Propagation of Protein Aggregation in Neurodegenerative Diseases.

Most common neurodegenerative diseases feature deposition of protein amyloids and degeneration of brain networks. Amyloids are ordered protein assemblies that can act as templates for their own replication through monomer addition. Evidence suggests that this characteristic may underlie the progression of pathology in neurodegenerative diseases. Many different amyloid proteins, including Aß, tau, and α-synuclein, exhibit properties similar to those of infectious prion protein in experimental systems: discrete and self-replicating amyloid structures, transcellular propagation of aggregation, and transmissible neuropathology. This review discusses the contribution of prion phenomena and transcellular propagation to the progression of pathology in common neurodegenerative diseases such as Alzheimer's and Parkinson's. It reviews fundamental events such as cell entry, amplification, and transcellular movement. It also discusses amyloid strains, which produce distinct patterns of neuropathology and spread through the nervous system. These concepts may impact the development of new diagnostic and therapeutic strategies.

Tau seeding without tauopathy.

Neurodegenerative tauopathies such as Alzheimer's disease (AD) are caused by brain accumulation of tau assemblies. Evidence suggests tau functions as a prion, and cells and animals can efficiently propagate unique, transmissible tau pathologies. This suggests a dedicated cellular replication machinery, potentially reflecting a normal physiologic function for tau seeds. Consequently, we hypothesized that healthy control brains would contain seeding activity. We have recently developed a novel monoclonal antibody (MD3.1) specific for tau seeds. We used this antibody to immunopurify tau from the parietal and cerebellar cortices of 19 healthy subjects without any neuropathology, ranging 19 to 65 years. We detected seeding in lysates from the parietal cortex, but not in the cerebellum. We also detected no seeding in brain homogenates from wildtype or human tau knockin mice, suggesting that cellular/genetic context dictates development of seed-competent tau. Seeding did not correlate with subject age or brain tau levels. We confirmed our essential findings using an orthogonal assay, real-time quaking-induced conversion, which amplifies tau seeds in vitro. Dot blot analyses revealed no AT8 immunoreactivity above background levels in parietal and cerebellar extracts and ∼1/100 of that present in AD. Based on binding to a panel of antibodies, the conformational characteristics of control seeds differed from AD, suggesting a unique underlying assembly, or structural ensemble. Tau's ability to adopt self-replicating conformations under nonpathogenic conditions may reflect a normal function that goes awry in disease states.

Anti-tau antibodies targeting a conformation-dependent epitope selectively bind seeds.

Neurodegenerative tauopathies are caused by the transition of tau protein from a monomer to a toxic aggregate. They include Alzheimer disease (AD), progressive supranuclear palsy (PSP), corticobasal degeneration (CBD), and Pick disease (PiD). We have previously proposed that tau monomer exists in two conformational ensembles: an inert form (Mi), which does not self-assemble, and seed-competent form (Ms), which self-assembles and templates ordered assembly growth. We proposed that cis/trans isomerization of tau at P301, the site of dominant disease-associated S/L missense mutations, might underlie the transition of wild-type tau to a seed-competent state. Consequently, we created monoclonal antibodies using non-natural antigens consisting of fluorinated proline (P∗) at the analogous P270 in repeat 1 (R1), biased toward the trans-configuration at either the R1/R2 (TENLKHQP∗GGGKVQIINKK) or the R1/R3 (TENLKHQP∗GGGKVQIVYK) interfaces. Two antibodies, MD2.2 and MD3.1, efficiently immunoprecipitated soluble seeds from AD and PSP but not CBD or PiD brain samples. The antibodies efficiently stained brain samples of AD, PSP, and PiD, but not CBD. They did not immunoprecipitate or immunostain tau from the control brain. Creation of potent anti-seed antibodies based on the trans-proline epitope implicates local unfolding around P301 in pathogenesis. MD2.2 and MD3.1 may also be useful for therapy and diagnosis.

Docking for Molecules That Bind in a Symmetric Stack with SymDOCK.

Discovering ligands for amyloid fibrils, such as those formed by the tau protein, is an area of great current interest. In recent structures, ligands bind in stacks in the tau fibrils to reflect the rotational and translational symmetry of the fibril itself; in these structures, the ligands make few interactions with the protein but interact extensively with each other. To exploit this symmetry and stacking, we developed SymDOCK, a method to dock molecules that follow the protein's symmetry. For each prospective ligand pose, we apply the symmetry operation of the fibril to generate a self-interacting and fibril-interacting stack, checking that doing so will not cause a clash between the original molecule and its image. Absent a clash, we retain that pose and add the ligand-ligand van der Waals energy to the ligand's docking score (here using DOCK3.8). We can check these geometries and energies using an implementation of ANI, a neural-network-based quantum-mechanical evaluation of the ligand stacking energies. In retrospective calculations, symmetry docking can reproduce the poses of three tau PET tracers whose structures have been determined. More convincingly, in a prospective study, SymDOCK predicted the structure of the PET tracer MK-6240 bound in a symmetrical stack to AD PHF tau before that structure was determined; the docked pose was used to determine how MK-6240 fit the cryo-EM density. In proof-of-concept studies, SymDOCK enriched known ligands over property-matched decoys in retrospective screens without sacrificing docking speed and can address large library screens that seek new symmetrical stackers. Future applications of this approach will be considered.

Do veterans with risky substance use (RSU) use distinct pain treatment modalities?

BACKGROUND AND OBJECTIVES: Risky substance use (RSU) is common among people with chronic pain and is associated with worse pain treatment outcomes. Nonopioid treatment is recommended, but it is unknown whether people with RSU use different or fewer pain treatment modalities. This study describes use of different pain treatments by veterans with and without RSU and those receiving versus not receiving opioid medication. METHODS: Veterans (N = 924) who filed service-connected disability claims related to musculoskeletal conditions and rated their pain four or higher on the Numeric Rating Scale, reported on 25 different pain services in the preceding 90 days. Recent RSU was identified via Alcohol, Smoking, and Substance Involvement Test (ASSIST) cutoffs and/or nail sample toxicology. RESULTS: Overall, RSU was not associated with number of provider-delivered or self-delivered pain modalities. Over-the-counter medications (71%), self-structured exercise (69%), and nonopioid prescription medications (38%) were the most used modalities. Veterans receiving prescribed opioids (8.4%) were more likely to see primary care, receive injections, and attend exercise and/or meditation classes, compared to those without opioid prescriptions. DISCUSSION AND CONCLUSIONS: Opioid and nonopioid pain treatment utilization did not differ based on RSU, and those prescribed opioids were more likely to engage in other nonopioid pain treatments. Regardless of RSU, veterans appear willing to try provider-delivered (58%) and self-delivered (79%) pain treatment. SCIENTIFIC SIGNIFICANCE: In this first-ever evaluation of 25 different pain treatment modalities among veterans with and without RSU, people with RSU did not use less treatment modalities.

A novel peptide-based tau aggregation inhibitor as a potential therapeutic for Alzheimer's disease and other tauopathies.

INTRODUCTION: As aggregation underpins Tau toxicity, aggregation inhibitor peptides may have disease-modifying potential. They are therefore currently being designed and target either the 306VQIVYK311 aggregation-promoting hotspot found in all Tau isoforms or the 275VQIINK280 aggregation-promoting hotspot found in 4R isoforms. However, for any Tau aggregation inhibitor to potentially be clinically relevant for other tauopathies, it should target both hotspots to suppress aggregation of Tau isoforms, be stable, cross the blood-brain barrier, and rescue aggregation-dependent Tau phenotypes in vivo. METHODS: We developed a retro-inverso, stable D-amino peptide, RI-AG03 [Ac-rrrrrrrrGpkyk(ac)iqvGr-NH2], based on the 306VQIVYK311 hotspots which exhibit these disease-relevant attributes. RESULTS: Unlike other aggregation inhibitors, RI-AG03 effectively suppresses aggregation of multiple Tau species containing both hotspots in vitro and in vivo, is non-toxic, and suppresses aggregation-dependent neurodegenerative and behavioral phenotypes. DISCUSSION: RI-AG03 therefore meets many clinically relevant requirements for an anti-aggregation Tau therapeutic and should be explored further for its disease-modifying potential for Tauopathies. HIGHLIGHTS: Our manuscript describes the development of a novel peptide inhibitor of Tau aggregation, a retro-inverso, stable D-amino peptide called RI-AG03 that displays many clinically relevant attributes. We show its efficacy in preventing Tau aggregation in both in vitro and in vivo experimental models while being non-toxic to cells. RI-AG03 also rescues a biosensor cell line that stably expresses Tau repeat domains with the P301S mutation fused to Cer/Clo and rescues aggregation-dependent phenotypes in vivo, suppressing neurodegeneration and extending lifespan. Collectively our data describe several properties and attributes of RI-AG03 that make it a promising disease-modifying candidate to explore for reducing pathogenic Tau aggregation in Tauopathies such as Alzheimer's disease. Given the real interest in reducing Tau aggregation and the potential clinical benefit of using such agents in clinical practice, RI-AG03 should be investigated further for the treatment of Tauopathies after validation in mammalian models. Tau aggregation inhibitors are the obvious first choice as Tau-based therapies as much of Tau-mediated toxicity is aggregation dependent. Indeed, there are many research efforts focusing on this therapeutic strategy with aggregation inhibitors being designed against one of the two aggregation-promoting hotspots of the Tau protein. To our knowledge, RI-AG03 is the only peptide aggregation inhibitor that inhibits aggregation of Tau by targeting both aggregation-promoting hotspot motifs simultaneously. As such, we believe that our study will have a significant impact on drug discovery efforts in this arena.

Seed-competent tau monomer initiates pathology in a tauopathy mouse model.

Tau aggregation into ordered assemblies causes neurodegenerative tauopathies. We previously reported that tau monomer exists in either inert (Mi) or seed-competent (Ms) conformational ensembles and that Ms encodes strains, that is, unique, self-replicating, biologically active assemblies. It is unknown if disease begins with Ms formation followed by fibril assembly or if Ms derives from fibrils and is therefore an epiphenomenon. Here, we studied a tauopathy mouse model (PS19) that expresses full-length mutant human (1N4R) tau (P301S). Insoluble tau seeding activity appeared at 2 months of age and insoluble tau protein assemblies by immunoblot at 3 months. Tau monomer from mice aged 1 to 6 weeks, purified using size-exclusion chromatography, contained soluble seeding activity at 4 weeks, before insoluble material or larger assemblies were observed, with assemblies ranging from n = 1 to 3 tau units. By 5 to 6 weeks, large soluble assemblies had formed. This indicated that the first detectable pathological forms of tau were in fact Ms. We next examined posttranslational modifications of tau monomer from 1 to 6 weeks. We detected no phosphorylation unique to Ms in PS19 or human Alzheimer's disease brains. We conclude that tauopathy begins with formation of the Ms monomer, whose activity is phosphorylation independent. Ms then self assembles to form oligomers before it forms insoluble fibrils. The conversion of tau monomer from Mi to Ms thus constitutes the first detectable step in the initiation of tauopathy in this mouse model, with obvious implications for the origins of tauopathy in humans.

The dual fates of exogenous tau seeds: Lysosomal clearance versus cytoplasmic amplification.

Tau assembly movement from the extracellular to intracellular space may underlie transcellular propagation of neurodegenerative tauopathies. This begins with tau binding to cell surface heparan sulfate proteoglycans, which triggers macropinocytosis. Pathological tau assemblies are proposed then to exit the vesicular compartment as "seeds" for replication in the cytoplasm. Tau uptake is highly efficient, but only ∼1 to 10% of cells that endocytose aggregates exhibit seeding. Consequently, we studied fluorescently tagged full-length (FL) tau fibrils added to native U2OS cells or "biosensor" cells expressing FL tau or repeat domain. FL tau fibrils bound tubulin. Seeds triggered its aggregation in multiple locations simultaneously in the cytoplasm, generally independent of visible exogenous aggregates. Most exogenous tau trafficked to the lysosome, but fluorescence imaging revealed a small percentage that steadily accumulated in the cytosol. Intracellular expression of Gal3-mRuby, which binds intravesicular galactosides and forms puncta upon vesicle rupture, revealed no evidence of vesicle damage following tau exposure, and most seeded cells had no evidence of endolysosome rupture. However, live-cell imaging indicated that cells with pre-existing Gal3-positive puncta were seeded at a slightly higher rate than the general population, suggesting a potential predisposing role for vesicle instability. Clearance of tau seeds occurred rapidly in both vesicular and cytosolic fractions. The lysosome/autophagy inhibitor bafilomycin inhibited vesicular clearance, whereas the proteasome inhibitor MG132 inhibited cytosolic clearance. Tau seeds that enter the cell thus have at least two fates: lysosomal clearance that degrades most tau, and entry into the cytosol, where seeds amplify, and are cleared by the proteasome.

RNA induces unique tau strains and stabilizes Alzheimer's disease seeds.

Tau aggregation underlies neurodegenerative tauopathies, and transcellular propagation of tau assemblies of unique structure, i.e., strains, may underlie the diversity of these disorders. Polyanions have been reported to induce tau aggregation in vitro, but the precise trigger to convert tau from an inert to a seed-competent form in disease states is unknown. RNA triggers tau fibril formation in vitro and has been observed to associate with neurofibrillary tangles in human brain. Here, we have tested whether RNA exerts sequence-specific effects on tau assembly and strain formation. We found that three RNA homopolymers, polyA, polyU, and polyC, all bound tau, but only polyA RNA triggered seed and fibril formation. In addition, polyA:tau seeds and fibrils were sensitive to RNase. We also observed that the origin of the RNA influenced the ability of tau to adopt a structure that would form stable strains. Human RNA potently induced tau seed formation and created tau conformations that preferentially formed stable strains in a HEK293T cell model, whereas RNA from other sources, or heparin, produced strains that were not stably maintained in cultured cells. Finally, we found that soluble, but not insoluble seeds from Alzheimer's disease brain were also sensitive to RNase. We conclude that human RNA specifically induces formation of stable tau strains and may trigger the formation of dominant pathological assemblies that propagate in Alzheimer's disease and possibly other tauopathies.

Ameliorating Racial Disparities in Vascular Risk Factor Management With Aggressive Medical Management in the SAMMPRIS Trial.

BACKGROUND: The WASID trial (Warfarin-Aspirin Symptomatic Intracranial Disease) and the SAMMPRIS trial (Stenting and Aggressive Medical Management for Preventing Recurrent Stroke in Intracranial Stenosis) evaluated optimal management of symptomatic intracranial atherosclerotic stenosis. The aim of this retrospective, observational study was to determine whether aggressive medical management used in the SAMMPRIS trial ameliorated disparities in risk factor control between Black and non-Black patients. METHODS: The SAMMPRIS trial was a randomized controlled trial that enrolled patients with symptomatic intracranial atherosclerotic stenosis between November 2008 and April 2011. The frequency of risk factors at study entry (baseline) and mean levels of systolic blood pressure, diastolic blood pressure, LDL (low-density lipoprotein), hemoglobin A1c, and exercise level (quantified by physician-based assessment and counseling for exercise score) at baseline and at 1 year of follow-up were compared between Black (n=104) versus non-Black patients (n=347). RESULTS: Significant differences at baseline in Black patients (listed first) versus non-Black patients were age (57.5 versus 61.0 years; P=0.004), hypertension (95.2% versus 87.5%; P=0.027), diabetes (52.9% versus 39.7%; P=0.017), mean diastolic blood pressure (82.4 versus 79.5 mm Hg; P=0.035), and mean physician-based assessment and counseling for exercise score (2.7 versus 3.3; P=0.002). The mean diastolic blood pressure and mean physician-based assessment and counseling for exercise scores at 1 year in Black versus non-Black patients were 74.7 versus 75.5 mm Hg (P=0.575) and 4.2 versus 4.1 (P=0.593), respectively. No disparities in other modifiable risk factors emerged at 1 year. CONCLUSIONS: Significant differences in important risk factors (physical activity and diastolic blood pressure) at baseline between Black and non-Black patients resolved at 1 year, suggesting that aggressive medical management may have an important role in ameliorating disparities in risk factor control between Black and non-Black patients.

Adherence to Antiretrovirals and HIV Viral Suppression Under COVID-19 Pandemic Interruption - Findings from a Randomized Clinical Trial Using Ingestible Sensors to Monitor Adherence.

The COVID-19 pandemic had a significant impact on vulnerable populations, including people living with HIV. California implemented a coronavirus lockdown (stay-at-home order) in March 2020, which ended in January 2021. We evaluated the pandemic's impact on both clinical outcomes of HIV RNA viral load (VL) and retention rate in a randomized clinical trial conducted from May 2018 to October 2020. The intervention group took co-encapsulated antiretrovirals (ARVs) with ingestible sensor (IS) pills from baseline through week 16. The IS system has the capacity to monitor adherence in real-time using a sensor patch, a mobile device, and supporting software. Both the IS and usual care (UC) groups were followed monthly for 28 weeks. Longitudinal mixed-effects models with random intercept and slope (RIAS) were used to fit log VL and self-reported adherence. The sample size of the study was 112 (54 in IS). Overall, the retention rate at week 28 was 86%, with 90% before the lockdown and 83% after the lockdown. The lockdown strengthened the associations between adherence and VL. Before the lockdown, a 10% increase in adherence was associated with a 0.2 unit decrease in log VL (ß = -1.88, p = 0.004), while during the lockdown, the association was a 0.41-unit decrease (ß = -2.27, p = 0.03). The pandemic did not have a significant impact on our adherence-focused intervention. Our findings regarding the intervention effect remain valid. TRIAL REGISTRATION NUMBER: NCT02797262. Date registration: September 2015.

Synthetic applications of hydride abstraction reactions by organic oxidants.

Carbon-hydrogen bond functionalizations provide an attractive method for streamlining organic synthesis, and many strategies have been developed for conducting these transformations. Hydride-abstracting reactions have emerged as extremely effective methods for oxidative bond-forming processes due to their mild reaction conditions and high chemoselectivity. This review will predominantly focus on the mechanism, reaction development, natural product synthesis applications, approaches to catalysis, and use in enantioselective processes for hydride abstractions by quinone, oxoammonium ion, and carbocation oxidants. These are the most commonly employed hydride-abstracting agents, but recent efforts illustrate the potential for weaker ketone and triaryl borane oxidants, which will be covered at the end of the review.

Kinetics-Based Approach to Developing Electrocatalytic Variants of Slow Oxidations: Application to Hydride Abstraction-Initiated Cyclization Reactions.

Electrochemical oxidant regeneration is challenging in reactions that have a slow redox step because the steady-state concentration of the reduced oxidant is low, causing difficulties in maintaining sufficient current or preventing potential spikes. This work shows that applying an understanding of the relationship between intermediate cation stability, oxidant strength, overpotential, and concentration on reaction kinetics delivers a method for electrochemical oxoammonium ion regeneration in hydride abstraction-initiated cyclization reactions, resulting in the development of an electrocatalytic variant of a process that has a high oxidation transition state free energy. This approach should be applicable to expanding the scope of electrocatalysis to include additional slow redox processes.

Integrating Financial Coaching and Referrals into a Smoking Cessation Program for Low-income Smokers: a Randomized Waitlist Control Trial.

BACKGROUND: Financial distress is a barrier to cessation among low-income smokers. OBJECTIVE: To evaluate an intervention that integrated financial coaching and benefits referrals into a smoking cessation program for low-income smokers. DESIGN: Randomized waitlist control trial conducted from 2017 to 2019. PARTICIPANTS: Adult New York City residents were eligible if they reported past 30-day cigarette smoking, had income below 200% of the federal poverty level, spoke English or Spanish, and managed their own funds. Pregnant or breastfeeding people were excluded. Participants were recruited from two medical centers and from the community. INTERVENTION: The intervention (n = 208) offered smoking cessation coaching, nicotine replacement therapy, money management coaching, and referral to financial benefits and empowerment services. The waitlist control (n=202) was usual care during a 6-month waiting period. MAIN MEASURES: Treatment engagement, self-reported 7-day abstinence, and financial stress at 6 months. KEY RESULTS: At 6 months, intervention participants reported higher abstinence (17% vs. 9%, P=0.03), lower stress about finances (ß, -0.8 [SE, 0.4], P=0.02), and reduced frequency of being unable to afford activities (ß, -0.8 [SE, 0.4], P=0.04). Outcomes were stronger among participants recruited from the medical centers (versus from the community). Among medical center participants, the intervention was associated with higher abstinence (20% vs. 8%, P=0.01), higher satisfaction with present financial situation (ß, 1.0 [SE, 0.4], P=0.01), reduced frequency of being unable to afford activities (ß, -1.0 [SE, 0.5], P=0.04), reduced frequency in getting by paycheck-to-paycheck (ß, -1.0 [SE, 0.4], P=0.03), and lower stress about finances in general (ß, -1.0 [SE, 0.4], P = 0.02). There were no group differences in outcomes among people recruited from the community (P>0.05). CONCLUSIONS: Among low-income smokers recruited from medical centers, the intervention produced higher abstinence rates and reductions in some markers of financial distress than usual care. The intervention was not efficacious with people recruited from the community. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03187730.

Counseling Veterans with Chronic Pain During the COVID-19 Pandemic: A Secondary Analysis of a Randomized Controlled Trial.

INTRODUCTION: Veterans with chronic pain could be vulnerable during the COVID-19 pandemic. We qualitatively explored the impact of the COVID-19 pandemic on a sample of veterans receiving brief counseling focused on pain management in an ongoing clinical trial and discuss how the pandemic affected the process of motivating veterans with chronic pain to engage in interdisciplinary multimodal pain treatment at the Department of Veteran Affairs. METHODS: Segments of audio-recorded counseling sessions containing content about the pandemic were transcribed and coded to identify key concepts emerging from individual counselor-participant transactions. Themes that emerged were examined with constant comparison analysis. RESULTS: Three major themes emerged. 1) The pandemic caused a disruption in pain management service delivery, resulting in changes to the way veterans receive services or manage their pain symptoms. 2) The pandemic offered opportunities for resilience and personal growth as veterans with chronic pain reflected on their lives and personal goals. 3) The pandemic brought veterans' mental health issues to the forefront, and these should be addressed as part of a comprehensive pain management approach. DISCUSSION: Discussion of the COVID-19 pandemic during pain treatment counseling sessions highlighted negative and positive ways participants were affected by the pandemic. These discussions provided counselors with a unique opportunity to facilitate behavior change by focusing on characteristics of resilience to motivate individuals with chronic pain to adapt and adopt positive behaviors and outlooks to improve their pain experience and quality of life. CONCLUSIONS: Counselors can leverage feelings of resilience and personal growth to motivate veterans' use of adaptive coping skills and a wider array of pain management services.

Increasing buprenorphine access for veterans with opioid use disorder in rural clinics using telemedicine.

Background:Having prescribers use clinical video teleconferencing (telemedicine) to prescribe buprenorphine to people with opioid use disorder (OUD) has shown promise but its implementation is challenging. We describe barriers, facilitators and lessons learned while implementing a system to remotely prescribe buprenorphine to Veterans in rural settings. Methods: We conducted a quality improvement project aimed at increasing the availability of medications for OUD (MOUD) to Veterans. This project focused on tele-prescribing buprenorphine to rural sites via a hub (centralized prescribers) and spoke (rural clinics) model. After soliciting a wide-range of inputs from site visits, qualitative interviews of key stakeholders at rural sites, and review of preliminary cases, a "how-to" toolkit was developed and iteratively refined to guide tele-prescribing of buprenorphine. After internal and external facilitation strategies were employed, Veterans with OUD at three clinics were transitioned to buprenorphine treatment via telemedicine. Results: Factors impacting adoption of the tele-prescribing intervention were mapped to the Consolidated Framework for Implementation Research (CFIR) constructs. Barriers to adoption included concerns about legality of tele-prescribing a controlled substance, conflicting interests between different stakeholders, and coordination with an existing buprenorphine program requiring more attendance and abstinence from Veterans than the tele-prescribing program required. Factors facilitating adoption included a sense of mission around combating the opioid epidemic, preexisting use of and comfort with tele-prescribing, and rural sites' control over Veterans referred to tele-prescribers. A total of 12 patients from rural areas were successfully transitioned onto buprenorphine, of whom 9 remained on buprenorphine 6 months after initiation of treatment. Conclusions: Implementing tele-prescribing was negotiated with stakeholders at the target clinics and operationalized in a toolkit to guide future efforts. Implementation issues can be addressed by activities that foster collaboration between hubs (centralized prescribers) and spokes (rural clinics) and by a toolkit that operationalizes tele-prescribing procedures.

The acceptability and feasibility of screening, brief intervention, and referral to treatment for pain management among new England veterans with chronic pain: A pilot study.

OBJECTIVES: Musculoskeletal disorders often lead to chronic pain in Veterans. Chronic pain puts sufferers at risk for substance misuse, and early intervention is needed for both conditions. This pilot study tested the feasibility and acceptability of a Screening, Brief Intervention, and Referral to Treatment for Pain Management intervention (SBIRT-PM) to help engage Veterans seeking disability compensation for painful musculoskeletal disorders in multimodal pain treatment and to reduce risky substance use, when indicated. METHODS: This pilot study enrolled 40 Veterans from 8 medical centers across New England in up to 4 sessions of telephone-based counseling using a motivational interviewing framework. Counseling provided education about, and facilitated engagement in, multimodal pain treatments. Study eligibility required Veterans be engaged in no more than 2 Veteran Affairs (VA) pain treatment modalities, and study participation involved a 12-week postassessment and semistructured interview about the counseling process. RESULTS: Majorities of enrolled Veterans screened positive for comorbid depression and problematic substance use. Regarding the offered counseling, 80% of participants engaged in at least one session, with a mean of 3 sessions completed. Ninety percent of participants completed the postassessment. Numerically, most measures improved slightly from baseline to week 12. In semistructured interviews, participants described satisfaction with learning about new pain care services, obtaining assistance connecting to services, and receiving support from their counselors. DISCUSSION: It was feasible to deliver SBIRT-PM to Veterans across New England to promote engagement in multimodal pain treatment and to track study outcomes over 12 weeks. Preliminary results suggest SBIRT-PM was well-received and has promise for the targeted outcomes.

A synthetic heparinoid blocks Tau aggregate cell uptake and amplification.

Tau aggregation underlies neurodegeneration in Alzheimer's disease and related tauopathies. We and others have proposed that transcellular propagation of pathology is mediated by Tau prions, which are ordered protein assemblies that faithfully replicate in vivo and cause specific biological effects. The prion model predicts the release of aggregates from a first-order cell and subsequent uptake into a second-order cell. The assemblies then serve as templates for their own replication, a process termed "seeding." We have previously observed that heparan sulfate proteoglycans on the cell surface mediate the cellular uptake of Tau aggregates. This interaction is blocked by heparin, a sulfated glycosaminoglycan. Indeed, heparin-like molecules, or heparinoids, have previously been proposed as a treatment for PrP prion disorders. However, heparin is not ideal for managing chronic neurodegeneration, because it is difficult to synthesize in defined sizes, may have poor brain penetration because of its negative charge, and is a powerful anticoagulant. Therefore, we sought to generate an oligosaccharide that would bind Tau and block its cellular uptake and seeding, without exhibiting anticoagulation activity. We created a compound, SN7-13, from pentasaccharide units and tested it in a range of assays that measured direct binding of Tau to glycosaminoglycans and inhibition of Tau uptake and seeding in cells. SN7-13 does not inhibit coagulation, binds Tau with low nanomolar affinity, and inhibits cellular Tau aggregate propagation similarly to standard porcine heparin. This synthetic heparinoid could facilitate the development of agents to treat tauopathy.

Tau strains shape disease.

Tauopathies consist of over 25 different neurodegenerative diseases that include argyrophilic grain disease (AGD), progressive supranuclear palsy (PSP), corticobasal degeneration (CBD), and Pick's disease (PiD). Tauopathies are defined by brain accumulation of microtubule-associated protein tau in fibrillar aggregates, whose prevalence strongly correlates with dementia. Dominant mutations in tau cause neurodegenerative diseases, and most increase its aggregation propensity. Pathogenesis of tauopathies may involve pathological tau conformers that serve as templates to recruit native protein into growing assemblies and also move between brain cells to cause disease progression, similar to prions. Prions adopt pathological conformations, termed "strains," that stably propagate in living systems, and create unique patterns of neuropathology. Data from multiple laboratories now suggest that tau acts as a prion. It propagates unique strains indefinitely in cultured cells, and when these are inoculated into mouse models, they create defined neuropathological patterns, which establish a direct link between conformation and disease. In humans, distinct fibril structures are associated with different diseases, but causality has not been established as in mice. Cryo-EM structures of tau fibrils isolated from tauopathy brains reveal distinct fibril cores across disease. Interestingly, the conformation of the tau monomer unit within different fibril subtypes from the same patient appears relatively preserved. This is consistent with data that the tau monomer samples an ensemble of conformations that act as distinct pathologic templates in the formation of restricted numbers of strains. The propensity of a tau monomer to adopt distinct conformations appears to be linked to defined local motifs that expose different patterns of amyloidogenic amino acid sequences. The prion hypothesis, which predicts that protein structure dictates resultant disease, has proved particularly useful to understand the diversity of human tauopathies. The challenge now is to develop methods to rapidly classify patients according to the structure of the underlying pathological protein assemblies to achieve more accurate diagnosis and effective therapy.

Tau seeding in chronic traumatic encephalopathy parallels disease severity.

Chronic traumatic encephalopathy (CTE), a neurodegenerative tauopathy, is associated with behavioral, mood and cognitive impairment, including dementia. Tauopathies are neurodegenerative diseases whose neuropathological phenotypes are characterized by distinct histopathologic features of tau pathology, which progressively deposit throughout the brain. In certain tauopathies, especially Alzheimer's disease (AD), tau deposition appears to follow brain network connections. Experimental evidence suggests that the progression of tau pathology in humans, mouse and cell models could be explained by tau seeds that adopt distinct conformations and serve as templates for their own amplification to mediate transcellular propagation of pathology. Tau seeds are efficiently detected by the induction of aggregation in cell-based "biosensors" that express tau repeat domain (RD) with a disease-associated mutation (P301S) fused to complementary fluorescent protein tags (cyan and yellow fluorescent protein). Biosensors enable quantification of tau seeding in fixed and fresh-frozen brain tissue. Phospho-tau deposition in CTE follows progressive stages (I-IV), but the relationship of seeding to this deposition is unclear. We have used an established biosensor assay to independently quantify tau seeding as compared to AT8 phospho-tau histopathology in thin sections of fixed tissues of 11 brain regions from 27 patients with CTE, 5 with other tauopathies, and 5 negative controls. In contrast to prior studies of AD, we detected tau seeding late in the course of CTE (predominantly stages III and IV). It was less anatomically prevalent than AT8-positive inclusions, which were relatively widespread. We especially observed seeding in the limbic system (amygdala, thalamus, basal ganglia), which may explain the dominant cognitive and behavior impairments that characterize CTE.