Biology subjects

Athwal, V.

Publications and source records attributed to Athwal, V..

4 recordsLinked to original sources

bioRxiv2026

Mapping vascular plasticity in liver fibrogenesis identifies novel fibrosis-associated endothelial cells in early-stage liver disease

Vascular plasticity is a crucial biological asset enabling our bodies to rapidly adapt to infections and acute inflammation. However, repeated insult during chronic disease can result in these vascular adaptations becoming irreversible, thereby driving disease progression and fibrosis. This study aimed to understand if phenotypic changes in endothelial cell (EC) identity could be indicative of progressive fibrosis and thereby offer new diagnostic and therapeutic opportunities for patients with metabolic dysfunction-associated steatotic liver disease (MASLD). Previous research has documented that a significant shift in EC transcriptomic signature occurs during liver fibrosis in both pre-clinical models and patients. However, the protein expression profile, phenotype and functional role of these new EC subpopulations that are induced during fibrogenesis is unclear. In this study, we integrate high-resolution imaging, proteomic and transcriptomic analysis which collectively highlight a central role for endothelial-to-mesenchymal transition (EndMT)-induced EC plasticity in the derivation of fibrosis-associated EC (FAEC). We demonstrate that: 1) full spectrum flow cytometry can provide new opportunities to categorize and phenotype EC subpopulations, 2) two distinct EndMT-derived FAEC subpopulations expand during fibrogenesis; THY1.2+ICAM1+ and TAGLN+MCAM+ EC that display unique immunomodulatory and metabolic phenotypes, 3) TAGLN+ FAEC are a conserved, pro-fibrotic cell type arising at early stages of MASLD, and 4) increased hepatic expression of TAGLN is significantly associated with detrimental patient outcomes at all stages of liver disease. This study will pave the way for the development of FAEC-specific diagnostic and therapeutic approaches to tackle progressive fibrotic disease. One Sentence SummaryPhenotyping fibrosis-associated endothelial cells reveals pro-fibrotic and immunomodulatory subpopulations at early stages of liver disease. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=112 SRC="FIGDIR/small/710459v2_ufig1.gif" ALT="Figure 1"> View larger version (32K): org.highwire.dtl.DTLVardef@dc91fforg.highwire.dtl.DTLVardef@f526d9org.highwire.dtl.DTLVardef@c9783borg.highwire.dtl.DTLVardef@f469e4_HPS_FORMAT_FIGEXP M_FIG C_FIG

cell biology↗

bioRxiv2023

A spatial map of human liver cirrhosis reveals the patho-architecture and gene signatures associated with cell state transitions during liver disease

Liver fibrosis is a major cause of death worldwide. As a progressive step in chronic liver disease, fibrosis is almost always diagnosed too late with limited treatment options. Here, we uncover the spatial transcriptional landscape driving human liver fibrosis using single nuclei RNA and Assay for Transposase-Accessible Chromatin (ATAC) sequencing to deconvolute multi-cell spatial transcriptomic profiling in human liver cirrhosis. Through multi-modal data integration, we define molecular signatures driving cell state transitions in liver disease and define an impaired cellular response and directional trajectory from hepatocytes to cholangiocytes associated with disease remodelling. We identify pro-fibrogenic signatures in non-parenchymal cell subpopulations co-localised within the fibrotic niche and localise transitional cell states at the scar interface. This combined approach provides a spatial atlas of gene regulation and defines molecular signatures associated liver disease for targeted therapeutics or as early diagnostic markers of progressive liver disease.

genomics↗

bioRxiv2023

PAK1-dependant mechanotransduction enables myofibroblast nuclear adaptation and chromatin organisation during fibrosis

Myofibroblasts are responsible for scarring and organ stiffness during fibrosis. The scar propagates mechanical signals inducing a radical transformation in myofibroblast cell state linked to an increasingly pro-fibrotic phenotype. Here, we have discovered mechanical stress from progressive scarring induces nuclear softening and de-repression of heterochromatin. The parallel loss of H3K9Me3 enables a permissive state for distinct chromatin accessibility and profibrotic gene regulation. By integrating chromatin accessibility profiles (ATAC sequencing) we provide insight into the transcription network and open chromatin landscape underlying the switch in profibrotic myofibroblast states, emphasizing mechanoadaptive pathways linked to PAK1 as key drivers. Through genetic manipulation in liver and lung fibrosis, uncoupling PAK1-dependant signaling impaired the mechanoadaptive response in vitro and dramatically improved fibrosis in vivo. Moreover, we provide human validation for mechanisms underpinning PAK1 mediated mechanotransduction in liver and lung fibrosis. Collectively, these observations provide new insight into the nuclear mechanics driving the profibrotic chromatin landscape in fibrosis, highlighting actomyosin-dependent mechanisms linked to chromatin organisation as urgently needed therapeutic targets in fibrosis.

cell biology↗

bioRxiv2019

SOX9 is required for kidney fibrosis and regulates NAV3 to control renal myofibroblast function in mice and humans

Renal fibrosis is a common endpoint for many chronic kidney diseases. Extracellular matrix (ECM) from myofibroblasts causes progressive scarring and organ failure. The mechanisms underlying fibrogenesis and how it is sustained are incompletely understood. Here, we show that the transcription factor, Sex determining region Y-box 9 (SOX9), is required for kidney fibrosis. From genome-wide analysis we identify Neuron navigator 3 (NAV3) downstream of SOX9. NAV3 was upregulated in kidney disease in patients and following renal injury in mice colocalised with SOX9. By establishing an in vitro model of renal pericyte transition to myofibroblast we demonstrated that NAV3 is required for multiple aspects of fibrogenesis including actin polymerization linked to cell migration and sustaining SOX9 and active YAP1 levels. In summary, our work discovers novel SOX9-NAV3-YAP1/SOX9 circuitry as a new mechanism to explain the progression of kidney fibrosis and points to NAV3 as a novel target for pharmacological intervention.

cell biology↗