Oxidative stress regulates the catalytic activity and mitochondrial localization of HK2 in trophoblast by regulating K346 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.