PAR-4/Ca2+-calpain pathway activation stimulates platelet-derived microparticles in hyperglycemic type 2 diabetes

• Published in: Cardiovascular diabetology Vol. 20; no. 1; pp. 1 - 16
• Main Authors: Giannella, Alessandra, Ceolotto, Giulio, Radu, Claudia Maria, Cattelan, Arianna, Iori, Elisabetta, Benetti, Andrea, Fabris, Fabrizio, Simioni, Paolo, Avogaro, Angelo, Vigili de Kreutzenberg, Saula
• Format: Journal Article
• Language: English
• Published: London BioMed Central 03.04.2021; BMC
• Subjects: Angiology; Binding sites; Blood platelets; Calcium; Calpain; Cardiology; CD45 antigen; Cholesterol; Chromatography; Cytokines; Diabetes; Diabetes mellitus (non-insulin dependent); Extracellular vesicles; Flow cytometry; Glucose; Glucose tolerance; Glycated hemoglobin; Hemoglobin; Hyperglycemia; Inflammation; Intercellular adhesion molecule 1; Interleukin 6; Macrophages; Medicine; Medicine & Public Health; Metabolism; Microparticles; NF-kB; NF-κB protein; Original Investigation; Plasma; Plasma levels; Platelet activation; Platelets; Proteinase-activated receptor 1; THP-1 transformed macrophages; Thrombin; Tissue factor; Vascular cell adhesion molecule 1; Italy; Austria; Netherlands; Miami Florida; United States > US; Europe; Extracellular vesicles; NF; B; Platelet activation; THP-1 transformed macrophages; Glycated hemoglobin
• ISSN: 1475-2840; 1475-2840
• DOI: 10.1186/s12933-021-01267-w

Background Patients with type 2 diabetes (T2DM) have a prothrombotic state that needs to be fully clarified; microparticles (MPs) have emerged as mediators and markers of this condition. Thus, we investigate, in vivo, in T2DM either with good (HbA1c ≤ 7.0%; GGC) or poor (HbA1c > 7.0%; PGC) glycemic control, the circulating levels of MPs, and in vitro, the molecular pathways involved in the release of MPs from platelets (PMP) and tested their pro-inflammatory effects on THP-1 transformed macrophages. Methods In 59 T2DM, and 23 control subjects with normal glucose tolerance (NGT), circulating levels of CD62E+, CD62P+, CD142+, CD45+ MPs were determined by flow cytometry, while plasma levels of ICAM-1, VCAM-1, IL-6 by ELISA. In vitro, PMP release and activation of isolated platelets from GGC and PGC were investigated, along with their effect on IL-6 secretion in THP-1 transformed macrophages. Results We found that MPs CD62P + (PMP) and CD142 + (tissue factor-bearing MP) were significantly higher in PGC T2DM than GGC T2DM and NGT. Among MPs, PMP were also correlated with HbA1c and IL-6. In vitro, we showed that acute thrombin exposure stimulated a significantly higher PMP release in PGC T2DM than GGC T2DM through a more robust activation of PAR-4 receptor than PAR-1 receptor. Treatment with PAR-4 agonist induced an increased release of PMP in PGC with a Ca 2+ -calpain dependent mechanism since this effect was blunted by calpain inhibitor. Finally, the uptake of PMP derived from PAR-4 treated PGC platelets into THP-1 transformed macrophages promoted a marked increase of IL-6 release compared to PMP derived from GGC through the activation of the NF- k B pathway. Conclusions These results identify PAR-4 as a mediator of platelet activation, microparticle release, and inflammation, in poorly controlled T2DM.