PRMT1 drives platelet metabolic reprogramming, thromboinflammation, and antiplatelet drug resistance Free

Background: Platelet hyperactivity and reduced responsiveness to antiplatelet therapies are major contributors to thrombotic complications in metabolic and inflammatory conditions such as diabetes and sepsis. These disorders are frequently accompanied by enhanced platelet activation, increased thromboxane production, and elevated thromboinflammatory responses, including cytokine release and platelet–leukocyte interactions. However, the molecular mechanisms linking these processes to platelet dysfunction remain poorly understood. Here, we identify protein arginine methyltransferase 1 (PRMT1), which is activated in diabetes and sepsis, as a central regulator that integrates metabolic, transcriptional, and inflammatory pathways to promote platelet hyperactivity, thromboinflammation, and resistance to antiplatelet agents.

Methods: Using megakaryocyte-specific PRMT1 overexpression (Pf4-cre PRMT1 transgenic mice) and knockout mice (Pf4-cre Prmt1^flox/floxmice).

Results: PRMT1 enhanced thrombin-mediated platelet aggregation by aggregometer assays and bioflux assays, and accelerates clot formation in tail bleeding assays. Consistently, Prmt1 knockout mice exhibited a prolong bleeding time and poor performance in platelet aggregation assays. Recently, we have published that PRMT1 promotes aerobic glycolysis and attenuates respiratory complex 2 activity, which leads to an accumulation of succinate and a higher ADP/ATP ratio (Su et al. 2025). While extracellular succinate enhanced activation in wild-type platelets, it failed to augment PRMT1-high platelet activation, suggesting a saturated or bypassed succinate-GPR91 axis in these platelets. Mechanistically, PRMT1 upregulated TBXAS1, the gene encoding thromboxane synthase, via transcription factors SOX4 and RUNX1 in megakaryocytes. The resulting platelets had an increased thromboxane A2 (TXA2) production ability, making additional succinate stimulation unnecessary. Interestingly, PRMT1-high platelets cannot respond to P2Y12 inhibition with prasugrel due to PRMT1-mediated attenuation of mitochondrial respiratory capability. PRMT1 facilitates the maturation of inflammatory cytokine mRNAs (e.g., IL-1β) through RBM15-mediated splicing (Zhang et al. 2015). Given that normal platelets contain proinflammatory cytokines in pre-mRNA form, upregulated of PRMT1 in megakaryocytes leads to producing platelets with mature mRNAs enabling rapid cytokine translation upon activation. Proteomic profiling of platelets from the transgenic mice further validated the enrichment of inflammatory and antigen presentation pathways in PRMT1-high platelets.We further demonstrated the enhanced platelet–neutrophil interactions and NET formation using purified platelets and neutrophils.

Dusp4 is a downstream target of PRMT1 through methylation. After methylation, Dusp4 protein is degraded via ubiquitylation. Thus, we also found the hyperactivation in platelets from the DUSP4+/- mice. Since DUSP4 knockout mice are supceptible for Leishmania infection, our data suggest that PRMT1-Dusp4 axis may be important for fighting leishmania infection or other infection. To investigate platelet heterogeneity, we added a PRMT1-specific vital dye E84 (Su et al., Blood Adv., 2018) in FACS analysis. We found that PRMT1 expression varied across the platelet pool. In diabetic mice, E84 staining detected a wider range of PRMT1 expression in platelets, supporting a link between metabolic disease and prothrombotic platelet phenotypes. Surprisingly, even in PRMT1 transgenic or knockout mice, PRMT1 heterogeneity persisted, suggesting an incomplete flox recombination reaction during megakaryopoiesis and potential lineage memory effects.Conclusion: Together, These findings elucidate a novel mechanism underlying platelet hyperactivity and antiplatelet resistance in metabolic diseases, and identify PRMT1 as a potentially promising therapeutic target in thromboinflammatory disorders.