Specific DNA barcodes, germplasm resources, and genetic diversity of Eleutherococcus senticosus / 中国中药杂志

Eleutherococcus senticosus is one of the Dao-di herbs in northeast China. In this study, the chloroplast genomes of three E. senticosus samples from different genuine producing areas were sequenced and then used for the screening of specific DNA barcodes. The germplasm resources and genetic diversity of E. senticosus were analyzed basing on the specific DNA barcodes. The chloroplast genomes of E. senticosus from different genuine producing areas showed the total length of 156 779-156 781 bp and a typical tetrad structure. Each of the chloroplast genomes carried 132 genes, including 87 protein-coding genes, 37 tRNAs, and 8 rRNAs. The chloroplast genomes were relatively conserved. Sequence analysis of the three chloroplast genomes indicated that atpI, ndhA, ycf1, atpB-rbcL, ndhF-rpl32, petA-psbJ, psbM-psbD, and rps16-psbK can be used as specific DNA barcodes of E. senticosus. In this study, we selected atpI and atpB-rbcL which were 700-800 bp and easy to be amplified for the identification of 184 E. senticosus samples from 13 genuine producing areas. The results demonstrated that 9 and 10 genotypes were identified based on atpI and atpB-rbcL sequences, respectively. Furthermore, the two barcodes identified 23 genotypes which were named H1-H23. The haplotype with the highest proportion and widest distribution was H10, followed by H2. The haplotype diversity and nucleotide diversity were 0.94 and 1.82×10~(-3), respectively, suggesting the high genetic diversity of E. senticosus. The results of the median-joining network analysis showed that the 23 genotypes could be classified into 4 categories. H2 was the oldest haplotype, and it served as the center of the network characterized by starlike radiation, which suggested that population expansion of E. senticosus occurred in the genuine producing areas. This study lays a foundation for the research on the genetic quality and chloroplast genetic engineering of E. senticosus and further research on the genetic mechanism of its population, providing new ideas for studying the genetic evolution of E. senticosus.

Screening of specific DNA barcode, identification of germplasm resources, and analysis of genetic diversity of Atractylodes chinenesis / 药学学报

italic>Atractylodes chinensis has important medicinal and economic values. In this study, the chloroplast genome sequences of four A. chinensis samples from different producing areas were sequenced using the Illumina platform. The specific DNA barcodes were screened and the germplasm resources of A. chinensis samples from different producing areas and the genetic diversity of the population were analyzed basing on the specific barcodes. The whole chloroplast genomes of the four A. chinensis samples had a typical cyclic tetrad structure, with 112 genes annotated. The comparative genomics results indicated that ccsA and trnC-GCA_petN were potential specific DNA barcodes for intraspecific identification of A. chinensis. Polymerase chain reaction (PCR) analysis of ccsA and trnC-GCA_petN was performed on 256 samples from 14 areas in 9 provinces, and the amplification efficiency was 100%. Sequence analysis showed that ccsA and trnC-GCA_petN had 11 and 22 variant positions, which could identify 16 and 22 haplotypes, respectively. The combined sequence analysis identified 39 haplotypes, named Hap1-Hap39, of which the most abundant and widely distributed genotype was Hap9. Haplotype diversity (Hd) = 0.896 and nucleotide diversity (Pi) = 0.002 22 indicated high genetic diversity at the species level in A. chinensis. The genetic distances of the haplotypes were 0.000 00-0.004 88, indicating that there were small genetic differences among the haplotypes. The results of phylogenetic tree analysis showed that 39 haplotypes had very close genetic relationship, and formed two obvious branches with other groups of the same genus except Atractylodes macrocephala. This study plays an important role in the identification of the origin of A. chinensis and the protection and breeding of germplasm resources.

Levofloxacin combined with cellulase can eradicate bacille Calmette-Guerin biofilm infection / 南方医科大学学报

OBJECTIVE@#To investigate the inhibitory effects of levofloxacin (LEV) combined with cellulase against bacille CalmetteGuerin (BCG) biofilms in vitro.@*METHODS@#The mature growth cycle of BCG biofilms was determined using the XTT method and crystal violet staining. BCG planktonic bacteria and BCG biofilms were treated with different concentrations of LEV and cellulose alone or jointly, and the changes in biofilm biomass were quantified with crystal violet staining. The mature BCG biofilm was then treated with cellulase alone for 24 h, and after staining with SYTO 9 and Calcofluor White Stain, the number of viable bacteria and the change in cellulose content in the biofilm were observed with confocal laser scanning microscopy. The structural changes of the treated biofilm were observed under scanning electron microscopy.@*RESULTS@#The MIC, MBC and MBEC values of LEV determined by broth microdilution method were 4 μg/mL, 8 μg/mL and 1024 μg/mL, respectively. The combined treatment with 1/4×MIC LEV and 2.56, 5.12 or 10.24 U/mL cellulase resulted in a significant reduction in biofilm biomass (P < 0.001). Cellulase treatments at the concentrations of 10.24, 5.12 and 2.56 U/mL all produced significant dispersion effects on mature BCG biofilms (P < 0.001).@*CONCLUSION@#LEV combined with cellulose can effectively eradicate BCG biofilm infections, suggesting the potential of glycoside hydrolase therapy for improving the efficacy of antibiotics against biofilmassociated infections caused by Mycobacterium tuberculosis.

Semi-rational design improves the catalytic activity of phenylalanine ammonia lyase from Anabaena variabilis / 药学学报

Phenylalanine ammonia lyase (PAL) can catalyze L-phenylalanine to produce trans-cinnamic acid, which is widely used in the fields of pharmacy, food and agriculture. In particular, phenylalanine ammonia lyase from Anabaena variabilis (AvPAL) is the only protein drug for the treatment of phenylketonuria. However, the poor activity and low stability limit the application in industry of AvPAL. In this study, the key amino acids of substrate-binding cavity in AvPAL were identified by screening the single site saturation mutagenesis library. Subsequently, the impact of replacing M222 with the additional 19 amino acids on activity was also evaluated by site-directed mutagenesis. It was found that the kcat values of mutants M222L and M222V were 90% and 60% higher than that of AvPAL, and the kcat/Km was 1.4 and 1.5 times as that of AvPAL. Molecular docking results revealed that the higher activity of M222L and M222V may be due to the increase of hydrophobicity favorable for the substrate-binding cavity. This study is important for elucidating the structure-function relationship of AvPAL.

Cloning and subcellular location of the PnMYB1R1 gene from Panax notoginseng and expression analysis with different stresses / 药学学报

MYB transcription factors, one of the largest transcription factor families in plants, play an important role in signal transduction, plant growth and plant resistance. In this study a full-length cDNA of the PnMYB1R1 gene was cloned from Panax notoginseng. Sequence analysis, prokaryotic expression and purification, subcellular location, transcriptional activity analysis, tissue-specific analysis and expression analysis under different abiotic stresses was performed. The open reading frame (ORF) of PnMYB1R gene was 738 bp, encoding a protein of 245 amino acids with a predicted molecular mass (MW) of 27.0 kD. The sequence analysis and polygenetic analysis indicated that the PnMYB1R1 protein contains a conserved R3 domain, belonging to TRF-like protein in 1R-MYB-type transcription factors. The recombinant PnMYB1R1 protein was expressed in Escherichia coli BL21(DE3) cells using the prokaryotic expression vector pET28a-PnMYB1R1 and was purified. Subcellular localization analysis showed that PnMYB1R1 was localized in the nucleus. Transcriptional activity analysis indicated that the PnMYB1R1 transcription factor has transcriptional activation activity. Expression analysis indicated that PnMYB1R1 was primarily expressed in roots, followed by stems and leaves, and then rootlets. The expression level of PnMYB1R1 in root, stems, leaves and rootlets was influenced by salt, low temperature and drought treatment, while the abundance of PnMYB1R1 was significantly induced by salt stress in these tissues. These results provide valuable insights into the role of 1R-MYB transcription factors in plant defense.

Molecular identification and quality analysis of Rhei Rhizoma based on chloroplast matK gene and UPLC / 药学学报

Rhei Rhizoma is commonly used as a traditional Chinese medicine with multiple botanical origins. Different botanical sources may have different pharmacological activities. The germplasm resources of commercial Rhei Rhizoma were determined based on the chloroplast gene matK, and the anthraquinone and free anthraquinone content was determined by UPLC to analyze quality of commercial Rhei Rhizoma. Eighty-nine commercial Rhei Rhizoma samples were collected from 40 cities in 27 provinces. DNA was extracted and the matK gene was amplified by PCR. Results indicated that the collected samples were from the same botanical origin, Rheum palmatum, and 8 genotypes were identified, including Rp1, Rp2, Rp3, Rp4, Rp5, Rp6, Rp10 and Rp12. Rp4 and Rp6, cultivated in Gansu, Sichuan and Yunnan provinces were the main circulating genotypes, representing 40.45% and 37.08% of the total samples, respectively. Phylogenetic tree analysis showed that the eight genotypes were mainly divided into two branches, of which the main genotypes Rp4 and Rp6 were in one branch. Genetic distance analysis indicated that the genetic separation of the eight genotypes was between 0.001 and 0.010. UPLC analysis indicated that 93.26% of the samples met the Pharmacopoeia standards. There were significant differences in the content of total anthraquinone and free anthraquinone among the samples, in which the difference in free anthraquinone was 1.01% and the difference in total anthraquinone content was 3.79%, indicating that the quality of commercial Rhei Rhizoma samples varies considerably. There was no significant difference in the content of total anthraquinone and free anthraquinone in commercial Rhei Rhizoma among different collection provinces and genotypes. This study will help guide the circulation of Rhei Rhizoma in the market and provides valuable insights for molecular identification and quality analysis of other traditional Chinese medicines.

Identification and quality evaluation of germplasm resources of commercial Scutellaria baicalensis based on DNA barcode and HPLC / 中国中药杂志

Scutellaria baicalensis is a commonly used Chinese medicinal herb. In this study, we identified the germplasm resources of commercial S. baicalensis samples based on trnH-psbA, petA-psbJ, and ycf4-cemA sequences according to the available chloroplast genome sequencing results, and measured the content of baicalin by HPLC. Through the above means we determined the best DNA barcode that can be used to detect the germplasm resources and evaluate the quality of commercial S. baicalensis samples. A total of 104 samples were collected from 24 provinces, from which DNA was extracted for PCR amplification. The amplification efficiencies of trnH-psbA, petA-psbJ, and ycf4-cemA sequences were 100%, 59.62%, and 25.96%, respectively. The results of sequence analysis showed that 5, 4, and 2 haplotypes were identified based on trnH-psbA, petA-psbJ, and ycf4-cemA sequences, respectively. However, the sequences of haplotypes in commercial samples were different from that of the wild type, and the joint analysis of three fragments of S. baicalensis only identified 6 haplotypes. Furthermore, the phylogenetic analysis and genetic distance analysis indicated that trnH-psbA could be used to identify S. baicalensis from adulterants. The above analysis showed that trnH-psbA was the best fragment for identifying the germplasm resources of commercial S. baicalensis samples. We then analyzed the haplotypes(THap1-THap5) of commercial S. baicalensis samples based on trnH-psbA and found that THap2 was the main circulating haplotype of the commercial samples, accounting for 86.55% of the total samples, which indicated the scarce germplasm resources of commercial S. baicalensis samples. The content of baicalin in all the collected commercial S. baicalensis samples exceeded the standard in Chinese Pharmacopoeia and had significant differences(maximum of 12.21%) among samples, suggesting that the quality of commercial S. baicalensis samples varied considerably. However, there was no significant difference in baicalin content between different provinces or between different haplotypes. This study facilitates the establishment of the standard identification system for S. baicalensis, and can guide the commercial circulation and reasonable medication of S. baicalensis.

Follistatin-Like 1 Promotes Bleomycin-Induced Pulmonary Fibrosis through the Transforming Growth Factor Beta 1/Mitogen-Activated Protein Kinase Signaling Pathway / 中华医学杂志(英文版)

Background@#Follistatin-like 1 (FSTL1) is a novel profibrogenic factor that induces pulmonary fibrosis (PF) through the transforming growth factor-beta 1 (TGF-β1)/Smad signaling. Little is known about its effects on PF through the non-Smad signaling, like the mitogen-activated protein kinase (MAPK) pathway. Therefore, this study aimed to investigate the role of FSTL1 in PF through the MAPK signaling pathway and its mechanisms in lung fibrogenesis.@*Methods@#PF was induced in Fstl1and wild-type (WT) C57BL/6 mice with bleomycin. After 14 days, the mice were sacrificed, and lung tissues were stained with hematoxylin and eosin; the hydroxyproline content was measured to confirm PF. The mRNA and protein level of FSTL1 and the change of MAPK phosphorylation were measured by quantitative polymerase chain reaction and Western blotting. The effect of Fstl1 deficiency on fibroblasts differentiation was measured by Western blotting and cell immunofluorescence. MAPK signaling activation was measured by Western blotting in Fstl1 and WT fibroblasts treated with recombinant human FSTL1 protein. We pretreated mouse lung fibroblast cells with inhibitors of the extracellular signal-regulated kinase (ERK), p38, and Jun N-terminal kinase (JNK) signaling and analyzed their differentiation, proliferation, migration, and invasion by Western blotting, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide analysis, and transwell assays. The Student's t-test was used to compare the differences between two groups.@*Results@#Fstl1 deficiency attenuated phosphorylation of the ERK, p38, and JNK signaling in bleomycin-induced fibrotic lung tissue 14 days after injury (0.67 ± 0.05 vs. 1.22 ± 0.03, t = 14.92, P = 0.0001; 0.41 ± 0.01 vs. 1.15 ± 0.07; t = 11.19; P = 0.0004; and 0.41 ± 0.01 vs. 1.07 ± 0.07, t = 8.92, P = 0.0009; respectively), compared with WT lungs at the same time and in primary lung fibroblasts (0.82 ± 0.01 vs. 1.01 ± 0.04, t = 4.06, P = 0.0150; 1.04 ± 0.03 vs. 1.24 ± 0.03, t = 4.44, P = 0.0100; and 0.76 ± 0.05 vs. 0.99 ± 0.05, t = 4.48, P = 0.0100; respectively), compared with TGF-β1-stimulated WT group. Recombinant human FSTL1 protein in lung fibroblasts enhanced TGF-β1-mediated phosphorylation of the ERK (1.19 ± 0.08 vs. 0.55 ± 0.04, t = 6.99, P = 0.0020), p38 (1.18 ± 0.04 vs. 0.66 ± 0.03, t = 11.20, P = 0.0020), and JNK (1.11 ± 0.01 vs. 0.84 ± 0.04, t = 6.53, P = 0.0030), compared with the TGF-β1-stimulated WT group. Fstl1-deficient fibroblasts showed reduced alpha-smooth muscle actin (α-SMA) expression (0.70 ± 0.06 vs. 1.28 ± 0.11, t = 4.65, P = 0.0035, compared with the untreated WT group; 1.40 ± 0.05 vs. 1.76 ± 0.02, t = 6.31, P = 0.0007; compared with the TGF-β1-treated WT group). Compared with the corresponding condition in the control group, the TGF-β1/FSTL1-mediated α-SMA expression was significantly suppressed by pretreatment with an inhibitor of p38 (0.73 ± 0.01 vs. 1.13 ± 0.10, t = 3.92, P = 0.0078) and JNK (0.78 ± 0.03 vs. 1.08 ± 0.06, t = 4.40, P = 0.0046) signaling. The proliferation of mouse lung fibroblast cells (MLgs) significantly decreased after treatment of an inhibitor of p38 (0.30 ± 0.01 vs. 0.46 ± 0.03, t = 4.64, P = 0.0009), JNK (0.30 ± 0.01 vs. 0.49 ± 0.01, t = 12.84, P = 0.0001), and Smad2/3 (0.18 ± 0.02 vs. 0.46 ± 0.02, t = 12.69, P = 0.0001) signaling compared with the dimethylsulfoxide group. The migration and invasion cells of MLgs significantly decreased in medium pretreated with an inhibitor of p38 (70.17 ± 3.28 vs. 116.30 ± 7.11, t = 5.89, P = 0.0042 for the migratory cells; 19.87 ± 0.84 vs. 32.70 ± 0.95, t = 10.14, P = 0.0005 for the invasive cells), JNK (72.30 ± 3.85 vs. 116.30 ± 7.11, t = 5.44, P = 0.0056 for the migratory cells; 18.03 ± 0.94 vs. 32.70 ± 0.95, t = 11.00, P = 0.0004 for the invasive cells), and Smad2/3 (64.76 ± 1.41 vs. 116.30 ± 7.11, t = 7.11, P = 0.0021 for the migratory cells; 18.03 ± 0.94 vs. 32.70 ± 0.95, t = 13.29, P = 0.0002 for the invasive cells) signaling compared with the corresponding condition in the dimethylsulfoxide group.@*Conclusion@#FSTL1 affects lung fibroblast differentiation, proliferation, migration, and invasion through p38 and JNK signaling, and in this way, it might influence the development of PF.

Arrhythmia triggered by stretching rabbit left ventricles and the block effect of streptomysin / 中国应用生理学杂志

<p><b>AIM</b>To observe the effect of stretching left ventricles in the end of action potential on rabbit cardiac activity, and to investigate its possible mechanisms.</p><p><b>METHODS</b>Stretch (120 mmHg, 50 ms) was applied in the end of action potential by the pressure-clamp technique to observe if there would be any changes in rabbit cardiac activity and streptomycin (500 micromol/L) was used to identify the mechanism.</p><p><b>RESULTS</b>Stretch in the end of action potential caused arrhythmia (P < 0.05) and streptomycin blocked the above effect (P < 0.05).</p><p><b>CONCLUSION</b>Streptomycin could block the effect of stretching left ventricles in the end of action potential on rabbit cardiac activity, which indicates that stretch-activated ion channels involve it.</p>

A ventricular pressure-clamping system for the study of mechano-electrical feedback / 生理学报

It is necessary to control the mechanical stimuli precisely in the studies of cardiac mechano-electrical feedback (MEF). In the present study a ventricular pressure-clamping system has been developed, which can be applied to isolated-perfused rabbit hearts. Controlled by a computer, this system not only can make the left ventricle follow a command defining the same pressure wave as that during a beating cycle under physiological condition, but also deliver mechanical stimuli with a proper waveform to the ventricle at a particular time phase. This system integrates multiple functions, including perfusing, pacing, recording of electrocardiogram and monophasic action potentials, and clamping and measuring of ventricular pressures in isolated-perfused hearts. Thus, it is a distinct system for investigating the phenomena and mechanisms of cardiac MEF at organ level.