Selective recognition of Hg2+ ions in aqueous solution by a CdII-based metal-organic framework with good stability and vacant coordination sites.

A novel water-stable CdII-based metal-organic framework, namely {[Cd(BIBT)(TDC)]·2H2O}n (JXUST-28, BIBT = 4,7-bi(1H-imidazol-1-yl)benzo-[2,1,3]thiadiazole and H2TDC = 2,5-thiophenedicarboxylic acid), was synthesized using a mixed-ligand strategy. Structural analysis demonstrates that JXUST-28 exhibits a two-dimensional layer structure with 4-connected sql topology. Intriguingly, JXUST-28 presents good stability in boiling water (at least 5 days), common organic solvents and aqueous solutions with different pH values of 2-12 (more than 24 hours). Furthermore, fluorescence experiments revealed that JXUST-28 could sense Hg2+ ions in aqueous solution via a quenching effect with a detection limit of 0.097 µM. Meanwhile, JXUST-28 can also be regenerated at least 5 times to detect Hg2+ ions. In addition, light-emitting diode lamps, luminescent films, and test papers of JXUST-28 have been successfully developed for practical applications.

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.

Circular RNAs: Promising Biomarkers for Age-related Diseases.

Aging is a complex biological process closely linked with the occurrence and development of age-related diseases. Despite recent advances in lifestyle management and drug therapy, the late diagnosis of these diseases causes severe complications, usually resulting in death and consequently impacting social economies. Therefore, the identification of reliable biomarkers and the creation of effective treatment alternatives for age-related diseases are needed. Circular RNAs (circRNAs) are a novel class of RNA molecules that form covalently closed loops capable of regulating gene expression at multiple levels. Several studies have reported the emerging functional roles of circRNAs in various conditions, providing new perspectives regarding cellular physiology and disease pathology. Notably, accumulating evidence demonstrates the involvement of circRNAs in the regulation of age-related pathologies, including cardio-cerebrovascular disease, neurodegenerative disease, cancer, diabetes, rheumatoid arthritis, and osteoporosis. Therefore, the association of circRNAs with these age-related pathologies highlights their potential as diagnostic biomarkers and therapeutic targets for better disease management. Here, we review the biogenesis and function of circRNAs, with a special focus on their regulatory roles in aging-related pathologies, as well as discuss their potential as biological biomarkers and therapeutic targets for these diseases.

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.

CircFOXO3 rs12196996, a polymorphism at the gene flanking intron, is associated with circFOXO3 levels and the risk of coronary artery disease.

CircFOXO3 plays an important role in the pathogenesis of coronary artery disease (CAD). Single nucleotide polymorphisms (SNPs) at circRNA flanking introns may change its back-splicing and influence circRNA formation. Here, we aimed to investigate the influence of the polymorphisms at the circFOXO3 flanking introns on individual susceptibility to CAD. A total of 1185 individuals were included in the case-control study. In a multivariate logistic regression analysis, we determined that the rs12196996 G variant was significantly associated with increased CAD risk (OR = 1.36, P = 0.014). A similar trend of the association was observed in the recessive model (OR = 2.57, P = 0.003). Stratified analysis revealed a more significant association with CAD risk among younger subjects and non-smokers. Consistent with these results, the haplotype rs12196996G-rs9398171C containing rs12196996G allele was also associated with increased CAD risk (OR = 1.31, P = 0.013). Further investigation revealed that the rs12196996 GG genotype was associated with decreased circFOXO3 expression, but not linear FOXO3 levels. Taken together, our data provide the first evidence that the rs12196996 polymorphism at the circFOXO3 gene flanking intron is associated with CAD risk in the Chinese Han population, which is probably due to influence circFOXO3 levels.

Selective Conversion of 5-Hydroxymethylfuraldehyde Using Cp*Ir Catalysts in Aqueous Formate Buffer Solution.

The highly selective hydrogenation/hydrolytic ring-opening reaction of 5-hydroxymethylfuraldehyde (5-HMF) was catalyzed by homogeneous Cp*Ir(III) half-sandwich complexes to produce 1-hydroxy-2,5-hexanedione (HHD). Adjustment of pH was found to regulate the distribution of products and reaction selectivity, and full conversion of 5-HMF to HHD with 99 % selectivity was achieved at pH 2.5. A mechanistic study revealed that the hydrolysis/ring-opening reaction of 2,5-bis-(hydroxymethyl)furan is the important intermediate reaction step. In addition, an isolated yield of 85 % for HHD was obtained in a 10 g-scale experiment, and the reaction with fructose as the starting material also led to a 98 % GC yield (71.9 % to fructose) of HHD owing to the excellent tolerance of the catalyst under acidic conditions.

Alkanes from Bioderived Furans by using Metal Triflates and Palladium-Catalyzed Hydrodeoxygenation of Cyclic Ethers.

Using a metal triflate and Pd/C as catalysts, alkanes were prepared from bioderived furans in a one-pot hydrodeoxygenation (HDO) process. During the reaction, the metal triflate plays a crucial role in the ring-opening HDO of furan compounds. The entire reaction process has goes through two major phases: at low temperatures, saturation of the exocyclic double bond and furan ring are catalyzed by Pd/C; at high temperatures, the HDO of saturated furan compounds is catalyzed by the metal triflate. The reaction mechanism was verified by analyzing the changes of the intermediates during the reaction. In addition, different metal triflates, solvents, and catalyst recycling were also investigated.

Evaluating the clinical feasibility: The direct bisulfite genomic sequencing for examination of methylated status of protocadherin10 (PCDH10) promoter to predict the prognosis of gastric cancer.

OBJECTIVE: To elucidate the clinical significance of the methylated status of CpG site count of PCDH10 promoter in the survival prediction in gastric cancer (GC). METHODS: In the previous study, we demonstrated that the methylated CpG site count was significantly associated with the overall survival (OS) of GC patients by using the bisulfite genomic sequencing (BGS) with no less than five clones per sample. It was so complex and expensive for patients to undergo the BGS clones. In this study, we detected the different CpG site counts (hypermethylated and hypomethylated) of PCDH10 DNA promoter in GC samples of 471 patients by directly bisulfite genomic sequencing (D-BGS) without any clone. Furthermore, we evaluated the relationships between the methylated status of PCDH10 promoter and OS. RESULTS: Two hundred and fifty-seven of 471 (54.6%) GC patients were identified to present with PCDH10 promoter methylation by D-BGS. Patients who presented with 5 or more methylated CpG site counts of PCDH10 promoter had significantly poorer prognosis than patients who with less than 5 methylated CpG site counts of PCDH10 promoter (p= 0.039). With the multivariate survival analysis, we demonstrated that T stage, N stage and the hypermethylated CpG site counts of PCDH10 DNA promoter were the independent predictors of OS of GC patients. In addition, the hypermethylated CpG site counts of PCDH10 DNA promoter had smaller Akaike information criterion (AIC) and Bayesian information criterion (BIC) values than the other two independent predictors of the OS, indicating the hypermethylated CpG site counts of PCDH10 DNA promoter as the best prognostic predictor of GC. CONCLUSIONS: Our present findings suggested that the hypermethylated CpG site counts of PCDH10 DNA promoter for evaluating the prognosis of GC was reasonable by using the D-BGS.

Evaluating the clinical feasibility: The direct bisulfite genomic sequencing for examination of methylated status of E3 ubiquitin ligase RNF180 DNA promoter to predict the survival of gastric cancer.

BACKGROUND: E3 ubiquitin ligase Ring finger protein 180 (RNF180) has been identified as a novel tumor suppressor in gastric cancer and the methylated CpG site count of RNF180 DNA promoter can predict the prognosis for gastric cancer patients. OBJECTIVE: In the previous study, we demonstrated that methylated CpG site count of RNF180 DNA promoter was significantly associated with the survival of patients with gastric cancer using the bisulfite genomic sequencing (BGS) in the gastric cancer tissue with five clones per sample. It was so complicate for each patient underwent the BGS detection with clones. It is important to explore a simple, rapid and accurate method to detect methylated CpG site count to predicting the prognosis for gastric cancer patients. METHODS: At present study, we detected hypermethylated and hypomethylated CpG site count of RNF180 DNA promoter in samples of 480 gastric cancer patients by direct bisulfite sequencing. RESULTS: We found that patients who possessed seven or less hypermethylated CpG sites of RNF180 DNA promoter had much better survival (p= 0.008), which was similar to our previous research results by using the BGS with clones. With the multivariate survival analysis, we found that T stage, N stage and hypermethylated CpG site count of RNF180 DNA promoter were the independent predictors of prognosis for gastric cancer patients. CONCLUSIONS: hypermethylated CpG site count of RNF180 DNA promoter for evaluating the prognosis of gastric cancer was reasonable by using the direct bisulfite sequencing.