Biology subjects

Plate, M.

Publications and source records attributed to Plate, M..

9 recordsLinked to original sources

bioRxiv2026

Multi-omics reveals a monocyte-macrophage-fibroblast axis in post-COVID-19 fibroinflammatory lung remodelling

Post-COVID-19 residual lung abnormalities (RLA) are associated with persistent respiratory symptoms and radiological changes, yet the underlying mechanisms remain unclear. We performed integrated multi-omic profiling of paired bronchoalveolar lavage and blood samples from patients with post-COVID-19 RLA and healthy controls, combining single-cell RNA sequencing, CITE-seq, single-cell T cell receptor sequencing, bronchoalveolar lavage fluid proteomics and functional fibroblast assays. In post-COVID-19 RLA lungs, we identified an increased abundance of profibrotic SPP1hi monocyte-derived alveolar macrophages, arising from an expanded circulating HLA-DRlowCD163+PDE4Dhi classical monocyte progenitor population, supporting a blood-lung myeloid axis. Cell-cell communication modelling positioned macrophages as central hubs of immune-stromal crosstalk, promoting monocyte recruitment with profibrotic priming, and fibroblast activation. Proteomic analysis of bronchoalveolar lavage fluid from post-COVID-19 RLA and idiopathic pulmonary fibrosis, compared with healthy controls, revealed shared and distinct signatures. These alveolar proteins in post-COVID-19 RLA were predominantly attributed to myeloid cells and predicted to engage fibroblast receptors. Bronchoalveolar lavage fluid induced fibroblast proliferation, differentiation and collagen deposition in vitro, with proliferation attenuated by the antifibrotic drug nintedanib. We also identified compartment-specific lymphoid dysregulation, including depletion of mucosal-associated invariant T (MAIT) cells in both the lung and blood, decreased natural killer (NK) cells with oligoclonal T cell expansion in the lung, and expansion of regulatory and cytotoxic T cells in the blood. These findings support a persistent monocyte-macrophage-fibroblast axis linking immune dysregulation to fibroproliferative remodelling after COVID-19 and highlights candidate therapeutic targets for post-viral lung fibrosis. We provide a publicly available atlas (on publication).

systems biology↗

bioRxiv2026

Persistence of tobacco-mutated alveolar progenitor cells after smoking cessation mirrors long term risk of lung adenocarcinoma

Tobacco smoke shapes mutations, selection and clonal expansion in lung epithelial cells. Smoking cessation leads to divergent epidemiology in the two most common lung cancers: squamous cell carcinoma risk declines sharply, while adenocarcinoma risk is preserved. To investigate this discrepancy, we analysed 806 genomes of alveolar type II (AT2) cells and found persistently elevated mutation burdens after cessation. In contrast, in the proximal airway, rare basal stem cells with near-normal mutation burden expand after cessation, protecting against squamous cell carcinoma. Targeted single-molecule DNA sequencing of AT2 cells revealed positive selection for TP53 and cell cycle and MAPK genes, supporting continued cancer risk. A multistage carcinogenesis model emphasised the importance of a small population of hypermutated cells in the alveoli and reproduced the divergent epidemiological trajectories following cessation due to distinct regenerative dynamics. Our findings suggest that differences in mutational burden and clonal regeneration explain post-cessation trends in lung cancer subtypes. One sentence summaryCancer risk reflects not only cumulative exposure to toxins, but the capacity of tissues to erase genomic damage through regeneration from protected cells with clonal advantage.

genomics↗

bioRxiv2024

Critical role for the TGF-β1/mTORC1 signalling axis in defining the transcriptional identity of CTHRC1+ pathologic fibroblasts

Fibrosis, defined as the abnormal deposition of extracellular matrix (ECM), represents the concluding pathological outcome in a number of inflammatory, immune-mediated and metabolic diseases. Recent single cell RNA-sequencing studies have highlighted the diversity and functional heterogeneity of fibroblast populations in multiple fibrotic conditions. These include a novel pathogenic population of high collagen-producing fibroblasts, characterised by expression of the secreted glycoprotein, collagen triple helix repeat containing 1 (CTHRC1). The cardinal pro-fibrotic mediator TGF-{beta}1 has been widely implicated in promoting fibrogenesis and is a potent inducer of CTHRC1 and COL1A1 expression. In addition to the canonical Smad signalling pathway, TGF-{beta}1-induced collagen I production is under critical regulatory control by the mTORC1/4E-BP1 signalling hub. Using pharmacological inhibition in combination with gene-editing approaches, we now demonstrate that the role of the mTORC1 axis extends to the regulation of over a third of all TGF-{beta}1 regulated matrisome genes. We provide further evidence that the global transcriptome of TGF-{beta}1-stimulated fibroblasts in vitro matches that of a subpopulation of the high collagen expressing CTHRC1+ pathological fibroblast population in the IPF lung. In contrast, the TGF-{beta}1 induced transcriptome of fibroblasts in which mTORC1 signalling is disrupted (by RPTOR gene editing using CRISPR-Cas9) does not map to any fibroblast population present in human control or fibrotic lung. Using the novel and selective mTORC1 inhibitor RMC-5552, we further demonstrate a direct functional link between mTORC1 signalling and the acquisition of key marker genes which define the CTHRC1+ fibroblast population in IPF. These data demonstrate, for the first time, a critical role for the mTORC1 signalling hub in determining the transcriptional identity of the CTHRC1+ pathological fibroblast population and provide strong scientific support for targeting mTORC1 as a therapeutic strategy in IPF and potentially other fibrotic conditions associated with dysregulated TGF-{beta}1 signalling in the fibrotic niche.

cell biology↗

bioRxiv2024

mTOR dysregulation induces IL6 and paracrine AT2 cell senescence impeding lung repair in lymphangioleiomyomatosis

Lymphangioleiomyomatosis (LAM) is a rare disease which causes lung cysts and respiratory failure. TSC2 deficient LAM cells with dysregulated mTOR signalling form nodules with fibroblasts causing lung injury. We examined if mTOR dysregulation could induce senescence and impair responses to lung injury. Senescence markers p21 and p16 were increased in LAM lungs and co-localised with alveolar type 2 cells. The SenMayo senescence gene panel was upregulated in LAM alveolar type 2 cells with senescence supressed by mTOR inhibition in patients. LAM cell / fibroblast spheroid cultures induced senescence markers in alveolar type 2 cell organoids, altered their growth and delayed epithelial scratch wound repair. Upstream regulator analysis predicted alveolar type 2 cell IL6 receptor activation. IL6 was produced by LAM cells, induced p16 and p21 in alveolar type 2 cells, inhibited epithelial wound resolution and was overexpressed in LAM patient serum where it was related to lung function. Wound repair in the presence of TSC2 null LAM cell / fibroblast spheroids was enhanced by the IL6 receptor antagonist Tocilizumab. Our findings show TSC2 loss induces senescence and IL6 production which are associated with impaired lung repair. Targeting IL6 signalling in parallel with mTOR inhibition, may reduce lung damage in LAM.

cell biology↗

bioRxiv2024

Prenatal VEGF Nano-Delivery Reverses Congenital Diaphragmatic Hernia-Associated Pulmonary Abnormalities

RationaleCongenital diaphragmatic hernia (CDH) results in lung hypoplasia. In severe cases, tracheal occlusion (TO) can be offered to promote lung growth. However the benefit is limited, and novel treatments are required to supplement TO. Vascular endothelial growth factor (VEGF) is downregulated in animal models of CDH and could be a therapeutic target, but its role in human CDH is not known. ObjectivesTo investigate whether VEGF supplementation could be a suitable treatment for CDH-associated lung pathology. MethodsFetal lungs from CDH patients were used to determine pulmonary morphology and VEGF expression. A novel human ex vivo model of fetal lung compression recapitulating CDH features was developed and used to determine the effect of exogenous VEGF supplementation (Figure 1A). A nanoparticle-based approach for intra-pulmonary delivery of VEGF was developed by conjugating it on functionalized nanodiamonds (ND-VEGF) and was tested in experimental CDH in vivo. O_FIG O_LINKSMALLFIG WIDTH=138 HEIGHT=200 SRC="FIGDIR/small/581170v1_fig1.gif" ALT="Figure 1"> View larger version (77K): org.highwire.dtl.DTLVardef@2ba882org.highwire.dtl.DTLVardef@4413d2org.highwire.dtl.DTLVardef@17155aborg.highwire.dtl.DTLVardef@1af7c73_HPS_FORMAT_FIGEXP M_FIG O_FLOATNOFigure 1C_FLOATNO (A) Schematic of the study design based on the analysis of the early-stage CDH fetal lung sections to assess early hypoplasia and VEGF impairment. In parallel, a human compression-based CDH model will be developed to validate the CDH phenotype and test a therapeutical approach to rescue lung hypoplasia. (B) H&E analysis of 18 and 22 pcw post-mortem CDH human lung tissue reveals impaired epithelial development compared to control healthy tissue at matching developmental stages. Scale bar 100m. (C) Morphometric analysis of CDH and healthy lung tissue at 18-22 pcw reveals decreased values of volume densities of air space (Vair%) and corresponding higher values of volume densities of alveolar septa (Vsep%) in CDH tissues compared to healthy tissue at the same developmental stages. A similar trend can be observed for the mean linear intercept of air space (Lma%) and its corresponding mean linear intercept of septal thickness (Lmw%). (D) Histologic analysis of VEGFA, KDR, Ki67 and NKX2-1 markers in normal and CDH fetal lung tissue at 18 and 22 pcw. Scale bar 100m. (E) Quantification of epithelial VEGFA and KDR expression reported in D shows a significant decrease for both markers in CDH compared to healthy samples. Correspondingly, the percentage of Ki67-positive epithelial cells is significantly lower in CDH compared to healthy samples, with no significant differences in the number of NKX2-1-positive cells. ***<p=0.001. (F) Immunofluorescence analysis of ECAD in normal and CDH fetal lung tissue at 18 and 22 pcw. Scale bar 100m. (G) Quantification of epithelial nuclear density based on results in Figure F shows no significant differences between CDH and healthy tissue. C_FIG Measurements and Main ResultsVEGF expression was downregulated in distal pulmonary epithelium of human CDH fetuses in conjunction with attenuated cell proliferation. The compression model resulted in impaired branching morphogenesis similar to CDH and downregulation of VEGF expression in conjunction with reduced proliferation of terminal bud epithelial progenitors; these could be reversed by exogenous supplementation of VEGF. Prenatal delivery of VEGF with the ND-VEGF platform in CDH fetal rats resulted in lung growth and pulmonary arterial remodelling that was complementary to that achieved by TO alone with appearances comparable to healthy controls. ConclusionsThis innovative approach could have a significant impact on the treatment of CDH.

bioengineering↗

bioRxiv2024

Pyruvate metabolism dictates fibroblast sensitivity to GLS1 inhibition during fibrogenesis

Fibrosis is a chronic disease characterized by excessive extracellular matrix (ECM) production which leads to destruction of normal tissue architecture and disruption of organ function. Fibroblasts are key effector cells of this process and respond to a host of pro-fibrotic stimuli, including notably the pleiotropic cytokine, TGF-{beta}1, which promotes fibroblast to myofibroblast differentiation. This is accompanied by the simultaneous rewiring of metabolic networks to meet the biosynthetic and bioenergetic needs of contractile and ECM-synthesizing cells, but the exact mechanisms involved remain poorly understood. In this study, we report that extracellular nutrient availability profoundly influences the TGF-{beta}1 transcriptome of primary human lung fibroblasts (pHLFs) and the "biosynthesis of amino acids" emerges as a top enriched transcriptional module influenced by TGF-{beta}1. We subsequently uncover a key role for pyruvate in influencing the pharmacological impact of glutaminase (GLS1) inhibition during TGF-{beta}1-induced fibrogenesis. In pyruvate replete conditions which mimic the physiological concentration of pyruvate in human blood, GLS1 inhibition is ineffective in blocking TGF-{beta}1-induced fibrogenesis, as pyruvate is able to be used as the substrate for glutamate and alanine production via glutamate dehydrogenase (GDH) and glutamic-pyruvic transaminase 2 (GPT2), respectively. We further show that dual targeting of either GPT2 or GDH in combination with GLS1-inhibition is required to fully block TGF-{beta}1-induced collagen synthesis. These findings embolden a therapeutic strategy aimed at additional targeting of mitochondrial pyruvate metabolism in the presence of a glutaminolysis inhibitor in order to interfere with the pathological deposition of collagen in the setting of pulmonary fibrosis and potentially other fibrotic conditions.

cell biology↗

bioRxiv2022

The RNA binding proteins ZFP36L1 and ZFP36L2 modulate transcriptional and post-transcriptional genome-wide effects of glucocorticoids

Glucocorticoids (GCs) are one of the most used anti-inflammatory drugs worldwide. Despite their widespread use, our understanding of their post-transcriptional effects remains poorly understood. The tristetraprolin (TTP) RNA binding protein (RBP) family (ZFP36, ZFP36L1 and ZFP36L2) has been implicated in inflammation regulation via binding to AU-rich elements (ARE) in mRNAs, with TTP being implicated in GC modulation. We hypothesised that ZFP36L1 and ZFP36L2 are part of the GC pathway and tested this hypothesis in bronchial epithelium, which commonly encounters GC in vivo upon inhalation. Our data show that dexamethasone, a commonly used GC, modulated the levels, subcellular localisation and RNA binding of ZFP36L1/L2. Employing Frac-seq (subcellular fractionation and RNA-sequencing), we show that GC modulated distinct subsets of RNAs in a subcellular-dependent manner. In addition to their mostly known transcriptional effects (116 differentially expressed genes, DEGs), GCs modified the binding to monosomes of myriad mRNAs (83 differentially bound genes, DBGs). We also demonstrate that ZFP36L1/L2 modulated gene expression mainly at the total cytoplasmic and polyribosome binding levels. ZFP36L1/L2 down-regulation led to an increase in ARE-containing mRNAs and a pronounced modification of the effects of GC on gene expression. We observed a small overlap of genes modulated by GCs when comparing control and ZFP36L1/L2 knockdown cells, in a subcellular-dependent manner Our data also suggest a novel role for these RBPs and GCs in epithelial biology via regulation of mRNAs encoding proteins important for epithelial cell function including cellular structure. We believe that our data has further implications in how we investigate gene expression. We show the power of employing sub-cellular fractionation when analysing genome-wide effects for known transcriptional modulators such as GCs, as well as a tool to demonstrate the extent of the effect of RBPs on gene expression modulation beyond total RNA levels.

molecular biology↗

bioRxiv2020

Transcriptome analysis of IPF fibroblastic foci identifies key pathways involved in fibrogenesis

Fibroblastic foci (FF) represent the cardinal pathogenic lesion in idiopathic pulmonary fibrosis (IPF) and comprise activated fibroblasts and myofibroblasts, the key effector cells responsible for dysregulated extracellular matrix deposition in multiple fibrotic conditions. The aim of this study was to define the major transcriptional programmes involved in fibrogenesis in IPF by profiling un-manipulated myo/fibroblasts within FF in situ by laser capture microdissection. The challenges associated with deriving gene calls from low amounts of RNA and the absence of a meaningful comparator cell type were overcome by adopting novel data mining strategies and by using weighted gene co-expression network analysis (WGCNA), as well as an eigengene-based approach to identify transcriptional signatures which correlate with fibrillar collagen gene expression. WGCNA identified prominent clusters of genes associated with cell cycle, inflammation/differentiation, translation and cytoskeleton/cell adhesion. Collagen eigengene analysis revealed that TGF-{beta}1, RhoA kinase and the TSC2/RHEB axis formed major signalling clusters associated with collagen gene expression. Functional studies using CRISPR-Cas9 gene edited cells demonstrated a key role for the TSC2/RHEB axis in regulating TGF-{beta}1-induced mTORC1 activation and collagen I deposition in mesenchymal cells reflecting IPF and other disease settings, including cancer-associated fibroblasts. These data provide strong support for the human tissue-based and bioinformatics approaches adopted to identify critical transcriptional nodes associated with the key pathogenic cell responsible for fibrogenesis in situ and further identifies the TSC2/RHEB axis as a potential novel target for interfering with excessive matrix deposition in IPF and other fibrotic conditions. What is the key question?Can we identify a transcriptional signature associated with collagen gene expression in the fibrotic focus, the cardinal fibrotic lesion in IPF? What is the bottom line?We herein define the major transcriptional programmes involved in fibrogenesis in IPF by profiling myo/fibroblasts within FF in situ by laser capture microdissection. Why read on?The data provide strong support for a human tissue-based approach to identify critical transcriptional nodes associated with fibrogenesis in situ and further identifies the TSC2/RHEB axis as a potential novel target for interfering with excessive matrix deposition in IPF and other fibrotic conditions.

cell biology↗

bioRxiv2017

Genome-wide post-transcriptional dysregulation by microRNAs in human asthma as revealed by Frac-seq

MicroRNAs are small non-coding RNAs that inhibit gene expression post-transcriptionally, implicated in virtually all biological processes. Although the effect of individual microRNAs is generally studied, the genome-wide role of multiple microRNAs is less investigated. We assessed paired genome-wide expression of microRNAs with total (cytoplasmic) and translational (polyribosome-bound) mRNA levels employing Frac-seq in human primary bronchoepithelium from healthy controls and severe asthmatics. Severe asthma is a chronic inflammatory disease of the airways characterized by poor response to therapy. We found genes (=all isoforms of a gene) and mRNA isoforms differentially expressed in asthma, with novel inflammatory and structural mechanisms disclosed solely by polyribosome-bound mRNAs. Gene expression (=all isoforms of a gene) and mRNA expression analysis revealed different molecular candidates and biological pathways, with differentially expressed polyribosome-bound and total mRNAs also showing little overlap. We reveal a hub of six dysregulated microRNAs accounting for [~]90% of all microRNA targeting, displaying preference for polyribosome-bound mRNAs. Transfection of this hub in healthy cells mimicked asthma characteristics. Our work demonstrates extensive post-transcriptional gene dysregulation in asthma, where microRNAs play a central role, illustrating the feasibility and importance of assessing post-transcriptional gene expression when investigating human disease.

systems biology↗