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Biology subjects

Patterson, S.

Publications and source records attributed to Patterson, S..

9 recordsLinked to original sources

Cytokines of the Interleukin-1 superfamily and Interleukin-6 are associated with neuroinflammation and brain injury in Herpes Simplex Virus Encephalitis

Herpes simplex virus (HSV) is the leading cause of encephalitis, with high rates of morbidity and mortality. Dysregulated immune responses have been associated with poor outcomes in small series, driving interest in immunotherapies. However, the key mediators of neuropathology, their cellular sources, and responsiveness to corticosteroid treatment remain unknown. We present findings from an RCT of dexamethasone in 55 adults with HSV encephalitis, alongside a representative murine model. Clinical severity and adverse outcomes were associated with neuroglial injury biomarkers (GFAP, tau, UCH-L1), increased cerebral oedema on MRI, and higher IL-1RA, IL-18, and IL-6. These mediators were more abundant in matched CSF than serum, and were not reduced by dexamethasone. In the model, neurons, astrocytes and microglia robustly expressed IL-1 and IL-6, supporting their CNS origin. These findings identify IL-1 and IL-6 signalling as key drivers of immunopathology in HSV encephalitis and potential therapeutic targets to mitigate neuroinflammation and improve outcomes. FundingNational Institute for Health and Care Research (grant number 12/205/28).

neuroscience↗

Transcriptomic analysis reveals immune signatures associated with specific cutaneous manifestations of lupus in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) presents with diverse heterogenous cutaneous manifestations. However, the molecular and immunologic pathways driving specific cutaneous manifestations of SLE are poorly understood. Here, we leverage transcriptomics from a large well-phenotyped longitudinal cohort of SLE patients to map molecular pathways linked to ten distinct SLE-related rashes. Through whole blood and immune cell-sorted bulk RNA sequencing, we identified immune signatures specific to cutaneous subtypes of SLE. Subacute cutaneous lupus (SCLE) exhibited broad upregulation of interferon, TNF-, and IL6-JAK-STAT3 pathways suggesting potential unique therapeutic responses to JAK and type I interferon inhibition. While interferon signaling is prominent in SCLE, discoid lupus, and acute lupus, it is unexpectedly attenuated in patients with skin and mucosal ulcers. Pathway and cell-type enrichment analysis revealed unexpected roles for CD14+ monocytes in photosensitivity of SLE and NK cells in alopecia, mucosal ulceration, and livedo reticularis. These findings illuminate the immune heterogeneity of rashes in SLE, highlighting subtype-specific mechanistic targets, and presenting opportunities for precision therapies for SLE-associated skin phenotypes.

bioinformatics↗

Cell-Specific Transposable Element Gene Expression Analysis Identifies Associations with Systemic Lupus Erythematosus Phenotypes

There is an established yet unexplained link between interferon (IFN) and systemic lupus erythematosus (SLE). The expression of sequences derived from transposable elements (TEs) may contribute to production of type I IFNs and generation of autoantibodies. We profiled cell-sorted RNA-seq data (CD4+ T cells, CD14+ monocytes, CD19+ B cells, and NK cells) from PBMCs of 120 SLE patients and quantified TE expression identifying 27,135 TEs. We tested for differential TE expression across 10 SLE phenotypes including autoantibody production and disease activity and discovered 731 differentially expressed (DE) TEs whose effects were mostly cell-specific and phenotype-specific. DE TEs were enriched for specific families and viral genes encoded in TE sequences. Increased expression of DE TEs was associated with genes involved in antiviral activity such as LY6E, ISG15, TRIM22 and pathways such as interferon signaling. These findings suggest that expression of TEs contributes to activation of SLE-related mechanisms in a cell-specific manner, which can impact disease diagnostics and therapeutics.

molecular biology↗

In vivo physiology of foveal retinal ganglion cells in Macaca fascicularis

The primate fovea is specialized for high acuity chromatic vision, with the highest density of cone photoreceptors and a disproportionately large representation in visual cortex. The unique visual properties conferred by the fovea are conveyed to the brain by retinal ganglion cells, the somas of which lie at the margin of the foveal pit. Microelectrode recordings of these centermost retinal ganglion cells have been challenging due to the fragility of the fovea in the excised retina. Here we overcome this challenge by combining high resolution fluorescence adaptive optics ophthalmoscopy with calcium imaging to optically record functional responses of foveal retinal ganglion cells in the living eye. We use this approach to study the chromatic responses and spatial transfer functions of retinal ganglion cells using spatially uniform fields modulated in different directions in color space and monochromatic drifting gratings. We recorded from over 350 cells across three Macaca fascicularis primates over a time period of weeks to months. We find that the majority of the L vs. M cone opponent cells serving the most central foveolar cones have spatial transfer functions that peak at high spatial frequencies (20-40 c/deg), reflecting strong surround inhibition that sacrifices sensitivity at low spatial frequencies but preserves the transmission of fine detail in the retinal image. In addition, we fit to the drifting grating data a detailed model of how ganglion cell responses draw on the cone mosaic to derive receptive field properties of L vs. M cone opponent cells at the very center of the foveola. The fits are consistent with the hypothesis that foveal midget ganglion cells are specialized to preserve information at the resolution of the cone mosaic. By characterizing the functional properties of retinal ganglion cells in vivo through adaptive optics, we characterize the response characteristics of these cells in situ.

neuroscience↗

Dynamically regulated Focal adhesions coordinate endothelial cell remodelling in developing vasculature

The assembly of a mature vascular network involves the coordinated control of cell shape changes to regulate morphogenesis of a complex vascular network. Cellular changes include a process of endothelial cell (EC) elongation which is essential for establishing appropriately sized lumens during vessel maturation1-3. However how EC elongation is dynamically regulated in vivo is not fully understood since live monitoring of this event can be challenging in animal models. Here, we utilise the live imaging capacity of the zebrafish to explore how integrin adhesion complexes, known as Focal Adhesions (FAs), control EC dynamics in live flow pressured vasculature. To do this, we generated a zebrafish mutant, deficient for the integrin adaptor protein Talin1. Notably, unlike the severe cardiovascular defects that arise in Talin1 knockout mice4, vasculogenesis still occurs normally talin1 mutants and cardiac output remains sufficient up to two days post fertilisation (dpf). This allowed us to uncouple primary roles for FAs in ECs during subsequent morphogenesis events, including angiogenesis and vessel remodelling, without interference of secondary effects that might occur due to systemic vessel failure or loss of blood flow. We further established a FA marker line, expressing endothelial Vinculin-eGFP, and demonstrated that FAs are lost in our talin1 mutants. This Vinculin transgene represents the first in vivo model to monitor endothelial FA dynamics. Loss of FAs in talin1 mutants, leads to compromised F-actin rearrangements, which perturb EC elongation and cell-cell junction linearisation during vessel remodelling. Chemical induction of actin polymerisation can restore these cellular phenotypes, suggesting a recovery of actin rearrangements that are sufficient to allow cell and junction shape changes. Together, we have identified that FAs are essential for active guidance of EC elongation and junction linearisation in flow pressured vessels. These observations can explain the severely compromised vessel beds, haemorrhage and vascular leakage that has been observed in mouse models that lack integrin signalling4-8.

cell biology↗

Gypenosides modulate NCX calcium flux, insulin secretion and cytoprotection in BRIN-BD11 pancreatic β-cells

Gypenosides are saponins extracted from the plant Gynostemma pentaphyllum, suggested to have antidiabetic and anti-obesity potential. However, its mechanism of action is not fully understood. The present study aimed to investigate the cytoprotective and insulin stimulatory effects of gypenosides using the rat BRIN-BD11 {beta}-cell line. Gypenosides provided a significant cytoprotective effect against palmitate-, peroxide- and cytokine-induced cytotoxicity, with upregulation of antioxidant genes Nrf2, Cat, Sod1, and Gpx1. Acutely, gypenosides enhanced intracellular calcium ([Ca2+]i) and insulin secretion in a dose-dependent manner. The presence of the sodium/calcium exchanger (NCX) reverse mode inhibitor SN-6 blocked the gypenosides mediated increase in [Ca2+]I but not the insulin secretion. These findings indicate that gypenosides may enhance [Ca2+]i by activating the reverse mode of NCX channels and a possible calcium-independent mechanism involved in their insulin secretion. Gypenosides also upregulate the antioxidant gene expression and protect against oxidative stress and lipotoxicity, providing the rationale for their observed antidiabetic actions.

pharmacology and toxicology↗

Effects of gypenosides on enteroendocrine L-cell function and GLP-1 secretion

Glucagon-like peptide 1 (GLP-1) is an incretin hormone produced in gut L-cells, which regulates postprandial glucose-dependent insulin secretion, also known as the incretin effect. GLP-1 secretion may be reduced in type 2 diabetes mellitus, impacting on glycaemic regulation. Thus, methods to enhance endogenous GLP-1 secretion by use of natural GLP-1 secretagogues may improve glucose control in diabetes. Gypenosides (GYP) extracted from the plant Gynostemma Pentaphyllum (Jiaogulan) are known for their glucose-lowering effects both in vitro and in vivo, although their effect on GLP-1 secretion is unknown. Our results showed that GYP enhanced cell viability and significantly upregulated antioxidant gene Nrf2, Cat and Ho-1 expression. GYP did not affect glucokinase expression but downregulated proglucagon gene expression over 24h, although, cellular GLP-1 content was unchanged. Prohormone convertase 1 (Pcsk1) gene expression was unchanged by GYP over 24h, although protein levels were significantly downregulated, while prohormone convertase 2 (Pcsk2) mRNA and protein levels were significantly upregulated. Acute exposure to gypenosides enhanced calcium uptake and GLP-1 release from GLUTag cells both at low and high glucose concentrations. These results suggest that anti-diabetic properties of gypenosides are partly linked to their ability to stimulate GLP-1 secretion. Gypenosides enhance antioxidant gene expression and may protect L-cells from excess oxidative stress.

pharmacology and toxicology↗

Cytoprotective effects of combination of gypenosides and Costus pictus D.Don extract in BRIN-BD11 β-cells

Ethnopharmacological RelevanceGypenosides and Costus pictus D.Don are used as an anti-diabetic herbal remedy in China and India respectively. However, the synergistic effect of these two extracts on {beta}-cell protection is not yet elucidated. IntroductionIn Type 2 diabetes mellitus (T2DM), pro-inflammatory cytokines and lipotoxicity are known causes of pancreatic {beta}-cell dysfunction and impaired insulin secretion and eventually {beta}-cell death. Thus, any cytoprotective drug supplements can protect the {beta}-cell and may help in T2DM treatment. Gypenosides, extracted from the Chinese medicinal herb Gynostemma pentaphyllum and the leaf extract from an Indian medicinal herb Costus pictus D. Don are used in traditional medicine due to their insulin secretory properties. In our previous studies, both extracts have shown significant cytoprotective effects in insulin-secreting BRIN-BD11 cells. In the present study, we aim to investigate the synergistic effects of a combination of these extracts on BRIN-BD11 {beta}-cell protection. MethodsCombination of extracts was prepared by adding Gypenosides with Costus pictus at 2:1 to a concentration of 18.75mg/ml. Cell viability was determined by MTT assay following treatment with combination and/or palmitate and cytokine cocktail for 24-48h. Following 24h treatment, proliferation was measured by Ki67 staining and cytoprotective gene expression was quantified by qPCR. ResultsCombination treatment of 25{micro}g/ml enhanced cell viability both at 24h (n=8; P<0.05) and 48h (n=8; P<0.0001) treatment. Over 24h, combination treatment (25&12.5 {micro}g/ml) showed a significant protective effect against 125{micro}M and 250{micro}M palmitate induced (P<0.0001) and cytokine cocktail-(TNF 1000U, IL-1{beta} 50U & IFN{gamma} 1000U) (P<0.0001 & P<0.01 respectively) induced toxicity. Combination treatment over 24h increased expression of antioxidant genes Nrf2 (P<0.001), Cat (P<0.001) and Sod1 (P<0.05) along with pro-proliferative Erk1 (P<0.01) while pro-inflammatory Nfkb1 expression was reduced(P<0.001). ConclusionThe results suggest that a combination of gypenosides and costus pictus may protect {beta}-cells against inflammatory cytokines and lipotoxicity caused by saturated free fatty acids associated with obesity and diabetes.

pharmacology and toxicology↗

A harmonized meta-knowledgebase of clinical interpretations of cancer genomic variants

Precision oncology relies on the accurate discovery and interpretation of genomic variants to enable individualized diagnosis, prognosis, and therapy selection. We found that knowledgebases containing clinical interpretations of somatic cancer variants are highly disparate in interpretation content, structure, and supporting primary literature, impeding consensus when evaluating variants and their relevance in a clinical setting. With the cooperation of experts of the Global Alliance for Genomics and Health (GA4GH) and six prominent cancer variant knowledgebases, we developed a framework for aggregating and harmonizing variant interpretations to produce a meta-knowledgebase of 12,856 aggregate interpretations covering 3,437 unique variants in 415 genes, 357 diseases, and 791 drugs. We demonstrated large gains in overlap between resources across variants, diseases, and drugs as a result of this harmonization. We subsequently demonstrated improved matching between a patient cohort and harmonized interpretations of potential clinical significance, observing an increase from an average of 33% per individual knowledgebase to 56% in aggregate. Our analyses illuminate the need for open, interoperable sharing of variant interpretation data. We also provide an open and freely available web interface (search.cancervariants.org) for exploring the harmonized interpretations from these six knowledgebases.

bioinformatics↗