130 research outputs found

    Alcohol-preferring rats show decreased corticotropin-releasing hormone-2 receptor expression and differences in HPA activation compared to alcohol-nonpreferring rats

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    BACKGROUND: Corticotropin-releasing hormone (CRH) and urocortins (UCNs) bind to corticotropin-releasing hormone type 2 receptor (CRF2 receptor ), a Gs protein-coupled receptor that plays an important role in modulation of anxiety and stress responses. The Crhr2 gene maps to a quantitative trait locus (QTL) for alcohol preference on chromosome 4 previously identified in inbred alcohol-preferring (iP) and-nonpreferring (iNP) F2 rats. METHODS: Real-time polymerase chain reaction was utilized to screen for differences in Crhr2 mRNA expression in the central nervous system (CNS) of male iP and iNP rats. DNA sequence analysis was then performed to screen for polymorphism in Crhr2 in order to identify genetic variation, and luciferase reporter assays were then applied to test their functional significance. Next, binding assays were used to determine whether this polymorphism affected CRF2 receptor binding affinity as well as CRF2 receptor density in the CNS. Finally, social interaction and corticosterone levels were measured in the P and NP rats before and after 30-minute restraint stress. RESULTS: Crhr2 mRNA expression studies found lower levels of Crhr2 mRNA in iP rats compared to iNP rats. In addition, DNA sequencing identified polymorphisms in the promoter region, coding region, and 3'-untranslated region between the iP and iNP rats. A 7 bp insertion in the Crhr2 promoter of iP rats altered expression in vitro as measured by reporter assays, and we found that CRF2 receptor density was lower in the amygdala of iP as compared to iNP rats. Male P rats displayed decreased social interaction and significantly higher corticosterone levels directly following 30-minute restraint when compared to male NP rats. CONCLUSIONS: This study identified Crhr2 as a candidate gene of interest underlying the chromosome 4 QTL for alcohol consumption that was previously identified in the P and NP model. Crhr2 promoter polymorphism is associated with reduced mRNA expression in certain brain regions, particularly the amygdala, and lowered the density of CRF2 receptor in the amygdala of iP compared to iNP rats. Together, these differences between the animals may contribute to the drinking disparity as well as the anxiety differences of the P and NP rats

    Transcriptomic analysis of cutaneous squamous cell carcinoma reveals a multi-gene prognostic signature associated with metastasis

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    Background: Metastasis of cutaneous squamous cell carcinoma (cSCC) is uncommon. Current staging methods are reported to have sub-optimal performances in metastasis prediction. Accurate identification of patients with tumours at high risk of metastasis would have a significant impact on management.Objective: To develop a robust and validated gene expression profile (GEP) signature for predicting primary cSCC metastatic risk using an unbiased whole transcriptome discovery-driven approach.Methods: Archival formalin-fixed paraffin-embedded primary cSCC with perilesional normal tissue from 237 immunocompetent patients (151 non-metastasising and 86 metastasising) were collected retrospectively from four centres. TempO-seq was used to probe the whole transcriptome and machine learning algorithms were applied to derive predictive signatures, with a 3:1 split for training and testing datasets.Results: A 20-gene prognostic model was developed and validated, with an accuracy of 86.0%, sensitivity of 85.7%, specificity of 86.1%, and positive predictive value of 78.3% in the testing set, providing more stable, accurate prediction than pathological staging systems. A linear predictor was also developed, significantly correlating with metastatic risk.Limitations: This was a retrospective 4-centre study and larger prospective multicentre studies are now required.Conclusion: The 20-gene signature prediction is accurate, with the potential to be incorporated into clinical workflows for cSCC

    Impaired expression of metallothioneins contributes to allergen-induced inflammation in patients with atopic dermatitis

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    Regulation of cutaneous immunity is severely compromised in inflammatory skin disease. To investigate the molecular crosstalk underpinning tolerance versus inflammation in atopic dermatitis, we utilise a human in vivo allergen challenge study, exposing atopic dermatitis patients to house dust mite. Here we analyse transcriptional programmes at the population and single cell levels in parallel with immunophenotyping of cutaneous immunocytes revealed a distinct dichotomy in atopic dermatitis patient responsiveness to house dust mite challenge. Our study shows that reactivity to house dust mite was associated with high basal levels of TNF-expressing cutaneous Th17 T cells, and documents the presence of hub structures where Langerhans cells and T cells co-localised. Mechanistically, we identify expression of metallothioneins and transcriptional programmes encoding antioxidant defences across all skin cell types, that appear to protect against allergen-induced inflammation. Furthermore, single nucleotide polymorphisms in the MTIX gene are associated with patients who did not react to house dust mite, opening up possibilities for therapeutic interventions modulating metallothionein expression in atopic dermatitis

    Effect of altered haemodynamics on the developing mitral valve in chick embryonic heart

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    Intracardiac haemodynamics is crucial for normal cardiogenesis, with recent evidence showing valvulogenesis is haemodynamically dependent and inextricably linked with shear stress. Although valve anomalies have been associated with genetic mutations, often the cause is unknown. However, altered haemodynamics have been suggested as a pathogenic contributor to bicuspid aortic valve disease. Conversely, how abnormal haemodynamics impacts mitral valve development is still poorly understood. In order to analyse altered blood flow, the outflow tract of the chick heart was constricted using a ligature to increase cardiac pressure overload. Outflow tract-banding was performed at HH21, with harvesting at crucial valve development stages (HH26, HH29 and HH35). Although normal valve morphology was found in HH26 outflow tract banded hearts, smaller and dysmorphic mitral valve primordia were seen upon altered haemodynamics in histological and stereological analysis at HH29 and HH35. A decrease in apoptosis, and aberrant expression of a shear stress responsive gene and extracellular matrix markers in the endocardial cushions were seen in the chick HH29 outflow tract banded hearts. In addition, dysregulation of extracellular matrix (ECM) proteins fibrillin-2, type III collagen and tenascin were further demonstrated in more mature primordial mitral valve leaflets at HH35, with a concomitant decrease of ECM cross-linking enzyme, transglutaminase-2. These data provide compelling evidence that normal haemodynamics are a prerequisite for normal mitral valve morphogenesis, and abnormal blood flow could be a contributing factor in mitral valve defects, with differentiation as a possible underlying mechanism

    Epithelial damage and tissue γδ T cells promote a unique tumor-protective IgE response

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    IgE is an ancient and conserved immunoglobulin isotype with potent immunological function. Nevertheless, the regulation of IgE responses remains an enigma, and evidence of a role for IgE in host defense is limited. Here we report that topical exposure to a common environmental DNA-damaging xenobiotic initiated stress surveillance by γδTCR+ intraepithelial lymphocytes that resulted in class switching to IgE in B cells and the accumulation of autoreactive IgE. High-throughput antibody sequencing revealed that γδ T cells shaped the IgE repertoire by supporting specific variable-diversity-joining (VDJ) rearrangements with unique characteristics of the complementarity-determining region CDRH3. This endogenous IgE response, via the IgE receptor FcξRI, provided protection against epithelial carcinogenesis, and expression of the gene encoding FcξRI in human squamous-cell carcinoma correlated with good disease prognosis. These data indicate a joint role for immunosurveillance by T cells and by B cells in epithelial tissues and suggest that IgE is part of the host defense against epithelial damage and tumor development

    International Consensus Statement on Rhinology and Allergy: Rhinosinusitis

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    Background: The 5 years since the publication of the first International Consensus Statement on Allergy and Rhinology: Rhinosinusitis (ICAR‐RS) has witnessed foundational progress in our understanding and treatment of rhinologic disease. These advances are reflected within the more than 40 new topics covered within the ICAR‐RS‐2021 as well as updates to the original 140 topics. This executive summary consolidates the evidence‐based findings of the document. Methods: ICAR‐RS presents over 180 topics in the forms of evidence‐based reviews with recommendations (EBRRs), evidence‐based reviews, and literature reviews. The highest grade structured recommendations of the EBRR sections are summarized in this executive summary. Results: ICAR‐RS‐2021 covers 22 topics regarding the medical management of RS, which are grade A/B and are presented in the executive summary. Additionally, 4 topics regarding the surgical management of RS are grade A/B and are presented in the executive summary. Finally, a comprehensive evidence‐based management algorithm is provided. Conclusion: This ICAR‐RS‐2021 executive summary provides a compilation of the evidence‐based recommendations for medical and surgical treatment of the most common forms of RS

    The role of T cells in cutaneous squamous cell carcinoma

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    Cutaneous squamous cell carcinoma (cSCC) is the most common form of human cancer with metastatic potential. Despite T cells accumulating around cSCCs, these tumours continue to grow and persist. To investigate reasons for the failure of T cells to mount a protective response in cSCC, tumoral T cells were characterised to determine factors responsible for cSCC T cell dysfunction. This thesis focused primarily on regulatory T cells (Tregs, which are considered immunosuppressive) and CD8+ T cells (thought to be responsible for destroying cancer cells) within the population of T cells surrounding cSCCs.Human primary cSCCs contained increased FOXP3+ Treg and CD8+ T cell frequencies compared with corresponding peripheral blood and normal skin. Most tumoral T cells expressed the skin addressin CLA and E-selectin was detected in the majority of peritumoral blood vessels. Functional studies showed that tumoral Tregs suppressed tumoral effector CD4+ and CD8+T cell proliferation and effector T cell interferon-Îł secretion in vitro. OX40 was expressed by higher proportions of tumoral Tregs than other T cells (including CD4+FOXP3- and CD8+ T cells) and increased OX40+ lymphocyte frequencies were observed in primary cSCCs which metastasised compared with primary cSCCs which had not metastasised. Furthermore, in vitro OX40 activation of Treg/CD4+ effector T cell co-cultures enhanced tumoral CD4+ T cell proliferation, thus overcoming Treg suppression.Functional data demonstrated that CD8+ T cells from cSCC were less able to proliferate and produce granzyme B and perforin in vitro than CD8+ T cells from peripheral blood. In addition, IL-2 was produced by fewer T cells in cSCC than in normal skin. The inhibitory receptor PD-1 was expressed by higher proportions of T cells in cSCC than peripheral blood and PD-1 inhibition augmented in vitro tumoral CD8+ T cell proliferation.The results in this thesis highlight that dysfunctional T cell responses are present in cSCC, potentially contributing to ineffective anti-tumour immunity and permitting the development and growth of cSCC. Furthermore, the data in this thesis show that T cells from cSCC can be used for functional assessment of T cell costimulatory/inhibitory antibodies, suggesting this system might be useful as a preclinical tool for investigation of anti-tumour immunotherapies

    Commentary from the Editorial Board. The Warthin-Starry stain for detection of cutaneous melanin: more than a historical curiosity

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    Cutaneous melanin plays an important role in human health and disease; therefore, accurate detection of melanin in skin is essential for reliable investigations on the mechanisms underlying physiological and aberrant pigmentation in skin. Histological visualisation of melanin has most commonly been performed using the Fontana�Masson procedure, originally developed over 100 years ago. By contrast, the Warthin�Starry stain, developed in 1920 for the identification of spirochaetes, was reported in 1980 to be more sensitive and specific for detecting cutaneous melanin than the Fontana�Masson procedure.1 Despite this, the Warthin�Starry stain failed to gain popularity within the field of cutaneous pigmentation research. This commentary will discuss the article by Joly�Tonetti et al.2, who highlight the benefits of the Warthin�Starry method and advocate its use over the Fontana�Masson stain for histological detection of cutaneous melanin
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