Hypoxia promotes lipopolysaccharide-induced CXCL10 expression in microglia / 生理学报

This study was aimed to investigate the effect of hypoxia on lipopolysaccharide (LPS)-induced CXC-chemokine ligand-10 (CXCL10) expression and the underlying mechanism. C57BL/6J mice were randomly divided into control, hypoxia, LPS, and hypoxia combined with LPS groups. The LPS group was intraperitoneally injected with 0.5 mg/kg LPS, and the hypoxia group was placed in a hypobaric hypoxia chamber (simulated altitude of 6 000 m). The serum and hippocampal tissue samples were collected after 6 h of the treatment. The levels of CXCL10 in the serum and hippocampal tissue of mice were detected by ELISA. The microglia cell line BV2 and primary microglia were stimulated with hypoxia (1% O2) and/or LPS (100 ng/mL) for 6 h. The mRNA expression level of CXCL10 and its content in culture supernatant were detected by real-time quantitative PCR and ELISA, respectively. The phosphorylation levels of nuclear factor κB (NF-κB) signaling pathway-related proteins, p65 and IκBα, were detected by Western blot. Moreover, after NF-κB signaling pathway being blocked with a small molecular compound, PDTC, CXCL10 mRNA expression level was detected in the BV2 cells. The results showed that in the LPS-induced mouse inflammatory model, hypoxia treatment could promote LPS-induced up-regulation of CXCL10 in both serum and hippocampus. Compared with the cells treated with LPS alone, the expression of CXCL10 mRNA and the content of CXCL10 in the culture supernatant of BV2 cells treated with hypoxia combined with LPS were significantly increased. The CXCL10 mRNA level of primary microglial cells treated with hypoxia combined with LPS was significantly up-regulated. Compared with the cells treated with hypoxia or LPS alone, the phosphorylation levels of p65 and IκBα in the BV2 cells treated with hypoxia combined with LPS were significantly increased. PDTC blocked the induction of CXCL10 gene expression by LPS in the BV2 cells. These results suggest that hypoxia promotes LPS-induced expression of CXCL10 in both animal and cell models, and NF-κB signaling pathway plays an important role in this process.

Interplay between hepatitis B virus and the type Ⅰ interferon system and new therapeutic strategies / 复旦学报（医学版）

Hepatitis B virus (HBV) infection has been one of the most important public health problems,however,no complete cure is currently available.Although interferon (IFN)-α has been clinically used as a drug for chronic hepatitis B therapy because of its advantages including a higher rate of HBsAg/HBeAg seroconversion and a lower rate of recurrence after cessation of treatment,only 20％ -40 ％ of patients respond well to IFN therapy,thus hampering its clinical application.In recent years,based on the in vitro HBV replication and infection cell models,animal models and patient cohort with hepatitis B and by using a variety of methods,studies have been made.On the one hand,to identify new mechanisms underlying the IFN-and IFN-induced genes-mediated anti-HBV activities and signaling transduction,on the other hand,to reveal the effect and mechanisms of HBV replication and viral proteins in regulating the innate immune signaling pathways and IFN induction and antiviral action,based on which new strategies and approaches for optimization of IFN-based therapy and for a HBV cure have been further explored.This review mainly introduces the research findings of author's group and the future development is prospected.

Immobilization of catalase on Fe (III) modified collagen fiber / 生物工程学报

Fe (III) modified collagen fibers were used to immobilize catalase through the cross-linking of glutaraldehyde. The loading amount of catalase on the supporting matrix was 16.7 mg/g, and 35% enzymatic activity was remained. A series of experiments were conducted on free and immobilized catalase in order to investigate their optimal pH and temperature, and the thermal, storage and operation stability. Results suggest that the free and immobilized catalase prefer similar pH and temperature condition, which were pH 7.0 and 25 degrees C. It should be noted that the thermal stability of catalase was considerably improved after immobilization owing to the fact that the enzyme kept 30% of relative activity after incubation at 75 degrees C for 5 h. On the contrary, the free catalase was completely inactive. As for the storage stability, the immobilized catalase kept 88% of relative activity after stored at room temperature for 12 days while the free one was completely inactive under the same conditions. Moreover, the immobilized catalase preserved 57% of relative activity after being reused 26 times, exhibiting excellent operation stability. Consequently, this investigation suggests that collagen fiber can be used as excellent supporting matrix for the immobilization of catalase, and it is potential to be used for the immobilization of similar enzymes.

Selective removal of tannins from Polygonum cuspidatum extracts using collagen fiber adsorbent / 中国中药杂志

<p><b>OBJECTIVE</b>To investigate the selective removal of tannins from Polygonum cuspidatum extracts by using collagen fiber adsorbent, and to evaluate the adsorption and desorption performances of collagen fiber adsorbent to tannins.</p><p><b>METHOD</b>The adsorbent was prepared from bovine skin collagen fiber through crosslinking reaction of glutaraldehyde, and then used for the selective removal of tannins from P. cuspidatum extracts. Gelatin-turbidity method, gelatin-ultraviolet spectrometry method and HPLC were used for detection of tannins in the solutions. Ethanol-water solutions with varying concentration were used to test their desorption ability of tannins in order to choose proper desorption solution. On the basis of batch experimental results, the column adsorption and desorption tests were carried out, by using gelatin-turbidity method for detection of tannins.</p><p><b>RESULT</b>The collagen fiber adsorbent exhibited excellent adsorption selectivity to tannins. It was found that tannins of P. cuspidatum were completely removed, while nearly no adsorption of active components (resveratrol as representative) was found. Moreover, the collagen fiber adsorbent could be regenerated by using 30% ethanol-water solution and then reused.</p><p><b>CONCLUSION</b>The collagen fiber adsorbent can be considered as a promising material for selective removal of tannins from P. cuspidatum extracts.</p>

Study on Extraction Process of Polysaccharide in Ophiopogon japonicus / 中药新药与临床药理

Objective To optimize the extraction process and to establish a method for the content determination of the polysaccharides in Ophiopogonjaponicus.Methods With extracts rate of polysaccharide as the index,an orthogonal de- sign test was adopted to optimize the extraction process.And phenol-sulphuric acid colorimetric method was used to de- termine the content of polysaccharides in Ophiopogonjaponicus.Results The optimum extract conditions were as follows: refluxing twice with eight times amount of water,thirty minutes each time,and precipitation with 80 % alcohol.A good linearity of polysaccharides was in range of 0.02032～0.10008 mg(r=0.9998),and the average recovery rate was 102.41%,RSD was 1.78 %.Conclusion The polysaccharide can be fully extracted under these conditions.