Objective: To study the role of protein arginine methyltransferase 5 (Prmt5) in cerebral vascular development and homeostasis maintenance in mice, and to investigate the effect of Prmt5 specific knockout on the central nervous system. Methods: We crossed Prmt5fl/fl mice with SP-A Cre transgenic mice that express Cre recombinase in cerebrovascular endothelial to generate cerebrovascular endothelial cell-specific Prmt5 knockout mice. H-E staining and immunostaining were performed to observe the vascular structures of control and Prmt5fl/fl mutant mice. Laser speckle contrast imaging was used to detect cerebral blood flow in control and mutant mice. Sulfo-NHS-Biotin was intraperitoneally injected into control and mutant mice to examine the blood brain barrier(BBB) integrity. The expression levels of astrocyte glial fibrillary acidic protein (GFAP), S100 calcium-binding protein β (S100β), complement C3 (C3), C1q, tumor necrosis factor alpha(TNF-α) and Interleukin-1 beta(IL-1β) were detected by immunofluorescence and Western blot to evaluate the activation level of astrocytes in cortex, thalamus and cerebellum of knockout mice and control mice. Furthermore, activators of astrocytes, such as C1q, TNF-α, IL-1β and other cytokines, were also detected by real-time PCR. Results: We found that cerebrovascular endothelial cell-specific Prmt5 knockout mice exhibited aberrant cerebrovascular structure, and increased the number of reactive astrocytes. The expression levels of TNF-α and IL-1β in the whole brain, as well as the C1q, TNF-α and IL-1β, were all increased in Prmt5fl/fl mutant mice. Conclusion: Prmt5 plays an essential role in the maintenance of cerebrovascular homeostasis, suggesting that it might act as a potential therapeutic target for cerebrovascular diseases.
Objective: To study the effect of ubiquitin-specific protease 13 (Usp13) on the apoptosis of mouse hepatocytes stimulated by palmitic acid,and to explore the underlying molecular mechanism. Methods: Mouse primary hepatocytes were isolated by two-step collagenase perfusion technique,and then stimulated with palmitic acid after cultured in vitro.Lipid accumulation was detected by triglyceride quantitative method and oil red O staining. Cell viability was measured by MTS and LDH assay. The apoptosis of hepatocytes was tested by Annexin V-FITC/7-AAD assay. Finally the expression levels of anti-apoptotic genes and pro-apoptotic genes were detected by qPCR and the activation of Caspase-3 was detected by Western blotting. Results: Knockdown of Usp13 did not affect the accumulation of triglyceride in palmitic acid-induced hepatocytes,but the cell viability was decreased and apoptosis was increased.Studies show that knockdown of Usp13 resulted in the down-regulated expression of anti-apoptotic genes Bcl-2 and Bcl-xl, and the up-regulated expression of pro-apoptotic genes Bid and p53.The Caspase-3 activity in Usp13 knockdown hepatocytes was enhanced after being exposed to palmitic acid. Conclusion: This study revealed the mechanism of Usp13 regulating the apoptosis of hepatocytes induced by palmitic acid, which laid a foundation for further study of Usp13 regulating the occurrence and development of non-alcoholic steatohepatitis.
In the field of equine immunology, research on equine B lymphocytes has been greatly hampered by the lack of commercial monoclonal antibodies of IgG. IgG is an important component of B cell receptor (BCR), which is associated with the differentiation and maturation of B cells. In order to obtain specific monoclonal antibodies of equine IgG, single B lymphocyte amplification was used to screen the antibodies. Firstly, the codon of equine IgG protein (EqIgG1-C) was optimized and synthesized on eukaryotic expression vector pcDNA3.4, and the antigenic protein was purified. Subsequently, the mice were immunized with the protein, and after the spleen cells were separated, the specific single B lymphocyte was separated by flow cytometry. The variable region genes of heavy and light chain of antibody were amplified by overlapping PCR method, and the complete antibody was identified. Finally, 27 strains of specific recombinant monoclonal antibodies were obtained from 80 B cells, and 3 strains with the strongest linear binding activity were selected and constructed into expression vector. After co-transfection of Expi293FTM cells, antibodies were expressed and purified. Verified by ELISA and Western blot, the results showed that the antibodies has extraordinary binding activity to EqIgG1-C protein. Using this method can save time and obtain specific antibodies efficiently, which provides an important research tool for the study of equine immunology.
Enhancers are essential cis-regulatory DNA elements, which are involved in many biological processes and closely associated with the initiation and progression of cancer and various human diseases. Although bioinformatics-based methods can identify and screen enhancers, the uncertainty in the orientation and distance between enhancers and target genes makes it difficult to study the functional mechanism of enhancers in-depth. Recently, the continuous development and innovation of CRISPR/Cas technology makes it applicable to the investigation and validation on the molecular mechanisms of enhancers. This article reviews the progression of CRISPR/Cas technology and its application in biology and focuses on the innovative applications of CRISPR/Cas technology in enhancer research in recent years (e.g., how CRISPR/Cas technology edits enhancers and the principles of different CRISPR/Cas technologies), aiming to provide a feasible reference for further study on the enhancer functional analysis.
As one of the three major elements in tissue engineering research, tissue engineering scaffolds provide an excellent environment for cell attachment, migration and proliferation. Traditional preparation techniques of polymeric scaffolds for tissue engineering, such as particle leaching, phase inversion and electrospinning, are relatively mature in theory and technology, but since most of them require the participation of organic solvents, there are still problems in the process, like the residual organic solvents, the control of holes and the poor connectivity. Supercritical carbon dioxide (SC-CO2) has a density similar to that of a liquid, while its viscosity and diffusion coefficient is closer to that of a gas, respectively, and it possesses a special performance of physical and chemical properties like strong fluidity, large dissolving power, and high heat transfer efficiency. Combining with traditional technology, it can effectively circumvent the problems mentioned above in a green and gentle system, which has broad prospects in the scaffolds preparation of tissue engineering and drug loading.
In recent years, with the continuous breakthrough of computer hardware capability, software efficiency and data abundance, the applications of artificial intelligence technology represented by machine learning have been continuously expanded and integrated, which has greatly promoted the development in fields of biology, medicine, pharmacy, and especially drug R&D. Among those technology advancements, the identification of drug-target interactions (DTI) is an important problem in the field of drug R&D and a popular research direction for the cross-integration of artificial intelligence technology. As the source of innovative drug development, drug-target interaction prediction can provide high-probability potential drug targets for biological experiments, thereby increasing the rate of lead compound discovery, increasing the success rate of late-stage drug development and shortening the total development cycle. Researchers have already done a lot of work in constructing the prediction methods of drug-target interactions by building databases, developing software and establishing machine learning algorithms. In most works, data are transformed into feature vectors or similarities, and then suitable machine learning methods are employed to build predictive models. This paper introduces the basic process and reviews the research progress of drug-target interaction prediction based on machine learning. In addition, the advantages and disadvantages of existing prediction methods are briefly summarized in order to facilitate the development of more efficient prediction algorithms and drug-target interaction prediction methods.
Extending the span of a healthy lifespan is of great significance to everyone. Centenarians have unique characteristics of the intestinal microbiome. The gut microbiome lies at the core of many age-associated changes, and the changes in microbial characteristics and genetic composition can affect longevity. Some diets and drugs cannot play a life-extension effect without the participation of microorganisms, which play an important mediating and transforming role. Probiotics and fecal transplantation and other measures have been confirmed to affect the body’s lifespan in animal models. More and more studies have shown that microorganisms could produce small molecular compounds to promote healthy aging and even prolong individual life spans, such as γ -aminobutyric acid and capsular iso-polysaccharide acid. They also affect host biosynthesis metabolism, such as 5-hydroxytryptamine, and even indirectly participate in the regulation of host signal pathways. At present, there is no systematic summary of the biological functions of these microorganisms and their effects on the host lifespan. The article reviews the evidence and physiological mechanism of intestinal microorganisms’ effects on lifespan, providing a reference for interventions to improve health status in the elderly.
Interleukin-6 (IL-6) is a pleiotropic cytokine, which participates in many physiological and pathological functions. Studies have shown that IL-6 first forms a heterohexameric complex with its own receptors (IL-6R, gp130), which further activate downstream signal transduction pathways, and finally exerts biological functions. However, abnormal activation and dysfunction of IL-6 signaling pathway are closely related to a variety of diseases, such as autoimmune diseases, chronic inflammation, and malignant tumors. In addition, the abnormal expression of IL-6 also plays an important role in COVID-19’s cytokine storm syndrome (CSS). In general, treatments that block key molecules in the IL-6 signaling pathway can be used for IL-6-related diseases. Different from blocking shared receptor molecules such as IL-6R or gp130, therapeutic monoclonal antibodies that block IL-6 protein are more specific. In clinical research, some antibodies targeting IL-6 show their unique therapeutic characteristics and beneficial effects. At present, only one monoclonal antibody drug targeting IL-6 protein has been approved by the US FDA for marketing, and more than 8 therapeutic monoclonal antibodies are in the clinical research. This article focuses on a brief review of therapeutic monoclonal antibodies targeting human IL-6 protein around world and their clinical applications.
microRNAs(miRNAs)are highly conserved non-coding small RNA in eukaryotes. They have many biological functions and can participate in the regulation of disease, cell proliferation and differentiation and other biological process. miR-138 as a tumor suppressor has been widely studied in tumorigenesis and therapy and also plays a regulatory role in cardiovascular and neurological disorder processes, osteogenic differentiation, adipogenesis and ovarian function maintenance. In this paper, prospects for future research direction of miR-138 are analyzed and discussed on the basis of summarizing and analyzing the latest research progress of miR-138 related functions, aiming to provide reference and theoretical basis for exploring miR-138 biological functions in the future.
Three-dimensional genomics is a newly developed subject that studies the three-dimensional space and structure of genome. Based on considering genome sequence, gene structure and its regulatory elements, it studies the functions of gene replication, transcription, repair and regulation in biological processes and the three-dimensional structure of genome sequence in the nucleus. With the emergence and improvement of high-throughput sequencing technology, the research of three-dimensional genomics has developed rapidly. This paper focuses on the development process, research technology and structural level of three-dimensional genomics, and summarizes the application of three-dimensional genomics in animal genetics and breeding in recent years.
Wound induced dedifferentiation(WIND) is one of the members of the APETALA2/ETHYLENE RESPONSE FACTOR (AP2/ERF), a large transcription factor gene family, which exists in all plants. Currently, most of the researches of WIND transcription factor focus on the Arabidopsis thaliana, but there are few studies on other plants. As a summary of the researches in recent years on the roles of WIND gene in plant wound signal response, the formation of callus, plant growth and metabolism, and epigenetic regulation, the present review is expected to provide a theoretical basis for further research on the function and application of WIND gene.
Bacteria need to absorb a variety of nutrients from the outer environments for their survival and replication. The small molecules less than 600 Da can freely pass the outer membrane of the gram-negative bacteria. However, for the transportation of the large size of nutrients, the TonB-dependent receptors of gram-negative bacteria are required. TonB-dependent receptors have been found to be present in all the sequenced gram-negative bacteria, but the number of TonB dependent receptors and their functions are various in different bacteria. It has been shown that TonB-dependent receptors were not only involved in the transportation of many different nutrients, such as iron, heme, manganese, zinc, vitamin, and carbohydrate, but also the secretion of protease. This review provided detailed information about the functions and structure of TonB-dependent receptors from different gram-negative bacteria. It will be helpful for the further understanding of the new functions of TonB-dependent receptors.
The oligosaccharides are low-molecular-weights molecules degraded from polysaccharides. They possessed versatile physiological activities such as antioxidant, antitumor, antivirus and immune regulatory activities and have become the focus of functional food researches. Recently, the separation and preparation of oligosaccharides mainly used ion exchange chromatography, gel permeation chromatography and their union methods. However, these methods have disadvantages such as long separation time, high preparation costs and difficulty for large scale applications. The membrane separation technology can realize the separation of bi-components or multi-components based on the selective permeation process. It possessed several advantages such as easy operation, good separation effects, high efficiency and low energy consuming. Especially, it could be directly converted into large scale industrial applications and therefore it holds great potential for separation and preparation of oligosaccharides. The review systematically summarized the recent advances on the classification, separation operations and applications of membrane separation technology in oligosaccharides separation. In addition, it also discussed the challenges of membrane separation technology in applications of oligosaccharides separation processes.
Since the 20th century, the field of stem cells and regenerative medicine has always been one of the hot frontiers in the international biomedical field. It plays an irreplaceable role in safeguarding human life and health, improving the quality of human life, and extending human life. Therefore, major technological countries such as the United States, European countries, Japan, and China have included the field in their national strategies for scientific research and industrial development, and have encouraged innovation and development in this field through special support, policy subsidies, and legislative guarantees. This article analyzes the international technology development strategy and research and development trends of stem cells and regenerative medicine in recent years, discovers the international strategic layout rules, reveals leading strengths and weaknesses of China, and try to provide relevant references for the development of China in the field.
