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.

MYC promotes global transcription in part by controlling P-TEFb complex formation via DNA-binding independent inhibition of CDK9 SUMOylation

MYC is an oncogenic transcription factor with a novel role in enhancing global transcription when overexpressed. However, how MYC promotes global transcription remains controversial. Here, we used a series of MYC mutants to dissect the molecular basis for MYC-driven global transcription. We found that MYC mutants deficient in DNA binding or known transcriptional activation activities can still promote global transcription and enhance serine 2 phosphorylation(Ser2P) of the RNA polymerase(Pol) II Cterminal domain(CTD), a hallmark of active elongating RNA Pol II. Two distinct regions within MYC can promote global transcription and Ser2P of Pol II CTD. The ability of various MYC mutants to promote global transcription and Ser2P correlates with their ability to suppress CDK9 SUMOylation and enhance positive transcription elongation factor b(P-TEFb) complex formation. We showed that MYC suppresses CDK9 SUMOylation by inhibiting the interaction between CDK9 and SUMO enzymes including UBC9 and PIAS1. Furthermore, MYC's activity in enhancing global transcription positively contributes to its activity in promoting cell proliferation and transformation. Together, our study demonstrates that MYC promotes global transcription, at least in part, by promoting the formation of the active P-TEFb complex via a sequence-specific DNA-binding activity-independent manner.

Temporal profiling of plasma cytokines,chemokines and growth factors from mild,severe and fatal COVID-19 patients

Dear Editor,In December 2019,a novel coronavirus that is related to severe acute respiratory syndrome coronavirus(SARS-CoV)and Middle East respiratory syndrome coronavirus(MERS-CoV)in phylogenetic distance was identified.1 This virus,which was later designated as SARS-CoV-2,also causes acute respiratory disease syndrome(ARDS)termed coronavirus disease 2019(COVID-19),which was declared as a pandemic by the World Health Organization in March 2020.

Enhanced host immune responses in presence of HCV facilitate HBV clearance in coinfection

Hepatitis B virus(HBV)/Hepatitis C virus(HCV)coinfection is frequently observed because of the common infection routine.Despite the reciprocal inhibition exerted by HBV and HCV genomes,the coinfection of HBV and HCV is associated with more severe forms of liver diseases.However,the complexity of viral interference and underlying pathological mechanism is still unclarified.With the demonstration of absence of direct viral interplay,some in vitro studies suggest the indirect effects of viral-host interaction on viral dominance outcome.Here,we comprehensively investigated the viral replication and host immune responses which might mediate the interference between viruses in HBV/HCV coinfected Huh7-NTCP cells and immunocompetent HCV human receptors transgenic ICR mice.We found that presence of HCV significantly inhibited HBV replication in vitro and in vivo irrespective of the coinfection order,while HBV did not affect HCV replication.Pathological alteration was coincidently reproduced in coinfected mice.In addition to the participation of innate immune response,an involvement of HCV in up-regulating HBV-specific immune responses was described to facilitate HBV clearance.Our systems partially recapitulate HBV/HCV coinfection and unveil the uncharacterized adaptive anti-viral immune responses during coinfection,which renews the knowledge on the nature of indirect viral interaction during HBV/HCV coinfection.

Soluble CD4 effectively prevents excessive TLR activation of resident macrophages in the onset of sepsis

T lymphopenia,occurring in the early phase of sepsis in response to systemic inflammation,is commonly associated with morbidity and mortality of septic infections.We have previously shown that a sufficient number of T cells is required to constrain Toll-like receptors(TLRs)mediated hyperinflammation.However,the underlying mechanisms remains unsolved.Herein,we unveil that CD4^(+)T cells engage with MHC II of macrophages to downregulate TLR pro-inflammatory signaling.

Human cytomegalovirus infection dysregulates neural progenitor cell fate by disrupting Hes1 rhythm and down-regulating its expression

Human cytomegalovirus(HCMV) infection is a leading cause of birth defects, primarily affecting the central nervous system and causing its maldevelopment. As the essential downstream effector of Notch signaling pathway, Hes1, and its dynamic expression, plays an essential role on maintaining neural progenitor/stem cells(NPCs) cell fate and fetal brain development. In the present study, we reported the first observation of Hes1 oscillatory expression in human NPCs, with an approximately1.5 hour periodicity and a Hes1 protein half-life of about 17(17.6 ± 0.2) minutes. HCMV infection disrupts the Hes1 rhythm and down-regulates its expression. Furthermore, we discovered that depleting Hes1 protein disturbed NPCs cell fate by suppressing NPCs proliferation and neurosphere formation, and driving NPCs abnormal differentiation. These results suggested a novel mechanism linking disruption of Hes1 rhythm and down-regulation of Hes1 expression to neurodevelopmental disorders caused by congenital HCMV infection.

Correction to:Human cytomegalovirus DNA and immediate early protein 1/2 are highly associated with glioma and prognosis

In the original publication the email addresses of corresponding authors have not been displayed.The correct email addresses of corresponding authors are provided in this correction.Fang-Cheng Li(sjwklfc@126.com),Fei Hu(neuron111@163.com),Min-Hua Luo(luomh@wh.iov.cn).

Human cytomegalovirus DNA and immediate early protein 1/2 are highly associated with glioma and prognosis

Dear Editor,Gliomas are the most common brain tumors in adults which encompass all primary central nervous system(CNS)tumors of glial cell origin.The World Health Organization(WHO)classifies gliomas into four grades based on the histologic/prognostic features.Because of the unclear etiol-ogy and pathogenesis,therapeutic efficacy and prognosis is poor.

Ellipsoidal porous patch with anisotropic cell inducing ability for inhibiting skin scar formation

Scar formation has always been a difficult point to overcome in the field of clinical wound care.Here,we present an ellipsoidal porous patch with cell inducing ability for inhibiting scar formation.The patch was prepared by stretching a poly(lactic-co-glycolic acid)(PLGA)inverse opal film at the glass transition temperature to form a neatly arranged three-dimensional ellipsoidal porous structure.Such anisotropic structure showed dramatic capability in directing cell growth and arrangement by reconstructing cell morphology.Besides,the prolifera-tion of cells growing on the stretched patch was significantly suppressed without cell cytotoxicity.In addition,benefitting from the abundant and connected nanopores,the patch could be imparted with a potent ability to promote cell migration by encapsulating fibroblast growth factor 2(FGF2)via the second filling of functional gelatin methacryloyl(GelMA)hydrogel into its scaffold.In a typical scar model,we have demonstrated that the resultant patch performed well in inhibiting scar formation characterized by inhibiting the excessive proliferation of fibroblasts,decreasing the deposition of type I collagen,reducing the scar index and achieved complete tissue reconstruction.These results indicate the anisotropic inverse opal patch has an excellent application prospect in inhibiting scar formation during wound repair.