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The chemical composition of Ganoderma lucidum ethanol extracts was systematically analyzed and identified by ultra-high performance liquid chromatography-quadrupole electrostatic field orbitrap high-resolution mass spectrometry(UPLC-Orbitrap-HRMS). The fragmentation pattern of the representative chemical compounds was summarized, and the potential anti-liver fibrosis active compounds of G. lucidum acting on the farnesoid X receptor(FXR) target were studied to elucidate its pharmacodynamic substance basis. Preliminarily, 95 chemical constituents of G. lucidum ethanol extracts were identified, including 24 ganoderic acids, 9 ganoderenic acids, 13 lucidenic acids, 3 ganolucidic acids, 1 ganoderma lactone, 40 other triterpenoids, 4 fatty acids, and 1 other constituent. In addition, the fragmentation patterns of the representative compounds were also analyzed. The structural characteristics of ganoderic acids and ganoderenic acids were the C30 skeleton, containing free-COOH and-OH groups, which could easily lose H_2O and CO_2 to form fragment ions. The D-ring was mostly a five-membered ring, which was prone to breakage. Lucidenic acids were the lanosterolane-type of the C27 skeleton, and the side-chain structure became shorter and contained the same free-COOH and-OH compared with ganoderic acids, which had been reduced from 8 to 5 cartons and prone to lose H_2O and CO_2. Then, six reported FXR receptor agonists were selected to form a training set for establishing a pharmacophore model based on FXR ligands. The 95 identified chemical constituents of G. lucidum were matched with the pharmacophore, and the optimal pharmacophore model 02(sensitivity=0.750 00, specificity=0.555 56, ROC=0.750) was selected for the virtual screening of the G. lucidum compound library through the validation of the test set. Finally, 31 potential G. lucidum active constituents were screened and chosen to activate the FXRs. The ADMET results showed that ganoderic acid H and lucidenic acid J had less than 90% plasma protein binding rate and no hepatotoxicity, which could be used as FXR activators for developing clinical drugs for the treatment of liver fibrosis, either alone or in combination.

TRMT1 is an N 2 -methylguanosine (m 2 G) and N 2 ,N 2 -methylguanosine (m 2 2 G) methyltransferase that targets G26 of both cytoplasmic and mitochondrial tRNAs. In higher eukaryotes, most cytoplasmic tRNAs with G26 carry m 2 2 G26, although the majority of mitochondrial G26-containing tRNAs carry m 2 G26 or G26, suggesting differences in the mechanisms by which TRMT1 catalyzes modification of these tRNAs. Loss-of-function mutations of human TRMT1 result in neurological disorders and completely abrogate tRNA:m 2 2 G26 formation. However, the mechanism underlying the independent catalytic activity of human TRMT1 and identity of its specific substrate remain elusive, hindering a comprehensive understanding of the pathogenesis of neurological disorders caused by TRMT1 mutations. Here, we showed that human TRMT1 independently catalyzes formation of the tRNA:m 2 G26 or m 2 2 G26 modification in a substrate-dependent manner, which explains the distinct distribution of m 2 G26 and m 2 2 G26 on cytoplasmic and mitochondrial tRNAs. For human TRMT1-mediated tRNA:m 2 2 G26 formation, the semi-conserved C11:G24 serves as the determinant, and the U10:A25 or G10:C25 base pair is also required, while the size of the variable loop has no effect. We defined the requirements of this recognition mechanism as the "m 2 2 G26 criteria". We found that the m 2 2 G26 modification occurred in almost all the higher eukaryotic tRNAs conforming to these criteria, suggesting the "m 2 2 G26 criteria" are applicable to other higher eukaryotic tRNAs., (© 2023. Science China Press.)

Background: Adult neurogenesis plays an important role in repairing damaged neurons and improving cognitive impairment in Alzheimer's disease (AD). B. Papyrifera (L.) L'Hér. ex Vent. fruits (BL), a traditional Chinese medicine for tonifying the kidney, has been reported to improve cognitive function in AD mice, but the underlying mechanisms have not been clearly illuminated. This study aimed to provide an overview of the differential compounds in the brain of APP/PS1 mice after BL water extract (BLWE) treatment through metabolomics technology and to elucidate whether the therapeutic effect and mechanism are through the enhancement of neurogenesis. Methods: APP/PS1 transgenic mice were treated with different doses of BLWE. After 6 weeks of intragastric injection, the therapeutic effects of BLWE on APP/PS1 transgenic mice were determined by the Morris water maze test, immunohistochemistry, hematoxylin & eosin and Nissl staining, enzyme-linked immunosorbent assay and terminal deoxynucleotidyl transferase dUTP nick end labeling staining. Subsequently, metabolomics technology was used to analyze the regulatory effect of BLWE on differential compounds in the brain of APP/PS1 mice, and on this basis, its molecular mechanism of BLWE was screened. Finally, the protein expression of the Wnt/β-catenin signaling pathway was detected by Western blotting. Results: After BLWE treatment, the learning and memory function of APP/PS1 mice were significantly improved, which was related to the increase in the number of Nestin + /BrdU + and NeuN + /BrdU + cells, and the decrease in the number of apoptotic cells in the hippocampus. BLWE treatment could also up-regulate the expression of synapse-associated proteins. Moreover, BLWE could modulate endogenous metabolic compounds in the brains of AD mice, including N-acetyl-aspartate, glutamine, etc. Furthermore, BLWE inhibited the phosphorylation of Tyr216-GSK-3β and β-catenin protein while increased CyclinD 1 protein expression. Conclusion: We demonstrated that BLWE can enhance neural stem cells proliferation and improve neurogenesis, thereby efficiently repairing damaged neurons in the hippocampus and ameliorating cognitive impairment in APP/PS1 transgenic mice. The mechanism is at least partly through activating the Wnt/β-catenin signaling pathway., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Yan, Huang, Xiong, Song, Li, Yang, Sun, Zhang and Ji.)

Since numerous RNAs and RBPs prevalently localize to active chromatin regions, many RNA-binding proteins (RBPs) may be potential transcriptional regulators. RBPs are generally thought to regulate transcription via noncoding RNAs. Here, we describe a distinct, dual mechanism of transcriptional regulation by the previously uncharacterized tRNA-modifying enzyme, hTrmt13. On one hand, hTrmt13 acts in the cytoplasm to catalyze 2'-O-methylation of tRNAs, thus regulating translation in a manner depending on its tRNA-modification activity. On the other hand, nucleus-localized hTrmt13 directly binds DNA as a transcriptional co-activator of key epithelial-mesenchymal transition factors, thereby promoting cell migration independent of tRNA-modification activity. These dual functions of hTrmt13 are mutually exclusive, as it can bind either DNA or tRNA through its CHHC zinc finger domain. Finally, we find that hTrmt13 expression is tightly associated with poor prognosis and survival in diverse cancer patients. Our discovery of the noncatalytic roles of an RNA-modifying enzyme provides a new perspective for understanding epitranscriptomic regulation., (© 2021 The Authors. Published under the terms of the CC BY NC ND 4.0 license.)

Dnmt2, a member of the DNA methyltransferase superfamily, catalyzes the formation of 5-methylcytosine at position 38 in the anticodon loop of tRNAs. Dnmt2 regulates many cellular biological processes, especially the production of tRNA-derived fragments and intergenerational transmission of paternal metabolic disorders to offspring. Moreover, Dnmt2 is closely related to human cancers. The tRNA substrates of mammalian Dnmt2s are mainly detected using bisulfite sequencing; however, we lack supporting biochemical data concerning their substrate specificity or recognition mechanism. Here, we deciphered the tRNA substrates of human DNMT2 (hDNMT2) as tRNAAsp(GUC), tRNAGly(GCC) and tRNAVal(AAC). Intriguingly, for tRNAAsp(GUC) and tRNAGly(GCC), G34 is the discriminator element; whereas for tRNAVal(AAC), the inosine modification at position 34 (I34), which is formed by the ADAT2/3 complex, is the prerequisite for hDNMT2 recognition. We showed that the C32U33(G/I)34N35 (C/U)36A37C38 motif in the anticodon loop, U11:A24 in the D stem, and the correct size of the variable loop are required for Dnmt2 recognition of substrate tRNAs. Furthermore, mammalian Dnmt2s possess a conserved tRNA recognition mechanism., (© The Author(s) 2021. Published by Oxford University Press on behalf of Nucleic Acids Research.)

Post-transcriptional modifications affect tRNA biology and are closely associated with human diseases. However, progress on the functional analysis of tRNA modifications in metazoans has been slow because of the difficulty in identifying modifying enzymes. For example, the biogenesis and function of the prevalent N2-methylguanosine (m2G) at the sixth position of tRNAs in eukaryotes has long remained enigmatic. Herein, using a reverse genetics approach coupled with RNA-mass spectrometry, we identified that THUMP domain-containing protein 3 (THUMPD3) is responsible for tRNA: m2G6 formation in human cells. However, THUMPD3 alone could not modify tRNAs. Instead, multifunctional methyltransferase subunit TRM112-like protein (TRMT112) interacts with THUMPD3 to activate its methyltransferase activity. In the in vitro enzymatic assay system, THUMPD3-TRMT112 could methylate all the 26 tested G6-containing human cytoplasmic tRNAs by recognizing the characteristic 3'-CCA of mature tRNAs. We also showed that m2G7 of tRNATrp was introduced by THUMPD3-TRMT112. Furthermore, THUMPD3 is widely expressed in mouse tissues, with an extremely high level in the testis. THUMPD3-knockout cells exhibited impaired global protein synthesis and reduced growth. Our data highlight the significance of the tRNA: m2G6/7 modification and pave a way for further studies of the role of m2G in sperm tRNA derived fragments., (© The Author(s) 2021. Published by Oxford University Press on behalf of Nucleic Acids Research.)

Members of the mammalian AlkB family are known to mediate nucleic acid demethylation 1,2 . ALKBH7, a mammalian AlkB homologue, localizes in mitochondria and affects metabolism 3 , but its function and mechanism of action are unknown. Here we report an approach to site-specifically detect N 1 -methyladenosine (m 1 A), N 3 -methylcytidine (m 3 C), N 1 -methylguanosine (m 1 G) and N 2 ,N 2 -dimethylguanosine (m 2 2 G) modifications simultaneously within all cellular RNAs, and discovered that human ALKBH7 demethylates m 2 2 G and m 1 A within mitochondrial Ile and Leu1 pre-tRNA regions, respectively, in nascent polycistronic mitochondrial RNA 4-6 . We further show that ALKBH7 regulates the processing and structural dynamics of polycistronic mitochondrial RNAs. Depletion of ALKBH7 leads to increased polycistronic mitochondrial RNA processing, reduced steady-state mitochondria-encoded tRNA levels and protein translation, and notably decreased mitochondrial activity. Thus, we identify ALKBH7 as an RNA demethylase that controls nascent mitochondrial RNA processing and mitochondrial activity., (© 2021. The Author(s), under exclusive licence to Springer Nature Limited.)

Kaempferol is a major flavonoid in Ginkgo Folium and other edible plants, which is being proposed here to have roles in angiogenesis. Angiogenesis is important in both physiological and pathological development. Here, kaempferol was shown to bind with vascular endothelial growth factor (VEGF), probably in the heparin binding domain of VEGF: this binding potentiated the angiogenic functions of VEGF in various culture models. Kaempferol potentiated the VEGF-induced cell motility in human umbilical vein endothelial cells (HUVECs), as well as the sub-intestinal vessel sprouting in zebrafish embryos and formation of microvascular in rat aortic ring. In cultured HUVECs, application of kaempferol strongly potentiated the VEGF-induced phosphorylations of VEGFR2, endothelial nitric oxide synthase (eNOS) and extracellular signal-regulated kinase (Erk) in time-dependent and concentration-dependent manners, and in parallel the VEGF-mediated expressions of matrix metalloproteinases (MMPs), MMP-2 and MMP-9, were significantly enhanced. In addition, the potentiation effect of kaempferol was revealed in VEGF-induced migration of skin cell and monocyte. Taken together, our results suggested the pharmacological roles of kaempferol in potentiating VEGF-mediated functions should be considered., (Copyright © 2020 Hu, Wang, Xia, Dai, Xiong, Dong, Duan, Chan, Qin and Tsim.)

Resveratrol is a polyphenol commonly found in plants and food health products, such as grape and red wine, and was identified for its binding to vascular endothelial growth factor (VEGF) by using HerboChips screening. The binding, therefore, resulted in alterations of VEGF binding to its receptor and revealed the roles of VEGF in angiogenesis. Several lines of evidence gave support to the inhibitory activities of resveratrol in VEGF-triggered angiogenesis. In human umbilical vein endothelial cells (HUVECs), compared with a VEGF-induced group, resveratrol, at a high concentration, suppressed VEGF-mediated endothelial cell proliferation, cell migration, cell invasion, and tube formation by 80 ± 9.01%, 140 ± 3.78%, 110 ± 7.51%, and 120 ± 10.26%, respectively. Moreover, resveratrol inhibited the subintestinal vessel formation in zebrafish embryo. In signaling cascades, application of resveratrol in HUVECs reduced the VEGF-triggered VEGF receptor 2 phosphorylation and c-Jun N-terminal kinase phosphorylation. Moreover, the VEGF-mediated phosphorylations of endothelial nitric oxide synthase, protein kinase B, and extracellular signal-regulated kinase were obviously decreased by (3 ± 0.37)-, (2 ± 0.27)- and (6 ± 0.23)-fold, respectively, in the presence of resveratrol at high concentration. Parallelly, the VEGF-induced reactive oxygen species formation was significantly decreased by 50 ± 7.88% to 120 ± 14.82% under resveratrol treatment. Thus, our results provided support to the antiangiogenic roles of resveratrol, as well as its related signaling mechanisms, in attenuating the VEGF-mediated responses. The present results supported possible development of resveratrol, which should be considered as a therapeutic agent in terms of prevention and clinical treatment of diseases related to angiogenesis.

Polydatin, also called piceid, is a stilbenoid glucoside of a resveratrol derivative. It derives mainly from the root and rhizome of Polygonum cuspidatum Sieb. et Zucc. Although the role of P. cuspidatum root in angiogenesis has been reported, the active chemical or chemicals responsible for such function is not known. Here, polydatin was proposed to bind VEGF, which therefore altered the functions of VEGF in angiogenesis. Several lines of evidence supported the pharmaceutical effects of polydatin in VEGF-induced angiogenesis. In human umbilical vein endothelial cells, polydatin inhibited VEGF-stimulated cell proliferation, cell migration, and tube formation. Moreover, polydatin showed suppressive effects on the subintestinal vessel formation in zebrafish embryos. In signaling cascades, polydatin application attenuated VEGF-induced phosphorylations of VEGF receptor 2 and JNK. Moreover, the VEGF-induced phosphorylations of Akt, eNOS, and Erk were significantly decreased in the presence of polydatin. In parallel, the formation of reactive oxygen species, triggered by VEGF, was markedly decreased under polydatin application. Thus, our results supported the angiogenic roles of polydatin, as well as its signaling mechanism in blocking VEGF-mediated responses. The current study provides support for the possible development of polydatin as a potential therapeutic agent for treatment and prevention of angiogenesis-related diseases.-Hu, W.-H., Wang, H.-Y., Kong, X.-P., Xiong, Q.-P., Poon, K. K.-M., Xu, L., Duan, R., Chan, G. K.-L., Dong, T. T.-X., Tsim, K. W.-K. Polydatin suppresses VEGF-induced angiogenesis through binding with VEGF and inhibiting its receptor signaling.

Acetylcholinesterase (AChE) hydrolyzes the neurotransmitter acetylcholine in neurons. However, AChE has been proposed to also have nonneuronal functions in different cell types. Here, we report that AChE is expressed in melanocytes and melanoma cells, and that the tetrameric (G4) form is the major AChE isoform in these cells. During melanogenesis of B16F10 murine melanoma cells, AChE levels decreased markedly. The differentiation of melanoma cells led to (i) an increase in melanin and tyrosinase, (ii) a change in intracellular cAMP levels, and (iii) a decrease in microphthalmia-associated transcription factor (MITF). We hypothesized that the regulation of AChE during melanogenesis is mediated by two transcription factors: cAMP-response element-binding protein (CREB) and MITF. In melanoma cells, exogenous cAMP suppressed AChE expression and the promoter activity of the ACHE gene. This suppression was mediated by a cAMP-response element (CRE) located on the ACHE promoter, as mutation of CRE relieved the suppression. In melanoma, MITF overexpression induced ACHE transcription, and mutation of an E-box site in human ACHE promoter blocked this induction. An AChE inhibitor greatly enhanced acetylcholine-mediated responses of melanogenic gene expression levels in vitro ; however, this enhancement was not observed in the presence of agonists of the muscarinic acetylcholine receptor. These results indicate that ACHE transcription is regulated by cAMP-dependent signaling during melanogenesis of B16F10 cells, and the effect of this enzyme on melanin production suggests that it has a potential role in skin pigmentation., (© 2018 Wu et al.)

Cordycepin has been widely used in oriental countries to maintain health and improve physical performance. Compound nerve action potential (CNAP), which is critical in signal conduction in the peripheral nervous system, is necessary to regulate physical performance, including motor system physiological and pathological processes. Therefore, regulatory effects of cordycepin on CNAP conduction should be elucidated. In this study, the conduction ability of CNAP in isolated frog sciatic nerves was investigated. Results revealed that cordycepin significantly decreased CNAP amplitude and conductive velocity in a reversible and concentration-dependent manner. At 50 mg/L cordycepin, CNAP amplitude and conductive velocity decreased by 62.18 ± 8.06% and 57.34% ± 6.14% compared with the control amplitude and conductive velocity, respectively. However, the depressive action of cordycepin on amplitude and conductive velocity was not observed in Ca(2+)-free medium or in the presence of Ca(2+) channel blockers (CdCl2/LaCl3). Pretreatment with L-type Ca(2+) channel antagonist (nifedipine/deltiazem) also blocked cordycepin-induced responses; by contrast, T-type and P-type Ca(2+) channel antagonists (Ni(2+)) failed to block such responses. Therefore, cordycepin decreased the conduction ability of CNAP in isolated frog sciatic nerves via L-type Ca(2+) channel-dependent mechanism.

Isolated toad gastrocnemius muscle is a typical skeletal muscle tissue that is frequently used to study the motor system because it is an important component of the motor system. This study investigates the effects of cordycepin on the skeletal muscle contractile function of isolated toad gastrocnemius muscles by electrical field stimulation. Results showed that cordycepin (20 mg/l to 100 mg/l) significantly decreased the contractile responses in a concentration-dependent manner. Cordycepin (50 mg/l) also produced a rightward shift of the contractile amplitude-stimulation intensity relationship, as indicated by the increases in the threshold stimulation intensity and the saturation stimulation intensity. However, the most notable result was that the maximum amplitude of the muscle contractile force was significantly increased under cordycepin application (122±3.4% of control). This result suggests that the skeletal muscle contractile function and muscle physical fitness to the external stimulation were improved by the decreased response sensitivity in the presence of cordycepin. Moreover, cordycepin also prevented the repetitive stimulation-induced decrease in muscle contractile force and increased the recovery amplitude and recovery ratio of muscle contraction. However, these anti-fatigue effects of cordycepin on muscle contraction during long-lasting muscle activity were absent in Ca2+-free medium or in the presence of all Ca2+ channels blocker (0.4 mM CdCl2). These results suggest that cordycepin can positively affect muscle performance and provide ergogenic and prophylactic benefits in decreasing skeletal muscle fatigue. The mechanisms involving excitation-coupled Ca2+ influxes are strongly recommended.

Objective: To prepare resveratrol solid lipid nanoparticles (Res-SLN) and investigate its physical and chemical speciality and anticancer effects in vitro., Methods: Res-SLN was prepared by the solvent emulsification-evaporation method. Its morphology, particle size and zata potential were examined by transmission electron microscope and laser granularity equipment. Its entrapment efficiency, drug loading, release concentration were determined by HPLC. Its anticancer effect of Res-SLN in vitro were studied by MTT., Results: Res-SLN assumed spherical shape. Its distribution of diameter was even with average particle size of 96. 7 nm, zata potential was--16.3mV, drug loading was (7.95 +/- 0.21)%, entrapment efficiency was (91.34 +/- 0.18)%; Res-SLN could retard drug release in vitro and its cytotoxicity was significantly higher than that of oridonin solution against HepG2 cells., Conclusion: Res-SLN has high entrapment efficiency and drug loading, uniform particle size, and can retard drug release in vitro and enhance anticancer effect.

Objective: To study the preparation of alpha-Hydrocycholic-beta-Cyclodextrin inclusion compound., Methods: It was studied with orthogonal design to analysis three factors of inclusion rate such as the weight ratio between HDCA and beta-Cyclodextrin, the temperature and the reaction time. Fourier transform infrared spectroscopy, scanning electron microscopy, taste and solubility test were used to identify the inclusion compound., Results: Stable inclusion compound was made by HDCA and beta-Cyclodextrin. The weight ratio between HDCA and beta-Cyclodextrin was the most important factor. The alpha-Hydrocycholic-beta-Cyclodextrin inclusion compound taste and the solubility were improved., Conclusion: The optimum preparation condition is alpha-Hydrocycholic : beta-Cyclodextrin = 8.67 : 1, the inclusion temperature is 60 degrees C and the inclusion time is 30 minutes.