Biology subjects

Johnson, S. R.

Publications and source records attributed to Johnson, S. R..

18 recordsLinked to original sources

bioRxiv2026

Ethyl-iophenoxic acid as a serum biomarker for marsupial species in oral bait trials

Ethyl-iophenoxic acid (Et-IPA) is widely recognized as a useful biomarker to confirm oral bait consumption in eutherian species. In historical studies on marsupials, Et-IPA was rapidly eliminated from brushtail possums (Trichosurus vulpecula) and swamp wallabies (Wallabia bicolor) suggesting limited use for marsupial species. However, a 1 mg oral dose of Et-IPA was detectable in the marsupial Tasmanian devils (Sarcophilus harrisii) for [≥] 56 days suggesting the biomarker can be used in a devil bait vaccine program. To assess Et-IPA marking in off-target marsupials that may consume baits, we administered 1 mg oral doses of Et-IPA to brushtail possums, forester kangaroos (Macropus giganteus tasmaniensis), spotted-tailed quolls (Dasyurus maculatus) and eastern quolls (Dasyurus viverrinus). Liquid chromatography with tandem mass spectrometry was used to detect and quantify serum Et-IPA. Et-IPA was detected in the serum on day 2 but was not detected by day 14 in any of the species tested, including the two quoll species which are in the same carnivorous Dasyuridae family as the devils. The rapid elimination of Et-IPA in the marsupials included in this study suggests it is not useful as a biomarker for these species. Furthermore, rapid elimination in the kangaroos and possums suggests that Et-IPA is unlikely to accumulate in the food chain following distribution of Et-IPA-marked oral bait vaccines for Tasmanian devils. Short summary for non-expertsA recent study in Tasmanian devils (Sarcophilus harrisii) challenged the concept that ethyl iophenoxic acid (Et-IPA) is not a useful serum biomarker for marsupials. Using the same sensitive liquid chromatography-tandem mass spectrometry method we detected serum Et-IPA in four marsupial species on day two post-ingestion but by day 14, serum Et-IPA was undetectable. These findings indicate that Et-IPA is an unsuitable biomarker for these species and suggest that Et-IPA from devil bait vaccines is unlikely to bioaccumulate in the Tasmanian environment.

zoology↗

bioRxiv2026

Semirandom DNA adducts regulate a filamentous defence-associated reverse transcriptase

Retrons and several defence-associated reverse transcriptases (DRTs) synthesize non-genomic DNA for bacteriophage immunity. In some instances, this non-genomic DNA is of undefined, semirandom sequence. How undefined DNA sequences impart antiphage defence is not known. Here we report the cryo-EM structure and functional characterization of the DRT1 antiphage defence system. We show that DRT1 performs template-free, protein-primed DNA synthesis to generate semirandom DNA adducts. DNA synthesis activates the nitrilase domain of DRT1 while DNA adducts drive assembly of quiescent DRT1 filaments. Filamentous DRT1 is comprised of domain-swapped C-termini that are entwined, forming pseudoknots between tetrameric stacks. This configuration occludes the apo-nitrilase active site, resulting in a dormant state. Bacteriophage escape mutants identify a T4 single-stranded DNA helicase required for DRT1 activity. Functionally, DRT1 resembles a minimal retron where a single gene produces an RT, effector, and non-genomic antitoxin DNA.

microbiology↗

bioRxiv2024

Multiscale single-cell assessment of the fibrotic niche in idiopathic pulmonary fibrosis

BackgroundIdiopathic pulmonary fibrosis (IPF) is a progressive, fatal disease characterised by excessive extracellular matrix deposition within the lung. Recent advances in single-cell RNA sequencing have identified distinct fibrotic populations, yet their origins and spatial relationships remain incompletely understood. MethodsUsing spatial transcriptomics and Hyperion imaging mass cytometry we compared the cellular composition in formalin fixed paraffin embedded fibrotic lesions (n=9 patients) with control lung (n=9), and cellular interactions were inferred using CellChat V2 ligand-receptor analysis. Monolayers of airway epithelial cells were used to identify changes in keratin (KRT) expression following cell detachment and cyclical mechanical stretch. ResultsSpatial multiomics profiling of human lung cells confirmed the in situ localisation of previously described IPF-enriched populations, and identified a previously unrecognized KRT5low/KRT17 epithelial population derived from airway basal cells that progressively acquiring molecular features of aberrant basaloid cells, forming a unique fibrotic niche enriched with the Secreted Phosphoprotein 1 (SPP1) positive macrophages. Functional studies demonstrated that epithelial detachment and cyclical mechanical stretch drive KRT5 reduction, providing a mechanism for the emergence of this transitional state. In addition, we also identified distinct immune-stromal niches enriched in lymphocytes and alveolar fibroblasts. ConclusionThese findings delineate distinct fibrotic epithelial niches in IPF and support a model in which epithelial loss induces aberrant basaloid differentiation and fibroblast activation, with subsequent airway traction and epithelial detachment generating a secondary niche enriched in basal-derived KRT5low/KRT17 cells and SPP1 macrophages.

molecular biology↗

bioRxiv2024

Genetic burden of dysregulated cytoskeletal organisation in the pathogenesis of pulmonary fibrosis

BackgroundRare genetic variants contribute to pulmonary fibrosis (PF) risk and outcome, with known variants highlighting the importance of impaired telomere maintenance and surfactant biology. However, much of the disrupted genetic architecture of PF remains unexplained. This study aimed to identify genes with rare pathogenic coding variants that represented a burden at the exon level associated with the pathogenesis of PF. MethodsPF case cohorts included the PROFILE study of incident idiopathic pulmonary fibrosis (IPF) and PF-classified participants from the Genomics England 100K (GE100KGP) study. Whole genome sequencing data were used to test the burden of rare protein altering variants (PAVs; CADD score >20) defined by minor allele frequency <0.1% in the summary level gnomAD reference database (v3.1.2). A summary exon-level pathogenicity score was derived by standardising PAV predictions from functional annotation tools (AlphaMissense, REVEL, ClinPred, CADD, PolyPhen-2, SIFT) averaged across exons. SKAT-O based kernel regression associated exon-level pathogenicity features with disease progression and survival. Single cell lung transcriptomic datasets were harmonised to evaluate expression patterns and gene ontology characterised enriched molecular functions. ResultsAcross 507 PROFILE cases and 451 GE100KGP cases, each compared against 76,156 reference participants, 77 genes showed overlapping significant rare PAV burden, comprising 206 concordant PAVs. Of these, 15 genes had exons with pathogenicity scores that were associated with worse clinical outcomes in IPF, including FAT4 exon-10 and DNAH7 exon-43. Dysregulated gene expression of COL6A3 and FAT4 was observed in IPF lung fibroblasts, while DNAH7, DNAH12 and PCM1 showed high expression in IPF epithelial cells. The top enriched molecular functions were related to cytoskeletal motor activity. ConclusionsRare PAV burden highlighted that pathogenicity within specific exons was associated with PF risk and worse clinical outcomes, identifying genes with dysregulated expression in disease lung cells. The genetic architecture implicates disrupted cytoskeletal organisation in the pathogenesis of PF.

genetics↗

bioRxiv2024

Association between mosaic loss of chromosome Y and pulmonary fibrosis susceptibility and severity

Background Pulmonary fibrosis (PF) is a rare lung disease with diverse pathogenesis and multiple interconnected underlying biological mechanisms. Mosaic loss of chromosome Y (mLOY) is one of the most common forms of acquired chromosome abnormality in men, which has been reported to be associated with increased risk of various chronic progressive diseases including fibrotic diseases. However, the exact role of mLOY in the development of PF remains elusive and to be elucidated. MethodsWe adopted three complementary approaches to explore the role of mLOY in the pathogenesis of PF. We used copy number on chromosome Y to estimate mLOY comparing patients in PROFILE and gnomAD cohorts and between cases and control patients from the GE100KGP cohort. Correlation of mLOY with demographic and clinical variables was tested using patients from PROFILE cohort. Lung single-cell transcriptomic data were analysed to assess the cell types implicated in mLOY. We performed Mendelian randomisation to examine the causal relationship between mLOY, IPF, and telomere length. ResultsThe genetic analysis suggests that mLOY is found in PF from both case cohorts but when compared with an age matched population the effect is minimal (P = 0.0032). mLOY is related to age (P = 0.00021) and shorter telomere length (P = 0.0081) rather than PF severity or progression. Single-cell analysis indicates that mLOY appears to be found primarily in immune cells and appears to be related to presence and severity of fibrosis. Mendelian randomisation demonstrates that mLOY is not on the causal pathway for IPF, but partial evidence supports that telomere shortening is on the causal pathway for mLOY. ConclusionOur study confirms the existence of mLOY in PF patients and suggests that mLOY is not a major driver of IPF. The combined evidence suggests a triangulation model where telomere shortening leads to both IPF and mLOY.

genomics↗

bioRxiv2024

Extracellular Matrix-Induced Genes May Reduce Response to Rapamycin in LAM

RationaleLymphangioleiomyomatosis (LAM) is a rare cystic lung disease driven by nodules containing TSC2-/- LAM cells and recruited LAM associated fibroblasts (LAFs). Although rapamycin reduces lung function loss, some patients continue to decline meaning additional therapies are needed. ObjectivesTo investigate how the LAM nodule environment affects LAM cell proliferation and the response to rapamycin. MethodsChanges in advanced LAM were identified using shotgun proteomics and immunohistochemistry in tissue from carefully phenotyped patients. Genes potentially associated with rapamycin insensitivity of cells grown on LAF-derived extracellular matrix were identified by RNA sequencing and validated using repurposed pharmacologic inhibitors. Main ResultsMore advanced disease was associated with increasing nodules adjacent to lung cysts and greater decline in forced expiratory volume in 1 sec (FEV1) when treated with rapamycin (p=0.005). In late-stage LAM, proteomics identified upregulation of pathways associated with accumulation of activated fibroblasts, including extracellular matrix deposition, glucose metabolism and the actin cytoskeleton. Picrosirius red staining and immunohistochemistry confirmed deposition of extracellular matrix within LAM nodules. The growth of TSC2-/- model LAM cells was increased on LAF-derived extracellular matrix (LAF ECM), and incompletely supressed by rapamycin (p<0.0001). RNA sequencing of cells grown on LAF ECM identified upregulation of pathways driving cell cycle control, transcription and metabolism in cells. Tractable, pro-proliferative, rapamycin insensitive genes included CDK7, GAS6 and PLAU. Repurposed inhibitors of these pathways inhibited LAM cell proliferation and enhanced the anti-proliferative effect of rapamycin. ConclusionsExtracellular matrix deposited by LAM associated fibroblasts upregulates expression of genes which potentially blunt the response to rapamycin, but offer additional therapeutic opportunities for patients with established LAM.

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

Domainator, a flexible software suite for domain-based annotation and neighborhood analysis, identifies proteins involved in antiviral systems

The availability of large databases of biological sequences presents an opportunity for in-depth exploration of gene diversity and function. Bacterial defense systems are a rich source of diverse, but difficult to annotate genes with biotechnological applications. In this work, we present Domainator, a flexible and modular software suite for domain-based gene neighborhood and protein search, extraction, and clustering. We demonstrate the utility of Domainator through three examples related to bacterial defense systems. First, we cluster CRISPR-associated Rossman fold (CARF) containing proteins with difficult to annotate effector domains, classifying most of them as likely transcriptional regulators and a subset as likely RNAses. Second, we extract and cluster P4-like phage satellite defense hotspots and identify an abundant system related to Lamassu phage defense systems. Third, we integrate a protein language model into Domainator and use it to identify restriction enzymes with low homology to known reference sequences, validating the activity of one example in-vitro. Domainator is made available as an open-source package with detailed documentation and usage examples.

bioinformatics↗

bioRxiv2024

New role of cardiomyocyte Bmal1 in the regulation of sex-specific heart transcriptomes

It has been well established that cardiovascular diseases exhibit significant differences between sexes in both preclinical models and humans. In addition, there is growing recognition that disrupted circadian rhythms can contribute to the onset and progression of cardiovascular diseases. However little is known about sex differences between the cardiac circadian clock and circadian transcriptomes in mice. Here, we show that the the core clock genes are expressed in common in both sexes but the circadian transcriptome of the mouse heart is very sex-specific. Hearts from female mice expressed significantly more rhythmically expressed genes (REGs) than male hearts and the temporal pattern of REGs was distinctly different between sexes. We next used a cardiomyocyte-specific knock out of the core clock gene, Bmal1, to investigate its role in sex-specific gene expression in the heart. All sex differences in the circadian transcriptomes were significantly diminished with cardiomyocyte-specific loss of Bmal1. Surprisingly, loss of cardiomyocyte Bmal1 also resulted in a roughly 8-fold reduction in the number of all the differentially expressed genes between male and female hearts. We conclude that cardiomyocyte-specific Bmal1, and potentially the core clock mechanism, is vital in conferring sex-specific gene expression in the adult mouse heart.

physiology↗

bioRxiv2023

Highly parallelized construction of DNA from low-cost oligonucleotide mixtures using Data-optimized Assembly Design and Golden Gate

Commercially synthesized genes are typically made using variations of homology-based cloning techniques, including polymerase cycling assembly from chemically synthesized microarray-derived oligonucleotides. Here we apply Data-optimized Assembly Design to the synthesis of hundreds of codon-optimized genes in both constitutive and inducible vectors using Golden Gate Assembly. Starting from oligonucleotide pools, we synthesize genes in three simple steps: 1) Amplification of parts belonging to individual assemblies in parallel from a single pool; 2) Golden Gate Assembly of parts for each construct; and 3) Transformation. We construct genes from receiving DNA to sequence confirmed isolates in as little as 4 days. By leveraging the ligation fidelity afforded by T4 DNA ligase, we expect to be able to construct a larger breadth of sequences not currently supported by homology-based methods which require stability of extensive single-stranded DNA overhangs.

synthetic biology↗

bioRxiv2023

Feeding Behavior Modifies Daily Rhythms in Autonomic Signaling and Core Body Temperature to Shape 24-hour Rhythms in Cardiac Electrophysiology

Rhythmic feeding behavior is critical for regulating the phase and amplitude in the {asymp}24-hour variation of the heart rate (RR intervals), ventricular repolarization (QT intervals), and core body temperature in mice. We hypothesized the changes in cardiac electrophysiology associated with feeding behavior were secondary to changes in core body temperature. Telemetry was used to record electrocardiograms and core body temperature in mice during ad libitum-fed conditions and after inverting normal feeding behavior by restricting food access to the light cycle. Light cycle-restricted feeding quickly modified the phase and amplitude of the 24-hour rhythms in RR intervals, QT intervals, and core body temperature to realign with the new feeding time. Heart rate variability analysis and inhibiting {beta}-adrenergic and muscarinic receptors suggested that the changes in the phase and amplitude of the 24-hour rhythms in RR intervals were secondary to changes in autonomic signaling. In contrast, the changes in the QT intervals closely mirrored changes in core body temperature. Studies at thermoneutrality confirmed the daily variation in the QT interval, but not the RR interval, and reflected daily changes in core body temperature (even in ad libitum-fed conditions). Correcting the QT interval for differences in core body temperature helped to unmask QT interval prolongation after starting light cycle-restricted feeding and in a mouse model of long QT syndrome. We conclude feeding behavior alters autonomic signaling and core body temperature to regulate the phase and amplitude in RR and QT intervals, respectively.

physiology↗

bioRxiv2023

Sensitive remote homology search by local alignment of small positional embeddings from protein language models

Accurately detecting distant evolutionary relationships between proteins remains an ongoing challenge in bioinformatics. Search methods based on primary sequence struggle to accurately detect homology between sequences with less than 20% amino acid identity. Profile- and structure-based strategies extend sensitive search capabilities into this twilight zone of sequence similarity but require slow pre-processing steps. Recently, whole-protein and positional embeddings from deep neural networks have shown promise for providing sensitive sequence comparison and annotation at long evolutionary distances. Embeddings are generally faster to compute than profiles and predicted structures but still suffer several drawbacks related to the ability of whole-protein embeddings to discriminate domain-level homology, and the database size and search speed of methods using positional embeddings. In this work, we show that low-dimensionality positional embeddings can be used directly in speed-optimized local search algorithms. As a proof of concept, we use the ESM2 3B model to convert primary sequences directly into the 3Di alphabet or amino acid profiles and use these embeddings as input to the highly optimized Foldseek, HMMER3, and HH-suite search algorithms. Our results suggest that positional embeddings as small as a single byte can provide sufficient information for dramatically improved sensitivity over amino acid sequence searches without sacrificing search speed.

bioinformatics↗

bioRxiv2023

Discovery of novel DNA cytosine deaminase activities enables a nondestructive single-enzyme methylation sequencing method for base resolution high-coverage methylome mapping of cell-free and ultra-low input DNA

Cytosine deaminases have important uses in the detection of epigenetic modifications and in genome editing. However, the range of applications of deaminases is limited by a small number of well characterized enzymes. To expand the toolkit of deaminases, we developed an in-vitro approach that bypasses a major hurdle with their severe toxicity in expression hosts. We systematically assayed the activity of 175 putative cytosine deaminases on an unprecedented variety of substrates with epigenetically relevant base modifications. We found enzymes with high activity on double- and single-stranded DNA in various sequence contexts including novel CpG-specific deaminases, as well as enzymes without sequence preference. We also report, for the first time, enzymes that do not deaminate modified cytosines. The remarkable diversity of cytosine deaminases opens new avenues for biotechnological and medical applications. Using a newly discovered non-specific, modification-sensitive double-stranded DNA deaminase, we developed a nondestructive single-enzyme 5-methylctyosine sequencing (SEM-seq) method. SEM-seq enables accurate, high-coverage, base-resolution methylome mapping of scarce biological material including clinically relevant cell-free DNA (cfDNA) and single-cell equivalent 10 pg input DNA. Using SEM-seq, we generated highly reproducible base-resolution 5mC maps, accounting for nearly 80% of CpG islands for a low input human cfDNA sample offering valuable information for identifying potential biomarkers for detection of early-stage cancer and other diseases. This streamlined protocol will enable robust, high-throughput, high-coverage epigenome profiling of challenging samples in research and clinical settings.

molecular biology↗

bioRxiv2023

Computational Scoring and Experimental Evaluation of Enzymes Generated by Neural Networks

In recent years, generative protein sequence models have been developed to sample novel sequences. However, predicting whether generated proteins will fold and function remains challenging. We evaluate computational metrics to assess the quality of enzyme sequences produced by three contrasting generative models: ancestral sequence reconstruction, a generative adversarial network, and a protein language model. Focusing on two enzyme families, we expressed and purified over 440 natural and generated sequences with 70-90% identity to the most similar natural sequences to benchmark computational metrics for predicting in vitro enzyme activity. Over three rounds of experiments, we developed a computational filter that improved experimental success rates by 44-100%. Surprisingly, neither sequence identity to natural sequences nor AlphaFold2 residue-confidence scores were predictive of enzyme activity. The proposed metrics and models will drive protein engineering research by serving as a benchmark for generative protein sequence models and helping to select active variants to test experimentally.

biochemistry↗

bioRxiv2022

Differential remodelling in small and large murine airways revealed by novel whole lung airway analysis.

Airway remodelling occurs in chronic asthma leading to increased airway smooth muscle (ASM) mass and extra-cellular matrix (ECM) deposition. Whilst extensively studied in murine airways; studies report only selected larger airways at one time point meaning the spatial distribution and resolution of remodelling are poorly understood. Here we use a new method allowing comprehensive assessment of the spatial and temporal changes in ASM, ECM and epithelium in large numbers of murine airways after allergen challenge. Using image processing to analyse 20-50 airways from a whole lung section revealed increases in ASM and ECM after allergen challenge were greater in small and large rather than intermediate airways. ASM predominantly accumulated adjacent to the basement membrane whereas ECM was distributed across the airway wall. Epithelial hyperplasia was most marked in small and intermediate airways. Post challenge, ASM changes resolved over seven days whereas ECM and epithelial changes persisted. The new method suggests large and small airways remodel differently and the long-term consequences of airway inflammation may depend more on ECM and epithelial changes than ASM. The method reduces the number of animals needed, reveals important spatial differences in remodelling and could set new analysis standards for murine asthma models.

physiology↗

bioRxiv2021

A lung targeted miR-29 Mimic as a Therapy for Pulmonary Fibrosis

microRNAs are non-coding RNAs that negatively regulate gene networks. Previously, we reported a systemically delivered miR-29 mimic MRG-201 that reduced fibrosis in animal models, but at doses prohibiting clinical translation. Here, we generated MRG-229, a next-gen miR-29 mimic with improved chemical stability, conjugated with the internalization moiety BiPPB (PDGFbetaR-specific bicyclic peptide). In TGF-b-treated human lung fibroblasts and precision cut lung slices, MRG-229 decreased COL1A1 and ACTA2 gene expression and reduced collagen production. In bleomycin-treated mice, intravenous or subcutaneous delivery of MRG-229 downregulated profibrotic gene programs at doses more than ten-fold lower than the original compound. In rats and non-human primates, and at clinically relevant doses, MRG-229 was well tolerated, with no adverse findings observed. In human peripheral blood decreased mir-29 concentrations were associated with increased mortality in two cohorts potentially identified as a target population for treatment. Collectively, our results provide support for the development of MRG-229 as a potential therapy in humans with IPF. One Sentence SummaryOne Sentence Summary: A stabilized, next-generation miR-29 mimic has been developed that demonstrates efficacy at commercially viable doses with a robust safety margin in non-human primates.

molecular biology↗

bioRxiv2021

Generating novel protein sequences using Gibbs sampling of masked language models

Recently developed language models (LMs) based on deep neural networks have demonstrated the ability to generate fluent natural language text. LMs pre-trained on protein sequences have shown state of the art performance on a variety of downstream tasks. Protein LMs have also been used to generate novel protein sequences. In the present work we use Gibbs sampling of BERT-style LMs, pre-trained on protein sequences using the masked language modeling task, to generate novel protein sequences. We evaluate the quality of the generated sequences by comparing them to natural sequences from the same family. In particular, we focus on proteins from the chorismate mutase type II family, which has been used in previous work as an example target for protein generative models. We find that the Gibbs sampling process on BERT-style models pretrained on millions to billions of protein sequences is able to generate novel sequences that retain key features of related natural sequences. Further, we find that smaller models fine-tuned or trained from scratch on family-specific data are able to equal or surpass the generation quality of large pre-trained models by some metrics. The ability to generate novel natural-like protein sequences could contribute to the development of improved protein therapeutics and protein-catalysts for industrial chemical production.

synthetic biology↗

bioRxiv2020

Lysyl oxidase-like 2 (LOXL2) is Increased in Asthma and Contributes to Asthmatic Airway Remodelling

Airway smooth muscle cells (ASM) are fundamental to asthma pathogenesis, influencing bronchoconstriction, airway hyper-responsiveness, and airway remodelling. Extracellular matrix (ECM) can influence tissue remodelling pathways, however, to date no study has investigated the effect of ASM ECM stiffness and crosslinking on the development of asthmatic airway remodelling. We hypothesised that TGF{beta} activation by ASM is influenced by ECM in asthma and sought to investigate the mechanisms involved. This study combines in vitro and in vivo approaches: human ASM cells were used in vitro to investigate basal TGF{beta} activation and expression of ECM crosslinking enzymes. Human bronchial biopsies from asthmatic and non-asthmatic donors were used to confirm LOXL2 expression ASM. A chronic ovalbumin model of asthma was used to study the effect of LOXL2 inhibition on airway remodelling. We found that ASM cells from asthmatics activated more TGF{beta} basally than non-asthmatic controls and that diseased cell-derived ECM influences levels of TGF{beta} activated. Our data demonstrate that the ECM crosslinking enzyme LOXL2 is increased in asthmatic ASM cells and in bronchial biopsies. Crucially, we show that LOXL2 inhibition reduces ECM stiffness and TGF{beta} activation in vitro, and can reduce subepithelial collagen deposition and ASM thickness, two features of airway remodelling, in an ovalbumin mouse model of asthma. These data are the first to highlight a role for LOXL2 in the development of asthmatic airway remodelling and suggest that LOXL2 inhibition warrants further investigation as a potential therapy to reduce remodelling of the airways in severe asthma.

cell biology↗