非酒精性脂肪性肝炎(nonalcoholic steatohepatitis,NASH)逐渐成为发病率最高的慢性肝病类型。NASH发病常常伴随全身代谢综合征,疾病进展具有发生肝硬化甚至肝癌的高风险。然而,目前临床上尚无一种获批的针对NASH的有效治疗药物。我们...非酒精性脂肪性肝炎(nonalcoholic steatohepatitis,NASH)逐渐成为发病率最高的慢性肝病类型。NASH发病常常伴随全身代谢综合征,疾病进展具有发生肝硬化甚至肝癌的高风险。然而,目前临床上尚无一种获批的针对NASH的有效治疗药物。我们的最新研究结果发现,天然免疫重要分子CFLAR[CASP8 and FADD(Fas-associating protein with death domain)-like apoptosis regulator]直在NASH疾病进程中的关键负调控作用。深入的分子机制探索证实,CFLAR接靶向激酶MAP3K5[mitogen-activated protein kinase kinase kinase 5,也称为ASK1(apoptosis signal-regulating kinase 1)]并阻断其N-端二聚化,从而抑制ASK1和激酶MAPK8[mitogen-activated protein kinase 8,也称为JNK1(c-Jun N-terminal kinase 1)]的信号通路。此外,我们鉴定出源于CFLAR的一个小肽片段(S1)可以有效发挥CFLAR对ASK1的抑制作用。应用CFLAR(S1)治疗可有效改善并逆转小鼠和猴子中的NASH及并发的代谢综合征。综上所述,我们发现,CFLAR是控制NASH疾病进展的关键抑制子。CFLAR(S1)特异性抑制ASK 1激活的作用机制,为开发或筛选NASH的靶向治疗药物提供了可行的新方案。展开更多
Background:Circular RNAs(circR NAs)are covalently closed single-stranded RNAs with multiple biological functions.CircRNA.0007127 is derived from the carbon catabolite repression 4-negative on TATA-less(CCR4-NOT)comple...Background:Circular RNAs(circR NAs)are covalently closed single-stranded RNAs with multiple biological functions.CircRNA.0007127 is derived from the carbon catabolite repression 4-negative on TATA-less(CCR4-NOT)complex subunit2(CNOT2),which was found to regulate tumor cell apoptosis through caspase pathway.Methods:Potential circR NA.0007127 target microRNAs(miRNAs)were analyzed by miRanda,TargetScan,and RNAhybrid software,and the miRNAs with binding sites for apoptosis-related genes were screened.The roles of circR NA.0007127 and its downstream target,microR NA(miR)-513a-5p,were validated by quantitative real-time polymerase chain reaction(qPCR),flow cytometry,mitochondrial membrane potential,immunofluorescence,western blot,and caspase-8(CASP8)protein activity in vitro in HO-induced K-562 cells.The circRNA.0007127-miR-513a-5p and CASP8-miR-513a-5p interactions were verified by luciferase reporter assays.Results:Silencing circRNA.0007127 decreased cell apoptosis by inhibiting CASP8 pathway activation in K-562 cells.Compared with the control group,the expression of CASP8 was reduced by 50%and the 43-kD fragment of CASP8 protein was significantly reduced(P≤0.05).The luciferase reporting assay showed that circRNA.0007127 combined with miR-513a-5p or CASP8,with extremely significant differences(P≤0.001).The overexpression of miR-513a-5p inhibited the gene expression level of CASP8in a human myeloid leukemia cell model(75%change)and the level of a 43-kD fragment of CASP8 protein(P small-interfering RNA(siRNA)and the miR-≤0.01).The rescue experiment showed that cotransfection with circRNA.0007127513a-5p inhibitor increased CASP8 gene expression and the apoptosis rate,suggesting that the miR-513a-5p inhibitor is a circRNA.0007127siRNA antagonist.Conclusions:CircRNA.0007127 regulates K-562 cell apoptosis through the miR-513a-5p/CASP8 axis,which can serve as a novel powerful molecular target for K-562 cells.展开更多
文摘非酒精性脂肪性肝炎(nonalcoholic steatohepatitis,NASH)逐渐成为发病率最高的慢性肝病类型。NASH发病常常伴随全身代谢综合征,疾病进展具有发生肝硬化甚至肝癌的高风险。然而,目前临床上尚无一种获批的针对NASH的有效治疗药物。我们的最新研究结果发现,天然免疫重要分子CFLAR[CASP8 and FADD(Fas-associating protein with death domain)-like apoptosis regulator]直在NASH疾病进程中的关键负调控作用。深入的分子机制探索证实,CFLAR接靶向激酶MAP3K5[mitogen-activated protein kinase kinase kinase 5,也称为ASK1(apoptosis signal-regulating kinase 1)]并阻断其N-端二聚化,从而抑制ASK1和激酶MAPK8[mitogen-activated protein kinase 8,也称为JNK1(c-Jun N-terminal kinase 1)]的信号通路。此外,我们鉴定出源于CFLAR的一个小肽片段(S1)可以有效发挥CFLAR对ASK1的抑制作用。应用CFLAR(S1)治疗可有效改善并逆转小鼠和猴子中的NASH及并发的代谢综合征。综上所述,我们发现,CFLAR是控制NASH疾病进展的关键抑制子。CFLAR(S1)特异性抑制ASK 1激活的作用机制,为开发或筛选NASH的靶向治疗药物提供了可行的新方案。
基金supported by the Guangzhou Science and Technology Plan Project(No.201904010027)the Key Clinical Technology Program of Guangzhou(No.2019ZD18),China。
文摘Background:Circular RNAs(circR NAs)are covalently closed single-stranded RNAs with multiple biological functions.CircRNA.0007127 is derived from the carbon catabolite repression 4-negative on TATA-less(CCR4-NOT)complex subunit2(CNOT2),which was found to regulate tumor cell apoptosis through caspase pathway.Methods:Potential circR NA.0007127 target microRNAs(miRNAs)were analyzed by miRanda,TargetScan,and RNAhybrid software,and the miRNAs with binding sites for apoptosis-related genes were screened.The roles of circR NA.0007127 and its downstream target,microR NA(miR)-513a-5p,were validated by quantitative real-time polymerase chain reaction(qPCR),flow cytometry,mitochondrial membrane potential,immunofluorescence,western blot,and caspase-8(CASP8)protein activity in vitro in HO-induced K-562 cells.The circRNA.0007127-miR-513a-5p and CASP8-miR-513a-5p interactions were verified by luciferase reporter assays.Results:Silencing circRNA.0007127 decreased cell apoptosis by inhibiting CASP8 pathway activation in K-562 cells.Compared with the control group,the expression of CASP8 was reduced by 50%and the 43-kD fragment of CASP8 protein was significantly reduced(P≤0.05).The luciferase reporting assay showed that circRNA.0007127 combined with miR-513a-5p or CASP8,with extremely significant differences(P≤0.001).The overexpression of miR-513a-5p inhibited the gene expression level of CASP8in a human myeloid leukemia cell model(75%change)and the level of a 43-kD fragment of CASP8 protein(P small-interfering RNA(siRNA)and the miR-≤0.01).The rescue experiment showed that cotransfection with circRNA.0007127513a-5p inhibitor increased CASP8 gene expression and the apoptosis rate,suggesting that the miR-513a-5p inhibitor is a circRNA.0007127siRNA antagonist.Conclusions:CircRNA.0007127 regulates K-562 cell apoptosis through the miR-513a-5p/CASP8 axis,which can serve as a novel powerful molecular target for K-562 cells.
