Induction of microRNA-199 by Nitric Oxide in Endothelial Cells Is Required for Nitrovasodilator Resistance via Targeting of Prostaglandin I2 Synthase.

BACKGROUND: Nitrates are widely used to treat coronary artery disease, but their therapeutic value is compromised by nitrate tolerance, because of the dysfunction of prostaglandin I2 synthase (PTGIS). MicroRNAs repress target gene expression and are recognized as important epigenetic regulators of endothelial function. The aim of this study was to determine whether nitrates induce nitrovasodilator resistance via microRNA-dependent repression of PTGIS gene expression. METHODS: Nitrovasodilator resistance was induced by nitroglycerin (100 mg·kg-1·d-1, 3 days) infusion in Apoe-/- mice. The responses of aortic arteries to nitric oxide donors were assessed in an organ chamber. The expression levels of microRNA-199 (miR-199)a/b were assayed by quantitative reverse transcription polymerase chain reaction or fluorescent in situ hybridization. RESULTS: In cultured human umbilical vein endothelial cells, nitric oxide donors induced miR-199a/b endogenous expression and downregulated PTGIS gene expression, both of which were reversed by 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide potassium salt or silence of serum response factor. Evidence from computational and luciferase reporter gene analyses indicates that the seed sequence of 976 to 982 in the 3'-untranslated region of PTGIS mRNA is a target of miR-199a/b. Gain functions of miR-199a/b resulting from chemical mimics or adenovirus-mediated overexpression increased PTGIS mRNA degradation in HEK293 cells and human umbilical vein endothelial cells. Furthermore, nitroglycerin-decreased PTGIS gene expression was prevented by miR-199a/b antagomirs or was mirrored by the enforced expression of miR-199a/b in human umbilical vein endothelial cells. In Apoe-/- mice, nitroglycerin induced the ectopic expression of miR-199a/b in the carotid arterial endothelium, decreased PTGIS gene expression, and instigated nitrovasodilator resistance, all of which were abrogated by miR-199a/b antagomirs or LNA-anti-miR-199. It is important that the effects of miR-199a/b inhibitions were abolished by adenovirus-mediated PTGIS deficiency. Moreover, the enforced expression of miR-199a/b in vivo repressed PTGIS gene expression and impaired the responses of aortic arteries to nitroglycerin/sodium nitroprusside/acetylcholine/cinaciguat/riociguat, whereas the exogenous expression of the PTGIS gene prevented nitrovasodilator resistance in Apoe-/- mice subjected to nitroglycerin infusion or miR-199a/b overexpression. Finally, indomethacin, iloprost, and SQ29548 improved vasorelaxation in nitroglycerin-infused Apoe-/- mice, whereas U51605 induced nitrovasodilator resistance. In humans, the increased expressions of miR-199a/b were closely associated with nitrate tolerance. CONCLUSIONS: Nitric oxide-induced ectopic expression of miR-199a/b in endothelial cells is required for nitrovasodilator resistance via the repression of PTGIS gene expression. Clinically, miR-199a/b is a novel target for the treatment of nitrate tolerance.

MiR-15b-5p Regulates Collateral Artery Formation by Targeting AKT3 (Protein Kinase B-3).

OBJECTIVE: To identify circulating microRNAs that are differentially expressed in severe coronary heart disease with well or poorly developed collateral arteries and to investigate their mechanisms of action in vivo and in vitro. APPROACH AND RESULTS: In our study, we identified a circulating microRNA, miR-15b-5p, with low expression that, nevertheless, characterized patients with sufficient coronary collateral artery function. Moreover, in murine hindlimb ischemia model, in situ hybridization identified that miR-15b-5p was specifically expressed in vascular endothelial cells of adductors in sham group and was remarkably downregulated after femoral artery ligation. Overexpressed miR-15b-5p significantly inhibited arteriogenesis and angiogenesis in mice. In vitro, both under basal and vascular endothelial growth factor stimulation, loss-of-function or gain-of-function studies suggested that miR-15b-5p significantly promoted or depressed the migration and proliferation of endothelial cells. We identified AKT3 (protein kinase B-3) as a direct target of miR-15b-5p. Interestingly, AKT3 deficiency by injection with Chol-AKT3-siRNA obviously suppressed arteriogenesis and the recovery of blood perfusion after femoral ligation in mice. CONCLUSIONS: These results indicate that circulating miR-15b-5p is a suitable biomarker for discriminating between patients with well-developed or poorly developed collaterals. Moreover, miR-15b-5p is a key regulator of arteriogenesis and angiogenesis, which may represent a potential therapeutic target for ischemic disease.

Que Zui tea ameliorates hepatic lipid accumulation and oxidative stress in high fat diet induced nonalcoholic fatty liver disease.

In this study, the protective effects of hot water (QW) and aqueous-ethanol extracts (QA) from Que Zui tea on non-alcoholic fatty liver disease (NAFLD) were investigated. Quantitative and qualitative analysis revealed that QW and QA were rich in polyphenols, especially 6'-O-caffeoylarbutin. Both QW and QA significantly reduced body weight and liver index, increased serum levels of high density lipoprotein cholesterol (HDL-C), and decreased the levels of total cholesterol (TC), triglyceride (TG), nonesterified free fatty acids (NEFA) and low density lipoprotein cholesterol (LDL-C) in NAFLD rats induced high fat diet. Furthermore, the contents of TC, TG, NEFA, alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in the liver tissues were inhibited after QW and QA administration. Histopathological examination showed that QW and QA significantly reduced liver lipid accumulation of NAFLD rats. In addition, QW and QA could enhance increase the activity of antioxidant (glutathione, superoxide dismutase and catalase) in the liver by regulation Nrf2 signaling pathway, thereby alleviating liver damage caused by lipid peroxidation. QW and QA activated AMPK/PPAR-α signaling pathway by increasing the expression of adiponectin and its receptor AdipoR2, thereby reducing fat production and enhancing fatty acid ß oxidation. These data suggested that QW and QA had the potential to in the prevention and treatment of NAFLD.

[Ultrasonic atomization of Shaduolika and dexamethasone for pain relief in patients with foliate papillitis].

PURPOSE: To evaluate the effect of ultrasonic atomization of Shaduolika (a traditional Chinese herb), dexamethasone for pain relief in patients with foliate papillitis. METHODS: 84 patients with foliate papillitis were divided into two groups randomly with the single-blind method. Patients in the experimental group were treated with ultrasonic atomization of Shaduolika and dexamethasone, while patients in the control group were treated by taking Niuhuangjiedu tablets (mixed traditional Chinese medicine). All the patients were observed for five days. Pain relief degree by VAS and the response to the interventions between the experimental and the control group were recorded and compared. The data was analyzed with Ridit test, Chi-square test and Student's t test using SAS6.12 software package, respectively. RESULTS: Pain scores between the experimental and the control group prior to treatment had no significant difference (U=0.1859<1.96, P>0.05), while significant difference existed in pain relief after treatment (U=5.773, P<0.01). The effect of ultrasonic atomization of Shaduolika and dexamethasone for pain relief was significantly better than the control group (U=5.233,P<0.01). CONCLUSIONS: For patients with foliate papillitis, ultrasonic atomization of Shaduolika and dexamethasone is a safe and effective method.