385 research outputs found
Industrial Melanism in the Peppered Moth Is Not Associated with Genetic Variation in Canonical Melanisation Gene Candidates
Industrial melanism in the peppered moth (Biston betularia) is an iconic case study of ecological genetics but the molecular identity of the gene determining the difference between the typical and melanic (carbonaria) morphs is entirely unknown. We applied the candidate gene approach to look for associations between genetic polymorphisms within sixteen a priori melanisation gene candidates and the carbonaria morph. The genes were isolated and sequence characterised in B. betularia using degenerate PCR and from whole-transcriptome sequence. The list of candidates contains all the genes previously implicated in melanisation pattern differences in other insects, including aaNAT, DOPA-decarboxylase, ebony, tan, tyrosine hydroxylase, yellow and yellow2 (yellow-fa). Co-segregation of candidate gene alleles and carbonaria morph was tested in 73 offspring of a carbonaria male-typical female backcross. Surprisingly, none of the sixteen candidate genes was in close linkage with the locus controlling the carbonaria-typical polymorphism. Our study demonstrates that the ‘carbonaria gene’ is not a structural variant of a canonical melanisation pathway gene, neither is it a cis-regulatory element of these enzyme-coding genes. The implication is either that we have failed to characterize an unknown enzyme-coding gene in the melanisation pathway, or more likely, that the ‘carbonaria gene’ is a higher level trans-acting factor which regulates the spatial expression of one or more of the melanisation candidates in this study to alter the pattern of melanin production
Insertion mutation in Tnfrsf11a causes a Paget's disease-like phenotype in heterozygous mice and osteopetrosis in homozygous mice
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Adaptive colour change and background choice behaviour in peppered moth caterpillars is mediated by extraocular photoreception.
Light sensing by tissues distinct from the eye occurs in diverse animal groups, enabling circadian control and phototactic behaviour. Extraocular photoreceptors may also facilitate rapid colour change in cephalopods and lizards, but little is known about the sensory system that mediates slow colour change in arthropods. We previously reported that slow colour change in twig-mimicking caterpillars of the peppered moth (Biston betularia) is a response to achromatic and chromatic visual cues. Here we show that the perception of these cues, and the resulting phenotypic responses, does not require ocular vision. Caterpillars with completely obscured ocelli remained capable of enhancing their crypsis by changing colour and choosing to rest on colour-matching twigs. A suite of visual genes, expressed across the larval integument, likely plays a key role in the mechanism. To our knowledge, this is the first evidence that extraocular colour sensing can mediate pigment-based colour change and behaviour in an arthropod
Recessive Z-linked lethals and the retention of haplotype diversity in a captive butterfly population
Sex chromosomes are predicted to harbour elevated levels of sexually antagonistic variation due to asymmetries in the heritability of recessive traits in the homogametic versus heterogametic sex. This evolutionary dynamic may manifest as high recessive load specifically affecting the homogametic sex, and the retention of haplotype diversity in small populations. We tested the hypothesis that the Z chromosome in the butterfly Bicyclus anynana carries a high inbred load for male fertility and viability. Homozygosity of Z chromosome blocks was produced by daughter–father backcrosses, and inferred from marker loci positioned via a linkage map. Male sterility was, in general, unrelated to homozygosity in any region of the Z, but there was an extreme deficit of homozygous males within a 2 cM interval in all families. In contrast, no corresponding skew in Z genotype was detected in their (hemizygous) sisters. The same pattern was observed in historically inbred lines, indicating a high frequency of recessive lethals in the ancestral population. Allele-frequency changes between 1993 and 2006 (70 generations at Ne ~ 160) show that, despite the loss of many haplotypes, diversity was retained significantly above the neutral expectation. Effective overdominance in the lethal region can account for this effect locally but not in other parts of the chromosome, that are also associated with persistent linkage disequilibrium. These unexpected patterns suggest the operation of other factors, such as epistatic selection, recombination suppression, assortative mating and meiotic drive. Our results highlight the role of balancing selection in maintaining the inbred load and linked genetic diversity
Human Hematopoietic Stem, Progenitor, and Immune Cells Respond Ex Vivo to SARS-CoV-2 Spike Protein
This article is made available for unrestricted research re-use and secondary analysis in any form or by any means with acknowledgement of the original source. These permissions are granted for the duration of the World Health Organization (WHO) declaration of COVID-19 as a global pandemic.Despite evidence that SARS-CoV-2 infection is systemic in nature, there is little known about the effects that SARS-CoV-2 infection or exposure has on many host cell types, including primitive and mature hematopoietic cells. The hematopoietic system is responsible for giving rise to the very immune cells that defend against viral infection and is a source of hematopoietic stem cells (HSCs) and progenitor cells (HPCs) which are used for hematopoietic cell transplantation (HCT) to treat hematologic disorders, thus there is a strong need to understand how exposure to the virus may affect hematopoietic cell functions. We examined the expression of ACE2, to which SARS-CoV-2 Spike (S) protein binds to facilitate viral entry, in cord blood derived HSCs/HPCs and in peripheral blood derived immune cell subtypes. ACE2 is expressed in low numbers of immune cells, higher numbers of HPCs, and up to 65% of rigorously defined HSCs. We also examined effects of exposing HSCs/HPCs and immune cells to SARS-CoV-2 S protein ex vivo. HSCs and HPCs expand less effectively and have less functional colony forming capacity when grown with S protein, while peripheral blood monocytes upregulate CD14 expression and show distinct changes in size and granularity. That these effects are induced by recombinant S protein alone and not the infectious viral particle suggests that simple exposure to SARS-CoV-2 may impact HSCs/HPCs and immune cells via S protein interactions with the cells, regardless of whether they can be infected. These data have implications for immune response to SARS-CoV-2 and for HCT
TSG-6 protects cartilage and bone by modulating the activities of chondrocytes and osteoclasts: a potential therapeutic for musculoskeletal disorders
Guided digital health intervention for depression in Lebanon: randomised trial
<jats:sec><jats:title>Background</jats:title><jats:p>Most people with mental disorders in communities exposed to adversity in low-income and middle-income countries (LMICs) do not receive effective care. Digital mental health interventions are scalable when digital access is adequate, and can be safely delivered during the COVID-19 pandemic.</jats:p></jats:sec><jats:sec><jats:title>Objective</jats:title><jats:p>To examine the effects of a new WHO-guided digital mental health intervention, Step-by-Step, supported by a non-specialist helper in Lebanon, in the context of concurring economic, humanitarian and political crises, a large industrial disaster and the COVID-19 pandemic.</jats:p></jats:sec><jats:sec><jats:title>Methods</jats:title><jats:p>We conducted a single-blind, two-arm pragmatic randomised trial, comparing guided Step-by-Step with enhanced care as usual (ECAU) among people suffering from depression and impaired functioning. Primary outcomes were depression (Patient Health Questionnaire 9 (PHQ-9)) and impaired functioning (WHO Disability Assessment Schedule-12 (WHODAS)) at post-treatment.</jats:p></jats:sec><jats:sec><jats:title>Findings</jats:title><jats:p>680 people with depression (PHQ-9&gt;10) and impaired functioning (WHODAS&gt;16) were randomised to Step-by-Step or ECAU. Intention-to-treat analyses showed effects on depression (standardised mean differences, SMD: 0.71; 95% CI: 0.45 to 0.97), impaired functioning (SMD: 0.43; 95% CI: 0.21 to 0.65), post-traumatic stress (SMD: 0.53; 95% CI: 0.27 to 0.79), anxiety (SMD: 0.74; 95% CI: 0.49 to 0.99), subjective well-being (SMD: 0.37; 95% CI: 0.12 to 0.62) and self-identified personal problems (SMD: 0.56; 95% CI 0.29 to 0.83). Significant effects on all outcomes were retained at 3-month follow-up.</jats:p></jats:sec><jats:sec><jats:title>Conclusions</jats:title><jats:p>Guided digital mental health interventions can be effective in the treatment of depression in communities exposed to adversities in LMICs, although some uncertainty remains because of high attrition.</jats:p></jats:sec><jats:sec><jats:title>Clinical implications</jats:title><jats:p>Guided digital mental health interventions should be considered for implementation in LMICs.</jats:p></jats:sec><jats:sec><jats:title>Trial registration number</jats:title><jats:p>ClinicalTrials.gov <jats:ext-link xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="clintrialgov" xlink:href="NCT03720769">NCT03720769</jats:ext-link>.</jats:p></jats:sec>
IFN-γ and PPARδ Influence the Efficacy and Retention of Multipotent Adult Progenitor Cells in Graft vs Host Disease
Cell-based therapy for the treatment of inflammatory disorders has focused on the
application of mesenchymal stromal cells (MSCs) and multipotent adult progenitor
cells (MAPCs). Despite the recent positive findings in industry-sponsored clinical trials of MSCs and MAPCs for graft vs host disease (GvHD), cell therapy is efficacious
in some but not all patients, highlighting the need to identify strategies to enhance
cell-based therapeutic efficacy. Here, we demonstrate the capacity for interferon
(IFN)-γ licensing to enhance human MAPC efficacy and retention following early
administration in a humanized mouse model of acute GvHD (aGvHD). Activation of
the nuclear receptor peroxisome proliferator-activated receptor delta (PPARδ) negatively influenced the retention and efficacy of human MAPCs as well as IFNγ-licensed MAPCs in the aGvHD model. PPARδ antagonism significantly enhanced
the efficacy of human MAPCs when administered early in the humanized aGvHD
model. COX-2 expression in human MAPC was significantly decreased in IFN-γ
licensed MAPCs exposed to a PPARδ agonist. Importantly, MAPC exposure to the
PPARδ antagonist in the presence of a COX-2 inhibitor indomethacin before administration significantly reduced the efficacy of PPARδ antagonized MAPCs in the
aGvHD humanized mouse model. This is the first study to demonstrate the importance of PPARδ in human MAPC efficacy in vivo and highlights the importance of
understanding the disease microenvironment in which cell-based therapies are to be
administered. In particular, the presence of PPARδ ligands may negatively influence
MAPC or MSC therapeutic efficacy
Changes and prognostic value of cardiopulmonary exercise testing parameters in elderly patients undergoing cardiac rehabilitation: The EU-CaRE observational study
Objective We aimed 1) to test the applicability of the previously suggested prognostic value of CPET to elderly cardiac rehabilitation patients and 2) to explore the underlying mechanism of the greater improvement in exercise capacity (peak oxygen consumption, VO2) after CR in surgical compared to non-surgical cardiac patients. Methods Elderly patients (?65 years) commencing CR after coronary artery bypass grafting, surgical valve replacement (surgery-group), percutaneous coronary intervention, percutaneous valve replacement or without revascularisation (non-surgery group) were included in the prospective multi-center EU-CaRE study. CPETs were performed at start of CR, end of CR and 1-year-follow-up. Logistic models and receiver operating characteristics were used to determine prognostic values of CPET parameters for major adverse cardiac events (MACE). Linear models were performed for change in peak VO2 (start to follow-up) and parameters accounting for the difference between surgery and non-surgery patients were sought. Results 1421 out of 1633 EU-CaRE patients performed a valid CPET at start of CR (age 73±5.4, 81% male). No CPET parameter further improved the receiver operation characteristics significantly beyond the model with only clinical parameters. The higher improvement in peak VO2 (25% vs. 7%) in the surgical group disappeared when adjusted for changes in peak tidal volume and haemoglobin. Conclusion CPET did not improve the prediction of MACE in elderly CR patients. The higher improvement of exercise capacity in surgery patients was mainly driven by restoration of haemoglobin levels and improvement in respiratory function after sternotomy
Fractional Flow Reserve\u2013Guided Deferred Versus Complete Revascularization in Patients With Diabetes Mellitus
To assess the safety and efficacy of deferred versus complete revascularization using a fractional flow reserve (FFR)\u2013guided strategy in patients with diabetes mellitus (DM), we analyzed all DM patients who underwent FFR-guided revascularization from January 1, 2010, to December 12, 2013. Patients were divided into 2 groups: those with 651 remaining FFR-negative (>0.80) medically treated lesions [FFR( 12)MT] and those with only FFR-positive lesions ( 640.80) who underwent complete revascularization [FFR(+)CR] and were followed until July 1, 2015. The primary end point was the incidence of major adverse cardiovascular events (MACE), a composite of death, myocardial infarction (MI), target lesion (FFR assessed) revascularization, and rehospitalization for acute coronary syndrome. A total of 294 patients, 205 (69.7%) versus 89 (30.3%) in FFR( 12)MT and FFR(+)CR, respectively, were analyzed. At a mean follow-up of 32.6 \ub1 18.1\ua0months, FFR( 12)MT was associated with higher MACE rate 44.0% versus 26.6% (log-rank p\ua0=\ua00.02, Cox regression\u2013adjusted hazard ratio [HR] 2.01, 95% confidence interval [CI] 1.21 to 3.33, p\ua0<0.01), and\ua0driven by both safety and efficacy end points: death/MI (HR 2.02, 95% CI 1.06 to 3.86, p\ua0= 0.03), rehospitalization for acute coronary syndrome (HR 2.06, 95% CI 1.03 to 4.10, p\ua0= 0.04), and target lesion revascularization (HR 3.38, 95% CI 1.19 to 9.64, p\ua0= 0.02). Previous MI was a strong effect modifier within the FFR( 12)MT group (HR 1.98, 95% CI 1.26 to 3.13, p <0.01), whereas this was not the case in the FFR(+)CR group (HR 0.66, 95% CI 0.27 to 1.62, p\ua0= 0.37). Significant interaction for MACE was present between FFR groups and previous MI (p\ua0= 0.03). In conclusion, in patients with DM, particularly those\ua0with previous MI, deferred revascularization is associated with poor medium-term outcomes. Combining FFR with imaging techniques may be required to guide our treatment strategy in these patients with high-risk, fast-progressing atherosclerosis
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