Examining the role of extracellular vesicles in macrophage vitamin A release

Vitamin A plays an important role in the regulation of the immune system by impacting cell differentiation and proliferation. Previous research in our lab and in others suggests that macrophages can release vitamin A to modulate gene expression in other immune cells. However, the mechanisms by which this process occurs remain unclear. We hypothesize that extracellular vesicles (EVs) are responsible for vitamin A secretion from macrophages. To test this, we exposed murine bone marrow derived macrophages to serum enriched with vitamin A for 24 hours. After this incubation time, we washed the cells twice and exposed them to vitamin A-free medium for 6 hours to quantify the amount of vitamin A (retinol and retinyl esters) in cell lysates and media by high performance liquid chromatography. Using these experimental settings, we tested the impact inhibitors of EV secretion had on macrophage vitamin A secretion. We complemented these studies with EV isolation and purification to measure their retinoid content. HPLC analysis showed that the retinoid content of the cells and media mostly consisted of retinyl esters, with low levels of retinol. Our overall findings show that the inhibition of exosome production decreases levels of vitamin A secretion from macrophages. Additionally, isolated EVs from vitamin A treated macrophages showed elevated vitamin A levels, suggesting the involvement of exosomes in the process of vitamin A release from macrophages.

Name thesis:degree_name

M.S.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Nutritional Sciences

Grantor

University of Illinois Urbana-Champaign

Year dc:date

2025

Author dc:creator

• Xiao, Colin

Contributors dc:contributor

• Amengual, Jaume
• Erdman, John
• Cadwallader, Keith

• Vitamin A
• Macrophages
• Extracellular Vesicles

Statement dc:rights

• Copyright 2025 Colin Xiao

Language dc:language

en, eng

Handle dc:identifier

https://hdl.handle.net/2142/130206

OAI record oai:identifier

https://www.ideals.illinois.edu/oai-pmh?verb=GetRecord&metadataPrefix=etdms&identifier=oai%3Awww.ideals.illinois.edu%3A2142%2F130206