The microarray identification circular RNA hsa_circ_0105015 up-regulated involving inflammation pathway in essential hypertension.

BACKGROUND: Essential hypertension (EH) is an inflammatory disease, and endothelial dysfunction induced by chronic inflammation is one of the pathogeneses of EH. The expression of some inflammatory mediators may be regulated by the interaction of circular RNAs (circRNAs) and microRNAs (miRNAs). METHODS: An Agilent human circRNA microarray was used to identify the expression profile of circRNAs in EH. qRT-PCR was used to evaluate the relative expression of circRNAs in 48 pairs of human whole blood samples (sex and age ± 3 years matched) and endothelial cells. TNF-α was applied to induce endothelial cells inflammation. CircRNA-miRNA network was predicted by MiRanda software. RESULTS: There were 287 circRNAs differentially expressed in the microarray. The top 10 up-regulated circRNAs in the EH group were hsa_circ_0014243, hsa_circ_0133228, hsa-circRNA14116-3, hsa_circ_0079536, hsa-circRNA13649-1, hsa_circ_0117886, hsa_circ_0007075, hsa-circRNA15285-1, hsa-circRNA10088-9, and hsa-circRNA14119-10; the top 10 down-regulated circRNAs were hsa_circ_0100094, hsa_circ_0127342, hsa_circ_0093773, hsa_circ_0096334, hsa_circ_0131618, hsa_circ_0063886, hsa_circ_0097804, hsa_circ_0126640, hsa-circRNA8935-1, and hsa_circ_0039978 (fold change in descending order). Hsa_circ_0105015 has two predicted binding sites with hsa-miR-637. The relative expression of hsa_circ_0105015 in EH patients was significantly higher than healthy controls (P = .002), and similar results appeared in TNF-α-induced endothelial cells. The area under the curve after hsa_circ_0105015 combined with hsa-miR-637 was 0.703, P < .001. CONCLUSION: Hyperexpression of hsa_circ_0105015 is a significant risk factor of EH and its association with EH involves inflammatory pathways. Hyperexpression of hsa_circ_0105015 combined with hypoexpression of hsa-miR-637 indicates vascular inflammation or endothelial dysfunction and has potential as a biomarker for early diagnosis of EH.

Up-regulation of circular RNA hsa_circ_0037909 promotes essential hypertension.

AIMS: Essential hypertension (EH) is a high prevalence disease facing a public health challenge. People were little known about the genetics of diagnosing the cause of EH. Circular RNAs that have a continuous cycle of covalent closure, without affected by RNA exonuclease, and are more stable and hard to degrade may involve into the molecule regulation mechanism of EH as an important biomedical. METHODS: qRT-PCR was used to analyze circRNAs in total volume of human blood and the induced human aortic endothelial cells (HAECs) and human umbilical vein endothelial cells (HUVECs). Our case-control study was involved with 48 pairs of case controls with sex and age (±3 years) match. We conducted t test, Pearson's χ2 test, and receiver operating characteristics (ROC) curve analysis for the corresponding analysis. RESULTS: The expression level of hsa_circ_0037909 in EH patients was significantly higher than that in the healthy controls (P = 0.007), and the expression level of hsa-miR-637 in EH patients was significantly lower in than that in the healthy controls (P = 0.039); the same result appears in the HAECs and HUVECs. Hsa-miR-637 (adjusted P = 0.018), hsa_circ_0037909 (adjusted P = 0.005), HDL (adjusted P = 0.024), and serum creatinine (adjusted P = 0.014) were brought into the model which performed logistic regression analysis. The combination of two RNAs was excellent (P < 0.001) through ROC curve analysis. Hsa_circ_0037909 was significantly positively correlated with serum creatinine (P < 0.001) and low-density lipoprotein (LDL) (P = 0.017). CONCLUSIONS: Our findings suggested that the combination of hsa_circ_0037911 and hsa-miR-637 may be a significant important biomarker for early diagnosis of EH. Hsa_circ_0037909 may affect serum creatinine or LDL leading to the formation of EH.

Association between Homocysteine Levels and All-cause Mortality: A Dose-Response Meta-Analysis of Prospective Studies.

Plasma homocysteine (Hcy) levels may be associated with all-cause mortality risk. However, the results of this association are conflicting and the dose-response relationship between them has not been clearly defined. In this meta-analysis, we conducted a systematic literature search of the PubMed, Embase, Web of Science and Cochrane Library for the relevant articles dated up to February 2017. Pooled relative risks (RRs) and corresponding 95% confidence intervals (CIs) were calculated to evaluate the estimates, and the dose-response relationship was estimated using a restricted cubic spline model. Eleven prospective studies (4,110 deaths among 27,737 individuals) were included. The summary RR of all-cause mortality for the highest Hcy category vs. the lowest Hcy category was 1.80 (95% CI: 1.51, 2.14) with the random effects model. In dose-response meta-analysis, Hcy levels were significantly associated with all-cause mortality risk in a linear fashion (p nonlinearity = 0.255), and the risk of all-cause mortality increased by 33.6% for each 5 µmol/L increase in Hcy levels (RR = 1.336, 95% CI: 1.254-1.422, p < 0.001). Findings from this dose-response meta-analysis suggest that Hcy levels are linearly and positively associated with risk of all-cause mortality.

Hypomethylation of the Toll-like receptor-2 gene increases the risk of essential hypertension.

Studies on the etiology of essential hypertension (EH) have demonstrated that chronic inflammation contributes to the onset and development of elevated blood pressure. Toll­like receptors (TLRs), important immune receptors, serve a role in chronic inflammation and are associated with EH. In the present study, 96 patients with EH, and 96 age­ and sex­matched healthy controls were recruited, and eight cytosine­phosphate­guanine (CpG) dinucleotides (CpG1­8) were analyzed using bisulfite pyrosequencing technology. It was observed that the methylation levels of all of the eight CpG dinucleotides were decreased in the EH group compared with the control group; however, only CpG1 (2.83±1.34 vs. 3.44±1.75; P=0.009), CpG6 (3.58±3.64 vs. 8.30±4.13; P<0.001) and CpG8 (8.91±5.32 vs. 11.33±3.87; P<0.001) were significantly different, as demonstrated by paired t­test analysis. In addition, logistic regression analysis demonstrated that CpG6 hypomethylation was a risk factor of EH (odds ratio=1.10; adjusted P=0.009), and CpG6 methylation level was observed to be negatively correlated with systolic blood pressure (r=­0.304; P<0.001) and diastolic blood pressure (r=­0.329; P<0.001). Additionally, receiver operating characteristic curve analysis demonstrated that a methylation level of 7.5% for CpG6 (area under the curve, 0.834; P<0.001) was an appropriate threshold value to predict the risk of EH. With generalized multifactor dimensionality reduction, a potential gene­gene interaction between CpG6 and CpG8 (P=0.001), and gene­environment interactions between smoking, alcohol consumption, CpG6, CpG7 and CpG8 (P=0.011), were observed. In conclusion, the results of the present study demonstrated that hypomethylation of the TLR2 promoter, particularly CpG6, was associated with the risk of EH in this population. Additionally, a gene­gene interaction between CpG6 and CpG8, and interactions between environmental factors, including smoking and alcohol consumption, and CpG6, CpG7 and CpG8, may be associated with the risk of EH.

Preliminary analysis of the association between methylation of the ACE2 promoter and essential hypertension.

The aim of the present study was to investigate whether methylation of the angiotensin I converting enzyme 2 (ACE2) promoter increases the risk of essential hypertension (EH). A total of 96 patients with EH were recruited and 96 sex­ and age­matched healthy controls. Methylation of 5 CpG dinucleotides in the ACE2 promoter was quantified using bisulfite pyrosequencing. Logistic regression and multiple linear regression were used to adjust for confounding factors and the generalized multifactor dimensionality reduction (GMDR) method was applied to investigate high­order interactions. Methylation of CpG4 (adjusted P=0.020) and CpG5 (adjusted P=0.036) was significantly higher in patients with EH, with frequency 97.56±5.65% and 12.75±4.15% in EH individuals and 95.73±9.11% and 11.47±3.67% in healthy controls. GMDR detected significant interaction among the 5 CpG sites (odds ratio=7.33, adjusted P=0.01). Furthermore, receiver operating characteristic curves identified that CpG5 methylation was a significant predictor of EH. Notably, CpG2 methylation was significantly higher in males than in females (adjusted P=0.018). Conversely, CpG5 methylation was significantly lower in males (adjusted P=0.032). These results indicated that aberrant methylation of the ACE2 promoter may be associated with EH risk. In addition, sex may significantly influence ACE2 methylation.

Homocysteine levels and risk of essential hypertension: A meta-analysis of published epidemiological studies.

BACKGROUND: Plasma homocysteine (Hcy) levels may be associated with essential hypertension (EH). However, the results of previous studies on this association are inconsistent. METHODS: In this meta-analysis, we performed a systematic literature search of the Embase, PubMed, Cochrane Library, and Web of Science for the relevant articles dated up to March 2016. Pooled odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were used to evaluate the estimates. RESULTS: We included 11 studies with a total of 16,571 participants (4,830 EH cases). We found that elevated Hcy levels were associated with the risk of EH (pooled OR: 1.36, 95% CI: 1.02-1.80 in the random-effects model). However, subsequent subgroup analyses showed that elevated Hcy levels increased the EH risk in retrospective studies (OR: 1.82, 95% CI: 1.53-2.16; p < 0.001) and unadjusted studies (OR: 1.72, 95% CI: 1.43-2.07; p < 0.001), but not in perspective studies (OR: 0.99, 95% CI: 0.73-1.28; p = 0.939) and adjusted studies (OR: 1.21, 95% CI: 0.85-1.72; p = 0.297). No significant publication bias was found (p = 0.876 for Begg's test, p = 0.144 for Egger's test). CONCLUSION: Plasma Hcy levels are associated with EH risk. However, our findings do not support a causal association between Hcy levels and EH.

Interactions between CYP11B2 Promoter Methylation and Smoking Increase Risk of Essential Hypertension.

Aldosterone synthase (CYP11B2) is closely linked to essential hypertension (EH). However, it remains unclear whether the methylation of the CYP11B2 promoter is involved in the development of EH in humans. Our study is aimed at evaluating the contribution of CYP11B2 promoter methylation to the risk of EH. Methylation levels were measured using pyrosequencing technology in 192 participants in a hospital-based case-control study. Logistic regression and multiple linear regression analyses were utilized to adjust for confounding factors and the GMDR method was applied to investigate high-order gene-environment interactions. Although no significant result was observed linking the four analyzed CpG sites to EH, GMDR detected significant interactions among CpG1, CpG3, CpG4, and smoking correlated with an increased risk of EH (OR = 4.62, adjusted P = 0.011). In addition, CpG2 (adjusted P = 0.013) and CpG3 (adjusted P = 0.039) methylation was significantly lower in healthy males than in healthy females. Likewise, after adjusting for confounding factors, CpG2 methylation (adjusted P = 0.007) still showed significant gender-specific differences among the participants of the study. CpG1 (P = 0.009) site was significantly positively correlated with age, and CpG3 (P = 0.007) and CpG4 (P = 0.006) were both inversely linked to smoking. Our findings suggest that gene-environment interactions are associated with the pathogenesis and progression of EH.

Association of AGTR1 Promoter Methylation Levels with Essential Hypertension Risk: A Matched Case-Control Study.

UNLABELLED: The purpose of the present study was to investigate whether methylation of the angiotensin II type 1 receptor (AGTR1) promoter contributed to the risk of essential hypertension (EH). A total of 96 EH cases and 96 gender- and age-matched healthy controls were recruited. Methylation of 8 CpG dinucleotides (CpG1-8) in the AGTR1 promoter was examined using the bisulphite pyrosequencing technology. Three CpG dinucleotides (CpG6-8) could not be well sequenced, therefore only the remaining 5 CpG sites were analysed. A significantly lower CpG1 methylation level was identified in EH cases than in controls (cases vs. CONTROLS: 6.74 ± 4.32% vs. 9.66 ± 5.45%, p = 0.007), and no significant association was observed in the remaining analyses. In addition, significantly lower CpG1 (p = 0.028) and higher CpG2 (p = 0.032) methylation levels were observed in males than in females. In the breakdown association test by gender, a higher CpG1 methylation level was also identified in EH in both males (p = 0.034) and females (p = 0.020). Receiver operating characteristic curves showed that CpG1 methylation was a significant predictor of EH. Furthermore, CpG1 methylation was inversely correlated with uric acid levels in controls. The present study suggests that CpG1 hypomethylation in the AGTR1 promoter is likely associated with the risk of EH in the population assessed.

Detection of circulating tumor cells in peripheral blood from patients with gastric cancer using microRNA as a marker.

Recently, the detection of occult cancer cells in peripheral blood has received a great deal of attention regarding the prediction of postoperative cancer recurrence and for novel strategies of adjuvant therapy. The aim of this study was to establish a new molecular diagnostic method of detecting circulating tumor cells. Gastric cancer SGC-7901 cells in 2 ml blood from healthy volunteers were serially diluted. Additional peripheral blood samples were collected from 90 patients and 27 healthy volunteers. Real-time reverse transcription-polymerase chain reaction was used to detect the levels of microRNA-106a (miR-106a) and microRNA-17 (miR-17). Receiver operating characteristics (ROC) curves were constructed. In recovery experiments, a significant correlation between the number of cancer cells and the levels of both miR-106a (r = -0.906, p = 0.037) and miR-17 (r = -0.912, p = 0.031) was found. In preoperative and postoperative patient groups, miR-106a and miR-17 levels were significantly higher than those in controls. The areas under the ROC curve for miR-106a, miR-17, and combination were 0.684 (p = 0.0066), 0.743 (p = 0.0001), and 0.741 (p = 0.0002), respectively. Our results indicate that the detection of miRNA in peripheral blood may be a novel tool for monitoring circulating tumor cells in patients with gastric cancers.