Biology subjects

Lee, L. Y.

Publications and source records attributed to Lee, L. Y..

5 recordsLinked to original sources

bioRxiv2025

A Novel FNDC1-NAMPT-NAD axis is Implicated in Small and Large-vessel Arterial Disease and Drives Vascular Calcification

Vascular calcification represents a convergent pathological feature of diverse cardiovascular diseases, yet the upstream molecular programs orchestrating this process remain poorly defined. Here, we uncover fibronectin type III domain-containing 1 (FNDC1) as a previously unrecognized regulator of vascular calcification across both microvascular and macrovascular beds. Integrative transcriptomic profiling of human calciphylaxis lesions and atherosclerotic coronaries identified FNDC1 as one of the most significantly upregulated genes. In primary human vascular smooth muscle cells, FNDC1 drove osteogenic phenotype switch and vascular calcification through activation of PI3K/AKT signaling and metabolic reprogramming. Mechanistically, FNDC1 directly binds to nicotinamide phosphoribosyltransferase (NAMPT) resulting in elevated intracellular NAD levels, thus coupling vascular signaling to control of NAD biosynthesis. In murine models, genetic deletion of Fndc1 or pharmacologic inhibition of NAMPT suppressed arterial calcification and prolonged survival. Clinically, circulating FNDC1 levels were elevated in patients with both calciphylaxis and coronary artery disease and independently predicted cardiovascular risk in 42,687 UK Biobank participants. Together, these findings establish FNDC1 as a central mediator of vascular pathology and highlight the FNDC1- NAMPT-NAD+ axis as a promising target for therapeutic intervention.

cell biology↗

bioRxiv2021

Oligomannosylation and MAN1A1 expression associate strongly with a subset of human cancer types

Aberrant protein glycosylation is a prominent cancer feature. While many tumour-associated glycoepitopes have been reported, advances in glycoanalytics continue to uncover new associations between glycoproteins and cancer. Guided by a comprehensive literature survey suggesting that oligomannosylation (Man5-9GlcNAc2, M5-M9) is a widespread albeit poorly studied glyco-signature in human cancers, we here re-visit a valuable compilation of nearly 500 LC-MS/MS N-glycomics datasets acquired across 11 human cancer types to systematically test for oligomannose-cancer associations. Firstly, our quantitative glycomics data obtained across 34 cancerous cell lines demonstrated that oligomannosylation, particularly the under-processed M7-M9, is a strong pan-cancer feature. We then showed cell surface expression of oligomannosidic epitopes in the promyelocytic leukemic HL-60 cell line using concanavalin A-based flow cytometry. In keeping with literature, our quantitative glycomics data of tumour and matching control tissues and new MALDI-MS imaging data of tissue microarrays showed a strong cancer-associated elevation of oligomannosylation in both basal cell (p = 1.78 x 10-12) and squamous cell (p = 1.23 x 10-11) skin cancer and colorectal cancer (p = 8.0 x 10-4). The glycomics data also indicated that few cancer types including gastric and liver cancer exhibit unchanged or reduced oligomannose levels, observations also supported by literature and MALDI-MSI. Finally, data from cancer repositories indicated that three 1,2-mannosidases dictate oligomannose expression in cancer cells, and further suggested that deleterious mutations and reduced expression of MAN1A1 are key contributors to the cancer-associated oligomannose elevation. Collectively, these findings open hitherto unexplored avenues for the development of new cancer biomarkers and therapeutic targets.

biochemistry↗

bioRxiv2020

Evaluating the fitness of PA/I38T-substituted influenza A viruses with reduced baloxavir susceptibility in a competitive mixtures ferret model

Baloxavir is approved in several countries for the treatment of uncomplicated influenza in otherwise-healthy and high-risk patients. Treatment-emergent viruses with reduced susceptibility to baloxavir have been detected in clinical trials, but the likelihood of widespread occurrence depends on replication capacity and onward transmission. We evaluated the fitness of A/H3N2 and A/H1N1pdm09 viruses with the polymerase acidic I38T-variant conferring reduced susceptibility to baloxavir relative to wild-type (WT) viruses, using a competitive mixture ferret model, recombinant viruses and patient-derived virus isolates. The A/H3N2 I38T virus showed a reduction in within-host fitness but comparable between-host fitness to the WT virus, while the A/H1N1pdm09 I38T virus had broadly similar within-host fitness but substantially lower between-host fitness. Although I38T viruses replicate and transmit between ferrets, our data suggest that viruses with this amino acid substitution have lower fitness relative to WT and this relative fitness cost was greater in A/H1N1pdm09 viruses than in A/H3N2 viruses.

microbiology↗

bioRxiv2019

A CRISPR Knockout Screen Identifies Foxf1 as a Suppressor of Colorectal Cancer Metastasis That Acts Through Reduced mTOR Signalling

IntroductionA greater understanding of molecular mechanisms underlying metastasis is necessary for development of new strategies to prevent and treat cancer.\n\nMethodsWe performed a genome-wide CRISPR/Cas9 knockout screen in MC38 colorectal cancer (CRC) cells transplanted orthotopically into mice to identify genes that promote metastasis. We undertook focussed molecular analyses to identify mechanisms underlying metastasis.\n\nResultsThe screen identified several gene knockouts over-represented in lung metastases, including Dptor (mTOR signalling) and Foxf1 (gastrointestinal tumour predisposition). We validate that loss of Foxf1 promotes metastasis, increased Foxf1 expression restrained cellular migration in-vitro and human CRC metastases express lower Foxf1 than paired primary tumours. Analysis of gene expression changes downstream of Foxf1 identified increased mTOR signalling as a possible mechanism of metastasis caused by Foxf1 loss, consistent with Dptor identification. We confirmed this mechanism demonstrating that mTOR inhibitor sirolimus reduced lung metastasis burden in xenografts.\n\nConclusionMesenchymal Foxf1 plays a major role in intestinal development. We have shown for the first time, through an unbiased genetic screen, that reduced epithelial Foxf1 results in raised mTOR signalling and metastasis.\n\nAuthorship statementLennard Lee-study concept and design, acquisition of data, analysis, interpretation of data, drafting of the manuscript, statistical analysis and obtained funding. Connor Woolley-acquisition of data, analysis and interpretation of data. Thomas Starkey-acquisition of data, analysis, interpretation of data, drafting of the manuscript. Luke Freeman-Mills-interpretation of data. Andrew Bassett-technical and material support. Fanny Fanchini-technical support. Lai Mun Wang-acquisition of data and study supervision. Annabelle Lewis-study supervision. Roland Arnold-analysis, interpretation of data, statistical analysis. Ian Tomlinson-study supervision and critical revision of the manuscript.\n\nConflict of InterestThe authors whose names are listed above declare that they have no conflict of interest.

cancer biology↗

bioRxiv2019

CD2 expression acts as a quantitative checkpoint for immunological synapse structure and T-cell activation.

The CD2 receptor has been described as an adhesion and costimulatory receptor on T cells. Here, transcriptional profiling of colorectal cancers (CRC) revealed a negative correlation between CD2 expression and \"exhausted CD8+ T-cells\" gene signatures. Furthermore, we detected reduced surface CD2 levels in exhausted CD127lowPD-1hi CD3+CD8+ tumour infiltrating lymphocytes (TILs) in CRC. We describe a CD2 expression-level-dependent switch in CD2-CD58 localization between central and peripheral domains in the immunological synapse (IS). A peripheral \"CD2 corolla\" formed when CD2 surface expression was sufficiently high and its cytoplasmic domain intact. The corolla recruited other ligated receptors like CD28, boosted recruitment of activated Src-family kinases (pSrc), LAT and PLC-{gamma} in the IS and consequently T-cell activation in response to a tumour antigen. Corolla formation and pSrc in the IS increased linearly with CD2 expression, whereas pSrc signals were reduced by high, \"exhausted-like\" levels of PD-1, which invaded the corolla. These results suggest two levels of inhibition of Src-family kinases in CD3+CD8+ TILs: reduced CD2 expression and high PD-1 expression.

immunology↗