20.500.12556/DiRROS-27956 Opposing roles of DGAT-mediated lipid droplet biogenesis in the regulation of ferroptosis sensitivity Lipid droplets (LDs) are dynamic fat storage organelles involved in fatty acid metabolism, signaling, and trafficking. By storing polyunsaturated fatty acids (PUFAs) in the form of neutral lipids, LDs can either mitigate or exacerbate lipotoxic damage. However, their role in regulating cellular fatty acid distribution, membrane unsaturation, and ferroptosis susceptibility remains poorly understood. Here, we show that inhibition of diacylglycerol acyltransferase (DGAT)-mediated LD biogenesis in PUFA-supplemented triple-negative breast cancer cells triggers widespread lipidome reorganization and membrane phospholipid acyl-chain remodeling, promoting lipid peroxidation and ferroptosis sensitivity. Lipidomic analyses reveal that LDs efficiently sequester exogenous PUFAs within triacylglycerols and cholesteryl esters, significantly altering neutral lipid unsaturation profiles. When LD formation is impaired by DGAT inhibition, PUFAs are redistributed into membrane ester and ether glycerophospholipids, enhancing overall membrane unsaturation, lipid peroxidation, and increasing ferroptosis susceptibility, even in the absence of additional ferroptosis inducers. In contrast, in human lung adenocarcinoma cells, LDs exhibit a dual, context-dependent role in ferroptosis regulation, whereby exogenous PUFA levels and the extent of ferroptosis protection determine whether DGAT inhibition promotes or protects against cell death. The pro-ferroptotic function of LDs predominates in these cells and is strongly enhanced by ferroptosis suppressor protein 1 (FSP1) deficiency, which amplifies lipid peroxidation within LDs and promotes its propagation to other cellular compartments. This study highlights LDs as multifaceted regulators of ferroptosis, interlinking metabolic and redox quality control mechanisms. lipid droplets ferroptosis lipidomics lipidomics lipidne kapljice feroptoza true false true Wiley Združeno kraljestvo Angleški jezik Slovenski jezik © 2026 The Author(s). Neznano 2026-03-02 13:05:21 2026-03-02 13:05:21 2026-03-03 03:52:36 0000-00-00 00:00:00 2026 0 0 Nasl. z nasl. zaslona; Soavtorji iz Slovenije: Leja Perne, Špela Koren, Eva Jarc Jovičić, Nastja Feguš, Carina Pinto Kozmus, Toni Petan; Opis vira z dne 2. 3. 2026; str. 1-25 iss. Vol. 293 [in press] 2026 0000-00-00 Zaloznikova Objavljeno NiDoloceno 2025-05-08 2026-02-10 2026-02-23 577 1742-4658 10.1111/febs.70467 270092291 https://febs.onlinelibrary.wiley.com/doi/10.1111/febs.70467 1 1aab62c0-1630-11f1-8c73-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=41187 RAZ_Kump_Ana_2026.pdf RAZ_Kump_Ana_2026.pdf 1 1C2E97ADB68C1771F57E9C63CE77830F b5eb449bcb6c0351f1ed7f1a36c06f3345ded75ca65f1368606836a08cfb59cf 7b4a2d1d-1638-11f1-8c73-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=41190 Institut Jožef Stefan 0 0 0