Biology subjects

Weston, C. J.

Publications and source records attributed to Weston, C. J..

4 recordsLinked to original sources

bioRxiv2024

Distinct circulating monocytes up-regulate CD52 and sustain innate immune function in patients with cirrhosis unless acute decompensation emerges

Background & AimsInfectious complications determine the prognosis of cirrhosis patients. Their infection susceptibility relates to the development of immuneparesis, a complex interplay of different immunosuppressive cells and soluble factors. Mechanisms underlying the dynamics of immuneparesis of innate immunity remain inconclusive. We aimed to dissect the heterogeneity of circulating monocyte states in different cirrhosis stages, and pursued the function of selected differentially expressed (DE) genes. MethodsWe systematically investigated circulating monocytes in health, compensated and not-acutely decompensated (NAD) cirrhosis using single cell RNA sequencing. Selective genes were confirmed by flow cytometry and diverse functional assays on monocytes ex vivo. ResultsWe identified seven monocyte clusters. Their abundances varied between cirrhosis stages, confirming previously reported changes i.e. reduction in CD14lowCD16++ and emergence of M-MDSC in advanced stages. DE genes between health and disease and among stages were detected, including for the first time CD52. CD52-expression on monocytes significantly enhanced throughout compensated and NAD cirrhosis. Heretofore the biological significance of CD52-expression on monocytes remained unknown. CD52highCD14+CD16highHLA-DRhigh monocytes in patients with cirrhosis revealed a functional phenotype of active phagocytes with enhanced migratory potential, increased cytokine production, but poor T cell activation. Following acute decompensation (AD), CD52 was cleaved by elevated phospholipase C (PLC), and soluble CD52 (sCD52) was detected in the circulation. Inhibition and cleavage of CD52 significantly suppressed monocyte functions ex vivo and in vitro, and the predominance of immunosuppressive CD52low circulating monocytes in patients with AD was associated with infection and low transplant-free survival. ConclusionCD52 may represent a biologically relevant target for future immunotherapy. Stabilising CD52 may enhance monocyte functions and infection control in the context of cirrhosis, guided by sCD52/PLC as biomarkers indicating immuneparesis. Lay summaryRecurrent infections are a major cause of death in patients with liver cirrhosis. A fundamental understanding of the mechanisms that suppress immune responses in patients with cirrhosis is lacking, but required for the development of strategies to restore innate immunity in cirrhosis patients and prevent infection. The current study identified a novel marker for deficient immune responses and a potential target for such a future immune-based therapy. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=134 SRC="FIGDIR/small/587894v1_ufig1.gif" ALT="Figure 1"> View larger version (40K): org.highwire.dtl.DTLVardef@1a42b1borg.highwire.dtl.DTLVardef@10a0df2org.highwire.dtl.DTLVardef@1199087org.highwire.dtl.DTLVardef@15fb074_HPS_FORMAT_FIGEXP M_FIG O_FLOATNOGraphical AbstractC_FLOATNO scRNA-seq identified seven circulating monocyte states, changing in cirrhosis patients at different stages of disease. Circulating monocytes overexpress CD52 in cirrhosis, but are absent in AD/ACLF due to PLC. CD52-expressing monocytes show high capability for phagocytosis, cytokine production, adhesion and migration potential and T cell suppression. Created with BioRender.com C_FIG

immunology↗

bioRxiv2024

Evaluation of Gremlin-1 as a therapeutic target in metabolic dysfunction-associated steatohepatitis

Gremlin-1 has been implicated in liver fibrosis in metabolic dysfunction-associated steatohepatitis (MASH) via inhibition of bone-morphogenetic protein (BMP) signalling and has thereby been identified as a potential therapeutic target. Using rat in vivo and human in vitro and ex vivo model systems of MASH fibrosis, we show that neutralisation of Gremlin-1 activity with monoclonal therapeutic antibodies does not reduce liver inflammation or liver fibrosis. Still, Gremlin-1 was upregulated in human and rat MASH fibrosis, but expression was restricted to a small subpopulation of COL3A1/THY1+ myofibroblasts. Lentiviral overexpression of Gremlin-1 in LX-2 cells and primary hepatic stellate cells led to changes in BMP-related gene expression, which did not translate to increased fibrogenesis. Furthermore, we show that Gremlin-1 binds to heparin with high affinity, which prevents Gremlin-1 from entering systemic circulation, prohibiting Gremlin-1-mediated organ crosstalk. Overall, our findings suggest a redundant role for Gremlin-1 in the pathogenesis of liver fibrosis, which is unamenable to therapeutic targeting.

pathology↗

bioRxiv2023

Multimodal decoding of human liver regeneration

The liver has a unique ability to regenerate1,2, however in the setting of acute liver failure (ALF) this regenerative capacity is often overwhelmed and emergency liver transplantation is the only curative option3-5. To advance our understanding of human liver regeneration and to inform design of pro-regenerative therapies, we use paired single-nuclei RNA sequencing (snRNA-seq) combined with spatial profiling of healthy and ALF explant human livers to generate the first single-cell, pan-lineage atlas of human liver regeneration. We uncover a novel ANXA2+ migratory hepatocyte subpopulation which emerges during human liver regeneration, and a corollary migratory hepatocyte subpopulation in a mouse model of acetaminophen (APAP)-induced liver regeneration. Importantly, interrogation of necrotic wound closure and hepatocyte proliferation across multiple timepoints following APAP-induced liver injury in mice demonstrates that wound closure precedes hepatocyte proliferation. 4-D intravital imaging of APAP-induced mouse liver injury identifies motile hepatocytes at the edge of the necrotic area, enabling collective migration of the hepatocyte sheet to effect wound closure. Depletion of hepatocyte ANXA2 expression reduces HGF-induced human and mouse hepatocyte migration in vitro, and abrogates necrotic wound closure following APAP-induced mouse liver injury. Taken together, our work dissects unanticipated aspects of liver regeneration, demonstrating an uncoupling of wound closure and hepatocyte proliferation and uncovering a novel migratory hepatocyte subpopulation which mediates wound closure following liver injury. Therapies designed to promote rapid reconstitution of normal hepatic microarchitecture and reparation of the gut-liver barrier may open up new areas of therapeutic discovery in regenerative medicine.

cell biology↗

bioRxiv2019

Resolving the fibrotic niche of human liver cirrhosis using single-cell transcriptomics

Currently there are no effective antifibrotic therapies for liver cirrhosis, a major killer worldwide. To obtain a cellular resolution of directly-relevant pathogenesis and to inform therapeutic design, we profile the transcriptomes of over 100,000 primary human single cells, yielding molecular definitions for the major non-parenchymal cell types present in healthy and cirrhotic human liver. We uncover a novel scar-associated TREM2+CD9+ macrophage subpopulation with a fibrogenic phenotype, that has a distinct differentiation trajectory from circulating monocytes. In the endothelial compartment, we show that newly-defined ACKR1+ and PLVAP+ endothelial cells expand in cirrhosis and are topographically located in the fibrotic septae. Multi-lineage ligand-receptor modelling of specific interactions between the novel scar-associated macrophages, endothelial cells and collagen-producing myofibroblasts in the fibrotic niche, reveals intra-scar activity of several major pathways which promote hepatic fibrosis. Our work dissects unanticipated aspects of the cellular and molecular basis of human organ fibrosis at a single-cell level, and provides the conceptual framework required to discover rational therapeutic targets in liver cirrhosis.

immunology↗