Oxidative stress regulates the catalytic activity and mitochondrial localization of <scp>HK2</scp> in trophoblast by regulating <scp>K346</scp> lactylation

Preeclampsia (PE) is one of the most dangerous complications of pregnancy. The pathogenic mechanisms of this condition are not yet clear. Lysine lactylation (Kla) is a novel post-translational modification (PTM) reported recently. It remains to be determined whether Kla plays a role in the development of PE. Here, western blotting revealed that the placental Kla profile of PE was different from that of normal pregnancies, and hydrogen peroxide (H₂O₂) weakened the Kla level of trophoblast cells. High-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) indicated that 333 Kla sites of 232 proteins were changed by Kla in BeWo cells (a trophoblast cell line) treated with H₂O₂, among which only HK2 showed a unique Kla site (K346) with down-regulated lactylation. Additionally, the inactive mutant HK2-K346 was associated with decreased hexokinase activity, lower affinity to voltage-dependent anion channel 1 (VDAC1), and impaired cell proliferation. These findings demonstrate that lactylation is involved in the pathogenesis of PE and that lactylation of HK2-K346 could serve as a new connection between oxidative stress, energy metabolism, and the development of PE.