Stealing VEGF from thy neighbor.

The distribution and patterning of blood vessels is controlled by vascular endothelial growth factor (VEGF), which is precisely regulated throughout its life cycle. Okabe et al. show that VEGF is titrated away from the endothelium by adjacent neurons via endocytosis, regulating density and trajectory of blood vessels.

Progesterone receptor in the vascular endothelium triggers physiological uterine permeability preimplantation.

Vascular permeability is frequently associated with inflammation and is triggered by a cohort of secreted permeability factors such as vascular endothelial growth factor (VEGF). Here, we show that the physiological vascular permeability that precedes implantation is directly controlled by progesterone receptor (PR) and is independent of VEGF. Global or endothelial-specific deletion of PR blocks physiological vascular permeability in the uterus, whereas misexpression of PR in the endothelium of other organs results in ectopic vascular leakage. Integration of an endothelial genome-wide transcriptional profile with chromatin immunoprecipitation sequencing revealed that PR induces an NR4A1 (Nur77/TR3)-dependent transcriptional program that broadly regulates vascular permeability in response to progesterone. Silencing of NR4A1 blocks PR-mediated permeability responses, indicating a direct link between PR and NR4A1. This program triggers concurrent suppression of several junctional proteins and leads to an effective, timely, and venous-specific regulation of vascular barrier function that is critical for embryo implantation.

The PilT retraction ATPase promotes both extension and retraction of the MSHA type IVa pilus in Vibrio cholerae.

Diverse bacterial species use type IVa pili (T4aP) to interact with their environments. The dynamic extension and retraction of T4aP is critical for their function, but the mechanisms that regulate this dynamic activity remain poorly understood. T4aP are typically extended via the activity of a dedicated extension motor ATPase and retracted via the action of an antagonistic retraction motor ATPase called PilT. These motors are generally functionally independent, and loss of PilT commonly results in T4aP hyperpiliation due to undeterred pilus extension. However, for the mannose-sensitive hemagglutinin (MSHA) T4aP of Vibrio cholerae, the loss of PilT unexpectedly results in a loss of surface piliation. Here, we employ a combination of genetic and cell biological approaches to dissect the underlying mechanism. Our results demonstrate that PilT is necessary for MSHA pilus extension in addition to its well-established role in promoting MSHA pilus retraction. Through a suppressor screen, we also provide genetic evidence that the MshA major pilin impacts pilus extension. Together, these findings contribute to our understanding of the factors that regulate pilus extension and describe a previously uncharacterized function for the PilT motor ATPase.

Dicer loss and recovery induce an oncogenic switch driven by transcriptional activation of the oncofetal Imp1-3 family.

MicroRNAs (miRNAs) are post-transcriptional regulators of gene expression critical for organismal viability. Changes in miRNA activity are common in cancer, but how these changes relate to subsequent alterations in transcription and the process of tumorigenesis is not well understood. Here, we report a deep transcriptional, oncogenic network regulated by miRNAs. We present analysis of the gene expression and phenotypic changes associated with global miRNA restoration in miRNA-deficient fibroblasts. This analysis uncovers a miRNA-repressed network containing oncofetal genes Imp1, Imp2, and Imp3 (Imp1-3) that is up-regulated primarily transcriptionally >100-fold upon Dicer loss and is resistant to resilencing by complete restoration of miRNA activity. This Dicer-resistant epigenetic switch confers tumorigenicity to these cells. Let-7 targets Imp1-3 are required for this tumorigenicity and feed back to reinforce and sustain expression of the oncogenic network. Together, these Dicer-resistant genes constitute an mRNA expression signature that is present in numerous human cancers and is associated with poor survival.

Cross-Platform Synaptic Network Analysis of Human Entorhinal Cortex Identifies TWF2 as a Modulator of Dendritic Spine Length.

Proteomic studies using postmortem human brain tissue samples have yielded robust assessments of the aging and neurodegenerative disease(s) proteomes. While these analyses provide lists of molecular alterations in human conditions, like Alzheimer's disease (AD), identifying individual proteins that affect biological processes remains a challenge. To complicate matters, protein targets may be highly understudied and have limited information on their function. To address these hurdles, we sought to establish a blueprint to aid selection and functional validation of targets from proteomic datasets. A cross-platform pipeline was engineered to focus on synaptic processes in the entorhinal cortex (EC) of human patients, including controls, preclinical AD, and AD cases. Label-free quantification mass spectrometry (MS) data (n = 2260 proteins) was generated on synaptosome fractionated tissue from Brodmann area 28 (BA28; n = 58 samples). In parallel, dendritic spine density and morphology was measured in the same individuals. Weighted gene co-expression network analysis was used to construct a network of protein co-expression modules that were correlated with dendritic spine metrics. Module-trait correlations were used to guide unbiased selection of Twinfilin-2 (TWF2), which was the top hub protein of a module that positively correlated with thin spine length. Using CRISPR-dCas9 activation strategies, we demonstrated that boosting endogenous TWF2 protein levels in primary hippocampal neurons increased thin spine length, thus providing experimental validation for the human network analysis. Collectively, this study describes alterations in dendritic spine density and morphology as well as synaptic proteins and phosphorylated tau from the entorhinal cortex of preclinical and advanced stage AD patients.SIGNIFICANCE STATEMENT Proteomic studies can yield vast lists of molecules that are altered under various experimental or disease conditions. Here, we provide a blueprint to facilitate mechanistic validation of protein targets from human brain proteomic datasets. We conducted a proteomic analysis of human entorhinal cortex (EC) samples spanning cognitively normal and Alzheimer's disease (AD) cases with a comparison of dendritic spine morphology in the same samples. Network integration of proteomics with dendritic spine measurements allowed for unbiased discovery of Twinfilin-2 (TWF2) as a regulator of dendritic spine length. A proof-of-concept experiment in cultured neurons demonstrated that altering Twinfilin-2 protein level induced corresponding changes in dendritic spine length, thus providing experimental validation for the computational framework.

Life satisfaction for adolescents with developmental and behavioral disabilities during the COVID-19 pandemic.

BACKGROUND: This study aimed to identify contextual factors associated with life satisfaction during the COVID-19 pandemic for adolescents with mental, emotional, behavioral, and developmental (MEBD) disabilities. METHODS: Data were collected from a sample of 1084 adolescents aged 11-21 years from April 2020 to August 2021. This cross-sectional study used a sequential machine learning workflow, consisting of random forest regression and evolutionary tree regression, to identify subgroups of adolescents in the Environmental influences on Child Health Outcomes (ECHO) consortium who demonstrated enhanced vulnerability to lower life satisfaction as described by intersecting risk factors, protective factors, and MEBD disabilities. RESULTS: Adolescents with a history of depression, anxiety, autism, and attention-deficit/hyperactivity disorder were particularly susceptible to decreased life satisfaction in response to unique combinations of stressors experienced during the COVID-19 pandemic. These stressors included decreased social connectedness, decreased family engagement, stress related to medical care access, pandemic-related traumatic stress, and single-caregiver households. CONCLUSION: Findings from this study highlight the importance of interventions aimed specifically at increasing adolescent social connectedness, family engagement, and access to medical support for adolescents with MEBD disabilities, particularly in the face of stressors, such as a global pandemic. IMPACT: Through a machine learning process, we identified contextualized risks associated with life satisfaction among adolescents with neurodevelopmental disabilities during the COVID-19 pandemic. The COVID-19 pandemic resulted in large-scale social disruptions for children and families. Such disruptions were associated with worse mental health outcomes in the general pediatric population, but few studies have examined specific subgroups who may be at heightened risk. We endeavored to close that gap in knowledge. This study highlights the importance of social connectedness, family engagement, and access to medical support as contributing factors to life satisfaction during the COVID-19 pandemic for adolescents with neurodevelopmental disabilities.

Association between maternal stress and child sleep quality: a nationwide ECHO prospective cohort study.

BACKGROUND: Childhood sleep quality is associated with physical, cognitive, and behavioral health and predicts later sleep quality; it has many determinants, including developmental exposures. OBJECTIVES: To examine associations between maternal stress during pregnancy and childhood sleep quality and determine whether postnatal stress mediates the association. METHOD: Data from the Environmental Influences on Child Health Outcomes cohort were used. Perceived Stress Scale (PSS) T-scores were the exposure measure. Outcome measures were preschool Child Behavior Checklist (CBCL) sleep syndrome scale and Patient-Reported Outcomes Measurement Information System Sleep Disturbance Parent Proxy short form 4a (PSD4a) T-scores at ages 4-8 years. Linear mixed-effects regression modeling was performed for each sleep outcome, adjusting for maternal age at delivery and education and child sex, gestational age at birth, and age at outcome ascertainment, with random intercepts for cohorts. RESULTS: Prenatal PSS score was associated with both CBCL (B = 0.09, 95% confidence interval [CI]: 0.06, 0.11; p < 0.01) and PSD4a (B = 0.07, 95% CI: 0.03, 0.12; p < 0.01) scores. Postnatal perceived stress mediated a proportion of the total effect of prenatal stress in both CBCL (66.3%) and PSD4a (95.9%) samples. CONCLUSIONS: Both pre- and postnatal maternal perceived stress appear to influence sleep quality during early life. IMPACT: Prenatal stress significantly associates with child sleep problems and disturbances at ages 4-8 years; postnatal maternal stress is a significant mediator of these associations. Research suggests a range of prenatal affective/distress exposures associated with child sleep problems, but the conclusions remain in doubt due to the mixture of exposures and outcomes employed. Ours is the first US-based effort to explore associations between perceived maternal stress during pregnancy and child sleep problems and disturbance in early and middle childhood. Even a small effect of a prevalent issue like psychosocial stress may have important public health implications at the population level.

Associations between neighborhood characteristics and child well-being before and during the COVID-19 pandemic: A repeated cross-sectional study in the Environmental influences on Child Health Outcomes (ECHO) program.

The corona virus disease (COVID-19) pandemic disrupted daily life worldwide, and its impact on child well-being remains a major concern. Neighborhood characteristics affect child well-being, but how these associations were affected by the pandemic is not well understood. We analyzed data from 1039 children enrolled in the Environmental influences on Child Health Outcomes Program whose well-being was assessed using the Patient-Reported Outcomes Measurement Information System Global Health questionnaire and linked these data to American Community Survey (ACS) data to evaluate the impacts of neighborhood characteristics on child well-being before and during the pandemic. We estimated the associations between more than 400 ACS variables and child well-being t-scores stratified by race/ethnicity (non-Hispanic white vs. all other races and ethnicities) and the timing of outcome data assessment (pre-vs. during the pandemic). Network graphs were used to visualize the associations between ACS variables and child well-being t-scores. The number of ACS variables associated with well-being t-scores decreased during the pandemic period. Comparing non-Hispanic white with other racial/ethnic groups during the pandemic, different ACS variables were associated with child well-being. Multiple ACS variables representing census tract-level housing conditions and neighborhood racial composition were associated with lower well-being t-scores among non-Hispanic white children during the pandemic, while higher percentage of Hispanic residents and higher percentage of adults working as essential workers in census tracts were associated with lower well-being t-scores among non-white children during the same study period. Our study provides insights into the associations between neighborhood characteristics and child well-being, and how the COVID-19 pandemic affected this relationship.

Assessing the interchangeability of linked scores in multivariable statistical analyses.

PURPOSE: Using the lens of classical test theory, we examine a linkage's generalizability with respect to use in multivariable analyses, including multiple regression and structural equation modeling, rather than comparison of established subpopulations as is most common in the literature. METHODS: To aid in this evaluation, we present a structural-equation-modeling based statistical method to examine the suitability of a given linkage for use cases involving continuous and categorical variables external to the linkage itself. RESULTS: Using the PROMIS® Parent Proxy and Early Childhood Global Health measures, we show that, although a high correlation between the scores (here, r = .829) may imply a general suitability for linking, a more detailed investigation of content, measurement structure, and results of the proposed methodology reveal important differences between the measures which can compromise interchangeability in certain use cases. CONCLUSION: In addition to the statistical quality of a linkage, users of linking methodology should also assess the question of whether the linkage is appropriate to apply to particular use cases of interest.

Narrative therapy and family therapy in genetic counseling: A scoping review.

Genetic counseling facilitates psychological and social adaptation in clients and families. Two psychotherapeutic approaches, narrative and family therapy foster client adaptation to adverse situations and may enhance the genetic counseling process. This scoping review aimed to describe the applications of narrative therapy and family therapy in genetic counseling, and to document the actual and perceived value of these approaches in a genetic counseling setting. Nine original research articles and six commentary articles met the study inclusion criteria. Original articles reported on positive client attitudes when these approaches were applied to hereditary cancer and Huntington disease settings. Five studies applied either approach in group sessions, where safety was key to positive outcomes, including sharing lived experiences and coping strategies. Balanced utilization of structured and open elements in group sessions maximized a sense of control, while also allowing for opportunity to self-disclose. Narrative therapy interventions were time efficient and were reported to foster connection with others and shape a new adaptive narrative centered around strengths. Family therapy approaches, based on experiential family therapy, the intersystem model, object relations family therapy, and the social ecology model, required a greater time commitment, but promoted disclosure of complex feelings and diffused tension. Family therapy genogram tools were feasible in practice, easy to implement, and effective at identifying communication barriers. Commentary articles highlighted the alignment of both approaches with genetic counseling goals and their potential value in practice. Utilization of psychotherapeutic approaches can improve counselors' ability to shape sessions, enhance insight and optimize efficacy, and flexibility in moving between models can maximize impact. This review highlights the paucity of studies investigating the efficacy of these psychotherapeutic approaches in the genetic counseling context and the need for more outcomes-based research on the utilization of narrative or family therapy in genetic counseling practice.

A new method to evaluate fluoroscopic system collimator performance.

INTRODUCTION: Fluoroscopy uses collimators to limit the radiation field size. Collimators are often evaluated annually during equipment performance evaluations to maintain compliance with regulatory and/or accreditation bodies. A method to evaluate and quantify fluoroscopy collimator performance was developed. METHODS: A radiation field and displayed image measurement device consisting of radiopaque rulers and radiochromic film strips was placed on the x-ray source assembly exit window to evaluate fluoroscopy collimator performance. This method was used to evaluate collimator performance on 79 fluoroscopic imaging systems including fixed C-arms, mobile C-arms, mini C-arms, and radiographic fluoroscopic systems. RESULTS: The excess length (EL), excess width (EW), and sum EL + EW of the radiation field relative to the displayed image were measured and compared to the limits specified in 21CFR1020.32. Four systems exceeded these limits. Placing the radiation measurement device at the x-ray source assembly exit window relative to the image receptor cover increased the film exposure rate by a factor up to 14.6. The time required to set up and complete the fluoroscopy collimator performance measurements using this method ranged from 5 to 10 min. CONCLUSIONS: This method provides an easily implemented quantitative measure of fluoroscopy system collimator performance that satisfies regulatory and accreditation body requirements.

The effect of obesity on adipose-derived stromal cells and adipose tissue and their impact on cancer.

The significant increase in the incidence of obesity represents the next global health crisis. As a result, scientific research has focused on gaining deeper insights into obesity and adipose tissue biology. As a result of the excessive accumulation of adipose tissue, obesity results from hyperplasia and hypertrophy within the adipose tissue. The functional alterations in the adipose tissue are a confounding contributing factor to many diseases, including cancer. The increased incidence and aggressiveness of several cancers, including colorectal, postmenopausal breast, endometrial, prostate, esophageal, hematological, malignant melanoma, and renal carcinomas, result from obesity as a contributing factor. The increased morbidity and mortality of obesity-associated cancers are attributable to increased hormones, adipokines, and cytokines produced by the adipose tissue. The increased adipose tissue levels observed in obese patients result in more adipose stromal/stem cells (ASCs) distributed throughout the body. ASCs have been shown to impact cancer progression in vitro and in preclinical animal models. ASCs influence tumor biology via multiple mechanisms, including the increased recruitment of ASCs to the tumor site and increased production of cytokines and growth factors by ASCs and other cells within the tumor stroma. Emerging evidence indicates that obesity induces alterations in the biological properties of ASCs, subsequently leading to enhanced tumorigenesis and metastasis of cancer cells. As the focus of this review is the interaction and impact of ASCs on cancer, the presentation is limited to preclinical data generated on cancers in which there is a demonstrated role for ASCs, such as postmenopausal breast, colorectal, prostate, ovarian, multiple myeloma, osteosarcoma, cervical, bladder, and gastrointestinal cancers. Our group has investigated the interactions between obesity and breast cancer and the mechanisms that regulate ASCs and adipocytes in these different contexts through interactions between cancer cells, immune cells, and other cell types present in the tumor microenvironment (TME) are discussed. The reciprocal and circular feedback loop between obesity and ASCs and the mechanisms by which ASCs from obese patients alter the biology of cancer cells and enhance tumorigenesis will be discussed. At present, the evidence for ASCs directly influencing human tumor growth is somewhat limited, though recent clinical studies suggest there may be some link.

Development and evaluation of a novel educational program for providers on the use of polygenic risk scores.

PURPOSE: This study aimed to develop an online educational program for using polygenic risk score (PRS) for breast and ovarian cancer risk assessments and to evaluate the impact on the attitudes, confidence, knowledge, and preparedness of genetic health care providers (GHPs). METHODS: The educational program comprises an online module that covers the theoretical aspects of PRS and a facilitated virtual workshop with prerecorded role-plays and case discussions. Data were collected in pre- and posteducation surveys. Eligible participants were GHPs working in Australian familial cancer clinics registered to recruit patients for a breast and ovarian cancer PRS clinical trial (n = 12). RESULTS: A total of 124 GHPs completed the PRS education, of whom 80 (64%) and 67 (41%) completed the pre- and posteducation surveys, respectively. Before education, GHPs reported limited experience, confidence, and preparedness using PRS, but they recognized its potential benefits. After education, GHPs indicated improved attitudes (P ≤ .001), confidence (P ≤ .001), knowledge (P ≤ .001), and preparedness (P ≤ .001) to use PRS. Most GHPs thought that the program entirely met their learning needs (73%) and was completely relevant to their clinical practice (88%). GHPs identified PRS implementation barriers, including limited funding models, diversity issues, and need for clinical guidelines. CONCLUSION: Our education program improved GHP attitudes, confidence, knowledge, and preparedness for using PRS/personalized risk and provides a framework for the development of future programs.

Models of communication for polygenic scores and associated psychosocial and behavioral effects on recipients: A systematic review.

PURPOSE: This study aimed to systematically review current models for communicating polygenic scores (PGS) and psycho-behavioral outcomes of receiving PGSs. METHODS: Original research on communicating PGSs and reporting on psycho-behavioral outcomes was included. Search terms were applied to 5 databases and were limited by date (2009-2021). RESULTS: In total, 28 articles, representing 17 studies in several disease settings were identified. There was limited consistency in PGS communication and evaluation/reporting of outcomes. Most studies (n = 14) presented risk in multiple ways (ie, numerically, verbally, and/or visually). Three studies provided personalized lifestyle advice and additional resources. Only 1 of 17 studies reported using behavior change theory to inform their PGS intervention. A total of 8 studies found no evidence of long-term negative psychosocial effects up to 12 months post result. Of 14 studies reporting on behavior, 9 found at least 1 favorable change after PGS receipt. When stratified by risk, 7 out of 9 studies found high PGS was associated with favorable changes including lifestyle, medication, and screening. Low-risk PGS was not associated with maladaptive behaviors (n = 4). CONCLUSION: PGS has the potential to benefit health behavior. High variability among studies emphasizes the need for developing standardized guidelines for communicating PGSs and evaluating psycho-behavioral outcomes. Our findings call for development of best communication practices and evidence-based interventions informed by behavior change theories.

[18F]FNDP PET neuroimaging test-retest repeatability and whole-body dosimetry in humans.

PURPOSE: Soluble epoxide hydrolase (sEH) is an enzyme that shapes immune signaling through its role in maintaining the homeostasis of polyunsaturated fatty acids and their related byproducts. [18F]FNDP is a radiotracer developed for use with positron emission tomography (PET) to image sEH, which has been applied to imaging sEH in the brains of healthy individuals. Here, we report the test-retest repeatability of [18F]FNDP brain PET binding and [18F]FNDP whole-body dosimetry in healthy individuals. METHODS: Seven healthy adults (4 men, 3 women, ages 40.1 ± 4.6 years) completed [18F]FNDP brain PET on two occasions within a period of 14 days in a test-retest study design. [18F]FNDP regional total distribution volume (VT) values were derived from modeling time-activity data with a metabolite-corrected arterial input function. Test-retest variability, mean absolute deviation, and intraclass correlation coefficient (ICC) were investigated. Six other healthy adults (3 men, 3 women, ages 46.0 ± 7.0 years) underwent [18F]FNDP PET/CT for whole-body dosimetry, which was acquired over 4.5 h, starting immediately after radiotracer administration. Organ-absorbed doses and the effective dose were then estimated. RESULTS: The mean test-retest difference in regional VT (ΔVT) was 0.82 ± 5.17%. The mean absolute difference in regional VT was 4.01 ± 3.33%. The ICC across different brain regions ranged from 0.92 to 0.99. The organs with the greatest radiation-absorbed doses included the gallbladder (0.081 ± 0.024 mSv/MBq), followed by liver (0.077 ± 0.018 mSv/MBq) and kidneys (0.063 ± 0.006 mSv/MBq). The effective dose was 0.020 ± 0.003 mSv/MBq. CONCLUSION: These data support a favorable test-retest repeatability of [18F]FNDP brain PET regional VT. The radiation dose to humans from each [18F]FNDP PET scan is similar to that of other 18F-based PET radiotracers.

Lineage tracing and analog recording in mammalian cells by single-site DNA writing.

Studying cellular and developmental processes in complex multicellular organisms can require the non-destructive observation of thousands to billions of cells deep within an animal. DNA recorders address the staggering difficulty of this task by converting transient cellular experiences into mutations at defined genomic sites that can be sequenced later in high throughput. However, existing recorders act primarily by erasing DNA. This is problematic because, in the limit of progressive erasure, no record remains. We present a DNA recorder called CHYRON (Cell History Recording by Ordered Insertion) that acts primarily by writing new DNA through the repeated insertion of random nucleotides at a single locus in temporal order. To achieve in vivo DNA writing, CHYRON combines Cas9, a homing guide RNA and the template-independent DNA polymerase terminal deoxynucleotidyl transferase. We successfully applied CHYRON as an evolving lineage tracer and as a recorder of user-selected cellular stimuli.

The MC1R r allele does not increase melanoma risk in MITF E318K carriers.

BACKGROUND: Population-wide screening for melanoma is not cost-effective, but genetic characterization could facilitate risk stratification and targeted screening. Common Melanocortin-1 receptor (MC1R) red hair colour (RHC) variants and Microphthalmia-associated transcription factor (MITF) E318K separately confer moderate melanoma susceptibility, but their interactive effects are relatively unexplored. OBJECTIVES: To evaluate whether MC1R genotypes differentially affect melanoma risk in MITF E318K+ vs. E318K- individuals. MATERIALS AND METHODS: Melanoma status (affected or unaffected) and genotype data (MC1R and MITF E318K) were collated from research cohorts (five Australian and two European). In addition, RHC genotypes from E318K+ individuals with and without melanoma were extracted from databases (The Cancer Genome Atlas and Medical Genome Research Bank, respectively). χ2 and logistic regression were used to evaluate RHC allele and genotype frequencies within E318K+/- cohorts depending on melanoma status. Replication analysis was conducted on 200 000 general-population exomes (UK Biobank). RESULTS: The cohort comprised 1165 MITF E318K- and 322 E318K+ individuals. In E318K- cases MC1R R and r alleles increased melanoma risk relative to wild type (wt), P < 0.001 for both. Similarly, each MC1R RHC genotype (R/R, R/r, R/wt, r/r and r/wt) increased melanoma risk relative to wt/wt (P < 0.001 for all). In E318K+ cases, R alleles increased melanoma risk relative to the wt allele [odds ratio (OR) 2.04 (95% confidence interval 1.67-2.49); P = 0.01], while the r allele risk was comparable with the wt allele [OR 0.78 (0.54-1.14) vs. 1.00, respectively]. E318K+ cases with the r/r genotype had a lower but not significant melanoma risk relative to wt/wt [OR 0.52 (0.20-1.38)]. Within the E318K+ cohort, R genotypes (R/R, R/r and R/wt) conferred a significantly higher risk compared with non-R genotypes (r/r, r/wt and wt/wt) (P < 0.001). UK Biobank data supported our findings that r did not increase melanoma risk in E318K+ individuals. CONCLUSIONS: RHC alleles/genotypes modify melanoma risk differently in MITF E318K- and E318K+ individuals. Specifically, although all RHC alleles increase risk relative to wt in E318K- individuals, only MC1R R increases melanoma risk in E318K+ individuals. Importantly, in the E318K+ cohort the MC1R r allele risk is comparable with wt. These findings could inform counselling and management for MITF E318K+ individuals.

Ensuring the quality and specificity of preregistrations.

Researchers face many, often seemingly arbitrary, choices in formulating hypotheses, designing protocols, collecting data, analyzing data, and reporting results. Opportunistic use of "researcher degrees of freedom" aimed at obtaining statistical significance increases the likelihood of obtaining and publishing false-positive results and overestimated effect sizes. Preregistration is a mechanism for reducing such degrees of freedom by specifying designs and analysis plans before observing the research outcomes. The effectiveness of preregistration may depend, in part, on whether the process facilitates sufficiently specific articulation of such plans. In this preregistered study, we compared 2 formats of preregistration available on the OSF: Standard Pre-Data Collection Registration and Prereg Challenge Registration (now called "OSF Preregistration," http://osf.io/prereg/). The Prereg Challenge format was a "structured" workflow with detailed instructions and an independent review to confirm completeness; the "Standard" format was "unstructured" with minimal direct guidance to give researchers flexibility for what to prespecify. Results of comparing random samples of 53 preregistrations from each format indicate that the "structured" format restricted the opportunistic use of researcher degrees of freedom better (Cliff's Delta = 0.49) than the "unstructured" format, but neither eliminated all researcher degrees of freedom. We also observed very low concordance among coders about the number of hypotheses (14%), indicating that they are often not clearly stated. We conclude that effective preregistration is challenging, and registration formats that provide effective guidance may improve the quality of research.

The Invariant NKT Cell Response Has Differential Signaling Requirements during Antigen-Dependent and Antigen-Independent Activation.

Invariant NKT (iNKT) cells are an innate-like population characterized by their recognition of glycolipid Ags and rapid cytokine production upon activation. Unlike conventional T cells, which require TCR ligation, iNKT cells can also be stimulated independently of their TCR. This feature allows iNKT cells to respond even in the absence of glycolipid Ags, for example, during viral infections. Although the TCR-dependent and -independent activation of iNKT cells have been relatively well established, the exact contributions of IL-12, IL-18, and TLRs remain unclear for these two activation pathways. To definitively investigate how these components affect the direct and indirect stimulation of iNKT cells, we used mice deficient for either MyD88 or the IL-12Rß2 in the T cell lineage. Using these tools, we demonstrate that IL-12, IL-18, and TLRs are completely dispensable for the TCR activation pathway when a strong agonist is used. In contrast, during murine CMV infection, when the TCR is not engaged, IL-12 signaling is essential, and TLR signaling is expendable. Importantly, to our knowledge, we discovered an intrinsic requirement for IL-18 signaling by splenic iNKT cells but not liver iNKT cells, suggesting that there might be diversity, even within the NKT1 population.

GM1 ganglioside modifies microglial and neuroinflammatory responses to α-synuclein in the rat AAV-A53T α-synuclein model of Parkinson's disease.

Among the pathological events associated with the dopaminergic neurodegeneration characteristic of Parkinson's disease (PD) are the accumulation of toxic forms of α-synuclein and microglial activation associated with neuroinflammation. Although numerous other processes may participate in the pathogenesis of PD, the two factors mentioned above may play critical roles in the initiation and progression of dopamine neuron degeneration in PD. In this study, we employed a slowly progressing model of PD using adeno-associated virus-mediated expression of human A53T α-synuclein into the substantia nigra on one side of the brain and examined the microglial response in the striatum on the injected side compared to the non-injected (control) side. We further examined the extent to which administration of the neuroprotective ganglioside GM1 influenced α-synuclein-induced glial responses. Changes in a number of microglial morphological measures (i.e., process length, number of endpoints, fractal dimension, lacunarity, density, and cell perimeter) were indicative of the presence of activated microglial and an inflammatory response on the injected side of the brain, compared to the control side. In GM1-treated animals, no significant differences in microglial morphology were observed between the injected and control striata. Follow-up studies showed that mRNA expression for several inflammation-related genes was increased on the A53T α-synuclein injected side vs. the non-injected side in saline-treated animals and that such changes were not observed in GM1-treated animals. These data show that inhibition of microglial activation and potentially damaging neuroinflammation by GM1 ganglioside administration may be among the many factors that contribute to the neuroprotective effects of GM1 in this model and possibly in human PD.