β-escin reverses multidrug resistance through inhibition of the GSK3β/β-catenin pathway in cholangiocarcinoma

AIM: To develop a safe and effective agent for cholangiocarcinoma(CCA) chemotherapy. METHODS: A drug combination experiment was conducted to determine the effects of β-escin in c o m b i n a t i o n w i t h c h e m o t h e ra p y o n C C A c e l l s. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay was performed to determine the effects of β-escin and common chemotherapeutics on the proliferation of human CCA cells(QBC939, Sk-Ch A-1, and MZ-Ch A-1). Immunocytochemistry was used to detect the expression of P-glycoprotein(P-gp) protein. Luciferase reporter assay was used to detect the activation of the Wnt/β-catenin pathway. The protein levels of P-gp, p S9-GSK3β, p T216-GSK3β, GSK3β, β-catenin, and p-β-catenin were further confirmed by western blotting.RESULTS: The drug sensitivity of QBC939 and QBC939/5-fluorouracil(5-FU) cells to 5-FU, vincristine sulfate(VCR), or mitomycin C was significantly enhanced by β-escin compared with either agent alone(P < 0.05). In addition, the combination of β-escin(20 μmol/L) with 5-FU and VCR was synergic with a combination index < 1. Further investigation found that the m RNA and protein expression of P-gp was downregulated by β-escin. Moreover, β-escin induced GSK3β phosphorylation at Tyr-216 and dephosphorylation at Ser-9, resulting in phosphorylation and degradation of β-catenin. Interestingly, activation of the GSK3β/β-catenin pathway induced by Wnt3 a resulted in upregulation of P-gp, which was effectively abolished by β-escin, indicating that β-escin down-regulated P-gp expression in a GSK3β-dependent manner.CONCLUSION: β-escin was a potent reverser of P-gpdependent multidrug resistance, with said effect likely being achieved via inhibition of the GSK3β/β-catenin pathway and thus suggesting a promising strategy of developing combination drugs for CCA.

The potential epidemic threat of Ebola virus and the development of a preventive vaccine

Ebola virus(EBOV)is classified as a category A pathogen as it causes viral hemorrhagic fever,one of the most-deadly virus-related diseases.Since its discovery in 1976,EBOV has caused a number of global public health incidents,which have posed a serious threat to both humans and non-human primates.Thus,numerous preventive vaccine studies are underway,including research on inactivated vaccines,DNA vaccines,subunit vaccines,virus-like particles,Venezuelan equine encephalitis virus replicon particles,and several viral vector vaccines.The vesicular stomatitis virus-based vaccine Ervebo was recently approved by the Food and Drug Administration and the European Union,and several other vaccines have also been proven to confer potent protection in non-human primates against EBOV lethal challenge.This review provides a brief background of EBOV,with a focus on the epidemiology,available animal models,and advances in preventive approaches for EBOV infection.

Different pathogenesis of SARS-CoV-2 Omicron variant in wild-type laboratory mice and hamsters

Dear Editor,The COVID-19 pandemic caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)continues to disrupt global public health since its first report in December 2019,resulting in more than 380 billion confirmed cases including nearly 5.7 billion deaths worldwide(https://covidl9.who.int).

Intranasal delivery of replicating mRNA encoding neutralizing antibody against SARS-CoV-2 infection in mice

The lung is the prophylaxis target against SARS-CoV-2 infection,and neutralizing antibodies are a leading class of biological products against various infectious viral pathogen.In this study,we develop a safe and cost-effective platform to express neutralizing antibody in the lung with replicating mRNA basing on alphavirus replicon particle(VRP)delivery system,to prevent SARS-CoV-2 infections.First,a modified VEEV replicon with two subgenomic(sg)promoters was engineered to translate the light and heavy chains of antibody simultaneously,for expression and assembly of neutralizing anti-SARS-CoV-2 antibody CB6.Second,the feasibility and protective efficacy of replicating mRNA against SARS-CoV-2 infection were demonstrated through both in vitro and in vivo assays.The lung target delivery with the help of VRP system resulted in efficiently block SARS-CoV-2 infection with reducing viral titer and less tissue damage in the lung of mice.Overall,our data suggests that expressing neutralizing antibodies in the lungs with the help of self-replicating mRNA could potentially be a promising prophylaxis approach against SARS-CoV-2 infection.

Identification of fangchinoline as a broad-spectrum enterovirus inhibitor through reporter virus based high-content screening

Hand,foot,and mouth disease(HFMD)is a common pediatric illness mainly caused by enteroviruses,which are important human pathogens.Currently,there are no available antiviral agents for the therapy of enterovirus infection.In this study,an excellent high-content antiviral screening system utilizing the EV-A71-eGFP reporter virus was developed.Using this screening system,we screened a drug library containing 1042 natural compounds to identify potential EV-A71 inhibitors.Fangchinoline(FAN),a bis-benzylisoquinoline alkaloid,exhibits potential inhibitory effects against various enteroviruses that cause HFMD,such as EV-A71,CV-A10,CV-B3 and CV-A16.Further investigations revealed that FAN targets the early stage of the enterovirus life cycle.Through the selection of FAN-resistant EV-A71 viruses,we demonstrated that the VP1 protein could be a potential target of FAN,as two mutations in VP1(E145G and V258I)resulted in viral resistance to FAN.Our research suggests that FAN is an efficient inhibitor of EV-A71 and has the potential to be a broad-spectrum antiviral drug against human enteroviruses.