Trichostatin C attenuates TNFα-induced inflammation in endothelial cells by up-regulating Krüppel-like factor 2 / 药学学报

Krüppel-like transcription factor 2 (KLF2) plays a key regulatory role in endothelial inflammation, thrombosis, angiogenesis and macrophage inflammation and polarization, and up-regulation of KLF2 expression has the potential to prevent and treatment atherosclerosis. In this study, trichostatin C (TSC) was obtained from the secondary metabolites of rice fermentation of Streptomyces sp. CPCC 203909 as a KLF2 up-regulator by using a high throughput screening model based on a KLF2 promoter luciferase reporter assay. TSC significantly inhibited the adhesion of tumor necrosis factor-α (TNFα) induced monocytes (THP-1) to human umbilical vein endothelial cells (HUVECs). Western blot results showed that TSC decreased TNFα induced the protein expression increase of vascular cell adhesion molecule-1 (VCAM-1), and thereby inhibited endothelial inflammation. The results of histone deacetylase (HDAC) overexpression and molecular docking experiments showed that TSC upregulated the expression of KLF2 by inhibiting subtypes of HDAC 4/5/7. In conclusion, this study suggests that TSC up-regulates the expression of KLF2 through inhibiting HDAC 4/5/7 and thus inhibits TNFα induced endothelial inflammation, and it has the potential to prevent and treat atherosclerosis.

Bioassay of ansamitocin by Trichoderma plate / 药学学报

This paper describes a bioassay method for the determination of ansamitocin titers. A fungal strain sensitive to ansamitocin was classified to the genus Trichoderma based on phylogenetic analysis of its ITS sequence, and designated as Trichoderma CPCC 400749. PDA plates of Trichoderma CPCC 400749 were prepared to assay ansamitocin titers of Actinosynnema pretiosum ATCC 31565. The titers were consistent with those determined by HPLC. The bioassay method may have the potential use in high-throughput screening for Actinosynnema pretiosum mutants with improved ansamitocin titers.

Metabolism of saponins from traditional Chinese medicines: a review / 药学学报

Saponins are important components in traditional Chinese medicine (TCM) with significant biological activities, which could be divided into triterpenoid saponins and steroidal saponins according to structures of the aglycone skeletons. This article reviews the in vivo metabolic pathways of some typical natural saponins such as ginsenosides, licorice saponins, saikosaponins, timosaponins and diosgenin glycosides. Saponins often show poor absorbance after oral administration. The in vivo metabolism of saponins generally contain two steps. These compounds usually undergo hydrolysis in stomach and gut. Then they are absorbed into blood and metabolized in liver. The secondary glycosides and the aglycones produced in gastrointestinal tract often show higher bioavailability and better bioactivity, while downstream metabolites in liver are mainly produced by phase I metabolism. Clarification of the in vivo metabolism of bioactive saponins is helpful for the understanding of the effective ingredients in TCM, as well as the discovery of new drugs from natural products.

A new benzamide derivative from rice fermentation of Streptomyces sp. CPCC 202950 / 中国中药杂志

Eight compounds were isolated from the rice fermentation of Streptomyces sp. CPCC 202950 by a combination of various chromatographic techniques including column chromatography over silica, Sephadex LH-20, flash C₁₈, and reversed-phase HPLC. Their structures were identified as 3-[(3'-amino-3'-oxoprop-1'-en-2'-yl)oxy]benzamide (1), m-hydroxybenzamide (2), leptosphaepin (3), 5-methyluracil (4), feruloylamide (5), p-hydroxyphenylacetoamide (6), vanillamide (7), cyclo (L-val-L-ala) (8). Among them, 1 was a new benzamide analogue, and 2 was a new natural product. In the preliminary assays, none of the compounds 1-8 exhibited obvious inhibition of HIV-1 protease activity, and toxic with the Hela, HepG2, and U2OS cells. (IC₅₀ > 10 μmol•L⁻¹).

Identification of 3-demethylchuangxinmycin from Actinoplanes tsinanensis CPCC 200056 / 药学学报

Chuangxinmycin (CM) from Actinoplanes tsinanensis was an antibiotic discovered by Chinese scientists about 40 years ago. It contains a new heterocyclic system of indole fused with dihydrothiopyran, whose biosynthetic mechanism remains unclear. CM is used as an oral medicine in the treatment of bacterial infections in China. The simple structure makes CM as an attractive candidate of structure modification for improvement of antibacterial activity. Recently, we analyzed the secondary metabolites of Actinoplanes tsinanensis CPCC 200056, a CM producing strain, as a natural CM analogue. We discovered the first natural CM analogue 3-demethylchuangxinmycin (DCM) as a new natural product. Compared to CM, DCM exhibited a much weaker activity in the inhibition of the bacterial strains tested. The finding provides valuable information for the structure-activity relationship in the biosynthesis of CM.

Identification of 3-demethylchuangxinmycin from Actinoplanes tsinanensis CPCC 200056 / 药学学报

Chuangxinmycin (CM) from Actinoplanes tsinanensis was an antibiotic discovered by Chinese scientists about 40 years ago. It contains a new heterocyclic system of indole fused with dihydrothiopyran, whose biosynthetic mechanism remains unclear. CM is used as an oral medicine in the treatment of bacterial infections in China. The simple structure makes CM as an attractive candidate of structure modification for improvement of antibacterial activity. Recently, we analyzed the secondary metabolites of Actinoplanes tsinanensis CPCC 200056, a CM producing strain, as a natural CM analogue. We discovered the first natural CM analogue 3-demethylchuangxinmycin (DCM) as a new natural product. Compared to CM, DCM exhibited a much weaker activity in the inhibition of the bacterial strains tested. The finding provides valuable information for the structure-activity relationship in the biosynthesis of CM.

Chemical constituents from culture of Streptomyces sp. CPCC 202950 / 中国中药杂志

Eleven compounds were isolated from the culture of Streptomyces sp. CPCC 202950 by a combination of various chromatographic techniques including column chromatography over macroporous resin HP-20, MCI, and reversed-phase HPLC. Their structures were identified as 1H-pyrrole-2-carboxamide(1),5'-deoxy-5'-methylthioinosine(2), vanillamide(3), trans-3-methylthioacrylamide(4), 1,2,3,4-Tetraydro-1H-pyrido[3,4-b]indole-3-carboxylic acid(5), cyclo(L-pro-L-tyr) (6), N-[2-(4-hydroxyphenyl)]ethylacetamide(7), benzamide (8), cyclo ('L-leucyl-trans-4-hydroxy-L-proline)(9), cyclo-(Phe-Gly) (10), and tryptophan (11). Among them, compounds 1 and 2 were new natural products. In the preliminary assays, none of the compounds exhibited obvious inhibition of HIV-1 protease activity (IC50 > 10 micromol x L(-1)).

A new lactone derivative from plant endophytic fungus Periconia sp. F-31 / 中国中药杂志

To investigate the secondary metabolites of endophytic fungi Pericinia sp. F-31. Column chromatography on silica gel, Sephadex LH-20 and semi-preparative HPLC were used to separate and purify the compounds. Two compounds were isolated from the fermentation broth of Periconia sp. Their structures were identified as 5-(1-hydroxyhexyl) -6-methyl-2H-pyran-2-one (1) and 2-(3-hydroxy-4-methylphenyl) -propanoic acid (2). Compound 1 was a new lactone compound, compound 2 was new natural product, and the NMR data of compound 2 was reported for the first time.

A novel trichostatin analogue culture of Streptomyces sp. CPCC 203909 / 中国中药杂志

By using a cell-based high throughput screening model for the CLA-1 up-regulator, Streptomyces 203909 was found to produce up-regulator of CLA-1. A novel trichostatin analogue was isolated from the rice fermentation of Streptomyces sp. CPCC 203909by a combination of various chromatographic techniques including column chromatography (CC) over silica gel, flash C18 CC, and reversed-phase HPLC. Its structure was identified as (-)-(R,2E,4Z)-7-[(4'-dimethylamino) phenyl]-4,6-dimethyl-7-oxohepta-2,4-dienoyl-L-glutamine (1) by the spectroscopic and chemical methods, and combination with the CD spectroscopy and Marfey's method. In the prelimi- nary assays, Compound 1 showed cytotoxicity against human embryonic kidney 293 cell line with IC50 value 35.3 [µmol · L(-1).

Effects of class I( phosphatidylinositol-3-kinases inhibitor on gastric cancer cell xenografts in nude mice / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To investigate the effect of recombinant adenovirus (phosphatidylinositol-3-kinases(PI3K)(I()-RNAi-AD which blocks the class I( PI3K signaling pathway on gastric carcinoma cells xenografts in nude mice.</p><p><b>METHODS</b>Subcutaneous tumor models of nude mice were established with SGC7901 cells and randomly divided into PI3K(I()-RNAi-AD group, NC-RNAi-GFP-AD group and control group. The tumor size and the inhibitory rate of tumor growth on days 3, 6, and 9 after cell transplantation were measured. The expression of TNF-α, COX2, P53, PCNA, E-cadherin and nm23/DNPK in tumor tissues were detected by immunohistochemistry.</p><p><b>RESULTS</b>Tumor growth was significantly inhibited in the PI3K(I()-RNAi-AD group(14.2%, 21.0%, and 28.1%) on days 3, 6, 9 compared with NC-RNAi-GFP-AD group(1.3%, 1.9%, and 2.0%, all P<0.05). The expressions of TNF-α, P53, E-cadherin and nm23/DNPK were up-regulated, and the expressions of COX2 and PCNA were down-regulated in the PI3K(I()-RNAi-AD group by immunohistochemical staining(all P<0.05).</p><p><b>CONCLUSIONS</b>PI3K(I()-RNAi-AD can inhibit the growth of SGC7901 cell transplantation tumor in vivo in nude mice by inhibiting cell growth, reducing the capacity of tumor invasion and inhibiting tumor angiogenesis.</p>

Effects of combined therapy of LY294002 and SN50 on nude mice model with gastric cancer / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To investigate the effect of phosphatidylinositol 3-kinase inhibitor LY294002 combined with NF-κB P65 nuclear translocation inhibitor SN50 on the tumor cell growth and apoptosis using a nude mouse model of gastric cancer.</p><p><b>METHODS</b>Human gastric cancer cell strain SGC7901 was transplanted subcutaneously to nude mice to establish tumor models. Model mice were randomly divided into the control group, the LY294002 treatment group, the SN50 treatment group, and the LY294002+SN50 treatment group, with 5 in each group. After being treated for 10 days, the inhibition rate of tumor growth was ascertained by measuring the size of tumor. Immunohistochemical method was used to detect the expression levels of Bcl-2, P53 and Bax proteins and transmission electron microscopy to investigate the apoptosis of tumor cells.</p><p><b>RESULTS</b>On the 10th day after treatment, the inhibition rate of gastric cancer cellular growth in the LY294002+SN50 group was (49.2±2.5)%, which was significantly higher than that in the LY294002 group(29.4±1.5)% and SN50 group (19.7±1.6)%(P<0.05). In comparison with the other two groups, LY294002+SN50 group exhibited more severe apoptosis, with expression of Bcl-2 decreased and that of P53 and Bax increased more significantly(P<0.05).</p><p><b>CONCLUSION</b>LY294002 combined with SN50 inhibits the growth of SGC7901 transplanted tumor and aggravates the apoptosis of gastric cancer cells in nude mice model.</p>

Establishment and drug susceptibility test of isoniazid resistant Mycobacterium smegmatis / 药学学报

With the emergence of drug resistant tuberculosis, it is very urgent to find novel anti-tuberculosis drugs, especially novel anti-drug-resistant tuberculosis drugs. Because of the slow growth and the need to work in a biosafty environment of Mycobacterium tuberculosis, the development of evaluation of drug effect is severely impeded. In order to solve these issues, non-pathogenic fast-growing Mycobacterium smegmatis is introduced as test organism. The inhA is one of a target of isoniazid (INH) overexpression or mutation of this gene in Mycobacterium tuberculosis conferring resistant to INH. A recombinant plasmid bearing inhA was constructed and electroporated into Mycobacterium smegmatis, using shuttle expression vector pMV261. Transformants were induced to express a protein of inhA, identified by SDS-PAGE. Results show that Mycobacterium smegmatis containing inhA plasmids exhibited 100-fold or greater increased resistance to INH, but it conferred no increased resistance to others first-line anti-tuberculosis drugs. Resazurin microtiter assay plate testing of Mycobacterium smegmatis susceptibility to drugs is a rapid, simple, and inexpensive method and could decrease color background of drugs by detecting fluorescence. It will be benefit for high-throughout screening of drugs of anti-isoniazid-resistant Mycobacteria.

Bacterial Protein Secretion Pathway with SecA as a Motor / 微生物学通报

There are one third of synthesized proteins must be secreted to the cell surface or to the surrounding environment to acquire their native functional state. Most of them are exported by Sec translocase (secretion pathway). Sec translocase consists of a membrane embedded protein-conducting channel, termed SecYEG and a peripherally associated motor domain, the ATPase SecA. The SecDFyajC heterotrimeric membrane protein complex can facilitates protein translocation. SecB is a molecular chaperone that functions in the protein translocation pathway. SecM (secretion monitor) encoded by the 5' region of the secM-secA mRNA, which elongation arrest is required for upregulated expression of SecA. The signal sequence in the N terminus of the nascent peptide is first recognized by the signal recognition particle (SRP). SecB, the Sec-system-specific chaperone, channels the preprotein to the Sec translocation pathway and, ad- ditionally, actively targets the bound precursor to the translocase by its ability to bind SecA. The preprotein-bearing SecA then binds to the membrane, at a high-affinity SecA-binding site, SecYEG, which constitutes a channel for polypeptide movement. Continued translocation requires cycles of ATP hydrolysis bySecA, which is thought to occur in a step-wise fashion with a step of 20~30 amino acid residues.

The Establishment and Application of Anti-Pseudomonas aeruginosa Cell-based Screening Model Targeting to SecA / 微生物学通报

The most of secreted proteins are exported by Sec translocase (secretion pathway). SecA ATPase is one of the most important subunit in the Sec translocase, which is preprotein translocase nanomotor that undergo membrane insertion and deinsertion to drive preprotein across the bacterial inner membrane, and SecA is indispensable to bacteria. It should be presumed that the compound which inhibits the activity of SecA ATPase probably can be used as the candidate of bactericide. A secA gene from Pseudomonas aerugi- nosa PAO1 was amplified and expressed in Escherichia coli BL21.19 (secA13). It has been shown that the wild-type SecA of Pseudomonas aeruginosa could fully complement the E. coli amber (secA13) mutant at the non-permissive temperature. So a cell level screening model targeting on SecA was established based on the above result. The inhibition of PaSecA ATPase activity was applied to validate the specificity of the cell-based method. Two positive samples based on both of cell and enzyme activities will be further studied.

Drug screening model acting on out-membrane protein OprM in pseudomonas aeruginosa efflux pump system / 中国医学科学院学报

<p><b>OBJECTIVE</b>To establish an efflux pump inhibitor screening model with the out-membrane protein OprM in Pseudomonas aeruginosa efflux pump system as the target point.</p><p><b>METHODS</b>Efflux pump out-membrane protein gene oprM was obtained from standard Pseudomonas aeruginosa PA01 strain. Expression of OprM protein was induced in E. coli strain HS151 with T-easy vector as the cloning vector, and pMMB67EH as the expression vector. In order to evaluate the function of OprM protein, we measured intracellular tetracycline concentrations with liquid scintillation counter, measured the diameters of bacteriostatic circles with paper disc, and then established a screening model accordingly.</p><p><b>RESULTS</b>OprM protein was highly expressed. Using Pseudomonas aeruginosa as the main detecting bacteria, we established a drug screening model acting on OprM. A total of 1 600 microbial fermentation samples were screened with this model, among which 56 positive strains were found, with a positive rate of 3.5%.</p><p><b>CONCLUSION</b>OprM plays an important role in drug efflux. The established model has good specificity and maneuverability.</p>

THE ISOLATION AND IDENTIFICATION OF ACTINOBACTERIA / 微生物学通报

The lineage-Actinobacteria class nov.comprises organisms with a DNA base composition which generally is above 50% G+C (with a few exceptions).We set up a method that has been used in isolating Actinobacteria and Actinomycetes. We added 25?g/mL Nalidixic acid and 25?g/mL Aztreonam into isolation media to inhibit the other bacteria and 20?g/mL Benlete to inhibit fungi.We used fluorescent in situ hybridization to identi 1fy Actinobacteria. Using the four probes,PA-1,PA-2,PHGC and PNHGC,we made the identification on the 31 strains of the 56 gram-positive bacteria randomly selected and got 22 positive results,6 negative results and 3 ambiguous results.It was showed that the results of G+C content determination and FISH method were identical.Among 31 strain,there were 24 strains of Actinobacteria,the rate was 77.4%.This proved the isolation and FISH identification methods were effective and reliable.

PROGRESS IN RESEARCH OF MICROORGANISMS OF NATURAL ENVIRONMENTS IN THE VIABLE BUT NON-CULTURABLE STATE / 微生物学通报

At the beginning of the 1980s, a concept of viable but non-culturable(VBNC) was suggested. VBNC is a survival strategy adopted by microorganisms when they are exposed to environmental stress. This article try to make a summary of research of the conditions of VBNC formation, recovery of culturability and methods of VBNC cells detection. In addition, introduces the first growth factor of microorganisms-Rpf.

Study of Methods to Isolate Viable but Non-culturable Microorganisms from Natural Environments / 微生物学通报

This project is targeted on exploring some improving approaches to isolate and culture the microorganisms which are difficult to be isolated and cultured through the conventional ways. The results showed that betaine, sodium pyruvate, SOD and catalase are helpful for increasing the total number and variety of isolated strains. A kind of combined method was also used to isolate the micro-colony which can not be seen by naked eyes on the plates. Totally 52 Actinomycetes and 103 bacteria and 17 fungi were obtained from 4 soil samples using the above methods. 4. 325% microorganisms were obtained as positive strains to inhibit the growth of some kinds of test bacteria, which is higher than the percent using generally isolated ones. These microbial natural products may remain an important resource for the drug discovery.