N4 -Allyldeoxycytidine: A New DNA Tag with Chemical Sequencing Power for Pinpointing Labelling Sites, Mapping Epigenetic Markers, and In Situ Imaging.

DNA tagging with base analogues has found numerous applications. To precisely record the DNA labelling information, it would be highly beneficial to develop chemical sequencing tags that can be encoded into DNA as regular bases and decoded as mutant bases following a mild, efficient and bioorthogonal chemical treatment. Here we reported such a DNA tag, N4 -allyldeoxycytidine (a4 dC), for labeling and identifying DNA by in vitro assays. The iodination of a4 dC led to fast and complete formation of 3, N4 -cyclized deoxycytidine, which induced base misincorporation during DNA replication and thus could be located at single base resolution. We explored the applications of a4 dC in pinpointing DNA labelling sites at single base resolution, mapping epigenetic marker N4 -methyldeoxycytidine, and imaging nucleic acids in situ. In addition, mammalian cellular DNA could be metabolically labelled with a4 dC. Our study sheds light on the design of next generation DNA tags with chemical sequencing power.

A metabolic labeling method detects m6A transcriptome-wide at single base resolution.

Transcriptome-wide mapping of N6-methyladenosine (m6A) at base resolution remains an issue, impeding our understanding of m6A roles at the nucleotide level. Here, we report a metabolic labeling method to detect mRNA m6A transcriptome-wide at base resolution, called 'm6A-label-seq'. Human and mouse cells could be fed with a methionine analog, Se-allyl-L-selenohomocysteine, which substitutes the methyl group on the enzyme cofactor SAM with the allyl. Cellular RNAs could therefore be metabolically modified with N6-allyladenosine (a6A) at supposed m6A-generating adenosine sites. We pinpointed the mRNA a6A locations based on iodination-induced misincorporation at the opposite site in complementary DNA during reverse transcription. We identified a few thousand mRNA m6A sites in human HeLa, HEK293T and mouse H2.35 cells, carried out a parallel comparison of m6A-label-seq with available m6A sequencing methods, and validated selected sites by an orthogonal method. This method offers advantages in detecting clustered m6A sites and holds promise to locate nuclear nascent RNA m6A modifications.

A Mutation-Based Method for Pinpointing a DNA N6 -Methyladenine Methyltransferase Modification Site at Single Base Resolution.

DNA N6 -methyladenine (6mA) has recently received notable attention due to an increased finding of its functional roles in higher eukaryotes. Here we report an enzyme-assisted chemical labeling method to pinpoint the DNA 6mA methyltransferase (MTase) substrate modification site at single base resolution. A designed allyl-substituted MTase cofactor was applied in the catalytic transfer reaction, and the allyl group was installed to the N6 -position of adenine within a specific DNA sequence to form N6 -allyladenine (6aA). The iodination of 6aA allyl group induced the formation of 1, N6 -cyclized adenine which caused mutations during DNA replication by a polymerase. Thus the modification site could be precisely detected by a mutation signal. We synthesized 6aA deoxynucleoside and deoxynucleotide model compounds and a 6aA-containing DNA probe, and screened nine DNA polymerases to define an optimal system capable of detecting the substrate modification site of a DNA 6mA MTase at single-base resolution.

Cigarette smoking and schizophrenia: Mendelian randomisation study.

BACKGROUND: The link between schizophrenia and cigarette smoking has been well established through observational studies. However, the cause-effect relationship remains unclear. AIMS: We conducted Mendelian randomisation analyses to assess any causal relationship between genetic variants related to four smoking-related traits and the risk of schizophrenia. METHOD: We performed a two-sample Mendelian randomisation using summary statistics from genome-wide association studies (GWAS) of smoking-related traits and schizophrenia (7711 cases, 18 327 controls) in East Asian populations. Single nucleotide polymorphisms (SNPs) correlated with smoking behaviours (smoking initiation, smoking cessation, age at smoking initiation and quantity of smoking) were investigated in relation to schizophrenia using the inverse-variance weighted (IVW) method. Further sensitivity analyses, including Mendelian randomisation-Egger (MR-Egger), weighted median estimates and leave-one-out analysis, were used to test the consistency of the results. RESULTS: The associated SNPs for the four smoking behaviours were not significantly associated with schizophrenia status. Pleiotropy did not inappropriately affect the results. CONCLUSIONS: Cigarette smoking is a complex behaviour in people with schizophrenia. Understanding factors underlying the observed association remains important; however, our findings do not support a causal role of smoking in influencing risk of schizophrenia.

Tacrine(10)-hupyridone, a dual-binding acetylcholinesterase inhibitor, potently attenuates scopolamine-induced impairments of cognition in mice.

Tacrine(10)-hupyridone (A10E) was designed as a dual-binding acetylcholinesterase (AChE) inhibitor from the modification of tacrine and a fragment of huperzine A. We have found that A10E effectively inhibited AChE in a mixed competitive manner, with an IC50 of 26.4 nM, which is more potent than those of tacrine and huperzine A. Most importantly, we have shown, for the first time that A10E attenuated scopolamine-induced cognitive impairments without affecting motor function in mice. A10E effectively attenuated impairments of learning and memory to a similar extent as donepezil, an inhibitor of AChE used for treating Alzheimer's disease (AD). In addition, A10E significantly decreased AChE activity in the brain of mice, suggesting that A10E might cross the brain blood-barrier. Taken together, our results demonstrated that A10E, a designed dual-binding AChE inhibitor, could effectively reverse cognitive impairments, indicating that A10E might provide therapeutic efficacy for AD treatment.

Green Tea Makes Polyphenol Nanoparticles with Radical-Scavenging Activities.

The constant demand for functional nanomaterials from natural biomass polymers usually requires new "green" synthetic strategies without using any foreign additives. Here, the green fabrication of a series of polyphenol nanoparticles (PNs) only from green tea extraction compounds is reported (i.e., tea polyphenols and theophylline). It is found that the nanoparticle formation process involves covalent copolymerization of monomers, as well as noncovalent self-assembly pathways. Additionally, the resulting PNs exhibit better free-radical scavenging activities compared with similar-sized, polydopamine-based synthetic melanin nanoparticles. This class of biomass-based functional nanoparticles is promising as green and effective antioxidant agents in general.

Fucoxanthin, a Marine Carotenoid, Reverses Scopolamine-Induced Cognitive Impairments in Mice and Inhibits Acetylcholinesterase in Vitro.

Fucoxanthin, a natural carotenoid abundant in edible brown seaweeds, has been shown to possess anti-cancer, anti-oxidant, anti-obesity and anti-diabetic effects. In this study, we report for the first time that fucoxanthin effectively protects against scopolamine-induced cognitive impairments in mice. In addition, fucoxanthin significantly reversed the scopolamine-induced increase of acetylcholinesterase (AChE) activity and decreased both choline acetyltransferase activity and brain-derived neurotrophic factor (BDNF) expression. Using an in vitro AChE activity assay, we discovered that fucoxanthin directly inhibits AChE with an IC50 value of 81.2 µM. Molecular docking analysis suggests that fucoxanthin likely interacts with the peripheral anionic site within AChE, which is in accordance with enzymatic activity results showing that fucoxanthin inhibits AChE in a non-competitive manner. Based on our current findings, we anticipate that fucoxanthin might exhibit great therapeutic efficacy for the treatment of Alzheimer's disease by acting on multiple targets, including inhibiting AChE and increasing BDNF expression.

[The anti-HIV-1 activities of benzophenones non-nucleoside reverse transcriptase inhibitors in vitro].

To evaluate the anti-HIV-1 activities of 5 benzophenones non-nucleoside reverse transcriptase inhibitors (NNRTIs) such as DY1203, DY1204, DY1119, DY1208 and DY1209 in vitro, the cytotoxicity of 5 compounds were tested on C8166, MT-4, H9 and PBMC with the MTT assay. The anti-HIV-1 activities of compounds were evaluated on laboratory-adapted strain, drug-resistant strains and primary isolated strains by p24 antigen expression ELISA. The inhibition of HIV-1 recombinant reverse transcriptase activity was assessed by ELISA assay. Among 5 compounds, DY1203 and DY1204 showed low cytotoxicities with CC(50) greater than 200 µg·m L(-1). DY1119, DY1208 and DY1209 showed strong anti-HIV-1 activities against HIV-1(IIIB,) HIV-1(74V,) HIV-1(RF/V82F/184V,) HIV-1(NL4-3) (gp41(36G)N42S,) HIV-1(KM018,) HIV-1(TC-1) and HIV-1(Wan.) However, NNRTIs drug-resistant strain HIV-1(A17) showed different resistance to these compounds. The 5 compounds proved active against HIV-1 recombinant reverse transcriptase. DY1208 is expected to become a new lead compound for its high therapeutic index. The results can provide new information for HIV-1 drug research and promote the development of new HIV-1 drugs.

Extensional Flow-Induced Concentration Gradient in Entangled Polymer Solutions with Chemically Identical Species.

Entangled polymer solutions show different rheological behavior from melts in fast extensional flow. This discrepancy is not expected according to the classic tube model and is an urgent issue to be solved in polymer physics. While in the tube model the polymer concentration is considered to be homogeneous, we show that extensional flow-induced concentration gradient may happen in polymer solutions even with chemically identical solutes and solvents. Through labeling an aggregation-induced emission (AIE) probe on oligomeric solvents, the flow-induced concentration gradient is visualized by combining extensional rheology and ex situ fluorescence microscopy. Microdomains of oligomeric solvents with a length scale of tens of micrometers are observed, and their influence on rheological behavior cannot be ignored.

Targeted Manipulation of Cellular RNA m6A Methylation at the Single-Base Level.

Development of tools for precise manipulation of cellular mRNA m6A methylation at the base level is highly required. Here, we report an RNA-guided RNA modification strategy using a fusion protein containing deactivated nuclease Cas13b and m6A methyltransferase METTL14, namely, dCas13b-M14, which is designedly positioned in the cytoplasm. dCas13b-M14 naturally heterodimerizes with endogenous METTL3 to form a catalytic complex to methylate specific cytoplasmic mRNA under a guide RNA (gRNA). We developed assays to screen and validate the guiding specificity of varied gRNAs at single-base resolution. With an optimum combination of dCas13b-M14 and gRNAs inside cells, we have successfully tuned methylation levels of several selected mRNA m6A sites. The off-target effect was evaluated by whole transcriptome m6A sequencing, and a very minor perturbation on the methylome was revealed. Finally, we successfully utilized the editing tool to achieve de novo methylations on five selected mRNA sites. Together, this study paves the way for studying position-dependent roles of m6A methylation in a particular transcript.

The role of achievement attribution in the associations between parent-child communication and psychological well-being among adolescents: A mediation analysis.

BACKGROUND: Previous studies have explored the association between parenting style and offspring's psychological well-being, and the association between offspring's achievement attribution pattern and psychological well-being. However, little is known about the role of offspring's achievement attribution in the relationship between parenting and offspring's psychological well-being. We aimed to find the role of adolescents' achievement attribution pattern in the relationship between parent-child communication quality and adolescents' mental health. METHODS: A cross-sectional analysis was conducted on 2,725 adolescents aged from 9 to 18 years who are participating in the China Family Panel Studies. Participants supplied demographic information and completed a series of psychological scales including the Center for Epidemiologic Studies Depression scale, an adapted version of the Parental Bonding Instrument, an achievement attribution scale, and single-item measures of subjective well-being and subjective interpersonal popularity. RESULTS: Linear regression analysis revealed that after controlling for demographic factors good parent-child communication negatively correlated with depression symptoms, and positively associated with subjective well-being and subjective interpersonal popularity. Next, mediation analysis found that internal attribution of achievement partly mediated the effects of parent-child communication quality on adolescents' depression, subjective well-being, and subjective interpersonal popularity. The result was robust after controlling demographic variables. CONCLUSIONS: An internal attribution pattern of achievement partially accounted for the associations between parent-child communication quality and adolescents' psychological outcomes including depression, subjective well-being, and subjective interpersonal popularity. Future interventions for adolescents' mental health promotion can target parent-child communication and adolescents' positive achievement attribution pattern.

Precise identification of an RNA methyltransferase's substrate modification site.

Here we report a simple and nonradioactive biochemical assay which is capable of accurately determining the substrate methylation sites of human RNA N6-methyladenosine methyltransferases METTL3/METTL14 and METTL16. This method employs enzyme-assisted chemical labelling of a specific base in an RNA substrate with the assistance of an allyl-substituted methyltransferase cofactor, and enables precise identification of the labelling site by a mutation signal from standard nucleic acid sequencing. Our method provides a platform to investigate the enzymatic methylations of long and structurally complex RNA substrates, and facilitates the discovery of new methyltransferases.

Green Nanoparticle Scavengers against Oxidative Stress.

The usage of exogenous antioxidant materials to relieve oxidative stress offers an important strategy for the therapy of oxidative stress-induced injuries. However, the fabrication processes toward the antioxidant materials usually require the involvement of extra metal ions and organic agents, as well as sophisticated purification steps, which might cause tremendous environmental stress and induce unpredictable side effects in vivo. To address these issues, herein, we proposed a novel strategy to fabricate green nanoparticles for efficiently modulating oxidative stress, which was facilely prepared from tea polyphenol extracts (originated from green tea) via a green enzymatic polymerization-based chemistry method. The resulting nanoparticles possessed a uniform spherical morphology and good stability in water and biomedium and demonstrated excellent radical scavenging properties. These nanoparticle scavengers could effectively prevent intracellular oxidative damage, accelerate wound recovery, and protect the kidneys from reactive oxygen species damaging in the acute kidney injury model. We hope this work will inspire the further development of more types of green nanoparticles for antioxidant therapies via similar synthetic strategies using green biomass materials.

Network pharmacology-based exploration of therapeutic mechanism of Liu-Yu-Tang in atypical antipsychotic drug-induced metabolic syndrome.

BACKGROUND: Metabolic syndrome (MetS) is prevalent in patients receiving atypical antipsychotic drugs (AADs), but there are few effective interventions. The Traditional Chinese herbal decoction Liu-Yu-Tang (LYT) has achieved clinical improvement for AAD-induced MetS, but its pharmacological mechanism remains unclear. METHOD: A network pharmacology-based method was utilized in this study. First, the TCMSP and SwissTargetPrediction database were used to acquire plasma-absorbed components and putative targets of LYT, respectively. Second, an interaction network between shared targets of LYT and MetS was constructed using STRING online tool. Topological analyses were performed to extract hub gene targets. Finally, we did a pathway analysis of gene targets using the Kyoto Encyclopedia of Genes and Genomes (KEGG) to find biological pathways of LYT. RESULTS: We obtained 655 putative targets of LYT, 434 known targets of AADs, and 1577 MetS-related gene targets. There are 232 shared targets between LYT and MetS. Interaction network construction and topological analysis yielded 60 hub targets, of which 18 were major hub targets, among which IL-6, IL-8, TNF, PI3K, MAPK, and NF-κB (RELA) are the most important in LYT's treatment of AAD-induced MetS. Pathway enrichment analysis revealed a statistically high significance of the AGE-RAGE signaling pathway in diabetic complications, lipid and atherosclerosis and the insulin resistance pathway. CONCLUSIONS: LYT may control activities of the pro-inflammatory cytokines IL-6, IL-8, TNF and the important signal transduction molecules PI3K, MAPKs, and NF-κB (RELA), regulating metabolic disturbance-related pathways like the AGE-RAGE signaling pathway in diabetic complications, lipid and atherosclerosis, and the insulin resistance pathway, generating therapeutic effects for AAD-induced MetS.

Genetic risk of clozapine-induced leukopenia and neutropenia: a genome-wide association study.

BACKGROUND: Clozapine is considered to be the most effective antipsychotic medication for schizophrenia. However, it is associated with several adverse effects such as leukopenia, and the underlying mechanism has not yet been fully elucidated. The authors performed a genome-wide association study (GWAS) in a Chinese population to identify genetic markers for clozapine-induced leukopenia (CIL) and clozapine-induced neutropenia (CIN). METHODS: A total of 1879 patients (225 CIL cases, including 43 CIN cases, and 1,654 controls) of Chinese descent were included. Data from common and rare single nucleotide polymorphisms (SNPs) were tested for association. The authors also performed a trans-ancestry meta-analysis with GWAS results of European individuals from the Clozapine-Induced Agranulocytosis Consortium (CIAC). RESULTS: The authors identified several novel loci reaching the threshold of genome-wide significance level (P < 5 × 10-8). Three novel loci were associated with CIL while six were associated with CIN, and two T cell related genes (TRAC and TRAT1) were implicated. The authors also observed that one locus with evidence close to genome-wide significance (P = 5.08 × 10-8) was near the HLA-B gene in the major histocompatibility complex region in the trans-ancestry meta-analysis. CONCLUSIONS: The associations provide novel and valuable understanding of the genetic and immune causes of CIL and CIN, which is useful for improving clinical management of clozapine related treatment for schizophrenia. Causal variants and related underlying molecular mechanisms need to be understood in future developments.

SNX29, a new susceptibility gene shared with major mental disorders in Han Chinese population.

OBJECTIVES: Environmental and genetic factors play important roles in the development of schizophrenia (SCZ), bipolar disorder (BPD) or major depressive disorder (MDD). Some risk loci are identified with shared genetic effects on major psychiatric disorders. To investigate whether SNX29 gene played a significant role in these psychiatric disorders in the Han Chinese population. METHODS: We focussed on 11 single-nucleotide polymorphisms (SNPs) harbouring SNX29 gene and carried out case-control studies in patients with SCZ (n = 1248), BPD (n = 1344), or MDD (n = 1056), and 1248 healthy controls (HC) recruited from the Han Chinese population. We constructed weighted gene co-expression network analysis (WGCNA) and extracted significant modules by R package. RESULTS: We found that rs3743592 was significantly associated with MDD and rs6498263 with BPD in both allele and genotype distributions. Before correction, rs3743592 showed allelic and genotypic significance with SCZ, rs6498263 showed allelic significance with SCZ. WGCNA identified top 10 modules of co-expressed genes. Gene Ontology (GO) and pathway analysis were used to examine the functions of SNX29, which revealed that SNX29 was involved in the regulation of a number of biological processes, such as TGF-beta, ErbB, and Wnt signalling pathway, etc. CONCLUSIONS: Our results supported common risk factors in SNX29 might share among these three mental disorders in the Han Chinese population.

Patient health questionnaire-15 (PHQ-15) to distinguish bipolar II disorder from major depressive disorder.

A sequential-recruited clinical trial has been conducted to assess capacity of Patient Health Questionnaire-15 (PHQ-15) in distinguishing bipolar II disorder from major depressive disorder. A total of 73 patients (49 BD-II depression patients) filled sociodemographic characteristics, Patient Health Questionnaire-9 (PHQ-9), Generalized Anxiety Disorder-7 Questionnaire (GAD-7), and PHQ-15. Sum score of PHQ-15 showed statistically significant difference in the two groups (t-test, P = 0.027). The area under the curve was 0.663 (P = 0.025), and the specificity was 0.75 at sum score of 13. Patients with BD-II depression has more somatic symptoms than MDD, and PHQ-15 might be used for identification.

The New NNRTI ACC007 Combined with Lamivudine and Tenofovir Disoproxil Fumarate Show Synergy Anti-HIV Activity In Vitro.

BACKGROUND: Acquired immunodeficiency syndrome can hardly be cured currently and people with human immunodeficiency virus (HIV) need lifelong treatment that may result in the emergence of drug resistance which leads to failed treatment. Thus, the development of new anti- HIV drugs and new treatment regimens are necessary. OBJECTIVE: The aim of this study is to analyze the combined anti-HIV activity of tenofovir disoproxil fumarate, lamivudine and ACC007, a new non-nucleoside reverse transcriptase inhibitor. METHODS: The antiviral activity of tenofovir disoproxil fumarate, lamivudine and ACC007 alone or in combination against different HIV-1 strains was determined by the detection of HIV-1 p24 level through enzyme-linked immunosorbent assay. RESULT: ACC007 showed EC50 of nanomolar range (from 3.03 nM to 252.59 nM) against all HIV-1 strains used in this study except the HIV-1A17, with EC50 of 1.57 µM. The combined antiviral activity of ACC007, lamivudine and tenofovir disoproxil fumarate showed synergy antiviral activity against all HIV-1 strains used in this study. The three-drug combination showed moderate synergism against HIV-1A17, HIV-14755-5, HIV-1K103N and HIV-1V106M, with a combination index value ranging from 0.71 to 0.87, and showed synergism against the other HIV-1 strains with combination index value from 0.35 to 0.67. The combination with ACC007 significantly increases the dose reduction index value of lamivudine and tenofovir disoproxil fumarate, compared with two-drug combination. CONCLUSION: ACC007 exhibits potent antiviral activity alone or with 3TC and TDF, and exerts synergistic effect against all HIV strains used in our investigation in vitro.

Network pharmacology-based identification for therapeutic mechanism of Ling-Gui-Zhu-Gan decoction in the metabolic syndrome induced by antipsychotic drugs.

BACKGROUND: The metabolic syndrome (MetS) is a common side effect of second-generation antipsychotic drugs (SGAs), leading to poor prognosis in patients with mental illness. The traditional Chinese herbal formula Ling-Gui-Zhu-Gan decoction (LGZGD) is a clinically validated remedy for SGAs-induced MetS, but its underlying mechanism remains unclear. METHODS: A network pharmacology-based analysis was performed to explore predicted plasma-absorbed components, putative therapeutic targets, and main pathways involved in LGZGD bioactivity. We constructed a target interaction network between the predicted targets of LGZGD and the known targets of MetS, after which we extracted major hubs using topological analysis. Thereafter, the maximum value of "edge betweenness" of all interactions was defined as a bottleneck, which suggested its importance in connecting all targets in the network. Finally, a pathway enrichment analysis of major hubs was used to reveal the biological functions of LGZGD. RESULTS: This approach identified 120 compounds and 361 candidate targets of LGZGD. According to the data generated in this study, the interaction between JUN and APOA1 plays a vital role in the treatment of SGAs-induced MetS using LGZGD. Interestingly, JUN was a putative target of LGZGD and APOA1 is one of the known targets of both MetS and SGAs (olanzapine and clozapine). LGZGD was significantly associated with several pathways including PI3K-Akt signaling, insulin resistance, and MAPK signaling pathway. CONCLUSIONS: LGZGD might inhibit JUN and thereby increases the expression of APOA1 to maintain metabolic homeostasis via some vital pathways.

14-Formyl-15-aryloxy/methoxymatrine and 14-Aryloxymethylidenyl-matrine Derivatives as Anti-HIV-1 Agents.

BACKGROUND: The human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS) has always been a global health threat and leading cause of deaths. However, due to the emergence of drug-resistant HIV, an inevitable consequence of increasing use of antiretroviral drugs posed a major threat to antiretroviral therapy success. OBJECTIVE: The discovery of anti-HIV-1 agents will be used for the effective treatment of HIV/AIDS. METHOD: In continuation of our program aimed to discover anti-HIV-1 agents, twelve matrine derivatives, such as 14-formyl-15-aryloxy/methoxymatrines (3a-j) and 14-aryloxymethylidenylmatrines (3k,l), were semi-prepared from matrine, and evaluated against HIV-1 IIIB replication in acutely infected C8166 cells in vitro. RESULTS: Among them, compound 3j showed the most potent anti-HIV-1 activity with EC50 and therapeutic index (TI) values of 1.79 µg/mL, and 98.2, respectively. CONCLUSION: It has been demonstrated that the positions of methyl on the phenyl ring and 14- formylmatrine-15-oxy on the naphthyl ring were very important for the activity. It will lay the foundation for further structural modification and application of matrines as HIV-1 inhibitors.