AimsLoop diuretics are first‐line medications for congestive heart failure (CHF); however, they are associated with serious adverse effects, including decreased renal function, and sympathetic nervous and renin–angiotensin system activation. We tested whether tolvaptan, a vasopressin V2‐receptor antagonist, could reduce unfavourable furosemide‐induced effects during CHF treatment.Methods and resultsSixty patients emergently hospitalized owing to CHF‐induced dyspnea were randomly assigned to receive either 40 mg intravenous furosemide daily or 7.5 mg oral tolvaptan for 5 days after admission. Both groups also received intravenous carperitide and canrenoate potassium. As results, baseline patient characteristics were similar between the furosemide (n = 30) and the tolvaptan (n = 30) groups, with no significant difference in 5 day urine volume or fluid balance. Brain natriuretic peptide and body weight improvements were similar between groups. However, serum creatinine (Cr) level did not increase, and the incidence of worsening renal function was significantly lower in the tolvaptan group. Consequently, the Cr increase to gain 1000 mL urine was 2.5‐fold lower in the tolvaptan group. Furthermore, the blood urea nitrogen (BUN)/Cr ratio significantly decreased in the tolvaptan group, suggesting that renal perfusion was preserved, and urea reuptake and passive water reabsorption were suppressed following tolvaptan treatment. Although catecholamine improvements after treatment were not significantly different, plasma renin activity was enhanced in the furosemide group.ConclusionsAs compared with furosemide, tolvaptan in patients with acute heart failure is associated with comparable decongestion, better preservation of renal function and less activation of renin–angiotensin system. (UMIN 000014134).

Cytoplasmic RIG-I-like receptor (RLR) proteins in mammalian cells recognize viral RNA and initiate an antiviral response that results in IFN-β induction. Melanoma differentiation-associated protein 5 (MDA5) forms fibers along viral dsRNA and propagates an antiviral response via a signaling domain, the tandem CARD. The most enigmatic RLR, laboratory of genetics and physiology (LGP2), lacks the signaling domain but functions in viral sensing through cooperation with MDA5. However, it remains unclear how LGP2 coordinates fiber formation and subsequent MDA5 activation. We utilized biochemical and biophysical approaches to observe fiber formation and the conformation of MDA5. LGP2 facilitated MDA5 fiber assembly. LGP2 was incorporated into the fibers with an average inter-molecular distance of 32 nm, suggesting the formation of hetero-oligomers with MDA5. Furthermore, limited protease digestion revealed that LGP2 induces significant conformational changes on MDA5, promoting exposure of its CARDs. Although the fibers were efficiently dissociated by ATP hydrolysis, MDA5 maintained its active conformation to participate in downstream signaling. Our study demonstrated the coordinated actions of LGP2 and MDA5, where LGP2 acts as an MDA5 nucleator and requisite partner in the conversion of MDA5 to an active conformation. We revealed a mechanistic basis for LGP2-mediated regulation of MDA5 antiviral innate immune responses.

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The degQ gene of Bacillus subtilis (natto), encoding a small peptide of 46 amino acids, is essential for the synthesis of extracellular poly-gamma-glutamate (␥PGA). To elucidate the role of DegQ in ␥PGA synthesis, we knocked out the degQ gene in Bacillus subtilis (natto) and screened for suppressor mutations that restored ␥PGA synthesis in the absence of DegQ. Suppressor mutations were found in degS, the receptor kinase gene of the DegS-DegU two-component system. Recombinant DegS-His 6 mutant proteins were expressed in Escherichia coli cells and subjected to an in vitro phosphorylation assay. Compared with the wild type, mutant DegS-His 6 proteins showed higher levels of autophosphorylation (R208Q, M195I, L248F, and D250N), reduced autodephosphorylation (D250N), reduced phosphatase activity toward DegU, or a reduced ability to stimulate the autodephosphorylation activity of DegU (R208Q, D249G, M195I, L248F, and D250N) and stabilized DegU in the phosphorylated form. These mutant DegS proteins mimic the effect of DegQ on wild-type DegSU in vitro. Interestingly, DegQ stabilizes phosphorylated DegS only in the presence of DegU, indicating a complex interaction of these three proteins.Extracellular poly-gamma-glutamate (␥PGA) is a glutamate polymer linked through a gamma-peptide bond produced outside the cells by bacilli, including Bacillus subtilis, B. licheniformis, and B. anthracis, and Staphylococcus epidermidis (4). It acts as a nutrient reservoir to prevent starvation in the stationary phase and as a barrier against bacteriophage or phagocytotic attack by the host immune system (4, 12, 14, 16). Microbial functions that are not essential for the life cycle under laboratory conditions but that are required for survival in the natural environment are sometimes lost in domesticated laboratory strains. The loss of the ability to synthesize ␥PGA in a laboratory strain of B. subtilis is an example of such an event, and a mutation in degQ is involved in it (30).degQ function was characterized mainly through studies of the ␥PGA-negative laboratory lineage B. subtilis 168. degQ encodes a small peptide of 46 amino acids, and it is a pleiotropic regulator of degradation enzymes, including alkaline protease, ␣-amylase, and levansucrase (1). The expression of degQ is dependent on comA, the global transcriptional regulator in the stationary phase, and is strongly induced under dense-cell conditions (18). The regulation of these exoenzymes by degQ requires the presence of the degS-degU operon that comprises a two-component system (17, 18). The sensor histidine kinase DegS has four activities: it acts as a self-kinase (autophosphorylation of His189), a self-phosphatase (autodephosphorylation), a phosphotransferase (phosphorylation of Asp56 of DegU), and a phosphatase (dephosphorylation of DegU) (5,6,15,20,31). Exoenzyme expression is controlled directly by DegU, a DNA-binding protein, and DegU phosphorylation by DegS (DegU-P i ) enhances it (25,29,34). A recent study reported that DegQ stimulates phosphate transfer from phospho...

Twelve benzylisoquinoline alkaloids, including pavine and phenanthroindolizidine types, were isolated from a MeOH/CH2Cl2 extract of Cryptocarya laevigata (stem bark) through bioactivity-guided fractionation for antitumor effects. Selected compounds were evaluated for antiproliferative activity against five human tumor cell lines, including a multidrug-resistant subline. Since more common 2,3,8,9-tetrasubstituted pavine alkaloids, such as crychine (3), exhibit very mild or no cytotoxicity, this compound type has not been well investigated for antitumor activity. Thus, this report is the first discovery of a 7-hydroxylated pavine alkaloid, (−)-neocaryachine (1), to demonstrate strong antiproliferative activity, with IC50 values of 0.06 to 0.41 µM against five tested tumor cell lines, including an MDR subline. Further mechanism of action studies revealed that 1 impacts the cellular S-phase by inducing DNA double-strand breaks.

Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has rapidly spread across the world. Inactivating the virus in saliva and the oral cavity represents a reasonable approach to prevent human-to-human transmission because the virus is easily transmitted through oral routes by dispersed saliva. Persimmon-derived tannin is a condensed type of tannin that has strong antioxidant and antimicrobial activity. In this study, we investigated the antiviral effects of persimmon-derived tannin against SARS-CoV-2 in both in vitro and in vivo models. We found that persimmon-derived tannin suppressed SARS-CoV-2 titers measured by plaque assay in vitro in a dose- and time-dependent manner. We then created a Syrian hamster model by inoculating SARS-CoV-2 into hamsters’ mouths. Oral administration of persimmon-derived tannin dissolved in carboxymethyl cellulose before virus inoculation dramatically reduced the severity of pneumonia with lower virus titers compared with a control group inoculated with carboxymethyl cellulose alone. In addition, pre-administration of tannin to uninfected hamsters reduced hamster-to-hamster transmission of SARS-CoV-2 from a cohoused, infected donor cage mate. These data suggest that oral administration of persimmon-derived tannin may help reduce the severity of SARS-CoV-2 infection and transmission of the virus.

Memory is initially labile but can be consolidated into stable long-term memory (LTM) that is stored in the brain for extended periods. Despite recent progress, the molecular and cellular mechanisms underlying the intriguing neurobiological processes of LTM remain incompletely understood. Using the Drosophila courtship conditioning assay as a memory paradigm, here, we show that the LIM homeodomain (LIM-HD) transcription factor Apterous (Ap), which is known to regulate various developmental events, is required for both the consolidation and maintenance of LTM. Interestingly, Ap is involved in these 2 memory processes through distinct mechanisms in different neuronal subsets in the adult brain. Ap and its cofactor Chip (Chi) are indispensable for LTM maintenance in the Drosophila memory center, the mushroom bodies (MBs). On the other hand, Ap plays a crucial role in memory consolidation in a Chi-independent manner in pigment dispersing factor (Pdf)-containing large ventral–lateral clock neurons (l-LNvs) that modulate behavioral arousal and sleep. Since disrupted neurotransmission and electrical silencing in clock neurons impair memory consolidation, Ap is suggested to contribute to the stabilization of memory by ensuring the excitability of l-LNvs. Indeed, ex vivo imaging revealed that a reduced function of Ap, but not Chi, results in exaggerated Cl− responses to the inhibitory neurotransmitter gamma-aminobutyric acid (GABA) in l-LNvs, indicating that wild-type (WT) Ap maintains high l-LNv excitability by suppressing the GABA response. Consistently, enhancing the excitability of l-LNvs by knocking down GABAA receptors compensates for the impaired memory consolidation in ap null mutants. Overall, our results revealed unique dual functions of the developmental regulator Ap for LTM consolidation in clock neurons and LTM maintenance in MBs.

Photocatalysts are promising materials for solid-state antiviral coatings to protect against the spread of pandemic coronavirus disease (COVID-19). This paper reports that copper oxide nanoclusters grafted with titanium dioxide (CuxO/TiO2) inactivated the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus, including its Delta variant, even under dark condition, and further inactivated it under illumination with a white fluorescent bulb. To investigate its inactivation mechanism, the denaturation of spike proteins of SARS-CoV-2 was examined by sodium dodecyl sulphate–polyacrylamide gel electrophoresis (SDS-PAGE) and enzyme-linked immunosorbent assay (ELISA). In addition to spike proteins, fragmentation of ribonucleic acids in SARS-CoV-2 was investigated by real-time reverse transcription quantitative polymerase chain reaction (RT-qPCR). As a result, both spike proteins and RNAs in the SARS-CoV-2 virus were damaged by the CuxO/TiO2 photocatalyst even under dark condition and were further damaged under white fluorescent bulb illumination. Based on the present antiviral mechanism, the CuxO/TiO2 photocatalyst will be effective in inactivating other potential mutant strains of SARS-CoV-2. The CuxO/TiO2 photocatalyst can thus be used to reduce the infectious risk of COVID-19 in an indoor environment, where light illumination is turned on during the day and off during the night.