Screening of plant growth-promoting rhizobacteria and its effect on seed germination of Polygonum multiflorum / 中国中药杂志

In this study, the rhizobacteria and actinomycetes of Polygonum multiflorum were screened for the strains with indole acetic acid(IAA)-producing capacity by Salkowski method, the siderophore-producing strains by Chrome Azurol S(CAS) assay, and the strains with inorganic phosphorus-solubilizing capacity by PKO inorganic phosphorus medium. The strains were identified by morphological identification, physiological and biochemical characteristics, and 16 S rDNA sequences. Furthermore, the effect of growth-promoting strains on the seed germination and development of P. multiflorum was tested. The results showed that among 196 strains, two strains F17 and F42 were found to be capable of producing IAA and siderophore and solubilizing inorganic phosphorus simulta-neously. For F17 and F42, the results are listed below: 38.65 and 33.64 mg·L~(-1) for IAA production, 0.85 and 0.49 for siderophore-producing capacities(A_s/A_r), and 1.35 and 1.70 for inorganic phosphorus-solubilizing capacities(D/d), respectively. Comprehensive analysis revealed that strains F17 and F42 were identified as Pseudochrobactrum asacharolyticum and Bacillus aryabhattai, respectively, and both could significantly promote the seed germination of P. multiflorum.

Effects of drought stress on physiological and biochemical and chemical components of Cinnamomum cassia seedlings / 中国中药杂志

Six month old Cinnamomum cassia seedlings were used to simulate drought stress with polyethylene glycol(PEG 6000). The physiological indicators(osmotic substances, antioxidant enzymes, etc.) and chemical components of seedlings under different drought levels and the correlation between the two were studied. The results showed that the chlorophyll content and relative water content decreased gradually with the increase of PGE 6000(0, 5%, 10%, 15%) concentration and time(3, 5, 7 d), while the soluble protein content, soluble sugar content and catalase(CAT) activity increased, but the rising rate slowed down with the time. The activities of peroxidase(POD), superoxide dismutase(SOD), malondialdehyde(MDA) and proline content increased at first and then decreased. The content of coumarin, cinnamaldehyde, cinnamic acid and dimethoxycinnamaldehyde decreased, while the content of cinnamyl alcohol continued to increase.Under drought stress, the fluorescence signals of reactive oxygen species and no contents in roots of C. cassia seedlings were significantly stronger than those of the control.Further correlation analysis showed that coumarin content, di-methoxycinnamaldehyde content and osmoregulation substance content were significantly negatively correlated(P<0.05), cinnamic acid content was significantly negatively correlated with POD and SOD activities(P<0.01).It was found that C. cassia seedlings showed a certain degree of drought tolerance under short-term or mild drought stress, but if the drought exceeded a certain degree, the physiological metabolism of the seedlings would be unbalanced.

Effect of Polygonum multiflorum-Andrographis paniculata intercropping system on rhizosphere soil actinomycetes community structure and diversity of P. multiflorum / 中国中药杂志

To investigate the effect of Polygonum multiflorum-Andrographis paniculata intercropping system on rhizosphere soil actinomycetes of P. multiflorum, the community structure and diversity of soil actinomycetes were studied by using the original soil as the control group and the rhizosphere soil actinomycetes communities of P. multiflorum under monoculture and intercropping systems as the experimental group. In this study 655 221 effective sequences were obtained with an average length of 408 bp. OTU coverage and rarefaction curve showed that the sequencing could represent the real situation of soil actinomycetes. According to the results of alpha diversity analysis, the diversity soil actinomycetes varied as follows: original soil>intercropping soil>monoculture soil. The soil actinomycetes community structure and the relative abundance of dominant genera were significantly changed by both monoculture and intercropping, especially monoculture. OTU clustering and PCA analysis of soil samples showed that all the soil samples were divided into three distinct groups and the original soil was more similar to intercropping soil. In addition, intercropping increased the relative abundance of some beneficial actinomyces, such as Kitasatospora and Mycobacterium, which was beneficial to maintain soil health and reduce the occurrence of soil-borne diseases. The results show that, P. multiflorum-A. paniculata intercropping reduced the change of community structure and the decrease of diversity of soil actinomycetes caused by P. multiflorum monoculture, and made the actinomycete community in rhizosphere soil of P. multiflorum close to the original soil.

Cloning and characterization of UDP-L-rhamnose synthase 1/2 from Fallopia multiflora / 药学学报

UDP-rhamnose is a rhamnose donor in a reaction catalyzed by UDP-rhamnose synthase (RHM), and plays an important role in the biosynthesis of rhamnoside compounds. The current literature suggests that there are only a few genes can encode the corresponding enzymes to participate in UDP-rhamnose biosynthesis in plants. In this study, two RHM genes (FmRHM1 & 2) were first cloned by using the transcriptomic data of Fallopia multiflora (Thunb) Harald and the multidimensional analysis, including bioinformatics, functional identification in vitro and tissue-specific expression analysis. The results showed that the open reading frame (ORF) of FmRHM1 & 2 genes both were 2 013 bp, encode proteins consisting of 670 amino acids with a calculated molecular mass of 75.6 kDa, and the theoretical isoelectric points of 6.20 and 7.19, respectively. Bioinformatic analysis also indicated that FmRHM1 & 2 contained 2 special sequences of GxxGxxG/A and YxxxK. The phylogenetic analysis showed that the FmRHM gene has a high homology with RHM of other species. The results of enzyme activity in vitro revealed that both recombinant FmRHM1 and FmRHM2 have catalytic activities for converting UDP-glucose into UDP-rhamnose. Measurements of tissue-specific expressions showed that the expression levels of FmRHM1 and FmRHM2 were lower in roots. On the contrary, the 2 genes showed significantly high expression in the stems and leaves. In conclusion, we have cloned and characterized the RHM gene function for the first time in F. multiflora. Here we have provided the preliminary data suggesting the need for further research on UDP-rhamnose biosynthesis by microorganisms.

Expression of microRNA-29b2-c cluster is positively regulated by MyoD in L6 cells / 中国医学科学杂志(英文版)

<p><b>OBJECTIVES</b>To evaluate the expression profile of myoD microRNA-29 (miR-29) family in L6 myoblast differentiated to myotube of L6 myotube treated by glucose and insulin, and to further probe the molecular mechanism of myoD regulating the expression of miR-29 clusters.</p><p><b>METHODS</b>The expression of myoD and miR-29 family was detected by using real-time PCR and Western blot analysis. The potential promoter and transcription factors binding sites of miR-29 clusters were predicted by Promoter scan and transcriptional factor search. The promoter sequence of miR-29b1-a and miR-29b2-c cluster was cloned into a luciferase reporter plasmid and the regulatory effect of myoD was analyzed by using dual luciferase reporter assay. Electrophoretic mobility shift assay was further conducted to indicate the binding of myoD on specific sequence. Moreover, overexpression of myoD was achieved by a recombinant adenovirus system (Ad-myoD). L6 cells were infected with Ad-myoD and real-time PCR was conducted to analyze the expression of miR-29b and miR-29c.</p><p><b>RESULTS</b>The expression levels of myoD, miR-29a, miR-29b, and miR-29c were increased in L6 myoblast differentiated to myotube. The expression of myoD, miR-29b, and miR-29c was up-regulated in L6 myotube treated with glucose and insulin, but miR-29a depicted no significant change. Dual luciferase reporter gene assay showed that myoD functioned as a positive regulator of miR-29b2-c expression and myoD could bind to the specific sequence located at the promoter region of miR-29b2-c cluster. Enforced expression of myoD led to a marked increase of miR-29b and miR-29c levels in L6 cells.</p><p><b>CONCLUSION</b>MyoD might act as a crucial regulator of myogenesis and glucose metabolism in muscle through regulating the expression of miR-29b2-c.</p>

PTEN and PDCD4 are bona fide targets of microRNA-21 in human cholangiocarcinoma / 中国医学科学杂志(英文版)

<p><b>OBJECTIVE</b>To investigate the expression profile of microRNA-21 in human cholangiocarcinoma tissues and to validate its bona fide targets in human cholangiocarcinoma cells.</p><p><b>METHODS</b>The expression profile of microRNA-21 in human cholangiocarcinoma tissues and cholangiocarcinoma cell line, QBC939, was evaluated by using real-time PCR analysis. The bona fide targets of microRNA-21 were analyzed and confirmed by dual luciferase reporter gene assay and western blot, respectively. The expressional correlation of microRNA-21 and its targets was probed in human cholangiocarcinoma tissues by using real-time PCR, locked nucleic acid in situ hybridization (LNA-ISH), and immunohistochemistry analysis.</p><p><b>RESULTS</b>Real-time PCR analysis revealed that microRNA-21 expression depicted a significant up-regulation in human cholangiocarcinoma tissues about 5.6-fold as compared to the matched normal bile duct tissues (P<0.05). The dual luciferase reporter gene assay revealed endogenous microRNA-21 in cholangiocarcinoma cell line, QBC939, inhibited the luciferase reporter activities of wild-type PTEN (P<0.01) and PDCD4 (P<0.05) and had no this effect on mutated PTEN and PDCD4. Moreover, loss of microRNA-21 function led to a significant increase of PTEN and PDCD4 protein levels in QBC939 cells. Elevated microRNA-21 levels were accompanied by marked reductions of PTEN and PDCD4 expression in the same cholangiocarcinoma tissue.</p><p><b>CONCLUSION</b>microRNA-21 expression is up-regulated in human cholangiocarcinoma and PTEN, PDCD4 are direct effectors of microRNA-21.</p>

Bio panning of human stem cell factor(2) mimetic peptides from phage displayed random peptide library / 中国医学科学院学报

<p><b>OBJECTIVE</b>To screen human stem cell factor (hSCF) mimetic peptides in vitro with a phage-display random peptide library.</p><p><b>METHODS</b>Phage clones with high hSCF receptor (rc-kit/Ig 1-3)-binding activity was screened from phage-displayed random hepta/dodecapeptide library by phage enzyme-linked immunosorbent assay (ELISA). Phage single DNA was extracted and sequenced. Four kinds of peptide with higher c-Kit/Ig 1-3 binding activity were chosen for synthesis and characterized by using cell proliferation assay with 3-(4,5-dimethylthiazol-2-yl)2,5-diphenyltetrazolium bromide (MTT) method in UT-7 cells.</p><p><b>RESULTS</b>Eleven Ph.D.-C7C clones and eight Ph.D-12 phage clones with high hSCF receptor-binding activity were selected from phage-displayed random hepta/dodecapeptide library, respectively. Sequence analysis showed there were no homologous sequence between hSCF and these screened mimetic peptides except one homologous sequence DPSPHTH found in heptapeptide library. All these four synthesized peptides (CE3, CE16, LE4, and LE20), particularly CE16 and LE20, stimulated UT-7 cell proliferation.</p><p><b>CONCLUSION</b>Four hSCF mimetic peptides were successfully isolated from phage-displayed random peptide library..</p>

Effect of Tuina on oxygen free radicals metabolism in patients with chronic fatigue syndrome / 中国针灸

<p><b>OBJECTIVE</b>To explore the mechanism of Tuina for treatment of chronic fatigue syndrome.</p><p><b>METHODS</b>A total of 90 patients were randomly divided into a Tuina group, a Taijiquan (take exercise) group and a Fluoxetine group, 30 cases in each group. They were treated with Tuina, Taijiquan and Fluoxetine, respectively. After a month, the therapeutic effects and the changes of malondialdehyde (MDA) content and the activity of serum superoxide dismutases (SOD) and serum glutathione peroxidase (GSH-Px) were ohserved.</p><p><b>RESULTS</b>The total effective rate of 93.3% (28/30) in the Tuina group was better than 80.0% (24/30) in the Taijiquan group and 73.3% (22/30) in the Fluoxetine group (both P < 0.05). After treatment, MDA contents in the three groups were all decreased (P < 0.01, P < 0.05), and the activity of SOD. GSH-Px in both the Tuina group and the Fluoxetine group were increased (P < 0.01, P < 0.05), and especially in the Tuina group with a significant difference as compared with the other two groups (P < 0.05, P < 0.01).</p><p><b>CONCLUSION</b>The therapeutic effect of the Tuina group is superior to that of the Taijiquan group and the Fluoxetine group. Tuina can regulate oxygen free radicals metabolism and clean superfluous oxygen free radicals to alleviate fatigue, which may be one of the mechanisms of Tuina in treating chronic fatigue syndrome.</p>

Full-length of human papillomavirus type 18L1 gene optimized using the plant preferred codons and synthesized by overlapping PCR / 南方医科大学学报

<p><b>OBJECTIVE</b>The Human papillomavirus type 18L1 (HPV18L1) gene was synthesized by overlapping PCR after optimization using plant preferred codons.</p><p><b>METHODS</b>The gene sequences of HPV18L1 were obtained from GenBank and analyzed using DNAMAN, Lasergene, Vector NTI and BLAST. The target sequence was selected and modified using plant preferred codons by the Synthetic Gene Designer and JCat (Java Codon Adaptation Tool) with the addition of a His-tag to the C-terminus to construct the full-length modified HPV18L1 (mHPV18L1). mHPV18L1 was divided into 5 large segments, namely LS1 to LS5, with sizes ranging from 204 to 477 bp. Forty-three small oligonucleotide fragments with sizes of 57-59 bp and 6 pairs of primers were designed and synthesized. mHPV18L1 was amplified by overlapping PCR and subcloned into pMD18-T vector. The recombinant plasmid was identified by restriction enzymes digestion and sequencing.</p><p><b>RESULTS</b>mHPV18L1 was successfully assembled using overlapping PCR. The results of digestion with restriction enzymes and PCR amplification confirmed that the recombinant vector pMD18T- mHPV18L1 contained the inserts with expected size of 1749 bp. mHPV18L1 sequence was confirmed by sequencing.</p><p><b>CONCLUSION</b>mHPV18L1 with plant preferred codons and the recombinant vector pMD18T- mHPV18L1 have been obtained.</p>

Establishment of the genotype-specific targets of botulinum neurotoxins types B and E based on reverse genetics / 南方医科大学学报

<p><b>OBJECTIVE</b>To establish the genotype-specific targets plasmids and engineered E.coli strains of botulinum neurotoxins (BoNT) types B and E based on reverse genetics.</p><p><b>METHODS</b>The gene sequences of BoNT were obtained from GenBank and analyzed using DNAMAN, Lasergene, Vector NTI and BLAST. Two target fragments of BoNT/B and BoNT/E were anchored and then synthesized as 5 and 10 short DNA single strands, respectively. The full-length target sequences were amplified by overlapping PCR and subcloned into pMD 18-T vector, and the recombinant plasmids were identified by restriction enzyme digestion and sequencing.</p><p><b>RESULTS</b>Sixty full-length sequences of 4 types of BoNT, namely types A, B, E, and F, were available in GenBank. Two target fragments, BoNT/B of 215 bp and BoNT/E of 360 bp, and their specific primer pairs were anchored after sequence analysis. pMD 18-T-BoNT/B and pMD 18-T-BoNT/E containing these two target sequences were confirmed.</p><p><b>CONCLUSION</b>The engineered plasmids and E.coli stains containing the genotype-specific target fragments of BoNT/B and BoNT/E have been constructed successfully.</p>

Inhibition of human prostate cancer xenograft growth by 125I labeled triple-helix forming oligonucleotide directed against androgen receptor / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The failure of hormone treatment for advanced prostate cancer might be related to aberrant activation of the androgen receptor. We have shown that (125)I labeled triple-helix forming oligonucleotide (TFO) against the androgen receptor gene inhibits androgen receptor expression and cell proliferation of LNCaP prostate cancer cells in vitro. This study aimed at exploring the effects of the (125)I-TFO on prostate tumor growth in vivo using a nude mouse xenograft model.</p><p><b>METHODS</b>TFO was labeled with (125)I by the iodogen method. Thirty-two nude mice bearing LNCaP xenograft tumors were randomized into 4 groups and were intratumorally injected with (125)I-TFO, unlabeled TFO, Na(125)I and normal saline. Tumor size was measured weekly. The tumor growth inhibition rate (RI) was calculated by measurement of tumor weight. The expression of the androgen receptor gene was performed by RT-PCR and immunohistochemical study. The prostate specific antigen (PSA) serum levels were measured by enzyme linked immunosorbent assay. The tumor cell apoptosis index (AI) was detected by TUNEL assay.</p><p><b>RESULTS</b>Tumor measurements showed that tumor development was significantly inhibited by either (125)I-TFO or TFO, with tumor RIs of 50.79% and 32.80% respectively. (125)I-TFO caused greater inhibition of androgen receptor expression and higher AIs in tumor tissue than TFO. Both the tumor weight and the PSA serum levels in (125)I-TFO treated mice ((0.93 +/- 0.15) g and (17.43 +/- 1.85) ng/ml, respectively) were significantly lower than those ((1.27 +/- 0.21) g and (28.25 +/- 3.41) ng/ml, respectively) in TFO treated mice (all P < 0.05). Na(125)I did not significantly affect tumor growth and androgen receptor expression in tumor tissue.</p><p><b>CONCLUSIONS</b>The (125)I-TFO can effectively inhibit androgen receptor expression and tumor growth of human prostate cancer xenografts in vivo. The inhibitory efficacy of (125)I-TFO is more potent than that of TFO, providing a reference for future studies of antigen radiotherapy.</p>

Inhibitory effects of immunotargeting of Chinese cobra cytotoxin and iodine-131 against nasopharyngeal carcinoma cells in vitro / 南方医科大学学报

<p><b>OBJECTIVE</b>To explore a new specific therapy of nasopharyngeal carcinoma (NPC) using an anti-nasopharyngeal carcinoma (NPC) monoclonal antibody BAC5 conjugate with Chinese cobra (CT) and iodine-131(131I).</p><p><b>METHODS</b>BAC5 was labeled with 131I by chloramine-T method, CT was labeled with 125I using iodogen method, and BAC5 and 125I-CT were conjugated by SPDP method. The inhibitory effect of the conjugate on cultured human NPC CNE2 cells was observed using MTT assay.</p><p><b>RESULTS</b>The IC50 of 125I-CT-BAC5 conjugate was 9.17x10(-8) mol/L, and that of 131I-BAC5 was 5.83x10(8) Bq/L, and their combined administration showed obvious inhibitory effect on the NPC cells.</p><p><b>CONCLUSION</b>Both 125I-CT-BAC5 and 131I-BAC5 have obvious inhibition effects against NPC cells, but their combined use shows stronger effects.</p>

Expression, purification, and characterization of the first three immunoglobulin-like domains of human stem cell factor receptor / 中国医学科学院学报

<p><b>OBJECTIVE</b>To express the first three immunoglobulin-like domains of human stem cell factor receptor (c-Kit/Ig1-3) in E. coli and HEK293 ET cells and study their binding activity for stem cell factor (SCF).</p><p><b>METHODS</b>In prokaryotic expression system, a double mutant form of c-Kit /Ig1-3 (c-Kit /Ig1-3(DM) was produced by overlap PCR and cloned into pET16b. The recombinant protein was expressed in E. coli BL21 (DE3) and refolded by dilution. In eukaryotic expression system, the gene of c-Kit/Igl13 with eight histidine segments was cloned into pEAK12 and the recombinant plasmid was transfected into HEK293 ET cells. The fusion protein was harvested from the growth medium and purified on Ni-NTA agarose column. The recombinant protein was tested for the receptor binding activity with his-tag pull-down and enzyme-linked immunosorbent binding assay.</p><p><b>RESULTS</b>In E. coli c-Kit /Ig1-3(DM) as produced as an inclusion body and showed low binding activity for SCF after refolding. Two HEK293 ET cell clones that express high levels of c-Kit/Ig1-3 were produced and each clone secreted 2p micro/ml of recombinant protein, whose relative molecular mass was about 58,000. Eukaryotically expressed c-Kit/Ig1-3 had specific binding activity for SCF, and the dissociation constant (Kd) was 9.39 nmol/L.</p><p><b>CONCLUSION</b>c-Kit/Ig1-3 with high receptor binding activity is successfully produced in HEK293 ET cells.</p>

Expression of human HSF in E. coli and its effects on mobilization of hematopoietic stem cells in rhesus monkeys / 中华血液学杂志

<p><b>OBJECTIVE</b>To study the expression of hHSF in E. coli and its effect on the mobilization of hematopoietic stem/progenitor cells.</p><p><b>METHODS</b>The hHSF gene was obtained by overlapping PCR and cloned into the vector pET30a to yield pET30a-hHSF, which was transformed into E. coli BL21(DE3) and expressed with IPTG induction. Subsequently, rhHSF was purified by gel filtration and cation exchange chromatography and subjected to refolding. Molecular weight of hHSF was measured by MALDI-TOF Mass Spectroscopy. The N terminal amino acid sequence rhHSF was determined by protein sequencing. rhHSF was profiled in rhesus monkey for mobilization of peripheral blood stem cells. Eight rhesus monkeys were equally divided into two groups. The first group was administered single subcutaneous injection of 500 microg/kg hHSF, while the other one was administered 10 microg.kg(-1).d(-1) G-CSF for 4 days followed by a single subcutaneous injection of 500 microg/kg rhHSF.</p><p><b>RESULTS</b>The sequence coding hHSF was confirmed by sequencing and the induced-expression level was about 30% of total cell proteins. The purity of target protein was over 95%. The sequence of N terminal 10 amino acids and the amino acid composition were consistent with the theoretical parameters; molecular weight of rhHSF was 7540. The peripheral CD34(+) cells, CFU-GM yields, and neutrophils peaked at 3 h (16.3-folds increase compared with baseline), 1 h (1.9-folds increase) and 45 min (4.4-folds increase) respectively after the single injection of rhHSF. The addition of rhHSF after the last dose of G-CSF boosted these levels to 25.8-folds, 8.7-folds and 8.3-folds respectively.</p><p><b>CONCLUSION</b>hHSF is highly expressed in E. coli and rapidly mobilizes the hematopoietic stem/progenitor cells and neutrophils in rhesus monkeys. hHSF shows distinct synergistic effect with G-CSF.</p>

Pharmacokinetic study of recombinant human acidic fibroblast growth factor in rabbits by skin external use / 药学学报

<p><b>AIM</b>To investigate the pharmacokinetic characteristics of recombinant human acidic fibroblast growth factor (rhaFGF) after external use in rabbits.</p><p><b>METHODS</b>125I-rhaFGF 180 U.cm-2 was daubed to normal skin and scathed skin in rabbits. The radioactivity and paper chromatography were used to determine the 125I-concentrations and distribution in plasma and organs at different times.</p><p><b>RESULTS</b>The plasma concentration of 125I-rhaFGF increased rapidily, and reach peak plasma level (73.03 pg.mL-1) thirty minutes after administration. Then the concentration of 125I-rhaFGF decreased quickly after thirty minutes, and approached to zero after three hours. Highest radioactivity accumulated in the skin, followed by kidney, lowest in the brain 96 h after administration.</p><p><b>CONCLUSION</b>rhaFGF can not be absorbed from the normal skin, whereas a small amount of rhaFGF can be absorbed through scathed skin. The t1/2 of rhaFGF in plasma was very short. Cumulative effect of rhaFGF was not observed. Absorbed rhaFGF showed high affinity to skin, and can be distributed to skin far from the site of administration.</p>

Experimental study on diagnosing the brachial plexus injury through quickly detecting the ChAT activity / 中华显微外科杂志

Objective To explore a better method to diagnose the brachial plexus injury as pre-or post-ganglionic,which is quick,simple,quantitative,cheap and accurate.Methods Forty-five SD rats were divided randomly ino pre-or post-ganglionic brachial plexus injury models group,and the choline acetyl- transferase(CHAT)activity was detected by using the radioisotope after different days.Results The ChAT activity of two groups both fall day by day:in the pre-agnglionic group,it falls quickly,and reach 1/10 of nor- mal(675?258)cpm;in the post-ganglionic group,it falls slowly,and reach 1/2 of normal even after 90 days (4906?1119)cpm.Conclusion Intra-operative measure of ChAT can be used to differentiate pre-or post- ganglionic brachial plexus injury.