Biology subjects

Lancaster, G. I.

Publications and source records attributed to Lancaster, G. I..

3 recordsLinked to original sources

bioRxiv2026

A diet enriched in highly poly-unsaturated fatty acids alters immune cell lipid composition and ferroptosis susceptibility

Ferroptosis is a regulated form of cell death that is dependent upon the peroxidation of phospholipids containing poly-unsaturated fatty acids (PL-PUFAs), particularly those with 4 or more double bonds. PL-PUFA content is dramatically different between immune cell types which directly influences their sensitivity to ferroptosis. Modulating the PL-PUFA content of various cells is becoming an attractive approach to increase the efficacy of therapies designed to target ferroptosis. In this study we aimed to determine whether a diet enriched in highly unsaturated PUFAs alters immune cell lipid composition and, consequently, the susceptibility to ferroptosis. To address this, mice were fed either a diet enriched in eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) (High PUFA diet) or a standard control diet (Control diet) for eight weeks. Immune cells were then isolated from the bone marrow, blood, and lymph nodes for lipidomic analysis and sensitivity to ferroptosis. The High PUFA diet resulted in the widespread incorporation of EPA and DHA into multiple PL species across all immune cell types. However, the magnitude of incorporation differed between cell populations, with B cells exhibiting the greatest enrichment in PL-PUFA-EPA and PL-PUFA-DHA species, followed by monocytes and neutrophils, while T cells showed the lowest degree of enrichment. Importantly, these compositional changes were associated with increased susceptibility to ferroptosis in a cell and location specific manner. Collectively, these findings demonstrate that a diet enriched in highly unsaturated PUFAs increases PL-PUFAs in immune cells and broadly enhances immune cell susceptibility to ferroptosis. Therefore, altering dietary fatty acid composition may represent a strategy to influence ferroptosis sensitivity in conditions where either inducing or inhibiting ferroptosis is therapeutically desirable.

cell biology↗

bioRxiv2023

An immune cell lipid atlas reveals the basis of susceptibility to ferroptosis

The cellular lipidome is comprised of thousands of unique lipid species. This complexity underpins the many roles of lipids in cellular biology. How lipidome composition varies between cell types and how such differences contribute to cell-specific functionality is poorly understood. Here, using mass spectrometry-based targeted lipidomics, we have characterised the cellular lipid landscape of the human and mouse immune systems (www.cellularlipidatlas.com). We find that myeloid and lymphoid cell lineages have unique lipid compositions, notably in the usage of ester and ether bonds within glycerophospholipids (PLs) and PL acyl chain composition. To determine if immune cell-specific lipid phenotypes promote cell-specific functional properties we focused on differences in poly-unsaturated fatty acid (PUFA)-containing PL, the levels of which are markedly higher in lymphoid cells relative to myeloid cells. We firstly show that differences in PUFA-PL content provides a mechanistic basis for previously described differences in immune cell susceptibility to ferroptosis, a form of cell death driven by iron-dependent lipid peroxidation, and secondly, that the low PUFA-PL content of neutrophils restrains NADPH oxidase-driven ferroptosis. In summary, we show that the lipid landscape is a defining feature of immune cell identity and that cell-specific lipid phenotypes underpin aspects of immune cell physiology.

cell biology↗

bioRxiv2021

Detailed metabolic phenotyping of four tissue specific Cas9 transgenic mouse lines

CRISPR/Cas9 technology has revolutionized gene editing and fast tracked our capacity to manipulate genes of interest for the benefit of both research and therapeutic applications. Whilst many advances have, and continue to be made in this area, perhaps the most utilized technology to date has been the generation of knockout cells, tissues and animals by taking advantage of Cas9 function to promote indels in precise locations in the genome. Whilst the advantages of this technology are many fold, some questions still remain regarding the effects that long term expression of foreign proteins such as Cas9, have on mammalian cell function. Several studies have proposed that chronic overexpression of Cas9, with or without its accompanying guide RNAs, may have deleterious effects on cell function and health. This is of particular concern when applying this technology in vivo, where chronic expression of Cas9 in tissues of interest may promote disease-like phenotypes and thus confound the investigation of the effects of the gene of interest. Although these concerns remain valid, no study to our knowledge has yet to demonstrate this directly. Thus, in this study we used the lox-stop-lox (LSL) spCas9 ROSA26 transgenic (Tg) mouse line to generate four tissue-specific Cas9-Tg models with expression in the heart, liver, skeletal muscle and adipose tissue. We performed comprehensive phenotyping of these mice up to 20-weeks of age and subsequently performed molecular analysis of their organs. We demonstrated that Cas9 expression in these tissues had no detrimental effect on whole body health of the animals, nor did it induce any tissue-specific effects on energy metabolism, liver health, inflammation, fibrosis, heart function or muscle mass. Thus, our data suggests that these models are suitable for studying the tissue specific effects of gene deletion using the LSL-Cas9-Tg model, and that phenotypes observed utilizing these models can be confidently interpreted as being gene specific, and not confounded by the chronic overexpression of Cas9.

molecular biology↗