Biology subjects

Webster, N. J. G.

Publications and source records attributed to Webster, N. J. G..

5 recordsLinked to original sources

bioRxiv2025

Multi-omics profiling reveals microenvironmental remodeling as a key driver of house dust mite-induced lung cancer progression

Chronic exposure to the common aeroallergen house dust mite (HDM) induces lung inflammation and DNA damage, but its impact on lung cancer development remains largely unexplored. Using whole-genome sequencing, RNA-seq, and DNA methylation profiling, we assessed HDM effects in lung epithelial cell lines and a mouse orthotopic lung cancer model. HDM accelerated tumor growth without altering mutational burden. Transcriptomic and epigenetic analyses revealed tissue-specific effects: in normal lung, HDM enhanced pro-inflammatory and immune activation programs, whereas in tumors it suppressed T cell responses, antigen presentation, and chemokine signaling. Immune deconvolution showed a shift toward myeloid enrichment and lymphoid suppression, with reduced cytotoxic T and NK signatures. Notably, HDM-driven tumor promotion was abolished in Il17a-/- but not Il1b-/-mice, identifying IL-17A as a critical mediator. These findings demonstrate that chronic aeroallergen exposure reshapes the lung microenvironment to promote immune suppression and accelerate lung cancer progression. HighlightsChronic house dust mite (HDM) exposure accelerates lung tumor growth through non-mutagenic, immune-mediated mechanisms. HDM activates pro-inflammatory and immune programs in normal lung tissue but suppresses antitumor T cell responses in tumors. Multi-omics profiling reveals epigenetic silencing of immune genes and a myeloid-enriched, lymphoid-deficient tumor microenvironment. HDM-driven tumor promotion depends on IL-17A but not IL-1{beta}, establishing IL-17A as a central driver of lung tumor promotion.

cancer biology↗

bioRxiv2025

SRSF3 is oncogenic in breast but tumor-suppressive in liver by differential regulation of gene expression

SRSF3 (SRp20) is an essential splicing factor. We discovered Srsf3 plays an oncogenic role in breast cancer and Srsf3 knockout (KO) in mammary glands delays the development of breast cancer in an Erbb2 mouse model. In contrast, Srsf3 is tumor-suppressive in mouse liver tissues. Srsf3 KO in hepatocytes enhances DEN-induced liver cancer and disrupts the sex disparity in DEN-induced liver cancer. Comparing to Srsf3 WT liver cancer, Srsf3 KO significantly increases Sox4, E2f1, Trpv4, Trim6, and Myc expression, but does not so in Erbb2 breast cancer. Srsf3 KO inhibits expression of Mfsd4a and Eif4a2 in breast cancer but enhances Mfsd4a and Eif4a2 expression in liver cancer. Moreover, Srsf3 KO suppresses the expression of ER and Foxa genes to reduce Lifr and Egfr but induce Myc expression and promote liver cancer in female mice. Together, our data highlight a new functional paradigm of SRSF3 at its physiological level in tissue context-dependent gene regulation.

cancer biology↗

bioRxiv2022

Gnas ablation in CD11c+ cells prevents high-fat diet-induced obesity by elevating adipose tissue catecholamine levels and thermogenesis

CD11c+ immune cells are a potential therapeutic target for treatment of obesity-related insulin resistance and type 2 diabetes (T2D). In obesity, CD11c+ immune cells are recruited to white adipose tissue and create an inflammatory state that causes both insulin and catecholamine resistance. In this study, we found that ablation of Gnas, the gene that encodes Gas, in CD11c expressing cells protects mice from high-fat diet-induced obesity, glucose intolerance and insulin resistance. Gnas{Delta}CD11c mice (KO) had increased oxygen consumption, energy expenditure, and beigeing of white adipose tissue (WAT). Transplantation studies showed that the lean phenotype was conferred by bone marrow-derived cells and the absence of T and B cells by crossing the KO to a Rag1-/- background did not alter the phenotype. Notably, we observed elevated norepinephrine and elevated cAMP signaling in the WAT of KO mice. The KO adipose tissue also had reduced expression of catecholamine transport and degradation enzymes. Collectively, our results identified an important role of Gas in CD11c+ cells in whole body metabolism regulation by controlling norepinephrine levels in WAT, modulating catecholamine-induced lipolysis and increasing thermogenesis that together created a lean phenotype.

immunology↗

bioRxiv2020

Catestatin reduces hyperglycemia in insulin-resistant mice by redirecting glucose-6-phosphate from the gluconeogenic to the glycogenic pathway

AimDefects in hepatic glycogen synthesis contribute to postprandial hyperglycemia in type 2 diabetic (T2D) patients. Chromogranin A (CgA) peptide Catestatin (CST: hCgA352-372) has been shown to improve glucose tolerance in insulin-resistant mice. Here, we seek to determine whether CST also reduces hyperglycemia by increasing hepatic glycogen synthesis. MethodsWe determined liver glycogen, glucose-6-phosphate (G6P), uridine diphosphate glucose (UDPG), and glycogen synthase (GYS2) activities; plasma insulin, glucagon, norepinephrine (NE), and epinephrine (EPI) levels in fed and fasted liver of lean and obese mice as well as in CST knockout (CST-KO) mice after treatments with saline, CST, or insulin. We also determined glycogen synthesis and glycogenolysis in primary hepatocytes. In addition, we analyzed phosphorylation signals of Insulin receptor (IR), insulin receptor substrate-1 (IRS-1), phosphatidylinositol dependent kinase-1 (PDK-1), GYS2, glycogen synthase kinase-3{beta} (GSK-3{beta}), AKT (an enzyme in AKR mouse that produces Thymoma)/PKB (protein kinase B) and mTOR (mammalian/mechanistic target of rapamycin) by immunoblotting. ResultsCST stimulated glycogen accumulation in fed and fasted liver and in primary hepatocytes. CST reduced plasma NE and EPI levels, suggesting that CST promotes glycogenesis by inhibiting catecholamine-induced glycogenolysis. CST also directly stimulated glycogenesis and inhibited NE and EPI-induced glycogenolysis in hepatocytes. CST elevated the levels of UDPG and increased GYS2 activity, thus redirecting G6P to the glycogenic pathway. CST-KO mice had decreased liver glycogen that was restored by treatment with CST, reinforcing the crucial role of CST in hepatic glycogenesis. CST can improve insulin signals downstream of insulin receptor IR and IRS-1 by enhancing phospho-AKT signals through stimulation of PDK-1 and mTORC2 (mTOR complex 2) activities. ConclusionsWe conclude that CST directly promotes the glycogenic pathway and reduces plasma glucose levels in insulin-resistant mice by (i) reducing glucose production, (ii) increasing glycogen synthesis from UDPG, and (iii) reducing glycogenolysis. This is achieved by enhancing downstream insulin signaling.

physiology↗

bioRxiv2019

Inhibition of IRF4 in dendritic cells by PRR-independent and -dependent signals inhibit Th2 and promote Th17 responses

Cyclic AMP (cAMP) is involved in multiple biological processes. However, little is known about its role in shaping immunity. Here we show that cAMP-PKA-CREB signaling (a pattern recognition receptor [PRR]-independent) regulates conventional type-2 Dendritic Cells (cDC2s), but not cDC1s and reprograms their Th17-inducing properties via repression of IRF4 and KLF4, transcription factors (TFs) for Th2 induction. Genetic loss of IRF4 phenocopies the effects of cAMP signaling on Th17-induction, indicating that the cAMP effect is secondary to repression of IRF4. Moreover, signaling in cDC2s by a PRR-dependent microbial product, curdlan, represses IRF4 and KLF4, resulting in a pro-Th17 phenotype. These results define a novel signaling pathway by which cDC2s display plasticity and provide a new molecular basis for the novel cDC2 and cDC17 classification. In addition, the data reveal that cAMP signaling can alter DCs function and fate by repressing IRF4 and KLF4, a pathway that can be harnessed for immuno-regulation.

immunology↗