Serum soluble endothelial-cell specific adhesion molecules in children with insulin-dependent diabetes mellitus

The role of endothelial cell adhesion molecules P-selectin, E-selectin and intercellular adhesion molecule-1 in leucocyte recruitment induced by exogenous methylglyoxal

Methylglyoxal (MG) is a reactive dicarbonyl metabolite formed during glucose, protein and fatty acid metabolism. In hyperglycaemic conditions, increased MG level has been linked to the development of diabetes and its vascular complications at the macrovascular and microvascular levels where inflammation plays a role. To study the mechanism of MG-induced inflammation in vivo, we applied MG locally to healthy mice and used intravital microscopy to investigate the role of endothelial cell adhesion molecules in MG-induced leucocyte recruitment in cremasteric microvasculature. Administration of MG (25 and 50 mg/kg) to the tissue dose-dependently induced leucocyte recruitment at 4.0-5.5 hr, with 84-92% recruited cells being neutrophils. Such MG treatment up-regulated the expression of endothelial cell adhesion molecules P-selectin, E-selectin, intercellular adhesion molecule-1, but not vascular cell adhesion molecule-1. Activation of the nuclear factor-κB signalling pathway contributed to MG-induced up-regulation of these adhesion molecules and leucocyte recruitment. The role of the up-regulated endothelial cell adhesion molecules in MG-induced leucocyte recruitment was determined by applying specific functional blocking antibodies to MG-treated animals and observing changes in leucocyte recruitment parameters. Our data demonstrate that the up-regulation of P-selectin, E-selectin and intercellular adhesion molecule-1 contributes to the increased leucocyte rolling flux, reduced leucocyte rolling velocity, and increased leucocyte adhesion, respectively. Our results reveal the role of endothelial cell adhesion molecules in MG-induced leucocyte recruitment in microvasculature, an inflammatory condition related to diabetic vascular complications.

Elevated E-selectin and diastolic blood pressure in diabetic children

BACKGROUND

Cardiovascular risk markers are related to micro-angiopathy in children with type 1 diabetes (T1DM), but there is no information about their relationship with blood pressure (BP) and endothelial function.

MATERIALS AND METHODS

This was a case-control study including 29 children with T1DM (mean age 10·5 ± 2·7 years, disease duration: 3·8 ± 2·2 years) and 39 healthy controls (mean age: 9·8 ± 2·7 years). We assessed 24-h ambulatory BP, vascular function and serum level of lipids, vascular cell adhesion molecule-1 (VCAM-1; ICAM) and selectins (E-selectin; P-selectin).

RESULTS

The subject groups had similar physical characteristics and lipids level, except body mass index (BMI) which was higher in T1DM than in healthy children (18·6 ± 2·6 vs. 16·7 ± 2·5 kg/m(2), P = 0·003). Children with T1DM had increased 24 h diastolic BP z-score (0·62 ± 0·9 vs. -0·65 ± 0·8, P < 0·001), even after adjustment for BMI, as well as higher VCAM-1 concentration (492 ± 346 vs. 340 ± 225 ng/mL, P = 0·039) compared to healthy subjects. Diastolic BP z-scores were associated with disease duration, E-selectin and triglyceride levels in the T1DM group (P < 0·05). E-selectin was also related to triglycerides, otherwise there were no relationships between vascular function, markers and BP.

CONCLUSION

E-selectin, an early atherosclerosis biomarker, is positively associated with diastolic BP values in children with T1DM, despite relatively short disease duration.

Diabetic ketoacidosis-associated stroke in children and youth

Diabetic ketoacidosis (DKA) is a state of severe insulin deficiency, either absolute or relative, resulting in hyperglycemia and ketonemia. Although possibly underappreciated, up to 10% of cases of intracerebral complications associated with an episode of DKA, and/or its treatment, in children and youth are due to hemorrhage or ischemic brain infarction. Systemic inflammation is present in DKA, with resultant vascular endothelial perturbation that may result in coagulopathy and increased hemorrhagic risk. Thrombotic risk during DKA is elevated by abnormalities in coagulation factors, platelet activation, blood volume and flow, and vascular reactivity. DKA-associated cerebral edema may also predispose to ischemic injury and hemorrhage, though cases of stroke without concomitant cerebral edema have been identified. We review the current literature regarding the pathogenesis of stroke during an episode of DKA in children and youth.

Anti-inflammatory properties of C-Peptide

C-peptide, historically considered a biologically inactive peptide, has been shown to exert insulin-independent biological effects on a number of cells proving itself as a bioactive peptide with anti-inflammatory properties. Type 1 diabetic patients typically lack C-peptide, and are at increased risk of developing both micro- and macrovascular complications, which account for significant morbidity and mortality in this population. Inflammatory mechanisms play a pivotal role in vascular disease. Inflammation and hyperglycemia are major components in the development of vascular dysfunction in type 1 diabetes. The anti-inflammatory properties of C-peptide discovered to date are at the level of the vascular endothelium, and vascular smooth muscle cells exposed to a variety of insults. Additionally, C-peptide has shown anti-inflammatory properties in models of endotoxic shock and type 1 diabetes-associated encephalopathy. Given the anti-inflammatory properties of C-peptide, one may speculate dual hormone replacement therapy with both insulin and C-peptide in patients with type 1 diabetes may be warranted in the future to decrease morbidity and mortality in this population.