1.Effect of quercetin on rat cardiomyocyte apoptosis induced by adriamycin in vitro
Tianxian PEI ; Changqing XU ; Jing YU ; Hongzhu LI ; Jin GUO ; Xiuxiang GAO ; Weiming ZHAO ; Baofeng YANG
Chinese Pharmacological Bulletin 1986;0(04):-
Aim To observe the protective effect of quercetin on rat cardiomyocyte apoptosis induced by adriamycin and explore its possible mechanism.Methods Cultured neonatal rat cardiomyocytes were randomly divided into six groups:normal control group, adriamycin group,quercetin control group, adriamycin+quercetin(25,50,100 ?mol?L-1)groups. The activity of LDH was detected by chromatometry, the cardiomyocyte viability was measured by MTT, the ultrastructure of cardiomyocyte was observed by electron microscope, the expression of protein Bcl-2 and Bax was analyzed by immunocytochemical, and the mRNA and protein of caspase-3 were detected by RT-PCR and Western blot respectively.Results Compared with the control group, the activity of LDH was increased but the viability of cardiomyocyte was decreased; the expression of Bax and caspase-3 was up-regulated while Bcl-2 was down-regulated in ADR group.Compared with ADR group, the above changes were lightened in adriamycin+quercetin groups. But the quercetin control group, in which cultured myocardial cells only exposed to quercetin without ADR, had no obvious changes.Conclusions Quercetin significantly inhibits the apoptosis induced by ADR in the cultured myocardial cells. Its mechanism is involved in the apoptosis-related pathways, including caspase-3, Bax and Bcl-2.
2.Production of CCHF Virus-Like Particle by a Baculovirus-Insect Cell Expression System
Zhaorui ZHOU ; Manli WANG ; Fei DENG ; Tianxian LI ; Zhihong HU ; Huafin WANG
Virologica Sinica 2011;26(5):338-346
Crimean-Congo Haemorrhagic Fever Virus(CCHFV)is a tick-born virus of the Nairovirus genus within the Bunyaviridae family,which is widespread and causes,high fatality. The nucleocapsid of CCHFV is comprised of N proteins that are encoded by the S segment. In this research,the N protein of CCHFV was expressed in insect cells using a recombinant baculovirus. Under an electron microscope,Virus-Like Particles (VLPs)with various size and morphology were observed in cytoplasmic vesicles in the infected cells.Sucrose-gradient purification of the cell lysate indicated that the VLPs were mainly located in the upper fraction after ultracentrifugation,which was confirmed by Western blot analysis and immuno-electron microscopy(IEM).
3.Genetic Characteristics of 2009 Pandemic H1N1 Influenza A Viruses Isolated from Mainland China
Jiuru ZHAO ; Yongdong LI ; Limin PAN ; Na ZHU ; Hongxia NI ; Guozhang XU ; Yongzhong JIANG ; Xixiang HUO ; Junqiang XU ; Han XIA ; Na HAN ; Shuang TANG ; Zhong ZHANG ; Zheng KOU ; Simon RAYNER ; Tianxian LI
Virologica Sinica 2011;(6):418-427
A total of 100 HIN1 flu real-time-PCR positive throat swabs collected from fever patients in Zhejiang,Hubei and Guangdong between June and November 2009,were provided by local CDC laboratories.After MDCK cell culture,57 Influenza A Pandemic (H1N1) viruses were isolated and submitted for whole genome sequencing.A total of 39 HA sequences,52 NA sequences,36 PB2 sequences,31 PB1 sequences,40 PA sequences,48 NP sequences,51 MP sequences and 36 NS sequences were obtained,including 20 whole genome sequences.Sequence comparison revealed they shared a high degree of homology (96%~99%) with known epidemic strains (A/Califomia/04/2009(H1N1).Phylogenetic analysis showed that although the sequences were highly conserved,they clustered into a small number of groups with only a few distinct strains.Site analysis revealed three substitutions at loop 220 (221-228) of the HA receptor binding site in the 39 HA sequences:A/Hubei/86/2009 PKVRDQEG→PKVRDQEA,A/Zhejiang/08/2009 PKVRDQEG→PKVRDQER,A/Hubei/75/2009PKVRDQEG→PKVRDQGG,the A/Hubei/75/2009 was isolated from an acute case,while the other two were from patients with mild symptoms.Other key sites such as 119,274,292 and 294 amino acids of NA protein,627 of PB2 protein were conserved.Meanwhile,all the M2 protein sequences possessed the Ser32Asn mutation,suggesting that these viruses were resistant to adamantanes.Comparison of these sequences with other H1N1 viruses collected from the NCBI database provides insight into H1N1 transmission and circulation patterns.