John A. Marwick's research while affiliated with Imperial College London and other places

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Publications (55)


Figure 1. ECM and triage assay workflow. (A) Workflow for screening compounds through the ECM and triage assays. (B) Representative images from live cell imaging showing viable cells (top) and cell death (bottom) induced by compound cytotoxicity. (C) Representative high-content images of fibronectin, collagen I+III, and collagen IV staining with composite image. (D) Representative full-plate montage images showing fibronectin staining with or without TGFβ (5 ng/mL) to assess the assay window between minimum and maximum ECM deposition (left) and TGFβ (5 ng/mL)-induced fibronectin staining across a full 384-well plate for coefficient of variance assessment (right).
Figure 2. Primary human lung fibroblast ECM deposition high-content screen. Primary human lung fibroblasts were treated with TGFβ (5 ng/mL) over 7 days in the presence of compounds (1 µM). Plates were denuded of cells and ECM components immunolabeled and imaged on an ImageXpress microscope. (A) Exemplar images of ECM deposition. (B) Principal component (PC) analysis of the quantification of ECM deposition in response to compound treatment. (C) Hit classification using a Euclidean distance from the negative control with a p value cutoff of 0.05 (corrected using the false discovery rate).
Figure 3. Selected hit compound 10-point concentration response in ECM assay. (A) Full-plate montage of fibronectin staining showing 10-point concentration response of 32 compound hits selected from the primary screen. Compound names listed, with the most active compounds highlighted in red. (B) Concentration responses of fibronectin deposition and cytotoxicity for the six compounds that reduced ECM deposition in a concentrated-related manner (see Suppl. Figs. S1-S3 for collagen I+III and IV data). Conc., concentration.
Figure 4. Secondary hit triage assays. (A) Concentration response of the six hit compounds on αSMA expression measured as a percentage of TGFβ (DMSO) positive control (see Suppl. Fig. S4 for representative high-content image). (B) Concentration response of the six hit compounds on fibroblast proliferation as measured by the percentage of the TGFβ (DMSO) positive control. (C) Concentration response of the six hit compounds on fibroblast apoptosis at 48 h postcompound addition as measured by the activation of caspase 3/7 (see Suppl. Fig. S4 for representative image). (D) Concentration response of the six hit compounds on scratch wound healing as measured by wound confluence at 24 h presented as a percentage of DMSO control (see Suppl. Fig. S4 for representative image).
Application of a High-Content Screening Assay Utilizing Primary Human Lung Fibroblasts to Identify Antifibrotic Drugs for Rapid Repurposing in COVID-19 Patients
  • Article
  • Full-text available

June 2021

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84 Reads

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4 Citations

SLAS DISCOVERY Advancing the Science of Drug Discovery

John A. Marwick

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Richard J. R. Elliott

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James Longden

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[...]

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Lung imaging and autopsy reports among COVID-19 patients show elevated lung scarring (fibrosis). Early data from COVID-19 patients as well as previous studies from severe acute respiratory syndrome, Middle East respiratory syndrome, and other respiratory disorders show that the extent of lung fibrosis is associated with a higher mortality, prolonged ventilator dependence, and poorer long-term health prognosis. Current treatments to halt or reverse lung fibrosis are limited; thus, the rapid development of effective antifibrotic therapies is a major global medical need that will continue far beyond the current COVID-19 pandemic. Reproducible fibrosis screening assays with high signal-to-noise ratios and disease-relevant readouts such as extracellular matrix (ECM) deposition (the hallmark of fibrosis) are integral to any antifibrotic therapeutic development. Therefore, we have established an automated high-throughput and high-content primary screening assay measuring transforming growth factor-β (TGFβ)-induced ECM deposition from primary human lung fibroblasts in a 384-well format. This assay combines longitudinal live cell imaging with multiparametric high-content analysis of ECM deposition. Using this assay, we have screened a library of 2743 small molecules representing approved drugs and late-stage clinical candidates. Confirmed hits were subsequently profiled through a suite of secondary lung fibroblast phenotypic screening assays quantifying cell differentiation, proliferation, migration, and apoptosis. In silico target prediction and pathway network analysis were applied to the confirmed hits. We anticipate this suite of assays and data analysis tools will aid the identification of new treatments to mitigate against lung fibrosis associated with COVID-19 and other fibrotic diseases.

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A fluorogenic cyclic peptide for imaging and quantification of drug-induced apoptosis

August 2020

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577 Reads

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50 Citations

Nature Communications

Programmed cell death or apoptosis is a central biological process that is dysregulated in many diseases, including inflammatory conditions and cancer. The detection and quantification of apoptotic cells in vivo is hampered by the need for fixatives or washing steps for non-fluorogenic reagents, and by the low levels of free calcium in diseased tissues that restrict the use of annexins. In this manuscript, we report the rational design of a highly stable fluorogenic peptide (termed Apo-15) that selectively stains apoptotic cells in vitro and in vivo in a calcium-independent manner and under wash-free conditions. Furthermore, using a combination of chemical and biophysical methods, we identify phosphatidylserine as a molecular target of Apo-15. We demonstrate that Apo-15 can be used for the quantification and imaging of drug-induced apoptosis in preclinical mouse models, thus creating opportunities for assessing the in vivo efficacy of anti-inflammatory and anti-cancer therapeutics.


The oncogene Gankyrin is expressed in testicular cancer and contributes to cisplatin sensitivity in embryonal carcinoma cells

November 2019

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147 Reads

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12 Citations

BMC Cancer

Background: Testicular germ cell cancer (TGCC) develops from pre-malignant germ neoplasia in situ (GCNIS) cells. GCNIS originates from fetal gonocytes (POU5F1+/MAGE-A4-), which fail to differentiate to pre-spermatogonia (POU5F1-/MAGE-A4+) and undergo malignant transformation. Gankyrin is an oncogene which has been shown to prevent POU5F1 degradation and specifically interact with MAGE-A4 in hepatocellular carcinoma (HCC) cells. We aimed to investigate the role of Gankyrin in progression from gonocyte to pre-invasive GCNIS and subsequent invasive TGCC. Methods: We determined Gankyrin expression in human fetal testicular tissue (gestational weeks 9-20; n = 38), human adult testicular tissue with active spermatogenesis (n = 9), human testicular tissue with germ cell maturation delay (n = 4), testicular tissue from patients with pre-invasive GCNIS (n = 6), and invasive TGCC including seminoma (n = 6) and teratoma (n = 7). Functional analysis was performed in-vitro by siRNA knock-down of Gankyrin in the NTera2 cells (derived from embryonal carcinoma). Results: Germ cell expression of Gankyrin was restricted to a sub-population of prespermatogonia in human fetal testes. Nuclear Gankyrin was also expressed in GCNIS cells of childhood and adult pre-invasive TGCC patients, and in GCNIS from seminoma and non-seminoma patients. Cytoplasmic expression was observed in seminoma tumour cells and NTera2 cells. Gankyrin knock-down in NTera2 cells resulted in an increase in apoptosis mediated via the TP53 pathway, whilst POU5F1 expression was unaffected. Furthermore, Gankyrin knock-down in NTera2 cells increased cisplatin sensitivity with an increase in cell death (13%, p < 0.05) following Gankyrin knock-down, when compared to cisplatin treatment alone, likely via BAX and FAS. Our results demonstrate that Gankyrin expression changes in germ cells during normal transition from gonocyte to prespermatogonia. In addition, changes in Gankyrin localisation are associated with progression of pre-invasive GCNIS to invasive TGCC. Furthermore, we found that Gankyrin is involved in the regulation of NTera2 cell survival and that a reduction in Gankyrin expression can modulate cisplatin sensitivity. Conclusions: These results suggest that manipulation of Gankyrin expression may reduce the cisplatin dose required for the treatment of TGCC, with benefits in reducing dose-dependent side effects of chemotherapy. Further studies are required in order to assess the effects of modulating Gankyrin on GCNIS/TGCC using in vivo models.


Resolving the fibrotic niche of human liver cirrhosis at single-cell level

November 2019

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2,203 Reads

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987 Citations

Nature

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 human single cells, yielding molecular definitions for non-parenchymal cell types present in healthy and cirrhotic human liver. We uncover a novel scar-associated TREM2⁺CD9⁺ macrophage subpopulation, which expands in liver fibrosis, differentiates from circulating monocytes and is pro-fibrogenic. We also define novel ACKR1⁺ and PLVAP⁺ endothelial cells that expand in cirrhosis, are topographically scar-restricted and enhance leucocyte transmigration. Multi-lineage ligand-receptor modelling of interactions between the novel scar-associated macrophages, endothelial cells and PDGFRα⁺ collagen-producing mesenchymal cells reveals intra-scar activity of several pro-fibrogenic pathways including TNFRSF12A, PDGFR and NOTCH signalling. 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.


Augmentation of Human Monocyte Responses to Lipopolysaccharide by the Protein S and Mer/Tyro3 Receptor Tyrosine Kinase Axis

September 2018

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63 Reads

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18 Citations

The Journal of Immunology

Resolution of the inflammatory response requires coordinated regulation of pro- and anti-inflammatory mediator production, together with clearance of recruited inflammatory cells. Many different receptors have been implicated in phagocytosis of apoptotic cells (efferocytosis), including Mer, a receptor tyrosine kinase that can mediate recognition and subsequent internalization of apoptotic cells. In this manuscript, we examine the expression and function of the Tyro3/Axl/Mer (TAM) family of receptors by human monocytes. We demonstrate that the Mer ligand, protein S, binds to the surface of viable monocytes via phosphatidylserine-dependent and -independent mechanisms. Importantly, we have identified a novel role for receptor tyrosine kinase signaling in the augmentation of monocyte cytokine release in response to LPS. We propose that low-level phosphatidylserine exposure on the plasma membrane of viable monocytes allows protein S binding that leads to TAM-dependent augmentation of proinflammatory cytokine production. Our findings identify a potentially important role for TAM-mediated signaling during the initiation phase of inflammation.






Citations (36)


... 3 In recent years, the automated high-content screening (HCS) platform has been developed and applied to the screening of apoptosis-related drugs and cell biology research. [4][5][6] A rapid and accurate automatic identi¯cation method for apoptosis can greatly reduce the interaction between the operator and HCS imaging system, improving the e±ciency of largescale cell analysis. 7 Over the years, machine learning and deep learning technologies have exhibited remarkable performance in biomedical image classi¯cation. ...

Reference:

Automated apoptosis identification in fluorescence imaging of nucleus based on histogram of oriented gradients of high-frequency wavelet coefficients
Application of a High-Content Screening Assay Utilizing Primary Human Lung Fibroblasts to Identify Antifibrotic Drugs for Rapid Repurposing in COVID-19 Patients

SLAS DISCOVERY Advancing the Science of Drug Discovery

... Programmed cell death, or apoptosis, is a key biological process associated with many types of diseases, including autoimmune and inflammatory diseases and cancer [88]. Since peptidomimetics are known to induce apoptosis [89], HeLa cells were treated with conjugates 1-4, followed by flow cytometry analysis. ...

A fluorogenic cyclic peptide for imaging and quantification of drug-induced apoptosis

Nature Communications

... It is encoded by the PSMD10 gene and plays a crucial role in cell cycle progression, apoptosis and tumorigenesis. Initially, gankyrin was identified in human HCC (12); however, several studies have demonstrated that gankyrin expression is upregulated in other types of cancer (for example kidney, breast, testicular cancer and squamous cell carcinoma) as well (13)(14)(15). ...

The oncogene Gankyrin is expressed in testicular cancer and contributes to cisplatin sensitivity in embryonal carcinoma cells

BMC Cancer

... Furthermore, analysis of published single-cell RNA sequencing (scRNAseq) data revealed that uPAR was significantly upregulated in HSCs in cirrhotic human livers (Fig. S1C). 34 As in humans, uPAR expression was also markedly increased in mouse models of liver fibrosis induced by CCl 4 or a DDC diet compared with expression in the livers of control mice (Fig. S1D-G). Overall, we confirmed that uPAR is a cell surface protein that is overexpressed in liver fibrosis and is a potential target for therapeutic intervention. ...

Resolving the fibrotic niche of human liver cirrhosis at single-cell level

Nature

... MerTK is expressed by many cells including endothelial cells and monocytes/macrophages and is also expressed within the kidney by glomerular cells [20][21][22]. MerTK is a key player in apoptotic cell clearance by phagocytosis; its ligand, the anticoagulant vitamin K-dependent factor protein S, bridges PS exposed on the plasma membrane of apoptotic cells with the MerTK receptor on the surface of phagocytes, enabling phagocytosis to take place [23][24][25]. The absence of a functional MerTK protein leads to a defect in phagocytosis that has been associated with several pathologies such as impaired spermatogenesis, photoreceptor degeneration or autoimmune disease [24,[26][27][28][29]. MerTK expressed by macrophages may also act as a negative regulator of inflammation, as impaired MerTK expression leads to an increase in pro-inflammatory mediators such as interleukin-6 (IL-6), monocyte chemoattractant protein-1 (MCP-1), and tumor necrosis factor-α (TNF-α) [30]. ...

Augmentation of Human Monocyte Responses to Lipopolysaccharide by the Protein S and Mer/Tyro3 Receptor Tyrosine Kinase Axis
  • Citing Article
  • September 2018

The Journal of Immunology

... Neutrophils can be eliminated by macrophages, to return to homeostasis once dangerous molecules are removed [34]. Contemporarily, the apoptotic neutrophils operate to switch the macrophage profile from pro-to anti-inflammatory (M1 to M2), suppressing inflammatory cytokines such as TNF and IL8 [51]. ...

Neutrophils induce macrophage anti-inflammatory reprogramming by suppressing NF-κB activation

Cell Death and Disease

... In mammalian cells, this represents a truly bewildering array of phagocytic receptors with overlapping activities (reviewed in Refs. [142,143]). This redundancy has rendered the investigation of mammalian efferocytic receptors problematic. ...

The “Phagocytic Synapse” and Clearance of Apoptotic Cells
Frontiers in Immunology

... In monocytes, GSK3β inactivation reduced corticosteroid suppression of proinflammatory responses by inhibition of the enzymatic activity of HDAC2. 39 Glycyrrhizic acid inhibited inflammatory factors by mediation of the PI3K/Akt/GSK3β pathway. 40 Thus, GSK3β may provide a link between the PI3K/Akt pathway and HDAC2. ...

Glycogen synthase kinase-3β modulation of glucocorticoid responsiveness in COPD

AJP Lung Cellular and Molecular Physiology

... MAPK pathways are involved in the activation of transcription factors such as NF-κB and AP-1, and the activation of p38 MAPK pathway could lead to glucocorticoid insensitivity for SA patients. [67][68][69] Furthermore, p38 MAPK is crucial in the allergic inflammatory cascade because it is needed in the upregulation of adhesion molecules on eosinophils and epithelial cells when allergy happens. 70 Another in-vitro experiment proves that the inhibition of p38 MAPK pathway may lead to additive and synergistic anti-inflammatory effects and reverse the glucocorticoid insensitivity when corticosteroids are used together. ...

Oxidants Induce a Corticosteroid-Insensitive Phosphorylation of Histone 3 at Serine 10 in Monocytes

... A large dose of corticosteroids such as a 14-day course of oral prednisolone or an intramuscular dose of triamcinolone is often administered for the treatment of uncontrolled asthma including that of exacerbations (1). Triamcinolone injections are sometimes used for patients with uncontrolled asthma who are not adherent to maintenance treatment with either inhaled and/ or oral corticosteroid therapy. ...

Corticosteroids: use and insensitivity in severe asthma
  • Citing Article
  • March 2011

European Respiratory Monograph