GLUT-1/PKM2 loop dysregulation in patients with non-ST-segment elevation myocardial infarction promotes metainflammation

Abstract Aims The functional capacity of the immune cells is strongly dependent on their metabolic state and inflammatory responses are characterized by a greater use of glucose in immune cells. This study is aimed to establish the role of glucose metabolism and its players [glucose transporter 1 (GLUT-1) and pyruvate kinase isozyme M2 (PKM2)] in the dysregulation of adaptive immunity and inflammation observed in patients with non-ST-segment elevation myocardial infarction (NSTEMI). Methods and results We enrolled 248 patients allocated to three groups: NSTEMI patients, chronic coronary syndromes (CCS) patients, healthy subjects (HSs). NSTEMI patients showed higher expression of GLUT-1 and an enhanced glucose uptake in T cells when compared with CCS patients (P < 0.0001; P = 0.0101, respectively) and HSs (P = 0.0071; P = 0.0122, respectively). PKM2 had a prevalent nuclear localization in T lymphocytes in NSTEMI (P = 0.0005 for nuclear vs. cytoplasm localization), while in CCS and HS, it was equally distributed in both compartments. In addition, the nuclear fraction of PKM2 was significantly higher in NSTEMI compared with HS (P = 0.0023). In NSTEMI patients, treatment with Shikonin and Fasentin, which inhibits PKM2 enzyme activity and GLUT-1-mediated glucose internalization, respectively, led to a significant reduction in GLUT-1 expression along with the down-regulation of pro-inflammatory cytokine expression. Conclusion NSTEMI patients exhibit dysregulation of the GLUT-1/PKM2 metabolic loop characterized by nuclear translocation of PKM2, where it acts as a transcription regulator of pro-inflammatory genes. This detrimental loop might represent a new therapeutic target for personalized medicine. Graphical Abstract Graphical Abstract GLUT-1/PKM2 metabolic loop and inflammatory pathways. PKM2 plays a central role in the modulation of the metabolic and inflammatory state. Our data showed aberrant localization of PKM2, in patients with NSTEMI, promoting enhanced GLUT-1 expression and glucose metabolism that shifts adaptive immunity towards a pro-inflammatory profile. The functional effects of the disruption of the metabolic loop GLUT-1/PKM2, through treatment with SKN and FSN in NSTEMI patients, led to a reduction of the pro-inflammatory profile and a modulation of the factors involved in lipid metabolism, contributing to the re-establishment of a physiological phenotype. Conversely, the treatment of HS with OLI, an inhibitor of oxidative phosphorylation, promo