Abstract LB292: Glutathione supports lipid abundance in vivo

Abstract Glutathione (GSH), the most abundant antioxidant, scavenges free radicals and prevents the detrimental effects of oxidative stress. As a result, GSH levels are associated with protection from stress-related conditions, such as aging and cancer. Given this rationale, antioxidants are routinely consumed by the public, mainly because they are viewed as “cure-alls” and almost uniformly beneficial to a range of diseases. This is an oversimplification, as the relationship between antioxidants and diseases is much more complex. Recent evidence has implicated GSH in protecting cancer cells from oxidative stress and promoting their survival. Therefore, understanding GSH metabolism in vivo and its intricate crosstalk with other cellular pathways is vital to improving the efficacy of therapies for diseases, including cancer. To interrogate this, we developed a series of in vivo models to induce Gclc deletion in adult animals. We find that GSH is essential to lipid abundance in vivo. GSH levels are reported to be highest in liver tissue, which is also a hub for lipid production. While the loss of GSH did not cause liver failure, it decreased lipogenic enzyme expression, circulating triglyceride levels, and fat stores. Mechanistically, we found that GSH promotes lipid abundance via the LXR/SREBP signaling pathway, as well as by repressing NRF2, a transcription factor induced by oxidative stress. Overall, these findings suggest an essential function for GSH in maintaining circulating lipids levels and lipid depots, possibly as a mechanism to prevent lipid peroxidation and redox imbalances. Notably, the accumulation of oxidized lipids propagates oxidative stress and associated cell death phenotypes (i.e., ferroptosis). This also highlights a potentially novel mechanism by which GSH regulates lipid production and suggests a possible link between oxidative stress (caused by GSH deficiency) and cachexia (commonly characterized by loss of fat and lean mass), a disorder linked to cancer but poorly understood. Consequently, by elucidating the contributions of GSH to lipid homeostasis, we can better understand the basic biology surrounding GSH and obtain critical insight into potentially improving the treatment of cancer-related cachexia. Citation Format: Gloria Asantewaa, Emily T. Tuttle, Nathan P. Ward, Yun P. Kang, Yumi Kim, Madeline Kavanagh, Aaron R. Huber, Joshua Munger, Benjamin Cravatt, Calvin L. Cole, Gina M. DeNicola, Isaac S. Harris. Glutathione supports lipid abundance in vivo [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr LB292.