, the algorithm identified 6194 living cases of MS within Wales on 31 December 2020 (prevalence 221.65 (95% CI 216.17 to 227.24) per 100 000). Case-finding sensitivity and specificity were 96.8% and 99.9% for the clinically validated population-based cohort and sensitivity was 96.7% for the self-declared registry population.DiscussionThe algorithm successfully identified MS cases within the SAIL databank with high sensitivity and specificity, verified by two independent populations and has important utility in large-scale epidemiological studies of MS.