The dysregulation of autophagy,an evolutionarily conserved lysosomal degradation process,has been implicated in a wide variety of human diseases,and thus,small chemicals that modulate autophagy have therapeutic potent...The dysregulation of autophagy,an evolutionarily conserved lysosomal degradation process,has been implicated in a wide variety of human diseases,and thus,small chemicals that modulate autophagy have therapeutic potential.Here,we assessed the ability of active components isolated from Bupleurum falcatum,a popular Chinese herb,to modulate autophagy.We found that saikosaponin D(SsD)and A(SsA)but not C(SsC)potently and reversibly inhibited the fusion of autophagosomes and lysosomes,resulting in the accumulation of autophagosomes,an increased lysosomal pH,and TFEB nuclear translocation.RAB5A knockdown or the expression of a dominant-negative RAB5 mutant significantly reduced the ability of SsD or SsA to block autophagy.Enterovirus A71(EV-A71),the cause of hand-foot-mouth disease,has been shown to induce autophagy.We found that SsD potently inhibited EV-A71 RNA replication and subsequent viral protein synthesis,thereby preventing EV-A71-induced cell death.ATG5 knockdown inhibited EV-A71 viral protein synthesis,whereas autophagy induction by rapamycin promoted synthesis.Taken together,our data indicate that SsD and SsA are potent late-stage autophagy inhibitors that can be used to prevent EV-A71 infection.展开更多
基金This work was supported by Hong Kong Research Grant Council(RGC)grants(785213,17126614,and 11101717),NSFC(21778045)the CAS-Croucher Funding Scheme,the Guangdong-Hong Kong joint innovation Research Scheme(2016A050503010)+1 种基金a Shenzhen government research grant(JCYJ20160229165235739 and JCYJ20170413141331470)to J.Y.it was partly supported by GRF(14105214)and NSFC(81671995,81471964)grants to M.L.H.
文摘The dysregulation of autophagy,an evolutionarily conserved lysosomal degradation process,has been implicated in a wide variety of human diseases,and thus,small chemicals that modulate autophagy have therapeutic potential.Here,we assessed the ability of active components isolated from Bupleurum falcatum,a popular Chinese herb,to modulate autophagy.We found that saikosaponin D(SsD)and A(SsA)but not C(SsC)potently and reversibly inhibited the fusion of autophagosomes and lysosomes,resulting in the accumulation of autophagosomes,an increased lysosomal pH,and TFEB nuclear translocation.RAB5A knockdown or the expression of a dominant-negative RAB5 mutant significantly reduced the ability of SsD or SsA to block autophagy.Enterovirus A71(EV-A71),the cause of hand-foot-mouth disease,has been shown to induce autophagy.We found that SsD potently inhibited EV-A71 RNA replication and subsequent viral protein synthesis,thereby preventing EV-A71-induced cell death.ATG5 knockdown inhibited EV-A71 viral protein synthesis,whereas autophagy induction by rapamycin promoted synthesis.Taken together,our data indicate that SsD and SsA are potent late-stage autophagy inhibitors that can be used to prevent EV-A71 infection.
