Do T2DM and Hyperglycaemia Affect the Expression Levels of the Regulating Enzymes of Cellular O-GlcNAcylation in Human Saphenous Vein Smooth Muscle Cells?

Protein O-GlcNAcylation, a dynamic and reversible glucose-dependent post-translational modification of serine and threonine residues on target proteins, has been proposed to promote vascular smooth muscle cell proliferation and migration events implicated in vein graft failure (VGF). Therefore, targeting the enzymes (glutamine fructose-6P amidotransferase (GFAT), O-GlcNAc transferase (OGT), and O-GlcNAcase (OGA)) that regulate cellular O-GlcNAcylation could offer therapeutic options to reduce neointimal hyperplasia and venous stenosis responsible for VGF. However, it is unclear how type 2 diabetes mellitus (T2DM) and hyperglycaemia affect the expression of these enzymes in human saphenous vein smooth muscle cells (HSVSMCs), a key cell type involved in the vascular dysfunction responsible for saphenous VGF. Therefore, our aim was to assess whether T2DM and hyperglycaemia affect GFAT, OGT, and OGA expression levels in HSVSMCs in vitro. Expression levels of GFAT, OGT, and OGA were determined in low-passage HSVSMCs from T2DM and non-T2DM patients, and in HSVSMCs treated for 48 h with hyperglycaemic (10 mM and 25 mM) glucose concentrations, by quantitative immunoblotting. Expression levels of OGT, OGA, and GFAT were not significantly different in HSVSMC lysates from T2DM patients versus non-T2DM controls. In addition, treatment with high glucose concentrations (10 mM and 25 mM) had no significant effect on the protein levels of these enzymes in HSVSMC lysates. From our findings, T2DM and hyperglycaemia do not significantly impact the expression levels of the O-GlcNAcylation-regulating enzymes OGT, OGA, and GFAT in HSVSMCs. This study provides a foundation for future studies to assess the role of O-GlcNAcylation on VGF in T2DM

Development of a human model for the study of effects of hypoxia, exercise, and sildenafil on cardiac and vascular function in chronic heart failure

Background: Pulmonary hypertension is associated with poor outcome in patients with chronic heart failure (CHF) and may be a therapeutic target. Our aims were to develop a noninvasive model for studying pulmonary vasoreactivity in CHF and characterize sildenafil's acute cardiovascular effects. Methods and Results: In a crossover study, 18 patients with CHF participated 4 times [sildenafil (2 × 20 mg)/or placebo (double-blind) while breathing air or 15% oxygen] at rest and during exercise. Oxygen saturation (SaO2) and systemic vascular resistance were recorded. Left and right ventricular (RV) function and transtricuspid systolic pressure gradient (RVTG) were measured echocardiographically. At rest, hypoxia caused SaO2 (P = 0.001) to fall and RVTG to rise (5 ± 4 mm Hg; P = 0.001). Sildenafil reduced SaO2 (−1 ± 2%; P = 0.043), systemic vascular resistance (−87 ± 156 dyn·s−1·cm−2; P = 0.034), and RVTG (−2 ± 5 mm Hg; P = 0.05). Exercise caused cardiac output (2.1 ± 1.8 L/min; P < 0.001) and RVTG (19 ± 11 mm Hg; P < 0.0001) to rise. The reduction in RVTG with sildenafil was not attenuated by hypoxia. The rise in RVTG with exercise was not substantially reduced by sildenafil. Conclusions: Sildenafil reduces SaO2 at rest while breathing air, this was not exacerbated by hypoxia, suggesting increased ventilation–perfusion mismatching due to pulmonary vasodilation in poorly ventilated lung regions. Sildenafil reduces RVTG at rest and prevents increases caused by hypoxia but not by exercise. This study shows the usefulness of this model to evaluate new therapeutics in pulmonary hypertension

The effect of atorvastatin (and subsequent metformin) on adipose tissue acylation-stimulatory-protein concentration and inflammatory biomarkers in overweight/obese women with polycystic ovary syndrome

Copyright © 2019 Sathyapalan, Hobkirk, Javed, Carroll, Coady, Pemberton, Smith, Cianflone and Atkin. Background: Atorvastatin has been shown to improve cardiovascular risk (CVR) indices in women with polycystic ovary syndrome (PCOS). Low-grade chronic inflammation of adipose tissue may link PCOS and adverse CVR. In pro-inflammatory states such as PCOS, spontaneous activation of the alternative pathway of complement results in increased generation of acylation stimulating protein (ASP) from adipocytes irrespective of body mass index. Methods: The objective of this study was to determine the effect of atorvastatin on markers of adipose tissue dysfunction and inflammation; acylation-stimulating-protein (ASP), interleukin-6 (IL-6), and monocyte-chemoattractant-protein-1 (MCP-1) in PCOS. This was a randomized, double-blind, placebo-controlled study where 40 medication-naive women with PCOS and biochemical hyperandrogenaemia were randomized to either atorvastatin 20 mg daily or placebo for 12 weeks. Following the 12 week randomization; both group of women with PCOS were subsequently started on metformin 1,500 mg daily for further 12 weeks to assess whether pre-treatment with atorvastatin potentiates the effects of metformin on markers of adipose tissue function We conducted a post-hoc review to detect plasma ASP and the pro-inflammatory cytokines IL6 and MCP-1 before and after 12 and 24 weeks of treatment. Results: There was significant reduction in ASP (156.7 ± 16.2 vs. 124.4 ± 14.8 ng/ml

Differential improvements in lipid profiles and Framingham recurrent risk score in patients with and without diabetes mellitus undergoing long-term cardiac rehabilitation.

OBJECTIVE: To determine whether lipid profiles and recurrent coronary heart disease (CHD) risk could be modified in patients with and without diabetes mellitus undergoing long-term cardiac rehabilitation (CR). DESIGN: Retrospective analysis of patient case records. SETTING: Community-based phase 4 CR program. PARTICIPANTS: Patients without diabetes (n=154; 89% men; mean ± SD age, 59.6 ± 8.5y; body mass index [BMI], 27.0 ± 3.5 kg/m²) and patients with diabetes (n=20; 81% men; mean age, 63.0 ± 8.7y; BMI, 28.7 ± 3.3 kg/m²) who completed 15 months of CR. INTERVENTIONS: Exercise testing and training, risk profiling, and risk-factor education. MAIN OUTCOME MEASURES: Cardiometabolic risk factors and 2- to 4-year Framingham recurrent CHD risk scores were assessed. RESULTS: At follow up, a significant main effect for time was evident for decreased body mass and waist circumference and improved low-density lipoprotein cholesterol (LDL-C) level and submaximal cardiorespiratory fitness (all P<.05), showing the benefits of CR in both groups. However, a significant group-by-time interaction effect was evident for high-density lipoprotein cholesterol (HDL-C) level and total cholesterol (TC)/HDL-C ratio (both P<.05). TC/HDL-C ratio improved (5.0 ± 1.5 to 4.4 ± 1.3) in patients without diabetes, but showed no improvement in patients with diabetes (4.8 ± 1.6 v 4.9 ± 1.6). CONCLUSIONS: We showed that numerous anthropometric, submaximal fitness, and cardiometabolic risk variables (especially LDL-C level) improved significantly after long-term CR. However, some aspects of cardiometabolic risk (measures incorporating TC and HDL-C) improved significantly in only the nondiabetic group

Anthropometric and Metabolic Responses in FTO rs9939609 Gene Polymorphism after a Multidisciplinary Lifestyle Intervention in Overweight and Obese Adolescents

Few studies show the potential changing effect of fat-mass and obesity-associated (FTO) rs9939609 gene on cardiometabolic risk after a lifestyle intervention. This study aims to evaluate whether overweight and obese adolescents, carriers of the risk genotypes for obesity of the FTO rs9939609 gene polymorphism, have differentanthropometric and biochemical responses to an interdisciplinary intervention program. The quasi-experimental study involved 34 adolescents aged 10 to 15 years. Schoolchildren with AA/AT genotype decreased glucose, total cholesterol, low-densitylipoprotein cholesterol, and increased high-density lipoprotein cholesterol. However, there were no differences between the genotypes, suggesting that the “A” allele did not modify the subject’s response to the intervention program

Metabolic risk is associated with sociodemographic characteristics in adolescents from both rural and urban regions from southern Brazil

Background: The prevalence of several cardiovascular metabolic disorders are increasingly cause for concern in adolescents worldwide. Given the complex interrelations between metabolic risk (MR) and sociodemographic variables, the present study aims to examine the association between the presence of MR with sociodemographic characteristics (sex, skin color, residential area, and parental socioeconomic status) in adolescents from Southern Brazil. Methods: Cross-sectional study conducted with 1,152 adolescents (507 males) aged between 12 and 17 years. MR was assessed using a continuous score (cMetS; sum of Z-scores of the following variables: waist circumference, systolic blood pressure (SBP), glucose, high-density lipoprotein cholesterol [HDL-C, inverse], triglycerides [TG], and estimated cardiorespiratory fitness [CRF, inverse]). Poisson regression was used to examine associations between sociodemographic variables with the dichotomized cMetS and separate metabolic variables. The results were expressed with prevalence ratios (PR) and 95% confidence intervals (CI). Results: The presence of MR (evaluated by the cMetS) was observed in 8.7% of adolescents. Higher MR was less prevalent among non-white adolescents (PR: 0.96; 95% CI: 0.93; 0.99). Adolescents living in rural areas had a lower prevalence of the following metabolic variables; low HDL-C (PR: 0.95; 95% CI: 0.94; 0.97), elevated TG (PR: 0.95; 95% CI: 0.92; 0.99), elevated glucose (PR: 0.96; 95% CI: 0.95; 0.98), and low CRF levels (PR: 0.88; 95% CI: 0.85; 0.92). Whereas, SBP was higher in those living in rural areas (PR: 1.11; 95% CI: 1.05; 1.17). In girls, there was a higher prevalence of raised TG (PR: 1.06; 95% CI: 1.02; 1.10) and lower levels of CRF (PR: 1.20; 95% CI: 1.16; 1.24), but a lower prevalence of elevated glucose (PR: 0.97; 95% CI: 0.97; 0.99). Conclusion: Higher MR prevalence was lower in those self-reporting non-white skin color and selected MR factors were less prevalent in those living in rural areas. The identification of groups at higher MR is important for early prevention and monitoring strategies for both Type 2 diabetes and later cardiovascular disease. Future studies should be conducted to assess the socio-cultural aspects of the relationships between MR and socio-cultural and lifestyle variables

Proinflammatory Activation of Osteoclasts Due to High Prolactin Level

High concentrations of prolactin (PRL) during the lactation period have an essential role in milk production by mammary glands stimulation. PRL may have an impact on calcium regulation and bone mineral density. We investigated if the PRL concentration during the lactation period could influence osteoclast (OC) activation and bone mineral density (BMD). In vivo, the Calcium Detection Assay, and ELISA were used to detect serum calcium, PRL, and inflammatory cytokines, respectively. BMD was evaluated by µ-CT in six months old female mice during lactation. The osteoclast (OC) activity was detected by Tartrate-resistant acid phosphatase (TRAP), Immunohistochemistry (IHC), and hematoxylin and eosin (H&E). In vitro, osteoclast differentiation, resorption and their activity markers TRAP, Matrix metallopeptidase 9 (MMP-9), Cathepsin K (CTSK), C-reactive protein (CRP), Receptor activator of nuclear factor kappa-Β (RANK) and inflammatory cytokines were measured in osteoclasts stimulated with recombinant prolactin protein (rPRL) or with an anti-prolactin blocker. We found that serum calcium, PRL, and inflammatory markers were increased. BMD was significantly reduced in lactating mice; TRAP activity was increased and tubercular was reduced in lactating mice compared to normal mice. In vitro, the osteoclast number, resorption, and activation markers TRAP, MMP-9, CTSK, CRP, and RANK were significantly increased after treatment with rPRL protein, but not in osteoclasts treated with anti-prolactin receptor antibody and rPRL. The gene expression of TNF-α, IL-6, and Monocyte chemoattractant protein-1 (MCP-1) but not IL-1b were significantly increased in osteoclasts with PRL treatment compared to the untreated osteoclasts. Taken together, the high level of PRL could activate osteoclasts and proinflammatory cytokines expression which reduce BMD in the lactation period

The clinical and lifestyle determinants of serum HDL-c, apolipoprotein A-1, paraoxonase-1 activity and oxidised LDL in healthy, medication naive middle-aged adults.

Introduction: HDL cholesterol may underestimate the anti-oxidative potential of HDL. HDL anti-oxidative potential is mediated by PON-1, which metabolises lipid peroxides and impacts on oxidised LDL (ox-LDL) concentrations. We sought to investigate the determinants of HDL-c, apo A-I and PON-1 activity and to ascertain whether HDL-c, apo A-I, PON-1 activity could explain the variance of ox-LDL concentrations in a sub-group of high PON-1 activity (n=22) >230 or low (n=22) <63 nmol/min/ml participants. Methods: 221 (72% male) participants were assessed during health assessments at Nuffield Health Medical Centre in Manchester. Participants avoided vigorous physical activity and alcohol 24 hours prior to assessment. Lifestyle factors including smoking status, alcohol intake and physical activity and cardio-respiratory fitness were assesssed. Participants with CVD or T2D were excluded. Fasting blood was taken to measure HDL-c, PON-1 activity, apo AI and ox-LDL and other blood variables. Correlations and regression analysis assessed inter-relationships and determinants of HDL-c, apo A-1, PON-1 activity and ox-LDL. Regression models included age, sex, waist, TG, alcohol, physical activity, fitness, hs-CRP and QRISK. Results: The correlation between PON-1 activity and HDL-c (r=0.12), apo A-I (r=0.11) were non-significant. Waist circumference, TG, alcohol intake, sex and fitness were predictors of HDL-c, accounting for 40.3% of the variance. Waist circumference, TG and alcohol predicted apo A-I concentrations, accounting for 13.1% of the variance. None of the variables measured predicted PON-1 activity. Ox-LDL was not significantly correlated with HDL-c (r=0-.19) apo A-I (r=-0.20) or PON-1 activity (r=0.09) but was to TG (r=0.69, p<0.001). Furthermore, TG (52%), hs-CRP (7.4%) and age (6.6%) accounted for 66% of the variance in ox-LDL. Discussion: PON-1 activity did not correlate with any clinical or lifestyle variables. Concentrations of ox-LDL were strongly related to TG concentrations. Lifestyle factors that regulate TG metabolism are an important therapy to decrease highly atherogenic ox-LDL particles