Effect of Ebosin on the inflammatory cytokines in THP-1 cells / 药学学报

Ebosin is a novel exopolysaccharide produced by Streptomyces sp.139 with remarkable activity against rheumatic arthritis in vivo. In this paper, we reported effects of Ebosin on the inflammatory cytokines including interleukin-1beta (IL-1beta), interleukin-6 (IL-6) and tumor necrosis factor alpha (TNFalpha) in THP-1 cells. With the special fluorogenic peptide as substrates, the enzymatic activities of interleukin-1beta converting enzyme (ICE) and TNFalpha-converting enzyme (TACE) were inhibited by Ebosin separately. Using the real-time reverse transcription polymerase chain reaction (real-time PCR), the mRNA synthesis of the three cytokines were identified decline separately by Ebosin. The secretion quantum of three cytokines in THP-1 cells with Ebosin was lower than that of normal THP-1 cells determined by ELISA assay and Western blotting. All of these results showed that Ebosin has remarkably suppressed synthesis of the three cytokines in THP-1 cells through different pathways. The primary study of Ebosin on anti-inflammation mechanism was promoted developing the new drugs treating rheumatic arthritis.

Ultrastructure and compression elasticity of sarcomere in different activated states using atomic force microscopy / 医用生物力学

Objective To construct a system for studying the ultrastructure and mechanical properties of insect flight muscle fiber in different activated states so as to carry out cardiac biomechanics study in physiological environment, and further promote understanding of the relationship between cardiac structure, mechanical properties and physiological function, and provide more clues for the basic and clinical research on cardiac diseases. Methods The ultrastructure of insect flight muscle fibrils in rigor, relaxed and activated state was investigated using the tapping mode of atomic force microscopy (AFM), and the elasticity of muscle fibers in different physiological states was studied using the nanoindentation. Results Sarcomere lengths of insect flight muscle fiber in rigor, relaxed and activated state were (2.10±0.05), (3.10±0.10), (2.50±0.15) μm (2 mmol/L Ca2+), (2.60±0.25) μm (5 mmol/L Ca2+) and (2.55±0.15) μm (10 mmol/L Ca2+), respectively, while the A-band length maintained at 1.50 μm and I-band changed from 0.7~1.6 μm. Mechanical test found that the elasticity of different bands or lines in the same physiological state varied in the order of Z-line>M-line>overlap>I-band. Conclusions Critical Ca2+ concentration for muscle fiber activation was 5 mmol/L, and sarcomere length distributions were in line with the relative slip theory and structure model, and AFM was the potential tool for the high resolution study on ultrastructure and mechanical properties of the muscle fibers.

Application of atomic force microscopy in ultrastructure and biomechanics of cells and biomacromolecules / 医用生物力学

To be the representative fruition resulted from the rapid development in micro-nano theory and technology, atomic force microscopy (AFM) has greatly promoted the expansion of biological research in micro-nano scale, and facilitated the birth and development of micro-nano biology as an important technique in its 25-year evolutional progress. Based on the fundamental principles and detection modes of AFM, as well as the author’s research findings and work experience in this field, the paper reviews the application of AFM in the study on ultrastructure and biomechanical properties of cells and biomacromolecules in the aspects of biological structure and morphology, surface physicochemical characterization and mechanical manipulation of biological macromolecules, and focus on some important scientific and technical problems on AFM in micro-nano biomedical research needed to be improved and solved urgently, with exploratory insights and recommendations for potential users in ultrastructure and biomechanics of cells and biomacromolecules.

Study of a novel compound 2460A with activities produced by fungus / 药学学报

With IL-6R as target, a new compound 2460A was identified from fungus using HTS screening model. The taxonomics of the produced strain was confirmed to be Trichoderma hazianum rifai after sequencing analysis of rDNA-ITS (internal transcribed spacer). Results showed that this compound has a binding activity on IL-6R competed with IL-6, thus it is a new ligand of IL-6R originating from microbe. With MTT assay, the anti-tumor activities of 2460A were demonstrated on CM126 and HT-29 cell lines separately, the IC50 are 2.17 x 10(-5) mol x L(-1) and 1.8 x 10(-5) mol x L(-1) respectively. The compound affected lightly the HT-29 cell cycle at S phase. Studies for the anti-tumor activity of 2460A in vivo are in progress in our lab.

Purification and Characterization of ?-AE Protein Expressed in E.coli / 中国生物工程杂志

Many bioactive peptides from neural and endocrine tissue are amidated at C-terminals,which is essential for their activities.The ?-amide comes from post-translational modification that is catalyzed by ?-AE (?-amidating enzyme) or PAM (pepdilylglycine ?-amidating monooxygenase).The gene encoding ?-AE was amplified with PCR and cloned into the plasmid pET-30a.After the recombinant plasmid pET-A was transformed into E.coli BL21,the ?-AE was expressed and purified by the Ni2+affinity chromatography,which has the ability catalyzing Dns-Tyr-Val-Gly to Dns-Tyr-Val-NH2.It identified that the recombinant protein producing by E.coli BL21 is ?-AE,which will benefit for studies of amidation at the C-terminals of peptides.