Increased Serum Levels of MRP-8/14 in Type 1 Diabetes Induce an Increased Expression of CD11b and an Enhanced Adhesion of Circulating Monocytes to Fibronectin
Article Figures & Tables
Figures
- FIG. 1.
Time-dependent adhesion of monocytes to FN in the absence (A) and presence (B) of fMLP. At 15 min, data represent means ± SE of 10 type 1 patients (DM1), 6 type 2 diabetic patients (DM2), and 8 healthy control subjects; at the other time points, n = 3 (Student’s t test). For 15-min data, one-way ANOVA with Bonferroni correction was used. *P < 0.05 vs. controls, #P < 0.05 vs. type 2 patients. C: Examples of spreading and stretching (−, nonstretched; +, stretched or spread). The percentage of spread and stretched cells in the different test groups at 15 min is given in D (means ± SE, same n as in A and B, one-way ANOVA with Bonferroni correction).
- FIG. 2.
CD14+CD16+ and CD14+CD16− monocyte subpopulations were sorted and purities >95% were reached. A: Representative flow cytometric analyses of starting and sorted populations. B: Adhesion to FN of both subsets was determined; differences were not observed (means ± SD, n = 3). C: Differences were also not observed among type 1 diabetic patients, type 2 diabetic patients, and healthy control subjects regarding the percentage of the CD14+CD16+ monocyte subpopulation in the peripheral blood.
- FIG. 3.
Serum levels of MRP-8 of 13 control subjects and 13 type 1 patients (A; Student’s t test), MRP-14 of 15 control subjects and 23 type 1 patients (B; Student’s t test), and MRP-8/14 in 18 control subjects, 23 type 1 patients, and 15 type 2 patients (C; one-way ANOVA). nd, not determined. A positive correlation (Spearman’s rho) was observed between MRP-14 and MRP-8/14 in the serum (D).
- FIG. 4.
A: Adhesion of healthy donor monocytes to FN after exposure to dilutions of serum samples of type 1 diabetic patients (tests were performed with 11 sera). The adhesion is expressed as a value relative to values of healthy control sera (n = 10, percentage above these controls). B: Increased adhesion of monocytes to FN by the serum samples of type 1 diabetic patients (▪, means ± SD, n = 3) and the effect of serum depletion of MRP-8/14 by monoclonal antibodies (□, means ± SD, n = 3). The experiment was carried out three times, always showing the same phenomenon by MRP-8/14 depletion. Statistics were performed using Mann-Whitney test.
- FIG. 5.
A and B: Flow cytometric analysis of the effect of MRP-8/14 in the serum of a type 1 diabetic patient on the surface expression of CD11b and CD118. The experiment was performed four times, always showing the same results by MRP-8/14. C and D: CD11b surface expression on monocytes of type 1 diabetic patients and healthy control subjects in correlation (Spearman’s rho) to the serum level of MRP-8/14 and -14.
- FIG. 6.
A representative flow cytometric analysis of the surface expression of CD11b (A), CD18 (B), CD29 (C), CD49a (D), CD49d (E), and CD49e (F) on monocytes of a type 1 diabetic patient and an age- and sex-matched healthy control subject.
Tables
- TABLE 1
Integrin expression on circulating monocytes
Integrins Fold expression* MFI type 1 diabetic patients MFI control subjects n P† CD11b αM 3.24 ± 0.52 429.44 ± 93.09 218.11 ± 59.93 20 0.002 CD18 β2 1.65 ± 0.13 122.93 ± 19.03 86.19 ± 11.45 20 0.046 CD29 β1 1.10 ± 0.03 16.64 ± 2.11 16.03 ± 1.77 20 0.930 CD49a α1 1.16 ± 0.06 7.32 ± 0.51 7.19 ± 0.54 17 0.855 CD49d α4 1.25 ± 0.08 64.27 ± 5.25 57.93 ± 4.56 21 0.273 CD49e α5 1.05 ± 0.05 77.42 ± 4.29 79.2 ± 4.47 21 0.599 Data are means ± SE. MFI, mean fluorescence intensity.
- *
* Mean fold expression relative to healthy control subjects.
- †
† Statistical significance tested using the Mann-Whitney test.
In this Issue
