Neuroprotective effects of low-concentration alpha-tocopherol Confocal laser microscopy observations

BACKGROUND： Alpha-tocopherol （ α-tocopherol） can effectively relieve neuronal damage induced by oxygen-centered free radicals. However, the effective dose remains controversial. OBJECTIVE： To evaluate the protective effects of low-concentration α-tocopherol on neuronal membranes. DESIGN, TIME AND SETTING： Contrast observation and in vitro study, performed at Laboratory of Neurosurgery, Tianjin Huanhu Hospital between April and September 2006. MATERIALS： Fetal cortical neurons were derived from two 14-day pregnant SD rats, and α-tocopherol was provided by Sigma, USA. METHODS： The neurons were randomly assigned to six groups： （1） normal： neurons were cultured under normal conditions; （2） oxidative damage： oxidative free radicals was damaged using the Fenton reaction; （3） α-tocopherol： neurons were cultured in different concentrations of -tocopherol 10, 20, 40, and 80 mg/L for 2 hours, respectively. MAIN OUTCOME MEASURES： Neuronal membrane damage was observed using a confocal laser microscope, and malonaldehyde production was detected using the thiobarbituric acid method. RESULTS： At normal, biological concentrations （10 mg/L）, α-tocopherol induced no change in the damaged neurons （P 〉 0.05）. However, at a concentration of 80 mg/L, the number of damaged neurons was significantly reduced, compared with the damage group （P 〈 0.05）. Malonaldehyde levels following 80 mg/L α-tocopherol treatment were less than the oxygen free radical damage group （P 〈 0.05）, but greater than the control group （P 〈 0.01）. CONCLUSION： A concentration of 80 mg/L α-tocopherol can effectively protect the neuronal cell membrane from oxidative damage

Transcriptome profiling highlights regulated biological processes and type III interferon antiviral responses upon Crimean-Congo hemorrhagic fever virus infection

Crimean-Congo hemorrhagic fever virus(CCHFV)is a biosafety level-4(BSL-4)pathogen that causes Crimean-Congo hemorrhagic fever(CCHF)characterized by hemorrhagic manifestation,multiple organ failure and high mortality rate,posing great threat to public health.Despite the recently increasing research efforts on CCHFV,host cell responses associated with CCHFV infection remain to be further characterized.Here,to better understand the cellular response to CCHFV infection,we performed a transcriptomic analysis in human kidney HEK293 cells by high-throughput RNA sequencing(RNA-seq)technology.In total,496 differentially expressed genes(DEGs),including 361 up-regulated and 135 down-regulated genes,were identified in CCHFV-infected cells.These regulated genes were mainly involved in host processes including defense response to virus,response to stress,regulation of viral process,immune response,metabolism,stimulus,apoptosis and protein catabolic process.Therein,a significant up-regulation of type III interferon(IFN)signaling pathway as well as endoplasmic reticulum(ER)stress response was especially remarkable.Subsequently,representative DEGs from these processes were well validated by RT-qPCR,confirming the RNA-seq results and the typical regulation of IFN responses and ER stress by CCHFV.Furthermore,we demonstrate that not only type I but also type III IFNs(even at low dosages)have substantial anti-CCHFV activities.Collectively,the data may provide new and comprehensive insights into the virus-host interactions and particularly highlights the potential role of type III IFNs in restricting CCHFV,which may help inform further mechanistic delineation of the viral infection and development of anti-CCHFV strategies.

Mesoporous silica nanoparticles for drug and gene delivery

Mesoporous silica nanoparticles(MSNs) are attracting increasing interest for potential biomedical applications. With tailored mesoporous structure, huge surface area and pore volume,selective surface functionality, as well as morphology control, MSNs exhibit high loading capacity for therapeutic agents and controlled release properties if modified with stimuli-responsive groups, polymers or proteins. In this review article, the applications of MSNs in pharmaceutics to improve drug bioavailability, reduce drug toxicity, and deliver with cellular targetability are summarized. Particularly,the exciting progress in the development of MSNs-based effective delivery systems for poorly soluble drugs, anticancer agents, and therapeutic genes are highlighted.

Isolation,Characterization,and Phylogenetic Analysis of Two New Crimean-Congo Hemorrhagic Fever Virus Strains from the Northern Region of Xinjiang Province,China

Crimean-Congo hemorrhagic fever(CCHF)caused by the CCHF virus(CCHFV)is a tick-borne natural focal disease with a mortality rate of approximately 50%.CCHFV is widely prevalent in Africa,southern Asia,the Middle East,and southeast Europe.CCHF outbreaks have been reported previously in Xinjiang province,China,especially in its southern region.Epidemiological surveys conducted on ticks and animals have revealed the presence of CCHFV strains in ticks,rodents,and infected individuals from cities and counties in southern Xinjiang.Phylogenetic analyses revealed that the Chinese CCHFV strains belong to one genotype,based on complete sequences of the S segments of its negative-stranded RNA genome.The present study reports two new CCHFV strains isolated from Hyalomma asiaticum asiaticum ticks collected from Fukang City and Wujiaqu City in the northern region of Xinjiang.Viral characteristics and their evolutionary relationships were analyzed through metagenomic and reverse-transcription PCR analyses;these analyses indicated that the genotype of both strains was different from that of other Chinese strains.Furthermore,previous reports of CCHFV in Xinjiang were reviewed and phylogenetic analyses were performed.CCHFV was found to prevail in Fukang City in Junggar Basin for more than 20 years,and that Fukang City and Wujiaqu City are considered natural reservoirs of different genotypes of CCHFV strains.Our findings facilitate the understanding of CCHFV distribution in Xinjiang province and provide insights into the evolutionary relationships among Chinese CCHFV strains.

Novel SFTSV Phylogeny Reveals New Reassortment Events and Migration Routes

Severe fever with thrombocytopenia syndrome virus(SFTSV),the causative agent of a febrile human disease,was first identified from central and eastern provinces in China,and later in Japan and South Korea.Hubei Province is one of the major SFTS epidemic areas in the central part of China.This study reported the isolation of 11 new SFTSV strains from patients in Hubei Province collected in 2017.Extensive phylogenetic analyses were conducted based on the complete coding sequences of SFTSV segments including the new strains.It was suggested that five different SFTSV genotypes were circulating in Hubei,and 15 reassortment patterns and migration pathways correlated with each genotype were identified,which was more than previously recognized.Hubei Province was more involved in the evolutionary events of SFTSV than that previously thought in which the evolutionary events of SFTSV were reported to be independent from those in other epidemic regions.Further divergence of SFTSV strains was suggested by pairwise comparison of SFTSV sequences from each genotype and sequence identity normalized to representative strain in genotype C1.Subsequently,amino acid variations specific for genotype(s),strain(s),or cluster(s)were inspected,which may be related to differential biological activity of SFTSV strains/genotypes.In conclusion,we analyzed the current status of SFTSV phylogeny in Hubei Province and discussed the possible events correlated to SFTSV evolution.It provided an in-depth insight into SFTSV evolution,raising concerns for the use of proper SFTSV strains in future studies.

A new luciferase immunoprecipitation system assay provided serological evidence for missed diagnosis of severe fever with thrombocytopenia syndrome

Severe fever with thrombocytopenia syndrome(SFTS),caused by SFTS virus(SFTSV)infection,was first reported in 2010 in China with an initial fatality of up to 30%.The laboratory confirmation of SFTSV infection in terms of detection of viral RNA or antibody levels is critical for SFTS diagnosis and therapy.In this study,a new luciferase immunoprecipitation system(LIPS)assay based on p REN2 plasmid expressing SFTSV NP gene and tagged with Renilla luciferase(Rluc),was established and used to investigate the levels of antibody responses to SFTSV.Totally 464 serum samples from febrile patients were collected in the hospital of Shaoxing City in Zhejiang Province in 2019.The results showed that 82 of the 464 patients(17.7%)had antibody response to SFTSV,which were further supported by immunofluorescence assays(IFAs).Further,q RT-PCR and microneutralization tests showed that among the 82 positive cases,15 patients had viremia,10 patients had neutralizing antibody,and one had both(totally 26 patient).However,none of these patients were diagnosed as SFTS in the hospital probably because of their mild symptoms or subclinical manifestations.All the results indicated that at least the 26 patients having viremia or neutralizing antibody were the missed diagnosis of SFTS cases.The findings suggested the occurrence of SFTS and the SFTS incidence were higher than the reported level in Shaoxing in 2019,and that LIPS may provide an alternative strategy to confirm SFTSV infection in the laboratory.

Identification, Isolation, and Characterization of an Ectromelia Virus New Strain from an Experimental Mouse

Dear Editor,Ectromelia virus(ECTV)is a large double-stranded DNA virus belonging to the genus Orthopoxviruses in the family Poxviridae.It is the causative agent of mousepox,which is a lethal,acute toxic disease with high mortality rate in most strains of laboratory mice.It was first discovered in 1930 when mice were first used as animal models(Marchal 1930).

Risk of infection with arboviruses in a healthy population in Pakistan based on seroprevalence

Infectious diseases caused by arboviruses are a public health concern in Pakistan.However,studies on data prevalence and threats posed by arboviruses are limited.This study investigated the seroprevalence of arboviruses in a healthy population in Pakistan,including severe fever with thrombocytopenia syndrome virus(SFTSV),Crimean-Congo hemorrhagic fever virus(CCHFV),Tamdy virus(TAMV),and Karshi virus(KSIV)based on a newly established luciferase immunoprecipitation system(LIPS)assays,and Zika virus(ZIKV)by enzyme-linked immunosorbent assays(ELISA).Neutralizing activities against these arboviruses were further examined from the antibody positive samples.The results showed that the seroprevalence of SFTSV,CCHFV,TAMV,KSIV,and ZIKV was 17.37%,7.58%,4.41%,1.10%,and 6.48%,respectively,and neutralizing to SFTSV(1.79%),CCHFV(2.62%),and ZIKV(0.69%)were identified,as well as to the SFTSV-related Guertu virus(GTV,0.83%).Risk factors associated with the incidence of exposure and levels of antibody response were analyzed.Moreover,co-exposure to different arboviruses was demonstrated,as thirty-seven individuals were having antibodies against multiple viruses and thirteen showed neutralizing activity.Males,individuals aged
40 years,and outdoor workers had a high risk of exposure to arboviruses.All these results reveal the substantial risks of infection with arboviruses in Pakistan,and indicate the threat from co-exposure to multiple arboviruses.The findings raise the need for further epidemiologic investigation in expanded regions and populations and the necessity to improve health surveillance in Pakistan.