Integrative single-cell analysis of cardiogenesis identifies developmental trajectories and non-coding mutations in congenital heart disease.

To define the multi-cellular epigenomic and transcriptional landscape of cardiac cellular development, we generated single-cell chromatin accessibility maps of human fetal heart tissues. We identified eight major differentiation trajectories involving primary cardiac cell types, each associated with dynamic transcription factor (TF) activity signatures. We contrasted regulatory landscapes of iPSC-derived cardiac cell types and their in vivo counterparts, which enabled optimization of in vitro differentiation of epicardial cells. Further, we interpreted sequence based deep learning models of cell-type-resolved chromatin accessibility profiles to decipher underlying TF motif lexicons. De novo mutations predicted to affect chromatin accessibility in arterial endothelium were enriched in congenital heart disease (CHD) cases vs. controls. In vitro studies in iPSCs validated the functional impact of identified variation on the predicted developmental cell types. This work thus defines the cell-type-resolved cis-regulatory sequence determinants of heart development and identifies disruption of cell type-specific regulatory elements in CHD.

Posttranslational Modifications Mediate the Structural Diversity of Tauopathy Strains.

Tau aggregation into insoluble filaments is the defining pathological hallmark of tauopathies. However, it is not known what controls the formation and templated seeding of strain-specific structures associated with individual tauopathies. Here, we use cryo-electron microscopy (cryo-EM) to determine the structures of tau filaments from corticobasal degeneration (CBD) human brain tissue. Cryo-EM and mass spectrometry of tau filaments from CBD reveal that this conformer is heavily decorated with posttranslational modifications (PTMs), enabling us to map PTMs directly onto the structures. By comparing the structures and PTMs of tau filaments from CBD and Alzheimer's disease, it is found that ubiquitination of tau can mediate inter-protofilament interfaces. We propose a structure-based model in which cross-talk between PTMs influences tau filament structure, contributing to the structural diversity of tauopathy strains. Our approach establishes a framework for further elucidating the relationship between the structures of polymorphic fibrils, including their PTMs, and neurodegenerative disease.

Spin wavepackets in the Kagome ferromagnet Fe3Sn2: Propagation and precursors.

The propagation of spin waves in magnetically ordered systems has emerged as a potential means to shuttle quantum information over large distances. Conventionally, the arrival time of a spin wavepacket at a distance, d, is assumed to be determined by its group velocity, vg. Here, we report time-resolved optical measurements of wavepacket propagation in the Kagome ferromagnet Fe3Sn2 that demonstrate the arrival of spin information at times significantly less than d/vg. We show that this spin wave "precursor" originates from the interaction of light with the unusual spectrum of magnetostatic modes in Fe3Sn2. Related effects may have far-reaching consequences toward realizing long-range, ultrafast spin wave transport in both ferromagnetic and antiferromagnetic systems.

Combinatorial design of ionizable lipid nanoparticles for muscle-selective mRNA delivery with minimized off-target effects.

Ionizable lipid nanoparticles (LNPs) pivotal to the success of COVID-19 mRNA (messenger RNA) vaccines hold substantial promise for expanding the landscape of mRNA-based therapies. Nevertheless, the risk of mRNA delivery to off-target tissues highlights the necessity for LNPs with enhanced tissue selectivity. The intricate nature of biological systems and inadequate knowledge of lipid structure-activity relationships emphasize the significance of high-throughput methods to produce chemically diverse lipid libraries for mRNA delivery screening. Here, we introduce a streamlined approach for the rapid design and synthesis of combinatorial libraries of biodegradable ionizable lipids. This led to the identification of iso-A11B5C1, an ionizable lipid uniquely apt for muscle-specific mRNA delivery. It manifested high transfection efficiencies in muscle tissues, while significantly diminishing off-targeting in organs like the liver and spleen. Moreover, iso-A11B5C1 also exhibited reduced mRNA transfection potency in lymph nodes and antigen-presenting cells, prompting investigation into the influence of direct immune cell transfection via LNPs on mRNA vaccine effectiveness. In comparison with SM-102, while iso-A11B5C1's limited immune transfection attenuated its ability to elicit humoral immunity, it remained highly effective in triggering cellular immune responses after intramuscular administration, which is further corroborated by its strong therapeutic performance as cancer vaccine in a melanoma model. Collectively, our study not only enriches the high-throughput toolkit for generating tissue-specific ionizable lipids but also encourages a reassessment of prevailing paradigms in mRNA vaccine design. This study encourages rethinking of mRNA vaccine design principles, suggesting that achieving high immune cell transfection might not be the sole criterion for developing effective mRNA vaccines.

Associating HIV-1 envelope glycoprotein structures with states on the virus observed by smFRET.

The HIV-1 envelope glycoprotein (Env) trimer mediates cell entry and is conformationally dynamic1-8. Imaging by single-molecule fluorescence resonance energy transfer (smFRET) has revealed that, on the surface of intact virions, mature pre-fusion Env transitions from a pre-triggered conformation (state 1) through a default intermediate conformation (state 2) to a conformation in which it is bound to three CD4 receptor molecules (state 3)8-10. It is currently unclear how these states relate to known structures. Breakthroughs in the structural characterization of the HIV-1 Env trimer have previously been achieved by generating soluble and proteolytically cleaved trimers of gp140 Env that are stabilized by a disulfide bond, an isoleucine-to-proline substitution at residue 559 and a truncation at residue 664 (SOSIP.664 trimers)5,11-18. Cryo-electron microscopy studies have been performed with C-terminally truncated Env of the HIV-1JR-FL strain in complex with the antibody PGT15119. Both approaches have revealed similar structures for Env. Although these structures have been presumed to represent the pre-triggered state 1 of HIV-1 Env, this hypothesis has never directly been tested. Here we use smFRET to compare the conformational states of Env trimers used for structural studies with native Env on intact virus. We find that the constructs upon which extant high-resolution structures are based predominantly occupy downstream conformations that represent states 2 and 3. Therefore, the structure of the pre-triggered state-1 conformation of viral Env that has been identified by smFRET and that is preferentially stabilized by many broadly neutralizing antibodies-and thus of interest for the design of immunogens-remains unknown.

Temporal Profile of Serum Neurofilament Light (NF-L) and Heavy (pNF-H) Level Associations With 6-Month Cognitive Performance in Patients With Moderate-Severe Traumatic Brain Injury.

OBJECTIVE: Identification of biomarkers of cognitive recovery after traumatic brain injury (TBI) will inform care and improve outcomes. This study assessed the utility of neurofilament (NF-L and pNF-H), a marker of neuronal injury, informing cognitive performance following moderate-to-severe TBI (msTBI). SETTING: Level 1 trauma center and outpatient via postdischarge follow-up. PARTICIPANTS: N = 94. Inclusion criteria: Glasgow Coma Scale score less than 13 or 13-15 with clinical evidence of moderate-to-severe injury traumatic brain injury on clinical imaging. Exclusion criteria: neurodegenerative condition, brain death within 3 days after injury. DESIGN: Prospective observational study. Blood samples were collected at several time points post-injury. Cognitive testing was completed at 6 months post-injury. MAIN MEASURES: Serum NF-L (Human Neurology 4-Plex B) pNF-H (SR-X) as measured by SIMOA Quanterix assay. Divided into 3 categorical time points at days post-injury (DPI): 0-15 DPI, 16-90 DPI, and >90 DPI. Cognitive composite comprised executive functioning measures derived from 3 standardized neuropsychological tests (eg, Delis-Kaplan Executive Function System: Verbal Fluency, California Verbal Learning Test, Second Edition, Wechsler Adult Intelligence Scale, Third Edition). RESULTS: pNF-H at 16-90 DPI was associated with cognitive outcomes including a cognitive-executive composite score at 6 months (ß = -.430, t34 = -3.190, P = .003). CONCLUSIONS: Results suggest that "subacute" elevation of serum pNF-H levels may be associated with protracted/poor cognitive recovery from msTBI and may be a target for intervention. Interpretation is limited by small sample size and including only those who were able to complete cognitive testing.

The comparative effectiveness of combined hydrodilatation/corticosteroid procedure with two different quantities for adhesive capsulitis.

OBJECTIVE: To assess the efficacy of injecting various amounts of fluid into the shoulder joints for capsule distension in patients with adhesive capsulitis. DESIGN: A randomized controlled trial. SETTING: Outpatient clinic of a tertiary care centre. PARTICIPANTS: Eighty-four patients with adhesive capsulitis underwent a baseline (time0), 6 weeks (time1), and 12 weeks (time2) follow-up after hydrodilitation. INTERVENTION: Group 1 (n = 42) received 20 ml of lidocaine, steroid, and saline hydrodilatation via posterior glenohumeral recess, while Group 2 (n = 42) received 10 ml of lidocaine, steroid, and saline hydrodilitation. MAIN MEASURES: The primary outcome was the visual analogue scale for pain. The secondary outcomes were shoulder pain and disability index (SPADI) and ROM of the shoulder. RESULTS: There was a significant reduce in VAS scores for pain, SPADI scores, and increased shoulder ROM in both groups over time; however, the group-by-time interactions for any of the outcomes between groups were not significant except VAS pain in motion. Post-hoc pairwise analysis of the marginal effect of time and group showed that the significant difference of VAS in motion is due to time effect: time1 vs time0 (95% CI -4.09 to -2.68), time2 vs time0 (-4.21 to -2.77), and time2 vs time1 (-0.83 to 0.63), without between-group difference: group 1 vs group 2 (-0.38 to 0.59). CONCLUSION: Our study suggests hydrodilatation achieved an optimal effect at time1 for patients with adhesive capsulitis in both groups, and adding more saline offers additional benefits in flexion and external roatation until time2.

Efficacy of combined ultrasound-guided hydrodilatation with hyaluronic acid and physical therapy in patients with adhesive capsulitis: A randomised controlled trial.

OBJECTIVE: To evaluate the therapeutic effect of combining ultrasound-guided hydrodilatation with hyaluronic acid and physical therapy compared with physical therapy alone in patients with adhesive capsulitis. DESIGN: A prospective, single-blinded, randomised controlled trial. SETTING: Single medical centre. PARTICIPANTS: Patients with adhesive capsulitis (N = 62) were divided into group A: ultrasound-guided hydrodilatation with hyaluronic acid + physical therapy (N = 31) and group B: physical therapy alone (N = 31). INTERVENTIONS: Group A received three doses of ultrasound-guided hydrodilatation with hyaluronic acid-based injectates (20 mL in total). Both groups underwent structured physical therapy. OUTCOME MEASURES: The primary outcome measure was Constant score, while secondary outcomes included Shoulder Pain and Disability Index score, numerical rating scale (at rest, night, and during motion), 36-item Short Form Health Survey, and range of motion of the shoulder. All measurements were collected at baseline, 6 weeks, and 12 weeks post-injection. RESULTS: At week 12, the Constant scores were 68.29 ± 14.55 and 62.77 ± 14.44 for groups A and B, respectively. There was a greater reduction in the Constant score, Shoulder Pain and Disability Index, and numerical rating scale between the baseline and 6 weeks and between the baseline and 12 weeks in group A (Constant score: p < 0.05, Shoulder Pain and Disability Index: p < 0.01, and numerical rating scale: p < 0.05). CONCLUSION: The combination of ultrasound-guided hydrodilatation with hyaluronic acid in conjunction with physical therapy provides additional benefits compared to physical therapy alone for the treatment of adhesive capsulitis at up to 12 weeks. TRIAL REGISTRATION: ClinicalTrials.gov: NCT02708706.

There Is Wide Variation in Platelet-rich Plasma Injection Pricing: A United States Nationwide Study of Top Orthopaedic Hospitals.

BACKGROUND: Demand for platelet-rich plasma (PRP) injections for osteoarthritis has dramatically increased in recent years despite conflicting evidence regarding its efficacy and highly variable pricing in the top orthopaedic centers in the United States, because PRP is typically not covered by insurance. A previous study investigating the mean price of PRP injections obtained information only from centers advertising online the availability of PRP injections. Thus, there is a need for further clarification of the overall availability and variability in cost of PRP injections in the orthopaedic community as well as an analysis of relevant regional demographic and hospital characteristics that could be associated with PRP pricing. QUESTIONS/PURPOSES: Our study purposes were to (1) report the availability and price variation of knee PRP injections at top-ranked United States orthopaedic centers, (2) characterize the availability of pricing information for a PRP injection over the telephone, (3) determine whether hospital characteristics (Orthopaedic Score [ U . S. News & World Report measure of hospital orthopaedic department performance], size, teaching status, and rural-urban status) were associated with PRP injection availability and pricing, and (4) characterize the price variation, if it exists, of PRP injections in three metropolitan areas and individual institutions. METHODS: In this prospective study, a scripted telephone call to publicly listed clinic telephone numbers was used to determine the availability and price estimate (amount to be paid by the patient) of a PRP injection for knee osteoarthritis from the top 25 hospitals from each United States Census region selected from the U.S. News & World Report ranking of best hospitals for orthopaedics. Univariable analyses examined factors associated with PRP injection availability and willingness to disclose pricing, differences across regions, and the association between hospital characteristics (Orthopaedic Score, size, teaching status, and rural-urban status) and pricing. The Orthopaedic Score is a score assigned to each hospital by U . S. News & World Report as a measure of hospital performance based partly on patient outcomes, with higher scores indicating better outcomes. RESULTS: Overall, 87% (87 of 100) of respondents stated they offered PRP injections. Pricing ranged from USD 350 to USD 2815 (median USD 800) per injection, with the highest prices in the Northeast. The largest price range was in the Midwest, where more than two-thirds of PRP injections given at hospitals that disclosed pricing cost USD 500 to USD 1000. Of the hospitals that offered PRP injections, 68% (59 of 87) were willing to disclose price information over the telephone. PRP injection pricing was inversely correlated with hospital Orthopaedic Score (-3% price change [95% CI -5% to -1%]; p = 0.01) and not associated with any of the other hospital characteristics that were studied, such as patient population median income and total hospital expenses. An intracity analysis revealed wide variations in PRP pricing in all metropolitan areas that were analyzed, ranging from a minimum of USD 300 within 10 miles of metropolitan area B to a maximum of USD 1269 within 20 miles of metropolitan area C. CONCLUSION: We found that although PRP injections are widely available, pricing continues to be a substantial financial burden on patients, with large price variability among institutions. We also found that if patients are willing to shop around in a metropolitan area, there is potential to save a meaningful amount of money. CLINICAL RELEVANCE: As public interest in biologics in orthopaedic surgery increases, knowledge of its pricing should be clarified to consumers. The debated efficacy of PRP injections, combined with our findings that it is an expensive out-of-pocket procedure, suggests that PRP has limited cost-effectiveness, with variable, discrete pricing. As such, the price of PRP injections should be clearly disclosed to patients so they can make informed healthcare decisions.

Balloon Spacer Implant is an "Intermediate Value" Innovation Relative to Partial Repair for Full-Thickness Massive Rotator Cuff Repairs: A Cost-Utility Analysis.

PURPOSE: The purpose of this study was to evaluate the cost-utility of a Balloon Spacer implant relative to partial repair (PR) for the surgical treatment of full-thickness massive rotator cuff tears (MRCT). METHODS: A decision-analytic model comparing Balloon Spacer versus PR was developed using data from a prospective, randomized, single-blinded, multi-center controlled trial of 184 randomized patients. Our model was constructed based on the various event pathways a patient could have after the procedure. The probability that each patient progressed to a given outcome and the quality-adjusted life years (QALY) associated with each outcome were derived from the clinical trial data. Incremental cost utility ratio (ICUR) and incremental net monetary benefit (INMB) were calculated based on a probabilistic sensitivity analysis using Monte Carlo simulations of 1,000 hypothetical patients progressing through the decision-analytic model. One-way sensitivity and threshold analyses were performed by varying cost, event probability, and QALY estimates. RESULTS: Balloon Spacer had an ICUR of $106,851 (95% CI, $96,317 to $119,143) relative to PR for surgical treatment of MRCT. Across all patients, Balloon Spacer was associated with greater 2-year QALY gain compared to PR (0.20 ± 0.02 for Balloon Spacer versus 0.18 ± 0.02 for PR), but with substantially higher total 2-year cost ($9,701 ± $939 for Balloon Spacer versus $6,315 ± $627 for PR). PR was associated with a positive INMB of $1,802 (95% CI, $1,653 to $1,951) over Balloon Spacer at the $50,000/QALY willingness-to-pay (WTP) threshold. CONCLUSIONS: Compared to PR, Balloon Spacer is an "intermediate value" innovation for treatment of MRCT over a 2-year postoperative period with an ICUR value that falls within the $50,000 to $150,000 WTP threshold.

Ambulatory Surgery Centers Reduce Patient Out-of-Pocket Expenditures for Isolated Arthroscopic Rotator Cuff Repair, but Patient Out-of-Pocket Expenditures Are Increasing at a Faster Rate Than Total Healthcare Utilization Reimbursement From Payers.

PURPOSE: To categorize and trend annual out-of-pocket expenditures for arthroscopic rotator cuff repair (RCR) patients relative to total healthcare utilization (THU) reimbursement and compare drivers of patient out-of-pocket expenditures (POPE) in a granular fashion via analyses by insurance type and surgical setting. METHODS: Patients who underwent outpatient arthroscopic RCR in the United States from 2013 to 2018 were identified from the IBM MarketScan Database. Primary outcome variables were total POPE and THU reimbursement, which were calculated for all claims in the 9-month perioperative period. Trends in outcome variables over time and differences across insurance types were analyzed. Multivariable analysis was performed to investigate drivers of POPE. RESULTS: A total of 52,330 arthroscopic RCR patients were identified. Between 2013 and 2018, median POPE increased by 47.5% ($917 to $1,353), and median THU increased by 9.3% ($11,964 to $13,076). Patients with high deductible insurance plans paid $1,910 toward their THU, 52.5% more than patients with preferred provider plans ($1,253, P = .001) and 280.5% more than patients with managed care plans ($502, P = .001). All components of POPE increased over the study period, with the largest observed increase being POPE for the immediate procedure (P = .001). On multivariable analysis, out-of-network facility, out-of-network surgeon, and high-deductible insurance most significantly increased POPE. CONCLUSIONS: POPE for arthroscopic RCR increased at a higher rate than THU over the study period, demonstrating that patients are paying an increasing proportion of RCR costs. A large percentage of this increase comes from increasing POPE for the immediate procedure. Out-of-network facility status increased POPE 3 times more than out-of-network surgeon status, and future cost-optimization strategies should focus on facility-specific reimbursements in particular. Last, ambulatory surgery centers (ASCs) significantly reduced POPE, so performing arthroscopic RCRs at ASCs is beneficial to cost-minimization efforts. CLINICAL RELEVANCE: This study highlights that although payers have increased reimbursement for RCR, patient out-of-pocket expenditures have increased at a much higher rate. Furthermore, this study elucidates trends in and drivers of patient out-of-pocket payments for RCR, providing evidence for development of cost-optimization strategies and counseling of patients undergoing RCR.

Socioeconomic Factors Including Patient Income, Education Level, and Health Insurance Influence Postoperative Secondary Surgery and Hospitalization Rates Following Hip Arthroscopy.

PURPOSE: To evaluate a large cross-sectional sample of patients utilizing administrative database records and analyze the effects of income, insurance type, and education level on outcomes after hip arthroscopy, including 2-year revision surgery, conversion to total hip arthroplasty (THA), and 90-day hospitalizations. METHODS: Current Procedural Terminology codes were used to query the PearlDiver Mariner database from October 2015 to January 2020 for patients undergoing hip arthroscopy with a minimum 2-year follow-up. Patients were categorized by mean family income in their zip code of residence (MFIR), health insurance type, and educational attainment in their zip code of residence (EAR). Two-year revision arthroscopy, conversion to THA, and 90-day hospital readmissions or emergency department (ED) visits were analyzed along socioeconomic strata. RESULTS: Multivariate analysis of 33,326 patients revealed that patients with MFIR between $30,000 and $70,000 had lower odds of 2-year revision arthroscopy (odds ratio [OR], 0.63; P < .001), THA conversion (OR, 0.76; P = .050), and 90-day readmission (OR, 0.53; P = .007) compared to MFIR >$100,000. Compared to patients with commercial insurance, patients with Medicare had lower odds of revision arthroscopy (OR, 0.60; P = .035) and THA conversion (OR, 0.46, P < .001) but greater odds of 90-day readmission (OR, 1.74; P = .007). Patients with Medicaid had higher odds of 90-day ED visits (OR, 1.84; P < .001). Patients with low EAR had higher odds of revision arthroscopy (OR, 1.42; P = .005) and THA conversion (OR, 1.58; P = .002) compared to those with high EAR. CONCLUSIONS: Following hip arthroscopy, patients residing in areas with lower mean family income were less likely to undergo reoperations and readmissions. Medicare patients showed lower reoperation but higher readmission odds, while Medicaid patients showed higher odds of ED visits. Additionally, higher educational attainment in the zip code of residence is protective against future reoperation. LEVEL OF EVIDENCE: Level III, retrospective case series.

Decentralised Global Service Discovery for the Internet of Things.

The Internet of Things (IoT) consists of millions of devices deployed over hundreds of thousands of different networks, providing an ever-expanding resource to improve our understanding of and interactions with the physical world. Global service discovery is key to realizing the opportunities of the IoT, spanning disparate networks and technologies to enable the sharing, discovery, and utilisation of services and data outside of the context in which they are deployed. In this paper, we present Decentralised Service Registries (DSRs), a novel trustworthy decentralised approach to global IoT service discovery and interaction, building on DSF-IoT to allow users to simply create and share public and private service registries, to register and query for relevant services, and to access both current and historical data published by the services they discover. In DSR, services are registered and discovered using signed objects that are cryptographically associated with the registry service, linked into a signature chain, and stored and queried for using a novel verifiable DHT overlay. In contrast to existing centralised and decentralised approaches, DSRs decouple registries from supporting infrastructure, provide privacy and multi-tenancy, and support the verification of registry entries and history, service information, and published data to mitigate risks of service impersonation or the alteration of data. This decentralised approach is demonstrated through the creation and use of a DSR to register and search for real-world IoT devices and their data as well as qualified using a scalable cluster-based testbench for the high-fidelity emulation of peer-to-peer applications. DSRs are evaluated against existing approaches, demonstrating the novelty and utility of DSR to address key IoT challenges and enable the sharing, discovery, and use of IoT services.

Validation of Machine Learning-Aided and Power Line Communication-Based Cable Monitoring Using Measurement Data.

The implementation of power line communications (PLC) in smart electricity grids provides us with exciting opportunities for real-time cable monitoring. In particular, effective fault classification and estimation methods employing machine learning (ML) models have been proposed in the recent past. Often, the research works presenting PLC for ML-aided cable diagnostics are based on the study of synthetically generated channel data. In this work, we validate ML-aided diagnostics by integrating measured channels. Specifically, we consider the concatenation of clustering as a data pre-processing procedure and principal component analysis (PCA)-based dimension reduction for cable anomaly detection. Clustering and PCA are trained with measurement data when the PLC network is working under healthy conditions. A possible cable anomaly is then identified from the analysis of the PCA reconstruction error for a test sample. For the numerical evaluation of our scheme, we apply an experimental setup in which we introduce degradations to power cables. Our results show that the proposed anomaly detector is able to identify a cable degradation with high detection accuracy and low false alarm rate.

Transcriptomic Signatures of Neuronally Derived Extracellular Vesicles Reveal the Presence of Olfactory Receptors in Clinical Samples from Traumatic Brain Injury Patients.

Traumatic brain injury (TBI) is defined as an injury to the brain by external forces which can lead to cellular damage and the disruption of normal central nervous system functions. The recently approved blood-based biomarkers GFAP and UCH-L1 can only detect injuries which are detectable on CT, and are not sensitive enough to diagnose milder injuries or concussion. Exosomes are small microvesicles which are released from the cell as a part of extracellular communication in normal as well as diseased states. The objective of this study was to identify the messenger RNA content of the exosomes released by injured neurons to identify new potential blood-based biomarkers for TBI. Human severe traumatic brain injury samples were used for this study. RNA was isolated from neuronal exosomes and total transcriptomic sequencing was performed. RNA sequencing data from neuronal exosomes isolated from serum showed mRNA transcripts of several neuronal genes. In particular, mRNAs of several olfactory receptor genes were present at elevated concentrations in the neuronal exosomes. Some of these genes were OR10A6, OR14A2, OR6F1, OR1B1, and OR1L1. RNA sequencing data from exosomes isolated from CSF showed a similar elevation of these olfactory receptors. We further validated the expression of these samples in serum samples of mild TBI patients, and a similar up-regulation of these olfactory receptors was observed. The data from these experiments suggest that damage to the neurons in the olfactory neuroepithelium as well as in the brain following a TBI may cause the release of mRNA from these receptors in the exosomes. Hence, olfactory receptors can be further explored as biomarkers for the diagnosis of TBI.

Aptamer Technologies in Neuroscience, Neuro-Diagnostics and Neuro-Medicine Development.

Aptamers developed using in vitro Systematic Evolution of Ligands by Exponential Enrichment (SELEX) technology are single-stranded nucleic acids 10-100 nucleotides in length. Their targets, often with specificity and high affinity, range from ions and small molecules to proteins and other biological molecules as well as larger systems, including cells, tissues, and animals. Aptamers often rival conventional antibodies with improved performance, due to aptamers' unique biophysical and biochemical properties, including small size, synthetic accessibility, facile modification, low production cost, and low immunogenicity. Therefore, there is sustained interest in engineering and adapting aptamers for many applications, including diagnostics and therapeutics. Recently, aptamers have shown promise as early diagnostic biomarkers and in precision medicine for neurodegenerative and neurological diseases. Here, we critically review neuro-targeting aptamers and their potential applications in neuroscience research, neuro-diagnostics, and neuro-medicine. We also discuss challenges that must be overcome, including delivery across the blood-brain barrier, increased affinity, and improved in vivo stability and in vivo pharmacokinetic properties.

Functional Selection of Tau Oligomerization-Inhibiting Aptamers.

Pathological hyperphosphorylation and aggregation of microtubule-associated Tau protein contribute to Alzheimer's Disease (AD) and other related tauopathies. Currently, no cure exists for Alzheimer's Disease. Aptamers offer significant potential as next-generation therapeutics in biotechnology and the treatment of neurological disorders. Traditional aptamer selection methods for Tau protein focus on binding affinity rather than interference with pathological Tau. In this study, we developed a new selection strategy to enrich DNA aptamers that bind to surviving monomeric Tau protein under conditions that would typically promote Tau aggregation. Employing this approach, we identified a set of aptamer candidates. Notably, BW1c demonstrates a high binding affinity (Kd=6.6 nM) to Tau protein and effectively inhibits arachidonic acid (AA)-induced Tau protein oligomerization and aggregation. Additionally, it inhibits GSK3ß-mediated Tau hyperphosphorylation in cell-free systems and okadaic acid-mediated Tau hyperphosphorylation in cellular milieu. Lastly, retro-orbital injection of BW1c tau aptamer shows the ability to cross the blood brain barrier and gain access to neuronal cell body. Through further refinement and development, these Tau aptamers may pave the way for a first-in-class neurotherapeutic to mitigate tauopathy-associated neurodegenerative disorders.

Combined GFAP, NFL, Tau, and UCH-L1 panel increases prediction of outcomes in neonatal encephalopathy.

BACKGROUND: Neuroprognostication in neonates with neonatal encephalopathy (NE) may be enhanced by early serial measurement of a panel of four brain-specific biomarkers. METHODS: To evaluate serum biomarkers, 40 NE samples and 37 healthy neonates from a biorepository were analyzed. Blood samples were collected at 0-6, 12, 24, 48, and 96 h of life. MRI provided a short-term measure of injury. Long-term outcomes included death or a Bayley III score at 17-24 months of age. RESULTS: Glial fibrillary acidic protein (GFAP), ubiquitin c-terminal hydrolase-L1 (UCH-L1), and Tau peaked at 0-6 h of life, while neurofilament light chain (NFL) peaked at 96 h of life. These four marker concentrations at 96 h of life differentiated moderate/severe from none/mild brain injury by MRI, while GFAP and Tau showed early discrimination. For long-term outcomes, GFAP, NFL, Tau, and UCH-L1 could differentiate a poor outcome vs good outcome as early as 0-6 h of life, depending on the Bayley domain, and a combination of the four markers enhanced the sensitivity and specificity. Machine learning trajectory analyses identified upward trajectory patients with a high concordance to poor outcomes. CONCLUSION: GFAP, NFL, Tau, and UCH-L1 may be of neuroprognostic significance after NE. IMPACT: Serial measurements of GFAP, NFL, Tau, and UCH-L1 show promise in aiding the bedside clinician in making treatment decisions in neonatal encephalopathy. The panel of four neuroproteins increased the ability to predict neurodevelopmental outcomes. The study utilized a trajectory analysis that enabled predictive modeling. A panel approach provides the bedside clinician with objective data to individualize care. This study provides the foundation to develop a point of care device in the future.

Complex Autoantibody Responses Occur following Moderate to Severe Traumatic Brain Injury.

Most of the variation in outcome following severe traumatic brain injury (TBI) remains unexplained by currently recognized prognostic factors. Neuroinflammation may account for some of this difference. We hypothesized that TBI generated variable autoantibody responses between individuals that would contribute to outcome. We developed a custom protein microarray to detect autoantibodies to both CNS and systemic Ags in serum from the acute-phase (the first 7 d), late (6-12 mo), and long-term (6-13 y) intervals after TBI in human patients. We identified two distinct patterns of immune response to TBI. The first was a broad response to the majority of Ags tested, predominantly IgM mediated in the acute phase, then IgG dominant at late and long-term time points. The second was responses to specific Ags, most frequently myelin-associated glycopeptide (MAG), which persisted for several months post-TBI but then subsequently resolved. Exploratory analyses suggested that patients with a greater acute IgM response experienced worse outcomes than predicted from current known risk factors, suggesting a direct or indirect role in worsening outcome. Furthermore, late persistence of anti-MAG IgM autoantibodies correlated with raised serum neurofilament light concentrations at these time points, suggesting an association with ongoing neurodegeneration over the first year postinjury. Our results show that autoantibody production occurs in some individuals following TBI, can persist for many years, and is associated with worse patient outcome. The complexity of responses means that conventional approaches based on measuring responses to single antigenic targets may be misleading.