GPD2 inhibition impairs coagulation function via ROS/NF-κB/P2Y12 pathway

Area of Science:

• Epigenetics and Cardiovascular Disease
• Pharmacogenomics and Antiplatelet Therapy
• Platelet Biology and Hemostasis

Background:

• Coronary heart disease (CHD) management relies on antiplatelet therapy, with ticagrelor being a first-line agent.
• Interindividual variability in bleeding risk complicates ticagrelor efficacy, partly due to genetic factors.
• The role of modifiable epigenetic mechanisms, like DNA methylation, in platelet reactivity and bleeding risk remains underexplored.

Purpose of the Study:

• To investigate the epigenetic regulation of platelet function and bleeding risk in patients with CHD.
• To identify specific DNA methylation sites influencing gene expression, platelet function recovery, and bleeding risk.
• To elucidate the molecular mechanisms by which identified methylation sites impact platelet function and bleeding.

Main Methods:

• DNA methylation levels were measured using the 850k methylation array in 47 healthy controls and 93 CHD patients.
• Epigenome-wide association study (EWAS), summary data-based Mendelian randomization (SMR), and HEIDI analyses were employed.
• A targeted cellular model (CRISPR-dCas9-DNMT3A/Tet1CD-U6-sgRNA) and transcriptomic sequencing were used for mechanistic studies, validated in animal models.

Main Results:

• Hypermethylation at GPD2 gene promoter CpG site cg03230175 correlated with decreased GPD2 expression, delayed platelet recovery, and increased hemorrhagic risk.
• GPD2 methylation impacts mitochondrial function, NF-κB signaling, reactive oxygen species (ROS) metabolism, and GPCR ligand binding.
• Cellular models showed GPD2 methylation suppresses ROS production, NF-κB activation, and P2Y12 expression, inhibiting coagulation; animal studies confirmed GPD2 inhibition prolongs clotting time.

Conclusions:

• GPD2 gene (cg03230175) methylation reduces GPD2 expression, impairs mitochondrial energy metabolism, decreases ROS levels, and affects P2Y12 expression via the NF-κB pathway.
• This methylation ultimately inhibits coagulation function, contributing to altered bleeding risk in CHD patients.
• Findings highlight the potential of targeting GPD2 methylation for optimizing antiplatelet strategies in CHD.