Loss of sigma-2 receptor/TMEM97 is associated with neuropathic injury-induced depression-like behaviors in female mice.

Previous studies have shown that ligands that bind to sigma-2 receptor/TMEM97 (σ2R/TMEM97), a transmembrane protein, have anxiolytic/antidepressant-like properties and relieve neuropathic pain-like effects in rodents. Despite medical interest in σ2R/TMEM97, little affective and pain behavioral characterization has been done using transgenic mice, which limits the development of σ2R/TMEM97 as a viable therapeutic target. Using wild-type (WT) and global Tmem97 knockout (KO) mice, we sought to identify the contribution of Tmem97 in modulating affective and pain-like behaviors using a battery of affective and pain assays, including open field, light/dark preference, elevated plus maze, forced swim test, tail suspension test, and the mechanical sensitivity tests. Our results demonstrate that female Tmem97 KO mice show less anxiety-like and depressive-like behaviors in light/dark preference and tail suspension tests but not in an open field, elevated plus maze, and forced swim tests at baseline. We next performed spared nerve injury in WT and Tmem97 KO mice to assess the role of Tmem97 in neuropathic pain-induced anxiety and depression. WT mice, but not Tmem97 KO mice, developed a prolonged neuropathic pain-induced depressive-like phenotype when tested ten weeks after nerve injury in females. Our results show that Tmem97 plays a role in modulating anxiety-like and depressive-like behaviors in naïve animals with a significant change in the presence of nerve injury in female mice. Overall, these data demonstrate that Tmem97 could be a target to alleviate affective comorbidities of pain disorders.Significance Statement Chronic pain comorbidities, including anxiety and depression, present a significant public health challenge. Pharmacological agents developed to target the sigma-2 receptor/TMEM97 (σ2R/TMEM97) have demonstrated promising effects in alleviating anxiety, depression, and pain individually. Our work provides insight on the interaction between σ2R/TMEM97 and neuropathic pain-induced affective behaviors using transgenic mice, suggesting its potential as a novel therapeutic target for addressing both the pain and psychiatric components in complex chronic pain disorders.

Seasonal Variability in the Prevalence of DWV Strains in Individual Colonies of European Honeybees in Hawaii.

The most prevalent viral pathogen of honeybees is Deformed Wing Virus (DWV) and its two most widely studied and common master-variants are DWV-A and DWV-B. The prevalence of DWV variants in the UK and in the US is changing, with the prevalence of the DWV-A strain declining and DWV-B increasing over time. In 2012, only DWV-A was detected on the Hawaiian Islands of Oahu. In this study we focused on a colony-level survey of DWV strains in a single apiary and examined the prevalence of DWV variants over the course of two years. In 2018 and 2019, a total of 16 colonies underwent viral testing in January, May, and September. Of those 16 colonies, four were monitored in both 2018 and 2019. Individual colonies showed variability of DWV master variants throughout the sampling period. DWV-A was consistently detected; however, the detection of DWV-B was variable across time in individual colonies. Ultimately, this study demonstrated a seasonal variation in both viral prevalence and load for DWV-B, providing a perspective on the dynamic nature of DWV master variants emerging in Hawaii.

Neurosteroid Modulation of Synaptic and Extrasynaptic GABAA Receptors of the Mouse Nucleus Accumbens.

The recent approval of formulations of the endogenous neurosteroid allopregnanolone (brexanolone) and the synthetic neuroactive steroid SAGE-217 (zuranolone) to treat postpartum depression (PPD) has encouraged further research to elucidate why these potent enhancers of GABAAR function are clinically effective in this condition. Dopaminergic projections from the ventral tegmental area (VTA) to the nucleus accumbens are associated with reward/motivation and brain imaging studies report that individuals with PPD show reduced activity of this pathway in response to reward and infant engagement. However, the influence of neurosteroids on GABA-ergic transmission in the nucleus accumbens has received limited attention. Here, we investigate, in the medium spiny neurons (MSNs) of the mouse nucleus accumbens core, the effect of allopregnanolone, SAGE-217 and other endogenous and synthetic steroids of interest on fast phasic and tonic inhibition mediated by synaptic (α1/2ßγ2) and extrasynaptic (α4ßδ) GABAARs, respectively. We present evidence suggesting the resident tonic current results from the spontaneous opening of δ-GABAARs, where the steroid-enhanced tonic current is GABA-dependent. Furthermore, we demonstrate local neurosteroid synthesis in the accumbal slice preparation and reveal that GABA-ergic neurotransmission of MSNs is influenced by an endogenous neurosteroid tone. Given the dramatic fluctuations in allopregnanolone levels during pregnancy and postpartum, this neurosteroid-mediated local fine-tuning of GABAergic transmission in the MSNs will probably be perturbed.

Structure-Affinity relationships of novel σ2R/TMEM97 ligands.

The sigma 2 receptor (σ2R), which was recently identified as the transmembrane protein 97 (TMEM97), is increasingly attracting interest as a possible therapeutic target for indications in neuroscience. Toward identifying novel modulators of σ2R/TMEM97, we prepared a collection of benzoxazocine, benzomorphan, and methanobenzazepine ligands related to the known bioactive norbenzomorphans DKR-1677, FEM-1689, and EES-1686 and determined their Ki values for σ2R/TMEM97 and the sigma 1 receptor (σ1R). The σ2R/TMEM97 binding affinities and selectivities relative to σ1R of these new benzoxazocine, benzomorphan, and methanobenzazepine analogs are lower, often significantly lower, than their respective norbenzomorphan counterparts, suggesting the spatial orientation of pharmacophoric substituents is critical for binding to the two proteins. The benzoxazocine, benzomorphan, and methanobenzazepine congeners of DKR-1677 and FEM-1689 tend to be weakly selective for σ2R/TMEM97 versus σ1R, whereas EES-1686 derivatives exhibit the greatest selectivity, suggesting the size and/or nature of the substituent on the nitrogen atom of the scaffold may be important for selectivity. Computational docking studies were performed for the 1S,5R-and 1R,5S-enantiomers of DKR-1677, FEM-1689, and EES-1686 and their benzoxazocine, benzomorphan, and methanobenzazepine counterparts. These computations predict that the protonated amino group of each ligand forms a highly conserved salt bridge and a H-bonding interaction with Asp29 as well as a cation-π interaction with Tyr150 of σ2R/TMEM97. These electrostatic interactions are major driving forces for binding to σ2R/TMEM97 and are similar, though not identical, for each ligand. Other interactions within the well-defined binding pocket also tend to be comparable, but there are some major differences in how the hydrophobic aryl groups of various ligands interact with the protein surface external to the binding pocket. Overall, these studies show that the orientations of aryl and N-substituents on the norbenzomorphan and related scaffolds are important determinants of binding affinity of σ2R/TMEM97 ligands, and small changes can have significant effects upon binding profiles.

Rapamycin does not alter bone microarchitecture or material properties quality in young-adult and aged female C57BL/6 mice.

Advancing age is the strongest risk factor for osteoporosis and skeletal fragility. Rapamycin is an FDA-approved immunosuppressant that inhibits the mechanistic target of rapamycin (mTOR) complex, extends lifespan, and protects against aging-related diseases in multiple species; however, the impact of rapamycin on skeletal tissue is incompletely understood. We evaluated the effects of a short-term, low-dosage, interval rapamycin treatment on bone microarchitecture and strength in young-adult (3 mo old) and aged female (20 mo old) C57BL/6 mice. Rapamycin (2 mg/kg body mass) was administered via intraperitoneal injection 1×/5 d for a duration of 8 wk; this treatment regimen has been shown to induce geroprotective effects while minimizing the side effects associated with higher rapamycin dosages and/or more frequent or prolonged delivery schedules. Aged femurs exhibited lower cancellous bone mineral density, volume, trabecular connectivity density and number, higher trabecular thickness and spacing, and lower cortical thickness compared to young-adult mice. Rapamycin had no impact on assessed microCT parameters. Flexural testing of the femur revealed that both yield strength and ultimate strength were lower in aged mice compared to young-adult mice. There were no effects of rapamycin on these or other measures of bone biomechanics. Age, but not rapamycin, altered local and global measures of bone turnover. These data demonstrate that short-term, low-dosage interval rapamycin treatment does not negatively or positively impact the skeleton of young-adult and aged mice.

Atopic dermatitis (eczema) guidelines: 2023 American Academy of Allergy, Asthma and Immunology/American College of Allergy, Asthma and Immunology Joint Task Force on Practice Parameters GRADE- and Institute of Medicine-based recommendations.

BACKGROUND: Guidance addressing atopic dermatitis (AD) management, last issued in 2012 by the American Academy of Allergy, Asthma and Immunology/American College of Allergy, Asthma and Immunology Joint Task Force, requires updating as a result of new treatments and improved guideline and evidence synthesis methodology. OBJECTIVE: To produce evidence-based guidelines that support patients, clinicians, and other decision-makers in the optimal treatment of AD. METHODS: A multidisciplinary guideline panel consisting of patients and caregivers, AD experts (dermatology and allergy/immunology), primary care practitioners (family medicine, pediatrics, internal medicine), and allied health professionals (psychology, pharmacy, nursing) convened, prioritized equity, diversity, and inclusiveness, and implemented management strategies to minimize influence of conflicts of interest. The Evidence in Allergy Group supported guideline development by performing systematic evidence reviews, facilitating guideline processes, and holding focus groups with patient and family partners. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach informed rating the certainty of evidence and strength of recommendations. Evidence-to-decision frameworks, subjected to public comment, translated evidence to recommendations using trustworthy guideline principles. RESULTS: The panel agreed on 25 recommendations to gain and maintain control of AD for patients with mild, moderate, and severe AD. The eAppendix provides practical information and implementation considerations in 1-2 page patient-friendly handouts. CONCLUSION: These evidence-based recommendations address optimal use of (1) topical treatments (barrier moisturization devices, corticosteroids, calcineurin inhibitors, PDE4 inhibitors [crisaborole], topical JAK inhibitors, occlusive [wet wrap] therapy, adjunctive antimicrobials, application frequency, maintenance therapy), (2) dilute bleach baths, (3) dietary avoidance/elimination, (4) allergen immunotherapy, and (5) systemic treatments (biologics/monoclonal antibodies, small molecule immunosuppressants [cyclosporine, methotrexate, azathioprine, mycophenolate, JAK inhibitors], and systemic corticosteroids) and UV phototherapy (light therapy).

Highly specific σ2R/TMEM97 ligand FEM-1689 alleviates neuropathic pain and inhibits the integrated stress response.

The sigma 2 receptor (σ2R) was described pharmacologically more than three decades ago, but its molecular identity remained obscure until recently when it was identified as transmembrane protein 97 (TMEM97). We and others have shown that σ2R/TMEM97 ligands alleviate mechanical hypersensitivity in mouse neuropathic pain models with a time course wherein maximal antinociceptive effect is approximately 24 h following dosing. We sought to understand this unique antineuropathic pain effect by addressing two key questions: do these σ2R/TMEM97 compounds act selectively via the receptor, and what is their downstream mechanism on nociceptive neurons? Using male and female conventional knockout mice for Tmem97, we find that a σ2R/TMEM97 binding compound, FEM-1689, requires the presence of the gene to produce antinociception in the spared nerve injury model in mice. Using primary mouse dorsal root ganglion neurons, we demonstrate that FEM-1689 inhibits the integrated stress response (ISR) and promotes neurite outgrowth via a σ2R/TMEM97-specific action. We extend the clinical translational value of these findings by showing that FEM-1689 reduces ISR and p-eIF2α levels in human sensory neurons and that it alleviates the pathogenic engagement of ISR by methylglyoxal. We also demonstrate that σ2R/TMEM97 is expressed in human nociceptors and satellite glial cells. These results validate σ2R/TMEM97 as a promising target for further development for the treatment of neuropathic pain.

Cell-type-specific optogenetic stimulation of the locus coeruleus induces slow-onset potentiation and enhances everyday memory in rats.

Memory formation is typically divided into phases associated with encoding, storage, consolidation, and retrieval. The neural determinants of these phases are thought to differ. This study first investigated the impact of the experience of novelty in rats incurred at a different time, before or after, the precise moment of memory encoding. Memory retention was enhanced. Optogenetic activation of the locus coeruleus mimicked this enhancement induced by novelty, both when given before and after the moment of encoding. Optogenetic activation of the locus coeruleus also induced a slow-onset potentiation of field potentials in area CA1 of the hippocampus evoked by CA3 stimulation. Despite the locus coeruleus being considered a primarily noradrenergic area, both effects of such stimulation were blocked by the dopamine D1/D5 receptor antagonist SCH 23390. These findings substantiate and enrich the evidence implicating the locus coeruleus in cellular aspects of memory consolidation in hippocampus.

Evidence on Buprenorphine Dose Limits: A Review.

OBJECTIVES: As overdose deaths from fentanyl continue to increase, optimizing use of medications for opioid use disorder has become increasingly important. Buprenorphine is a highly effective medication for reducing the risk of overdose death, but only if a patient remains in treatment. Shared decision making between prescribers and patients is important to establish a dose that meets each patient's treatment needs. However, patients frequently face a dose limit of 16 or 24 mg/d based on dosing guidelines on the Food and Drug Administration's package label. METHODS: This review discusses patient-centered goals and clinical criteria for determining dose adequacy, reviews the history of buprenorphine dose regulation in the United States, examines pharmacological and clinical research results with buprenorphine doses up to 32 mg/d, and evaluates whether diversion concerns justify maintaining a low buprenorphine dose limit. RESULTS: Pharmacological and clinical research results consistently demonstrate buprenorphine's dose-dependent benefits up to at least 32 mg/d, including reductions in withdrawal symptoms, craving, opioid reward, and illicit use while improving retention in care. Diverted buprenorphine is most often used to treat withdrawal symptoms and reduce illicit opioid use when legal access to it is limited. CONCLUSIONS: In light of established research and profound harms from fentanyl, the Food and Drug Administration's current recommendations on target dose and dose limit are outdated and causing harm. An update to the buprenorphine package label with recommended dosing up to 32 mg/d and elimination of the 16 mg/d target dose would improve treatment effectiveness and save lives.

Dopamine D1-like receptors modulate synchronized oscillations in the hippocampal-prefrontal-amygdala circuit in contextual fear.

Contextual fear conditioning (CFC) is mediated by a neural circuit that includes the hippocampus, prefrontal cortex, and amygdala, but the neurophysiological mechanisms underlying the regulation of CFC by neuromodulators remain unclear. Dopamine D1-like receptors (D1Rs) in this circuit regulate CFC and local synaptic plasticity, which is facilitated by synchronized oscillations between these areas. In rats, we determined the effects of systemic D1R blockade on CFC and oscillatory synchrony between dorsal hippocampus (DH), prelimbic (PL) cortex, basolateral amygdala (BLA), and ventral hippocampus (VH), which sends hippocampal projections to PL and BLA. D1R blockade altered DH-VH and reduced VH-PL and VH-BLA synchrony during CFC, as inferred from theta and gamma coherence and theta-gamma coupling. D1R blockade also impaired CFC, as indicated by decreased freezing at retrieval, which was characterized by altered DH-VH and reduced VH-PL, VH-BLA, and PL-BLA synchrony. This reduction in VH-PL-BLA synchrony was not fully accounted for by non-specific locomotor effects, as revealed by comparing between epochs of movement and freezing in the controls. These results suggest that D1Rs regulate CFC by modulating synchronized oscillations within the hippocampus-prefrontal-amygdala circuit. They also add to growing evidence indicating that this circuit synchrony at retrieval reflects a neural signature of learned fear.

Topical treatments for atopic dermatitis (eczema): Systematic review and network meta-analysis of randomized trials.

BACKGROUND: Atopic dermatitis (AD) is a common skin condition with multiple topical treatment options, but uncertain comparative effects. OBJECTIVE: We sought to systematically synthesize the benefits and harms of AD prescription topical treatments. METHODS: For the 2023 American Academy of Allergy, Asthma & Immunology and American College of Allergy, Asthma, and Immunology Joint Task Force on Practice Parameters AD guidelines, we searched MEDLINE, EMBASE, CENTRAL, CINAHL, LILACS, ICTRP, and GREAT databases to September 5, 2022, for randomized trials addressing AD topical treatments. Paired reviewers independently screened records, extracted data, and assessed risk of bias. Random-effects network meta-analyses addressed AD severity, itch, sleep, AD-related quality of life, flares, and harms. The Grading of Recommendations Assessment, Development and Evaluation approach informed certainty of evidence ratings. We classified topical corticosteroids (TCS) using 7 groups-group 1 being most potent. This review is registered in the Open Science Framework (https://osf.io/q5m6s). RESULTS: The 219 included trials (43,123 patients) evaluated 68 interventions. With high-certainty evidence, pimecrolimus improved 6 of 7 outcomes-among the best for 2; high-dose tacrolimus (0.1%) improved 5-among the best for 2; low-dose tacrolimus (0.03%) improved 5-among the best for 1. With moderate- to high-certainty evidence, group 5 TCS improved 6-among the best for 3; group 4 TCS and delgocitinib improved 4-among the best for 2; ruxolitinib improved 4-among the best for 1; group 1 TCS improved 3-among the best for 2. These interventions did not increase harm. Crisaborole and difamilast were intermediately effective, but with uncertain harm. Topical antibiotics alone or in combination may be among the least effective. To maintain AD control, group 5 TCS were among the most effective, followed by tacrolimus and pimecrolimus. CONCLUSIONS: For individuals with AD, pimecrolimus, tacrolimus, and moderate-potency TCS are among the most effective in improving and maintaining multiple AD outcomes. Topical antibiotics may be among the least effective.

Systemic treatments for atopic dermatitis (eczema): Systematic review and network meta-analysis of randomized trials.

BACKGROUND: Atopic dermatitis (AD) is an inflammatory skin condition with multiple systemic treatments and uncertainty regarding their comparative impact on AD outcomes. OBJECTIVE: We sought to systematically synthesize the benefits and harms of AD systemic treatments. METHODS: For the 2023 American Academy of Allergy, Asthma & Immunology and American College of Allergy, Asthma, and Immunology Joint Task Force on Practice Parameters AD guidelines, we searched MEDLINE, EMBASE, CENTRAL, Web of Science, and GREAT databases from inception to November 29, 2022, for randomized trials addressing systemic treatments and phototherapy for AD. Paired reviewers independently screened records, extracted data, and assessed risk of bias. Random-effects network meta-analyses addressed AD severity, itch, sleep, AD-related quality of life, flares, and harms. The Grading of Recommendations Assessment, Development and Evaluation approach informed certainty of evidence ratings. This review is registered in the Open Science Framework (https://osf.io/e5sna). RESULTS: The 149 included trials (28,686 patients with moderate-to-severe AD) evaluated 75 interventions. With high-certainty evidence, high-dose upadacitinib was among the most effective for 5 of 6 patient-important outcomes; high-dose abrocitinib and low-dose upadacitinib were among the most effective for 2 outcomes. These Janus kinase inhibitors were among the most harmful in increasing adverse events. With high-certainty evidence, dupilumab, lebrikizumab, and tralokinumab were of intermediate effectiveness and among the safest, modestly increasing conjunctivitis. Low-dose baricitinib was among the least effective. Efficacy and safety of azathioprine, oral corticosteroids, cyclosporine, methotrexate, mycophenolate, phototherapy, and many novel agents are less certain. CONCLUSIONS: Among individuals with moderate-to-severe AD, high-certainty evidence demonstrates that high-dose upadacitinib is among the most effective in addressing multiple patient-important outcomes, but also is among the most harmful. High-dose abrocitinib and low-dose upadacitinib are effective, but also among the most harmful. Dupilumab, lebrikizumab, and tralokinumab are of intermediate effectiveness and have favorable safety.

Is extending eligibility for adult social care better than investing more in existing users in England? A cross-sectional evidence for multiple financial years.

OBJECTIVES: Publicly funded adult social care (ASC) in England aims to improve quality of life through the provision of services for individuals with care needs due to physical and/or mental impairment or illness. Access to these services, however, is often restricted to contain public expenditure. With a fast-growing care need, information on whether extending eligibility is good value for money becomes policy-relevant. PRIMARY AND SECONDARY OUTCOME MEASURES: This study investigates the effect of extending ASC eligibility on user care-related quality of life (CRQoL), a policy-relevant measure of quality of life. DESIGN: We use English cross-sectional survey data from 2017/2018 to 2019/2020 on users receiving publicly funded long-term support including domiciliary and other community-based social care, as well as residential and nursing care from local authorities responsible for ASC. We employ the two-stage least square method to estimate the impact of ASC expenditure on CRQoL at various levels of ASC expenditure in each financial year. This includes the CRQoL effect of increasing expenditure from zero to some level, which captures the effect of extending ASC eligibility to new users. RESULTS: We find that publicly funded ASC improves the CRQoL of both existing and newly eligible users, although the latter are likely to experience greater CRQoL gains. Moreover, from 2017/2018 to 2019/2020, spending as much as an average user for a newly eligible user costs between £54 224 and £77 778 per social care-quality-adjusted life year (SC-QALY) gained. These results are statistically significant at the 5% level. Compared with this finding, increasing expenditure for an existing user has always a higher cost per SC-QALY gained. CONCLUSIONS: Extending ASC eligibility to new users is likely to be more cost-effective compared with using the same resources to increase expenditure for existing users.

Flow induced attrition of cellulose nanocrystals.

To study the potential impacts of shear stress on cellulose nanocrystals (CNCs), a microcapillary rheometer was employed to repeatedly shear approximately 10 mL of 6 wt% aqueous CNC suspension at 25 °C and rates ranging from 1,000 s-1 to 501,000 s-1. A 9 wt% CNC suspension was also tested at 316,000 s-1 for comparison of concentration effects on the behavior of the suspensions. After monitoring viscosity for 25 steady shear measurements, the suspensions processed at 1,000 s-1 decreased in viscosity by approximately 20 %. Higher shear rates produced smaller changes in viscosity, while increasing the concentration produced higher general viscosities. Atomic force microscopy (AFM) and X-ray diffraction (XRD) probed physical changes between the neat and sheared CNC samples. AFM images showed up to a 24 % reduction in length after shearing, but an insignificant reduction in cross-section. XRD showed a slight increase in the ratio of amorphous to crystalline fractions of the CNCs. Additionally, conductometric titration showed insignificant differences between neat and sheared samples. These findings suggest that viscosity changes in CNC suspensions during steady shear flow arise from physical fracturing of the CNCs perpendicular to their length, and not significantly from chemical degradation or reduction in residual amorphous content.

Clinic-based interventions to increase preexposure prophylaxis awareness and uptake among United States patients attending an obstetrics and gynecology clinic in Baltimore, Maryland.

BACKGROUND: Cisgender women account for 1 of every 5 new US HIV diagnoses, with most cases (85%) attributed to heterosexual contact. HIV preexposure prophylaxis is an effective prevention strategy; however, preexposure prophylaxis awareness and prescriptions among women are low. OBJECTIVE: This study aimed to increase preexposure prophylaxis counseling and uptake among cisgender women attending obstetrics and gynecology clinics. STUDY DESIGN: The study included 3 obstetrics and gynecology clinics within a single health system in a high HIV prevalence region. There were 3 phases: baseline (the 3-month period before the clinical trial that included provider education and training of a registered nurse about preexposure prophylaxis), clinical trial (the 3-month period during which eligible patients were randomized to an active control or preexposure prophylaxis registered nurse intervention), and maintenance (the 3-month period after the trial ended). Electronic medical record clinical decision support tools were available to both arms during the clinical trial, which included best practice alerts, order sets, progress note templates, and written and video preexposure prophylaxis educational materials for patients. In the intervention arm, a preexposure prophylaxis nurse contacted and counseled patients and was equipped to prescribe preexposure prophylaxis. Moreover, this study evaluated the phases through the "reach, effectiveness, adoption, implementation, and maintenance" framework. The primary outcome of the study was effectiveness (eg, percentage of eligible patients with documented HIV prevention counseling in the electronic medical record or preexposure prophylaxis prescriptions). The secondary outcomes included reach (eg, percentage of best practice alerts that providers acted on or the percentage of eligible patients who spoke with the preexposure prophylaxis registered nurse), adoption (eg, percentage of eligible patients with a best practice alert that triggered or the percentage of eligible patients the preexposure prophylaxis registered nurse attempted to contact), and maintenance (eg, percentage of patients with documented HIV prevention counseling or preexposure prophylaxis prescriptions during the maintenance phase). RESULTS: There were 904 unique patients in all phases with a mean age of 28.8±7.7 years, and 416 patients (46%) were pregnant; moreover, 436 patients were randomized in the clinical trial phase. Concerning reach and adoption, best practice alerts were triggered for 100% of eligible encounters; however, the providers acted on 52% of them. The preexposure prophylaxis nurse attempted to contact every patient and successfully spoke with 81.2% of them in the preexposure prophylaxis registered nurse arm. Concerning effectiveness, there were significantly more patients counseled about preexposure prophylaxis in the preexposure prophylaxis registered nurse group than in the active control group (66.5% vs 12.3%, respectively; P<.001), although preexposure prophylaxis prescriptions were equivalent (P=1.0). Among the subgroup of patients who were counseled about preexposure prophylaxis, 18.5% of patients in the active control arm and 3.4% in the preexposure prophylaxis registered nurse arm were prescribed preexposure prophylaxis (P=.02). Concerning maintenance, clinical decision support tools alone resulted in preexposure prophylaxis counseling of 1.0% of patients during the maintenance phase vs 0.6% of patients during the baseline phase and 11.2% of patients during the clinical trial phase (P<.001). Preexposure prophylaxis prescriptions were not statistically different among the 3 phases (P=.096). CONCLUSION: A preexposure prophylaxis nurse effectively increased HIV prevention discussions but did not lead to more preexposure prophylaxis prescriptions than the preexposure prophylaxis-focused clinical decision support tools used by providers. The decrease in preexposure prophylaxis counseling after the trial phase suggests that persistent interventions are needed to maintain effects.

Transcriptome-wide RNA binding analysis of C9orf72 poly(PR) dipeptides.

An intronic GGGGCC repeat expansion in C9orf72 is a common genetic cause of amyotrophic lateral sclerosis and frontotemporal dementia. The repeats are transcribed in both sense and antisense directions to generate distinct dipeptide repeat proteins, of which poly(GA), poly(GR), and poly(PR) have been implicated in contributing to neurodegeneration. Poly(PR) binding to RNA may contribute to toxicity, but analysis of poly(PR)-RNA binding on a transcriptome-wide scale has not yet been carried out. We therefore performed crosslinking and immunoprecipitation (CLIP) analysis in human cells to identify the RNA binding sites of poly(PR). We found that poly(PR) binds to nearly 600 RNAs, with the sequence GAAGA enriched at the binding sites. In vitro experiments showed that poly(GAAGA) RNA binds poly(PR) with higher affinity than control RNA and induces the phase separation of poly(PR) into condensates. These data indicate that poly(PR) preferentially binds to poly(GAAGA)-containing RNAs, which may have physiological consequences.

TMEM106B is a receptor mediating ACE2-independent SARS-CoV-2 cell entry.

SARS-CoV-2 is associated with broad tissue tropism, a characteristic often determined by the availability of entry receptors on host cells. Here, we show that TMEM106B, a lysosomal transmembrane protein, can serve as an alternative receptor for SARS-CoV-2 entry into angiotensin-converting enzyme 2 (ACE2)-negative cells. Spike substitution E484D increased TMEM106B binding, thereby enhancing TMEM106B-mediated entry. TMEM106B-specific monoclonal antibodies blocked SARS-CoV-2 infection, demonstrating a role of TMEM106B in viral entry. Using X-ray crystallography, cryogenic electron microscopy (cryo-EM), and hydrogen-deuterium exchange mass spectrometry (HDX-MS), we show that the luminal domain (LD) of TMEM106B engages the receptor-binding motif of SARS-CoV-2 spike. Finally, we show that TMEM106B promotes spike-mediated syncytium formation, suggesting a role of TMEM106B in viral fusion. Together, our findings identify an ACE2-independent SARS-CoV-2 infection mechanism that involves cooperative interactions with the receptors heparan sulfate and TMEM106B.

Correction: Vector mapping and bloodmeal metabarcoding demonstrate risk of urban Chagas disease transmission in Caracas, Venezuela.

[This corrects the article DOI: 10.1371/journal.pntd.0010613.].

Direct m6A recognition by IMP1 underlays an alternative model of target selection for non-canonical methyl-readers.

m6A methylation provides an essential layer of regulation in organismal development, and is aberrant in a range of cancers and neuro-pathologies. The information encoded by m6A methylation is integrated into existing RNA regulatory networks by RNA binding proteins that recognise methylated sites, the m6A readers. m6A readers include a well-characterised class of dedicated proteins, the YTH proteins, as well as a broader group of multi-functional regulators where recognition of m6A is only partially understood. Molecular insight in this recognition is essential to build a mechanistic understanding of global m6A regulation. In this study, we show that the reader IMP1 recognises the m6A using a dedicated hydrophobic platform that assembles on the methyl moiety, creating a stable high-affinity interaction. This recognition is conserved across evolution and independent from the underlying sequence context but is layered upon the strong sequence specificity of IMP1 for GGAC RNA. This leads us to propose a concept for m6A regulation where methylation plays a context-dependent role in the recognition of selected IMP1 targets that is dependent on the cellular concentration of available IMP1, differing from that observed for the YTH proteins.