Objective: To study the protective effect of copper nanoparticles (Cu-nps) on the neurovascular units(NVU) after ischemic stroke. Methods: Cu-nps was synthesized by heating and stirring method. A model of rat transient middle cerebral artery occlusion/ reperfusion (tMCAO) was established in vivo. The experiment was divided into three groups, including normal group (Sham), model group (tMCAO), and dosing group (Cu-nps). Brain infarction area, neural apoptosis, blood-brain barrier (BBB) integrity, and related protein expression were detected in each group. Results: Cu-nps were successfully prepared and present in the form of Cu2+ with a uniform particle size around 80 nm and good biocompatibility. Cu-nps target damaged neurons in cerebral ischemia, improve neuronal cell viability, reduce reactive oxygen species (ROS), reduce neuronal apoptosis and cerebral infarct area, and reduce EB dye leakage and inflammatory cytokine expression. Conclusion: Cu-nps reduce cerebral ischemia-reperfusion injury, protect BBB integrity, reduce oxidative stress, protect NVU function and therefore reduce glial cell activation.
Objective: The pmr1 gene encodes P-type calcium-transporting ATPase Pmr1, which is involved in maintaining cell wall integrity and regulating cytokinesis. In this study, fission yeast was used as a model cell to explore the effects of pmr1 deletion on the sexual reproduction and dynamics of actin rings during cell mitosis, and to reveal the key genes and metabolic pathways of abnormal cell mitosis after pmr1 deletion. Methods: The effects of pmr1 deletion on cell mitosis and sexual reproduction were detected by cell growth rate measurement, spore production observation and statistics, green fluorescent protein-labeled monitoring and living cell imaging; The wild-type and pmr1Δ strain were sequenced by RNA-Seq and analyzed by bioinformatics, and verified by qRT-PCR. Results: The pmr1 deletion could slow down cell growth, decrease cell length in mitosis, increase length of sexually reproductive ascospore, and increase formation time of actin ring. RNA-sequencing results revealed that down-regulation of mfm1, mfm2 and mat1-Mc, up-regulation of cdc1 and exo1 in the mismatch repair pathway, and down-regulation of pgi1, pfk1 and dld1 in the glycolysis/gluconeogenesis pathway are the main factor of the increased spore length in the pmr1Δ; Meanwhile, the down-regulation of tdh1 and pgk1 in the glycolysis/gluconeogenesis pathway and the down-regulation of fas1, fas2, cut6 and lcf1 in the fatty acid anabolic pathway also led to the decreased cell length in mitosis of pmr1Δ; The up-regulation of hsp9 is the key gene that affected the formation time of actin ring in pmr1Δ. qRT-PCR experiments confirmed that the expression trends of key genes after pmr1 deletion were consistent with the RNA-Seq results. Conclusion: After pmr1 deletion, the mismatch repair pathway, glycolysis/gluconeogenesis pathway and fatty acid anabolic pathway are hindered in fission yeast cells, resulting in abnormal cell and spore morphology, obstruction of actin ring formation, and slowing down of cell proliferation.
Objective: Cardiovascular diseases caused by thrombus have severely impaired human health. However, there are most of defects on traditional thrombolytic agents, like high price, low fibrin specificity and side effect. Enzyme from marine environment are rarely reported and expected to be efficient and economical thrombolytic drugs. Methods: In this experiment, a mutant strain PW6-3 with high fibrinolytic activity was obtained by UV mutagenesis using the marine-derived Bacillus subtilis LC6-1. The acquire mutant PW6-3 was subjected to process optimization of fibrinolytic enzyme production. Results: The UV-mutagenized high-yielding mutant strain PW6-3 was (6 960.21 ± 85.51) U/mL, which was 30.48% higher than the initial strain. The medium components and culture conditions of strain PW6-3 in shake-flask were optimized by single factor and orthogonal experiments. The optimal medium components were: Corn starch 30 g/L, corn pulp dry powder 40 g/L, CaCl2 3g/L. The optimal culture conditions were: Temperature of 32℃, speed of 200 r/min, loading volume of 50 mL in 250 mL flask, inoculation volume of 3% (v/v), initial pH of 6.5, seed age of 18 h, fermentation time of 66 h. Conclusion: After fermentation optimization, the enzyme activity of strain PW6-3 reached (9 203.63 ± 67.85) U/mL, which was 72.53% higher than initial strain LC6-1. The optimized yield is at a high level in the world at present.
Over the last decade, Chimeric Antigen Receptor T-cell Immunotherapy(CAR-T) has become one of the promising strategies in tumor immunotherapy. This technique has been successfully applied in the treatment of various blood tumors. However, CAR-T therapy has made slow progress in the treatment of solid tumors, facing many challenges such as limitation of tumor microenvironment, cytokine release syndrome and severe off-target effect. CAR-T combination therapy offers new directions for improving cancer treatment compared to targeted therapy alone. In this article, we review the major challenges of CAR-T therapy in solid tumors in recent years and the current research progress of commonly used CAR-T combination therapy strategies, in order to explore the potential items for improving the efficacy of CAR-T therapy in the future.
Chinese Hamster Ovary (CHO) cells are the most commonly used cells for producing therapeutic recombinant proteins. At present, random integration (RI) is still the main strategy for the construction of recombinant CHO cell lines. Due to the lack of genomic stability in CHO cells, 1-2 rounds of high-throughput screening are usually required to obtain cell lines with high yield, good quality and suitable for a specific process,which is a process with heavy workload, time-consuming and poor batch stability. Site-specific integration (SSI) is a gene editing technique that integrates foreign genes into specific sites to obtain stable, high-yield cell lines adapted to specific production process through one round of screening, thus shortening the construction cycle of cell lines. In recent years, there have been continuous reports of cases where the site-specific integration strategy was applied to construct recombinant CHO cell lines. The most commonly used techniques are nuclease, transposon, and recombinase techniques. The recombinase with great commercial prospect and its application in CHO cell line construction are discussed after considering the construction process, efficiency and patents.
Tissue defects caused by trauma, tumors and congenital developmental abnormalities seriously affect the physiological function and mental health of patients. Processes of tissue regeneration and repair are complex. The body’s ability to regenerate and repair tissue defects gradually weakens, which is mainly based on scar repair with fibrous capsule. Laponite (LAP) has been widely used for functionalized modification of tissue regeneration biomaterials due to its unique nano-layered structure and surface electrochemical characteristics, which can interact with a variety of biomolecules and drugs and exhibit better cytocompatibility and bioactivity. The properties and characteristics of LAP and its application in the field of tissue regeneration and repair are reviewed in order to promote better clinical translation of LAP research outcomes.
With the growth of the nucleic acid testing market, conventional nucleic acid detection approaches such as gel electrophoresis and quantitative real-time PCR (qPCR) have gradually failed to meet the needs of clinical analysis, inspection and quarantine due to their limitations (cumbersome operation, expensive equipment, long reaction time and so on). Nucleic acid detection strip (NADS), a new nucleic acid detection approach with the advantages of high sensitivity, convenient operation, visualization of results, low cost and short time consuming, has attracted extensive attention in basic research and clinical diagnosis. The new progress of NADS in the past ten years was systematically introduced. Meanwhile, the principle, advantages and clinical potential translation value of NADS were summarized in order to provide reference for the further development and utilization of nucleic acid detection strip.
Coumarins are important compounds in nature. They show a wide range of applications, due to their multiple bio-activities such as antitumor, anticoagulation, antibacterial, and insecticidal. At present, most of these compounds are obtained through plant extraction, which is greatly affected by environmental factors, resulting in low yield and high cost, and therefore is not conducive to large-scale production and hinders their application. Instead, the biosynthesis process is controllable. It becomes a research hotspot to develop industrialized production technology of target natural products through optimization of the biosynthetic expression elements, host and fermentation conditions. However, mining of key enzymes in the biosynthetic pathway is still a difficult task in this research field. In this paper, the structure, function and biosynthesis of some coumarins and their derivatives are reviewed, which provides a reference for gene mining and heterologous expression of the synthetic pathways of these compounds.
Yarrowia lipolytica has great application potential in the field of microbial fermentation of chemicals due to its clear genetic background, relatively mature molecular manipulation system, strong stress resistance, broad substrate spectrum, and strong organic acid and protein secretion capabilities. Lignocellulose is the most abundant renewable biomass resource on the earth, and the use of lignocellulose materials to replace fossil materials to produce chemicals is of great significance in alleviating global energy crisis and ensuring food security. Y. lipolytica can naturally metabolize glucose produced by hydrolysis of lignocellulose. However, the utilization efficiency of other hydrolysis products such as xylose is extremely low. This article reviews the metabolic pathways and engineering strategies of Y. lipolytica using lignocellulosic materials, as well as examples of using lignocellulosic materials to produce chemicals, and focuses on the bottlenecks in this process. The solutions to these bottlenecks were also discussed, with the aim to provide useful information for relevant studies in this field.
In nature, chitin is the second largest class of polymers after cellulose. Chitin is formed by the polymerization of N-acetyl-D-glucosamine. The conversion of this abundant and cheap biomass feedstock into functional substances or energy by biorefineries is significant in terms of economic efficiency and environmental protection. There is a wealth of sources of microbial chitinase, which is the main medium for biodegradation or utilization of chitin. Since the low yield and ineffective activity of chitinase in wild-type strains limit the efficiency of the utilization of chitinous resources, recent studies on chitinase have focused on the enhancement of yield and catalytic activity. In addition, chitinases have the application value of hydrolyzing the cell wall of pathogenic fungi, destroying the body wall of pests, and producing N-acetylglucosamine oligomers or monomers, which show great market potential in the fields of medicine, agriculture, and food processing. This paper systematically summarizes the sources, classification and recent advances in engineering of microbial chitinases, as well as their wide applications in biotechnology and provides an outlook on the future development and utilization of chitinases.
Deep eutectic solvent is a new type of green solvent, which is composed of hydrogen bond acceptor and hydrogen bond donor with a certain stoichiometric ratio. It has low preparation cost and is friendly to the environment. It can be used as an alternative solvent for ordinary organic solvents and ionic liquids.As a biocatalyst, enzyme has mild reaction conditions, high substrate specificity, and high catalytic efficiency and reaction speed. Enzymatic reaction usually occurs in aqueous solution, but recently it has been found that it can also be carried out effectively in deep eutectic solvents. In order to better understand the effects of deep eutectic solvents on enzyme, the mechanism of the interaction between enzyme and deep eutectic solvents and the latest progress in application are systematically discussed. At the same time, the advantages and disadvantages of deep eutectic solvents in enzymatic reaction are evaluated. Finally, the future development prospects are discussed.
Synthetic biology is an interdisciplinary subject with the characteristics of materials science, medicine and informatics. It has been endowed with a special and important position in the view of overall national security concept while promoting the medical progress and development of science and technology. How to deal with the challenges in the new era is an important proposition in terms of scientific and technological governance and biosafety for all of the countries in the world and internation society. This article mainly introduces the threat of biological weapons, bioterrorism threat, regulations of the International Convention on Biosafety and the ethical governance framework of biosafety related to synthetic biotechnology, summarizes the risks of biosafety related issues in the field of synthetic biotechnology in recent years, and puts forward suggestions for the strategies and the development of science and technology in the view of overall national security concept.
