Abnormal DUX4 expression in skeletal muscles plays a key role in facioscapulohumeral muscular dystrophy (FSHD) pathogenesis, although the molecular mechanisms regulating DUX4 expression are not fully ...defined. Using bioinformatic analysis of the genomic DUX4 locus, we have identified a number of putative G-quadruplexes (GQs) forming sequences. Their presence was confirmed in synthetic oligonucleotiode sequences derived from the enhancer, promoter and transcript of DUX4 through circular dichroism and nuclear magnetic resonance analysis. We further examined the binding affinity of a naturally occurring GQ stabilizing compound, berberine, to these non-canonical genetic structures using UV-Vis and fluorescence spectroscopy. Subsequent in vitro study in FSHD patient myoblasts indicated that berberine treatment reduced DUX4 expression and also expression of genes normally switched on by DUX4. Further investigation in a mouse model overexpressing exogenous DUX4 confirmed the therapeutic effects of berberine in downregulating DUX4 protein expression, inhibiting muscle fibrosis, and consequently rescuing muscle function. Our data demonstrate for the first time that GQs are present in the DUX4 locus and that the GQ interactive ligand reduces DUX4 expression suggesting potential role of GQs in FSHD pathogenesis. Our work provides the basis of a novel therapeutic strategy for the treatment of FSHD.
BLM (Bloom syndrome protein) is a RECQ-family helicase involved in the dissolution of complex DNA structures and repair intermediates. Synthetic lethality analysis implicates BLM as a promising ...target in a range of cancers with defects in the DNA damage response; however, selective small molecule inhibitors of defined mechanism are currently lacking. Here, we identify and characterise a specific inhibitor of BLM's ATPase-coupled DNA helicase activity, by allosteric trapping of a DNA-bound translocation intermediate. Crystallographic structures of BLM-DNA-ADP-inhibitor complexes identify a hitherto unknown interdomain interface, whose opening and closing are integral to translocation of ssDNA, and which provides a highly selective pocket for drug discovery. Comparison with structures of other RECQ helicases provides a model for branch migration of Holliday junctions by BLM.
The costimulatory receptor 4-1BB is expressed on activated immune cells, including activated T cells. Antibodies targeting 4-1BB enhance the proliferation and survival of antigen-stimulated T cells ...in vitro and promote CD8 T cell-dependent anti-tumor immunity in pre-clinical cancer models. We found that T regulatory (Treg) cells infiltrating human or murine tumors expressed high amounts of 4-1BB. Intra-tumoral Treg cells were preferentially depleted by anti-4-1BB mAbs in vivo. Anti-4-1BB mAbs also promoted effector T cell agonism to promote tumor rejection. These distinct mechanisms were competitive and dependent on antibody isotype and FcγR availability. Administration of anti-4-1BB IgG2a, which preferentially depletes Treg cells, followed by either agonistic anti-4-1BB IgG1 or anti-PD-1 mAb augmented anti-tumor responses in multiple solid tumor models. An antibody engineered to optimize both FcγR-dependent Treg cell depleting capacity and FcγR-independent agonism delivered enhanced anti-tumor therapy. These insights into the effector mechanisms of anti-4-1BB mAbs lay the groundwork for translation into the clinic.
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•Anti-4-1BB IgG2a depletes intratumoral Treg cells; IgG1 promotes CD8 T cell function•The efficacy of anti-4-1BB mIgG1 and anti-4-1BB mIgG2a depends on different FcγRs•Optimal tumor therapy requires sequential anti-4-1BB IgG2a and IgG1 or PD-1 blockade•Hinge-engineered anti-4-1BB mIgG2a/h2B mAb harnesses both mechanisms of action
Buchan et al. reveal dual anti-tumor activities for antibodies to the co-stimulatory receptor 4-1BB, which depend on antibody isotype and FcγR availability. Sequential scheduling of anti-4-1BB and checkpoint blockade mAbs, and antibodies engineered to harness both Treg cell depleting and effector cell agonism properties show potent anti-tumor activity in preclinical models, laying the groundwork for translation into the clinic.
In the RV144 trial, the estimated efficacy of a vaccine regimen against human immunodeficiency virus type 1 (HIV-1) was 31.2%. We performed a case-control analysis to identify antibody and cellular ...immune correlates of infection risk.
In pilot studies conducted with RV144 blood samples, 17 antibody or cellular assays met prespecified criteria, of which 6 were chosen for primary analysis to determine the roles of T-cell, IgG antibody, and IgA antibody responses in the modulation of infection risk. Assays were performed on samples from 41 vaccinees who became infected and 205 uninfected vaccinees, obtained 2 weeks after final immunization, to evaluate whether immune-response variables predicted HIV-1 infection through 42 months of follow-up.
Of six primary variables, two correlated significantly with infection risk: the binding of IgG antibodies to variable regions 1 and 2 (V1V2) of HIV-1 envelope proteins (Env) correlated inversely with the rate of HIV-1 infection (estimated odds ratio, 0.57 per 1-SD increase; P=0.02; q=0.08), and the binding of plasma IgA antibodies to Env correlated directly with the rate of infection (estimated odds ratio, 1.54 per 1-SD increase; P=0.03; q=0.08). Neither low levels of V1V2 antibodies nor high levels of Env-specific IgA antibodies were associated with higher rates of infection than were found in the placebo group. Secondary analyses suggested that Env-specific IgA antibodies may mitigate the effects of potentially protective antibodies.
This immune-correlates study generated the hypotheses that V1V2 antibodies may have contributed to protection against HIV-1 infection, whereas high levels of Env-specific IgA antibodies may have mitigated the effects of protective antibodies. Vaccines that are designed to induce higher levels of V1V2 antibodies and lower levels of Env-specific IgA antibodies than are induced by the RV144 vaccine may have improved efficacy against HIV-1 infection.
Background:
The incidence and effect of sports-related concussions (SRCs) within the global sport of professional soccer is poorly described.
Purpose:
To comparatively examine the effects of SRC on ...athletes in Major League Soccer (MLS) and the English Premier League (EPL) in terms of incidence, return to play (RTP), performance, and career longevity.
Study Design:
Cohort study; Level of evidence, 3.
Methods:
Contracts, transactions, injury reports, and performance statistics from 2008 to 2017 were obtained and cross-referenced across 6 publicly available websites detailing MLS and EPL data, including official league publications. For each league, players who sustained a concussion were compared with the 2008-2017 uninjured player pool. RTP and games missed were analyzed and compared. Career length was analyzed with Kaplan-Meier survival curves. Player performance changes were evaluated before and after concussion.
Results:
Of the 1784 eligible MLS and 2001 eligible EPL players evaluated over the 10-year period, the incidence of publicly reported concussions per 1000 athlete-exposures was 20.22 and 18.68, respectively (P = .53). The incidence of reported concussions steadily increased in both leagues. MLS players missed a mean 7.3 games after concussion (37.0 days missed); EPL players missed a mean 0.6 games after concussion (10.9 days missed) (P < .0001, P < .0001). Statistical performance in terms of games started, assists, shots on goal, and total shots after concussion was significantly reduced at all nongoalie positions for players in the EPL; however, MLS nongoalie positions with concussion had no significant decreases in these categories. Goalies in both leagues had no significant change in performance or games started. The probability of playing a full season after concussion was not significantly decreased when compared with the uninjured pool in both leagues.
Conclusion:
This study established the SRC incidence among elite soccer players in 2 international professional leagues and identified major RTP and performance differences between EPL and MLS players. While career longevity was unaffected, the approach to managing concussion as in MLS may better promote player safety and preserve on-field performance.
Although repetitive transcranial magnetic stimulation ('TMS') is becoming a gold standard treatment for pharmacoresistant depression, we lack neural target biomarkers for identifying who is most ...likely to respond to TMS and why. To address this gap in knowledge we evaluate neural targets defined by activation and functional connectivity of the dorsolateral prefrontal cortex-anchored cognitive control circuit, regions of the default mode network and attention circuit, and interactions with the subgenual anterior cingulate. We evaluate whether these targets and interactions between them change in a dose-dependent manner, whether changes in these neural targets correspond to changes in cognitive behavioral performance, and whether baseline and early change in neural target and cognitive behavioral performance predict subsequent symptom severity, suicidality, and quality of life outcomes. This study is designed as a pragmatic, mechanistic trial partnering with the National Clinical TMS Program of the Veteran's Health Administration.
Target enrollment consists of 100 veterans with pharmacoresistant Major Depressive Disorder (MDD). All veterans will receive a clinical course of TMS and will be assessed at 'baseline' pre-TMS commencement, 'first week' after initiation of TMS (targeting five sessions) and 'post-treatment' at the completion of TMS (targeting 30 sessions). Veterans will be assessed using functional magnetic resonance imaging (fMRI), a cognitive behavioral performance battery, and established questionnaires. Multivariate linear mixed models will be used to assess whether neural targets change with TMS as a function of dose (Aim 1), whether extent and change of neural target relates to and predicts extent of behavioral performance (Aim 3), and whether extent of neural target change predicts improvement in symptom severity, suicidality, and quality of life (Aim 3). For all three aims, we will also assess the contribution of baseline moderators such as biological sex and age.
To our knowledge, our study will be the first pragmatic, mechanistic observational trial to use fMRI imaging and cognitive-behavioral performance as biomarkers of TMS treatment response in pharmacoresistant MDD. The results of this trial will allow providers to select suitable candidates for TMS treatment and better predict treatment response by assessing circuit connectivity and cognitive-behavioral performance at baseline and during early treatment.
ClinicalTrials.gov NCT04663481 , December 5th, 2020, retrospectively registered. The first veteran was enrolled October 30th, 2020.
Measurements of the isotopic composition of separate and
potentially interacting pools of soil water provide a powerful means to
precisely resolve plant water sources and quantify water residence ...time and
connectivity among soil water regions during recharge events. Here we
present an approach for quantifying the time-dependent isotopic mixing of
water recovered at separate suction pressures or tensions in soil over an
entire moisture release curve. We wetted oven-dried, homogenized sandy loam
soil first with isotopically “light” water (δ2H =-130 ‰; δ18O =-17.6 ‰) to represent antecedent moisture held at high matric tension. We then
brought the soil to near saturation with “heavy” water (δ2H =-44 ‰; δ18O =-7.8 ‰) that represented new input water. Soil water samples
were subsequently sequentially extracted at three tensions (“low-tension”
centrifugation ≈0.016 MPa; “mid-tension” centrifugation ≈1.14 MPa; and “high-tension” cryogenic vacuum distillation at an
estimated tension greater than 100 MPa) after variable
equilibration periods of 0 h, 8 h, 1 d, 3 d, and 7 d. We assessed the differences
in the isotopic composition of extracted water over the 7 d equilibration
period with a MANOVA and a model quantifying the time-dependent isotopic mixing
of water towards equilibrium via self-diffusion. The simplified and
homogenous soil structure and nearly saturated moisture conditions used in
our experiment likely facilitated rapid isotope mixing and equilibration
among antecedent and new input water. Despite this, the isotope composition
of waters extracted at mid compared with high tension remained significantly
different for up to 1 d, and waters extracted at low compared with
high tension remained significantly different for longer than 3 d.
Complete mixing (assuming no fractionation) for the pool of water extracted
at high tension occurred after approximately 4.33 d. Our combination
approach involving the extraction of water over different domains of the
moisture release curve will be useful for assessing how soil texture and
other physical and chemical properties influence isotope exchange and mixing
times for studies aiming to properly characterize and interpret the isotopic
composition of extracted soil and plant waters, especially under variably
unsaturated conditions.
Summer streamflow predictions are critical for managing water resources; however, warming‐induced shifts from snow to rain regimes impact low‐flow predictive models. Additionally, reductions in ...snowpack drive earlier peak flows and lower summer flows across the western United States increasing reliance on groundwater for maintaining summer streamflow. However, it remains poorly understood how groundwater contributions vary interannually. We quantify recession limb groundwater (RLGW), defined as the proportional groundwater contribution to the stream during the period between peak stream flow and low flow, to predict summer low flows across three diverse western US watersheds. We ask (a) how do snow and rain dynamics influence interannual variations of RLGW contributions and summer low flows?; (b) which watershed attributes impact the effectiveness of RLGW as a predictor of summer low flows? Linear models reveal that RLGW is a strong predictor of low flows across all sites and drastically improves low‐flow prediction compared to snow metrics at a rain‐dominated site. Results suggest that strength of RLGW control on summer low flows may be mediated by subsurface storage. Subsurface storage can be divided into dynamic (i.e., variability saturated) and deep (i.e., permanently saturated) components, and we hypothesize that interannual variability in dynamic storage contribution to streamflow drives RLGW variability. In systems with a higher proportion of dynamic storage, RLGW is a better predictor of summer low flow because the stream is more responsive to dynamic storage contributions compared to deep‐storage‐dominated systems. Overall, including RLGW improved low‐flow prediction across diverse watersheds.
Plain Language Summary
Water managers across the western United States depend on accurate streamflow prediction models for water planning and allocation during summer months. Historically, these models use snow metrics to predict summer flows, but increasing temperatures across the western US are decreasing snow input and accumulation and increasing early snow melt rates leading to changes in streamflow generation mechanisms. Here, we seek to understand how stream flows will respond under warmer climates in three watersheds with distinct climate and underlying bedrock in the western US. We expanded upon commonly used low‐flow model snow metrics to include snow and streamflow metrics from the previous year as well as groundwater dynamics during the annual recession curve. We found that including variables outside of commonly used snow parameters in the models produced more accurate predictions of summer low flows. We provide a framework for future analysis of streamflow response to warming across the western US.
Key Points
Recession limb groundwater proportion is a strong predictor of summer low flows
Recession limb dynamics are especially important for improving low‐flow prediction at rain‐dominated sites
Recession limb groundwater may be a better predictor of low flow at sites where dynamic storage exceeds deep storage
Small series have identified a relationship between preoperative hematocrit (HCT) and outcomes in coronary artery bypass graft (CABG) surgery. The Society of Thoracic Surgeons (STS) Adult Cardiac ...Surgery Database (ACSD) began collecting preoperative HCT data in 2008. In this study, analyses were performed to determine the impact of preoperative HCT on perioperative morbidity and mortality among patients undergoing isolated CABG.
Data were collected on 182,599 patients who underwent primary isolated on-pump CABG between 2008 and 2009 and were included in the STS ACSD. Data were included only from centers that performed more than 100 on-pump cases per year during the period of study. Dialysis patients as well as those with previous cardiovascular operations or missing data for HCT were excluded. We then performed multivariable analysis using the 2008 STS CABG risk model as a guide, including HCT as a predictor. Logistic regression was performed for operative mortality and other adverse outcomes.
Overall operative mortality was 1.6% (3,005 of 182,599). Compared with patients with anemia (HCT <33%), patients with HCT of at least 42% had lower mortality (1.1% versus 3.4%; p < 0.0001) and lower rates of renal failure (2.0% versus 7.8%; p < 0.0001), stroke (0.9% versus 1.8%; p < 0.0001), prolonged ventilation (8.4% versus 17.5%; p < 0.0001), and deep sternal wound infection (0.3% versus 0.6%; p < 0.0001). In adjusted analyses, each 5-point decrease in preoperative HCT was associated with an 8% higher odds of death (odds ratio, 1.08; p = 0.0003), a 22% increase in the odds of postoperative renal failure (odds ratio, 1.22; p < 0.0001), and a 10% increase in the risk of deep sternal wound infection (odds ratio, 1.10; p < 0.01). Similar results were observed among patients (n = 74,292) undergoing elective CABG. The percentage of patients receiving perioperative blood transfusion decreased from 88.5% in the anemic group (HCT <33%) to 32.5% in patients with HCT of at least 42% (p < 0.0001).
Preoperative HCT is a powerful independent predictor of perioperative mortality as well as renal failure and deep sternal wound infection in patients undergoing isolated primary CABG operations. These findings should prompt investigation of strategies to increase preoperative HCT.
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