The 3C-like protease (3CL(pro)) of severe acute respiratory syndrome-associated coronavirus (SARS-CoV) is one of the most promising targets for discovery of drugs against SARS, because of its critical role in the viral life cycle. In this study, a natural compound called quercetin-3-beta-galactoside was identified as an inhibitor of the protease by molecular docking, SPR/FRET-based bioassays, and mutagenesis studies. Both molecular modeling and Q189A mutation revealed that Gln189 plays a key role in the binding. Furthermore, experimental evidence showed that the secondary structure and enzymatic activity of SARS-CoV 3CL(pro) were not affected by the Q189A mutation. With the help of molecular modeling, eight new derivatives of the natural product were designed and synthesized. Bioassay results reveal salient features of the structure-activity relationship of the new compounds: (1) removal of the 7-hydroxy group of the quercetin moiety decreases the bioactivity of the derivatives; (2) acetoxylation of the sugar moiety abolishes inhibitor action; (3) introduction of a large sugar substituent on 7-hydroxy of quercetin can be tolerated; (4) replacement of the galactose moiety with other sugars does not affect inhibitor potency. This study not only reveals a new class of compounds as potential drug leads against the SARS virus, but also provides a solid understanding of the mechanism of inhibition against the target enzyme.

Aim Growth differentiation factor 15 (GDF15) is a cytokine highly expressed in states of inflammatory stress. We aimed to study the clinical correlates and prognostic significance of plasma GDF15 in heart failure with preserved ejection fraction (HFpEF) vs. reduced ejection fraction(HFrEF), compared with N‐terminal pro‐brain natriuretic peptide (NT‐proBNP), an indicator of haemodynamic wall stress. Methods Plasma GDF15 and NT‐proBNP were prospectively measured in 916 consecutive patients with HFrEF (EF <50%; n = 730) and HFpEF (EF ≥50%; n = 186), and measured again at 6 months in 488 patients. Patients were followed up for a composite outcome of death or first HF rehospitalization. Results Median GDF15baseline values were similarly elevated in HFpEF [2862 (1812 represent the 25th percentile and 4176 represent the 75th percentile) ng/L] and HFrEF [2517 (1555, 4030) ng/L] (P = 0.184), whereas NT‐proBNP was significantly lower in HFpEF than HFrEF (1119 ng/L vs. 2335 ng/L, P < 0.001). Independent correlates of GDF15baseline were age, systolic blood pressure, New York Heart Association (NYHA) class, diabetes, atrial fibrillation, sodium, haemoglobin, creatinine, diuretic therapy, high sensitivity troponin T (hsTnT) and NT‐proBNP (all P < 0.05). During a median follow‐up of 23 months, there were 379 events (307 HFrEF, 72 HFpEF). GDF15 remained a significant independent predictor for composite outcome even after adjusting for important clinical predictors including hsTnT and NT‐proBNP (adjusted hazard ratio 1.76 per 1 Ln U, 95% confidence interval 1.39–2.21; P < 0.001), regardless of HF group (Pinteraction = 0.275). GDF15baseline provided incremental prognostic value when added to clinical predictors, hsTnT and NT‐proBNP (area under receiver operating characteristic curve increased from 0.720 to 0.740, P < 0.019), with a net reclassification improvement of 0.183 (P = 0.004). Patients with ≥20% GDF156months increase had higher risk for composite outcome (adjusted hazard ratio 1.68, 95% confidence interval 1.15–2.45; P = 0.007) compared with those with GDF156months within ± 20% of baseline. Conclusions The similarly elevated levels and independent prognostic utility of GDF15 in HFrEF and HFpEF suggest that beyond haemodynamic stress (NT‐proBNP), inflammatory injury (GDF15) may play an important role in both HF syndromes.

MicroRNAs (miRNAs) are non-coding RNAs that play essential roles in modulating the gene expression in almost all biological events. In the past decade, the involvement of miRNAs in various cardiovascular disorders has been explored in numerous in vitro and in vivo studies. In this paper, studies focused upon the discovery of miRNAs, their target genes, and functionality are reviewed. The selected miRNAs discussed herein have regulatory effects on target gene expression as demonstrated by miRNA/3′ end untranslated region (3′UTR) interaction assay and/or gain/loss-of-function approaches. The listed miRNA entities are categorized according to the biological relevance of their target genes in relation to three cardiovascular pathologies, namely cardiac hypertrophy, fibrosis, and apoptosis. Furthermore, comparison across 86 studies identified several candidate miRNAs that might be of particular importance in the ontogenesis of cardiovascular diseases as they modulate the expression of clusters of target genes involved in the progression of multiple adverse cardiovascular events. This review illustrates the involvement of miRNAs in diverse biological signaling pathways and provides an overview of current understanding of, and progress of research into, of the roles of miRNAs in cardiovascular health and disease.

Heart failure (HF) imposes significant economic and public health burdens upon modern society. It is known that disturbances in neurohormonal status play an important role in the pathogenesis of HF. Therapeutics that antagonize selected neurohormonal pathways, specifically the renin-angiotensin-aldosterone and sympathetic nervous systems, have significantly improved patient outcomes in HF. Nevertheless, mortality remains high with about 50% of HF patients dying within five years of diagnosis thus mandating ongoing efforts to improve HF management. The discovery of short noncoding microRNAs (miRNAs) and our increasing understanding of their functions, has presented potential therapeutic applications in complex diseases, including HF. Results from several genome-wide miRNA studies have identified miRNAs differentially expressed in HF cohorts suggesting their possible involvement in the pathogenesis of HF and their potential as both biomarkers and as therapeutic targets. Unravelling the functional relevance of miRNAs within pathogenic pathways is a major challenge in cardiovascular research. In this article, we provide an overview of the role of miRNAs in the cardiovascular system. We highlight several HF-related miRNAs reported from selected cohorts and review their putative roles in neurohormonal signaling.

The handling of chemicals in the laboratory presents a challenge in instructing large class sizes and when students are relatively new to the laboratory environment. In this work, we describe and demonstrate an augmented reality colorimetric titration tool that operates out of the smartphone or tablet of students. It allows multiple students to conduct the exercise at the same time, respond quickly to actions made, and correctly depict the colors associated with changes in pH values for the indicator used. The tool imbues unparalleled realism in the conduct of the experiment and offers to strongly help students acquire bench skills with minimal use of liquid chemicals, thereby reducing handing risks for them and resulting in lower negative impacts on the environment. The feedback received from undergraduate students that participated in an initial small test exercise with the tool corroborates this.

There is a potential role for the prognostic use of high-sensitivity troponin assays, particularly hsTnT, in men and women with HFpEF. The predictive association of hsTnI with outcome appears strongest in men with HFpEF.

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