Hepatic phosphatidylcholine catabolism driven by PNPLA7 and PNPLA8 supplies endogenous choline to replenish the methionine cycle with methyl groups

This in vitro and animal study explored the role of the PNPLA8-PNPLA7 enzymatic axis in hepatic phosphatidylcholine (PC) catabolism and its impact on methyl group metabolism. The study found that PNPLA7-deficient and PNPLA8-deficient mice exhibited decreased hepatic glycerophosphocholine (GPC), choline, and methionine cycle metabolites, leading to metabolic imbalances such as