Insights of mammalian hibernator-derived cholangiocyte organoids in improving liver cold preservation

Liver disease kills approximately 2 million patients worldwide per year, and liver transplantation is the best treatment for patients with end-stage liver disease. However, up to 35% of the recipients develop biliary complications, causing severe morbidity and graft failure. One major reason is that cholangiocytes are more vulnerable to cold preservation than other liver parenchymal cells. Intriguingly, during hibernation, small mammalian hibernators (e.g., Syrian hamsters) can reduce their body temperatures from ~37 ℃ normothermia to ~4 °C and protect their organs from cold stress, serving as ideal models for studying biliary cold adaptation. Here, we first demonstrated the better cold-resistance ability of Syrian hamster cholangiocytes than their mouse counterparts. Then, we successfully constructed Syrian hamster intrahepatic cholangiocyte organoids (shICOs), which could resist cooling-rewarming stress better than mouse ICOs (mICOs) could. Notably, cold stress induced evident ferroptosis in mICOs, while shICOs exhibited better anti-ferroptosis ability. Next, to identify the molecular clues of anti-ferroptosis in shICOs, we made comparison between shICOs and mICOs during cooling-rewarming process. Importantly, in addition to the moderate upregulation of Gpx4 that functions to prevent lipid peroxidation, we also detected higher expression levels of iron homeostasis related genes, such as Fth1 that encodes ferritin heavy chain and Slc40a1 that mediates the export of intracellular divalent iron. Supporting this idea, the addition of the iron chelator, deferoxamine, improved biliary cold preservation. Taken together, our findings provide unique insights into improving biliary cold preservation, and our shICO model will be a useful tool for the future study of mammalian hibernation.