New compounds with hepatoprotective effects from the stems of Sabia parviflora.

Three new compounds, (8S)-2,2,7,7-tetramethyl-8-hydroxymethyl-6H-indanone-(2,3-b)-2H-pyran-9-O-ß-d-glucopyranoside (1), (7S,8S)-2,2,7-trimethyl-7-hydroxymethyl-8-hydroxy-2,7,8,9-tetrahydro-6H-naphtho-(2,3-b)-pyran-10-O-ß-d-glucopyranoside (2), 1-deoxy-1-(3,4-dihydro-7-methyl-2,3-dioxo-1(2H)-quinoxalinyl)pentitol-6-carboxylic acid (3), as well as six known compounds (4-9), were obtained. Their structures were determined by spectroscopy and comparison with NMR data of related compounds. Absolute configurations were determined by ECD spectroscopy. The hepatoprotective effects of these compounds were investigated on HepG2 and LO2 cells lines; compounds 1, 2, and 4 displayed moderate activity.

Combined Relativistic Ab Initio Multireference and Experimental Study of the Electronic Structure of Terbium Luminescent Compound.

A new terbium (III) luminescent compound {[Tb2(PDC)2(ox)(H2O)4](H2O)2}n was synthesized by the self-assembly of Tb3+ ions with 3,5-pyridinedicarboxylate (PDC) and oxalate (ox) ligands and characterized by fluorescence spectroscopy and single-crystal X-ray diffraction. The density functional theory (DFT) and high-level correlated ab initio wave function methods with Spin-Orbit Coupling correction (CASSCF/SO and CAS-NEVPT2/SOC) were successfully applied to predict the absorption and emission spectra of this strongly correlated lanthanide system in excellent agreement with the experimental results.

Effects of PAK4/LIMK1/Cofilin-1 signaling pathway on proliferation, invasion, and migration of human osteosarcoma cells.

PURPOSE: To explore the effects of PAK4/LIMK1/Cofilin-1 signaling pathway on the proliferation, invasion, and migration of human osteosarcoma cells. METHODS: The expression of PAK4/LIMK1/Cofilin-1 was detected by immunohistochemistry in osteosarcoma tissues. The osteosarcoma cell line MG63 was transfected and divided into Mock, Control siRNA, si-PAK4, LIMK1, and si-PAK4+LIMK1 groups. Then, the cellular biological features of MG63 cells were detected by CCK-8, wound-healing, Transwell, and flow cytometry methods. The relationship of PAK4 and LIMK1 was performed by co-immunoprecipitation test, and the protein expression of PAK4/LIMK1/Cofilin-1 was determined by Western blotting. Finally, the effect of PAK4 on the growth of osteosarcoma was verified by subcutaneous transplantation model of osteosarcoma in nude mice. RESULTS: The expression of PAK4/LIMK1/Cofilin-1 in both osteosarcoma tissues and cells was up-regulated. Positive PAK4, LIMK1, and Cofilin-1 expressions in osteosarcoma were associated with the clinical stage, distant metastasis, and tumor grade. The MG63 cell viability, migration, and invasion, as well as the expression of PAK4, p-LIMK/LIMK, and p-Cofilin-1/Cofilin-1, were restrained by the knock down of PAK4 while it promoted apoptosis. PAK4 silencing also suppressed the growth of subcutaneous transplanted tumor in nude mice. Co-immunocoprecipitation showed that LIMK and PAK4 protein can form complex in osteosarcoma cells. Besides, LIMK1 overexpression reversed the inhibition effect of PAK4 siRNA on the growth of osteosarcoma cells. CONCLUSION: The expression of PAK4/LIMK1/Cofilin-1 pathway in osteosarcoma tissues was up-regulated. Thus, PAK4 inhibition may restrict the osteosarcoma cell proliferation, invasion, and migration but promote its apoptosis via decreasing the activity of LIMK1/Cofilin-1 pathway.

Isolation of chemical constituents with anti-inflammatory activity from Reineckia carnea herbs.

Three new saponins (1-3), a new natural product (4) and six other known compounds (5-10) were isolated from the whole Reineckia carnea plant. Their structures were established by comparison of their NMR spectra and MS data with literature data. In addition, all the isolated compounds were evaluated in vitro for anti-inflammatory activities against LPS-stimulated nitric oxide (NO) production in RAW 264.7 macrophages. Compounds 1-4 exhibited anti-inflammatory activities with IC50 values of 37.5 µM, 31.4 µM, 34.6 µM, and 56.1 µM, respectively. Furthermore, compounds 5-10 showed anti-inflammatory activities with IC50 values ranging from 20.3 to 42.9 µM.

microRNA-374 inhibits proliferation and promotes apoptosis of mouse melanoma cells by inactivating the Wnt signalling pathway through its effect on tyrosinase.

Melanoma is one of the most malignant skin tumours with constantly increasing incidence worldwide. Previous studies have demonstrated that microRNA-374 (miR-374) is a novel biomarker for cancer therapy. Therefore, this study explores whether miR-374 targeting tyrosinase (TYR) affects melanoma and its underlying mechanism. We constructed subcutaneous melanoma models to carry out the following experiments. The cells were transfected with a series of miR-374 mimics, miR-374 inhibitors or siRNA against TYR. Dual luciferase reporter gene assay was used for the verification of the targeting relationship between miR-374 and TYR. Reverse transcription quantitative polymerase chain reaction and western blot analysis were conducted to determine the expression of miR-374, TYR, ß-catenin, B-cell leukaemia 2 (Bcl-2), Bcl-2 associated X protein (Bax), Low-density lipoprotein receptor-related protein 6 (LRP6), Leucine-rich repeat G protein-coupled receptor 5 (LGR5) and CyclinD1. Cell proliferation, migration, invasion, cell cycle distribution and apoptosis were evaluated using cell counting kit-8 assay, scratch test, transwell assay and flow cytometry respectively. TYR was proved as a putative target of miR-374 as the evidenced by the result. It was observed that up-regulated miR-374 or down-regulated TYR increased expression of Bax and decreased expressions of TYR, ß-catenin, LRP6, Bcl-2, CyclinD1 and LGR5, along with diminished cell proliferation, migration, invasion and enhanced apoptosis. Meanwhile, cells with miR-374 inhibitors showed an opposite trend. These findings indicated that up-regulated miR-374 could inhibit the expression of TYR to suppress cell proliferation, migration, invasion and promote cell apoptosis in melanoma cells by inhibiting the Wnt signalling pathway.

CRISPR/dCas9-mediated transcriptional improvement of the biosynthetic gene cluster for the epothilone production in Myxococcus xanthus.

BACKGROUND: The CRISPR/dCas9 system is a powerful tool to activate the transcription of target genes in eukaryotic or prokaryotic cells, but lacks assays in complex conditions, such as the biosynthesis of secondary metabolites. RESULTS: In this study, to improve the transcription of the heterologously expressed biosynthetic genes for the production of epothilones, we established the CRISPR/dCas9-mediated activation technique in Myxococcus xanthus and analyzed some key factors involving in the CRISPR/dCas9 activation. We firstly optimized the cas9 codon to fit the M. xanthus cells, mutated the gene to inactivate the nuclease activity, and constructed the dCas9-activator system in an epothilone producer. We compared the improvement efficiency of different sgRNAs on the production of epothilones and the expression of the biosynthetic genes. We also compared the improvement effects of different activator proteins, the ω and α subunits of RNA polymerase, and the sigma factors σ54 and CarQ. By using a copper-inducible promoter, we determined that higher expressions of dCas9-activator improved the activation effects. CONCLUSIONS: Our results showed that the CRISPR/dCas-mediated transcription activation is a simple and broadly applicable technique to improve the transcriptional efficiency for the production of secondary metabolites in microorganisms. This is the first time to construct the CRISPR/dCas9 activation system in myxobacteria and the first time to assay the CRISPR/dCas9 activations for the biosynthesis of microbial secondary metabolites.

Effects of transcriptional mode on promoter substitution and tandem engineering for the production of epothilones in Myxococcus xanthus.

Promoter optimization is an economical and effective approach to overexpress heterologous genes and improve the biosynthesis of valuable products. In this study, we swapped the original promoter of the epothilone biosynthetic gene cluster in Myxococcus xanthus with two endogenous strong promoters P pilA and P groEL1 , respectively, which, however, decreased the epothilone production ability. The transcriptional abilities by the two promoters were found to be bloomed in the growth stage but markedly decreased after the growth, whereas the original promoter P epo functioned majorly after the exponential growth stage. Tandem repeat engineering on the original promoter P epo remarkably increased epothilone production. The tandem promoter exerted similar expressional pattern as P epo did in M. xanthus. We demonstrated that differential transcriptional modes markedly affected the efficiency of promoters in controlling the gene expressions for the production of the secondary metabolite epothilones. Our study provides an insight into exploiting powerful promoters to produce valuable secondary metabolites, especially in host with limited known promoters.

A Sample and Sensitive HPLC-MS/MS Method for Simultaneous Determination of Ziyuglycoside I and Its Metabolite Ziyuglycoside II in Rat Pharmacokinetics.

Ziyuglycoside I (ZGS1) is a promising drug candidate for the treatment of leucopenia. Currently, information on ZGS1 and its in vivo metabolite ziyuglycoside II (ZGS2) is limited. The objective of this study was to investigate the pharmacokinetics, tissue distribution, and excretion of ziyuglycoside I (ZGS1) and its metabolite ziyuglycoside II (ZGS2) in rats. In our study, a simple and sensitive high-performance liquid chromatography-mass spectrometry (HPLC-MS/MS) method was established for simultaneous determination of ZGS1 and its metabolite for Sprague-Dawley rat pharmacokinetics studies. The method was validated following internationally-approved guidelines. The results presented in this study indicated that subcutaneous administration of ZGS1 prolonged its extension time and increased the area under the curve (AUC0-t) of ZGS2 during 0 to t minutes. In summary, in this study, the pharmacokinetic characteristics of ZGS1 and its metabolite ZGS2 were defined and its tissue distribution, and excretion in rats were described. Our finding may be beneficial for leucopenia drug that focus on ZGS1.

A bacterial negative transcription regulator binding on an inverted repeat in the promoter for epothilone biosynthesis.

BACKGROUND: Microbial secondary metabolism is regulated by a complex and mostly-unknown network of global and pathway-specific regulators. A dozen biosynthetic gene clusters for secondary metabolites have been reported in myxobacteria, but a few regulation factors have been identified. RESULTS: We identified a transcription regulator Esi for the biosynthesis of epothilones. Inactivation of esi promoted the epothilone production, while overexpression of the gene suppressed the production. The regulation was determined to be resulted from the transcriptional changes of epothilone genes. Esi was able to bind, probably via the N-terminus of the protein, to an inverted repeat sequence in the promoter of the epothilone biosynthetic gene cluster. The Esi-homologous sequences retrieved from the RefSeq database are all of the Proteobacteria. However, the Esi regulation is not universal in myxobacteria, because the esi gene exists only in a few myxobacterial genomes. CONCLUSIONS: Esi binds to the epothilone promoter and down-regulates the transcriptional level of the whole gene cluster to affect the biosynthesis of epothilone. This is the first transcription regulator identified for epothilone biosynthesis.

Increasing on-target cleavage efficiency for CRISPR/Cas9-induced large fragment deletion in Myxococcus xanthus.

BACKGROUND: The CRISPR/Cas9 system is a powerful tool for genome editing, in which the sgRNA binds and guides the Cas9 protein for the sequence-specific cleavage. The protocol is employable in different organisms, but is often limited by cell damage due to the endonuclease activity of the introduced Cas9 and the potential off-target DNA cleavage from incorrect guide by the 20 nt spacer. RESULTS: In this study, after resolving some critical limits, we have established an efficient CRISPR/Cas9 system for the deletion of large genome fragments related to the biosynthesis of secondary metabolites in Myxococcus xanthus cells. We revealed that the high expression of a codon-optimized cas9 gene in M. xanthus was cytotoxic, and developed a temporally high expression strategy to reduce the cell damage from high expressions of Cas9. We optimized the deletion protocol by using the tRNA-sgRNA-tRNA chimeric structure to ensure correct sgRNA sequence. We found that, in addition to the position-dependent nucleotide preference, the free energy of a 20 nt spacer was a key factor for the deletion efficiency. CONCLUSIONS: By using the developed protocol, we achieved the CRISPR/Cas9-induced deletion of large biosynthetic gene clusters for secondary metabolites in M. xanthus DK1622 and its epothilone-producing mutant. The findings and the proposals described in this paper were suggested to be workable in other organisms, for example, other Gram negative bacteria with high GC content.

Isolation and characterisation of the epothilone gene cluster with flanks from high alkalotolerant strain Sorangium cellulosum (So0157-2).

Epothilones are cytotoxic macrolactones having auspicious anti-tumorous activities, but merely produced by rare Sorangium strains. Here, we have focused on the epothilone gene cluster from special niche bacterial strain, S. cellulosum So0157-2. Therefore, we have isolated a high pH tolerant S. cellulosum strain So0157-2 and characterized the epothilones gene cluster and its flanks by cosmid/fosmid libraries preparation and sequencing. The assembly spanned 94,459 bp and consisted of 56,019 bp core region. Remarkably, the core as well as upstream 420 bp and downstream 315 bp were highly conserved, while further neighboring regions varied extremely. Transposase traces were identified near the core of clusters, supporting that the transposon-mediated transgenesis is a naturally evolved strategy for the cluster's dissemination. A predicted neighboring esterase gene was identified as a potential epothilone-resistance gene preventing self-toxicity. Novel modification or regulatory genes, a multi-position-cyclo releasing gene and their relationship with corresponding analogs were identified in strain So0157-2. These findings open the door to discover additional, naturally evolved epothilone-related genes for significant applications in industrial as well as clinical sector.

Mechanisms involved in the functional divergence of duplicated GroEL chaperonins in Myxococcus xanthus DK1622.

The gene encoding the GroEL chaperonin is duplicated in nearly 30% of bacterial genomes; and although duplicated groEL genes have been comprehensively determined to have distinct physiological functions in different species, the mechanisms involved have not been characterized to date. Myxococcus xanthus DK1622 has two copies of the groEL gene, each of which can be deleted without affecting cell viability; however, the deletion of either gene does result in distinct defects in the cellular heat-shock response, predation, and development. In this study, we show that, from the expression levels of different groELs, the distinct functions of groEL1 and groEL2 in predation and development are probably the result of the substrate selectivity of the paralogous GroEL chaperonins, whereas the lethal effect of heat shock due to the deletion of groEL1 is caused by a decrease in the total groEL expression level. Following a bioinformatics analysis of the composition characteristics of GroELs from different bacteria, we performed region-swapping assays in M. xanthus, demonstrating that the differences in the apical and the C-terminal equatorial regions determine the substrate specificity of the two GroELs. Site-directed mutagenesis experiments indicated that the GGM repeat sequence at the C-terminus of GroEL1 plays an important role in functional divergence. Divergent functions of duplicated GroELs, which have similar patterns of variation in different bacterial species, have thus evolved mainly via alteration of the apical and the C-terminal equatorial regions. We identified the specific substrates of strain DK1622's GroEL1 and GroEL2 using immunoprecipitation and mass spectrometry techniques. Although 68 proteins bound to both GroEL1 and GroEL2, 83 and 46 proteins bound exclusively to GroEL1 or GroEL2, respectively. The GroEL-specific substrates exhibited distinct molecular sizes and secondary structures, providing an encouraging indication for GroEL evolution for functional divergence.

[Pharmacokinetics and tissue distribution of α-hederin sodium salt in rats].

To study the pharmacokinetics and tissue distribution characteristics of α-hederin sodium salt in rats. 100 mg•kg⁻¹ α-hederin sodium salt was given to the rats by intragastric administration, and LC-MS/MS method was used to determine its concentration at different time in plasma and tissues. Plasma and tissue samples were treated with methanol protein deposition method. Main pharmacokinetic parameters were as follows： tmax (0.97±1.23) h, Cmax (222.53±57.28) µg•L⁻¹, AUC0-t (1 262±788.9) h•µg•L⁻¹, T1/2 (17.94±9.50) h. α-hederin can be detected in heart, liver, spleen, lung, kidney, brain, muscle and adipose. The results showed that α-hederin sodium salt was absorbed fast and eliminated slowly in rats after oral administration. It was widely distributed in body tissues and livers kept the highest concentrations among various tissues at different time, so it can be speculated that α-hederin may have certain targeting property on livers.

Allopatric integrations selectively change host transcriptomes, leading to varied expression efficiencies of exotic genes in Myxococcus xanthus.

BACKGROUND: Exotic genes, especially clustered multiple-genes for a complex pathway, are normally integrated into chromosome for heterologous expression. The influences of insertion sites on heterologous expression and allotropic expressions of exotic genes on host remain mostly unclear. RESULTS: We compared the integration and expression efficiencies of single and multiple exotic genes that were inserted into Myxococcus xanthus genome by transposition and attB-site-directed recombination. While the site-directed integration had a rather stable chloramphenicol acetyl transferase (CAT) activity, the transposition produced varied CAT enzyme activities. We attempted to integrate the 56-kb gene cluster for the biosynthesis of antitumor polyketides epothilones into M. xanthus genome by site-direction but failed, which was determined to be due to the insertion size limitation at the attB site. The transposition technique produced many recombinants with varied production capabilities of epothilones, which, however, were not paralleled to the transcriptional characteristics of the local sites where the genes were integrated. Comparative transcriptomics analysis demonstrated that the allopatric integrations caused selective changes of host transcriptomes, leading to varied expressions of epothilone genes in different mutants. CONCLUSIONS: With the increase of insertion fragment size, transposition is a more practicable integration method for the expression of exotic genes. Allopatric integrations selectively change host transcriptomes, which lead to varied expression efficiencies of exotic genes.

Two new furaldehyde compounds from the rhizomes of Gastrodia elata.

Two new compounds 5-[4'-(4″-hydroxybenzyl)-3'-hydroxybenzyloxymethyl]-furan-2-carbaldehyde (1) and 5-[4'-(4″-hydroxybenzyl)-3'-hydroxybenzyl]-furan-2-carbal-dehyde (2), together with two known 5-(4-hydroxbenzyloxymethyl)-furan-2-carbaldehyde] (3) and 5-(hydroxymethyl)-2-furaldehyde (4), were isolated from the rhizome of Gastrodia elata. Their structures were elucidated by spectroscopic analysis and comparison of their spectral data with those reported previously. All compounds exhibited weak or no cytotoxicity against human colon carcinoma cell line (HT-29) and human chronic myelogenous leukemia cell line (K-562).

The mutual interactions based on amphipathic tetraoxacalix[2]arene[2]triazine: recognition cases of anion and cation investigated by a computational study.

The nature of anion···π (anion X1-4(-) = SCN(-), PF6(-), BF4(-) and NO3(-), respectively) interactions with electron-deficient and cavity self-tunable macrocyclic host tetraoxacalix[2]arene[2]triazine 1 as electron-acceptor (J. Am. Chem. Soc., 2013, 135, 892) have been theoretically investigated with the density functional theory (B3LYP, M06-2X, M06-L, M06, M05-2X, M05, DFT-D3) and the second-order Møller-Plesset perturbation theory (MP2) using a series of basis sets. The binding energies calculated are in good quantitative agreement with the experiments. The LMO-EDA (local molecular orbital energy decomposition analysis) results show that the major contributors of anion···π are electrostatic. The alkali metal cations M(+) (Na(+), K(+)) and alkaline earth metal cations M(2+) (Mg(2+), Ca(2+)) can also interact with 1 and, the cation···π binding of M(2+)···1 is stronger than that of M(+)···1, as well as their strength is gradually decreased along with an increase in the radius of M(+,2+). The investigation of interplay between the anion···π and the cation···π shows that the interactions among three-body, X(-), 1 and M(+) is varied with different phases. The polar solvent can strongly reduce the strength of the interaction, and the more increased the solvent polarity, the more reduced is the binding energy.

Crystal structure of catena-poly[[di-aqua(4,5-di-aza-fluoren-9-one-κ(2) N,N')cadmium]-µ-2-hydroxy-5-sulfonato-benzoato-κ(3) O (1),O (1'):O (5)].

In the polymeric title compound, [Cd(C7H4O6S)(C11H6N2O)(H2O)2] n , the Cd(2+) atom is seven-coordinated by two water O atoms, by three O atoms from two 2-hy-droxy-5-sulfonato-benzoate (Hssal(2-)) ligands and by two N atoms from a 4,5-di-aza-fluoren-9-one (Dafo) ligand in a distorted penta-gonal-bipyramidal geometry. The Cd(2+) atoms are monodentately coordinated by the sulfonate group of one Hssal(2-) ligand and bidentately coordinated by the carboxyl-ate group of another Hssal(2-) ligand, generating zigzag chains running parallel to [010]. The chains are linked by O-H⋯O hydrogen bonds into a three-dimensional architecture.

Crystal structure of poly[µ6-adipato-di-aquadi-µ2-oxalato-didysprosium(III)].

In the title coordination polymer, [Dy2(C6H8O4)(C2O4)2(H2O)2] n , the asymmetric unit consists of one Dy(3+) cation, one half of an adipate anion, two halves of oxalate anions and one coordinating water mol-ecule. The adipate and oxalate ions are located on centres of inversion. The Dy(3+) cation has a distorted tricapped trigonal-prismatic geometry and is coordinated by nine O atoms, four belonging to three adipate anions, four to two oxalate anions and one from an aqua ligand. The cations are bridged by adipate ligands, generating a two-dimensional network parallel to (010). This network is further extended into three dimensions by coordination of the rigid oxalate ligands and is further consolidated by O-H⋯O hydrogen bonds. A part of the adipate anion is disordered over two positions in a 0.75:0.25 ratio.

[The Effecacy and Safety of Daratumumab Based Regimens in Relapsed/Refractory Multiple Myeloma: A Single-Center Real-World Data Analysis].

OBJECTIVE: To investigate the efficacy and safety of daratumumab based regimens in relapse and/or refractory multiple myeloma (RRMM) in the real world, as well as the impact of daratumumab on stem cell collection and engraftment. METHODS: The clinical data of patients with RRMM who received daratumumab in hematology department of the First Affiliated Hospital of Xiamen University from February 2019 to March 2023 and had evaluable efficacy were retrospective analysis. RESULTS: All 43 RRMM patients were treated with daratumumab-based combination regimens, including Dd, DVd, DRd, Dkd, DId, and Dara-DECP. With median follow-up time 10.1 (2.1-36.6) months, the best overall response rate (ORR) was 74.4% and a best complete response rate (CR) was 25.6%. 1-year overall survival rate (OS) was 84.5%. The most common severe hematologic adverse events (Grade>3) are 3/4 grade leukopenia（18.6%）, and the most common severe non-hematologic adverse events were infusion-related reactions (IRRs， 20.9%) and infections（7.0%）. Multivariate prognostic analysis showed that extramedullary infiltration was an independent adverse prognostic factor affecting OS （P =0.004）. The use of daratumumab has no effect on stem cell collection, or engraftment. CONCLUSION: Daratumumab is safe and effective in RRMM.

Novel PIKfyve/Tubulin Dual-target Inhibitor as a Promising Therapeutic Strategy for B-cell Acute Lymphoblastic Leukemia.

OBJECTIVE: In B-cell acute lymphoblastic leukemia (B-ALL), current intensive chemotherapies for adult patients fail to achieve durable responses in more than 50% of cases, underscoring the urgent need for new therapeutic regimens for this patient population. The present study aimed to determine whether HZX-02-059, a novel dual-target inhibitor targeting both phosphatidylinositol-3-phosphate 5-kinase (PIKfyve) and tubulin, is lethal to B-ALL cells and is a potential therapeutic for B-ALL patients. METHODS: Cell proliferation, vacuolization, apoptosis, cell cycle, and in-vivo tumor growth were evaluated. In addition, Genome-wide RNA-sequencing studies were conducted to elucidate the mechanisms of action underlying the anti-leukemia activity of HZX-02-059 in B-ALL. RESULTS: HZX-02-059 was found to inhibit cell proliferation, induce vacuolization, promote apoptosis, block the cell cycle, and reduce in-vivo tumor growth. Downregulation of the p53 pathway and suppression of the phosphoinositide 3-kinase (PI3K)/AKT pathway and the downstream transcription factors c-Myc and NF-κB were responsible for these observations. CONCLUSION: Overall, these findings suggest that HZX-02-059 is a promising agent for the treatment of B-ALL patients resistant to conventional therapies.