Biology subjects

Carr, L.

Publications and source records attributed to Carr, L..

5 recordsLinked to original sources

bioRxiv2026

Loss of PKN2 drives fibroblast reprogramming and extracellular matrix remodelling in pulmonary fibrosis

Introduction Idiopathic pulmonary fibrosis (IPF) is a progressive fibrotic lung disease characterised by aberrant fibroblast function, extracellular matrix (ECM) remodelling and defective tissue repair. Protein kinase N2 (PKN2) is associated with accelerated forced vital capacity decline in IPF, but its functional role in pulmonary fibrosis remains unknown. We hypothesised that PKN2 regulates fibroblast phenotype and tissue repair. Methods PKN2 expression was assessed in human lung tissue, induced sputum and primary airway and parenchymal fibroblasts from non-fibrotic controls and patients with interstitial lung disease (ILD). DNA methylation was profiled using the Illumina HumanMethylationEPIC array. PKN2 function was investigated by siRNA-mediated depletion in primary human lung fibroblasts using transcriptomic, proteomic and functional analyses. Tissue repair was assessed following pharmacological PKN inhibition in zebrafish. Results PKN2 expression was reduced in ILD lung tissue and primary airway and parenchymal fibroblasts and further suppressed by TGF-{beta}1. Differential methylation was identified across the PKN2 locus in both fibroblast populations. Integrated transcriptomic and proteomic profiling following PKN2 depletion revealed coordinated remodelling of ECM, cell adhesion, non-canonical WNT and VEGF pathways, including dysregulation of COL1A1, WNT, VEGF and MMP1. PKN2 loss increased VEGF and MMP-1 secretion and accelerated fibroblast wound closure. PKN inhibition altered epithelial organisation and collagen fibre alignment during zebrafish wound repair. Conclusion PKN2 loss drives fibroblast reprogramming and aberrant ECM remodelling, establishing PKN2 as an important regulator of pulmonary fibroblast homeostasis and tissue repair.

cell biology↗

bioRxiv2024

Dynamic Wt1 expression in the gastrulation-stage mouse embryo specifies vascular and visceral smooth muscle cell fate independently from mesothelial fate.

1.The Wilms Tumour protein (WT1) was previously linked to the mesothelial and vascular smooth muscle cell (vSMC) lineage in the mouse intestine, with evidence suggesting that intestinal vSMCs arise from the mesothelium. Here, we report that WT1 is already expressed, unexpectedly, during gastrulation, in cells that specify a population of SMC precursor cells in the lateral plate mesoderm (LPM). Tamoxifen-induced genetic lineage tracing of Wt1-expressing cells revealed that vSMC and visceral smooth muscle cells (visSMCs) of the foetal mid-gut, but not mesothelial cells, were labelled after Tamoxifen administration at E7.5 or E8.5. Analysis of single cell RNA sequencing (scRNAseq) datasets of gastrulation-stage mouse embryos and confocal microscopy demonstrated Wt1 expression in epiblast, primitive streak, emerging mesoderm and, from E7.5 onwards, in the LPM. Co-expression of signature smooth muscle markers in Wt1-expressing cells in gastrulation-stage embryos revealed that vSMC and visSMC fate is specified independently from visceral mesothelium formation. Furthermore, Tamoxifen-induced Wt1 knock-out at E7.5 affected vascularisation in the E12.5 intestine. Taken together, our study provides novel insight into the developmental lineage of smooth muscle specified by WT1 expression during gastrulation. Summary StatementThis study provides novel insight into the developmental lineage of smooth muscle cells in the intestine and mesentery, specified by WT1 expression during gastrulation.

developmental biology↗

bioRxiv2023

A palmitoyl transferase chemical genetic system to map ZDHHC-specific S-acylation

The 23 human ZDHHC S-acyltransferases catalyze long-chain S-acylation at cysteine residues across an extensive network of hundreds of proteins important for normal physiology or dysregulated in disease. Here we present a technology platform to directly map the protein substrates of a specific ZDHHC for the first time at the whole proteome level, in intact cells. Structure-guided engineering of paired ZDHHC hole mutants and bumped chemically tagged fatty acid probes enabled probe transfer to specific protein substrates with excellent selectivity over wild type ZDHHCs. Chemical genetic systems were exemplified for five ZDHHCs (3, 7, 11, 15 and 20), and applied to generate the first de novo ZDHHC substrate profiles, identifying >300 unique and shared substrates across multiple cell lines and S-acylation sites for novel functionally diverse substrates. We expect that this powerful and versatile platform will open a new window on S-acylation biology for a wide range of models and organisms.

molecular biology↗

bioRxiv2021

Fyn kinase inhibition using AZD0530 improves recognition memory and reduces depressive-like behaviour in an experimental model of Parkinson's disease

Fyn kinase has recently been established as a major upstream regulator of neuroinflammation in PD. This study aimed to determine if inhibition of Fyn kinase could lead to reduced neuroinflammation and improvements in motor and non-motor impairments in an early-stage model of PD. An experimental model of PD was produced using intra-striatal injection (4{micro}l) of the neurotoxin 6-OHDA (5{micro}g/{micro}l). Sprague Dawley rats (n=42) were given either vehicle, 6mg/kg or 12mg/kg of Fyn kinase inhibitor (AZD0530) daily for 32 days via oral gavage and tested on a battery of tasks assessing motor, cognitive and neuropsychiatric outcomes. AZD 0530 administration led to improvement in volitional locomotion and recognition memory, as well as a reduction in depressive-like behaviour. Pathologically, an inflammatory response was observed; however, there were no significant differences in markers of neuroinflammation between treatment groups. Taken together, results indicate a potential therapeutic benefit for use of Fyn kinase inhibition to treat non-motor symptoms of PD, although mechanisms remain to be elucidated. HIGHLIGHTSO_LIFyn kinase has recently been proposed as a major upstream regulator of microglial activation in Parkinsons disease (PD). C_LIO_LIThis study was the first to evaluate the effects of Fyn kinase inhibition in a rodent model of PD. C_LIO_LIFyn kinase inhibition using the Fyn kinase inhibitor AZD 0530 was capable of improving volitional locomotion and recognition memory and reducing depressive-like behaviour in a rodent model of PD. C_LIO_LIInterestingly, while increases in microglial activation were observed in this rodent model of PD, AZD 0530 did not significantly reduce this activation. C_LIO_LIThis suggests that the behavioural improvements associated with Fyn kinase inhibition may occur independently of neuroinflammation and may be attributable to other brain mechanisms, including actions on NMDA or 5-HT6 receptors. C_LI

neuroscience↗

bioRxiv2020

Wt1-expressing cells contribute to mesoderm-derived tissues in intestine and mesentery in two distinct phases during murine embryonic development.

Previously, genetic lineage tracing based on the mesothelial marker Wt1, appeared to show that peritoneal mesothelial cells have a range of differentiative capacities and are the direct progenitors of vascular smooth muscle in the intestine. However, it was not clear whether this was a temporally limited process or continued throughout postnatal life. Here, using a conditional Wt1-based genetic lineage tracing approach, we demonstrate that the postnatal and adult peritoneum covering intestine, mesentery and body wall only maintained itself and failed to contribute to other visceral tissues. Pulse-chase experiments of up to 6 months revealed that Wt1-expressing cells remained confined to the peritoneum and failed to differentiate into cellular components of blood vessels or other tissues underlying the peritoneum. Ablation of Wt1 in adult mice did not result in changes to the intestinal wall architecture. In the heart, we observed that Wt1-expressing cells maintained the epicardium and contributed to coronary vessels in newborn and adult mice. Our results demonstrate that Wt1-expressing cells in the peritoneum have limited differentiation capacities, and that contribution of Wt1-expressing cells to cardiac vasculature is based on organ-specific mechanisms.

developmental biology↗