Quanzhen Yiqi decoction attenuates inflammation in mice with smoking-induced COPD by activating the Nrf2/HO-1 pathway and inhibiting the NLRP3 inflammasome.

OBJECTIVE: Quanzhen Yiqi decoction (QZYQ) is a traditional Chinese medicine for treating chronic obstructive pulmonary disease. METHODS: Mice were exposed to cigarette smoke (CS) 6 days/week (40 cigarettes/day) for 24 weeks and then intragastrically administered QZYQ (4.72, 9.45, or 18.89 g/kg) or dexamethasone (DEX, 0.6 mg/kg) for 6 weeks. We examined the lung function and collected bronchoalveolar lavage fluid for inflammatory cell and cytokine quantification. The pathological lung changes, ROS and oxidative biomarkers were measured. We used immunohistochemistry and western blotting to evaluate the levels of Nrf2/HO-1, NLRP3/ASC/Caspase1/IL-1ß/IL-18. RESULTS: The CS group showed significant increases in the forced vital capacity, lung resistance, and chord compliance and a lower FEV50/FVC compared with the control, and QZYQ improved these changes. In addition, QZYQ effectively reduced emphysema, immune cell infiltration, and airway remodeling. QZYQ stimulated HO-1 expression and reduced oxidative stress through the Nrf2 pathway. QZYQ inhibited the production of NLRP3/ASC/Caspase-1 to inhibit IL-1ß and IL-18. CONCLUSION: Our study suggested that QZYQ can improve the function and histology of the lungs and reduce inflammatory cell recruitment. QZYQ inhibits ROS production and NLRP3 inflammasome activation by upregulating Nrf2 to reduce lung injury. The anti-inflammatory effects of QZYQ are similar to those of DEX.

LncRNA AC125982.2 regulates apoptosis of cardiomyocytes through mir-450b-3p/ATG4B axis in a rat model with myocardial infarction.

Background: The occurrence and disability of myocardial infarction (MI) are on the rise globally, making it a significant contributor to cardiovascular mortality. Irreversible myocardial apoptosis plays a crucial role in causing MI. Long non-coding RNAs (LncRNAs) are key regulators of the cardiac remodeling process. Therefore, it is necessary to explore the effect of LncRNAs on cardiomyocyte apoptosis in MI. Methods: The rat-MI model was constructed, LncRNA-Seq and qPCR analyses were used to determine differentially expressed genes obtained from heart tissue of rats in the MI and sham groups. The miRanda software was used to predict the binding sites of LncRNA-miRNA and miRNA-mRNA, which were futhrer verified by dual luciferase assay. The LncRNA-miRNA-apoptosis pathway was further validated using hypoxia-exposed primary cardiomyocytes. Results: Compared to the sham group, 412 LncRNAs were upregulated and 501 LncRNAs were downregulated in MI-rat heart tissues. Among them, LncRNA AC125982.2 was most significantly upregulated in MI-rat heart tissues and hypoxic cardiomyocytes. Knockdown of AC125982.2 and ATG4B expression reversed hypoxia-induced apoptosis. In addition, transfection of mir-450b-3p inhibitor attenuated the protective effect of AC125982.2 knockdown. Moreover, we found that AC125982.2 modulated ATG4B expression by acting as a sponge for miR-450b-3p. Conclusion: Upregulated AC125982.2 expression regulates ATG4B by sponging miR-450b-3p, promoting cardiomyocyte apoptosis and contributing to rat MI development.

Fabrication of a magnetic metal-organic framework/covalent organic framework composite for simultaneous magnetic solid-phase extraction of seventeen trace quinolones residues in meats.

Effective capture of quinolones (QNs) in animal-derived food is a vital procedure for food safety monitoring. However, the lack of adsorption specificity and difficult to recycle in complex substrate conditions have been major problems for most of the adsorbents. In this work, a magnetic Fe3O4/MOF/COF composite (named Fe3O4@NH2-MIL-125@TpPa-SO3H) was successfully synthesized with good magnetic responsiveness and conspicuous affinity towards QNs. The Fe3O4/MOF/COF composite was used as a magnetic solid-phase extraction (MSPE) adsorbent for pretreatment and determination of QNs in meat samples. Under optimal MSPE conditions in combination with high performance liquid chromatography-quadrupole orbitrap high resolution mass spectrometer (HPLC-Q-Orbitrap HRMS), the proposed method had good linearity (R2 ≥ 0.9978) from 0.01 to 100ng g-1, low limits of detection (0.0016 to 0.0940ng g-1), good precision with relative standard deviations lower than 5.8%. This method was effectively applied to the detection of 17 QNs in the spiked pork, chicken and beef samples with satisfactory recoveries from 83.9 to 106.2%. The separation selectivity mainly due to the π-π interaction, hydrogen bonding, and electrostatic attraction between QNs and the sulfonic acid and amino functional groups of the composite. After verification, the stability and reusability of the composite meet the requirements of complex matrix sample pretreatment. The developed MSPE method based on the magnetic Fe3O4/MOF/COF composite provided an ideal sample pretreatment alternative for determining trace QNs in complex matrixes with selectivity, simplicity, rapidity, and efficiency.

New insights into breast microcalcification for poor prognosis: NACT cohort and bone metastasis evaluation cohort.

OBJECTIVES: The study aimed to analyze the poor prognosis of microcalcification in breast cancer (BC), including the pathological complete response (pCR) to neoadjuvant chemotherapy (NACT) and the risk of bone metastases. MATERIALS AND METHODS: 313 breast cancer patients received NACT to evaluate pCR and 1182 patients from a multicenter database to assess bone metastases were retrospectively included. Two groups were divided according to the presence or absence of mammography microcalcification. Clinical data, image characteristics, neoadjuvant treatment response, bone involvement, and follow-up information were recorded. The pCR and bone metastases were compared between subgroups using the Mann-Whitney and χ2 tests and logistic regression, respectively. RESULTS: Mammographic microcalcification was associated with a lower pCR than uncalcified BC in the NACT cohort (20.6% vs 31.6%, P = 0.029). Univariate and multivariate analysis suggested that calcification was a risk factor for poor NACT response [OR = 1.780, 95%CI (1.065-2.974), P = 0.028], [OR = 2.352, 95%CI (1.186-4.667), P = 0.014]. Microcalcification was more likely to be necrosis on MRI than those without microcalcification (53.0% vs 31.7%, P < 0.001), multivariate analysis indicated that tumor necrosis was also a risk factor for poor NACT response [OR = 2.325, 95%CI (1.100-4.911), P = 0.027]. Age, menopausal status, breast density, mass, molecular, and pathology type were not significantly associated with non-pCR risk assessment. In a multicenter cohort of 1182 patients with pathologically confirmed BC, those with microcalcifications had a higher proportion of bone metastases compared to non-calcified BC (11.6% vs 4.9%, P < 0.001). Univariate and multivariate analysis showed that microcalcification was an independent risk factor for bone metastasis [OR = 2.550, 95%CI (1.620-4.012), P < 0.001], [OR = 2.268(1.263-4.071), P = 0.006)]. Osteolytic bone metastases predominated but there was no statistical difference between the two groups (78.9% vs 60.7%, P = 0.099). Calcified BC was mainly involved in axial bone, but was more likely to involve the whole-body bone than non-calcified BC (33.8% vs 10.7%, P = 0.021). CONCLUSION: This study provides important insights into the poor prognosis of microcalcification, not only in terms of poor response to NACT but also the risk factor of bone metastases.

Integration of Human Protein Sequence and Protein-Protein Interaction Data by Graph Autoencoder to Identify Novel Protein-Abnormal Phenotype Associations.

Understanding gene functions and their associated abnormal phenotypes is crucial in the prevention, diagnosis and treatment against diseases. The Human Phenotype Ontology (HPO) is a standardized vocabulary for describing the phenotype abnormalities associated with human diseases. However, the current HPO annotations are far from completion, and only a small fraction of human protein-coding genes has HPO annotations. Thus, it is necessary to predict protein-phenotype associations using computational methods. Protein sequences can indicate the structure and function of the proteins, and interacting proteins are more likely to have same function. It is promising to integrate these features for predicting HPO annotations of human protein. We developed GraphPheno, a semi-supervised method based on graph autoencoders, which does not require feature engineering to capture deep features from protein sequences, while also taking into account the topological properties in the protein-protein interaction network to predict the relationships between human genes/proteins and abnormal phenotypes. Cross validation and independent dataset tests show that GraphPheno has satisfactory prediction performance. The algorithm is further confirmed on automatic HPO annotation for no-knowledge proteins under the benchmark of the second Critical Assessment of Functional Annotation, 2013-2014 (CAFA2), where GraphPheno surpasses most existing methods. Further bioinformatics analysis shows that predicted certain phenotype-associated genes using GraphPheno share similar biological properties with known ones. In a case study on the phenotype of abnormality of mitochondrial respiratory chain, top prioritized genes are validated by recent papers. We believe that GraphPheno will help to reveal more associations between genes and phenotypes, and contribute to the discovery of drug targets.

Qingfei Litan Decoction Against Acute Lung Injury/Acute Respiratory Distress Syndrome: The Potential Roles of Anti-Inflammatory and Anti-Oxidative Effects.

Acute lung injury/acute respiratory distress syndrome (ALI/ARDS) is an acute respiratory failure syndrome characterized by progressive arterial hypoxemia and dyspnea. Qingfei Litan (QFLT) decoction, as a classic prescription for the treatment of acute respiratory infections, is effective for the treatment of ALI/ARDS. In this study, the compounds, hub targets, and major pathways of QFLT in ALI/ARDS treatment were analyzed using Ultra high performance liquid chromatography coupled with mass spectrometry (UHPLC-MS) and systemic pharmacology strategies. UHPLC-MS identified 47 main components of QFLT. To explore its anti-inflammatory and anti-oxidative mechanisms, gene ontology (Go) analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment and network pharmacological analysis were conducted based on the main 47 components. KEGG enrichment analysis showed that TNF signaling pathway and Toll-like receptor signaling pathway may be the key pathways of ALI/ARDS. We explored the anti-inflammatory and anti-oxidative pharmacological effects of QFLT in treatment of ALI/ARDS in vivo and in vitro. QFLT suppressed the levels of proinflammatory cytokines and alleviated oxidative stress in LPS-challenged mice. In vitro, QFLT decreased the levels of TNF-α, IL-6, IL-1ß secreted by LPS-activated macrophages, increased GSH level and decreased the LPS-activated reactive oxygen species (ROS) in lung epithelial A549 cells. This study suggested that QFLT may have anti-inflammatory and anti-oxidative effects on ALI/ARDS, combining in vivo and in vitro experiments with systemic pharmacology, providing a potential therapeutic strategy option.

Influence of drying methods on the structure and properties of cellulose formate and its application as a reducing agent.

Cellulose formate (CF) with surface formyl groups can be prepared through the esterification between cellulose and formic acid (FA). The properties of CF are sensitive to temperature, which is of great importance for its end application. In this work, the effect of four drying methods on the structure and properties of the resultant CF was investigated. Results showed that the CF samples as special cellulose nanofibrils with cellulose II crystal form and fibrous structure were sensitive to drying temperature and drying time. The freeze-dried CF sample maintained its original structure, while the air-dried and oven-dried CF samples with amorphous structure showed the aggregation state. Furthermore, the CF/Ag composites were prepared using silver mirror reaction where the never dried CF was used as a reducing agent. SEM and TEM images exhibited a large number of Ag nanoparticles with the diameter of 20-50 nm on the surface of CF samples. As expected, the fabricated CF/Ag composites showed strong antibacterial activity against both Escherichia coli and Bacillus subtilis, and thus the prepared composites have great potential applications in antibacterial daily necessities and medical supplies.

Impact of the Incorporation of Nano-Sized Cellulose Formate on the End Quality of Polylactic Acid Composite Film.

Polylactic acid (PLA) films with good sustainable and biodegradable properties have been increasingly explored recently, while the poor mechanical property of PLA limits its further application. Herein, three kinds of nano-sized cellulose formate (NCF: cellulose nanofibril (CNF), cellulose nanocrystal (CNC), and regenerated cellulose formate (CF)) with different properties were fabricated via a one-step formic acid (FA) hydrolysis of tobacco stalk, and the influence of the properties of NCF with different morphologies, crystallinity index (CrI), and degree of substitution (DS) on the end quality of PLA composite film was systematically compared. Results showed that the PLA/CNC film showed the highest increase (106%) of tensile strength compared to the CNF- and CF-based films, which was induced by the rod-like CNC with higher CrI. PLA/CF film showed the largest increase (50%) of elongation at the break and more even surface, which was due to the stronger interfacial interaction between PLA and the CF with higher DS. Moreover, the degradation property of PLA/CNF film was better than that of other composite films. This fundamental study was very beneficial for the development of high-quality, sustainable packaging as an alternative to petroleum-based products.

Yangxinkang tablet protects against cardiac dysfunction and remodelling after myocardial infarction in rats through inhibition of AMPK/mTOR-mediated autophagy.

Context: Acute myocardial infarction (AMI) is defined as myocardial necrosis. Clinicians use the traditional Chinese patent medicine Yangxinkang Tablet (YXK) to treat chronic heart failure.Objective: To explore the effects of YXK on heart injury following AMI and the underlying mechanisms.Materials and methods: The AMI model was produced in Wistar rats by permanent ligation of the left anterior descending coronary artery. Rats were divided into the following five groups: Sham (n = 6), MI (Model, n = 10), AICAR (AMPK agonist, 50 mg/kg/d, i.p., n = 10), Compound C (AMPK inhibitor, 10 mg/kg/d, i.p., n = 10), and YXK (0.72 g/kg/d, gavage, n = 10) groups. Cardiac function, cardiac fibrosis, apoptosis, and expression of p-AMPK, p-mTOR, and autophagy-related proteins was measured after 4 weeks of treatment after the successful modelling of the AMI.Results: Compared to MI group, both YXK and AMPK inhibitor improved cardiac dysfunction and reduced cardiac fibrosis (15.6 ± 2.3; 22.6 ± 4.6 vs. 34.6 ± 4.3%) and myocardial cell apoptosis (12 ± 3.67; 25.6 ± 6.8 vs. 54 ± 4.8%). Futhermore, YXK and AMPK inhibitor significantly decreased p-AMPK expression by 11.05% and 14.64%, LC3II/I by 25.08% and 35.28% and Beclin-1 by 66.71% and 33.85%, increased p-mTOR by 22.14% and 47.46% and p62 by 70.83% and 18.58%.Conclusions: The underlying mechanism appears to include suppression of autophagy via inhibiting AMPK/mTOR signalling, suggesting that YXK may serve as a potentially effective Chinese herbal compound for suppressing cardiac fibrosis in heart injury.

The T296V Mutant of Amorpha-4,11-diene Synthase Is Defective in Allylic Diphosphate Isomerization but Retains the Ability To Cyclize the Intermediate (3R)-Nerolidyl Diphosphate to Amorpha-4,11-diene.

The T296V mutant of amorpha-4,11-diene synthase catalyzes the abortive conversion of the natural substrate (E,E)-farnesyl diphosphate mainly into the acyclic product (E)-ß-farnesene (88%) instead of the natural bicyclic sesquiterpene amorphadiene (7%). Incubation of the T296V mutant with (3R,6E)-nerolidyl diphosphate resulted in cyclization to amorphadiene. Analysis of additional mutants of amino acid residue 296 and in vitro assays with the intermediate analogue (2Z,6E)-farnesyl diphosphate as well as (3S,6E)-nerolidyl diphosphate demonstrated that the T296V mutant can no longer catalyze the allylic rearrangement of farnesyl diphosphate to the normal intermediate (3R,6E)-nerolidyl diphosphate, while retaining the ability to cyclize (3R,6E)-nerolidyl diphosphate to amorphadiene. The T296A mutant predominantly retained amorphadiene synthase activity, indicating that neither the hydroxyl nor the methyl group of the Thr296 side chain is required for cyclase activity.

Molecular cloning and functional analysis of a 10-epi-junenol synthase from Inula hupehensis.

Junenol based-eudesmanolides have been detected in many compositae plant species and were reported to exhibit various pharmacological activities. So far, the gene encoding junenol synthase has never been isolated. Here we report the molecular cloning and functional analysis of a 10-epi-junenol synthase from Inula hupehensis (designated IhsTPS1). IhsTPS1 converts the substrate farnesyl diphosphate into multiple sesquiterpenes with the product 10-epi-junenol being predominant. The transcript levels of IhsTPS1 correlate well with the accumulation pattern of 10-epi-junenol in I. hupehensis organs, supporting its biochemical roles in vivo.

Identification and Functional Characterization of Sesquiterpene Synthases from Xanthium strumarium.

Xanthium strumarium synthesizes various pharmacologically active sesquiterpenes. The molecular characterization of sesquiterpene biosynthesis in X. strumarium has not been reported so far. In this study, the cDNAs coding for three sesquiterpene synthases (designated as XsTPS1, XsTPS2 and XsTPS3) were isolated using the X. strumarium transcriptome that we recently constructed. XsTPS1, XsTPS2 and XsTPS3 were revealed to have primary activities forming germacrene D, guaia-4,6-diene and germacrene A, respectively, by either ectopic expression in yeast cells or purified recombinant protein-based in vitro assays. Quantitative real-time PCRs and metabolite analysis for the different plant parts showed that the transcript abundance of XsTPS1-XsTPS3 is consistent with the accumulation pattern of their enzymatic products, supporting their biochemical functions in vivo. In particular, we discovered that none of the XsTPS2 product, guaia-4,6-diene, can be detected in one of the X. strumarium cultivars used in this study (it was named the Hubei-cultivar), in which a natural deletion of two A bases in the XsTPS2 cDNA disrupts its activity, which further confirmed the proposed biochemical role of XsTPS2 in X. strumarium in vivo.

Histone H2B gene cloning, with implication for its function during nuclear shaping in the Chinese mitten crab, Eriocheir sinensis.

Spermatogenesis in animals is the process by which male spermatogonia develop into mature spermatozoa. In most taxa, the process involves changes in the basic proteins associated with DNA. Somatic-type histones are partially or totally replaced by transition proteins, which in turn are replaced by protamines producing compact packaging of the genome. Sperm chromatin in the Chinese mitten crab (Eriocheir sinensis) has a noncompacted loosely arranged organization. However, its formation during spermatogenesis is not clear. In this study, a cDNA sequence encoding histone H2B was cloned by polymerase chain reaction amplification, and its recombinant protein was expressed and purified. Protein alignment studies demonstrated that this histone H2B had 80.80%, 95.12%, 80.16%, 91.87%, 81.75%, 77.78% and 99.19% identity with its counterparts in zebrafish, fruit fly, human, prawn, mouse, African clawed frog, and crayfish, respectively. Western blotting indicated that the recombinant protein could be recognized by an anti-H2B antibody and confirmed that histone H2B exists in sperm nuclei. Immunofluorescence demonstrated that histone H2B was present in the nuclei of spermatogonia, spermatocytes, spermatids, and mature spermatozoa. This is the first report that the mature sperm nucleus of E. sinensis contains histone H2B. This work complements a previous study of sperm histones of this species and provides a basis for further study of the noncondensed sperm nuclei of decapod crustaceans.

Cloning and characterization of AabHLH1, a bHLH transcription factor that positively regulates artemisinin biosynthesis in Artemisia annua.

Amorpha-4,11-diene synthase (ADS) and Cyt P450 monooxygenase (CYP71AV1) in Artemisia annua L. are two key enzymes involved in the biosynthesis of artemisinin. The promoters of ADS and CYP71AV1 contain E-box elements, which are putative binding sites for basic helix-loop-helix (bHLH) transcription factors. This study successfully isolated a bHLH transcription factor gene from A. annua, designated as AabHLH1, from a cDNA library of the glandular secretory trichomes (GSTs) in which artemisinin is synthesized and sequestered. AabHLH1 encodes a protein of 650 amino acids containing one putative bHLH domain. AabHLH1 and ADS genes were strongly induced by ABA and the fungal elicitor, chitosan. The transient expression analysis of the AabHLH1-green fluorescent protein (GFP) reporter gene revealed that AabHLH1 was targeted to nuclei. Biochemical analysis demonstrated that the AabHLH1 protein was capable of binding to the E-box cis-elements, present in both ADS and CYP71AV1 promoters, and possessed transactivation activity in yeast. In addition, transient co-transformation of AabHLH1 and CYP71AV1Pro::GUS in A. annua leaves showed a significant activation of the expression of the GUS (ß-glucuronidase) gene in transformed A. annua, but mutation of the E-boxes resulted in abolition of activation, suggesting that the E-box is important for the CYP71AV1 promoter activity. Furthermore, transient expression of AabHLH1 in A. annua leaves increased transcript levels of the genes involved in artemisinin biosynthesis, such as ADS, CYP71AV1 and HMGR. These results suggest that AabHLH1 can positively regulate the biosynthesis of artemisinin.

[Metabolic engineering of terpenoids in plants].

Terpenoids are present in all organisms but are especially abundant in plants, with more than 30,000 compounds. Not only do they play an important role in the life of plant, but also have high commercial values. However, the content of many important terpenoids in plant is very low. Therefore, how to improve the inefficient production of terpenoids is an urgent task. Metabolic engineering has been one of the most potential technologies to improve terpenoids production in recent years, following the study of metabolic pathway and regulation mechanism of terpenoids. Although there are some breakthroughs, metabolic engineering of terpenoids is still full of challenges because of the lack of knowledge on metabolic control of most terpenoids. Functional genomics approaches, including transcriptomics, proteomics and metabolomics, are potential tools for exploring of metabolic engineering. Integrating transcriptomics and metabolomics is an effective way to discover new genes involved in metabolic pathway. In this paper, the representative research outcomes about the metabolic engineering of terpenoids in plant were reviewed concisely and then the application of functional genomics approaches to study metabolic pathway and regulation mechanism of terpenoids and the strategies for metabolic engineering of terpenoids were discussed.

Isolation and characterization of Scophthalmus maximus rhabdovirus.

A rhabdovirus associated with a lethal hemorrhagic disease in cultured turbot Scophthalmus maximus Linnaeus was isolated. The virus induced typical cytopathogenic effects (CPE) in 9 of 15 fish cell lines examined and was then propagated and isolated from infected carp leucocyte cells (CLC). Electron microscopy observations revealed that the negatively stained virions had a typical bullet-shaped morphology with one rounded end and one flat base end. The bullet-shaped morphology was more obvious and clear in ultrathin sections of infected cells. Experimental infections also indicated that the S. maximus rhabdovirus (SMRV) was not only a viral pathogen for cultured turbot, but also had the ability to infect other fish species, such as freshwater grass carp. A partial nucleotide sequence of the SMRV polymerase gene was determined by RT-PCR using 2 pairs of degenerate primers designed according to the conserved sequences of rhabdovirus polymerase genes. Homology analysis, amino acid sequence alignment, and phylogenetic relationship analysis of the partial SMRV polymerase sequence indicated that SMRV was genetically distinct from other rhabdoviruses. Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) analysis of the purified SMRV revealed 5 major structural proteins, and their molecular masses were estimated to be about 250, 58, 47, 42, and 28 kDa. Significant serological reactivity differences were also observed between SMRV and its nearest neighbor, spring viremia of carp virus (SVCV). The data suggest that SMRV is likely a novel fish rhabdovirus, although it is closely related to rhabdoviruses in the genus Vesiculovirus.

Molecular cloning and overexpression of a novel UDP-glucosyltransferase elevating salidroside levels in Rhodiola sachalinensis.

Salidroside is a novel effective adaptogenic drug extracted from the medicinal plant Rhodiola sachalinensis A. Bor. Because this plant is a rare resource and has low yield, there is great interest in enhancing the production of salidroside. In this study, a putative UDP-glucosyltransferase (UGT) cDNA, UGT73B6, was isolated from Rhodiola sachalinensis using a rapid amplification of cDNA ends (RACE) method. The cDNA was 1,598 bp in length encoding 480 deduced amino acid residues with a conserved UDP-glucose-binding domain (PSPG box). Southern blot analysis of genomic DNA indicated that UGT73B6 existed as a single copy gene in the R. sachalinensis genome. Northern blot analysis revealed that transcripts of UGT73B6 were present in roots, calli and stems, but not in leaves. The UGT73B6 under 35S promoter with double-enhancer sequences from CaMV-Omega and TMV-Omega fragments was transferred into R. sachalinensis via Agrobacterium tumefaciens. PCR, PCR-Southern and Southern blot analyses confirmed that the UGT73B6 gene had been integrated into the genome of transgenic calli and plants. Northern blot analysis revealed that the UGT73B6 gene had been expressed at the transcriptional level. High performance liquid chromatography (HPLC) analysis indicated that the overexpression of the UGT73B6 gene resulted in an evident increase of salidroside content. These data suggest that the cloned UGT73B6 can regulate the conversion of tyrosol aglycon to salidroside in R. sachalinensis. This is the first cloned glucosyltransferase gene involved in salidroside biosynthesis.

[Advances in sesquiterpene synthases cyclases of Artemisia annua].

Artemisinin,a new and a very potent antimalarial drug, is produced by the plant Artemisia annua L. with a very low yield ranging from 0.01% to 0.8% on a dry-weight basis. This makes artemisinin an expensive drug. Several studies reported chemical synthesis of the artemisinin, but none of them seems a viable economical alternative compared with the isolation of artemisinin from the plant. Hence, a higher artemisinin concentration in the plant is necessary for cheap antimalarial drug production. Many types of cyclic sesquiterpenes in Artemisia annua have been characterized to date, each derived from the common cyclic precursor FDP in a reaction catalyzed by a sesquiterpene synthase. Sesquiterpene synthases are widely regarded as the rate-determining regulatory enzymes in the pathways they participate, and a number of sesquiterpene synthases have been cloned from Artemisia annua up to now. This report is a brief review on the following sesquiterpene synthases: epi-cedrol synthase, amorpha-4,11-diene synthase, beta-caryophyllene synthase, (E)-beta-farnesene synthase, germacrene A synthase, as well as a new sesquiterpene synthase whose function remains largely unknown. The report is of help for a better understanding of metabolic engineering of Artemisia annua.

[Advances in molecular regulation of artemisinin biosynthesis].

Artemisinin, a new and a very potent antimalarial drug, is produced by the Chinese medicinal herb Artemisia annua L. It is a sesquiterpene lactone with an endoperoxide bridge and is active against chloroquine resistant forms of Plasmodium falciparum. The relatively low yield (0.01% - 0.6%) of artemisinin in A. annua is a serious limitation to the commercialization of the drug. Therefore, a through understanding of the biosynthetic pathway and the characterization of the involved enzymes are important for the biology production of artemisinin. This review is focused on the recent progress in the molecular regulation of artemisinin biosynthesis from the following aspects: the biosynthetic pathway of artemisinin, the key enzymes involved in artemisinin biosynthesis, and the molecular regulation of artemisinin biosynthesis. The biosynthetic pathway of artemisinin belongs to the isoprenoid metabolite pathway, the key enzymes involved in the biosynthesis of artemisinin include: 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR), farnesyl diphosphate synthase (FDPS), and amorpha-4, 11-diene synthase, of which amorpha-4, 11-diene synthase catalyzes the cyclisation of the ubiquitous precursor farnesyl diphosphate to the highly specific olefinic sesquiter-pene skeletons and has been postulated as the regulatory step in the biosynthesis of artemisinin. Recently the gene encoding of the amorpha-4, 11-diene synthase has been cloned and the functional expressions have been studied by several research teams, therefore, the breakthroughs in production of artemisinin could hopefully be achieved by metabolic engineering of the plant, in particular, by over-expressing enzyme(s) catalyzing the rate limiting step(s) of artemisinin biosynthesis or by inhibiting the enzyme(s) of other pathway competing for its precursors. Besides, the effects of the heterogenesis isoprenoid pathway related genes on artemisinin biosynthesis of the transformed plants were also discussed.

Infection and propagation of lymphocystis virus isolated from the cultured flounder Paralichthys olivaceus in grass carp cell lines.

The causative agent of lymphocystis disease that frequently occurs in cultured flounder Paralichthys olivaceus in China is lymphocystis virus (LV). In this study, 13 fish cell lines were tested for their susceptibility to LV. Of these, 2 cell lines derived from the freshwater grass carp Ctenopharyngodon idellus proved susceptible to the LV, and 1 cell line, GCO (grass carp ovary), was therefore used to replicate and propagate the virus. An obvious cytopathic effect (CPE) was first observed in cell monolayers at 1 d post-inoculation, and at 3 d this had extended to about 75% of the cell monolayer. However, no further CPE extension was observed after 4 d. Cytopathic characteristics induced by the LV were detected by Giemsa staining and fluorescence microscopic observation with Hoechst 33258 staining. The propagated virus particles were also observed by electron microscopy. Ultrastructure analysis revealed several distinct cellular changes, such as chromatin compaction and margination, vesicle formation, cell-surface convolution, nuclear fragmentation and the occurrence of characteristic 'blebs' and cell fusion. This study provides a detailed report of LV infection and propagation in a freshwater fish cell line, and presents direct electron microscopy evidence for propagation of the virus in infected cells. A possible process by which the CPEs are controlled is suggested.