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Accumulating evidence revealed the role of tryptophan (TRP) metabolism, especially its kynurenine pathway (KP), in the communication along the gut-brain axis. However, the underlying characterization of such interaction was not precise. In the present study, the rat depression model was induced by chronic restraint stress (CRS). After depression behavior tests, seven segments (cortex, hippocampus, striatum, hypothalamus, serum, cecum, and colon) along the gut-brain axis were collected to characterize their KP metabolism. mRNA expression of IL-1β, IFN-γ, IL-10 and indoleamine 2,3-dioxygenase 1 (IDO1) enzyme revealed a general inflammatory response and region-specific activated IDO1 along the gut-brain axis. Determination of KP metabolites and enzymes displayed a general KP activation with region-specificity, especially in the hippocampus and colon, where the changes were more pronounced. KYN and 3-HK were increased dramatically along the gut-brain axis; hippocampal KA revealed a significant decrease while colonic KA showed a notable increase, evidenced by the same alternation trends of the corresponding enzymes. The expression of quinolinic acid phosphoribosyltransferase (QPRT), the crucial enzyme to produce NAD+ from QA, was significantly upregulated in the gut but not changed in the brain. Pearson's correlation analysis suggested that kynurenine (KYN), 3-hydroxycaninuric acid (3-HK), serotonin (5-HT), TRP and kynurenic acid (KA) significantly correlated with depressive behaviors in rats. Furthermore, western blot analysis on nod-like receptor protein 3/2 (NLRP3/NLRP2) inflammasome signaling displayed that NLRP3 and cleaved IL-1β/caspase-1 were significantly activated in the hippocampus and colon of CRS rats. However, NLRP2 was only activated in the hippocampus. These results revealed CRS induced inflammatory responses along the brain-gut axis of rats might be controlled through the NLRP3/NLRP2 inflammasome signaling pathway, which may be the underlying regulator for CRS-induced TRP-KYN metabolic changes. This study provides a new experimental background for developing stress-related health products. [Display omitted] • CRS induced KP activation with region-specificity along the gut-brain axis of depressed rats. • TRP-KYN metabolic changes along the gut-brain axis were significantly associated with depressive behaviors in rats. • NLRP3/NLRP2 inflammasome signaling pathway may be the underlying regulator. [ABSTRACT FROM AUTHOR]

Abstract Human telomerase is responsible for the maintenance of chromosome end structures and is a valuable biomarker for malignant growth. However, the accurate measurement of telomerase activity at the single-cell level has remained a great challenge. Here we develop a simple quantum dot (QD)-based electrochemical biosensor for stripping voltammetric detection of telomerase activity at the single-cell level. We designed a thiol-modified capture DNA which may be immobilized on the gold electrode by the gold-sulfur bond. The presence of telomerase enables the addition of the telomere repeats of (TTAGGG) n to the 3′ end of the primer, accompanied by the incorporation of abundant biotins in the extension product with the assistance of the biotin-tagged dATP. The subsequent hybridization of extension product with the capture DNA and the addition of streptavidin-coated QDs induce the assembly of large amounts of QDs onto the electrode via specific biotin-streptavidin binding. After the acidic dissolution of QDs, the released Cd (II) can be simply quantified by anodic stripping voltammetry (ASV). Due to the introduction of large amounts of QDs by telomerase-induced primer extension reaction and the synergistic signal amplification induced by the release of Cd (II) from the QDs, this biosensor can detect telomerase activity at the single-cell level without the involvement of any thermal cycling and extra enzymes for signal amplification. Moreover, this assay exhibits a large dynamic range over four orders of magnitude and it is very simple without the involvement of specific hairpin probe design and complicated labelling, holding great potential in point-of-need testing. Highlights • A simple quantum dot-based electrochemical biosensor is developed for sensitive detection of telomerase activity. • This biosensor can detect telomerase activity at the single-cell level. • This biosensor can be used for the discrimination of cancer cells from normal cells. • This biosensor can be used for the screening of telomerase inhibitors. [ABSTRACT FROM AUTHOR]

Even after decades of research, the preparation of mesoporous silica still depends on the sol–gel method. The major problem of sol–gel method is its infeasibility in industrial manufacturing. A large-scale preparation method is desired to meet the growing demand of mesoporous silica in multiple applications. A cost-effective and industrially feasible method was proposed to prepare mesoporous silica. The well-developed acid leaching technology was used as a novel pore forming method for treating coal fly ash. And mesoporous silica with specific surface area as high as 585.02 m 2 /g and pore volume of 0.54 cm 3 /g was successfully prepared under a control of reaction parameters. Reaction intensity was introduced as a new parameter to describe reaction conditions and help explain the variation of pore structure and shape prepared under different reaction conditions. This method is feasible in large-scale manufacturing of mesoporous silica and will satisfy the great demand for its wide applications. [ABSTRACT FROM AUTHOR]

Uracil-DNA glycosylase (UDG) is essential to the maintenance of genomic integrity due to its critical role in base excision repair pathway. However, existing UDG assays suffer from laborious procedures, poor specificity, and limited sensitivity. In this research, we construct a catalytic single-molecule Föster resonance energy transfer (FRET) biosensor for in vitro and in vivo biosensing of UDG activity. Target UDG can remove uracil base from the detection probe and cause the cleavage of detection probe by apurinic/apyrimidinic endonuclease (APE1), which exposes its toehold domain and initiates catalytic assembly of two fluorescently labeled hairpin probes via toehold-meditated strand displacement reaction (SDA) to generate abundant DNA duplexes with amplified FRET signal. In this assay, target UDG signal is amplified via enzyme-free catalytic reaction and the whole reaction may be completed in one step, which greatly simplifies the assay procedure, reduces the assay time, and facilitates the cellular imaging. This biosensor enables specific and sensitive measurement of UDG down to 0.00029 U/mL, and it is suitable for analyzing kinetic parameters, screening inhibitors, and even imaging endogenous UDG in live cells. Importantly, this biosensor can visually quantify various DNA repair enzymes by rationally altering DNA substrates. [ABSTRACT FROM AUTHOR]

Radix Polygalae, a commonly used traditional Chinese herb, has conventionally functioned in tranquilization and sedation, where anti-inflammation may be the underlying mechanism. Aim of the study : Chronic restraint stress (CRS), a risk factor for the etiology of intestinal disorders, was used in the present study to examine whether Radix Polygalae extract (RPE) could modulate colonic dysfunction in CRS rats. Wistar rats were exposed to 28-day CRS (6 h daily), and RPE (135 mg/kg and 270 mg/kg) was intragastrically administered 1 h before CRS. Subsequently, the gut microbiota was determined using metagenomic sequencing. Colonic proinflammatory interleukin-1β, −6, and −18 were assayed using qRT–PCR and ELISA. Tight junction proteins were quantified by qRT–PCR and western blotting (WB), and tryptophan metabolic enzymes and metabolites were determined using qRT–PCR and UFLC-QTRAP-5500/MS. Moreover, protein expression of colonic tight junction proteins, NF-κB-NLRP3 signaling involved in the underlying mechanism of RPE were detected by WB. RPE significantly decreased proinflammatory cytokines and reshaped the gut microbiota, especially the probiotics, including Lactobacillus and Bacteroides. Moreover, RPE could modulate the metabolite contents and enzyme expression associated with colonic tryptophan-kynurenine (TRP-KYN) metabolism and could increase tight junction protein expression in CRS rats. Furthermore, RPE inhibited the activation of NF-κB-NLRP3 signaling in the colon of CRS rats. RPE could modulate colonic inflammation, colonic microbiota, tight junction, TRP-KYN metabolism and NF-κB-NLRP3 signaling to reach a colonic balance of CRS rats. The present study helped us to better understand and appreciate the various beneficial effects of RPE. [Display omitted] • This study proved that Radix polygala could regulate intestinal dysfunction induced by CRS for the first time. • Based on brain-gut communication, the sedative and tranquilizing effects of Radix Polygalae may be mediated by intestinal flora. • NF-κB-NLRP3 signaling was involved in the modulating effect of RPE. [ABSTRACT FROM AUTHOR]

Acid leaching residue of coal gasification slag (ALR-CGS) is a by-product of the aluminum extraction process of CGS. Its amount increased with the industrialization of the CGS aluminum extraction process. Thanks to the high silica content of ALR-CGS, this research evaluated the synthesis of MCM-41 using this discarded material. Highly ordered MCM-41 with hexagonal shaped pore diameters of 2.91–3.65 nm was synthesized using ALR-CGS following a non-hydrothermal sol–gel method. The synthesized sample had a BET specific surface area of 1347 m 2 /g. ALR-CGS is a very competitive alternative silica source in the synthesis of MCM-41. [ABSTRACT FROM AUTHOR]

A straightforward and economical synthetic route for the preparation of cholesterol was developed from plant origin bisnoralcohol. [Display omitted] • Plant-derived cholesterol was synthesized from bisnoralcohol. • This promising route for production of cholesterol has a high overall yield. • The epicholesteorl and cholestanol were also synthesized. Currently, the market demand of the non-animal-derived cholesterol is increasing. A novel synthetic route of producing cholesterol was developed through multiple reactions from plant-sourced and commercially available bisnoralcohol (BA). The key reaction conditions, including solvents, reaction temperatures, bases and reducing agents of the route were investigated and optimized. In this straightforward synthetic pathway of cholesterol, most of the reaction steps possess high conversions with average yields of 94%, and the overall yield is up to 74% (5 steps) from the BA. The epicholesterol and were also synthesized. This promising route offers economical and efficient strategies for potential large-scale production of plant-derived cholesterol. [ABSTRACT FROM AUTHOR]

Chronic stressors represented risk factors for the etiology or exacerbation of several gastrointestinal diseases. The goal of the present study was to examine whether chronic restraint stress (CRS) could initiate and aggravate colonic inflammation, integrity damage and metabolic disturbance of rats. Firstly, increased inflammatory cytokines (interferon-γ (IFN-γ), tumor necrosis factor-α(TNF-α) and interleukin-10(IL-10)) and decreased tight junction (TJ) proteins (occludin and zonula occludins-1 (ZO-1)) in rat colon were observed. Secondly, untargeted metabolomics based on ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass (UPLC-Q-TOF/MS) revealed that TRP metabolism was the most prominently affected. Thirdly, quantification of TRP and its metabolites via prominence ultrafast liquid chromatography coupled with a QTRAP 5500 mass (UFLC-QTRAP-5500/MS) showed that TRP, kynurenine (KYN), kynurenic acid (KA) and 3-hydroxykynurenine (3−HK) were significantly increased. At the same time, 5-hydroxytryptamine (5-HT) was unchanged and 5-hydroxyindolacetic acid (5-HIAA) was significantly decreased in the colon of CRS rats. Besides, TRP metabolic enzyme changes were with the same trends as the corresponding metabolites. Thus, our data showed that CRS could initiate colonic inflammation, integrity damage and colonic metabolism disturbance, especially TRP-KYN metabolism pathway of rats, which may provide an experimental background for future research on stress-related gastrointestinal dysfunction. Chronic exposure to psychological stress could induce metabolic imbalance of the body, and stressful life events were intimately correlated with frequent relapses in patients with intestinal disorders. The present study showed that chronic restraint stress (CRS) could initiate and aggravate colonic inflammation, integrity damage and metabolic disturbance, especially tryptophan-kynurenine metabolism of rats. Tryptophan-kynurenine pathway may be involved in the initiation and development of diseases induced by chronic stress. This research may shed light on future research on stress-related gastrointestinal dysfunction. [Display omitted] • Chronic restraint stress (CRS) initiated colonic inflammation, integrity damage and metabolic disturbance of rats. • Metabolomic analysis revealed that CRS induced alteration in colonic TRP-kynurenine (KYN) metabolism of rats. • TRP-KYN metabolism pathway may play an important role in stress-related gastrointestinal dysfunction. [ABSTRACT FROM AUTHOR]

Recent studies have shown that adding active oxygen scavengers to edible coatings can maintain the storage quality and commercial value of postharvest fruit. In this research, the effect of a chitosan-based edible coating containing ascorbic acid (CH, 1% + AA, 1%) on Annona squamosa at storage conditions of 15 ± 1 °C was investigated for twelve days. The results showed that CH+AA could delay the decrease of firmness, appearance deterioration, weight loss, and accumulation of MDA content during the storage of Annona squamosa. The CH+AA composite coating also delayed the deterioration of quality by maintaining high titratable acidity, moisture content and antioxidant enzyme activities. In addition, CH+AA inhibited the softening of fruit by regulating the activities of cell wall degrading enzymes and their gene expression levels. In conclusion, the CH+AA composite coating can keep the quality of Annona squamosa stored after harvesting. [Display omitted] • CH+AA coating was better than that of single chitosan coating. • CH+AA coating can significantly improve the physicochemical properties of Annona squamosa. • CH+AA coating was significant influence in gene expression. [ABSTRACT FROM AUTHOR]

Tryptophan (TRP) metabolism could occur both peripherally and centrally, which plays an essential role in brain and gastrointestinal disorders. The participation of TRP metabolism in the bidirectional brain-gut interactions is of value to better understand the mechanism of the pathophysiology of depression. To compare the difference between peripheral and cerebral TRP metabolism in depression, the chronic unpredicted mild stress (CUMS) was used to induce depressive-like syndrome in rats. After the rats were subjected to CUMS for five weeks, TRP and its metabolites were determined by prominence ultrafast liquid chromatography (UFLC) coupled with a QTRAP 5500 mass spectrometer (UFLC-QTRAP-5500/MS), and the expression of TRP metabolic enzymes were examined by Real-time quantitative PCR (qRT-PCR). CUMS induced TRP metabolism abnormalities in the colon, cortex and hippocampus of rats. There were regional metabolism differences, but the common points were the upregulation of indoleamine-2,3-dioxygenase 1 (IDO1) and the increased contents of Kynurenine (KYN), which suggested that KYN pathway (KP) was more favored than the serotonin (5-HT) pathway in the TRP metabolism under CUMS in the three regions studied. More importantly, KYN was preferentially metabolized into neurotoxic 3-hydroxycaninuric acid (3-HK) branch in the cortex and hippocampus while Kynurenic acid (KA) branch in the colon under CUMS. Interestingly, according to the Pearson's correlation coefficients, there may be correlations between the colonic KYN and cerebral 3-HK and KA. It advances our understanding of the role of TRP metabolism in gut-brain communication and provides new research ideas and methods for depression. Image 1 • Tryptophan (TRP) metabolism plays an essential role in brain and gastrointestinal disorders. • Region-specific differences of TRP metabolism. • Correlations between colonic Kynurenine (KYN) and cerebral KYN,3-hydroxycaninuric acid (3-HK) and Kynurenic acid (KA). [ABSTRACT FROM AUTHOR]

Single-molecule fluorescence resonance energy transfer (smFRET) requires significant spectral overlap between the donor emission and the acceptor absorption, and its efficiency is strongly dependent on the donor-acceptor distance. Consequently, smFRET has the capability to study molecular interactions of biomolecules with sub-nanometer resolution in a homogeneous manner without the involvement of any separation steps. The smFRET has significant advantages of high signal-to-noise ratio, low sample consumption, and homogeneous assay, providing a new approach to detect low-abundant biomolecules with extremely high sensitivity. In this review, we summarize the strategies for improving smFRET efficiency and the applications of smFRET in sensitive detection of DNAs, microRNAs, enzymes, and in situ imaging of single-nucleotide mutation. Moreover, we provide new insight into the challenges and future perspectives of smFRET. • Single-molecule fluorescence resonance energy transfer (smFRET) provides a new approach to detect low-abundant biomolecules. • We summarize the strategies for improving smFRET efficiency. • We review the applications of smFRET in sensitive detection of DNAs, microRNAs and enzymes. • We provide new insight into the challenges and future perspectives of smFRET. [ABSTRACT FROM AUTHOR]

Abstract We develop for the first time a new electrochemical biosensor for signal-on detection of T4 polynucleotide kinase (PNK) based on the enhanced quasi-reversible redox signal of prussian blue generated by self-sacrificial label of iron metal-organic framework (FeMOF). The DNA hairpin probe modified with FeMOF@AuNPs at the 3'-thiol end acts as the substrate of PNK. The presence of PNK enables the 5'-phosphorylation of hairpin probe, which may subsequently function as the substrate of lambda exonuclease. Lambda exonuclease removes the 5' mononucleotides from the stem, unfolding the hairpin structure and releasing the single-stranded DNA (ssDNA). The resultant FeMOF@AuNP-modified ssDNA may specifically hybridize with the capture probe to form the double-strand DNA (dsDNA) duplex, enabling the immobilization of FeMOF on the electrode surface. The reaction of Fe3+ in the MOF with K 4 Fe(CN) 6 leads to the formation of prussian blue on the electrode surface and consequently the generation of a high electrochemical signal. This assay is very simple without the involvement of the pre-synthesized prussian blue which is unstable in neutral buffer, and the self-sacrificial label of FeMOF can achieve great signal amplification without the involvement of any extra functional materials. Due to the introduction of self-sacrificial label of FeMOF and the formation of prussian blue nanolayers with good quasi-reversible cyclic voltammetric electrochemical activity, this biosensor exhibits high sensitivity and a large dynamic range. Moreover, this biosensor can be used to screen the PNK inhibitors, holding great potential in disease diagnosis and drug discovery. Highlights • We develop a new electrochemical biosensor for signal-on detection of T4 polynucleotide kinase (PNK). • This electrochemical biosensor is based on the enhanced quasi-reversible redox signal of prussian blue generated by self-sacrificial label of iron metal-organic framework (FeMOF). • This assay is very simple without the involvement of the pre-synthesized prussian blue which is unstable in neutral buffer. • The self-sacrificial label of FeMOF can achieve great signal amplification without the involvement of any extra functional materials. [ABSTRACT FROM AUTHOR]

• Innovates miRNA detection with cholesterol-enhanced 3D DNA Walker, enhancing precision. • Uses micelle structure for nuclease protection, cutting false positives in samples. • Allows cancer cell autonomous miRNA imaging, no need for external cofactors. • Enables precise cancer subtype identification via multiple miRNAs, boosting accuracy. • Advances molecular diagnostics, key for early detection and personalized medicine. Achieving reliable miRNA detection and imaging remains a critical and formidable challenge. To address this challenge, we developed a three-dimensional (3D) DNA walker nanoprobe (DWN), derived from a multifunctional molecular beacon with a lipidic moiety. This innovative structure employs a cholesterol-conjugated multifunctional molecular beacon (Chol-MMB) assembled through hydrophobic interactions, thereby bypassing the cumbersome and inefficient process of immobilizing DNA strands onto rigid surfaces. Once the walker nanoprobe enters cells, the binding between the target miRNA and the nanoprobe triggers an intermolecular polymerization process, leading to a conformational change in DWN. This change liberates a walking strand, initiating the walking reaction. As a result, the 3D DNA walker nanoprobe illuminates the fluorophore, enabling precise quantitative analysis. The efficacy of the DWN was demonstrated by the limit of detection of 0.326 fmol for miR-21 with a reaction duration of 1 h. In addition, this strategy effectively differentiates various cells based on the specific miRNA. Further refinement of this method will lead to an efficacious miRNA-based platform for cell typing and liquid biopsy. [ABSTRACT FROM AUTHOR]

DNA glycosylase assumes a pivotal role in the preservation of genome integrity by recognizing and excising damaged bases. Herein, we develop a single primer/self-template-powered cascade rolling circle amplification (RCA) and apurinic/apyrimidinic endonuclease (APE1)-mediated signal amplification for simultaneous detection of human alkyladenine DNA glycosylase (hAAG) and uracil DNA glycosylase (UDG). The uniqueness of this approach lies in the use of custom-designed hairpin probes to establish a prerequisite for RCA: the conformational change of hairpin probe to circular template, which effectively suppress undesired non-specific amplification. We design two hairpin probes featuring elongated stem structure and 3′-phosphate (3′-PO 4) modifications. The stems of hairpin probes are modified with glycosylase substrates and BER process can cleave hairpin probes, resulting in the generation of single-stranded DNAs (ssDNAs) with 3′-hydroxyl (3′-OH) ends. These ssDNAs can function as padlock probes to form circular template upon ligation by ligase. Ultimately, the self-template-initiated RCA and APE1-mediated signal amplification cascade occurs, generating a substantial number of free Cy3 and Cy5 fluorophores that can be simply visualized by single-molecule fluorescence detection. This method demonstrates excellent specificity and sensitivity, with a limit of detection (LOD) of 3.42 × 10-12 U/μL for hAAG and 2.41 × 10-12 U/μL for UDG. This method also can be used for screening of potential inhibitor and kinetic parameter measurement. Most importantly, this method enables accurate profiling of glycosylases expression levels in various cancer cell lines and detection of glycosylase activities at the single-cell level, offering a bright future in cancer detection, medical research, and precision medicine. • Simultaneous detection of multiple glycosylases at ultra-low concentrations. • Conformation-switchable hairpin probes and self-templated amplification reduce non-specific amplification. • One primer probe can simultaneously trigger two isothermal amplifications. • Accurate assessment of DNA glycosylase expression in different cancer cell lines. [ABSTRACT FROM AUTHOR]

Hybridization chain reaction (HCR) based enzyme-free amplification techniques have recently been developed for the visualization of intracellular messenger RNA (mRNA). However, the slow kinetics and potential interference with the intricate biological environments hinder its application in the clinic and in vivo. Herein, we designed a nanofirecracker probe-based strategy using i ntramolecular h ybridization c hain r eaction (IHCR) amplifier for rapid, efficient, sensitive, specific detection and imaging of survivin mRNA both in vitro and vivo. Two probes, HP1 and HP2, in IHCR were simultaneously incorporated into a DNA nanowire scaffolds to bring HP1 and HP2 to close proximity on the assembled nanowire scaffolds. Empowered by the DNA nanowire scaffolds and spatial confinement effect, the nanofirecracker probe-based IHCR sensing system exhibited improved biostability, accelerated reaction kinetics, and enhanced signal amplification. This new strategy has been successfully applied to imaging mRNA in both cultured cells and in mice. Importantly, this novel sensing method was capable of detecting survivin mRNA in clinical blood samples from subjects with colorectal cancer. Thus, this novel nanofirecracker probe-based IHCR strategy holds great potential in advancing both biomedical research and in molecular diagnostics. [ABSTRACT FROM AUTHOR]

DNA repair enzymes are responsible for the repair of DNA lesions and are important disease biomarkers. Herein, we construct a target-triggered DNAzyme motor for electrochemical detection of multiple DNA glycosylases based on the DNAzyme motor-driven encoding of different electrochemical molecules. This assay involves two hairpin probes for sensing uracil DNA glycosylase (UDG) and human alkyladenine DNA glycosylase (hAAG), a AuNPs@locked DNAzyme motor which contains the locking strands and the Mg2+/Pb2+ DNAzyme strands, and a magnetic bead track which contains MB/Fc-labelled Mg2+/Pb2+ substrate strands. When UDG and hAAG are present, they can cleave the corresponding hairpin DNA probes to release two single-stranded DNAs (ssDNAs) which can hybridize with the locking strands to induce the liberation of Mg2+/Pb2+ DNAzyme strands from the AuNPs@DNAzyme motor. The subsequent hybridization of Mg2+/Pb2+ DNAzyme strands with their corresponding substrate strands results in the cleavage of Mg2+/Pb2+ substrate strands and the simultaneous release of MB/Fc-labelled ssDNAs from magnetic bead. The released MB/Fc labels can be electrochemically detected for accurate quantification of UDG/hAAG. This target-triggered DNAzyme motor exhibits high sensitivity and good specificity with the capability of simultaneously measuring multiple DNA glycosylases in HeLa cells and screening the potential inhibitors. • We develop a target-triggered DNAzyme motor for electrochemical detection of multiple DNA glycosylases. • The electrochemical signals result from the DNAzyme motor-driven encoding of different electrochemical molecules. • This DNAzyme motor exhibits high sensitivity and good specificity. • This DNAzyme motor can simultaneously measure multiple DNA glycosylases in HeLa cells. • This DNAzyme motor can be applied for the screening of potential inhibitors. [ABSTRACT FROM AUTHOR]

Carbon monoxide (CO) releasing molecule (CORM)-3, a water-soluble CORM, has protective effects against inflammatory and ischemia/reperfusion injury. We determined the effect of CORM-3 against neuronal pyroptosis in a model of hemorrhagic shock and resuscitation (HSR) in rats via mitochondrial regulation. Rats were treated with CORM-3 (4 mg/kg) in vitro after HSR. We measured cortical CO content 3–24 h after HSR; assessed neuronal pyroptosis, mitochondrial morphology, ROS production, and mitochondrial membrane potential at 12 h after HSR; and evaluated brain magnetic resonance imaging at 24 h after HSR and learning ability 30 days after HSR. We also measured soluble guanylate-cyclase (sGC)-cyclic guanosine monophosphate (cGMP) signaling pathway activity using a blocker of sGC, NS2028, and 125I-cGMP assay. Among rats that underwent HSR, CORM-3-treated rats had more CO in the cortical tissue than sham- and iCORM-3-treated rats. CORM-3-treated rats had significantly less neuronal pyroptosis in the cortical tissue; higher sGC activity and cGMP content; lower ROS production; better mitochondrial morphology, function, and membrane potential; and enhanced learning/memory ability than HSR-treated rats. However, these neuroprotective effects of CORM-3 were partially inhibited by NS2028. CORM-3 may alleviate neuronal pyroptosis and improve neurological recovery in HSR through mitochondrial regulation mediated by the sGC–cGMP pathway. Thus, CO administration could be a promising therapeutic strategy for hemorrhagic shock. A proposed diagram tying together the observations involved in CORM-3-induced neuroprotection against HSR. HSR increased neuronal pyroptosis, which might be associated with up-regulation of ROS. CORM-3 not only significantly reduced these neuronal pyroptosis, but also improved long-term learning ability and T2-weighted MRI, which might be associated with inhibition of mitochondrial dysfunction through regulating activity in sGC-cGMP signal pathway, whereas NS2028, a blocker of sGC, could partially inhibit these neuroprotective effects. Image 1 • Hemorrhage shock and resuscitation (HSR) induced cortical neuronal pyroptosis, mitochondrial injury, and decrased learning ability. • CORM-3 administration after resuscitation provided neuroprotection for HSR, and improved learning ability. • The neuroprotective mechanism of CROM-3 against HSR injury could be associated with sGC–cGMP pathway. [ABSTRACT FROM AUTHOR]

Abstract We demonstrate for the first time the development of a universal DNAzyme-based bioluminescent sensor for label-free detection of various biomolecules including DNAzyme and DNA. The presence of DNAzyme may induce the cyclic cleavage of riboadenosine (rA)-containing substrates, and the subsequent digestion of the cleaved substrates by exonuclease III (Exo III) releases abundant AMPs to initiate cyclic AMP pyrophosphorylation-ATP depyrophosphorylation for the generation of an enhanced bioluminescence signal. This sensor can real-time monitor the DNAzyme activity with a detection limit of 3.16 × 10−12 M. Moreover, the DNAzyme may be divided into two subunits for sensitive detection of target DNA. In the presence of target DNA, the two separated subunits may assemble into an active DNAzyme which can catalyze the cyclic cleavage of substrates and initiate the digestion of cleaved substrates by Exo III for the generation of an enhanced bioluminescence signal. This sensor can sensitively detect target DNA with a detection limit of 3.31 × 10−12 M. Importantly, this bioluminescent sensor can achieve a zero-background signal, and its output signal originates from the release of AMP for the generation of self-illuminating light emission without the requirement of either the external labels or the reporting reagents. Graphical abstract We develop a universal DNAzyme-based bioluminescent sensor for label-free detection of various biomolecules including DNAzyme and DNA. Image 1 Highlights • We develop a universal DNAzyme-based bioluminescent sensor for label-free detection of various biomolecules. • DNAzyme can cleave its substrate and release AMPs for the generation of self-illuminating light emission. • This sensor does not require either external labels or the reporting reagents. • This sensor can generate an enhanced bioluminescence signal with zero background. [ABSTRACT FROM AUTHOR]

Introduction Myocardial ischemia-reperfusion (I/R) injury affects millions of people worldwide and has a very high mortality rate. Since microRNA-497 (miR-497) has been found to be related with cardiomyocyte apoptosis, this study aimed to explore the effect of miR-497 by targeting Mfn2 in a mouse model of myocardial ischemia-reperfusion (I/R) injury. Materials BALB/c mice were modeled with I/R and some were injected with miR-497 agomir before I/R to observe whether miR-497 alleviates the injury that occurs as a result of I/R. Bioinformatics website and dual-luciferase reporter gene assay were employed in order to detect the relations between miR-497 and Mfn2 gene. Next, cells were extracted to be transfected with different mimic, inhibitor and siRNAs to further explore how miR-497 acts to I/R. Western blot analysis and reverse transcription quantitative polymerase chain reaction (RT-qPCR) were conducted to measure expressions of miR-497, Mfn2, Fas, Bcl-2, Bax and Caspase-3 in myocardial tissues and cardiomyocytes after transfection. CCK-8 assay and flow cytometry were used to determine proliferation, cell cycle distribution and apoptosis of cardiomyocytes in each group after transfection. Results Mice with I/R had myocardial dysfunction but before the injection with miR-497 agomir, the impairment was alleviated. Mfn2 was verified as the target gene of miR-497. The inhibition of miR-497 in turn inhibits Mfn2 expressione and cardiomyocyte apoptosis. The overexpression of miR-497 and Mfn2 gene silencing can lead to the promotion of proliferation capability of mice cardiomyocytes in vitro. Overexpressed miR-497 and Mfn2 gene silencing can also facilitate cell cycle entry and inhibit the apoptosis cardiomyocytes of mice in vitro. Conclusion The present study provided strong evidence that miR-497 promotes proliferation and inhibits apoptosis of cardiomyocytes by downregulating the expression of Mfn2 in a mouse model of myocardial I/R injury. [ABSTRACT FROM AUTHOR]

• SPC can be a good feed ingredient as swimming crab can tolerate up to 75% replacement. • Replacement of dietary fish meal with SPC will inhibit TOR pathway in hepatopancreas. • 51.49% replacement level with SPC is recommended for better PER. A 56-day feeding trial was conducted to evaluate the potential use of soy protein concentrate (SPC) as a partial replacement of fish meal in swimming crab Portunus trituberculatus. Four isonitrogenous and isolipidic diets (450 g/kg protein and 80 g/kg lipid) were formulated to contain graded levels of SPC, and fish meal was replaced with SPC at 25%, 50% and 75% level (SPC25, SPC50 and SPC75, respectively). The control diet (SPC0) contained fish meal, soybean meal and krill meal as the main protein sources. Lysine and methionine were added into SPC replacement diets to maintain the same concentrations as the control diet. Each diet was randomly assigned to triplicate groups of 45 juvenile swimming crabs (5.00 ± 0.23 g / crab) that were stocked in the rectangle plastic baskets. The results indicated that the weight gain (WG), special growth rate (SGR), feed efficiency (FE) and daily feed intake (DFI) were not significantly influenced by the dietary replacement of fish meal with SPC (P > 0.05). Crabs fed the SPC75 diet had lower protein efficiency ratio (PER) and molting frequencey (MF) than those fed the SPC50 diet(P < 0.05). The proximate compositions in whole body and muscle were not significantly influenced by the replacement of fish meal with SPC (P > 0.05), however, there was significant difference in the hepatopancreas moisture content (P < 0.05), and crabs fed the SPC0 diet had the highest lipid in hepatopancreas among all treatments (P < 0.05). Moreover, the essential amino acid (EAA), non-essential amino acid (NEAA) and total amino acid (TAA) contents of muscle significantly increased with the dietary replacement of fish meal with SPC levels increasing from 0 to 75% (P < 0.05). No significant differences in hemolymph enzyme activities and characteristics were observed among all treatments (P > 0.05). Crabs fed the SPC0 diet had higher amylase and lipase activities in hepatopancreas than those fed other diets. The hepatopancreas trypsin activity was not significantly influenced by the replacement of fish meal with SPC (P > 0.05). The hepatopancreas alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities increased when the dietary SPC levels increased from 0 to 25%, and then decreased significantly with the further increase of SPC replacement levels (P < 0.05). The relative expression of genes in target of rapamycin (TOR) pathway, crabs fed the SPC0 diet had higher relative expressions of tor, akt, s6k1, s6, 4ebp1, eif4e1a, eif4e2 and eif4e3 genes in hepatopancreas than those fed other diets (P < 0.05), moreover, there were no significant differences in gene expressions of TOR pathway among crabs fed the SPC25, SPC50 and SPC75 diets (P > 0.05). Based on the two slope broken-line regression analysis of PER against the dietary fish meal replacement with SPC levels, the optimum dietary replacement of fish meal with SPC was determined to be 51.49% for juvenile swimming crab. [ABSTRACT FROM AUTHOR]

An 8-week feeding trial was conducted to evaluate the effects of different dietary arachidonic acid (ARA) levels on growth performance, fatty acid composition, hepatic intermediary metabolism and antioxidant responses for juvenile yellow catfish. An ARA-enriched oil was supplemented into the basal diet to formulate six iso-nitrogenous and iso-energetic practical diets containing 0.03% (the control diet), 0.30%, 0.60%, 0.90%, 1.20% and 1.50% of dry weight. Dietary ARA levels were 0.39%, 2.47%, 4.96%, 7.49%, 9.79% and 12.64% total fatty acids, respectively. Triplicate groups of 20 fish (average initial weight is about 1.55 ± 0.01 g) were fed to apparent satiation twice daily. The results indicated that fish fed the diets containing 4.96% and 7.49% ARA of total fatty acids have higher final body weight and percent weight gain (PWG) than those fed the other diets. Survival, feed conversion ratio, hepatosomatic index and viscerosomatic index were not significantly influenced by the dietary ARA levels. Fatty acid compositions both in liver and muscle reflected closely those of fatty acid profiles in diets, ARA proportion in liver and muscle significantly increased with dietary ARA levels increasing from 0.39% to 12.64% of total fatty acids, while, EPA proportion in liver significantly decreased with increase of dietary ARA levels. Fish fed the control diet had the highest aspartate aminotransferase (AST) and glucose content in serum among all treatments, and fish fed the 9.79% and 12.64% ARA of total fatty acids had higher malondialdehyde (MDA) content in liver than those fed the other diets. However, the activities of total superoxide dismutase (T-SOD), glutathione peroxidase (GSH-PX) and catalase (CAT) in liver were not significantly influenced by dietary ARA levels. The relative gene expression of accα , g6pd , 6pgd and evovl5 in liver down-regulated significantly with the dietary ARA levels increasing from 0.39% to 12.64% of total fatty acids. The relative gene expression of atgl and hslb in liver down-regulated significantly with the dietary ARA levels increasing from 0.39% to 7.49% of total fatty acids, and then up-regulated as dietary ARA levels increasing from 9.79% to 12.64%. However, relative gene expression of cpt1a and ppara in liver are down-regulated in ARA supplemental groups. These results suggested that dietary moderate ARA levels (4.96% and 7.49% of total fatty acids) could improve growth performance and antioxidant response, and up-regulate or down-regulate relative expression levels of some lipid metabolism-related gene in liver. Two slope broken-line regression analysis of PWG against dietary ARA levels indicated that optimal dietary ARA requirement for juvenile yellow catfish was 6.45% of total fatty acids. [ABSTRACT FROM AUTHOR]

HMG-CoA reductase (HMGCR) is the rate-limiting enzyme in cholesterol de novo biosynthesis and its degradation may bring therapeutic benefits for the treatment of cardiovascular disease (CVD) and nonalcoholic steatohepatitis (NASH). Before, we disclosed compound HMG499 as a potent HMGCR degrader, which could be a promising agent for treating CVD, however its side-effect of promoting cholesterol accumulation in cells should be eliminated before progression. Herein, a series of novel heterocyclic ring-fused analogs of HMG499 were synthesized and investigated for their activities of stimulating HMGCR degradation using a HMGCR (TM1-8)-GFP reporting system. Among them, the most active compound 29 (QH536) showed an EC 50 of 0.22 μΜ in promoting HMGCR degradation, which was about 2 times more potent than HMG499 (EC 50 = 0.43 μM). Interestingly, 29 was different from HMG499, it had no side-effect of inducing cholesterol accumulation in cells. Mechanistic studies disclosed that 29 could significantly decrease statin-induced accumulation of HMGCR protein via ubiquitination and degradation of HMGCR through ubiquitin-proteasome pathway and inhibit the cholesterol biosynthesis in cells. Therefore, these heterocyclic ring-fused analogs could be used as promising leads for the development of new types of agents against CVD. Furthermore, 29 also lowered cholesterol levels and suppressed TGFβ1-induced proliferation of LX-2 hepatic stellate cells in a dose-dependent manner. In particular, 29 not only decreased the NASH associated fibrotic mRNA and protein expression of α-SMA, COL1A1, TIMP1 and TGFβ1 but also suppressed cholesterol levels and inflammatory genes of TNF-α, IL-6 an IL-1β in RAW264.7 macrophage cells, indicating that 29 may bring therapeutic benefit to treat NASH. A series of heterocyclic ring-fused analogs of HMG499 were synthesized and their activities of promoting HMG-CoA reductase degradation and side-effects of inducing cholesterol accumulation in cells were evaluated. [Display omitted] • A series of novel heterocyclic ring-fused analogs of HMG499 were synthesized. • The activities of promoting HMGCR degradation of these analogs were evaluated. • Compound 29 is the most potent HMGCR degrader. • Compound 29 possessed no side-effect of inducing cholesterol accumulation. [ABSTRACT FROM AUTHOR]

Abstract: (−)-Epigallocatechin-3-gallate (EGCG), the main active component of green tea, is commonly known for its beneficial properties at low doses. On the other hand, little is known about the adverse effects of EGCG. Voltage-gated sodium channel (VGSC) is responsible for both initiation and propagation of action potentials of the neurons in the hippocampus and throughout the central nervous system (CNS). In this study, the effects of EGCG on voltage-gated sodium channel currents (I Na) were investigated in rat primary cultures of hippocampal CA1 neurons via the conventional whole-cell patch-clamp technique. We found that I Na was not affected by EGCG at the concentration of 0.1μM, but was completely blocked by EGCG at the concentration of 400μM and higher, and EGCG reduced the amplitudes of I Na in a concentration-dependent manner in the range of 0.1–400μM. Furthermore, our results also showed that at the concentration of 100μM, EGCG was known to have the following performances: (1) it decreased the activation threshold and the voltage at which the maximum I Na current was evoked, caused negative shifts of I Na steady-state activation curve. (2) It enlarged I Na tail-currents. (3) It induced a left shift of the steady-state inactivation. (4) It reduced fraction of available sodium channels. (5) It delayed the activation of I Na in a voltage-dependent manner. (6) It prolonged the time course of the fast inactivation of sodium channels. (7) It accelerated the activity-dependent attenuation of I Na. On the basis of these findings, we propose that EGCG could impair certain physiological functions of VGSCs, which may contribute, directly or indirectly, to EGCG''s effects in CNS. [Copyright &y& Elsevier]

A straightforward and economical synthetic route for the preparation of ursodeoxycholic acid was developed from plant-source bisnoralcohol. • A facile route of producing ursodeoxycholic acid from plant-source BA is provided. • This promising route for production of ursodeoxycholic acid has a high yield. • This route of-fers a method for po-ten-tial large-scale pro-duc-tion of UDCA. A novel synthetic route of producing ursodeoxycholic acid (UDCA) was developed through multiple reactions from cheap and commercially available bisnoralcohol (BA). The key reaction conditions, including solvents, bases and reaction temperatures of the route were investigated and optimized. In the straightforward route for preparation of UDCA, most of the reaction steps have high conversions with average yields of 91%, and overall yield up to 59% (6 steps) from the plant-source BA. Especially in the last step of reduction and hydrolysis, there are five functional groups converted with calcd 97% per conversion in one-pot reaction. This promising route offers economical and efficient strategies for potential large-scale production of UDCA. [ABSTRACT FROM AUTHOR]

Cajaninstilbene acid (CSA), a bioactive constituent isolated from pigeon pea leaves, exhibited neuroprotective activities in previous studies. The present study aims to evaluate the antidepressant effects of CSA by using behavioral despair models of tail suspension test (TST) and forced swimming test (FST), and a chronic unpredictable mild stress (CUMS) model. CSA (30 or 60 mg/kg), intragastrically administrated for 7 days, could significantly reduce the immobility time of mice in TST and FST. CSA treatment (15 or 30 mg/kg) significantly reversed the depressive-like behavioral changes of mice induced by 3 or 6 weeks CUMS that caused the decrease of sucrose preference, the increase of latency to feed in the novelty-suppressed feeding test, and the increase of immobility time in TST of mice. Furthermore, the related mechanisms of the effect were explored by accessing the metabolite levels of kynurenine pathway of tryptophan metabolism and the expression of some related proteins in cerebral cortex of CUMS mice. Our results showed that the kynurenine pathway was upregulated after CUMS, while the alteration could be significantly reversed by CSA. CSA also reversed the CUMS-induced decrease in the levels of BDNF, PSD-95, p-Akt/Akt and p-mTOR/mTOR. Therefore, the antidepressant-like effects of CSA might be achieved through regulating tryptophan metabolism, promoting BDNF and PSD-95 expression, and activating Akt/mTOR pathway in the cerebral cortex. Unlabelled Image [ABSTRACT FROM AUTHOR]