Association Between Nitrite and Nitrate Intake and Risk of Gastric Cancer: A Systematic Review and Meta-Analysis.

BACKGROUND Studies have shown inconsistent associations of nitrite and nitrate intake with the risk of gastric cancer or its associated mortality. We performed a meta-analysis of observational studies to evaluate the correlation of nitrite and nitrate intake with the risk of gastric cancer. MATERIAL AND METHODS We searched for studies reporting effect estimates and 95% confidence intervals (CIs) of gastric cancer in PubMed, EMBASE, and the Cochrane Library through November 2018. The summary results of the included studies were pooled using a random-effects model. RESULTS Eighteen case-control and 6 prospective cohort studies recruiting 800 321 participants were included in this study. The summary results indicated that the highest (odds ratio [OR], 1.27; 95%CI, 1.03-1.55; P=0.022) or moderate (OR: 1.12; 95%CI, 1.01-1.26; P=0.037) nitrite intake were associated with a higher risk of gastric cancer. However, we noted that high (OR, 0.81; 95%CI, 0.68-0.97; P=0.021) or moderate (OR, 0.86; 95%CI, 0.75-0.99; P=0.036) nitrate intakes were associated with a reduced risk of gastric cancer. These associations differed when stratified by publication year, study design, country, the percentage of male participants, assessment of exposure, adjusted model, and study quality. CONCLUSIONS High or moderate nitrite intake was associated with higher risk of gastric cancer, whereas high or moderate nitrate intake was correlated with lower risk of gastric cancer.

MicroRNA-26b relieves inflammatory response and myocardial remodeling of mice with myocardial infarction by suppression of MAPK pathway through binding to PTGS2.

BACKGROUND: Myocardial infarction (MI) is a common cardiovascular disease caused by myocardial ischemia. Also, microRNA (miRNA) participates in the pathophysiology of many cardiovascular diseases, which can affect stem cell transplantation in the treatment of MI. In this study, our aim is to explore effect of miR-26b on inflammatory response and myocardial remodeling through the MAPK pathway by targeting PTGS2 in mice with MI. METHODS: Microarray data analysis was conducted to screen MI-related differentially expressed gens (DEGs). Relationship between miR-26b and PTGS2 was testified. Cardiac function, inflammatory reaction, infarct size, and myocardial fibrosis were observed. The miR-26b expression and mRNA and protein levels of, PTGS2, ERK, JNK and p38 and Bcl-2/Bax were examined. The effect of miR-26b on cell apoptosis was also analyzed. RESULTS: MiR-26b was predicted to target PTGS2 further to mediate the MAPK pathway, thus affecting MI. MiR-26b negatively targeted PTGS2. MI mice showed decreased cardiac function, as well as increased inflammatory reaction, myocardial injury, area of fibrosis and myocardial cell apoptosis. After injection of miR-26b agomir or NS-398 (PTGS2 inhibitor), inflammatory response of MI mice was attenuated and myocardial remodeling induced by MI was alleviated. CONCLUSION: These findings indicate that miR-26b inhibits PTGS2 to activate the MAPK pathway, so as to reduce inflammatory response and improve myocardial remodeling in mice with MI.

IRAK3 gene silencing prevents cardiac rupture and ventricular remodeling through negative regulation of the NF-κB signaling pathway in a mouse model of acute myocardial infarction.

Cardiac rupture and ventricular remodeling are recognized as the severe complications and major risk factors of acute myocardial infarction (AMI). This study aims to evaluate the regulatory roles of interleukin-1 receptor-associated kinase 3 (IRAK3) and nuclear factor-κB (NF-κB) signaling pathway in cardiac rupture and ventricular remodeling. Microarray analysis was performed to screen AMI-related differentially expressed genes and IRAK3 was identified. The models of AMI were established in male C57BL/6 mice to investigate the functional role of IRAK3. Afterwards, lentivirus recombinant plasmid si-IRAK3 was constructed for IRAK3 silencing. Next, cardiac function parameters were measured in response to IRAK3 silencing. The regulatory effects that IRAK3 had on myocardial infarct size and the content of myocardial interstitial collagen were analyzed. The regulation of IRAK3 silencing on the NF-κB signaling pathway was further assayed. The obtained results indicated that highly expressed IRAK3 and activated NF-κB signaling pathway were observed in myocardial tissues of mouse models of AMI, accompanied by increased expression of matrix metalloproteinase (MMP)-2/9 and tissue inhibitor of metalloproteinase 2 (TIMP-2). Notably, IRAK3 gene silencing inhibited the activation of NF-κB signaling pathway. Furthermore, IRAK3 gene silencing led to the decreased thickness of infarct area and collagen content of myocardial interstitium, alleviated diastolic, and systolic dysfunctions, as well as, facilitated cardiac functions in mice with AMI, corresponding to decreased expression of MMP-2/9 expression and increased expression of TIMP-2. Taken together, silencing of IRAK3 inactivates the NF-κB signaling pathway, and thereby impeding the cardiac rupture and ventricular remodeling, which eventually prevents AMI progression.