Intracellular polyamines(putrescine,spermidine,and spermine)have emerged as important molecules for viral infection;however,how viruses activate polyamines biosynthesis to promote viral infection remains unclear.Ornit...Intracellular polyamines(putrescine,spermidine,and spermine)have emerged as important molecules for viral infection;however,how viruses activate polyamines biosynthesis to promote viral infection remains unclear.Ornithine decarboxylase 1(ODC1)and its antienzyme 1(OAZ1)are major regulators of polyamine biosynthesis in animal cells.Here,we report that rice yellow stunt virus(RYSV),a plant rhabdovirus,could activate putrescine biosynthesis in leafhoppers to promote viral propagation by inhibiting OAZ1 expression.We observed that the reduction of putrescine biosynthesis by treatment with difluormethylornithine(DFMO),a specific nontoxic inhibitor of ODC1,or with in vitro synthesized dsRNAs targeting ODC1 mRNA could inhibit viral infection.In contrast,the supplement of putrescine or the increase of putrescine biosynthesis by treatment with ds RNAs targeting OAZ1 mRNA could facilitate viral infection.We further determined that both RYSV matrix protein M and ODC1 directly bind to the ODC-binding domain at the C-terminus of OAZ1.Thus,viral propagation in leafhoppers would decrease the ability of OAZ1 to target and mediate the degradation of ODC1,which finally activates putrescine production to benefit viral propagation.This work reveals that polyamine-metabolizing enzymes are directly exploited by a vector-borne virus to increase polyamine production,thereby facilitating viral infection in insect vectors.展开更多
Background:Electroencephalogram(EEG)is an important tool for the diagnosis of herpes simplex virus encephalitis(HSE).However,the diagnosis of non-convulsive status epilepticus(NCSE)in HSE is challenging without the he...Background:Electroencephalogram(EEG)is an important tool for the diagnosis of herpes simplex virus encephalitis(HSE).However,the diagnosis of non-convulsive status epilepticus(NCSE)in HSE is challenging without the help of continuous video EEG(CVEEG),and whether EEG is a predictor of outcome remains controversial.Case presentation:A 63-year-old woman presented with a 5 day history of fever,coma and seizures.Results of EEG,magnetic resonance imaging and polymerase chain reaction(PCR)in cerebrospinal fluid(CSF)were suggestive of herpes simplex encephalitis-1(HSE-1).Preliminary EEG showed periodic discharges at the prefrontal and temporal lobes,which were particularly synchronized with intermittent lip smacking movements,and the discharges were terminated by diazepam.After 2-week treatment with acyclovir,high-dose hormone pulse therapy and high-dose immunoglobulin therapy,the CSF was improved,but the patient’s consciousness became worsen,consistent with the diffuse slow waves in the delta range and low voltage of EEG activity.In the following 1 month,the patient had non-responsiveness to pain and sound as shown by CVEEG with diffuse slow waves.Sometimes paroxysmal very slow waves(0.5–1 Hz)were synchronized with intermittent paroxysmal eye movements,pupil abnormality,and sweating in the frontal area.After 2 months of treatment,the EEG abnormalities improved to have alpha rhythm.Conclusion:The CVEEG not only helps identify NCSE but can also be used to monitor HSE progression.展开更多
基金supported by the National Natural Science Foundation of China(31871931)the Fujian Agriculture and Forestry University Outstanding Young Scientists Project(xjq201705)National Key Research and Development Project of China(2018YFD0200306)。
文摘Intracellular polyamines(putrescine,spermidine,and spermine)have emerged as important molecules for viral infection;however,how viruses activate polyamines biosynthesis to promote viral infection remains unclear.Ornithine decarboxylase 1(ODC1)and its antienzyme 1(OAZ1)are major regulators of polyamine biosynthesis in animal cells.Here,we report that rice yellow stunt virus(RYSV),a plant rhabdovirus,could activate putrescine biosynthesis in leafhoppers to promote viral propagation by inhibiting OAZ1 expression.We observed that the reduction of putrescine biosynthesis by treatment with difluormethylornithine(DFMO),a specific nontoxic inhibitor of ODC1,or with in vitro synthesized dsRNAs targeting ODC1 mRNA could inhibit viral infection.In contrast,the supplement of putrescine or the increase of putrescine biosynthesis by treatment with ds RNAs targeting OAZ1 mRNA could facilitate viral infection.We further determined that both RYSV matrix protein M and ODC1 directly bind to the ODC-binding domain at the C-terminus of OAZ1.Thus,viral propagation in leafhoppers would decrease the ability of OAZ1 to target and mediate the degradation of ODC1,which finally activates putrescine production to benefit viral propagation.This work reveals that polyamine-metabolizing enzymes are directly exploited by a vector-borne virus to increase polyamine production,thereby facilitating viral infection in insect vectors.
基金the General Project of National Natural ScienceFoundation of China(Grant No.81901311).
文摘Background:Electroencephalogram(EEG)is an important tool for the diagnosis of herpes simplex virus encephalitis(HSE).However,the diagnosis of non-convulsive status epilepticus(NCSE)in HSE is challenging without the help of continuous video EEG(CVEEG),and whether EEG is a predictor of outcome remains controversial.Case presentation:A 63-year-old woman presented with a 5 day history of fever,coma and seizures.Results of EEG,magnetic resonance imaging and polymerase chain reaction(PCR)in cerebrospinal fluid(CSF)were suggestive of herpes simplex encephalitis-1(HSE-1).Preliminary EEG showed periodic discharges at the prefrontal and temporal lobes,which were particularly synchronized with intermittent lip smacking movements,and the discharges were terminated by diazepam.After 2-week treatment with acyclovir,high-dose hormone pulse therapy and high-dose immunoglobulin therapy,the CSF was improved,but the patient’s consciousness became worsen,consistent with the diffuse slow waves in the delta range and low voltage of EEG activity.In the following 1 month,the patient had non-responsiveness to pain and sound as shown by CVEEG with diffuse slow waves.Sometimes paroxysmal very slow waves(0.5–1 Hz)were synchronized with intermittent paroxysmal eye movements,pupil abnormality,and sweating in the frontal area.After 2 months of treatment,the EEG abnormalities improved to have alpha rhythm.Conclusion:The CVEEG not only helps identify NCSE but can also be used to monitor HSE progression.
