Molecular mechanism of BMP signal control by Twisted gastrulation

Twisted gastrulation (TWSG1) is an evolutionarily conserved secreted glycoprotein which controls signaling by Bone Morphogenetic Proteins (BMPs). TWSG1 binds BMPs and their antagonist Chordin to control BMP signaling during embryonic development, kidney regeneration and cancer. We report crystal structures of TWSG1 alone and in complex with a BMP ligand, Growth Differentiation Factor 5. TWSG1 is composed of two distinct, disulfide-rich domains. The TWSG1 N-terminal domain occupies the BMP type 1 receptor binding site on BMPs, whereas the C-terminal domain binds to a Chordin family member. We show that TWSG1 inhibits BMP function in cellular signaling assays and mouse colon organoids. This inhibitory function is abolished in a TWSG1 mutant that cannot bind BMPs. The same mutation in the Drosophila TWSG1 ortholog Tsg fails to mediate BMP gradient formation required for dorsal-ventral axis patterning of the early embryo. Our studies reveal the evolutionarily conserved mechanism of BMP signaling inhibition by TWSG1

Antidepressants for the prevention of depression following first-episode psychosis (ADEPP): study protocol for a multi-centre, double-blind, randomised controlled trial

Background: Depressive episodes are common after first-episode psychosis (FEP), affecting more than 40% of people, adding to individual burden, poor outcomes, and healthcare costs. If the risks of developing depression were lower, this could have a beneficial effect on morbidity and mortality, as well as improving outcomes. Sertraline is a selective serotonin reuptake inhibitor and a common first-line medication for the treatment of depression in adults. It has been shown to be safe when co-prescribed with antipsychotic medication, and there is evidence that it is an effective treatment for depression in established schizophrenia. We present a protocol for a multi-centre, double-blind, randomised, placebo-controlled clinical trial called ADEPP that aims to investigate the efficacy and cost-effectiveness of sertraline in preventing depression after FEP. Methods: The recruitment target is 452 participants between the ages of 18 and 65 years who are within 12 months of treatment initiation for FEP. Having provided informed consent, participants will be randomised to receive either 50 mg of sertraline daily or matched placebo for 6 months, in addition to treatment as usual. The primary outcome measure will be a comparison of the number of new cases of depression between the treatment and placebo arms over the 6-month intervention phase. Secondary outcomes include suicidal behaviour, anxiety, rates of relapse, functional outcome, quality of life, and resource use. Discussion: The ADEPP trial will test whether the addition of sertraline following FEP is a clinically useful, acceptable, and cost-effective way of improving outcomes following FEP. Trial registration: ISRCTN12682719 registration date 24/11/2020

SARS-CoV-2 susceptibility and COVID-19 disease severity are associated with genetic variants affecting gene expression in a variety of tissues

Variability in SARS-CoV-2 susceptibility and COVID-19 disease severity between individuals is partly due to genetic factors. Here, we identify 4 genomic loci with suggestive associations for SARS-CoV-2 susceptibility and 19 for COVID-19 disease severity. Four of these 23 loci likely have an ethnicity-specific component. Genome-wide association study (GWAS) signals in 11 loci colocalize with expression quantitative trait loci (eQTLs) associated with the expression of 20 genes in 62 tissues/cell types (range: 1:43 tissues/gene), including lung, brain, heart, muscle, and skin as well as the digestive system and immune system. We perform genetic fine mapping to compute 99% credible SNP sets, which identify 10 GWAS loci that have eight or fewer SNPs in the credible set, including three loci with one single likely causal SNP. Our study suggests that the diverse symptoms and disease severity of COVID-19 observed between individuals is associated with variants across the genome, affecting gene expression levels in a wide variety of tissue types

A first update on mapping the human genetic architecture of COVID-19

peer reviewe

Light painting photography makes particulate matter air pollution visible

The World Health Organization estimates that air pollution causes approximately seven million premature deaths worldwide each year. Solutions to air pollution are well known, yet this rarely equates to easily actionable. Here we demonstrate how art science collaboration can successfully highlight the issue of air pollution and create wider civic discourse around its amelioration. We document a light painting photographic technique that uses data from calibrated low-cost particulate matter sensors to measure and depict air pollution. We also use a postcard technique to grasp individuals’ sentiments regarding air pollution. The photographs from three countries, Ethiopia, India and United Kingdom, visually highlight the importance of location and occupation upon human exposure. The photographs are used as a proxy to communicate and create dialogues, spaces and places about air pollution. The sentiment analysis show how this approach can foster awareness and create agency for stakeholders to take actions to tackle air pollution

Diversity of T cells restricted by the MHC class I-related molecule MR1 facilitates differential antigen recognition

A characteristic of mucosal-associated invariant T (MAIT) cells is the expression of TRAV1-2(+) T cell receptors (TCRs) that are activated by riboflavin metabolite- based antigens (Ag) presented by the MHC-I related molecule, MR1. Whether the MR1-restricted T cell repertoire and associated Ag responsiveness extends beyond these cells remains unclear. Here, we describe MR1 autoreactivity and folate-derivative reactivity in a discrete subset of TRAV1-2(+) MAIT cells. This recognition was attributable to CDR3 beta loop-mediated effects within a consensus TRAV1-2(+) TCR-MR1-Ag footprint. Furthermore, we have demonstrated differential folate-and riboflavin-derivative reactivity by a diverse population of "atypical'' TRAV1-2(-) MR1-restricted T cells. We have shown that TRAV1-2(-) T cells are phenotypically heterogeneous and largely distinct from TRAV1-2(+) MAIT cells. A TRAV1-2(-) TCR docks more centrally on MR1, thereby adopting a markedly different molecular footprint to the TRAV1-2(+) TCR. Accordingly, diversity within the MR1-restricted T cell repertoire leads to differing MR1-restricted Ag specificity

Modeling the role of negative symptoms in determining social functioning in individuals at clinical high risk of psychosis

A priority for improving outcome in individuals at clinical high risk (CHR) is enhancing our understanding of predictors of psychosis as well as psychosocial functioning. Social functioning, in particular, is a unique indicator of risk as well as an important outcome in itself. Negative symptoms are a significant determinant of social functioning in CHR individuals; yet, it is unclear which specific negative symptoms drive functional outcome and how these symptoms function relative to other predictors, such as neurocognition and mood/anxiety symptoms. In a sample of 85 CHR individuals, we examined whether a two-factor negative symptom structure that is found in schizophrenia (experiential vs expressive symptoms) would be replicated in a CHR sample; and tested the degree to which specific negative symptoms predict social functioning, relative to neurocognition and mood/anxiety symptoms, which are known to predict functioning. The two-factor negative symptom solution was replicated in this CHR sample. Negative symptom severity was found to be uniquely predictive of social functioning, above and beyond depression/anxiety and neurocognition. Experiential symptoms were more strongly associated with social functioning, relative to expression symptoms. In addition, experiential symptoms mediated the relationship between expressive negative symptoms and social functioning. These results suggest that experiences of motivational impairment are more important in determining social functioning, relative to affective flattening and alogia, in CHR individuals, thereby informing the development of more precise therapeutic targets. Developing novel interventions that stimulate goal-directed behavior and reinforce rewarding experiences in social contexts are recommended

Hepatitis B transmission/reactivation associated with Hepatitis B core antibody and Hepatitis C nucleic acid testing positive organs: A report from the Organ Procurement and Transplantation Network Disease Transmission Advisory Committee

Background: Better access to direct-acting antiviral (DAA) therapy has broadened the utilization of hepatitis C virus (HCV) nucleic acid testing (NAT) positive organs with excellent outcomes. However, DAA therapy has been associated with hepatitis B virus (HBV) reactivation. Aim: To determine the risk of HBV transmission or reactivation with utilization of HBV core antibody positive (HBcAb+) and HCV NAT positive (HCV+) organs, which presumably required DAA therapy. Methods: The number of HBcAb+ donors with delineated HCV NAT status was obtained from the Organ Procurement and Transplantation Network (OPTN) database. The number of unexpected HBV infections from transplanted organs adjudicated as "proven" or "probable" transmission was obtained from the OPTN Ad Hoc Disease Transmission Advisory Committee database. A chart review of the donors of "proven" or "probable" cases was conducted. Results: From January 1, 2016, to December 31, 2021, 7735 organs were procured from 3767 HBcAb+ donors and transplanted into 7469 recipients; 545 (14.5%) donors were also HCV+. HBV transmission or reactivation occurred in seven recipients. The rate is not significantly different between recipients of HCV+ (0.18%, 2/1115) and the HCV NAT negative (HCV-) organs (0.08%, 5/6354) (p = 0.28) or between recipients of HCV+ and HCV- livers as well as non-liver organs. HBV transmission or reactivation occurred within a median of 319 (range, 41-1117) days post-transplant in the setting of missing, inadequate, or truncated prophylaxis. Conclusion: HBV reactivation associated with DAA therapy for HBcAb+ HCV+ organs is less frequent than reported in the non-transplant population, possibly due to the common use of HBV prophylaxis in the at-risk transplant population.</p