Circulating Endothelial Cells, Circulating Endothelial Progenitor Cells, and Circulating Microparticles in Type 1 Diabetes Mellitus.

BACKGROUND AND AIM:: Hyperglycemia in type 1 diabetes (T1D) is accompanied by endothelial cell dysfunction which is known to contribute to the pathogenesis of cardiovascular disorders. The aim of the current study was to explore the profile of circulating endothelial progenitor cells (EPCs), circulating endothelial cells (CECs), endothelial and platelet derived micropaticles (EMPs, PMPs) and total microparticles (TMPs), in T1D children in relation to each other and to the metabolic disorders accompanying T1D. PATIENTS AND METHODS:: Thirty T1D patients and 20 age and sex matched healthy volunteers were assessed for HbA1c level and lipid profile. Quantification of CECs, EPCs, TMPs, EMPs and PMPs was done by flow cytometry. RESULTS:: The mean levels of EMPs, PMPs, TMPs and CECs were significantly higher in diabetic children compared to controls. Meanwhile, the levels of EPCs were significantly lower in diabetic children compared to controls. Both PMPs and CECs showed the highest significant differences between patients and controls and their levels were directly related to HbA1c, total cholesterol, LDL and triglycerides. A moderate correlation was observed between the frequency of PMPs and CECs. EPCs revealed negative correlations with both LDL and triglycerides. TMPs were only related to LDL, while EMPs were only related to HbA1c. CONCLUSION:: Although there is disturbance in the levels of EMPs, PMPs, TMPs, CECs and EPCs in type 1 diabetic children compared to the controls, only the levels of PMPs and CECs were closely affected by the poor glycemic control and dyslipidemia occurring in T1D; thus may contribute to a higher risk of cardiovascular diseases.

Is Foxp3 a good marker for regulatory T cells?

To track the changes in the tested Treg markers especially Foxp3 following activation to determine whether data of human studies using Foxp3 in evaluation of Tregs are reliable or not. Four-colour flow cytometry analysis was carried out to calculate the percentages of Tregs before and after lymphocyte activation. Foxp3 expression by CD4(+)CD25(+)* and CD4(+)CD25(high) T cells increased after T cell activation. A moderate negative correlation was observed between the percentage of each of CD4(+)CD25(+)Foxp3(+)IL10(+) or CD4(+)CD25(high) Foxp3(+)IL10(+) T cells and the percentage of CD4(+)CD25(+) T cells "after activation" and a weak negative correlation was similarly observed between the percentage of CD4(+)CD25(-)Foxp3(+)IL10(+) T cells and the percentage of CD4(+)CD25(+) T cells "after activation". A moderate negative correlation was observed between the percentage of each of CD4(+)CD25(+)Foxp3(+)IL10(+), CD4(+)CD25(high)Foxp3(+)IL10(+) or CD4(+)CD25(-) Foxp3(+)lL10(+) T cells and the percentage of CD4(+)CD25(high) T cells "after activation". CD4(+)CD25(high) T cell subpopulation expressed a significantly higher level of intracellular Foxp3 compared with CD4(+)CD25(low) and CD4(+)CD25(-) T cells subpopulations. In conclusions, Foxp3 is a good marker of Tregs especially if panels of markers were used for their identification. CD4(+)CD25(high) Foxp3(+) T cell subpopulation mostly represents Tregs and thus should be the one targeted in Treg studies.