Glycated High-Density Lipoproteins Reduce Endothelial Phenotypic Expression of Monocyte-Derived Multipotential Cells in Early Type 2 Diabetes

Background: High-density lipoproteins (HDL) exert protective effects on the endothelium, which are impaired in type 2 diabetes (T2D). Although monocyte-derived multipotential cells (MOMCs) can be differentiated into the endothelial lineage, it remains unclear whether HDL glycation, size, and composition could affect MOMCs differentiation. Methods: Twenty normoglycemic (49 years, 35% male), 20 prediabetic (52 years, 35% male), and 20 newly diagnosed T2D participants (51 years, 50% male) were recruited. HDL were isolated from each study group. The size, composition, and early, intermediate, or advanced glycation products of HDL were determined. CD14+ MOMCs were isolated from healthy volunteers and incubated with HDL from each group. Endothelial phenotypic expression was assessed by CD14+/KDR+ expression. Results: Compared with normoglycemic and prediabetic individuals, T2D patients had higher concentrations of early (4.4, 4.6, vs. 5.2 µmol/mg of protein, respectively; p = 0.049) and advanced (7.7, 8.7, vs. 14.3 µg-BSA-AGEs/mg of protein, respectively; p < 0.02) glycation products in HDL. HDL composition was similar among groups. The CD14+/KDR+ expression in MOMCs incubated with HDL from T2D patients was lower than that observed in prediabetes and normoglycemic individuals (46% vs. 52% and 61%, respectively; p = 0.002). Advanced glycation end products in HDL inversely correlated with CD14+/KDR+ cells (r = −0.418, p = 0.002), adjusting for other HDL characteristics. Conclusions: In T2D patients, increased HDL-advanced glycation impairs the endothelial phenotypic expression of MOMCs, independently of other HDL characteristics. Since advanced glycation leads to greater biological damage, these findings highlight the importance of preserving HDL integrity in T2D patients to support endothelial repair and potentially delay vascular complications.