Lipid phase transitions in cat oocytes supplemented with deuterated fatty acids.

Autor:	Okotrub KA; Institute of Automation and Electrometry, the Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia. Electronic address: okotrub@iae.nsk.su., Okotrub SV; Institute of Automation and Electrometry, the Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia; Institute of Cytology and Genetics, the Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia., Mokrousova VI; Institute of Automation and Electrometry, the Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia; Institute of Cytology and Genetics, the Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia., Amstislavsky SY; Institute of Cytology and Genetics, the Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia., Surovtsev NV; Institute of Automation and Electrometry, the Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia.
Jazyk:	angličtina
Zdroj:	Biophysical journal [Biophys J] 2021 Dec 21; Vol. 120 (24), pp. 5619-5630. Date of Electronic Publication: 2021 Nov 10.
DOI:	10.1016/j.bpj.2021.11.008
Abstrakt:	Cryopreservation of oocytes has already been used to preserve genetic resources, but this technology faces limitations when applied to the species whose oocytes contain large amounts of cytoplasmic lipid droplets. Although cryoinjuries in such oocytes are usually associated with the lipid phase transition in lipid droplets, this phenomenon is still poorly understood. We applied Raman spectroscopy of deuterium-labeled lipids to investigate the freezing of lipid droplets inside cat oocytes. Lipid phase separation was detected in oocytes cryopreserved by slow-freezing protocol. For oocytes supplemented with stearic acid, we found that saturated lipids form the ordered phase being distributed at the periphery of lipid droplets. When an oocyte is warmed to physiological temperatures after cooling, a fraction of saturated lipids may remain in the ordered conformational state. The fractions of monounsaturated and polyunsaturated lipids redistribute to the core of lipid droplets. Monounsaturated lipids undergo the transition to the ordered conformational state below -10°C. Using deuterated fatty acids with a different number of double bonds, we reveal how different lipid fractions are involved in the lipid phase transition of a cytoplasmic lipid droplet and how they can affect cell survival. Raman spectroscopy of deuterated lipids has proven to be a promising tool for studying the lipid phase transitions and lipid redistributions inside single organelles within living cells. (Copyright © 2021 Biophysical Society. Published by Elsevier Inc. All rights reserved.)
Databáze:	MEDLINE
Externí odkaz:	Zobrazit plný text záznamu