ß2 adrenoceptor signaling regulates ion transport in 16HBE14o- human airway epithelial cells.

We investigated the regulation of Cl- secretion by adrenoceptors in polarized 16HBE14o- human bronchial epithelial cells. Treatment with the nonselective ß adrenoceptor agonist isoprenaline stimulated an increase in short-circuit current (ISC ), which was inhibited by the ß adrenoceptor blocker propranolol. Treatment with procaterol, an agonist specific for the ß2 adrenoceptor subtype, stimulated a similar increase in ISC , which was inhibited by the ß2 adrenoceptor antagonist ICI 118551. Inhibitors of cystic fibrosis transmembrane conductance regulator (CFTR) and calcium-activated Cl- channel (CaCC), but not K+ channel blockers, were able to inhibit the increase in ISC . "Trimultaneous" recording of ISC and intracellular cyclic adenosine monophosphate (cAMP) and Ca2+ levels in 16HBE14o- epithelia confirmed that the ISC induced by isoprenaline or procaterol involved both cAMP and Ca2+ signaling. Our results demonstrate that ß2 adrenoceptors regulate Cl- secretion in the human airway epithelium by activating apical CFTRs and CaCCs via cAMP-dependent and intracellular Ca2+ -dependent mechanisms, respectively.

The association between pre-miR-27a rs895819 polymorphism and myocardial infarction risk in a Chinese Han population.

BACKGROUND: Accumulating evidences have shown that miRNAs are directly or indirectly involved in a variety of biological processes, and closely associated with diverse human diseases, including cardiovascular diseases. SNPs locating within pri/pre-miRNA can affect miRNA processing and binding ability of target genes. MiR-27a, miR-26a-1 miR-100, miR-126 and miR-218 were reported to be associated with pathogenesis of myocardial infarction (MI). Here we aimed to evaluate the potential association of five polymorphisms in these pri/pre-miRNAs with individual susceptibility to MI in a Chinese Han population. METHODS: Genotyping was performed in 287 MI cases and 646 control subjects using polymerase chain reaction-ligase detection reaction (PCR-LDR) method. The association of these SNPs with MI risk was performed with SPSS software. RESULTS: In a logistic regression analysis, we found that AG heterozygote (OR = 0.40, 95% CI = 0.21-0.76, Pa = 0.005) or AA homozygote (OR = 0.40, 95% CI = 0.22-0.75, Pa = 0.004) of pre-miR-27a rs895819 had a reduced susceptibility to MI in comparison with GG homozygote. Similarly, a reduced risk of MI was detected when the AG and AA genotypes were combined (OR = 0.40, 95% CI = 0.22-0.74, Pa = 0.003). However, no significant association between pri-miR-26a-1 pri-miR-100, pri-miR-126 and pri-miR-218 polymorphisms and MI risk was observed under the allelic and established genetic models. Further stratified analysis of pre-miR-27a rs895819 revealed a more significant association of AG + AA genotypes with MI risk among younger, male and smoking subjects. Interestingly, AG and AA genotypes of the rs895819 polymorphism conferred about 0.17 mmol/L and 0.18 mmol/L increase in HDL-C levels compared to GG genotype. CONCLUSIONS: Our findings suggest that the pre-miR-27a rs895819 polymorphism is associated with MI susceptibility in the Chinese Han population, which probably due to influence the HDL-C levels.

Long non-coding RNAs: An emerging powerhouse in the battle between life and death of tumor cells.

Long non-coding RNAs (lncRNAs) represent a class of non-protein coding transcripts longer than 200 nucleotides that have aptitude for regulating gene expression at the transcriptional, post-transcriptional or epigenetic levels. In recent years, lncRNAs, which are believed to be the largest transcript class in the transcriptomes, have emerged as important players in a variety of biological processes. Notably, the identification and characterization of numerous lncRNAs in the past decade has revealed a role for these molecules in the regulation of cancer cell survival and death. It is likely that this class of non-coding RNA constitutes a critical contributor to the assorted known or/and unknown mechanisms of intrinsic or acquired drug resistance. Moreover, the expression of lncRNAs is altered in various patho-physiological conditions, including cancer. Therefore, lncRNAs represent potentially important targets in predicting or altering the sensitivity or resistance of cancer cells to various therapies. Here, we provide an overview on the molecular functions of lncRNAs, and discuss their impact and importance in cancer development, progression, and therapeutic outcome. We also provide a perspective on how lncRNAs may alter the efficacy of cancer therapy and the promise of lncRNAs as novel therapeutic targets for overcoming chemoresistance. A better understanding of the functional roles of lncRNA in cancer can ultimately translate to the development of novel, lncRNA-based intervention strategies for the treatment or prevention of drug-resistant cancer.

[Risk factors for recurrent wheezing in infants and young children suffering from dust mite allergy after their first wheezing].

OBJECTIVE: To investigate the risk factors for recurrent wheezing in infants and young children suffering from dust mite allergy after their first wheezing. METHODS: A total of 1 236 infants and young children who experienced a first wheezing episode and were hospitalized between August 2014 and February 2015 were enrolled, among whom 387 were allergic to dust mites. These infants and young children were followed up to 1 year after discharge. A total of 67 infants and young children who experienced 3 or more recurrent wheezing episodes within 1 year were enrolled as the recurrent wheezing group, while 84 infants and young children who did not experience recurrent wheezing during follow-up were enrolled as the control group. Univariate analysis and multivariate logistic stepwise regression analysis were performed to investigate the risk factors for recurrent wheezing in these patients. RESULTS: The univariate analysis showed that the age on admission, wheezing time before admission, Mycoplasma pneumoniae infection rate, and influenza virus infection rate were associated with recurrent wheezing. The multivariate logistic stepwise regression analysis showed that the older age on admission (OR=2.21, P=0.04) and Mycoplasma pneumoniae infection (OR=3.54, P=0.001) were independent risk factors for recurrent wheezing. CONCLUSIONS: Infants and young children who are allergic to dust mites, especially young children, have a significantly increased risk of recurrent wheezing if they are complicated by Mycoplasma pneumoniae infection during the first wheezing episode.

The association of APOC4 polymorphisms with premature coronary artery disease in a Chinese Han population.

BACKGROUND: Hypercholesterolemia arising from abnormal lipid metabolism is one of the critical risk factors for coronary artery disease (CAD), however the roles of genetic variants in lipid metabolism-related genes on premature CAD (≤ 60 years old) development still require further investigation. We herein genotyped four single nucleotide polymorphisms (SNPs) in lipid metabolism-related genes (rs1132899 and rs5167 in APOC4, rs1801693 and rs7765781 in LPA), aimed to shed light on the influence of these SNPs on individual susceptibility to early-onset CAD. METHODS: Genotyping of the four SNPs (rs1132899, rs5167, rs1801693 and rs7765781) was performed in 224 premature CAD cases and 297 control subjects (≤ 60 years old) using polymerase chain reaction-ligation detection reaction (PCR-LDR) method. The association of these SNPs with premature CAD was performed with SPSS software. RESULTS: Multivariate logistic regression analysis showed that C allele (OR = 1.50, P = 0.027) and CC genotype (OR = 2.84, P = 0.022) of APOC4 rs1132899 were associated with increased premature CAD risk, while the other three SNPs had no significant effect. Further stratified analysis uncovered a more evident association with the risk of premature CAD among male subjects (C allele, OR = 1.65, and CC genotype, OR = 3.33). CONCLUSIONS: Our data provides the first evidence that APOC4 rs1132899 polymorphism was associated with an increased risk of premature CAD in Chinese subjects, and the association was more significant among male subjects.

Role of Carbon Monoxide in Oxidative Stress-Induced Senescence in Human Bronchial Epithelium.

Prolonged or excessive stimulation from inhaled toxins may cause oxidative stress and DNA damage that can lead to stress-induced senescence in epithelial cells, which can contribute to several airway diseases. Mounting evidence has shown carbon monoxide (CO) confers cytoprotective effects. We investigated the effects of CO on oxidative stress-induced senescence in human airway epithelium and elucidated the underlying molecular mechanisms. Here, CO pretreatment reduced H2O2-mediated increases in total reactive oxygen species (ROS) production and mitochondrial superoxide in a human bronchial epithelial cell line (BEAS-2B). H2O2 treatment triggered a premature senescence-like phenotype with enlarged and flattened cell morphology accompanied by increased SA-ß-gal activity, cell cycle arrest in G0/G1, reduced cell viability, and increased transcription of senescence-associated secretory phenotype (SASP) genes. Additionally, exposure to H2O2 increased protein levels of cellular senescence markers (p53 and p21), reduced Sirtuin 3 (SIRT3) and manganese superoxide dismutase (MnSOD) levels, and increased p53 K382 acetylation. These H2O2-mediated effects were attenuated by pretreatment with a CO-containing solution. SIRT3 silencing induced mitochondrial superoxide production and triggered a senescence-like phenotype, whereas overexpression decreased mitochondrial superoxide production and alleviated the senescence-like phenotype. Air-liquid interface (ALI) culture of primary human bronchial cells, which becomes a fully differentiated pseudostratified mucociliary epithelium, was used as a model. We found that apical and basolateral exposure to H2O2 induced a vacuolated structure that impaired the integrity of ALI cultures, increased goblet cell numbers, decreased SCGB1A1+ club cell numbers, increased p21 protein levels, and increased SASP gene transcription, consistent with our observations in BEAS-2B cells. These effects were attenuated in the apical presence of a CO-containing solution. In summary, we revealed that CO has a pivotal role in epithelial senescence by regulating ROS production via the SIRT3/MnSOD/p53/p21 pathway. This may have important implications in the prevention and treatment of age-associated respiratory pathologies.

A circular intronic RNA ciPVT1 delays endothelial cell senescence by regulating the miR-24-3p/CDK4/pRb axis.

Circular RNAs (circRNAs) have been established to be involved in numerous processes in the human genome, but their function in vascular aging remains largely unknown. In this study, we aimed to characterize and analyze the function of a circular intronic RNA, ciPVT1, in endothelial cell senescence. We observed significant downregulation of ciPVT1 in senescent endothelial cells. In proliferating endothelial cells, ciPVT1 knockdown induced a premature senescence-like phenotype, inhibited proliferation, and led to an impairment in angiogenesis. An in vivo angiogenic plug assay revealed that ciPVT1 silencing significantly inhibited endothelial tube formation and decreased hemoglobin content. Conversely, overexpression of ciPVT1 in old endothelial cells delayed senescence, promoted proliferation, and increased angiogenic activity. Mechanistic studies revealed that ciPVT1 can sponge miR-24-3p to upregulate the expression of CDK4, resulting in enhanced Rb phosphorylation. Moreover, enforced expression of ciPVT1 reversed the senescence induction effect of miR-24-3p in endothelial cells. In summary, the present study reveals a pivotal role for ciPVT1 in regulating endothelial cell senescence and may have important implications in the search of strategies to counteract the development of age-associated vascular pathologies.

circGNAQ, a circular RNA enriched in vascular endothelium, inhibits endothelial cell senescence and atherosclerosis progression.

Endothelial cell senescence is one of the most important causes of vascular dysfunction and atherosclerosis. Circular RNAs (circRNAs) are endogenous RNA molecules with covalently closed-loop structures, which have been reported to be abnormally expressed in many human diseases. However, the potential role of circRNAs in endothelial cell senescence and atherosclerosis remains largely unknown. Here, we compared the expression patterns of circRNAs in young and senescent human endothelial cells with RNA sequencing. Among the differentially expressed circRNAs, circGNAQ, a circRNA enriched in vascular endothelium, was significantly downregulated in senescent endothelial cells. circGNAQ silencing triggered endothelial cell senescence, as determined by a rise in senescence-associated ß-galactosidase activity, reduced cell proliferation, and suppressed angiogenesis; circGNAQ overexpression showed the opposite effects. Mechanistic studies revealed that circGNAQ acted as an endogenous miR-146a-5p sponge to increase the expression of its target gene PLK2 by decoying the miR-146a-5p, thereby delaying endothelial cell senescence. In vivo studies showed that circGNAQ overexpression in the endothelium inhibited endothelial cell senescence and atherosclerosis progression. These results suggest that circGNAQ plays critical roles in endothelial cell senescence and consequently the pathogenesis of atherosclerosis, implying that the management of circGNAQ provides a potential therapeutic approach for limiting the progression of atherosclerosis.

Plasma-Derived Exosomal Circular RNA hsa_circ_0005540 as a Novel Diagnostic Biomarker for Coronary Artery Disease.

BACKGROUND: Exosomes exist in almost all body fluid and contain diverse biological contents which may be reflective of disease state. Circular RNAs (circRNAs) are stable in structure and have a long half-life in exosomes without degradation, thus making them reliable biomarkers. However, the potential of exosomal circRNAs as biomarkers of coronary artery disease (CAD) remains to be established. Here, we aimed to investigate the expression levels and the potential use of exosomal circRNAs as diagnostic biomarkers for CAD. METHODS: CircRNA expression levels in exosomes obtained from three plasma samples of CAD patients and three paired controls were analyzed using RNA sequencing. Exosomal circRNAs obtained in the profiling phase were then verified in two-center validation cohorts. Finally, the ability of exosomal circRNAs, adjusting for Framingham Heart Study (FHS) risk factors, was determined to discriminate between CAD patients and non-CAD controls. RESULTS: 355 circRNAs were differentially expressed between these two groups: 164 were upregulated, and 191 were downregulated. Here, we selected the potential circRNAs (fold change > 4, P < 0.05) as candidate biomarkers for further validation. Our data showed that only hsa_circ_0005540 was significantly associated with CAD (P < 0.0001). After adjustment for risk factors, hsa_circ_0005540 showed a high discriminatory power for CAD in ROC analyses (AUC = 0.853; 95%confidence interval (CI) = 0.799 - 0.906, P < 0.001). CONCLUSION: Our results suggest that plasma exosomal hsa_circ_0005540 can be used as a promising diagnostic biomarker of CAD.

Genetic susceptibility of five tagSNPs in the endothelin-1 (EDN1) gene to coronary artery disease in a Chinese Han population.

Endothelin-1 (ET-1) plays important roles in endothelial dysfunction, vascular physiology, inflammation, and atherosclerosis. Nonetheless, the role of ET-1 (EDN1) gene variants on coronary artery disease (CAD) risk remains poorly understood. The aim of the present study was to evaluate the role of EDN1 gene polymorphisms on individual susceptibility to CAD. We genotyped five tagSNPs (single-nucleotide polymorphisms) (rs6458155, rs4145451, rs9369217, rs3087459, and rs2070699) within EDN1 gene in 525 CAD patients and 675 control subjects. In a multivariate logistic regression analysis, we detected an association of rs6458155 in EDN1 gene with the CAD risk; compared with the TT homozygotes, the CT heterozygotes (odds ratio (OR) = 1.53, 95% confidence interval (CI) = 1.02-2.29, P=0.040) and the CC homozygotes (OR = 1.55, 95% CI = 1.01-2.36, P=0.043) were statistically significantly associated with the increased risk for CAD. A similar trend of the association was found in dominant model (OR = 1.53, 95% CI = 1.05-2.25, P=0.029). Consistently, the haplotype rs6458155C-rs4145451C containing rs6458155 C allele exhibited the increased CAD risk (OR = 1.22, 95% CI = 1.03-1.43, and P=0.018). In addition, CT genotype of rs6458155 conferred the increased plasma ET-1 levels compared with TT genotype (P<0.05). No association of the other four tagSNPs in EDN1 gene with CAD risk was observed. In conclusion, our study provides the first evidence that EDN1 tagSNP rs6458155 is associated with CAD risk in the Chinese Han population, which is probably due to the influence of the circulating ET-1 levels.

The Impact of tagSNPs in CXCL16 Gene on the Risk of Myocardial Infarction in a Chinese Han Population.

CXCL16 has been demonstrated to be involved in the development of atherosclerosis and myocardial infarction (MI). Nonetheless, the role of the CXCL16 polymorphisms on MI pathogenesis is far to be elucidated. We herein genotyped four tagSNPs in CXCL16 gene (rs2304973, rs1050998, rs3744700, and rs8123) in 275 MI patients and 670 control subjects, aimed at probing into the impact of CXCL16 polymorphisms on individual susceptibility to MI. Multivariate logistic regression analysis showed that C allele (OR = 1.31, 95% CI = 1.03-1.66, and P = 0.029) and CC genotype (OR = 1.84, 95% CI = 1.11-3.06, and P = 0.018) of rs1050998 were associated with increased MI risk; and C allele (OR = 0.77, 95% CI = 0.60-0.98, and P = 0.036) of rs8123 exhibited decreased MI risk, while the other two tagSNPs had no significant effect. Consistently, the haplotype rs2304973T-rs1050998C-rs3744700G-rs8123A containing the C allele of rs1050998 and A allele of rs8123 exhibited elevated MI risk (OR = 1.41, 95% CI = 1.02-1.96, and P = 0.037). Further stratified analysis unveiled a more apparent association with MI risk among younger subjects (≤60 years old). Taken together, our results provided the first evidence that CXCL16 polymorphisms significantly impacted MI risk in Chinese subjects.

Variants in ANRIL gene correlated with its expression contribute to myocardial infarction risk.

ANRIL (antisense non-coding RNA in the INK4 locus), located at the 9p21.3 locus, has been known to be closely associated with the risk of coronary artery disease (CAD). To date, studies of the 9p21.3 variants on CAD risk mainly focus on the non-coding region of ANRIL. However, the biological significance of the variants on ANRIL promoter and exons is still unknown. Here we investigate whether the variants on ANRIL promoter and exons have an effect on myocardial infarction (MI) risk, and further analyze the association of these variants with the expression of ANRIL transcript. We did not find any common variants with minor allele frequencies (MAF) larger than 5% in ANRIL promoter by sequencing 1.6kb upstream of the start codon. Unconditional logistic regression analysis revealed that two SNPs in ANRIL exons, rs10965215 and rs10738605, were significantly associated with MI risk. Further studies revealed that ANRIL transcript EU741058.1 expression levels of rs10965215 and rs10738605 risk genotypes were borderline lower than those of protective genotypes. Our data provide the evidence that the variants rs10965215 and rs10738605 in ANRIL exons contribute to MI risk in the Chinese Han population which might be correlated with the expression of its transcript EU741058.1.

Two tagSNPs rs352493 and rs3760908 within SIRT6 Gene Are Associated with the Severity of Coronary Artery Disease in a Chinese Han Population.

SIRT6 has been demonstrated to exert protective effects on endothelial cells and is closely associated with lipid metabolism, glucose metabolism, and obesity, indicating an important role in the pathogenesis and progression of coronary artery disease (CAD). Nonetheless, the biological significance of SIRT6 variants on CAD is far to be elucidated. Here we aimed to investigate the influence of SIRT6 polymorphisms on individual susceptibility and severity of CAD. Multivariate logistic regression analysis exhibited no significant association between these five polymorphisms and CAD risk in the genotype and allele frequencies. However, we found that the rs352493 polymorphism in SIRT6 exhibited a significant effect on the severity of CAD; C allele (χ(2) = 7.793, adjusted P = 0.013) and the combined CC/CT genotypes (χ(2) = 5.609, adjusted P = 0.031) presented the greater CAD severity. In addition, A allele (χ(2) = 5.208, adjusted P = 0.046) and AA (χ(2) = 4.842, adjusted P = 0.054) of rs3760908 were also associated with greater CAD severity in Chinese subjects. Our data provided the first evidence that SIRT6 tagSNPs rs352493 and rs3760908 play significant roles in the severity of CAD in Chinese Han subjects, which might be useful predictors of the severity of CAD.

Association of lincRNA-p21 Haplotype with Coronary Artery Disease in a Chinese Han Population.

lincRNA-p21 plays an important role in the pathogenesis and progression of coronary artery disease (CAD). To date, the biological significance of polymorphisms in lincRNA-p21 on CAD risk remains unknown. Here we aimed to evaluate the influence of lincRNA-p21 polymorphisms on individual susceptibility to CAD. Genotyping of four tagSNPs (rs9380586, rs4713998, rs6930083, and rs6931097) within lincRNA-p21 gene was performed in 615 CAD and 655 controls. The haplotype analysis showed that the haplotype G-A-A-G (rs9380586-rs4713998-rs6930083-rs6931097) was statistically significantly associated with the reduced risk for CAD (OR = 0.78, P = 0.023). Stratified analysis revealed that G-A-A-G haplotype was at a significantly lower risk for myocardial infarction (MI) (OR = 0.68, P = 0.010). We also found that haplotype G-A-A-G had a more pronounced decreased risk for premature CAD or MI subjects (OR = 0.67, P = 0.017 for premature CAD, and OR = 0.65, P = 0.041 for premature MI, resp.). Our data provide the first evidence that the G-A-A-G haplotype of lincRNA-p21 is associated with decreased risk of CAD and MI, particularly among premature CAD/MI in the Chinese Han population. Further studies with more subjects and in diverse ethnic populations are warranted to clarify the general validity of our findings.

Identification of the lncRNA, AK156230, as a novel regulator of cellular senescence in mouse embryonic fibroblasts.

Long noncoding RNAs (lncRNAs) have gained extensive attentions in recent years because of their potential importance in a variety of biological and pathological processes. In this study, we sought to explore the role of lncRNAs in cellular senescence. Here, we report that the lncRNA AK156230 was downregulated during replicative senescence in mouse embryonic fibroblasts (MEFs), and knockdown of AK156230 promotes a robust senescence phenotype, including increase in the numbers of the senescence-associated ß-galactosidase-positive cells, decrease of cell proliferation, accumulation of cells in the G2/M phase and reduction of autophagic activity. The cells with knockdown AK156230 expression also exhibited increased levels of p21, p53 and phosphorylated p53, and a decreased activity of CDK1. Moreover, rapamycin-induced autophagy offered cytoprotective effect and rescued cellular senescence in AK156230 knockdown cells. Gene expression profile showed that the dysregulation of autophagy and cell cycle genes contributed to the induction of cellular senescence after AK1561230 silencing. Taken together, these results suggest that downregulation of AK156230 is involved in the induction of cellular senescence through its roles in autophagy and cell cycle progression. Our study identifies AK156230 as a critical lncRNA that has a role in regulating cellular senescence in MEFs.

A TagSNP in SIRT1 gene confers susceptibility to myocardial infarction in a Chinese Han population.

SIRT1 exerts protective effects against endothelial cells dysfunction, inflammation and atherosclerosis, indicating an important role on myocardial infarction (MI) pathogenesis. Nonetheless, the effects of SIRT1 variants on MI risk remain poorly understood. Here we aimed to investigate the influence of SIRT1 polymorphisms on individual susceptibility to MI. Genotyping of three tagSNPs (rs7069102, rs3818292 and rs4746720) in SIRT1 gene was performed in a Chinese Han population, consisting of 287 MI cases and 654 control subjects. In a logistic regression analysis, we found that G allele of rs7069102 had increased MI risk with odds ratio (OR) of 1.57 [95% confidence interval (CI) = 1.15-2.16, Bonferroni corrected P (Pc) = 0.015] after adjustment for conventional risk factors compared to C allele. Similarly, the combined CG/GG genotypes was associated with the increased MI risk (OR = 1.64, 95% CI = 1.14-2.35, Pc = 0.021) compared to the CC genotype. Further stratified analysis revealed a more significant association with MI risk among younger subjects (≤ 55 years old). Consistent with these results, the haplotype rs7069102G-rs3818292A-rs4746720T containing the rs7069102 G allele was also associated with the increased MI risk (OR = 1.41, 95% CI = 1.09-1.84, Pc = 0.040). However, we did not detect any association of rs3818292 and rs4746720 with MI risk. Our study provides the first evidence that the tagSNP rs7069102 and haplotype rs7069102G-rs3818292A-rs4746720T in SIRT1 gene confer susceptibility to MI in the Chinese Han population.