The emergence and rapid development of the organoid technology has greatly improved the manufacturing ability of artificial tissues and organs, expanded the application scope of regenerative medicine, and also brought new opportunities for the development of the biomedicine industry. The analysis of the development status of the organoid technology, its application direction and industry development shows that this field is in a period of rapid growth. First, the organoid technology is in a period of explosive growth at present, the simulation level of structure and function of tissues and organs is constantly improved, and breakthroughs have been made in solving core “bottleneck” problems such as vascularization. Second, the organoids-on-a-chip technology produced by the fusion of the organoid technology and organ-on-a-chip has greatly improved the application ability of organoids. Finally, as a biological model, organoids have shown considerable application prospects in biomedical research, clinical treatment and drug research and development. Especially in drug research and development, the relevant industrial system is gradually taking shape, and the development process is advancing rapidly. In the future, with breakthoughs made in overcoming relevant technical bottlenecks and the further influx of commercial capital, the field of organoids will certainly have a broader development space, which will help the innovation and development of the biomedicine industry.
Bone diseases, such as osteoporosis and osteoarthritis, have become a serious human health hazard, making it imperative to further understand the pathogenesis of related diseases and develop more effective treatments. Due to the limitations of conventional research methods such as two-dimensional cell culture and animal experiments, the organoid technology that emerged in recent years has attracted tremendous attention. As self-organized 3D clusters derived from stem cells, organoids can recapitulate the complex structure and biological function of tissues or organs in vitro. Until now, bone organoids generated from mesenchymal stem cells, pluripotent stem cells and other cell sources have been gradually established, which not only provides an excellent platform for disease modeling, drug screening as well as fundamental research of physiology and pathology, but also raises new hope for repairing bone defects. This review summarizes the construction and main applications of various bone organoid models. The challenges faced by organoid cultivation and future development prospects are also discussed, so as to provide reference for the construction and biomedical application of bone organoids with more perfect structure and functions.
The liver is the major metabolic organ in the body and it plays a crucial regulatory role in maintaining homeostasis. In recent years, liver diseases have seriously threatened human health. However, the in vitro cultured cell lines or in vivo animal models cannot thoroughly reveal pathogenesis of human liver diseases and explore potential therapeutic targets effectively. Human liver organoids (HLOs), which are cell clusters differentiated from human cells through 3D culture in vitro, can mimic the structures and functions of the human liver in vitro. HLOs provide a new model for understanding the physiological structures and functions of the liver, simulating liver diseases in vitro, and exploring drugs for liver disease treatment. This review summarizes establishment strategies and applications of HLO models in recent years, and also discusses the defects of these models, which aim to provide a theoretical basis for the clinical applications of HLOs.
Lung is an important target organ for infection and injury by viruses, bacteria and other pathogens. In recent years, the novel coronavirus epidemic has made us realize that infectious pulmonary diseases pose a serious threat to human health, even life. Due to the urgency of the research on the pathogenesis and prevention mechanism of pulmonary diseases, lung organoids are increasingly becoming effective tools for research in this field due to their characteristics such as accurate simulation, high applicability and no ethical concerns. On the basis of tracing its development, this paper reviews the construction and application of lung organoid models in different infectious pulmonary diseases, and anticipates the future development prospects of the models.
Objective: To investigate the function and mechanism of lymphocyte activation gene 3 (LAG-3) in immune induced liver injury. Methods: Acute immune liver injury model in mice was induced by tail vein injection of concanavalin A (Con A). LAG-3 expression in hepatic immune cells was determined by flow cytometry and real-time PCR. LAG-3 knockout mice were utilized to study the effect of LAG-3 on Con A-induced immune liver injury. Peripheral blood was collected at different time points after Con A injection, and the serum levels of ALT, AST, and cytokines were detected. Liver tissue samples were collected for hematoxylin eosin staining (H & E, hematoxylin eosin staining) and the necrotic area of liver tissue was counted. Intrahepatic immune cell subsets and T cell activation were determined by flow cytometry. The expression of inflammation related genes was detected by real-time quantitative PCR. Yeast two-hybrid screening was performed to find LAG-3 interacting proteins. Results: Con A induced an increase in LAG-3 expression on hepatic immune cells; LAG-3 knockout exacerbated Con A-induced elevation of serum transaminase levels, increased necrotic area of the liver, and delayed resolution of inflammation in mice; LAG-3 knockout did not affect Con A-induced intrahepatic immune cell infiltration; LAG-3 knockout suppressed regulatory T cell expansion and IL-10 expression; MHCII accessory molecule CD74 interacted with LAG-3. Conclusions: LAG-3 knockout aggravates immune liver injury.
Cytidine is used as a raw material for drug synthesis from functional nutritional chemicals and has important application value. DNA-binding transcriptional repressors encoded by the purR gene in Escherichia coli are important regulators of cytidine anabolism. In this study, the E. coli purR gene was knocked down using CRISPR/Cas9 technology and the differences in gene expression of mutant strains were analyzed by transcriptomics. The results showed that the purR gene was successfully knocked out from the genome of the starting strain E. coli NXBG-12, and the mutant strain E. coli NXBG-17P was obtained. Comparative analysis of transcriptomic results from mutant strains E. coli NXBG-17P and E. coli NXBG-12 revealed 534 differential genes, including 302 up-regulated genes and 232 down-regulated genes. GO analysis showed that differentially expressed genes (DEGs) were mainly enriched in the metabolic processes of cytoplasmic membrane, ATP binding, DNA binding and hydrolase activity; KEGG analysis showed that up-regulated genes were mainly enriched in fructose and mannose metabolism, pyrimidine metabolism and phosphotransferase system, and down-regulated genes were mainly enriched in oxidative phosphorylation, galactose metabolism and peptidoglycan biosynthesis. Meanwhile, mutant strain E. coli NXBG-17P was fermented in a shake flask at 37℃ for 40 h. The cytidine concentration was determined to be (3.21±0.01) g/L, which was 1.58 times the level of the starting strain E. coli NXBG-12. It is well demonstrated that purR gene deletion enhances PTS (glucose phosphotransferase system) transport and pentose phosphate pathway, which can provide more NADPH and pyrimidine nucleoside precursors PRPP for cytidine synthesis pathway.
Objective: Telomere is a highly conserved structure at the end of eukaryotic chromosomes responsible for maintaining chromosomal stability, and the length of its DNA sequence, known as telomere length, gradually shortens with age or disease development. Telomere length can provide a reference for assessing the aging and health status of individuals. However, there is no satisfactory method for determining the absolute telomere length from a small amount of cattle samples. Real-time quantitative PCR (qPCR) was used to determine the absolute telomere length of minute DNA samples from cows and to assess the effect of the DNA extraction method on the results of absolute telomere length determination. This study aims to provide a reference for selecting suitable DNA extraction methods and telomere length analysis methods for a study on telomere length in cattle. Methods: The absolute values of telomere length were determined by qPCR. DNA was extracted from the same samples with silica membrane, phenol-chloroform, and magnetic beads, and the telomere lengths were analyzed by terminal restriction fragment (TRF) assay and qPCR, respectively, to compare their effect on cattle absolute telomere length determination. Results: (1) qPCR can be used to determine the absolute telomere length of nano-gram level cow DNA samples with good reproducibility and correlates well with the “gold standard” TRF results. (2) DNA extracted by different methods would result in significant differences in results when used for telomere length analysis. DNA extracted by the magnetic bead method showed the best agreement when telomere length was measured by TRF and qPCR methods. Conclusion: qPCR is a more sensitive, convenient, and rapid method for determining absolute telomere length than the TRF method and is suitable for determining minute DNA samples. The DNA extraction method can affect the results of telomere length determination and should be unified while the assay was performed, and the magnetic bead method was optimal.
CRISPR/Cas system has continuously promoted the progress in the field of life science since its discovery. At the same time, the gene editing technology mediated by CRISPR/Cas is also developing and improving continuously. The development of new gene editing tools such as CRISPR/Cas gene editing technology based on DSBs repair, base editors and prime editors has paved the way for basic biological research. Although these tools have brought revolutionary changes to biotechnology, problems such as low efficiency of gene editing, low purity of products and frequent off-target effects began to emerge. The continuous development of accurate, efficient, and secure CRISPR/Cas editing tools remains a current and future research focus. Here, the development, composition and principle of CRISPR/Cas system based gene editing tools are briefly described. The general strategies for the CRISPR/Cas system to improve editing efficiency, expand editing scope and reduce off-target effects are systematically summarized, as well as the improvement methods of different CRISPR/Cas gene editing tools. In addition, the future research direction of CRISPR gene editing tools is discussed.
Nonribosomal peptides are a class of small molecule secondary metabolites synthesized by a variety of microorganisms through nonribosomal peptide synthetase and other catalytic synthesis. With antibacterial, antitumor, immunosuppressive and other biological activities, they are an important class of microbial drugs, with high clinical application value. This paper reviews the biological functions, synthesis and assembly mechanisms of small molecule peptides, as well as the recent progress in engineering modifications, and discusses future research directions for the efficient synthesis of more types of small molecule peptides through combinatorial biosynthesis.
As important platform chemicals, medium-chain fatty acids (MCFAs) are widely used in industries such as energy, food and medicine. The production of MCFAs by industrial microbial fermentation provides a green and environmentally-friendly route, but MCFAs can cause membrane damage, cell pH and osmotic pressure imbalance and oxidative stress, resulting in inhibition of cell growth rate and production capacity. Hence, the construction of MCFA-tolerant industrial microbial strains will improve the production efficiency of MCFAs. In this paper, taking industrial microorganisms such as Escherichia coli and Saccharomyces cerevisiae as examples, the toxicity mechanism of MCFAs to microbial cells is first introduced. Second, the relevant research on using rational metabolic engineering methods such as membrane modification and transporter screening to construct MCFA-tolerant strains is reviewed. Meanwhile, the paper reviews the research progress on the use of such methods as adaptive evolution and metabolic flux analysis to systematically mine MCFA-tolerant targets and improve strain tolerance. Finally, the future research directions for improving the tolerance and production capacity of MCFAs in industrial microorganisms are discussed.
Spatial omics reveals micro-environment interactions and spatial heterogeneity between cells from a molecular perspective, which plays an important role in neuroscience, cancer research and developmental biology. The spatial omics technology has received a lot of academic attention, but it has been developing in a monopolistically competitive environment. Based on the overall situation of the global and Chinese patent applications of the spacial omics technology, this paper analyzes the trends, technical themes, application sources and main applicants of the global and Chinese patent technologies in this field, and summarizes the development status of the key technologies. At the same time, based on the above analysis, some suggestions are put forward on the technical breakthrough and development mode in the field of spatial omics.
