Biology subjects

Hussey, S.

Publications and source records attributed to Hussey, S..

4 recordsLinked to original sources

bioRxiv2026

Targeting redox imbalance through Nrf2 activation in the inflamed coeliac duodenum.

Coeliac Disease (CeD) is a chronic gastrointestinal inflammatory disease initiated by dietary gluten in genetically predisposed individuals. While the inflammatory processes which drive tissue destruction in the coeliac duodenum have been extensively characterised, an increased oxidative stress (OS) response has also been suggested to contribute to CeD pathogenesis. However, the precise mechanisms which regulate OS in the coeliac mucosa and whether they impact inflammation remain ill defined. The master anti-oxidant transcriptional regulator Nuclear factor erythroid 2-related factor 2 (Nrf2), and its inhibitor, Kelch like ECH-associated protein 1 (Keap1) have been implicated in chronic gastrointestinal inflammatory diseases, such as ulcerative colitis but have been largely unexplored in the context of CeD. To investigate redox balance in the CeD duodenum, we utilised single cell transcriptomics to assess overall OS and cytoprotective Nrf2 activation across cell subsets in duodenal biopsies from CeD patients. OS induced gene expression was broadly increased across multiple cell subsets in the CeD mucosa. Simultaneously, specific markers of Nrf2 activation were decreased in cell subtypes central to pathogenesis of CeD, including activated CD4+ T cells and intraepithelial T lymphocytes, indicating a distinct redox imbalance in these cells. Furthermore, pharmacological activation of Nrf2 significantly decreased gliadin induced IFNG expression in CeD duodenal biopsies. Taken together, our findings demonstrate that redox imbalance represents a therapeutic opportunity for the modulation of proinflammatory responses that drive the pathogenesis of CeD.

immunology↗

bioRxiv2025

Immune signaling mediates stromal changes to support epithelial reprogramming in Celiac duodenum

Coeliac Disease (CeD) is a chronic autoimmune disorder affecting 0.5-1% of the general population with a wide geographical distribution. Despite recent efforts to deeply phenotype gluten-specific immune activation at the single cell level, recent clinical studies targeting gluten degradation and other immune tolerance mechanisms have been unsuccessful. To this end, a deeper understanding of immune and non-immune cellular dynamics and interactions are required to characterize tissue-specific mechanisms responsible for CeD pathogenesis, repair, and resolution. Here, we assembled the most comprehensive scRNAseq dataset in Coeliac Disease to date, including 203,555 cells across 21 active CeD and 11 control duodenal samples. Compared to control duodenum, CeD was characterized by single cell differential changes in abundance, gene expression and cell-cell interactions across cellular compartments. In the immune compartments, CeD samples showed expected increases in plasma cell abundance and shifts toward type 1 effector biology (e.g., increase in cycling CD8pos, {gamma}{delta} T cells and IFNG transcriptional shifts) and Tfh-related biology (e.g., increases in IL21 signaling to effector T cells). In addition, activated myeloid subsets, including DC2 and monocytes, were increased in disease and were characterized by increased pro-inflammatory pathway expression, including IL-1{beta}. Non-immune compartments showed increased stem/crypt and secretory enterocytes in CeD samples with a decrease in absorptive enterocytes, reflecting the villus atrophy and crypt hyperplasia hallmarks of CeD epithelial dysfunction. Accompanying the epithelial changes, distinct changes in stromal populations were identified, particularly with increases in abundance and transcriptional activity of NRG1 and SMOC2 fibroblasts. Cell-cell interaction analysis across multiple cellular compartments proposed a distinct increased role of fibroblasts to support the epithelial reprogramming of the increased stem/crypt epithelial fraction in CeD, mediated by myeloid derived IL-1{beta} signal and lymphoid-derived IFN-{gamma}. This dataset reveals a previously unknown role for T-myeloid-stromal-epithelial cell communication in CeD, highlighting key mechanisms of the tissue-level cellular dynamics in response to gluten ingestion.

immunology↗

bioRxiv2024

Tissue factor-dependent colitogenic CD4+ T cell thrombogenicity is regulated by activated protein C signalling.

Inflammatory bowel disease (IBD) patients experience up to 6-fold increased risk of venous thromboembolism (VTE) compared to the general population, although the mechanistic basis for this increased risk remains poorly defined. We found that colitogenic CD4+ T cells express tissue factor (TF) and promote rapid TF-dependent plasma thrombin generation in T cell-dependent calibrated automated thrombinography assays. Furthermore, we identified the presence of TF+CD4+CD3+ T cells in the colons of both mice with colitis and paediatric IBD patients during active disease. TF is typically expressed in an encrypted state and requires decryption for optimal procoagulant activity. Notably, flow cytometric analysis demonstrated that activated CD4+ T cells express significantly increased acid sphingomyelinase and protein disulphide isomerase, critical mediators for TF decryption, on their cell membrane compared to naive T cells. The protein C (PC) pathway is an important regulator of TF-mediated thrombin generation. Pertinently, pre-clinical studies suggest an important role for diminished PC pathway activity in IBD pathophysiology. To understand how this process might be regulated, we performed meta-transcriptomic and gene expression analysis of IBD patient gut biopsy tissue, identifying dysregulated expression of genes involved in the regulation of coagulation, including PC (PROC) and its receptor (EPCR; PROCR). Subsequent functional studies revealed that activated protein C (APC) signalling reduced colitogenic T cell generation and activity, potently impaired TF decryption and significantly reduced T cell-mediated thrombin generation and clot formation. These data identify TF-mediated colitogenic T cell thrombogenicity and demonstrate a new role for APC signalling in regulating T cell thrombo-inflammatory activity.

immunology↗

bioRxiv2023

GLYCOLYTIC REPROGRAMMING FUELS MYELOID CELL-DRIVEN HYPERCOAGULABILITY

BackgroundMyeloid cell metabolic reprogramming is a hallmark of inflammatory disease, however, its role in inflammation-induced hypercoagulability is poorly understood. Objective/MethodsUsing novel myeloid cell-based global haemostasis assays and murine models of immunometabolic disease, we evaluated the role of inflammation-associated metabolic reprogramming in regulating blood coagulation. ResultsGlycolysis was essential for enhanced activated myeloid cell tissue factor expression and decryption, driving increased cell-dependent thrombin generation in response to inflammatory challenge. Similarly, inhibition of glycolysis enhanced activated macrophage fibrinolytic activity via reduced plasminogen activator inhibitor 1 (PAI-1)-activity. Macrophage polarisation or activation markedly increased endothelial protein C receptor (EPCR) expression on monocytes and macrophages, leading to increased myeloid cell-dependent protein C activation. Importantly, inflammation-dependent EPCR expression on tissue-resident macrophages was also observed in vivo. Adipose tissue macrophages from obese mice fed a high-fat diet exhibited significantly enhanced EPCR expression and APC generation compared to macrophages isolated from the adipose tissue of healthy mice. Similarly, the induction of colitis in mice prompted infiltration of EPCR+ innate myeloid cells within inflamed colonic tissue that were absent from the intestinal tissue of healthy mice. ConclusionCollectively, this study identifies immunometabolic regulation of myeloid cell hypercoagulability, opening new therapeutic possibilities for targeted mitigation of thrombo-inflammatory disease. ESSENTIALSO_LIInflammation-mediated glycolytic reprogramming enables myeloid cell-induced hypercoagulability and antifibrinolytic activity. C_LIO_LI2-Deoxy-D-glucose (2-DG) inhibits the expression of transcription factors necessary for inflammation-induced procoagulant gene expression. C_LIO_LIMyeloid cell membrane regulation of tissue factor procoagulant activity is glycolysis-dependent. C_LIO_LIActivation of myeloid innate immunity dysregulates activated protein C anticoagulant pathway activity. C_LI

immunology↗