Traditional herbal medicines, Panax ginseng, Panax quinquefolium and Panax notoginseng, attract our attention for their extensive and powerful pharmacological activities. Ginsenosides are the main active constituents of these medicinal herbs. The related glycosyltransferases involved in ginsenoside biosynthesis are the key enzymes which catalyze the last important step. Modification of ginsenoside aglycones by glycosyltransferases produces the complexity and diversity of ginsenosides, which have more extensive pharmacological activity. At present, ginsenoside aglycones and compound K have been obtained by synthetic biology. As the last step of ginsenoside biosynthesis, glycosylation of ginsenoside aglycones has been studied intensively in recent years. This review summarizes the basic strategies and research advances in studies on glycosyltransferases involved in ginsenoside biosynthesis, which is expected to lay the theoretical foundation for the in-depth research of biosynthetic pathway of ginsenosides and their production by synthetic biology.
Biosynthetic Pathways ; Ginsenosides ; biosynthesis ; Glycosyltransferases ; metabolism ; Panax ; chemistry ; Plants, Medicinal ; chemistry ; Synthetic Biology

Pichia pastoris is one of the most important systems used in the field of molecular biology for the expression of recombinant proteins. The system has advantages of high expression, high stability, high secretion, easy high-density fermentation and low cost. Many factors affect the expression of recombinant protein, such as gene copy number, codon usage preference, type of promoter, molecular chaperones, glycosylation, signal peptide and fermentation process. In this review, research advances of the above aspects are summarized, which lay a foundation for improving the expression of recombinant proteins in P. pastoris.
Fermentation ; Gene Dosage ; Glycosylation ; Molecular Chaperones ; Pichia ; metabolism ; Promoter Regions, Genetic ; Protein Sorting Signals ; Recombinant Proteins ; biosynthesis

Lanosterol synthase is encoded by the erg7 gene and catalyzes the cyclization of 2, 3-oxidosqualene, which is a rate-limiting step of the inherent mevalonate (MVA)/ergosterol metabolic pathway in Saccharomyces cerevisiae. The intermediate 2, 3-oxidosqualene is also the precursor of triterpenoids. Therefore, the cyclization of 2, 3-oxidosqualene is the key branch point of ergosterol and triterpenoids biosynthesis. Down-regulation of 2, 3-oxidosqualene metabolic flux to ergosterol in S. cerevisiae may redirect the metabolic flux toward the triterpenoid synthetic pathway reconstructed by the synthetic biology approach. To construct erg7 knockout cassette harboring the loxP-Marker-loxP element, long primers were designed, which were homologous to the sequences of both erg7 ORF and plasmid pUG66. The cassette was transformed into diploid wild strain INVSc1 by LiAc/SS Carrier DNA/PEG method and then erg7 gene haploid deficient mutant was obtained by homologous recombination. The results of semiquantitative PCR and real-time quantitative PCR revealed that erg7 expression level in erg7 gene haploid deficient mutant is one time lower than that in wild strain. The results of TLC and HPLC showed that the ergosterol content in deficient mutant decreased to 42% of that in wild strain.
Chromatography, High Pressure Liquid ; DNA Primers ; Down-Regulation ; Ergosterol ; metabolism ; Haploidy ; Intramolecular Transferases ; genetics ; Polymerase Chain Reaction ; Saccharomyces cerevisiae ; genetics ; Squalene ; analogs & derivatives ; metabolism

AIM: To identify an unknown peak in Guanxinning Injection(Radix et Rhizome Salviae Miltiorrhizae,Rhizoma Chuanxiong) chromatographic fingerprint. METHODS: The elution(44-46 min) separated and collected by HPLC was analyzed by GC-MS and HPLC-PDA-MS-MS. RESULTS: The unknown peak was corresponding to senkyunolidel I. CONCLUSION: It is quick method to identify the reported chemical in herbal medicine based on a small quantity of sample by GC-MS and HPLC-PDA-MS-MS.

AIM: To seek a small interfering RNA ( siRNA ) sequence targeting rat inhibitor of nuclear factor kappa Bα ( IκBα) that can specifically and effectively suppress IκBα mRNA expression of rat ciliary muscles in vivo.METHODS:Three IκBα specific double stranded siRNAs were designed and synthesized. They were transfected into rat A7r5 cells which express IκBα gene. Flow cytometry was used to assess transfected efficiency. The mRNA and protein levels of IκBα were examined by Real Time quantitative polymerase chain reaction ( Real Time-PCR ) and western blot to screen a candidate valid sequence with the highest inhibitory rate. The Cy3 labeled non-specific control siRNA or the candidate valid siRNA was then injected into rat anterior chamber. Distribution of Cy3- siRNA in rat ciliary muscles was viewed by fluorescence microscopy, and the inhibitory effect in vivo of the valid siRNA was identified via Real Time-PCR and immunofluorescence. RESULTS: The suppression effect of the siRNA targeting the CTACGATGACTGTGTGTTT of IκBα gene was most obvious by vitro screening. By anterior chamber injection, this valid siRNA could reach rat ciliary muscles and effectively suppress IκBα gene expression with the highest inhibitory rate of 59. 0% on mRNA level at 24h after RNAi, and 52. 3% on protein level at 72h after RNAi (P<0. 01).CONCLUSION: It proves that the siRNA targeting the CTACGATGACTGTGTGTTT of IκBα gene is the valid sequence to suppress rat IκBα expression of ciliary muscles by RNAi in vivo.

Objective To investigate spliceosome of suppresser of fused(SUFU),a major member of hedgehog signaling pathway in human pancreatic cancer.Methods SUFU fragment was amplified by using reverse transcription and 3' RACE.After sequencing,a new exon was discovered,and then nSUFU was amplified by RT-PCR.nSUFU and SUFU were transfected into SW1990 by liposomes,and then the expressions of SUFU protein encoded by new spliceosome in SW1990 cells and pancreatic cancer tissues were detected by Western blot.Results PCR products by 3'RACE were of 600 bp,after sequencing and comparison with Blast data of NCBI,it was detected that a new exon was inserted between SUFU mRNA isoforml (NM_016169.3) exon 10 and exon 11.After verification with SW1990,it was noted the entire new spliceosome containing new exon was of 1400 bp.SW1990 with nSUFU transfection strongly expressed nSUFU protein,and pancreatic cancer tissues expressed both SUFU and nSUFU protein.Conclusions A new spliceosome of SUFU,which can encode SUFU protein,is present in pancreatic cancer tissue and cell.

To observe the clinical results of innercapsular phacoemulsification with primary intraocular lens ( lOL ) implantation in the treatment of lens dislocation.METHODS: A total of 23 cases ( 23 eyes ) of lens dislocation ( lla and llb ) were underwent innercapsular phacoemulsification combined with primary lOL implantation. lOL implantation were underwent during operation, the complications of intraoperative and postoperative, postoperative vision, intraocular pressure ( lOP ) , corneal endothelial cell, lOL location were analyzed.RESULTS: The operations were successfully completed for all patients in accordance with the pre - surgery program; lens nucleus or its fragments did not crash into the vitreous cavity; 20 cases of corneal edema and 17 cases of lOP presented at the first day after surgery, the deviation or displacement of lOL and serious complications such as retinal detachment were not appeared. At the first week postoperation, the average lOP was 15. 81 ± 2. 10mmHg, with statistically significant differences when compared with the preoperative ( P<0. 01 ) , the visual acuity in all eases increased, with statistically significant differences when compared with the preoperative ( P < 0. 01 ). Corneal endothelial cell density and percentage of hexagonal cells decreased, the variation coefficient increased in first week of postoperative, with no statistically significant differences when compared with the preoperative (P>0. 05) CONCLUSlON: lnnercapsular phacoemulsification combined with primary lOL implantation in the treatment of the whole lens dislocation (‖a and ‖b ) can restore function in patients with diplopia and control lOP effectively, reduce corneal endothelial cell damage, which is an effective method to treat the whole traumatic lens dislocation.

The cyclization of 2,3-oxidosqualene is the key branch point of ergosterol and triterpenoid biosynthesis. Downregulation of 2,3-oxidosqualene metabolic flux to ergosterol in Saccharomyces cerevisiae may redirect the metabolic flux toward the triterpenoid synthetic pathway. In our study, primers were designed according to erg7 gene sequence of S. cerevisiae. Three fragments including 5' long fragment, 5' short fragment and erg7 coding region fragment were amplified by PCR. 5' long fragment consists of the promoter and a part of erg7 coding region sequence. 5' short fragment consists of a part of promoter and a part of erg7 coding region sequence. These fragments were inserted reversely into pESC-URA to construct antisense expression plasmids. The recombinant plasmids were transformed into S. cerevisiae INVSc1 and recombinant strains were screened on the nutritional deficient medium SD-URA. The erg7 expression level of recombinant strains, which harbored antisense expression plasmid of erg7 coding region, was similar to that of INVScl by semi-quantitative PCR detection. But erg7 expression level of recombinant strains, which harbored 5' long antisense fragment and 5' short antisense fragment, was significantly lower than that of the control. The results of TLC and HPLC showed that the ergosterol content of recombinant strains, which harbored 5' long antisense fragment, decreased obviously. The ergosterol contents of the others were almost equal to that of INVSc1. Lanosterol synthase gene expression was downregulated by antisense RNA technology in S. cerevisiae, which lays a foundation for reconstructing triterpenoid metabolic pathway in S. cerevisiae by synthetic biology technology.
DNA Primers ; Down-Regulation ; Gene Expression ; Intramolecular Transferases ; genetics ; metabolism ; Plasmids ; Polymerase Chain Reaction ; RNA, Antisense ; Saccharomyces cerevisiae ; enzymology ; genetics ; Squalene ; analogs & derivatives ; metabolism ; Transformation, Genetic

BmK AngM1 is a long-chain scorpion toxin purified from the venom of Buthus martensii Karsch. It has been reported to exhibit evident analgesic effect and low toxicity, and has the potential to be a novel analgesic drug. The BmKAngM1 gene was transformed into Pichiapastoris GS115. Mut+ and Mut(s) recombinant strains were screened by phenotype and Mut+ recombinant strains were used to detect BmK AngMl gene copy number in the real-time PCR. Expression of BmK AngM1 in the Mut+ recombinant strain was compared with that of the Mut(s) recombinant strain with the same single copy of BmK AngM1 gene under the same condition. The results indicated that the transcription level of BmK AngM1 gene in the Mut(s) recombinant strain was 2.7 fold of that in the Mut recombinant strain in the real-time PCR, and the expression of BmK AngM 1 in the Mut(s) recombinant strain was 1.5 fold of that in the Mut+ recombinant strain. Therefore, Mut(s) recombinant strain showed better ability to express BmK AngM1 than Mut+ recombinant strain.
Animals ; Arthropod Proteins ; biosynthesis ; Gene Dosage ; Pichia ; metabolism ; Recombinant Proteins ; biosynthesis ; Scorpion Venoms ; chemistry

OBJECTIVETo investigate the relationship between phenotype transformation and biomechanical properties of detrusor smooth muscle cell (DSMC) subjected to the cyclic mechanical stretch.

METHODSCultured rat DSMCS were grown on collagen-coated silicone membranes and subjected to continuous cycles of stretch-relaxation. All experiments were made on cells between passage 2 and 4. Each cycle consists of 5-second stretch and 5-second relaxation. The computer controlled vacuum induced 10% (I), 20% (II) and 30% (III) maximum elongation of the plate membrane at different designed pressures. We assessed DNA synthesis rate using tritiated thymidine incorporation assay. Using immunofluorescent assay and flow cytometer, we analysed the expression of SM-alpha-actin and proliferation of DSMC. The image analysis and micropipette aspiration systems were employed to investigate the single cell contraction and viscoelasticity. The elastic modulus K(1), K(2) and viscoelastic coefficient micro were determined using the three-element standard linear solid model, thus demonstrating the passive deformation ability of detrusor cells.

RESULTSAs the basic structural changes to mechanical stretch, DSMCs underwent phenotypic modulation from their normal contractile phenotype to a "synthetic" phenotype: the DSMCs became more proliferative and the actin less organized along the cell's long axis. The cell proliferation index (CPI) of control and stretched group (10%, 20%, 30% elongation) were 0.24, 0.43, 0.58 and 0.65 respectively. After mechanical stretch, the well-spread filaments changed their orientation. Contraction and viscoelasticity of single DSMC subjected to stretch both decreased significantly compared to control. The Vmax and. DeltaLmax of group III (30% elongation) saw significant decreases compared with unstretched control (P < 0.01). K(1) and K(2) decreased with the increasing of mechanical overload, however, there was no statistic difference between groups II and group III.

CONCLUSIONSStructure determines function. Conversely, dysfunction implies the structural transformation. Functional abnormalities of BOO have the structural basis: phenotype transformation of detrusor cells. Cyclic stretch and relaxation applied to DSMCs in vitro can be used to model the increases in urodynamic load experienced by the bladder detrusor muscle under the conditions of bladder outlet obstruction. Phenotypic transformation is the structural basis of functional changes of DSMC subjected to periodic overload mechanical stretch.

Animals ; Biomechanical Phenomena ; DNA ; biosynthesis ; Muscle, Smooth ; physiology ; Phenotype ; Rats ; Rats, Wistar ; Stress, Mechanical ; Urinary Bladder ; physiology ; Urinary Bladder Neck Obstruction ; physiopathology