Disrupting the cardiolipin oxidation-apoptosis axis: low-temperature, high-salinity depuration extends anhydrous...

This study confirmed that low-temperature, high-salinity depuration mitigates apoptosis and preserves quality in anhydrously stored Pacific oysters through targeted suppression of cardiolipin oxidation. We compared standard depuration (20 °C, 31‰) with low-temperature, high-salinity depuration (12 °C, 38‰). After five days, the latter maintained 30% higher survival, preserved glycogen and ATP equivalents, and sustained texture through suppressed serine protease activity. Integrated lipids and molecular index revealed that low-temperature, high-salinity depuration stabilized 23 cardiolipin (CL) molecular species, inhibited polyunsaturated fatty acid oxidation, and limited oxidized cardiolipin (oxCL) formation. These effects coincided with the down-regulation of pro-apoptotic genes (Bcl-2-associated X protein (Bax), Cytochrome c (Cyt-c), Caspase-3 (Casp3)) and the up-regulation of anti-apoptotic (B-cell Lymphoma 2 (Bcl-2), Heat shock protein 70 (Hsp70)) and cardiolipin synthase (Cls), Lysocardiolipin acyltransferase 1 (Lclat1)) genes, reducing mitochondrial reactive oxygen species, swelling, and mitochondrial permeability transition pore opening. Combined with time-lag correlation analysis and mediation effect analysis confirmed an oxCL-apoptosis-quality axis. Thus, low-temperature, high-salinity depuration safeguards mitochondrial integrity, delays apoptosis, and prolongs shelf life, offering a practical strategy for live oyster transport.