Effects of GLP-1 receptor agonists on mitochondrial function, inflammatory markers and leukocyte-endothelium interactions in type 2 diabetes

Fig. 1. Oxidative stress parameters in PMNs from control subjects and T2D patients with or without GLP-1 RA treatment. ROS production (A), mitochondrial ROS (B) and whole-cell superoxide production (C) mitochondrial membrane potential (D) were measured by flow cytometry. Oxygen consumption was evaluated by a Clark electrode (E), and MPO protein levels (F) in serum samples from the three groups of subjects were analyzed with a Luminex® 200 analyzer system. Data are represented as mean ± SD. Comparisons were made with one –way ANOVA. *p < 0.05, **p < 0.01 and ***p < 0.001 vs Control; #p < 0.05, ##p < 0.01 vs T2D.

Fig. 2. Evaluation of leukocyte-endothelial interaction and adhesion molecules in T2D patients (treated or not with GLP-1 RA) and control subjects. Rolling velocity (A, μm/s), rolling flux (B, leukocytes/min) and adhesion (C, leukocytes/mm2). Adhesion molecules: ICAM-1 (D), VCAM-1 (E) and P-selectin (F) were measured using a Luminex® 200 analyzer system. Data are represented as mean ± SD. Results were compared between groups with one –way ANOVA. *p < 0.05 and ***p < 0.001 vs Control; #p < 0.05 vs T2D.

Fig. 3. Serum levels of cytokines and measurement of carotid intima–media thickness (CIMT). Differences between control and T2D groups (with or without GLP-1 RA treatment) are shown in the graphs. IL-6 (A), TNFα (B), IL-12 (C) and IL-10 (D) levels were measured with a Luminex® 200 analyzer system. Comparisons were made with ANOVA and a Tukey post-hoc test. *p < 0.05 and **p < 0.01 vs Control; #p < 0.05 vs T2D. Left carotid (E) and right carotid (F) were analyzed. Data are represented as mean ± SD. Statistical analysis was performed using ANOVA with a Tukey post-test. ***p < 0.001 vs Control; #p < 0.05 vs T2D.

Fig. 4. Summary of the main findings of the study. GLP-1 RA treatment in T2D patients decreases CIMT and the concentration of pro-inflammatory and adhesion molecules in circulation. GLP-1 RA also increases PMN rolling velocity, and reduces PMN rolling flux and adhesion. PMNs of patients treated with GLP-1 RA display reduced levels of ROS and improved mitochondrial membrane potential and O2 consumption, compared to patients not treated with GLP-1 RA. ΔΨm: mitochondrial membrane potential, CIMT: carotid intima–media thickness, PMN: polymorphonuclear leukocytes, ROS: reactive oxygen species. Partially created with Biorender.

Supplementary Fig. 1. Representative examples of the original plots from flow cytometry for each fluorochrome and group (corresponds to data shown in Fig. 1).