Background Epidemiological studies have suggested an association between Helicobacter pylori ( H pylori ) infection and atherosclerosis through undefined mechanisms. Endothelial dysfunction is critical to the development of atherosclerosis and related cardiovascular diseases. The present study was designed to test the hypothesis that H pylori infection impaires endothelial function through exosome‐mediated mechanisms. Methods and Results Young male and female patients (18‐35 years old) with and without H pylori infection were recruited to minimize the chance of potential risk factors for endothelial dysfunction for the study. Endothelium‐dependent flow‐mediated vasodilatation of the brachial artery was evaluated in the patients and control subjects. Mouse infection models with CagA + H pylori from a gastric ulcer patient were created to determine if H pylori infection‐induced endothelial dysfunction could be reproduced in animal models. H pylori infection significantly decreased endothelium‐dependent flow‐mediated vasodilatation in young patients and significantly attenuated acetylcholine‐induced endothelium‐dependent aortic relaxation without change in nitroglycerin‐induced endothelium‐independent vascular relaxation in mice. H pylori eradication significantly improved endothelium‐dependent vasodilation in both patients and mice with H pylori infection. Exosomes from conditioned media of human gastric epithelial cells cultured with CagA + H pylori or serum exosomes from patients and mice with H pylori infection significantly decreased endothelial functions with decreased migration, tube formation, and proliferation in vitro. Inhibition of exosome secretion with GW 4869 effectively preserved endothelial function in mice with H pylori infection. Conclusions H pylori infection impaired endothelial function in patients and mice through exosome‐medicated mechanisms. The findings indicated that H pylori infection might be a novel risk factor for cardiovascular diseases.
BaCKgRoUND aND aIMS: Hepatocellular carcinoma (HCC) is associated with high malignancy rates. Recently, a known deacetylase silent information regulator 1 (SIRT1) was discovered in HCC, and its presence is positively correlated with malignancy and metastasis. N 6-methyladenosine (m 6 A) is the most prominent modification, but the exact mechanisms on how SIRT1 regulates m 6 A modification to induce hepatocarcinogenesis remain unclear. appRoaCH aND ReSUltS: Here we demonstrate that SIRT1 exerts an oncogenic role by down-regulating fat mass and obesity-associated protein (FTO), which is an m 6 A demethylase. A crucial component of small ubiquitin-related modifiers (SUMOs) E3 ligase, RANBP2, is activated by SIRT1, and it is indispensable for FTO SUMOylation at Lysine (K)-216 site that promotes FTO degradation. Moreover, Guanine nucleotide-binding protein G (o) subunit alpha (GNAO1) is identified as m 6 A downstream targets of FTO and tumor suppressor in HCC, and depletion of FTO by SIRT1 improves m 6 A + GNAO1 and down-regulates its mRNA expression. CoNClUSIoNS: We demonstrate an important mechanism whereby SIRT1 destabilizes FTO, steering the m 6 A + of downstream molecules and subsequent mRNA expression in HCC tumorigenesis. Our findings uncover a target of SIRT1 for therapeutic agents to treat HCC.
Aim: Present study aimed to elucidate the suppression of serum lipids by gamma-and delta-tocotrienol ( T3).Methods: The lipid-lowering effects of T3 were investigated using HepG2 liver cell line, hypercholesterolemic mice and borderline-high cholesterol patients. Results:In-vitro results demonstrated two modes of action. First, T3 suppressed the upstream regulators of lipid homeostasis genes (DGAT2, APOB100, SREBP1/2 and HMGCR) leading to the suppression of triglycerides, cholesterol and VLDL biosyntheses. Second, T3 enhanced LDL efflux through induction of LDL receptor (LDLr) expression. Treatment of LDLr-deficient mice with 1 mg/day (50 mg/kg/day) T3 for one-month showed 28%, 19% reduction in cholesterol and triglyceride levels respectively, whereas HDL level was unaltered. The lipid-lowering effects were not affected by alpha-tocopherol ( TP). In a placebo-controlled human trial using 120 mg/day T3, only serum triglycerides were lowered by 28% followed by concomitant reduction in the triglyceriderich VLDL and chylomicrons. In contrast, total cholesterol, LDL and HDL remained unchanged in treated and placebo groups. The discrepancies between in-vitro, in-vivo and human studies may be attributed to the differential rates of post-absorptive T3 degradation and LDL metabolism. Conclusion: Reduction in triglycerides synthesis and transport may be the primary benefit caused by ingesting T3 in human.
Background and aims-Atherosclerosis is an important contributing factor to cardiovascular mortality. The role of Helicobacter pylori (H. pylori) infection in atherosclerosis is inconsistent and sometimes controversial. The present study aimed to determine if H. pylori infection is associated with carotid atherosclerosis. Methods-17,613 males and females with both carotid ultrasonic examination and 13 C-urea breath test for H. pylori infection were screened by a major Chinese university hospital from March 2012 to March 2017 for the study. Baseline demographics, cardiac risk factors, and laboratory studies were obtained. After exclusion for pre-specified conditions, 12,836 individuals were included in the analysis, including 8157 men (63.5%) and 4679 women (36.5%). Analysis was also made for 5-year follow-up data of 1216 subjects (869 males and 347 females) with and without H. pylori infection for development and progression of carotid atherosclerosis.
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