An unbalanced monocyte polarisation in peripheral blood and bone marrow of patients with type 2 diabetes has an impact on microangiopathy.

AIM/HYPOTHESIS: Monocytes/macrophages play important roles in adipose and vascular tissues and can be polarised as inflammatory M1 or anti-inflammatory M2. We sought to analyse monocyte polarisation status in type 2 diabetes, which is characterised by chronic inflammation. METHODS: We enrolled 60 individuals without diabetes and 53 patients with type 2 diabetes. We quantified standard monocyte subsets defined by cluster of differentiation (CD)14 and CD16. In addition, based on the phenotype of polarised macrophages in vitro, we characterised and quantified more definite M1 (CD68(+)CCR2(+)) and M2 (CX3CR1(+)CD206(+)/CD163(+)) monocytes. We also analysed bone marrow (BM) samples and the effects of granulocyte-colony stimulating factor (G-CSF) stimulation in diabetic and control individuals. RESULTS: We found no alterations in standard monocyte subsets (classical, intermediate and non-classical) when comparing groups. For validation of M1 and M2 phenotypes, we observed that M2 were enriched in non-classical monocytes and had lower TNF-α content, higher LDL scavenging and lower transendothelial migratory capacity than M1. Diabetic patients displayed an imbalanced M1/M2 ratio compared with the control group, attributable to a reduction in M2. The M1/M2 ratio was directly correlated with waist circumference and HbA1c and, among diabetic patients, M2 reduction and M1/M2 increase were associated with microangiopathy. A decrease in M2 was also found in the BM from diabetic patients, with a relative M2 excess compared with the bloodstream. BM stimulation with G-CSF mobilised M2 macrophages in diabetic but not in healthy individuals. CONCLUSIONS/INTERPRETATION: We show that type 2 diabetes markedly reduces anti-inflammatory M2 monocytes through a dysregulation in bone-marrow function. This defect may have a negative impact on microangiopathy.

Optimized glycaemic control achieved with add-on basal insulin therapy improves indexes of endothelial damage and regeneration in type 2 diabetic patients with macroangiopathy: a randomized crossover trial comparing detemir versus glargine.

AIMS: In diabetes, endothelial damage promotes macroangiopathy and endothelial regeneration is impaired, owing to reduced endothelial progenitor cells (EPCs). Given that insulin influences endothelial biology, we compared the effects of add-on basal insulin analogues on endothelial damage and regeneration in type 2 diabetes (T2D). METHODS: This was a 6-month randomized crossover trial comparing add-on insulin detemir versus glargine in poorly controlled T2D with macroangiopathy. At baseline, crossover (3 months) and study end (6 months), we measured HbA1c, EPCs, circulating endothelial cells (CECs), VCAM-1, ICAM-1 and E-selectin. Body weight and hypoglycaemic episodes were also recorded. RESULTS: Forty-two patients completed the study, randomly assigned to the glargine-detemir (n = 21) or the detemir-glargine (n = 21) schedule. At crossover, EPC levels did not change compared with baseline, but significantly increased at study end. CECs decreased over time and were significantly reduced at study end. ICAM-1, VCAM-1 and E-selectin were significantly reduced at crossover and further decreased at study end. No differences were seen in these effects between detemir and glargine. HbA1c showed a carryover effect and its reduction was similar with detemir and glargine in the first arm. Incidence of hypoglycaemia and weight gain was lower with detemir than with glargine in both arms. CONCLUSION: Optimized glycaemic control by add-on basal insulin improved indexes of endothelial damage and regeneration. Compared to glargine, detemir achieved similar endothelial protection with lower weight gain and less hypoglycaemia. These results might have implications for therapy of aging T2D patients with cardiovascular disease.

Defective recruitment, survival and proliferation of bone marrow-derived progenitor cells at sites of delayed diabetic wound healing in mice.

AIMS/HYPOTHESIS: Bone marrow (BM)-derived endothelial progenitor cells (EPC) promote tissue healing and angiogenesis, whereas altered EPC biology may favour diabetic complications. We tested the hypothesis that diabetes impairs the contribution of BM-derived cells at sites of wound healing. METHODS: Four weeks after induction of diabetes in C57BL/6 mice, hindlimb skin wounds were created and monitored by digital imaging and histology. Circulating EPCs were quantified by flow cytometry before and after wounding. In separate experiments, bone marrow from C57BL/6 mice constitutively producing green fluorescent protein (GFP) was transplanted into myeloablated wild-type mice before induction of diabetes. We quantified proliferation, apoptosis and endothelial differentiation of tissue GFP(+) cells. Net recruitment of GFP(+) cells was estimated by correcting the number of tissue GFP(+) cells at each time point for basal levels, apoptosis and proliferation rates. RESULTS: Diabetes delayed wound healing, with reduced granulation tissue thickness and vascularity, and increased apoptosis. Circulating EPC levels were not modified by 4 week diabetes and/or skin wounding. BM-derived EPCs (GFP(+)vWf(+) [von Willebrand factor] cells) within the granulation tissue were significantly reduced in diabetic compared with control mice. BM-derived GFP(+) cells showed increased apoptosis and decreased proliferation in diabetic versus non-diabetic wound tissues. Estimated net recruitment of BM-derived GFP(+) cells was reduced on day 1 after wounding in diabetic mice. CONCLUSIONS/INTERPRETATION: Diabetic-delayed wound healing was associated with defective recruitment, survival and proliferation of BM-derived progenitor cells. Local treatments aimed at restoring EPC homing and survival might improve tissue healing in diabetes.

Low levels of endothelial progenitor cells correlate with disease duration and activity in patients with Behçet's disease.

OBJECTIVES: We tested whether Behçet's disease (BD) is characterized by alterations of circulating endothelial progenitor cells (EPCs),which are involved in vascular homeostasis and repair. METHODS: We enrolled 30 BD patients and 27 matched healthy controls. EPCs were defined and measured by flow cytometry according to the expression of CD34, CD133 and KDR. RESULTS: We show that BD patients had significantly lower levels of CD34+KDR+ and CD34+CD133+KDR+ EPCs than controls. We found significant negative correlations between EPC phenotypes and BD duration, while there were positive correlations between CD34+KDR+ EPCs and both BD activity scores and C-reactive protein. The lower EPC levels with increasing disease duration was shown in univariate analysis and in multivariable analysis adjusted for possible confounders. CONCLUSION: This is the first report that BD is associated with progressive EPC decline. Reduction of EPCs may represent a mechanism of induction and/or progression of vascular injury in these patients.

Patients with primary antiphospholipid antibody syndrome and without associated vascular risk factors present a normal endothelial function.

INTRODUCTION: Primary antiphospholipid antibody syndrome (PAPS) is characterized by venous or arterial thrombosis and positive antiphospholipid antibodies. It is controversial whether PAPS patients have early atherosclerosis. Endothelial dysfunction is an early event in the natural history of atherosclerosis. Aim of our study was to compare endothelial function of patients with PAPS and no associated risk factors with that of age- and sex-matched controls. MATERIALS AND METHODS: Patients with PAPS, carefully selected to exclude all known risk factors for cardiovascular diseases, estrogen therapy, pregnancy, intake of drugs affecting endothelial function, vitamins or antioxidants, were included in a case-control study. Controls were age- (+/-5 years) and sex-matched subjects with the same exclusion criteria but without PAPS. Flow-mediated dilation of the brachial artery and some plasmatic markers of endothelial and platelet activation were measured. Measures are expressed as mean+/-SEM. RESULTS: Twenty cases (mean age 42+/-4.0 years, 11 females) and 39 controls (mean age 41+/-2.9, 22 females) were studied. FMD was 5.7+/-0.8% in cases (95% CI: 4.1 to 7.3) and 6.8+/-0.5% (5.7 to 7.9) in controls (p=NS). Plasma von Willebrand factor was 128+/-11.3% and 134.2+/-16.1% in cases and controls, respectively (p=NS). Soluble P-selectin and soluble CD40L were 94.1+/-4.9 ng/ml and 0.7+/-0.1 ng/ml in cases and 87.7+/-4.0 ng/ml and 1.0+/-0.2 in controls, respectively (p=NS). In a substudy, circulating progenitor and mature endothelial cells were comparable between the two groups. CONCLUSIONS: Endothelial function in patients with PAPS and no associated risk factors is similar to that of age- and sex- matched controls. These data suggest that the alterations leading to thrombosis in PAPS concern primarily the clotting system.