Effect of Artesunate on Experimental Choroidal Neovascularization and Expression of HIF-1α and VEGF / 中国实验方剂学杂志

Objective:To observe the effects of artesunate （ART） on experimental choroidal neovascularization （CNV） and the expression of related proteins， and to explore the underlying mechanism. Method:Eighty BN rats were randomly divided into five groups： a normal group， a model group， a conbercept group， and low- （10.08 mg·kg^-1·d^-1） and high-dose （20.16 mg·kg^-1·d^-1） ART groups， with 16 rats in each group. A CNV model was established with 532 nm laser in rats of the groups except for the normal group. The rats in each group were treated with corresponding drugs by gavage for 14 days. The normal group， the model group， and the conbercept group received 1% CMC-Na solution at the same volume， while the conbercept group received an intravitreal injection （5 μL） once. On days 7 and 14， fundus fluorescein angiography （FFA） was used to evaluate the fluorescein leakage （gray value） of CNV. Hematoxylin-eosin （HE） staining was adopted to observe the histopathological changes of CNV. Western blot was employed to detect the protein expression levels of hypoxia-inducible factor-1<italic>α</italic> （HIF-1<italic>α</italic>） and vascular endothelial growth factor （VEGF） in the retina and choroid. Result:FFA results showed that compared with the normal group， other groups showed increased gray value on days 7 and 14 （<italic>P</italic><0.01）. On day 7， the gray value of the high-dose ART group and the conbercept group decreased compared with that in the model group （<italic>P</italic><0.01）. On day 14， the gray value of the ART groups and the conbercept group decreased in varying degrees compared with that in the model group （<italic>P</italic><0.05， <italic>P</italic><0.01）. HE results showed that compared with the normal group， the model group showed increased thickness of CNV on days 7 and 14 （<italic>P</italic><0.01）. Compared with the model group， the ART groups and the conbercept group displayed decreased thickness of CNV （<italic>P</italic><0.01）. Western blot results revealed that the expression of HIF-1<italic>α</italic> and VEGF in the model group increased in varying degrees on the days 7 and 14 compared with that in the normal group （<italic>P</italic><0.05， <italic>P</italic><0.01）， while compared with the model group， the ART groups and the conbercept group showed decreased expression （<italic>P</italic><0.01）. Conclusion:ART can inhibit experimental CNV by down-regulating the expression of HIF-1<italic>α</italic> and VEGF in the early stage of experimental CNV formation.

Advances in animal models of retinal vein occlusion induced by laser photocoagulation and photodynamic therapy / 中华实验眼科杂志

Retinal vein occlusion (RVO) is a common retinal vascular disease that causes vision loss.The etiology of RVO is complex and its pathogenesis has not yet been fully elucidated.With the development of modern medical technology, there are more and more methods to induce animal models of RVO.Laser photocoagulation and photodynamic therapy (PDT) are the main induction methods for animal models of RVO.Up to now, animal models of RVO have been successfully induced by laser photocoagulation or PDT in many animal species (e.g., mouse, rabbit, pig and monkey). The fundus of different animals can exhibit clinical characterization and histopathological features that approximate those typical of human RVO.In addition, animal model of RVO induced by laser photocoagulation or PDT still lacks standard experimental parameters and has its own advantages and limitations.Therefore, methods of establishing an ideal animal model of RVO on the basis of previous experience, importance for the study of the etiology, pathology and drug intervention of human RVO are reviewed in this article.

The construction of a novel recombinant virus Δ67R-RGV and preliminary analyses the function of the 67R gene / 病毒学报

The Rana grylio virus (RGV) is a member of the genus Ranavirus. It belongs to the family Iridoviridae, and contains the gene 67R encoding dUTPase. In order to investigate the function of 67R in the replication and infection of RGV, we constructed Δ67R-RGV, a recombinant virus with deletion of 67R. First, we constructed the plasmid pGL3-67RL-p50-EGFP-67RR which carried an enhanced green fluorescence gene (EGFP) as a selectable marker. After homologous recombination between pGL3-67RL-p50-EG- FP-67RR and the RGV genome, Epithelioma papulosum cyprini (EPC) cells were infected with the resulting mixture. Through ten successive rounds of plaque isolation via EGFP selection, all plaques emitted green fluorescence, and finally Δ67R-RGV was generated. Total DNA of Δ67R-RGV infected cells was extracted for PCR analyses. Simulateously, mock infected and wild-type RGV (wt-RGV) infected cells were used as a comparison. Results showed that 67R could be detected in wt-RGV infected cells, but that only the EGFP gene was detected in Δ67R-RGV infected cells. Furthermore, one-step growth curves of wt-RGV and Δ67R-RGV were similar. Therefore, 67R and its encoding product dUTPase might not be essential for the growth of RGV. These results suggest that, homologous recombination and recombinant rana- virus could be used to study the gene function of viruses in aquatic animals.

Method for Japanese encephalitis virus NS3 protease activity analysis and high-throughput screening assay for inhibitors / 生物工程学报

Japanese encephalitis virus (JEV) is a single-stranded and positive-sense RNA, which has a single ORF (open reading frame), encoding a polyprotein precursor. Non-structural protein 3 (NS3) plays an important role in processing the polyprotein precursor and has become an important drug target of flavivirus. In this study, NS2BH-NS3 gene was amplified by PCR and subcloned to the prokaryotic expression plasmid, resulting pET30a-NS2BH-NS3. The fusion protein was expressed in Escherichia coli BL21 (DE3) in soluble form after induction by Isopropyl beta-D-1-Thiogalactopyranoside (IPTG). The recombinant protein was purified by Ni-NTA affinity column. Then a fluorescence resonance energy transfer (FRET) method was used to determine enzymatic activity and the assay conditions were optimized. After screening 113 compounds, we found two compounds inhibiting the activity of NS2BH-NS3. This study provides a convenient and cost-effective method for screening of JEV NS3 protease inhibitor.