Changes in circulating sirtuin 1 after bariatric surgery

Background and aims: Obesity is associated with chronic inflammation and oxidative stress. Weight loss after bariatric surgery improves the inflammatory state and risk of cardiovascular disease. Improvement in metabolic dysfunction might be associated with changes in the activity of sirtuin 1 (SIRT1) and we aimed to investigate the effect of bariatric surgery on its circulating levels. Methods and results: This is a sub-study of a prospective cohort study, including 110 subjects with morbid obesity. The surgical procedure was either laparoscopic Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy (SG). Blood was sampled at inclusion and six and 12 months after surgery. SIRT1 was measured in EDTA plasma with an enzyme-linked immunosorbent assay. The mean age in the population was 43 years, 80% were women and mean body mass index (BMI) was 38.8 kg/m2. RYGB and SG were performed in 89 and 21 subjects, respectively. SIRT1 concentration was significantly reduced from baseline to six and 12 months after surgery, with mean values (SD) 156.8 (82.6), 119.5 (65.6) and 94.9 (45.6) ng/mL, respectively, (p 0.002, all), accompanied by significant reductions in C-reactive protein (CRP), BMI and triglycerides from inclusion (p < 0.001, all). Type of surgery did not differently modify SIRT1 levels (p Z 0.09). CRP and tri glycerides were both positively predictive of SIRT1 levels (p 0.001, both). Conclusion: SIRT1 concentration was significantly lower six and 12 months after bariatric surgery. CRP and triglycerides independently predicted SIRT1 levels, suggesting that reduction in SIRT1 levels might not intrinsically be related to weight reduction, but to improvement in metaflammation.publishedVersio

Circulating levels of IL-18 are significantly influenced by the IL-18 +183 A/G polymorphism in coronary artery disease patients with diabetes type 2 and the metabolic syndrome: an Observational Study

<p>Abstract</p> <p>Background</p> <p>Increased IL-18 serum levels have been associated with diabetes type 2, metabolic syndrome and the severity of atherosclerosis. The present study investigated the presence and influence of IL-18 genetic variants on gene- and protein expression in stable coronary artery disease (CAD) patients.</p> <p>Methods</p> <p>The +183 A/G (rs 5744292), -137 G/C (rs 187238) and -607 C/A (rs 1946518) polymorphisms were determined in 1001 patients with angiographically verified stable CAD, and in 204 healthy controls. IL-18 gene-expression was measured in circulating leukocytes in 240 randomly selected patients. Circulating IL-18 and IL-18 binding protein levels were measured immunologically in all patients.</p> <p>Results</p> <p>The +183 G-allele associated significantly with lower serum levels of IL-18 (<it>p </it>= 0.002, adjusted for age, glucose, body mass index and gender) and a 1.13- fold higher IL-18 gene-expression (<it>p </it>= 0.010). No influence was observed for the -137 G/C and -607 C/A polymorphisms. The IL-18 binding protein levels were not influenced by IL-18 genotypes. IL-18 levels were significantly higher in men as compared to women, and in patients with diabetes type 2 and metabolic syndrome compared to those without (<it>p </it>≤ 0.001, all). The reduction in IL-18 levels according to the +183 G-allele was 3-4 fold more pronounced in diabetes and metabolic syndrome as compared to unaffected patients.</p> <p>Finally, the +183 AA genotype was more frequent in patients with hypertension (<it>p </it>= 0.042, adjusted for age, body mass index and gender).</p> <p>Conclusion</p> <p>The reduction in serum IL-18 levels across increasing numbers of +183G-alleles was especially apparent in patient with diabetes type 2 and metabolic syndrome, suggesting a beneficial GG genotype in relation to cardiovascular outcome in these patients.</p> <p>Clinical Trial Registration Number</p> <p>ClinicalTrials.gov: <a href="http://www.clinicaltrials.gov/ct2/show/NCT00222261">NCT00222261</a></p

The influence of CYP 2C19*2 polymorphism on platelet function testing during single antiplatelet treatment with clopidogrel

<p>Abstract</p> <p>Background</p> <p>Different platelet function tests can be used to evaluate the degree of achieved platelet inhibition in patients treated with clopidogrel. The presence of CYP 2C19*2 polymorphism can reduce the formation of the active metabolite of clopidogrel, resulting in less platelet inhibition.</p> <p>Patients and Methods</p> <p>Patients with symptomatic coronary artery disease, all on chronic single aspirin treatment were randomized to continue on aspirin or change to clopidogrel. In 219 randomly selected clopidogrel treated patients, platelet reactivity was evaluated by VASP-PRI determination and by use of VerifyNow P2Y12-PRU. The CYP 2C19*2 G/A polymorphism was further determined.</p> <p>Results</p> <p>The total frequency of clopidogrel resistance was 29.0% by VASP-PRI and 31.6% by VerifyNow-PRU. The number of patients being hetero- and homozygous combined for the CYP 2C19*2 polymorphism (GA/AA) was 64 (29%). Platelet reactivity was significantly higher in patients with the polymorphism compared to wild-type patients (GG). VASP-PRI was 50.9% (SD19) in patients having the polymorphism compared to 38.3% (SD21) in patients with the GG genotype (p = 0.001). Correspondingly, the mean PRU was 165 (SD67) compared to 124 (SD69) (p < 0.001). The frequency of clopidogrel resistance in patients with the polymorphism was 32% compared to 16% in wild-type patients when defined by VASP-PRI (p = 0.006). When defined by PRU (VerifyNow), the corresponding frequencies were 53% and 22% (p < 0.001).</p> <p>Conclusions</p> <p>Clopidogrel treated patients with the CYP 2C19*2 polymorphism have significantly increased platelet reactivity compared to patients with the wild-type, evaluated with the VASP determination, and even more pronounced with the VerifyNow P2Y12 method.</p> <p>Trial Registration</p> <p>ClinicalTrials.gov: <a href="http://www.clinicaltrials.gov/ct2/show/NCT00222261">NCT00222261</a></p

Gender differences of polymorphisms in the TF and TFPI genes, as related to phenotypes in patients with coronary heart disease and type-2 diabetes

<p>Abstract</p> <p>Background</p> <p>Tissue factor (TF) and its inhibitor tissue factor pathway inhibitor (TFPI) are the main regulators of the initiation of the coagulation process, important in atherothrombosis. In this study we have investigated the frequency of six known TF and TFPI single nucleotide polymorphisms (SNPs) in CHD patients as compared to healthy individuals. These genotypes and the phenotypes (TF, TFPI free and total antigen) were evaluated with special reference to gender and diabetes in the CHD population.</p> <p>Methods</p> <p>Patients with angiographically verified CHD (n = 1001; 22% women, 20% diabetics), and 204 healthy controls (28% women), were included. The investigated SNPs were: TF -1812C/T and TF -603A/G in the 5'upstream region, TF 5466A/G in intron 2, TFPI -399C/T and TFPI -287T/C in the 5'upstream region and the TFPI -33T/C in intron 7.</p> <p>Results</p> <p>No significant differences in frequencies between the CHD population and the controls of any polymorphisms were observed. In the CHD population, the TF 5466 A/G SNP were significantly more frequent in women as compared to men (p < 0.001). The TF-1812C/T and the TF-603A/G SNPs were significantly more frequent in women without type-2 diabetes compared to those with diabetes (p < 0.018, both), and the heterozygous genotypes were associated with significantly lower TF plasma levels compared to the homozygous genotypes (p < 0.02, both).</p> <p>The TFPI-399C/T and the TFPI-33T/C SNPs were associated with lower and higher TFPI total antigen levels, respectively (p < 0.001, both).</p> <p>Conclusion</p> <p>Genetic variations in the TF and TFPI genes seem to be associated with gender and type-2 diabetes, partly affecting their respective phenotypes.</p

High-resolution visualization and assessment of basal and OXPHOS-induced mitophagy in H9c2 cardiomyoblasts

Mitochondria are susceptible to damage resulting from their activity as energy providers. Damaged mitochondria can cause harm to the cell and thus mitochondria are subjected to elaborate quality-control mechanisms including elimination via lysosomal degradation in a process termed mitophagy. Basal mitophagy is a house-keeping mechanism fine-tuning the number of mitochondria according to the metabolic state of the cell. However, the molecular mechanisms underlying basal mitophagy remain largely elusive. In this study, we visualized and assessed the level of mitophagy in H9c2 cardiomyoblasts at basal conditions and after OXPHOS induction by galactose adaptation. We used cells with a stable expression of a pH-sensitive fluorescent mitochondrial reporter and applied state-of-the-art imaging techniques and image analysis. Our data showed a significant increase in acidic mitochondria after galactose adaptation. Using a machine-learning approach we also demonstrated increased mitochondrial fragmentation by OXPHOS induction. Furthermore, super-resolution microscopy of live cells enabled capturing of mitochondrial fragments within lysosomes as well as dynamic transfer of mitochondrial contents to lysosomes. Applying correlative light and electron microscopy we revealed the ultrastructure of the acidic mitochondria confirming their proximity to the mitochondrial network, ER and lysosomes. Finally, exploiting siRNA knockdown strategy combined with flux perturbation with lysosomal inhibitors, we demonstrated the importance of both canonical as well as non-canonical autophagy mediators in lysosomal degradation of mitochondria after OXPHOS induction. Taken together, our high-resolution imaging approaches applied on H9c2 cells provide novel insights on mitophagy during physiologically relevant conditions. The implication of redundant underlying mechanisms highlights the fundamental importance of mitophagy

Tissue Factor Pathway Inhibitor, Hormone Replacement Therapy and risk of Venous Thromboembolism

SUMMARY Blood coagulation may lead to venous thromboembolism (VTE). Tissue factor pathway inhibitor (TFPI) is an important inhibitor of blood coagulation, however, the clinical significance or frequency of TFPI deficiency is yet not known. In the present study four known single nuclear polymorphisms (5 fUTR -287T ¨C, 5 fUTR -399C ¨T, intron 7 ¨33T-C, exon 9, 874G ¨A) of the TFPI gene has been investigated. Materials from two clinical trials (the EVTET and RET trials), including women previously suffering from VTE and healthy women, have been studied. All participants were randomized to different hormone replacement therapy (HRT) or placebo, i.e. high- and low dose estrogen or different formulas. A third group of healthy blood donors were also studied. All four TFPI polymorphisms were identified using Real Time Polymerase Chain Reaction, RT-PCR, and fluorescent hybridization probe melting curves. The results suggest that the 5 fUTR -287T ¨C and the intron 7 polymorphisms may protect against VTE, whereas 5 fUTR -399C ¨T may be associated with an increased risk of VTE. No clear association was seen between the exon 9 polymorphism and VTE, but this may due to the low frequency of the polymorphism. The study also suggests a considerable variance in the effect of the different TFPI polymorphisms on various estrogen formulas and doses, indicating that HRT should be individually adjusted