MMP8 Promotes NETosis in Gestational Diabetes Mellitus

Background: Neutrophil extracellular traps (NETs) have been known to be involved in the gestational diabetes mellitus (GDM), but the underlying role remains poorly understood. Methods: We conducted an integrated analysis of bulk RNA-seq data, single-cell transcriptomic sequencing (scRNA-seq) data, clinical laboratory findings, and cell models to identify hub genes linked to NET formation (NETosis) and to elucidate how NETs contribute to placental injury in GDM. Results: We found that circulating NET levels were increased in pregnant women with GDM both under fasting conditions and following an oral glucose tolerance test (OGTT). Primary neutrophils isolated from healthy pregnant women produced more NETs upon high-glucose stimulation in vitro. The mRNA expression of PADI4, a key regulator of NETosis, was upregulated and positively correlated with MMP8 mRNA in patients with GDM. Inhibition of MMP8 suppressed intracellular reactive oxygen species (ROS) generation and attenuated NETosis in neutrophils. scRNA-seq analysis of placental tissues from patients with GDM identified a neutrophil subset with higher PADI4 expression. In vitro stimulation with NETs induced functional impairment of HTR8/SVneo cells. Conclusions: We uncovered that MMP8, a novel NETosis-promoting molecule, is a promising target for GDM intervention.