6-desulfated heparin inhibits heparan sulfate shedding and epithelial cell damage during bleomycin induced pulmonary injury / 中国药理学通报

Aim To study the effect of different hepa- ry.Methods First, heparin derivatives with different rin sulfation patterns on bleomycin induced lung inju- sulfation patterns,6-desulfated heparin (6-DeH) and N-acetvlated heparin ( N-AcH ) , were synthesized.Secondly, the effect of these compounds on BLM-in¬duced bronchial epithelial cell ( BEARS-2B) injury was evaluated via lactate dehydrogenase activity, MTT experiment, Annexin V/ PI staining and Hoechst 33258 staining.Then , immunofluorescence staining and West¬ern blotting were used to investigate the shedding of Svndecan-1 and the activation of c-Met by 6-DeH/Akt j j signaling pathway.Finally, a BLM-induced lung injury mouse model was used to further verify the protective effect of 6-DeH by HE staining, Svndecan-1 immunos- taining,bodv weight change,and survival rate.Results In the BLM-induced BEARS-2B injury model, 6- DeH was selected as the best candidate, which exerted their effect by competitively binding to BLM, thereby reducing the damage of heparan sulfate barrier (Svnde- can-1 ) on cell surface, and improving cell survival by activating the downstream c-Met/Akt pathway.In the BLM-induced lung injury mouse model, it was further confirmed that 6-DeH reduced the shedding of Svnde- can-1 in the early stage, and delayed the lung injury and fibrosis process.Conclusions 6-DeH protects the bronchial epithelial cells against BLM-induced lung in¬jur)' through inhibiting the shedding of Svndecan-1 and activating the c-Met/Akt signaling pathway.

Functional discovery and production technology for natural bioactive peptides / 生物工程学报

Bioactive peptides play important roles in promoting human health, such as lowering blood pressure, blood sugar and blood lipid, anti-obesity, and anti-cancer. Thus, exploring functional bioactive peptides and developing efficient production technologies are of crucial importance. Herein, we review the development of function discovery and production technology for natural bioactive peptides. Presently, the top-down and bottom-up approaches are mainly used for the function discovery and production of natural active peptides. The top-down approach includes the direct extraction and identification for functional discovery, and the direct extraction, enzymatic hydrolysis and microbial fermentation for production. The bottom-up approach includes the polypeptide modification and database mining for functional discovery, and the chemical synthesis, enzyme synthesis, recombinant expression and cell-free synthesis for production. The top-down approach is usually associated with complicated process, lower efficiency, higher cost, harder quality control, and uncertain functionality, while the bottom-up approach is more suitable for the development of peptide drugs but difficult to be used for functional foods. With the technology development of sequencing and mass spectrometry, it is easier to obtain the proteomic information of various organisms at the molecular level. Based on the proteomic information, the top-down and bottom-up approaches can be combined to overcome the disadvantages of using these two approaches alone, thus providing a new strategy for the rapid development and production of natural active peptides.

Technology development and instrumentation of a high-throughput and automated microbial microdroplet culture system for microbial evolution and screening / 生物工程学报

Since microdroplets are able to be generated rapidly in large amount and each droplet can be well controlled as an independent micro-cultivator, droplet microfluidic technology can be potentially used in the culture of microorganisms, and provide the microbial culture with high throughput manner. But its application mostly stays in the laboratory-level building and using for scientific research, and the wide use of droplet microfluidics in microbial technology has been limited by the key problems that the operation for microdroplets needs high technical requirements with wide affecting factors and the difficulties in integration of automatic microdroplet instrumentation. In this study, by realizing and integrating the complicated operations of droplet generation, cultivation, detection, splitting, fusion and sorting, we design a miniaturized, fully automated and high-throughput microbial microdroplet culture system (MMC). The MMC can be widely used in microbial growth curve test, laboratory adaptive evolution, single factor and multi-level analysis of microbial culture, metabolite detection and so on, and provide a powerful instrument platform for customized microbial evolution and screening aiming at efficient strain engineering.

Progress in the Study of Heparinases / 中国生物工程杂志

Heparinases,a kind of polysaccharide lyases,can degrade heparin and heparin sulfate to low molecular weight polysaccharides.It has been noted that many bacteria have heparinases although only few of them have been purified and characterized.Heparinases I,II and III from Flavobacterium heparinum have been extensively studied for many years and been commercialized recently.Heparinases have some important applications in the industry and clinic as well as in the determination of heparin structure,which is a very important anticoagulant drug used world-widely.The recent progresses in isolation of heparinase-producing bacteria,genome mapping of heparinase homologs in sequenced bacteria and archaea genomes,purification of heparinases and the study of their biochemistry and regulation were reviewed.The recombinant expression of these enzymes as well as important applications of heparinases and their potential applications in the future will also be highlighted.