Impaired efferocytosis by monocytes and monocyte-derived macrophages in patients with poorly controlled type 2 diabetes

Figure 1 Impaired efferocytosis function of monocytes and monocyte-derived macrophages in type 2 diabetes patients. A: Efferocytosis by monocytes in control subjects and type 2 diabetes patients determined by flow cytometry. The efferocytosis index was calculated as (number of CFSE⁺CD14⁺ monocytes/number of total CD14⁺ monocytes) × 100 (%). Data are presented as medians and quartiles or mean ± SD; B and C: Efferocytosis by monocyte-derived macrophages in control subjects and diabetic patients determined by flow cytometry or by immunofluorescence. The efferocytosis index was determined as (number of CFSE⁺CD11b⁺ monocytes/number of total CD11b⁺ monocytes) × 100 (%). The average number of efferosomes per efferocyte was calculated as the amount of efferocytosed apoptotic material per macrophage containing at least one bound or ingested apoptotic cell(s). Scale bar: 20 μm. The data are the mean ± SD. ^bP < 0.01 from paired t test (B) or unpaired t test (C), ^cP < 0.001 from the Wilcoxon matched pair test (for monocyte subsets) or paired t test (for the monocyte efferocytosis index). T2D: Type 2 diabetes.

Figure 2 Percentage of classical monocytes and macrophage CD14 expression were decreased in type 2 diabetes patients. A: Percentages of different monocyte subsets (classical, intermediate and nonclassical monocytes); B: The percentage of CD14⁺ macrophages in control subjects and diabetes patients was determined by flow cytometry; C: The median fluorescence intensity of CD14 in macrophages from control subjects and diabetes patients. The data are the mean ± SD. ^aP < 0.05, ^bP < 0.01 from paired t test. T2D: Type 2 diabetes; MFI: Median fluorescence intensity.

Figure 3 Parameters correlated with the efferocytosis index of monocytes and monocyte-derived macrophages in the total sample population. A-E: Univariate regression analysis of the relationships between each variable and the efferocytosis indices of monocytes; F-J: Monocyte-derived macrophages in the total sample population. The regression line (black line) and corresponding 95%CI (gray area) are shown for each univariate regression analysis. FPG: Fasting plasma glucose.

Figure 4 The monocyte efferocytosis index further decreased in the type 2 diabetes patients with glycosylated hemoglobin levels greater than 11. 0%. A and B: The number and percentage of monocytes, percentage of monocyte subsets; C-E: efferocytosis index of monocytes and monocyte-derived macrophages in healthy controls and in diabetes patients with glycosylated hemoglobin levels lower than 11.0% (D1) or greater than 11.0% (D2). Scale bar: 20 μm. ^aP < 0.05,^cP < 0.001 from paired t test.