Strategies for efficient production of recombinant proteins in Escherichia coli: alleviating the host burden and enhancing protein activity.

Escherichia coli, one of the most efficient expression hosts for recombinant proteins (RPs), is widely used in chemical, medical, food and other industries. However, conventional expression strains are unable to effectively express proteins with complex structures or toxicity. The key to solving this problem is to alleviate the host burden associated with protein overproduction and to enhance the ability to accurately fold and modify RPs at high expression levels. Here, we summarize the recently developed optimization strategies for the high-level production of RPs from the two aspects of host burden and protein activity. The aim is to maximize the ability of researchers to quickly select an appropriate optimization strategy for improving the production of RPs.

Universal and unique strategies for the production of polyunsaturated fatty acids in industrial oleaginous microorganisms.

Polyunsaturated fatty acids (PUFAs), especially docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA) and arachidonic acid (ARA), are beneficial for reducing blood cholesterol and enhancing memory. Traditional PUFA production relies on extraction from plants and animals, which is unsustainable. Thus, using microorganisms as lipid-producing factories holds promise as an alternative way for PUFA production. Several oleaginous microorganisms have been successfully industrialized to date. These can be divided into universal and specialized hosts according to the products range of biosynthesis. The Yarrowia lipolytica is universal oleaginous host that has been engineered to produce a variety of fatty acids, such as γ-linolenic acid (GLA), EPA, ARA and so on. By contrast, the specialized host are used to produce only certain fatty acids, such as ARA in Mortierella alpina, EPA in Nannochloropsis, and DHA in Thraustochytrids. The metabolic engineering and fermentation strategies for improving PUFA production in universal and specialized hosts are different, which is the subject of this review. In addition, the widely applicable strategies for microbial lipid production that are not specific to individual hosts were also reviewed.

Exploring the Potential Mechanisms of Danshen for the Treatment of Ulcerative Colitis based on Serum Pharmacochemistry, Gene Expression Profiling, and Network Pharmacology: Regulation of Cell Apoptosis and Inflammatory Response.

BACKGROUND: As a traditional Chinese medicine, Danshen shows potential efficacy for treating ulcerative colitis (UC). However, the bioactive components and mode of action were unclear. AIM OF THIS STUDY: This paper uses a combination of network pharmacology, serum medicinal chemistry, and gene expression profiling to clarify its possible molecular mechanism of action and material basis. METHODS: Ultra-high performance liquid chromatography-mass spectrometry (UPLC-MS) was utilized to analyze the herbal components and metabolites from the serum of Danshen-treated mice. Gene expression profiles were applied to construct a database of Danshen action targets. Then, active ingredient-target-biological functional module networks were constructed to analyze the mechanism of action. Molecular docking has further confirmed the possibility of its components to the targets. RESULTS: As a result, 193 common targets between 1684 Danshen-related DEGs and 1492 UC targets were determined as the potential targets for Danshen in treatment with UC. Serum pharmacochemistry and target prediction showed that 22 components in serum acted on 777 targets. Intersection with common targets yielded 46 core targets, and an active ingredienttarget- biological functional module network was constructed for analysis. Network prediction and molecular docking results showed that the main action modules were inflammatory response and cell apoptosis, which mainly acted on targets SRC, RELA, HSP90AA1, CTNNB1, STAT3, and CASP3. The main components of Danshen intervention in UC were predicted to include Catechol, 3,9-Dimethoxypterocarpan, 8-Prenylnaringenin, Isoferulic acid, Salvianolic acid C, and Danshensu. CONCLUSION: The present study provides a scientific foundation for further explicating the mechanisms of Danshen against UC.

Economical downstream processing of microbial polyunsaturated fatty acids.

Polyunsaturated fatty acids (PUFAs) are important nutrients for humans and animals. Microorganisms, such as yeast, filamentous fungi, and microalgae, have successfully been modified to produce PUFAs. Apart from strain improvement and fermentation optimization, efficient and cost-effective downstream processing will determine whether production can advance from the laboratory to the factory.

Comprehensive survey of target prediction web servers for Traditional Chinese Medicine.

Traditional Chinese medicine (TCM) is characterized by multi-components, multiple targets, and complex mechanisms of action and therefore has significant advantages in treating diseases. However, the clinical application of TCM prescriptions is limited due to the difficulty in elucidating the effective substances and the lack of current scientific evidence on the mechanisms of action. In recent years, the development of network pharmacology based on drug systems research has provided a new approach for understanding the complex systems represented by TCM. The determination of drug targets is the core of TCM network pharmacology research. Over the past years, many web tools for drug targets with various features have been developed to facilitate target prediction, significantly promoting drug discovery. Therefore, this review introduces the widely used web tools for compound-target interaction prediction databases and web resources in TCM pharmacology research, and it compares and analyzes each web tool based on their basic properties, including the underlying theory, algorithms, datasets, and search results. Finally, we present the remaining challenges for the promising future of compound-target interaction prediction in TCM pharmacology research. This work may guide researchers in choosing web tools for target prediction and may also help develop more TCM tools based on these existing resources.

Vitex rotundifolia L. f. and Vitex trifolia L.: A review on their traditional medicine, phytochemistry, pharmacology.

ETHNOPHARMACOLOGICAL RELEVANCE: Vitex rotundifolia L. f. and Vitex trifolia L. belong to the genus Vitex, and Vitex rotundifolia L. f. evolved from Vitex trifolia L. Both are essential ethnic medicinal plants with a long history, commonly used to treat headaches, fever, diarrhea, hair loss, wound recovery, and other diseases. AIM OF THE REVIEW: The research status of Vitex trifolia L. and its relative species Vitex rotundifolia L. f. were reviewed from the aspects of traditional medicinal use, phytochemistry, and pharmacological activities, to provide a reference for the further development and utilization of Vitex rotundifolia L. f. and Vitex trifolia L. MATERIALS AND METHODS: In this paper, a comprehensive search of published literature was conducted through various books and online databases to obtain relevant information on Vitex rotundifolia L. f. and Vitex trifolia L. The search terms "(Vitex rotundifolia) OR (Vitex trifolia) OR (Fructus viticis)" were entered in PubMed, Web of Science, China national knowledge infrastructure (CNKI), Wanfang Data, Baidu Scholar, respectively. In addition to setting the year threshold of "2018-2022" on Baidu Scholar, other databases searched all fields and found 889, 283, 1263, 1023, and 147 articles, respectively. Among them, review, repetition, overlapping data, and other reasons were excluded, and finally, a total of 164 articles were included in the review study. RESULTS: A total of 369 compounds have been identified, including 159 terpenoids, 51 flavonoids, 83 phenylpropanoids, and 76 other compounds. Pharmacological studies have shown that Vitex rotundifolia L. f. and Vitex trifolia L. have a variety of pharmacological activities, such as anti-tumor, analgesic, antipyretic, anti-inflammatory, antioxidant, antibacterial, and estrogen-like activity. Modern clinical use for treating cold headaches, diarrhea dysentery, irregular menstruation, and other diseases. CONCLUSIONS: As traditional medicinal plants, Vitex rotundifolia L. f. and Vitex trifolia L. have wealthy chemical constituents and extensive pharmacological activities and are widely used in clinical practice from traditional to modern times. However, the research on the pharmacological activities of Vitex rotundifolia L. f. and Vitex trifolia L. is not in-depth, and the potential active components still need to be explored.

Application of Adaptive Laboratory Evolution in Lipid and Terpenoid Production in Yeast and Microalgae.

Due to the complexity of metabolic and regulatory networks in microorganisms, it is difficult to obtain robust phenotypes through artificial rational design and genetic perturbation. Adaptive laboratory evolution (ALE) engineering plays an important role in the construction of stable microbial cell factories by simulating the natural evolution process and rapidly obtaining strains with stable traits through screening. This review summarizes the application of ALE technology in microbial breeding, describes the commonly used methods for ALE, and highlights the important applications of ALE technology in the production of lipids and terpenoids in yeast and microalgae. Overall, ALE technology provides a powerful tool for the construction of microbial cell factories, and it has been widely used in improving the level of target product synthesis, expanding the range of substrate utilization, and enhancing the tolerance of chassis cells. In addition, in order to improve the production of target compounds, ALE also employs environmental or nutritional stress strategies corresponding to the characteristics of different terpenoids, lipids, and strains.

Efficient Biosynthesis of Odd-Chain Fatty Acids via Regulating the Supply and Consumption of Propionyl-CoA in Schizochytrium sp.

Odd chain fatty acids (OCFAs) are high-value-added compounds with great application in the field of food and medicine. As an oleaginous microorganism, Schizochytrium sp. has the potential to produce OCFAs efficiently. Propionyl-CoA is used as a precursor to synthesize OCFAs through the fatty acid synthetase (FAS) pathway, so its flow direction determines the yield of OCFAs. Here, different substrates were assessed to promote propionyl-CoA supply for OCFA accumulation. Moreover, the methylmalonyl-CoA mutase (MCM) was identified as the key gene responsible for propionyl-CoA consumption, which promotes the propionyl-CoA to enter into the tricarboxylic acid cycle rather than the FAS pathway. As one of the classic B12-dependent enzymes, the activity of MCM can be inhibited in the absence of B12. As expected, the OCFA accumulation was greatly increased. However, the removal of B12 caused growth limitation. Furthermore, the MCM was knocked out to block the consumption of propionyl-CoA and to maintain cell growth; results showed that the engineered strain achieved the OCFAs titer of 2.82 g/L, which is 5.76-fold that of wild type. Last, a fed-batch co-feeding strategy was developed, resulting in the highest reported OCFAs titer of 6.82 g/L. This study provides guidance for the microbial production of OCFAs.

Powerful Microbial Base-Editing Toolbox: From Optimization Strategies to Versatile Applications.

Base editors (BE) based on CRISPR systems are practical gene-editing tools which continue to drive frontier advances of life sciences. BEs are able to efficiently induce point mutations at target sites without double-stranded DNA cleavage. Hence, they are widely employed in the fields of microbial genome engineering. As applications of BEs continue to expand, the demands for base-editing efficiency, fidelity, and versatility are also on the rise. In recent years, a series of optimization strategies for BEs have been developed. By engineering the core components of BEs or adopting different assembly methods, the performance of BEs has been well optimized. Moreover, series of newly established BEs have significantly expanded the base-editing toolsets. In this Review, we will summarize the current efforts for BE optimization, introduce several novel BEs with versatility, and look forward to the broadened applications for industrial microorganisms.

[Isolation, purification and characterization of endothelial cells from endometrial cancer and normal endometrial tissue].

OBJECTIVE: To immunopurify human endometrial endothelial cells (HEEC) from fresh surgical specimens of endometrial cancers and normal endometrial tissues, and investigate their biological characteristics. METHODS: Endothelial cells of endometrial cancers and normal endometrial tissues were isolated using anti-CD31 conjugated magnetic microbeads. The isolated endothelial cells were cultured in vitro and their origins were identified. Their angiogenic characteristics were observed by MTT, wound healing, Transwell cell invasion and tube formation assays. RESULTS: Flow cytometry revealed that the immunopurification technique yielded endothelial cell purity of > 95% in all samples. All purified HEEC were characterized as endothelial cells on the basis of expression of the classical endothelial markers vWF and CD31 as shown by immunofluorescence examination. Although the tumor-associated HEEC didn't show more rapid proliferation than normal HEEC, they exhibited enhanced migration ability (P = 0.006), potent invasiveness (P = 0.033), and elevated tube formation in vitro (P = 0.029). CONCLUSIONS: Human endometrial endothelial cells can be efficiently isolated from endometrial cancer and normal endometrial tissues by immunomagnetic methods. Tumor-associated HEEC exhibit enhanced migratory ability, potent invasiveness, and elevated tube formation in vitro.

[Angiogenesis related gene expression profiles of human endometrial endothelial cells isolated from tissue of endometrial cancer].

OBJECTIVE: To identify and verify the different genes expression pattern between human endometrial endothelial cells (HEEC) isolated from endometrial cancer and normal endometrium. METHODS: Endothelial cells were isolated from 5 patients with endometrial cancer (endometrial cancer group 1) and 5 patients with normal endometria tissue (control group 1) admitted from June to November 2007 in Shandong Cancer Hospital. Global expression patterns of endothelial cells were examined using oligonucleotide microarrays. Tissues from 36 patients with endometrial cancer (endometrial cancer group 2) and 10 normal endometrial tissues (control group 2) admitted from January 2007 to April 2008 were selected to verify the expression of different genes, in which up-regulated genes including ESM1, MMP-10, SPP1 and HMGB1 were tested by quantitative real-time PCR and immunohistochemistry. RESULTS: Microarray analyses revealed 317 genes that exhibited > 2-fold or < 0.5 differences were identified (including 191 genes up-regulated and 126 down-regulated). Pathway analysis showed that these genes involved cell cycle, cell adhesion molecules, and extracellular matrix-receptor interaction were obviously predominant. Of them, 97 up-regulated genes and 44 down-regulated genes were related to angiogenesis. The mRNA expression of ESM1, MMP-10, SPP1 and HMGB1 in endometrial cancer group 2 were 0.898, 3.890, 1.433 and 1.881, respectively. Positive expression of SPP1, MMP-10, ESM1 and HMGB1 was observed in endometrial cancer group 2. However, the SPP1, ESM1 and HMGB1 was negative expressed in control group 2. CONCLUSION: It shows that there are the different angiogenesis related genes between endometrial cancer and normal endothelium, which will provide insights into the anti-angiogenesis therapy for endometrial cancers.

Antibacterial Activity Prediction Model of Traditional Chinese Medicine Based on Combined Data-Driven Approach and Machine Learning Algorithm: Constructed and Validated.

Traditional Chinese medicines (TCMs), as a unique natural medicine resource, were used to prevent and treat bacterial diseases in China with a long history. To provide a prediction model of screening antibacterial TCMs for the design and discovery of novel antibacterial agents, the literature about antibacterial TCMs in the China National Knowledge Infrastructure (CNKI) and Web of Science database was retrieved. The data were extracted and standardized. A total of 28,786 pieces of data from 904 antibacterial TCMs were collected. The data of plant medicine were the most numerous. The result of association rules mining showed a high correlation between antibacterial activity with cold nature, bitter and sour tastes, hemostatic, and purging fire efficacies. Moreover, TCMs with antibacterial activity showed a specific aggregation in the phylogenetic tree; 92% of them came from Tracheophyta, of which 74% were mainly concentrated in rosids, asterids, Liliopsida, and Ranunculales. The prediction models of anti-Escherichia coli and anti-Staphylococcus aureus activity, with AUC values (the area under the ROC curve) of 77.5 and 80.0%, respectively, were constructed by the Neural Networks (NN) algorithm after Bagged Classification and Regression Tree (Bagged CART) and Linear Discriminant Analysis (LDA) selection. The in vitro experimental results showed the prediction accuracy of these two models was 75 and 60%, respectively. Four TCMs (Cirsii Japonici Herba Carbonisata, Changii Radix, Swertiae Herba, Callicarpae Formosanae Folium) were proposed for the first time to show antibacterial activity against E. coli and/or S. aureus. The results implied that the prediction model of antibacterial activity of TCMs based on properties and families showed certain prediction ability, which was of great significance to the screening of antibacterial TCMs and can be used to discover novel antibacterial agents.

Localisation and expression of aquaporin subtypes in epithelial ovarian tumours.

To characterise AQP subtype localisation and expression in epithelial ovarian tumours, immunohistochemistry was used to assess the localisation and expression of AQP1-9 in 30 benign tumour cases, 30 borderline tumour cases, 50 malignant tumour cases and 20 normal ovarian tissue cases. Multiple AQP subtypes were expressed in epithelial ovarian tumours, with each AQP subtype displaying a different pattern of localisation and expression. AQP1 was mainly expressed in the microvascular endothelium, and AQP 2-9 were mainly expressed in tumour cells. Most AQP subtypes co-localised in the basolateral membranes of the epithelia of benign tumours and plasma membranes of malignant tumour cells. The positive rates for AQP1, 5, 6, 7, 8, and 9 were over 50%, but those for AQP2, 3 and 4 were only 10-40%. The expression of AQP1, 5 and 9 in malignant and borderline tumours was significantly higher than that in benign tumours (P<0.05) and normal ovarian tissue (P<0.05). However, AQP6 expression in ovarian malignant and borderline tumours was significantly lower than that in benign tumours (P<0.01) or normal ovarian tissue (P<0.01). AQP1 expression was increased in cases with ascites volumes greater than 1000 mL (P<0.05), AQP5 expression was greater in cases with lymph node metastasis (P<0.05), and more AQP9 expression was observed in G3 cases versus G1 and G2 cases (P<0.01). These results suggest that changes in the distribution and expression of AQP subtypes may be involved in ovarian carcinogenesis. This study presents a novel avenue of research that could illuminate the mechanism of ovarian carcinogenesis and treatment.