Modulation of monocyte activity by hepatocellular MicroRNA delivery through HBsAg particles: Implications for pathobiology of chronic hepatitis B.

BACKGROUND AND AIMS: HBsAg serves as an important immune-modulatory factor in chronic hepatitis B. One aspect of such modulation may act through monocytes, which are the major Ag-presenting cells taking up HBsAg. There is evidence for the encapsulation of hepatocellular microRNAs (miRNAs) by HBsAg particles, while its pathobiological significance is unclear. Here, we characterized the miRNA profile in patients with chronic hepatitis B and probed their association with liver inflammation. APPROACHES AND RESULTS: We collected plasma from patients that are treatment-naive with chronic hepatitis B (n = 110) and quantified total/HBsAg-enveloped miRNAs by qRT-PCR and plasma cytokines by ELISA. The biological effects of HBsAg-delivered miRNAs in monocytes were evaluated using multiple approaches. The clinical significance of candidate miRNAs and cytokines was corroborated in patients with HBV-associated advanced liver diseases. The plasma miRNA profile showed 2 major clusters, one significantly associated with HBsAg titer and the other correlated with liver inflammation. Among HBsAg-carried miRNAs, miR-939 displayed the most significant correlation with IL-8. Mechanistically, miR-939 in subviral particles enters monocytes and significantly augments IL-8 production through the mitogen-activated protein kinase (MAPK) p38 signaling pathway. Finally, the findings that miR-939 positively correlated with IL-8 level and inflammation/fibrosis stage in the cohort of HBV-associated advanced liver diseases support its causative role in the progression of liver diseases. CONCLUSIONS: HBsAg particles carry hepatocellular miRNAs, including miR-939, which enter monocytes and alter their functional status, such as IL-8 secretion. Our findings demonstrate that the HBsAg-miR-939-IL-8 axis may play a crucial role in HBV-induced hepatic necro-inflammation and the progression of advanced liver diseases.

Risk Factors Associated with Left-Sided Cardiac Valve Calcification: A Case Control Study.

OBJECTIVES: To identify risk factors associated with cardiac valve calcification that is easily detectable through routine blood tests in patients who received valve replacement therapy. METHODS: Four hundred patients with valvular heart disease who underwent valve replacement surgery between December 2009 and January 2013 were enrolled in this study. Of these, 77 had valve calcification; the other 323 did not. Multivariate logistic regression analysis was used to assess for risk factors associated with valve calcification. RESULTS: In our study population, rheumatic valve lesions were the most common reason for valve replacement. Degenerative nonstenotic valve lesion was a protective factor and degenerative stenotic valve lesion was a strong risk factor for valve calcification. Serum levels of gamma-glutamyl transferase (GGT) of between 30 and 46 IU/l and >90 IU/l and total bilirubin (TBIL) of between 15 and 20 µmol/l were positively correlated with valve calcification. Meanwhile, serum calcium (Ca2+) levels of between 2.3 and 2.4 mmol/l were negatively correlated with rheumatic valve calcification. CONCLUSIONS: Degenerative stenotic lesion is a risk factor and degenerative nonstenotic lesion a protective factor for cardiac valve calcification. Serum GGT and TBIL levels are positively correlated and serum Ca2+ levels negatively correlated with rheumatic cardiac valve calcification.

Analysis of the potential ferroptosis mechanism and multitemporal expression change of central ferroptosis-related genes in cardiac ischemia-reperfusion injury.

Acute myocardial infraction is the most severe type of coronary artery disease and remains a substantial burden to the health care system globally. Although myocardial reperfusion is critical for ischemic cardiac tissue survival, the reperfusion itself could cause paradoxical injury. This paradoxical phenomenon is known as ischemia-reperfusion injury (IRI), and the exact molecular mechanism of IRI is still far from being elucidated and is a topic of controversy. Meanwhile, ferroptosis is a nonapoptotic form of cell death that has been reported to be associated with various cardiovascular diseases. Thus, we explored the potential ferroptosis mechanism and target in cardiac IRI via bioinformatics analysis and experiment. GSE4105 data were obtained from the GEO database and consist of a rat IRI model and control. After identifying differentially expressed ferroptosis-related genes (DEFRGs) and hub genes of cardiac IRI, we performed enrichment analysis, coexpression analysis, drug-gene interaction prediction, and mRNA-miRNA regulatory network construction. Moreover, we validated and explored the multitemporal expression of hub genes in a hypoxia/reoxygenation (H/R)-induced H9C2 cell injury model under different conditions via RT-qPCR. A total of 43 DEFRGs and 7 hub genes (tumor protein p53 [Tp53], tumor necrosis factor [Tnf], hypoxia-inducible factor 1 subunit alpha [Hif1a], interleukin 6 [Il6], heme oxygenase 1 [Hmox1], X-box binding protein 1 [Xbp1], and caspase 8 [Casp8]) were screened based on bioinformatics analysis. The functional annotation of these genes revealed apoptosis, and the related signaling pathways could have association with the pathogenesis of ferroptosis in cardiac IRI. In addition, the expression of the seven hub genes in IRI models were found higher than that of control under different H/R conditions and time points. In conclusion, the analysis of 43 DEFRGs and 7 hub genes could reveal the potential biological pathway and mechanism of ferroptosis in cardiac IRI. In addition, the multitemporal expression change of hub genes in H9C2 cells under different H/R conditions could provide clues for further ferroptosis mechanism exploring, and the seven hub genes could be potential biomarkers or therapeutic targets in cardiac IRI.

miR-17-3p Contributes to Exercise-Induced Cardiac Growth and Protects against Myocardial Ischemia-Reperfusion Injury.

Limited microRNAs (miRNAs, miRs) have been reported to be necessary for exercise-induced cardiac growth and essential for protection against pathological cardiac remodeling. Here we determined members of the miR-17-92 cluster and their passenger miRNAs expressions in two distinct murine exercise models and found that miR-17-3p was increased in both. miR-17-3p promoted cardiomyocyte hypertrophy, proliferation, and survival. TIMP-3 was identified as a direct target gene of miR-17-3p whereas PTEN was indirectly inhibited by miR-17-3p. Inhibition of miR-17-3p in vivo attenuated exercise-induced cardiac growth including cardiomyocyte hypertrophy and expression of markers of myocyte proliferation. Importantly, mice injected with miR-17-3p agomir were protected from adverse remodeling after cardiac ischemia/reperfusion injury. Collectively, these data suggest that miR-17-3p contributes to exercise-induced cardiac growth and protects against adverse ventricular remodeling. miR-17-3p may represent a novel therapeutic target to promote functional recovery after cardiac ischemia/reperfusion.

Tendency for age-specific mortality with hypertension in the European Union from 1980 to 2011.

Tendency for mortality in hypertension has not been well-characterized in European Union (EU). Mortality data from 1980 to 2011 in EU were used to calculate age-standardized mortality rate (ASMR, per 100,000), annual percentage change (APC) and average annual percentage change (AAPC). The Joinpoint Regression Program was used to compare the changes in tendency. Mortality rates in the most recent year studied vary between different countries, with the highest rates observed in Slovakia men and Estonia women. A downward trend in ASMR was demonstrated over all age groups. Robust decreases in ASMR were observed for both men (1991-1994, APC = -13.54) and women (1996-1999, APC = -14.80) aged 55-65 years. The tendency of systolic blood pressure (SBP) from 1980 to 2009 was consistent with ASMR, and the largest decrease was observed among Belgium men and France women. In conclusion, SBP associated ASMR decreased significantly on an annual basis from 1980 to 2009 while a slight increase was observed after 2009. Discrepancies in ASMR from one country to another in EU are significant during last three decades. With a better understanding of the tendency of the prevalence of hypertension and its mortality, efforts will be made to improve awareness and help strict control of hypertension.

Use of microRNAs as Anti-Atherosclerosis.

MicroRNAs are a class of non-coding RNA molecules that have been reported to play a crucial role in cell signaling via post-transcriptional regulation of gene expression. There is increasing evidence showing that this class of RNA is involved in the pathogenesis of cardiovascular diseases, including atherosclerosis. More recently, it has been demonstrated that microRNAs can function to protect against the development of atherosclerosis. The primary goal of this review is to discuss the discovery, mechanism, and therapeutic use of microRNA molecules as atheroprotective agents.

Trends in age-specific cerebrovascular disease in the European Union.

Although the mortality of cerebrovascular disease (CVD) has been steadily declined in the European Union (EU), CVD remains among the major causes of death in EU. As risk factors such asobesity and diabetes mellitus are increasing, the trends of European CVD mortality remains unknown. To understand the variation in CVD mortality of different EU countries, we studied the trends in CVD mortality in EU countries over the last three decades between males and females. Age- and sex-specific mortality rates between 1980 and 2011 were calculated by data from the WHO mortality database. Joinpoint software was used to calculate annual percentage changes and to characterize trends in mortality rates over time. Our study showed that between 1980 and 2011, CVD mortality significantly decreased in both men and women across all age groups. The specific mortality trends varied largely between EU countries. The plateau trend was observed in little regions at different age groups, however, the EU as a whole displayed declined trend CVD mortality. During the last three decades, CVD mortality decreased substantially in the entire population of EU. However, despite this overall decline in CVD mortality, several areas were identified as having no change in their CVD mortality rates at different period. The whole EU needs to establish strict prevention measures toreduce the incidence of CVD risk factors.

Dynamic mitochondrial changes during differentiation of P19 embryonic carcinoma cells into cardiomyocytes.

Murine P19 embryonal carcinoma cells are multipotent cells that can differentiate into cardiomyocytes when treated with dimethyl sulfoxide. This experimental model provides an invaluable tool to study different aspects of cardiac differentiation, such as the function of cardiac­specific transcription factors and signaling pathways, and the regulation of contractile protein expression. The role of mitochondria during cardiac differentiation is unclear. In this context, we have examined the mitochondrial-related changes in undifferentiated and differentiated P19 cells. We observed that mitochondrial DNA content sharply decreased in P19 cell aggregates compared to undifferentiated cells, accompanied by decreased levels of adenosine triphosphate (ATP) and reactive oxygen species (ROS). Following the aggregation stage, the mitochondrial DNA content reached its highest level on day 7 of the differentiation process, with the intracellular ROS level showing a trend to increase, similar to cellular ATP production. In conclusion, our study on differentiating P19 embryonal carcinoma cells provides new insights into the role of mitochondria in the differentiation of P19 stem cells into beating cardiomyocytes.