Effect of bariatric surgery on atherogenicity and insulin resistance in patients with obesity class II: a prospective study

OBJECTIVE

Enormous efforts have been made to evaluate reliable, simple and practical indicators for predicting patients at risk of progression of cardiovascular disease events, whereby bariatric surgery has remained understudied. Thus, we performed this study to assess the effect of bariatric surgery procedures on atherogenicity and insulin resistance indicators.

DESIGN

Cohort study.

SETTING, PARTICIPANTS AND OUTCOME MEASURES

Four hundred and forty-three class II obese (severely obese) patients who underwent sleeve gastrectomy, Roux-en-Y gastric bypass, or one anastomosis gastric bypass were followed up for 12 months after surgery. Atherosclerosis-related indicators were evaluated at baseline, as well as 6 and 12 months after surgery.

RESULTS

Atherogenic index of plasma, lipoprotein combine index, atherogenic coefficient, cholesterol index, Castelli's risk indices I and II, and triglyceride to high-density lipoprotein-cholesterol ratio (p<0.01) improved after 12 months. Additionally, bariatric surgery yielded a significantly reduced triglyceride glucose index. There was no significant difference between procedures in terms of indicators. The Spearman correlation test showed a significant inverse correlation between weight plus fat mass and atherosclerosis-related indicators as well as a positive correlation between percentage of excess weight loss and these indicators.

CONCLUSIONS

This study demonstrated three bariatric surgery procedures' ability to improve atherogenicity and insulin resistance in patients with obesity class II. The anti-atherogenicity effects can be partly assigned to the reduction of body weight and adipose tissue. Nevertheless, further studies with larger sample sizes and longer follow-ups are required to confirm our results.

COVID 19 disease independently predicted endothelial dysfunction measured by flow-mediated dilatation

The systemic effects of COVID-19 disease are still largely uncertain and needs to be scrutinized with further trials. Endothelial dysfunction (ED) is responsible for the majority of adverse cardiovascular events. Flow-mediated dilation (FMD) is easily obtainable method to assess ED accurately. It is aimed to evaluate ED by measuring FMD following COVID-19 disease. Patients diagnosed with COVID-19 disease were recruited to the hospital two month after the discharge. Sex and age-matched healthy subjects were determined as the control group. Blood samples and FMD measurements were obtained from each participant. All subjects were divided into two groups according to the presence of ED determined by FMD measurements. These two groups were compared in terms of demographic features and the presence of recovered COVID-19 disease. A total of 92 subjects consisting of 59 without ED and 33 with ED were included in the study. ED (+) group was older (p = 0.015) and more likely to have hypertension (p = 0.044) and COVID-19 rate was higher in ED (+) group (p = 0.009). While neutrophil count (p = 0.047) and CRP (p = 0.036) were higher, eGFR (p = 0.044) was lower in ED (+) group. In the backward multivariable regression analysis, COVID-19 disease [OR = 3.611, 95% CI 1.069-12.198, p = 0.039] and BMI [OR = 1.122, 95% CI 1.023-1.231, p = 0.015] were independent predictors of ED. COVID-19 disease may cause ED which is the major underlying factor of cardiovascular diseases. Furthermore, COVID-19 disease may deteriorate the existing cardiovascular disease course. Detecting ED in the early phase or preventing by new treatment modalities may improve short and long-term outcome.

An Injectable Nanocomposite Hydrogel for Potential Application of Vascularization and Tissue Repair

In this contribution, an injectable hydrogel was developed with chitosan, gelatin, β-glycerphosphate and Arg-Gly-Asp (RGD) peptide: this hydrogel is liquid in room temperature and rapidly gels at 37 °C; RGD peptide promises better growth microenvironment for various cells, especially endothelial cells (EC), smooth muscle cells (SMC) and mesenchymal stem cells (MSC). Both stromal cell-derived factor-1 (SDF-1) nanoparticle and vascular endothelial growth factor (VEGF) nanoparticles were loaded in the injectable hydrogel to simulate the natural nanoparticles in the extracellular matrix (ECM) to promote angiogenesis. In vitro EC/SMC and MSC/SMC co-culture experiment indicated that the nanocomposite hydrogel accelerated constructing embryonic form of blood vessels, and chick embryo chorioallantoic membrane model demonstrated its ability of improving cells migration and blood vessel regeneration. We injected this nanocomposite hydrogel into rat myocardial infarction (MI) model and the results indicated that the rats heart function recovered better compared control group. We hope this injectable nanocomposite hydrogel may possess wider application in tissue engineering.

Atherogenic Index of Plasma (AIP) a Tool to Assess Changes in Cardiovascular Disease Risk Post Laparoscopic Sleeve Gastrectomy

Predictive indices like the atherogenic index of plasma (AIP) have been developed to estimate the risk of cardiovascular disease (CVD). Metabolic surgery is the most effective treatment for a rapid improvement of morbid obesity and its comorbidities such as type 2 diabetes (T2D) and CVD. A decreased reoccurrence of CVD after metabolic surgery has been reported by several studies. However, studies utilizing predictive indices for CVD risk in CVD-free morbid-obese patients who undertook laparoscopic sleeve gastrectomy (LSG) are lacking. Here, we use AIP as a tool to evaluate the improvement in CVD risk post-LSG in morbid-obese people who had no history of CVD. Method. We compared baseline, 6- and 12-month post-LSG score of AIP, vascular age, circulating biochemical markers related to CVD in two groups of BMI and age-matched morbid-obese participants with and without T2D. Results. At baseline, people with T2D had significantly higher AIP both, with morbid obesity (0.23 ± 0.06, p < 0.001) and normal weight (0.022 ± 0.05, p < 0.001) compared to their BMI-matched without T2D group. People with morbid obesity had low AIP (-0.083 ± 0.06). Vascular age was significantly higher in people with morbid obesity and T2D (65.8 ± 3.7year, p < 0.0001) compared to morbid obesity (37.9 ± 2.6 year). After one year, AIP was significantly reduced compared to baseline score in people with morbid obesity with/without T2D, respectively (-0.135 ± 0.07, p = 0.003; and -0.36 ± 0.04, p = 0.0002). Conclusion. Our data illuminates AIP as a reliable predictive index for CVD risk in morbid-obese people who had no history of CVD. Moreover, AIP accurately distinguishes between morbid obesity with T2D and morbid obesity and showed a rapid and significant reduction in CVD risk after LSG in people who had no history of CVD. This is a ClinicalTrials.gov registered trial (Reference NCT03038373).

Evaluation of the elastic Young's modulus and cytotoxicity variations in fibroblasts exposed to carbon-based nanomaterials

Background

The conventional approaches to assess the potential cytotoxic effects of nanomaterials (NMs) mainly rely on in vitro biochemical assays. These assays are strongly dependent on the properties of the nanomaterials, for example; specific surface area (SSA), size, surface defects, and surface charge, and the host response. The NMs properties can also interfere with the reagents of the biochemical and optical assays leading to skewed interpretations and ambiguous results related to the NMs toxicity. Here, we proposed a structured approach for cytotoxicity assessment complemented with cells’ mechanical responses represented as the variations of elastic Young’s modulus in conjunction with conventional biochemical tests. Monitoring the mechanical properties responses at various times allowed understanding the effects of NMs to the filamentous actin cytoskeleton. The elastic Young’s modulus was estimated from the force volume maps using an atomic force microscope (AFM).

Results

Our results show a significant decrease on Young’s modulus, ~ 20%, in cells exposed to low concentrations of graphene flakes (GF), ~ 10% decrease for cells exposed to low concentrations of multiwalled carbon nanotubes (MWCNTs) than the control cells. These considerable changes were directly correlated to the disruption of the cytoskeleton actin fibers. The length of the actin fibers in cells exposed to GF was 50% shorter than the fibers of the cells exposed to MWCNT. Applying both conventional biochemical approach and cells mechanics, we were able to detect differences in the actin networks induced by MWCNT inside the cells and GF outside the cell’s membrane. These results contrast with the conventional live/dead assay where we obtained viabilities greater than 80% after 24 h; while the elasticity dramatically decreased suggesting a fast-metabolic stress generation.

Conclusions

We confirmed the production of radical oxygen species (ROS) on cells exposed to CBNs, which is related to the disruption of the cytoskeleton. Altogether, the changes in mechanical properties and the length of F-actin fibers confirmed that disruption of the F-actin cytoskeleton is a major consequence of cellular toxicity. We evidenced the importance of not just nanomaterials properties but also the effect of the location to assess the cytotoxic effects of nanomaterials.

Electronic supplementary material

The online version of this article (10.1186/s12951-019-0460-8) contains supplementary material, which is available to authorized users.

Design and Applications of Cell-Selective Surfaces and Interfaces

Tissue regeneration involves versatile types of cells. The accumulation and disorganized behaviors of undesired cells impair the natural healing process, leading to uncontrolled immune response, restenosis, and/or fibrosis. Cell-selective surfaces and interfaces can have specific and positive effects on desired types of cells, allowing tissue regeneration with restored structures and functions. This review outlines the importance of surfaces and interfaces of biomaterials with cell-selective properties. The chemical and biological cues including peptides, antibodies, and other molecules, physical cues such as topography and elasticity, and physiological cues referring mainly to interactions between cells-cells and cell-chemokines or cytokines are effective modulators for achieving cell selectivity upon being applied into the design of biomaterials. Cell-selective biomaterials have also shown practical significance in tissue regeneration, in particular for endothelialization, nerve regeneration, capture of stem cells, and regeneration of tissues of multiple structures and functions.

The effects of corrective surgery on endothelial biomarkers and anthropometric data in children with congenital heart disease

Objective To investigate the influence of surgical correction on biomarkers of endothelial dysfunction in children with congenital heart disease and to evaluate anthropometric data. Methods Children with pulmonary hypertension (PH) or Tetralogy of Fallot (TOF) who were scheduled for corrective surgery were enrolled in this prospective study. Age-matched healthy children were included as controls. Demographic, haemodynamic and cardiac ultrasonography data were collected. Blood samples were taken pre-surgery, 24-48 hours post-surgery and again 3-6 months later. Several biomarkers (protein C, soluble platelet selectin [CD62P], soluble endothelium selectin [CD62E], soluble leukocyte selectin [CD62L], plasma von Willebrand Factor [vWF] atrial natriuretic peptide [ANP], brain natriuretic peptide[(BNP] and insulin-like growth factor-1 [IGF-1]) were measured. Results Sixty-three children (32 with PH, 15 with TOF, and 16 controls) were enrolled. No significant differences between the PH and TOF groups were observed in the expression of biomarkers pre- and post-surgery. IGF-1 levels were closely related to anthropometric data, particularly those children with PH. Expression of IGF-1 and weight/height normalized after corrective surgery. Conclusions No significant endothelial dysfunction was observed in children with PH or TOF before or after corrective surgery. Significant retardation of growth, particularly weight, was found before surgery and may be related to IGF-1 suppression.

Left atrial endocardial dysfunction and platelet activation in patients with atrial fibrillation and mitral stenosis

OBJECTIVE

This study demonstrated left atrial endocardial dysfunction and platelet activation in patients with atrial fibrillation and mitral stenosis.

METHODS

Study included 80 patients with mitral stenosis and atrial fibrillation (40 each with and without left atrial thrombosis), 15 healthy volunteers, and 10 left atrial appendage (LAA) specimens from donor hearts. Blood samples were collected through peripheral vein and left atrium, with peripheral blood samples of volunteers as controls. LAA specimens were collected during operations. LAA expressions of von Willebrand factor (vWF) and P-selectin were determined immunohistochemically; plasma concentrations were measured by enzyme-linked immunosorbent assay. LAA expressions of vWF and P-selectin genes in were quantitated with real-time fluorescent quantitative polymerase chain reaction.

RESULTS

The difference in vWF and P-selectin plasma levels between left atrial and peripheral venous blood was not significant; however, peripheral plasma levels of vWF and P-selectin were significantly higher in those with thrombosis than without thrombosis, which in turn were higher than in healthy subjects. Both vWF and P-selectin proteins were stained in both left atrial endocardium and cardiomyocytes. The normalized vWF gene expression relative to control was 3.04 in patients with thrombosis and 2.16 in those without thrombosis (P<.01). The difference in P-selectin gene expressions among the groups was not significant.

CONCLUSIONS

No differences were observed in plasma levels of vWF and P-selectin between left atrial and peripheral venous blood. Over expression of vWF gene in LAA may contribute to increased plasma vWF levels. P-selectin and vWF together may play a role in thrombosis.

Multiwall carbon nano-onions induce DNA damage and apoptosis in human umbilical vein endothelial cells

Growing evidence has indicated the potential adverse effects on cardiovascular system of some nanomaterials, including fullerenes. In this study, we have evaluated the biological effects of multiwall carbon nano-onions (MWCNOs) (average size of 31.2 nm, ζ potential of 1.6 mV) on human umbilical vein endothelial cells (HUVECs). It was found that MWCNOs exhibited a dose-dependent inhibitory effect on cell growth; EC50 was 44.12 μg/mL. Thus, three concentrations were chosen (0.2, 1, and 5 μg/mL) for further experiments. Flow cytometry analysis revealed that 1 and 5 μg/mL MWCNOs could induce apoptosis in HUVECs, the apoptotic rates were 12% and 24% at 24 h after exposure. On the other hand, MWCNOs did not affect the cell cycle distribution during 24 h period. Using γH2AX foci formation as an indicator for DNA damage, it was shown that 5 μg/mL MWCNOs can induce γH2AX foci formation in HUVECs at 6, 12, and 24 h after treatment, whereas 0.2 μg/mL MWCNOs induced γH2AX foci formation only at 6 h after treatment. In addition, all three concentrations of MWCNOs induced the generation of reactive oxygen species (ROS), and inhibition of ROS generation can partially decrease the γH2AX foci formation induced by MWCNOs. Taken together, these data first suggested that MWCNOs can induce DNA damage and apoptosis in HUVECs, and that ROS might be involved in this process.

Myeloperoxidase is an early biomarker of inflammation and cardiovascular risk in prepubertal obese children

OBJECTIVE

Obesity is associated with a state of chronic low-grade inflammation. Myeloperoxidase (MPO) plays an important role in the initiation and progression of acute and chronic inflammatory diseases, such as cardiovascular disease (CVD). The objectives of the current study were to evaluate plasma MPO levels in prepubertal obese children and to determine whether MPO could be an early biomarker of inflammation and CVD risk.

RESEARCH DESIGN AND METHODS

In a prospective multicenter case-control study paired by age and sex of 446 Caucasian prepubertal children ages 6-12 years, 223 normal-weight and 223 obese children were recruited. Blood pressure, waist circumference, weight, and height were measured. In addition to MPO, glucose, insulin, metabolic lipid parameters, oxidized low-density lipoproteins, adiponectin, leptin, resistin, C-reactive protein (CRP), interleukin 6, tumor necrosis factor α, matrix metalloproteinase-9 (MMP-9), and plasminogen activator inhibitor 1 were determined.

RESULTS

We found that MPO was elevated in prepubertal obese children and that this enzyme was associated with such proinflammatory and cardiovascular risk biomarkers as CRP, MMP-9, and resistin. Insulin resistance calculated by the homeostatic assessment model was the best predictor of MPO.

CONCLUSIONS

MPO is an early biomarker of inflammation associated with CVD risk in obese children at the prepubertal age.

Green tea extract reverses endothelial dysfunction and reduces atherosclerosis progression in homozygous knockout low-density lipoprotein receptor mice

The aim of this study was to evaluate the effects of green tea extract (GTE) administration on vascular reactivity and atherosclerosis progression in low-density lipoprotein receptor knockout mice. We hypothesized that GTE intake may ameliorate atherosclerosis by improving endothelial dysfunction. Animals (n = 12 per group) were fed a hypercholesterolemic diet and received either water or GTE at a dose of 50, 100, or 300 mg/kg once a day by gavage (100 μL/10 g weight). After 4 weeks, atherosclerosis extension and vascular reactivity were evaluated in the aorta, and the levels of lipids, monocyte chemotactic protein-1 (MCP-1), and tumor necrosis factor α were measured in the plasma. Administration of GTE at a dose of 50 mg/kg significantly decreased the area of atherosclerotic lesions by 35%, improved the vascular reactivity in the isolated thoracic aorta, and lowered the plasma levels of both MCP-1 and triglycerides. Delivery of 100 mg/kg of GTE only promoted vasocontraction and vasorelaxation (P < .05), whereas a dose of 300 mg/kg was ineffective. Maximum contraction and relaxation negatively correlated with the lesion area (r = -0.755 and -0.767, respectively), whereas the plasma levels of MCP-1 and triglycerides positively correlated with plaque size (r = 0.549 and 0.421, respectively). In summary, our results supported the hypothesis that administration of GTE at low doses may contribute to a decrease in atherosclerosis progression by reversing endothelial dysfunction.

Vascularization is the key challenge in tissue engineering

The main limitation in engineering in vitro tissues is the lack of a sufficient blood vessel system - the vascularization. In vivo almost all tissues are supplied by these endothelial cell coated tubular networks. Current strategies to create vascularized tissues are discussed in this review. The first strategy is based on the endothelial cells and their ability to form new vessels known as neoangiogenesis. Herein prevascularization techniques are compared to approaches in which biomolecules, such as growth factors, cytokines, peptides and proteins as well as cells are applied to generate new vessels. The second strategy is focused on scaffold-based techniques. Naturally-derived scaffolds, which contain vessels, are distinguished from synthetically manufactured matrices. Advantages and pitfalls of the approaches to create vascularized tissues in vitro are outlined and feasible future strategies are discussed.