Advances in study of plant type Ⅲ polyketide synthases / 中国中药杂志

Polyketides are a large class of natural products with notable structural diversity and different biological activities. They have essential pharmacological value for human health. In plants, the enzymes responsible for the formation of phenolic metabolites backbone structures are collectively known as type Ⅲ polyketide synthases (PKSs), which are the key enzymes for the polyketides biosynthesis. The PKSs catalyze a series of condensation reactions of two-carbon acetate units with an acyl starter. A brief overview of this group of enzymes, including their reaction mechanisms, function modification, expression regulation, molecular evolution, and recent interesting findings are presented here.

Curative effect of paclitaxel and cisplatin combined chemotherapy on cervical cancer and its relation with tissue micro vascular and lymphatic vessels density

This study was to discuss the curative effect of paclitaxel and cisplatin combined chemotherapy on cerical%miner and its relation with tissue micro vascular and lymphatic vessels density. The combined chemotherapy of paclitaxel 135mg/m2 and cisplatin 25mg/m2 were taken to observe the clinical curative effect. The postoperative paraffin tissue had been collected, had performed the LYVE-1 [lymphatic endothelium specific hyaluronan receptor-1] and CD31 immunohistochemical staining. The complete remission rate of high micro lymphatic vessels density group [was or more 6.0] and high micro vascular density group were obviously higher than in low micro lymphatic vessels density group and low micro vascular density group, the difference was statistically significance [P<0.05]. This study further analyzed the relation of MVD and LVD with clinical pathological parameters. The difference was statistically significant [P<0.01]. The curative effect of paclitaxel and cisplatin combined therapy was promising, positive and was closely related with cervical cancer tissue LVD and MVD. The LVD and MVD could be one of the predictors of early cervical CIN and early cervical cancer development

Study of production of sesquiterpenes of Aquilaria senensis stimulated by Lasiodiplodia theobromae / 中国中药杂志

To investigate the mechanism of agarwood formation in Aquilaria sinensis induced by Lasiodiplodia theobromae, the fermentation liquor of L. theobromae was analyzed qualitatively and quantitatively by gas chromatography-mass spectrometry (GC-MS). JAs were detected in the fermentation liquor. The effect of the fermentation liquor on the abundance of sesquiterpenes in the callus of A. sinensis was analyzed by solid phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS). And the fermentation liquor stimulated alpha-guaiene, alpha-humulene and delta-guaiene biosynthesis in calli. It was inferred that L. theobromae produced JAs, which resulted in a significant increase of sesquiterpenes in A. sinensis.

Analysis of mutations in exon 7 of phenylalanine hydroxylase gene among children with phenylketonuria in Ningxia, China / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To investigate the type and frequency of mutations in exon 7 of phenylalanine hydroxylase (PAH) gene among children with phenylketonuria (PKU) in Ningxia, China and to provide a basis for the genetic diagnosis and prenatal diagnosis of PKU in this region.</p><p><b>METHODS</b>Direct sequencing of PCR product was performed to analyze the sequences of exon 7 and its flanking introns of 146 PAH alleles in 73 children with typical PKU (39 cases of Hui nationality and 34 cases of Han nationality) in Ningxia.</p><p><b>RESULTS</b>Six mutations were detected, including R243Q (14.4%), R241C (6.8%), IVS7+2T→A (2.7%), L255S (0.7%), G247V (0.7%), and G247R (0.7%). The overall frequency of mutations (missense mutation and splice site mutation) in exon 7 was 26.0% (38/146). The detection rate of R241C mutation was significantly higher in children of Hui nationality than in children of Han nationality(10% vs 3%; P<0.05).</p><p><b>CONCLUSIONS</b>In Ningxia, R243Q mutation in exon 7 of PAH gene is most common in children with PKU, followed by R241C. The frequency of R241C mutation in exon 7 of PAH gene varies between children with PKU of Hui and Han nationality.</p>

Cloning and gene expression of acetyl-CoA C-acetyl transferase gene (AsAACT) from Aquilaria sinensis / 中国中药杂志

<p><b>OBJECTIVE</b>This study aimed to clone the acetyl-CoA C-acetyl transferase (AACT) gene from Aquilaria sinensis and analyze the bioinformatics and expression of the gene.</p><p><b>METHOD</b>One unique sequence containing partly AACT gene sequence was discovered in our previous transcriptome dataset of A. sinensis. AACT gene was cloned by RT-PCR and RACE strategy with the template of RNA extracted from A. sinensis stem. The bioinformatic analysis of this gene and its corresponding protein was performed. The AsAACT expression in calli was analyzed with GADPH gene as an internal control gene in wounded condition by qRT-PCR technique.</p><p><b>RESULT</b>One unique sequence of AACT, named as AsAACT, was cloned from A. sinensis. The full length of AsAACT cDNA was containing a 1 236 bp ORF that encoded 411 amino acids. The result of qRT-PCR displayed that the highest expression level was at 4 h. which indicated that it was possibly involved in early-stage response to wound.</p><p><b>CONCLUSION</b>Cloning and analyzing AsAACT gene from A. sinensis provided basic information for study the function and expression regulation of AsAACT in terpenoid biosynthesis.</p>

Expression pattern analysis of terpene synthases of endangered Aquilaria sinensis under different stresses / 中草药

Objective: To analyze the expression of terpene synthases of Aquilaria sinensis, an endangered south medicine, and to predict the influences of the environmental factors and stresses on the synthesis of terpene in A. sinensis. Methods: Two-year old seedlings and calli were treated by different stresses. The gene expression patterns of terpene synthases were analyzed by real-time qPCR. Results: Wounding and cauterizing could induce the transcriptional expression of terpene synthases in the stems, and the effect of cauterizing was more significant. Low temperature inhibited the transcription of terpene synthases. In calli, methyl jasmonate (MeJA) treatment had the most effective induction. Conclusion: Both wounding and cauterizing could induce the synthesis of terpenes in stems, while the cauterizing treatment might have better effect. Low temperature has negative influence on agarwood formation. For calli, different treatments could induce the terpene synthesis, while MeJA has the best efficacy.

The mechanical wound transcriptome of three-year-old Aquilaria sinensis / 药学学报

Chinese agarwood is formed in the aromatic resinous wood formed in Aquilaria sinensis (Lour.) Gilg (botanical family: Thymelaeaceae). Only when suffering stress of wound, etc, can A. sinensis produce sesquiterpenes etc. compounds of agarwood around wounds. However, little is known about how wound induced the biosynthesis pathway of sesquiterpenes. To reveal the molecular mechanism of wound-induced agarwood formation, RNA sequencing (RNA-seq) technology was used to investigate the profile of gene expression in A. sinensis treated by mechanical wounding and elucidate its functional gene. A total of 40,295 ESTs with an average read length of 305 bp were generated and 22 095 unigenes were formed by initial gene splicing. 61.6% of these unigenes (13 611) were annotated using BLAST searches against the SwissProt, KEGG, Nr and Nt databases. Twenty-six unigenes (encoding 7 enzymes) were found to be involved in sesquiterpene of agarwood biosynthesis by bioinformatic tools of Gene Ontology and KEGG. Novel genes that are potentially involved in sesquiterpenes biosynthesis were identified in A. sinensis, providing data for further sesquiterpenes biosynthesis pathway by molecular methods and the EST data establish a foundation for future studies in the molecular mechanisms of wound-induce agarwood formation in A. sinensis.

Purification and Characterization of Glucagon-Like Peptide-1 and Human Serum Albumin Fusion Protein Expressed in Pichia pastoris / 微生物学通报

A fusion protein of glucagons-like peptide-1 and human serum albumin (GLP-1/HSA) was expressed and secreted into the fermentation broth with recombinant Pichia pastoris. The productivity of expressed GLP-1/HSA could reach 63.6mg/L in 10L fermentor. After concentrated with hollow-fiber ultrafiltration membrane, GLP-1/HSA was purified from fermentation broth by hydrophobic chromatography, negative ion exchange chromatography and gel filtration chromatography in turn. The HPLC analysis showed that the purified GLP-1/HSA had an overall purity of 95.8%. Furthermore, the analysis of in vivo activity indicated that GLP-1/HSA had the bioactivity of native GLP-1, and could significantly reduce blood glucose level 4h after intraperitoneal administration. It was concluded that a great deal of GLP-1/HSA with higher purity could be harvested by Pichia pastoris expression system and the established purification methods. Preliminary studies show a new potential for developing the long-acting GLP-1 analogs for clinical applications.