The Missing Link - Likely Pathogenetic Role of GM3 and Other Gangliosides in the Development of Diabetic Nephropathy

Despite scientific advances, diabetic nephropathy remains both a therapeutical challenge, and one of the major diabetic complications. Chemical structure of gangliosides, the most complex of glycosphingolipids, is characterised by one or more sialic acids and carbohydrate groups linked to a ceramide structure. Their potential pathogenetic role in a number of disorders linked to diabetes mellitus has recently been conjectured, due to evidence of their negative modulation of the insulin-mediated signaling and general effects on key cell functions like proliferation, differentiation, apoptosis, cellular signaling and adhesion. Elevated levels of advanced glycation products (AGE) usually found in diabetic conditions seem to be responsible for increased concentration of a-series gangliosides in tissues, most notably GM3. GM3 was shown to compromise the renal pericyte and mesangial cell regeneration via the inactivation of VEGF receptor and the receptor-associated Akt signaling pathway. Likewise, the lipid raft theory opened a new research area for GM3 influence, since in the glycosynapse model glycosphingolipids have a key cell-to-cell communication unit with modulating capabilities on signaling receptors. The goal of this review is to provide insight into currently available theories on proposed mechanisms that mark the GM3 as a pathophysiological mediator in the development of diabetic nephropathy

Dynamic of Circulating DNAM-1+ Monocytes and NK Cells in Patients with STEMI Following Primary Percutaneous Coronary Intervention

Although the role of inflammation and adverse cardiac remodeling in myocardial infarction (MI) have been extensively explored, gaps in knowledge on the complex interaction between these processes still exist. Data suggest that DNAX accessory molecule-1 (DNAM-1), an activating receptor implicated in NK cell education, may be involved in cardiac remodeling following coronary artery occlusion. In the present study, we aimed to explore the dynamic of DNAM-1+ monocytes and NK cells in peripheral blood in the early phase following reperfusion in patients with ST-elevation MI (STEMI). The study enrolled 49 patients older than 18 years of age diagnosed with STEMI, referred to primary percutaneous coronary intervention (pPCI). Blood samples were obtained at three distinct points (at admission, 3 h, and 24 h after pPCI) and analyzed using flow cytometry. The number of circulating DNAM-1+ monocytes (CD16++ and CD14++) and CD56dimCD16++NK cells was significantly reduced 3 h after pPCI and subsequently returned to initial levels 24 h after procedure (p = 0.003, p < 0.001, and p = 0.002, respectively). Notably, such dynamic was dependent on age of patients. A positive correlation between high sensitivity troponin I levels and number of CD16++DNAM-1+ monocytes in peripheral blood 3 h after pPCI was observed (r = 0.431, p = 0.003). In conclusion, in the present study we delineated the post-reperfusion dynamic of DNAM-1-expresing leukocytes. Additionally, we demonstrated that the number of CD16++ DNAM-1+ monocytes correlate with the extent of myocardial injury