Fucoidan/VEGF-based surface modification of decellularized pulmonary heart valve improves the antithrombotic and re-endothelialization potential of bioprostheses.

Decellularized porcine heart valves offer promising potential as biocompatible prostheses. However, this procedure alter matrix fibres and glycans, leading to lower biomechanical resistance and increased their thrombotic potential. Therefore, their durability is limited due to calcification and weak regeneration in vivo. Surface modifications are highly requested to improve the scaffolds re-endothelialization required to restore functional and haemocompatible heart valve. Fucoidan, a natural sulphated polysaccharide, carries antithrombotic and anti-inflammatory properties and is known to enhance endothelial adhesion and proliferation when associated with vascular endothelial growth factor (VEGF). Based on these features, we constructed fucoidan/VEGF polyelectrolyte multilayer film (PEM) coated valve scaffold in an attempt to develop functional heart valve bioprosthesis. We investigated the haemocompatibility of the PEM coated valve scaffolds, the adhesion and growth potential of endothelial cells (HUVECs) in flow, as well as long term culture with stem cells. Fucoidan/VEGF PEM coated scaffolds demonstrated antithrombotic and non-calcifying properties. The PEM application increased HUVECs adhesion in flow (6 h) and HUVECs viability over time (72 h). HUVECs were well spread and aligned in flow direction. Interestingly, stem cells infiltration was improved by the PEM coating at 21 days. Thus, the fucoidan/VEGF PEM is a promising surface modification to obtain valve bioprostheses for clinical applications with increased antithrombotic and re-endothelialization potential.

Pro-angiogenic effect of RANTES-loaded polysaccharide-based microparticles for a mouse ischemia therapy.

Peripheral arterial disease results from the chronic obstruction of arteries leading to critical hindlimb ischemia. The aim was to develop a new therapeutic strategy of revascularization by using biodegradable and biocompatible polysaccharides-based microparticles (MP) to treat the mouse hindlimb ischemia. For this purpose, we deliver the pro-angiogenic chemokine Regulated upon Activation, Normal T-cell Expressed and Secreted (RANTES)/CCL5 in the mouse ischemic hindlimb, in solution or incorporated into polysaccharide-based microparticles. We demonstrate that RANTES-loaded microparticles improve the clinical score, induce the revascularization and the muscle regeneration in injured mice limb. To decipher the mechanisms underlying RANTES effects in vivo, we demonstrate that RANTES increases the spreading, the migration of human endothelial progenitor cells (EPC) and the formation of vascular network. The main receptors of RANTES i.e. CCR5, syndecan-4 and CD44 expressed at endothelial progenitor cell surface are involved in RANTES-induced in vitro biological effects on EPC. By using two RANTES mutants, [E66A]-RANTES with impaired ability to oligomerize, and [44AANA47]-RANTES mutated in the main RANTES-glycosaminoglycan binding site, we demonstrate that both chemokine oligomerization and binding site to glycosaminoglycans are essential for RANTES-induced angiogenesis in vitro. Herein we improved the muscle regeneration and revascularization after RANTES-loaded MP local injection in mice hindlimb ischemia.

Relationships between adipokines, biomarkers of endothelial function and inflammation and risk of type 2 diabetes.

AIMS: Identification of novel biomarkers of diabetes risk help to understand mechanisms of pathogenesis and improve risk prediction. Our objectives were to examine the relationships between adipokines, biomarkers of inflammation and endothelial function and development of type 2 diabetes; and to assess the relevance of including these biomarkers in type 2 diabetes prediction risk models. METHODS: 1345 subjects from the SU.VI.MAX study, who were free of diabetes at baseline and who completed 13 years of follow-up were included in the present analyses. Odds ratios (OR) with 95% confidence intervals (95% CI) of incident type 2 diabetes associated with a 1-SD increase in adiponectin, leptin, C-reactive protein (CRP), soluble intracellular adhesion modecule-1 (sICAM-1), soluble vascular cell adhesion molecule 1 (sVCAM-1), E-selectin and monocyte chemoattractant protein-1 (MCP-1) were estimated. Predicitive performances of models including biomarkers were assessed with area under the receiver operating curves (AUC) and integrated discrimination improvement (IDI) statistics. RESULTS: 82 subjects developed type 2 diabetes during follow-up. The risk of developing type 2 diabetes increased with increasing concentrations of leptin (2.04 (1.28;3.26)), sICAM-1 (1.39 (1.08;1.78)) and sVCAM-1 (1.29 (1.01;1.64)). Type 2 diabetes associations with leptin remained significant after adjusting for a combination of biomarkers. Models adjusted for novel biomarkers had improved performance compared to models adjusted for classical risk factors as assessed by IDI, but not by AUC. CONCLUSIONS: Adipokines, biomarkers of inflammation and endothelial function were significantly associated to onset of type 2 diabetes. However their inclusion in predictive scores is not supported by the present study.

Haemoglobin glycation may partly explain the discordance between HbA1c measurement and oral glucose tolerance test to diagnose dysglycaemia in overweight/obese subjects.

AIM: This study assessed whether the poor correlation between HbA1c and oral glucose tolerance test (OGTT) for dysglycaemia diagnosis may be explained by haemoglobin glycation (HbG). METHODS: A total of 1033 consecutive overweight or obese patients with no known diabetes underwent OGTT and measurement of HbA1c to diagnose diabetes and dysglycaemia (American Diabetes Association criteria). For each OGTT result category, low, medium and high HbG was defined according to the mean HbA1c/fructosamine ratio and mean fructosamine. High HbG was defined as values greater than mean values in each OGTT category for both HbA1c/fructosamine ratio and fructosamine levels, and low HbG was defined as lower values of both. The remaining patients were considered medium HbG. RESULTS: Based on OGTT and HbA1c values, 267 (25.8%) and 443 (42.8%) patients had intermediate hyperglycaemia, and 66 (6.4%) and 95 (9.2%) patients had diabetes, respectively. The results were discordant for intermediate hyperglycaemia or diabetes diagnosis in 41.7% and for diabetes diagnosis in 10.0% of the patients. The proportion of patients with HbA1c≥6.5%, but without OGTT-diagnosed diabetes, was 0%, 3.8% and 32.8% in the low-HbG, medium-HbG and high-HbG groups, respectively. In contrast, the proportion of patients with HbA1c<5.7%, but with an abnormal OGTT, was 30.4%, 11.1% and 0%, respectively. The AUROC of HbA1c to detect OGTT-diagnosed diabetes was better in the medium-HbG group [0.874 (0.816-0.931)] than in those with low or high HbG [0.628 (0.489-0.768); P<0.01]. Only age was independently associated with high-HbG status [10-year OR: 1.3 (1.1-1.5); P<0.0001]. CONCLUSION: Haemoglobin glycation may explain many of the discordant results between HbA1c and OGTT when used for dysglycaemia diagnosis.

RANTES/CCL5-induced pro-angiogenic effects depend on CCR1, CCR5 and glycosaminoglycans.

Atherosclerosis involves angiogenesis and inflammation with the ability of endothelial cells and monocytes to respond to chemokines. We addressed here by in vitro and in vivo approaches, the role of the chemokine Regulated on Activation, Normal T Cell Expressed and Secreted (RANTES)/CCL5 on angiogenesis through its receptors CCR1, CCR5, syndecan-1 (SDC-1), syndecan-4 (SDC-4) and CD-44. Our data demonstrate that RANTES/CCL5 is pro-angiogenic in a rat subcutaneous model. This RANTES/CCL5-activity may be related to the in vitro promotion of endothelial cell migration, spreading and neo-vessel formation. RANTES/CCL5-mediated angiogenesis depends at least partly on Vascular Endothelial Growth Factor (VEGF) secretion by endothelial cells, since this effect is decreased when endothelial cells are incubated with anti-VEGF receptor antibodies. RANTES/CCL5-induced chemotaxis is mediated by matrix metalloproteinase-9. We demonstrate that specific receptors of RANTES/CCL5 such as G protein-coupled receptors CCR1 and CCR5, and heparan sulfate proteoglycans, SDC-1, SDC-4 or CD-44, play a major role in RANTES/CCL5-induced angiogenic effects. By the use of two RANTES/CCL5 mutants, [E66A]-RANTES/CCL5 with impaired ability to oligomerize, and [44AANA47]-RANTES/CCL5 mutated in the main RANTES/CCL5-glycosaminoglycan (GAG) binding site, we demonstrate that chemokine oligomerization and binding to GAGs are essential in RANTES/CCL5-induced angiogenic effects. According to these results, new therapeutic strategies based on RANTES/CCL5 can be proposed for neo-angiogenesis after vascular injury. Mutants of RANTES/CCL5 may also represent an innovative approach to prevent the angiogenesis associated with the formation of atherosclerotic plaque.

What would be the outcome if the American Diabetes Association recommendations of 2010 had been followed in our practice in 1998-2006?

AIMS: In 2010, the American Diabetes Association has published recommendations on the population to be screened for dysglycaemia; the diagnostic criteria for intermediate hyperglycaemia and diabetes using oral glucose tolerance testing and HbA(1c); and the patients eligible for treatment with metformin. We aimed to evaluate the consequences of screening with oral glucose tolerance test or HbA(1c) in an at-risk population. METHODS: Among 1177 overweight or obese consecutive adults without known diabetes who were referred to our department for weight management, we selected 1157 individuals (83% female; 80% European) fulfilling the American Diabetes Association 2010 criteria for dysglycaemia screening. RESULTS: Mean age was 41.2 ± 13 years, BMI 37.0 ± 7.2 kg/m(2), fasting plasma glucose 4.9 ± 0.8 mmol/l and HbA(1c) (turbidimetric immunoassay) 5.7 ± 0.7% (39 mmol/mol). Based on oral glucose tolerance test and HbA(1c), respectively, 76 (6.6%) and 113 (9.8%) patients had diabetes, including 34 sharing both criteria; 307 (26.5%) and 478 (41.3%) had intermediate hyperglycaemia; and 130 (11.2%) and 255 (22.0%) would be treated with metformin. The sensitivity/specificity of HbA(1c) ≥ 6.5% (48 mmol/mol) for the diagnosis of diabetes according to the oral glucose tolerance test were 44.7/92.7%. Diabetes risk scores and UK Prospective Diabetes Study cardiovascular risk score were the highest in the 130 patients having both an abnormal oral glucose tolerance test and HbA(1c) ≥ 5.7%. CONCLUSIONS: In a population at risk for diabetes, the HbA(1c) strategy could lead to diagnosing more cases of dysglycaemia and to treating more patients with metformin than the oral glucose tolerance test strategy. The consistency of either diagnostic criteria was low. The patients with the highest a priori risk of diabetes and cardiovascular disease were those fulfilling both oral glucose tolerance test and HbA(1c) criteria.

Manganese superoxide dismutase dimorphism relationship with severity and prognosis in cardiogenic shock due to dilated cardiomyopathy.

The aim was to determine (a) Ala-16Val-SOD2 dimorphisms; (b) allelic frequency and phenotype of a common Pro-Leu polymorphism in GPx1, in a cohort of patients with a cardiogenic shock (CS) due to dilated cardiomyopathy without acute coronary syndrome. Consecutive patients with de novo CS that worsened a dilated (DCM) or ischemic (ICM) cardiomyopathy. Congenital heart disease, pacemaker and other shock aetiologies were excluded. To determine oxidative stress (OS), this study evaluated lipid peroxidation, protein oxidation and erythrocyte GPx, SOD and catalase activities. Ala16Val-SOD2 (dbSNP: rs4880) and Pro198Leu-GPx1 (dbSNP: rs1050450) polymorphisms were studied by allelic discrimination using fluorogenic probes and the 5'nuclease (TaqMan) assay. Twenty-four patients (with ICM (n = 8) or DCM (n = 16), age = 57.5 ± 10.7 years, LVEF = 25.3 ± 8.5%, NT-proBNP levels = 8540 ± 1703 ng/L) were included during a 15 month follow-up. OS parameters were significantly higher in patients than in controls. Distribution of MnSOD genotypes was 47% Val/Val-variant, 29.5% Ala/Val and 23.5% Ala/Ala-variants. Severity of CS was more important in patients with Val/Val-variant and can be put in parallel with NT-proBNP levels (Val/Val-variant: 11 310 ± 3875 ng/L vs Ala/Ala-variant: 6486 ± 1375 ng/L and Ala/Val-variant: 6004 ± 2228 ng/L; p < 0.05) and hemodynamic support duration (144.6 vs Ala/Val-variant: 108.8 h and Ala/Ala-variant: 52.5 h; p < 0.05) with a positive correlation (Spearman rho = 0.72, p < 0.05). Moreover, Val/Val-variant significantly influenced the mortality (Spearman rho = 0.67, p < 0.05), but not the morbidity (p = 0.3). Distribution of GPx genotypes was 64% Pro/Pro, 18% Pro/Leu and 18% Leu/Leu. GPx-variants influenced neither GPx activities nor cardiac events. In conclusion, CS was associated with markers of increased OS. GPx polymorphism did not influence the GPx activity. Only the Val-encoding MnSOD allele was significantly correlated with the severity and prognosis of CS.

Luteinizing hormone/human chorionic gonadotropin receptors in breast cancer.

Recent studies have suggested that human choriogonadotropin (hCG), in addition to its function in regulating steroidogenesis, may also play a role as a growth factor. Immunocytochemistry using two different monoclonal antibodies (LHR29 and LHR1055) raised against the human luteinizing hormone/human chorionic gonadotropin (LH/hCG) receptor allowed us to detect this receptor in breast cancer cell lines (T47D, MCF7, and ZR75) in individual cancer biopsies and in benign breast lesions. The receptor was also present in epithelial cells of normal human and sow breast. In the latter, its concentration increased after ovulation. The presence of LH/hCG receptor mRNA was confirmed by reverse transcription-PCR using primers extending over exons 2-4, 5-11, and 9-11. The proportion of LH/hCG-receptor positive cells and the intensity of the immunolabeling varied in individual biopsies, but there was no obvious correlation with the histological type of the cancer. These results are compatible with previous studies suggesting that during pregnancy, hCG is involved in the differentiation of breast glandular epithelium and that this hormone may play an inhibitory role in mammary carcinogenesis and in the growth of breast tumors.

Analysis of sera indeterminate by Ortho-HCV RIBA-2 by using three confirmatory assays for anti-hepatitis C virus antibody.

The diagnostic performances of three commercially available recombinant immunoblot assays (RIBAs) for anti-hepatitis C virus antibody were evaluated on 50 ORTHO-HCV RIBA-2 (RIBA-2)-indeterminate serum samples. Concordant interpretations were obtained with the three tests in 60% of the samples, with 56% positive, 2% indeterminate, and 2% negative results. Considering test performance in regard to the number of remaining indeterminate results, analyzing sera by RIBA-3, INNO-LIA HCV Ab III, and DECISCAN HCV reduced the number of samples reacting indeterminately to 40, 6, and 8%, respectively. The three serum samples classified as indeterminate in the INNO-LIA HCV Ab III as well as three of four serum samples interpreted as indeterminate in the DECISCAN HCV and 16 of 20 samples classified as indeterminate in the RIBA-3 were hepatitis C virus RNA positive by PCR. This study clearly shows the good performance of the three tests as confirmatory assays compared with that of the RIBA-2. However, according to the manufacturers' criteria of positivity, the INNO-LIA HCV Ab III and DECISCAN HCV appeared to be more suitable than the RIBA-3 for interpreting serum samples found indeterminate in the RIBA-2.

Enhanced detection of antibodies to hepatitis C virus by use of a third-generation recombinant immunoblot assay.

Fifty-seven sera with indeterminate results by the second generation RIBA (RIBA 2) for confirmation of hepatitis C virus (HCV) enzyme linked immunoassay (ELISA) reactivity were tested by the new third generation RIBA (RIBA 3). Thirty three (57.9%) displayed reactivity for at least one other band and were therefore classified as positive; two became negative and 22 (38%) remained indeterminate. The incidence of HCV viremia, as determined by the RNA polymerase chain reaction (PCR), was 75% for the latter sera. The data show that it is important to subject RIBA 3 indeterminate samples to PCR.