Biology subjects

Rooney, C.

Publications and source records attributed to Rooney, C..

4 recordsLinked to original sources

bioRxiv2025

The effects of elevated serum lactate on measures of apparent cerebral metabolism and perfusion in the anesthetised rodent brain.

Cerebral metabolism is coupled to perfusion and can be probed using a combination of hyperpolarized carbon-13 MRI and perfusion weighted imaging. It is unknown how alterations in serum lactate affect apparent lactate exchange and pyruvate dehydrogenase flux using hyperpolarized 13C MRI, and so this pre-clinical study was designed to assess the sensitivity of MRI to detect changes in perfusion and apparent metabolism in the anesthetized rodent brain due to sodium lactate administration. Results demonstrated significant differences in cerebral blood flow between the saline and sodium L-lactate administered at 0.5 g/kg (112 {+/-} 5 vs 127 {+/-} 2 mL/100g/min), saline and sodium L-lactate administered at 1 g/kg (112 {+/-} 5 vs 90 {+/-} 5 mL/100g/min), and between sodium L-lactate at 0.5 g/kg and sodium L-lactate at 1 g/kg (127 {+/-} 2 vs 90 {+/-} 5 mL/100g/min). There was excellent reproducibility of cerebral perfusion measurements (ICC > 0.95) between observers, indicating high reliability in these results. There were significant differences in [1-13C] lactate:[1-13C] pyruvate between saline vs 0.5 g/kg (0.22 {+/-} 0.05 vs 0.59 {+/-} 0.15) and saline vs 1 g/kg (0.22 {+/-} 0.05 vs 0.62 {+/-} 0.04), but no significant differences in 13C bicarbonate:[1-13C] pyruvate (p = 0.1). In conclusion, perfusion and [1-13C] lactate:[1-13C] pyruvate are sensitive to changes in serum lactate, but 13C bicarbonate:[1-13C] pyruvate were not. This has implications for brain studies using [1-13C] pyruvate, and understanding the impact of serum lactate on clinical hyperpolarised imaging is needed.

neuroscience↗

bioRxiv2025

Tunneling CARs: Increasing CAR T tumor infiltration through the overexpression of MMP7 and SPP1

Chimeric antigen receptor T cell (CART) therapy has demonstrated remarkable efficacy in hematologic malignancies but has struggled to achieve comparable success in solid tumors. A key obstacle is the extracellular matrix (ECM) in solid tumors, which significantly impedes CART cell infiltration. In clinical trials, neuroblastoma (NB) has shown responsiveness to GD2-directed CART therapy, however, the failure of GD2.CARTs to effectively clear bulky disease - characterized by dense ECM - highlights the critical challenge of infiltration. In this study, we demonstrate that GD2.CARTs exhibit a unique infiltration-restriction compared to other CARTs and endogenous T cells. A separate analysis of clinical datasets identified MMP7 and SPP1 (OPN) as candidate genes to improve the infiltration of GD2.CARTs as these were upregulated in tumor-infiltrating leukocytes. MMP-7 and OPN overexpression enhanced CART extravasation (p < .001) and interstitial movement (p < .05) in ECM-dense environments in vitro. Overexpression of either OPN (p < .0001) or MMP-7 (p < .001) improved tumor infiltration in a xenograft model of NB. This resulted in improved tumor control (94% reduction in tumor burden, p < .05) and a survival extension in OPN-GD2.CART treated mice compared to unmodified GD2.CARTs (median of 148 days, p < .05). OPN overexpression did not increase off-target infiltration into healthy tissues or promote tumor metastasis, highlighting its potential for safe therapeutic application. Our study provides a framework for further exploration of gene modifications to improve CART infiltration and efficacy in solid tumors and identifies SPP1 as a candidate gene to improve GD2.CART treatment of bulky tumors.

immunology↗

bioRxiv2022

CD98 is critical for a conserved inflammatory response to diverse injury stimuli relevant to IPF exacerbations and COVID pneumonitis

Progressive fibrosing interstitial lung diseases (PFILDs) cause substantial morbidity and mortality. Antifibrotic agents slow progression, but most of the clinical need remains unmet. The archetypal PFILD is idiopathic pulmonary fibrosis (IPF). Chronic progression is driven by transforming growth factor (TGF-){beta}1 signalling. It is punctuated by inflammatory flares known as acute exacerbations (AE-IPF), which are associated with accelerated decline and high mortality. We hypothesized that acute injury responses underlying exacerbations and the mechanisms of chronic fibrosis overlap at the molecular level, via a cell surface assembly nucleated by galectin-3 that we term the gal-3-fibrosome. We focused upon a putative pro-inflammatory galectin-3 ligand, the CD98:integrin complex. Our data indicate CD98 and {beta}1-integrin co-localise with galectin-3 within epithelial cells in IPF lung tissue, and within 40 nm in human lung tissue treated with TGF-{beta}1 compared to controls. CD98 is required for interleukin (IL-)6 and IL-8 responses to biochemical and biophysical conditions mimicking stimuli of AE-IPF in vivo, ex vivo and in cells, and for an interstitial neutrophilic response in a mouse model. We demonstrate this pathway progresses via intracellular influx of Ca2+ mediated by TRPV4, and NF-{kappa}B activation, operating in positive feedback. Lastly we show the CD98- and galectin-3-dependence of IL-6 and IL-8 responses to the SARS-CoV-2 spike protein receptor binding domain and the conservation of this response pattern between lung epithelial cells and monocyte-derived macrophages. Taken together our findings identify CD98 as a key mediator of both pro-fibrotic and acute inflammatory responses in the lung with relevance to AE- and chronic progression of IPF, and the priming of fibrotic lungs for acute inflammatory responses. They similarly implicate CD98 and galectin-3 as mediators of COVID pneumonitis and worse outcomes in ILD patients with COVID.

cell biology↗

bioRxiv2020

Asbestos accelerates disease onset in a genetic model of Malignant Pleural Mesothelioma

HypothesisAsbestos-driven inflammation contributes to malignant pleural mesothelioma beyond the acquisition of rate-limiting mutations. MethodsGenetically modified conditional allelic mice that were previously shown to develop mesothelioma in the absence of exposure to asbestos were induced with lentiviral vector expressing Cre recombinase with and without intrapleural injection of amosite asbestos and monitored until symptoms required euthanasia. Resulting tumours were examined histologically and by immunohistochemistry for expression of lineage markers and immune cell infiltration. ResultsInjection of asbestos dramatically accelerated disease onset and end-stage tumour burden. Tumours initiated in the presence of asbestos showed increased macrophage infiltration. Single-agent suppression of macrophages in mice with established tumours failed to extend survival. ConclusionAsbestos-driven inflammation contributes to the severity of mesothelioma beyond the acquisition of rate-limiting mutations, however, targeted suppression of macrophages alone in established disease showed no therapeutic benefit.

cancer biology↗