Exosome-Transmitted miR-25 Induced by H. pylori Promotes Vascular Endothelial Cell Injury by Targeting KLF2.

Background: Increasing evidence has shown that Helicobacter pylori is associated with coronary heart disease (CHD); however, the underlying mechanism remains unclear. Methods: The expression of miR-25 and mRNAs was measured using qRT-PCR. Protein levels were detected using western blotting and exosomes were assessed with an electron microscope. The target gene of miR-25 was identified using the luciferase report system. Results:H. pylori infection increased the expression of miR-25 in gastric epithelial cells and was associated with increased levels of exosome-transmitted miR-25 in human peripheral blood. Mechanistic investigation showed the Kruppel-like factor 2 (KLF2) was a direct target of exosome-transmitted miR-25 in vascular endothelial cells. In addition, the miR-25/KLF2 axis regulated the NF-κB signaling pathway, resulting in increased expression of interleukin 6 (IL6), monocyte chemoattractant protein-1 (MCP-1), vascular cell adhesion molecule-1 (VCAM-1), and intercellular adhesion molecule-1 (ICAM-1). Conclusion: Our findings suggest that the miR-25/KLF2 axis may be a potential therapeutic target for H. pylori-associated CHD. Furthermore, high levels of exosome-transmitted miR-25 in peripheral blood may pose a potential risk for CHD.

Helicobacter pylori CagA Protein Negatively Regulates Autophagy and Promotes Inflammatory Response via c-Met-PI3K/Akt-mTOR Signaling Pathway.

Cytotoxin-associated-gene A (CagA) of Helicobacter pylori (H. pylori) is a virulence factor that plays critical roles in H. pylori-induced gastric inflammation. In the present study, gastric biopsies were used for genotyping cagA and vacA genes, determining the autophagic activity, and the severity of gastric inflammation response. It was revealed that autophagy in gastric mucosal tissues infected with cagA+H. pylori strains was lower than the levels produced by cagA-H. pylori strains, accompanied with accumulation of SQSTM1 and decreased LAMP1 expression. In vitro, deletion mutant of cagA gene resulted in increased autophagic activity, and decreased expression of SQSTM1 and cytokines, whereas over-expression of CagA down-regulated the starvation-induced autophagy, and induced more production of the cytokines. Moreover, the production of the cytokines was increased by inhibition of autophagy, but decreased by enhancement of autophagy. Deletion of CagA decreased the ability to activate Akt kinase at Ser-473 site and increased autophagy. c-Met siRNA significantly affected CagA-mediated autophagy, and decreased the level of p-Akt, p-mTOR, and p-S6. Both c-Met siRNA and MK-2206 could reverse inflammatory response. H. pylori CagA protein negatively regulates autophagy and promotes the inflammation in H. pylori infection, which is regulated by c-Met-PI3K/Akt-mTOR signaling pathway activation.

Distribution of lung blood on modified bilateral Glenn shunt evaluated by Tc-99m-MAA lung perfusion scintigraphy: A retrospective study.

The aim of the present study was to determine the distribution of lung blood in a modified bilateral Glenn procedure designed in our institute with lung perfusion scintigraphy. Sixteen consecutive patients who underwent modified bilateral Glenn operation from 2011 to 2014 were enrolled in the study. The control group consisted of 7 patients who underwent bidirectional Glenn shunt. Radionuclide lung perfusion scintigraphy was performed using Tc-99m-macro aggregated albumin (MAA) in all patients. For the patients in modified bilateral Glenn group, the time at which the radioactivity accumulation peaked did not differ significantly between the right and left lung field (t = 0.608, P = 0.554). The incidence of perfusion abnormality in each lung lobe also did not differ significantly (P = 0.426 by Fisher exact test). The radioactive counts were higher in the right lung than in the left lung, but the difference was not statistically significant (t = 1.502, P = 0.157). Radioactive perfusion in the lower lung field was significantly greater than that in the upper field (t = 4.368, P < 0.001). Compared with that in the bidirectional Glenn group, the ratio of radioactivity in the right lung to that in left lung was significantly lower in the modified bilateral Glenn group (t = 3.686, P = 0.002). Lung perfusion scintigraphy confirmed the benefit of the modified bilateral Glenn shunt with regard to more balanced blood perfusion in both lungs.

Nicotine Induces Cardiomyocyte Hypertrophy Through TRPC3-Mediated Ca2+/NFAT Signalling Pathway.

BACKGROUND: Nicotine is thought to be an important risk factor for the development of cardiovascular diseases. However, the effects of nicotine on cardiomyocyte hypertrophy are poorly understood. The present study was designed to explore the role of nicotine in cardiomyocyte hypertrophy and its underlying mechanism. METHODS: We used primary cardiomyocytes isolated from Wistar rats to examine the effects of nicotine on intracellular Ca2+ mobilization and hypertrophy determined by immunofluorescence, quantitative polymerase chain reaction, and western blot analysis. A luciferase reporter assay was used to examine the activity of NFAT signalling. RESULTS: We found that nicotine caused cardiomyocyte hypertrophy, which was accompanied by increased intracellular Ca2+. Nicotine-enhanced intracellular Ca2+ concentration ([Ca2+]i) was significantly abolished by store-operated Ca2+ entry (SOCE) and TRPC inhibitors. Knockdown of TRPC3 significantly decreased nicotine-induced SOCE and hypertrophy. Moreover, calcineurin-nuclear factor of activated T cells (NFAT) is involved in TRPC3-mediated Ca2+ signalling and cardiomyocyte hypertrophy. Notably, upregulation of TRPC3 by nicotine requires TRPC3-mediated Ca2+ influx and calcineurin-NFAT signalling activation. CONCLUSIONS: Our findings demonstrate that the prohypertrophic effect of nicotine on cardiomyocytes is dependent on enhanced TRPC3 expression through a calcium-dependent regulatory loop, which could become a potential target for prevention and treatment of cardiac hypertrophy.

Electrospray ionization mass spectrometry study on dipeptide 4-chlorobutyl ester produced from refluxing of amino acid with phosphoryl chloride in tetrahydrofuran.

Phosphoryl chloride was able to promote the formation of peptide and the ringopening of tetrahydrofuran (THF) followed by a sequence of successive reactions by simply refluxing. ESI multistage tandem mass spectrometry was applied to trace the reaction and elucidate the product structures, dipeptide 4-chlorobutyl ester.