Specific DNA barcodes screening, germplasm resource identification, and genetic diversity analysis of Platycodon grandiflorum / 药学学报

Platycodonis Radix is the dry root of Platycodon grandiflorum of Campanulaceae, which has a variety of pharmacological effects and is a commonly used bulk Chinese medicine. In this study, the chloroplast genome sequences of six P. grandiflorum from different producing areas has been sequenced with Illumina HiSeq X Ten platform. The specific DNA barcodes were screened, and the germplasm resources and genetic diversity were analyzed according to the specific barcodes. The total length of the chloroplast genome of 6 P. grandiflorum samples was 172 260-172 275 bp, and all chloroplast genomes showed a typical circular tetrad structure and encoded 141 genes. The comparative genomics analysis and results of amplification efficiency demonstrated that trnG-UCC and ndhG_ndhF were the potential specific DNA barcodes for identification the germplasm resources of P. grandiflorum. A total of 305 P. grandiflorum samples were collected from 15 production areas in 9 provinces, for which the fragments of trnG-UCC and ndhG_ndhF were amplificated and the sequences were analyzed. The results showed that trnG-UCC and ndhG_ndhF have 5 and 11 mutation sites, respectively, and 5 and 7 haplotypes were identified, respectively. The combined analysis of the two sequences formed 13 haplotypes (named Hap1-Hap13), and Hap4 is the main genotype, followed by Hap1. The unique haplotypes possessed by the three producing areas can be used as DNA molecular tags in this area to distinguish from the germplasm resources of P. grandiflorum from other areas. The haplotype diversity, nucleotide diversity and genetic distance were 0.94, 4.79×10-3 and 0.000 0-0.020 3, respectively, suggesting that the genetic diversity was abundant and intraspecific kinship was relatively close. This study laid a foundation for the identification of P. grandiflorum, the protection and utilization of germplasm resources, and molecular breeding.

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.

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.

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.

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.

Expression of DR5 in endotoxin-induced uveitis of rat / 眼科新进展

Objective To observe the expression of DR5 in the ocular tissues of uveitis rats induced by endotoxin,and study the relationship between the apoptosis of inflammatory cells and expression of TRAIL / DR5.Methods SD rats were randomly divided into 3 groups:Blank control group,normal saline injection group and endotoxin injection group.The endotoxin injection group was injected with lipopolysaccharide into the rat posterior foot pad to make endotoxin-induced uveitis animal model.There were no operations in the blank control group,and the subgroups were divided into 6 hours,12 hours,24 hours and 48 hours groups according to the time of injection.The ultrastructural changes of inflammatory cells and endothelial cells in iris capillaries were observed by transmission electron microscopy (TEM).The expression of DtR5 protein on inflammatory cells at different time after endotoxin induction was detected by SABC method.Results TEM showed that the microvilli of the capillary endothelial cells in the iris tissue of the blank control group and saline injection group had more obvious vesicles with no obvious abnormal structure and shape.The number of swallowed vesicles in the capillary endothelial cells injected with endotoxin was decreased at 6 hours group,and the number of vesicles in the infiltrating neutrophils and lymphocytes decreased.Neutrophils and lymphocytes appear chromatin condensation,vacuolar changes in the expression of apoptosis.Immunohistochemistry showed that the DR5 protein was negative in the iridocular epithelium of the blank control group and saline injection group.In the endotoxin injection group,the DR5 protein was weakly colored in the iris pigment epithelium and appeared on the inflammatory cells.The number of staining and the intensity of coloring in the 24 hours group were significantly higher than those in the 6 hours group,and the color density was 0.085 9 ± 0.019 6,there were statistical differences compared with 6 hours group,12 hours group and 48 hours group (all P ＜ 0.05).Conclusion TRAIL and its receptor DR5 may be involved in the apoptosis of inflammatory cells in endotoxin-induced uveitis.

Inhibitory effect of apigenin on human Tenon capsule fibroblasts / 中华实验眼科杂志

Background Proliferation of the human Tenon capsule fibroblasts(HTFs) is a main cause of failure of filtering surgery.To search the drug of inhibiting the growth of the HTFs is essential for the improvement of successful rate of filtering surgery.Objective The aim of this study was to investigate the inhibitory effect of apigenin on HTFs and its mechanism.Methods Human Tenon capsular tissue was obtained during the strabismus correction surgery.HTFs was primarily cultured using explant method and identified using vimentin by immunochemistry.The 3-5 generation of cells were incubated to 96-well plate.Apigenin of 0,20,40,80,160 μmol/L was added into the medium,respectively,for 24,48,72 hours,and the proliferation of HTFs was detected by sulfonyl chloride (SRB) at the wavelength of 560 nm (A560).Bromodeoxyuridine (BrdU) of 10 μg/L was added to culture the cells for 48 hours to calculate the labeling rate of BrdU.The morphology of the cells was observed using Hoechst 33258 staining,and apoptosis and cells cycle were evaluated by flow cytometry.Results Cultured cells grew well with the positive response for vimentin,showing the green fluorescence in cytoplasm.SRB assay showed that the A560 value was gradually declined with the increase of the dosage of apigenin and prolong of time (Fgroup =480.306,P =0.000 ; Ftime =555.144,P =0.000).The labeling rate after 0,40,80 μmol/L apigenin acted for 48 hours was (87.860 ±0.632)％,(61.520±4.306)％ and (23.480±4.472)％,showing a significant difference among the three groups (F =299.347,P =0.000).The labeling rate of HTFs for BrdU was significantly decreased in the 40 and 80 μmol/L apigenin groups compared with the 0 μmol/L apigenin group (P＜0.05).Hoechse 33258 staining found that the number of the HTFs was gradually decreased and the cell number of karyopyknosis and nuclear deformation was increased with the increase of apigenin dosage.Percentage of cells in G0/G1 phase were raised and that in S and G2/M phase were declined in the higher dosage apigenin group,with a significant difference among the different groups (FG0/G1 =58.621,P=0.000;Fs =32.357,P=0.001 ;FG2/M =83.998,P=0.000).In the 72nd hour after acted by 0,40,80,160 μmol/L apigenin,the apoptosis rate of HTFs was (4.77±0.21) ％,(13.24±1.35)％,(18.33±1.86) ％,(31.58 ± 2.77) ％,respectively,with a statistically significant difference among the four groups (F =204.791,P＜0.05).Conclusions Apigenin restrains the growth of HTFs by evoking G0/G1 cell cycle arrest and inducing apoptosis in a dosage-and time-dependent manner.

Effects of insulin on proteolysis of cultured rabbit skeletal muscular myotubes in vitro / 中华烧伤杂志

<p><b>OBJECTIVE</b>To study the effects of insulin on the proteolysis of cultured rabbit skeletal muscular myotubes in vitro, and their possible mechanisms.</p><p><b>METHODS</b>Muscles of lower limbs of juvenile rabbits were isolated for tissue-block culture. After passage, myoblasts were formed and fused into myotubes. Then the protein in myotubes was radiolabelled with L-[ 3,5-3H] tyrosine. The myotubes were cultured in DMEM medium containing 100 nmol/L insulin (n = 24, group B) , 100 nmol/L dexamethasone (n = 24, group C) , 100 nmol/L insulin and 100 nmol/L dexamethasone (n = 24, group D) , no insulin or dexamethasone (n =24, group A), respectively. Twenty-four hours after culture, the L-[3,5-3H] tyrosine content in culture medium and cells were determined, and the degradation rates of protein were calculated. The mRNA expressions of ubiquitin and protease C2 subunit were determined by Northern blot.</p><p><b>RESULTS</b>The degradation rates of myotube protein in group A(0. 38+/-0.04) was obviously lower than that in group C (0.50+/-0.03, P <0.01), but it was obviously higher than that in group B(0. 35+/-0.03, P <0.05). Though the degradation rates of myotube protein in group D (0.41+/-0. 03) was evidently lower than that in group C ( P < 0.01) , it was still higher than that in group A( P < 0.05 ). The mRNA expressions of ubiquitin and protease C2 subunit in group A ( the scale: 2. 4 kb ubiquitin was 0. 82+/-0. 15, 1. 2 kb ubiquitin was 0. 60+/-0. 10, C2 subunit was 0. 75+/-0. 16) was obviously lower than that in group C ( the scale: 2.4 kb ubiquitin was 2. 15+/-0. 23, 1.2 kb ubiquitin was 1.50+/-0. 14,C2 subunit was 1.50+/-0. 13 , P <0. 01) , but it in group D was lower than that in group C (the scale: 2. 4 kb ubiquitin was 1. 25+/-0. 17, 1. 2 kb ubiquitin was 0. 85+/-0. 09, C2 subunit was 0. 90+/-0. 15, P <0. 01) , and it was similar to that in group B (the scale: 2.4 kb ubiquitin was 0. 85+/-0.07, 1.2 kb ubiquitin was 0. 65+/- 0. 12, C2 subunit was 0. 76 +/-0. 09, P > 0. 05).</p><p><b>CONCLUSION</b>The effects of insulin on the activity of ubiquitin-proteasome pathway and the proteolytic rate in normal myotubes were relatively weak. However, insulin can significantly inhibit the effects of dexamethasone on the gene expressions of ubiquitin system and the proteolytic rate in myotubes, but the mechanism needs further research.</p>