Dof(DNA-binding with one finger)蛋白是植物特有的一类转录因子,在植物生长发育过程中起着重要的作用。在其N-末端有一个52氨基酸残基组成的高度保守的C2-C2单锌指结构,称为Dof保守域,能够特异性的识别植物启动子序列中的AAAG/CTTT作...Dof(DNA-binding with one finger)蛋白是植物特有的一类转录因子,在植物生长发育过程中起着重要的作用。在其N-末端有一个52氨基酸残基组成的高度保守的C2-C2单锌指结构,称为Dof保守域,能够特异性的识别植物启动子序列中的AAAG/CTTT作用元件,从而激活或抑制植物基因的表达;其C-末端的转录调控结构域,氨基酸序列较为多变,不具有保守性,是Dof蛋白在植物中功能多样性的基础;同时Dof蛋白也具有和蛋白相互作用的功能。在过去的十几年里,大量的Dof基因被克隆鉴定或从基因组数据库中预测出来,Dof蛋白在植物生长发育中的作用也受到更多关注。本文就Dof转录因子的特点,各物种中已经报道的Dof转录因子的数目、系统进化关系和分类及其生物学功能的进展进行了综述。展开更多
Based on sequencing of part clones in a root subtractive cDNA library, an expressed sequence tag （EST） sharing high similarity to a rice C2H2 zinc finger transcription factor （ZFP15） was obtained in wheat. Through...Based on sequencing of part clones in a root subtractive cDNA library, an expressed sequence tag （EST） sharing high similarity to a rice C2H2 zinc finger transcription factor （ZFP15） was obtained in wheat. Through bioinformatics approach, the wheat C2H2-type ZFP gene referred to TaZFP15 has been identified and characterized. As a full-length cDNA of 670 bp, TaZFP15 has an open reading frame of 408 bp and encodes a 135-aa polypeptide. TaZFP15 contains two C2H2 zinc finger domains and each one has a conserved motif QALGGH. The typical L-box, generally identified in the C2H2 type transcription factors, has also been found in TaZFP15. Phylogenetic analysis suggested that TaZFP15 shares high similarities with rice ZFP15 （GenBank accession no. AY286473）, maize ZFP （GenBank accession no. NM_001159094） and a subset of other zinc-finger transcription factor genes in plant species. The expression of TaZFP15 was up-regulated by starved-Pi stress, showing a pattern to be gradually elevated along with the progression of the Pi-stress in a 23-h treatment regime. Similarly, the transcripts of TaZFP15 in roots were also induced by nitrogen deficiency, and abiotic stresses of drought and salinity. No responses of TaZFP15 were detected in roots to nutrition deficiencies of P, Zn, and Ca, and the external treatment of abscisic acid （ABA）. TaZFP15 could be specifically amplified in genome A, B, and D, and without variability in the sequences, suggesting that TaZFP15 has multi-copies in the homologous hexaploid species. Transgenic analysis in tobacco revealed that up-regulation of TaZFP15 could significantly improve plant dry mass accumulation via increasing the plant phosphorus acquisition capacity under Pi-deficiency condition. The results suggested that TaZFP15 is involved in mediation of signal transductions of diverse external stresses.展开更多
AIM： To investigate the role of SMYD3 in hepatocellular carcinoma （HCC） development and progression and to verify whether its regulation activity was through RIZ1 inactivation. METHODS： Expression of SMYD3 in HCC ...AIM： To investigate the role of SMYD3 in hepatocellular carcinoma （HCC） development and progression and to verify whether its regulation activity was through RIZ1 inactivation. METHODS： Expression of SMYD3 in HCC cell lines and tissues were measured; silencing of SMYD3 by RNA interference （RNAi） was effectuated, hepatoma cell proliferation, migration and apoptosis were tested, with RIZl CpG promoter methylation, and corresponding mRNA expression were investigated. RESULTS： SMYD3 over-expression in HCC was associated with RIZl hypermethylation and mRNA down-expression. Suppression of SMYD3 expression de- methylated RIZl CpG promoter （P 〈 0.01） and increased RIZl mRNA expression （P 〈 0.01）. Consequently, SMYD3 down-expression with RIZl de-methylation strongly inhibited hepatoma cell growth （MTT inhibitory rates： Pgenesil-1-s1 60.95%± 7.97%, Pgenesil-1-s2 72.14% ± 9.68% vs Pgenesil-1-hk 6.89% ± 4.12%, P 〈 0.01） and migration （Pgenesil-1-s1 4.24% ± 1.58%, Pgenesil- 1-s1 4.87% ± 0.73% vs Pgenesil-1 19.03% ± 4.63%, Pgenesil-1-hk 19.95% ±5.21%, P 〈 0.01） and induced apoptosis （FCM subG1 phase Pgenesil-1-s1 19.07% ＋ 1.78%, Pgenesil-1-s2 17.68% ± 2.36% vs Pgenesil-1 0.47% ± 0.12%, Pgenesil-1-hk 1.46% ± 0.28%, P 〈 0.01. TUNEL-positive cells： Pgenesil-1-s1 40.24%± 5.18%, Pgenesil-1-s2 38.48% ± 4.65% vs Pgenesil-1 2.1B% - 1.34%, Pgenesil-1-hk 2.84%± 1.22%, P 〈 0.01） in HepG2 cells. CONCLUSION： These results demonstrate that SMYD3plays a critical role in the carcinogenesis and progression of HCC, The proliferation, migration induction and apoptosis inhibition activities of SMYD3 may be mediated through RIZl CpG promoter hypermethylation.展开更多
N^6-methyladenosine(m6A),a ubiquitous RNA modification,is installed by METTL3-METTL14 complex.The structure of the heterodimeric complex between the methyltransferase domains(MTDs)of METTL3 and METTL14 has been previo...N^6-methyladenosine(m6A),a ubiquitous RNA modification,is installed by METTL3-METTL14 complex.The structure of the heterodimeric complex between the methyltransferase domains(MTDs)of METTL3 and METTL14 has been previously determined.However,the MTDs alone possess no enzymatic activity.Here we present the solution structure for the zinc finger domain(ZFD)of METTL3,the inclusion of which fulfills the methyltransferase activity of METTL3-METTL14.We show that the ZFD specifically binds to an RNA containing 5'-GGACU-3'consensus sequence,but does not to one without.The ZFD thus serves as the target recognition domain,a structural feature previously shown for DNA methyltransferases,and cooperates with the MTDs of METTL3-METTL14 for catalysis.However,the interaction between the ZFD and the specific RNA is extremely weak,with the binding affinity at several hundred micromolar under physiological conditions.The ZFD contains two CCCH-type zinc fingers connected by an anti-parallel P-sheet.Mutational analysis and NMR titrations have mapped the functional interface to a contiguous surface.As a division of labor,the RNA-binding interface comprises basic residues from zinc finger 1 and hydrophobic residues fromβ-sheet and zinc finger 2.Further we show that the linker between the ZFD and MTD of METTL3 is flexible but partially folded,which may permit the cooperation between the two domains during catalysis.Together,the structural characterization of METTL3 ZFD paves the way to elucidate the atomic details of the entire process of RNA m6A modification.展开更多
Secondary walls, which represent the bulk of biomass, have a large impact on plant growth and adaptation to environments. Secondary wall synthesis is switched and regulated by a sophisticated signaling transduction ne...Secondary walls, which represent the bulk of biomass, have a large impact on plant growth and adaptation to environments. Secondary wall synthesis is switched and regulated by a sophisticated signaling transduction network. However, there is limited understanding of these regulatory pathways. Here, we report that ILAl-interacting protein 4 （lIP4） can repress secondary wall synthesis, lIP4 is a phosphorylation sub- strate of an Raf-like MAPKKK, but its function is unknown. By generating lip4 mutants and relevant transgenic plants, we found that lesions in lIP4 enhance secondary wall formation. Gene expression and transactivation activity assays revealed that lIP4 negatively regulates the expression of MYB61 and CESAs but does not bind their promoters, lIP4 interacts with NAC29/NAC31, the upstream regulators of secondary wall synthesis, and suppresses the downstream regulatory pathways in plants. Mutagenesis analyses showed that phosphomimic UP4 proteins translocate from the nucleus to the cytoplasm, which releases interacting NACs and attenuates its repression function. Moreover, we revealed that liPs are evolutionarily conserved and share unreported CCCH motifs, referred to as uncanonical CCCH-tandem zinc-finger proteins. Collectively, our study provides mechanistic insights into the control of secondary wall synthesis and presents an opportunity for improving relevant agronomic traits in crops.展开更多
The Populus euphratica stress responsive zinc-finger protein gene PSTZ, which encodes a protein including typical Cys2/His2 zinc finger structure, was isolated by reverse transcription-polymerase chain reaction from P...The Populus euphratica stress responsive zinc-finger protein gene PSTZ, which encodes a protein including typical Cys2/His2 zinc finger structure, was isolated by reverse transcription-polymerase chain reaction from P. euphratica. Northern hybridization revealed that its expression was induced under drought and salt stress conditions. To examine its function, cDNA of the PSTZ gene, driven by the cauliflower mosaic virus 35S promoter, was cloned into a plant expression vector pBin438 and introduced into tobacco plants. Transgenic tobacco showed an enhanced salt tolerance, suggesting that PSTZ may play a role in plant responsiveness to salt stress.展开更多
BACKGROUND Colorectal cancer(CRC)is the third most common cancer and a significant cause of cancer-related mortality globally.Resistance to chemotherapy,especially during CRC treatment,leads to reduced effectiveness o...BACKGROUND Colorectal cancer(CRC)is the third most common cancer and a significant cause of cancer-related mortality globally.Resistance to chemotherapy,especially during CRC treatment,leads to reduced effectiveness of drugs and poor patient outcomes.Long noncoding RNAs(lncRNAs)have been implicated in various pathophysiological processes of tumor cells,including chemotherapy resistance,yet the roles of many lncRNAs in CRC remain unclear.AIM To identify and analyze the lncRNAs involved in oxaliplatin resistance in CRC and to understand the underlying molecular mechanisms influencing this resistance.METHODS Gene Expression Omnibus datasets GSE42387 and GSE30011 were reanalyzed to identify lncRNAs and mRNAs associated with oxaliplatin resistance.Various bioinformatics tools were employed to elucidate molecular mechanisms.The expression levels of lncRNAs and mRNAs were assessed via quantitative reverse transcription-polymerase chain reaction.Functional assays,including MTT,wound healing,and Transwell,were conducted to investigate the functional implications of lncRNA alterations.Interactions between lncRNAs and trans-cription factors were examined using RIP and luciferase reporter assays,while Western blotting was used to confirm downstream pathways.Additionally,a xenograft mouse model was utilized to study the in vivo effects of lncRNAs on chemotherapy resistance.RESULTS LncRNA prion protein testis specific(PRNT)was found to be upregulated in oxaliplatin-resistant CRC cell lines and negatively correlated with homeodomain interacting protein kinase 2(HIPK2)expression.PRNT was demonstrated to sponge transcription factor zinc finger protein 184(ZNF184),which in turn could regulate HIPK2 expression.Altered expression of PRNT influenced CRC cell sensitivity to oxaliplatin,with overexpression leading to decreased sensitivity and decreased expression reducing resistance.Both RIP and luciferase reporter assays indicated that ZNF184 and HIPK2 are targets of PRNT.The PRNT/ZNF184/HIPK2 axis was implicated in promoting CRC prog展开更多
AIM： To investigate the effect of zinc finger protein A20 on chronic liver allograft dysfunction in rats. METHODS： AIIogeneic liver transplantation from DA rats to Lewis rats was performed. Chronic liver allograft d...AIM： To investigate the effect of zinc finger protein A20 on chronic liver allograft dysfunction in rats. METHODS： AIIogeneic liver transplantation from DA rats to Lewis rats was performed. Chronic liver allograft dysfunction was induced in the rats by administering low-dose tacrolimus at postoperative day （POD） 5. Hepatic overexpression of A20 was achieved by recom- binant adenovirus （rAd.）-mediated gene transfer ad- ministered intravenously every 10 d starting from POD 10. The recipient rats were injected with physiologi- cal saline, rAdEasy-A20 （1 × 109 pfu/30 g weight） or rAdEasy （1 × 109 pfu/30 g weight） every 10 d through the tail vein for 3 mo starting from POD 10. Liver tissue samples were harvested on POD 30 and POD 60. RESULTS： Liver-transplanted rats treated with only tacrolimus showed chronic allograft dysfunction with severe hepatic fibrosis. A20 overexpression ameliorated the effects on liver function, attenuated liver allograft fibrosis and prolonged the survival of the recipient rats. Treatment with A20 suppressed hepatic protein pro- duction of tumor growth factor （TGF）-β1, interleukin- 113, caspase-8, CD40, CD40L, intercellular adhesion molecule-i, vascular cell adhesion molecule-1 and E-selectin. A20 treatment suppressed liver cell apopto- sis and inhibited nuclear factor-KB activation of Kupffer cells （KCs）, liver sinusoidal endothelial cells （LSECs） and hepatic stellate cells （HSCs）, and it subsequently decreased cytokine mRNA expression in KCs and LSECs and reduced the production of TGF-β1 in HSCs. CONCLUSION： A20 might prevent chronic liver allogra- ft dysfunction by re-establishing functional homeostasis of KCs, LSECs and HSCs.展开更多
PrPSc,a misfolded,aggregation-prone isoform of the cellular prion protein(PrPC),is the infectious prion agent responsible for fatal neurodegenerative diseases of humans and other mammals.PrPSccan adopt different patho...PrPSc,a misfolded,aggregation-prone isoform of the cellular prion protein(PrPC),is the infectious prion agent responsible for fatal neurodegenerative diseases of humans and other mammals.PrPSccan adopt different pathogenic conformations(prion strains),which can be resistant to potential drugs,or acquire drug resistance,posing challenges for the development of effective therapies.Since PrPCis the obligate precursor of any prion strain and serves as the mediator of prion neurotoxicity,it represents an attractive therapeutic target fo r prion diseases.In this minireview,we briefly outline the approaches to target PrPCand discuss our recent identification of Zn(Ⅱ)-Bn PyP,a PrPC-targeting porphyrin with an unprecedented bimodal mechanism of action.We argue that in-depth understanding of the molecular mechanism by which Zn(Ⅱ)-Bn PyP targets PrPCmay lead toward the development of a new class of dual mechanism anti-prion compounds.展开更多
文摘Dof(DNA-binding with one finger)蛋白是植物特有的一类转录因子,在植物生长发育过程中起着重要的作用。在其N-末端有一个52氨基酸残基组成的高度保守的C2-C2单锌指结构,称为Dof保守域,能够特异性的识别植物启动子序列中的AAAG/CTTT作用元件,从而激活或抑制植物基因的表达;其C-末端的转录调控结构域,氨基酸序列较为多变,不具有保守性,是Dof蛋白在植物中功能多样性的基础;同时Dof蛋白也具有和蛋白相互作用的功能。在过去的十几年里,大量的Dof基因被克隆鉴定或从基因组数据库中预测出来,Dof蛋白在植物生长发育中的作用也受到更多关注。本文就Dof转录因子的特点,各物种中已经报道的Dof转录因子的数目、系统进化关系和分类及其生物学功能的进展进行了综述。
基金supported by the National Natural Science Foundation of China (30971773)the Natural Science Foundation of Hebei Province,China (C2011204031)the Key Laboratory of Crop Growth Regulation of Hebei Province,China
文摘Based on sequencing of part clones in a root subtractive cDNA library, an expressed sequence tag （EST） sharing high similarity to a rice C2H2 zinc finger transcription factor （ZFP15） was obtained in wheat. Through bioinformatics approach, the wheat C2H2-type ZFP gene referred to TaZFP15 has been identified and characterized. As a full-length cDNA of 670 bp, TaZFP15 has an open reading frame of 408 bp and encodes a 135-aa polypeptide. TaZFP15 contains two C2H2 zinc finger domains and each one has a conserved motif QALGGH. The typical L-box, generally identified in the C2H2 type transcription factors, has also been found in TaZFP15. Phylogenetic analysis suggested that TaZFP15 shares high similarities with rice ZFP15 （GenBank accession no. AY286473）, maize ZFP （GenBank accession no. NM_001159094） and a subset of other zinc-finger transcription factor genes in plant species. The expression of TaZFP15 was up-regulated by starved-Pi stress, showing a pattern to be gradually elevated along with the progression of the Pi-stress in a 23-h treatment regime. Similarly, the transcripts of TaZFP15 in roots were also induced by nitrogen deficiency, and abiotic stresses of drought and salinity. No responses of TaZFP15 were detected in roots to nutrition deficiencies of P, Zn, and Ca, and the external treatment of abscisic acid （ABA）. TaZFP15 could be specifically amplified in genome A, B, and D, and without variability in the sequences, suggesting that TaZFP15 has multi-copies in the homologous hexaploid species. Transgenic analysis in tobacco revealed that up-regulation of TaZFP15 could significantly improve plant dry mass accumulation via increasing the plant phosphorus acquisition capacity under Pi-deficiency condition. The results suggested that TaZFP15 is involved in mediation of signal transductions of diverse external stresses.
基金National Natural Science Foundation of China, No 30200273 & 30672067
文摘AIM： To investigate the role of SMYD3 in hepatocellular carcinoma （HCC） development and progression and to verify whether its regulation activity was through RIZ1 inactivation. METHODS： Expression of SMYD3 in HCC cell lines and tissues were measured; silencing of SMYD3 by RNA interference （RNAi） was effectuated, hepatoma cell proliferation, migration and apoptosis were tested, with RIZl CpG promoter methylation, and corresponding mRNA expression were investigated. RESULTS： SMYD3 over-expression in HCC was associated with RIZl hypermethylation and mRNA down-expression. Suppression of SMYD3 expression de- methylated RIZl CpG promoter （P 〈 0.01） and increased RIZl mRNA expression （P 〈 0.01）. Consequently, SMYD3 down-expression with RIZl de-methylation strongly inhibited hepatoma cell growth （MTT inhibitory rates： Pgenesil-1-s1 60.95%± 7.97%, Pgenesil-1-s2 72.14% ± 9.68% vs Pgenesil-1-hk 6.89% ± 4.12%, P 〈 0.01） and migration （Pgenesil-1-s1 4.24% ± 1.58%, Pgenesil- 1-s1 4.87% ± 0.73% vs Pgenesil-1 19.03% ± 4.63%, Pgenesil-1-hk 19.95% ±5.21%, P 〈 0.01） and induced apoptosis （FCM subG1 phase Pgenesil-1-s1 19.07% ＋ 1.78%, Pgenesil-1-s2 17.68% ± 2.36% vs Pgenesil-1 0.47% ± 0.12%, Pgenesil-1-hk 1.46% ± 0.28%, P 〈 0.01. TUNEL-positive cells： Pgenesil-1-s1 40.24%± 5.18%, Pgenesil-1-s2 38.48% ± 4.65% vs Pgenesil-1 2.1B% - 1.34%, Pgenesil-1-hk 2.84%± 1.22%, P 〈 0.01） in HepG2 cells. CONCLUSION： These results demonstrate that SMYD3plays a critical role in the carcinogenesis and progression of HCC, The proliferation, migration induction and apoptosis inhibition activities of SMYD3 may be mediated through RIZl CpG promoter hypermethylation.
文摘N^6-methyladenosine(m6A),a ubiquitous RNA modification,is installed by METTL3-METTL14 complex.The structure of the heterodimeric complex between the methyltransferase domains(MTDs)of METTL3 and METTL14 has been previously determined.However,the MTDs alone possess no enzymatic activity.Here we present the solution structure for the zinc finger domain(ZFD)of METTL3,the inclusion of which fulfills the methyltransferase activity of METTL3-METTL14.We show that the ZFD specifically binds to an RNA containing 5'-GGACU-3'consensus sequence,but does not to one without.The ZFD thus serves as the target recognition domain,a structural feature previously shown for DNA methyltransferases,and cooperates with the MTDs of METTL3-METTL14 for catalysis.However,the interaction between the ZFD and the specific RNA is extremely weak,with the binding affinity at several hundred micromolar under physiological conditions.The ZFD contains two CCCH-type zinc fingers connected by an anti-parallel P-sheet.Mutational analysis and NMR titrations have mapped the functional interface to a contiguous surface.As a division of labor,the RNA-binding interface comprises basic residues from zinc finger 1 and hydrophobic residues fromβ-sheet and zinc finger 2.Further we show that the linker between the ZFD and MTD of METTL3 is flexible but partially folded,which may permit the cooperation between the two domains during catalysis.Together,the structural characterization of METTL3 ZFD paves the way to elucidate the atomic details of the entire process of RNA m6A modification.
文摘Secondary walls, which represent the bulk of biomass, have a large impact on plant growth and adaptation to environments. Secondary wall synthesis is switched and regulated by a sophisticated signaling transduction network. However, there is limited understanding of these regulatory pathways. Here, we report that ILAl-interacting protein 4 （lIP4） can repress secondary wall synthesis, lIP4 is a phosphorylation sub- strate of an Raf-like MAPKKK, but its function is unknown. By generating lip4 mutants and relevant transgenic plants, we found that lesions in lIP4 enhance secondary wall formation. Gene expression and transactivation activity assays revealed that lIP4 negatively regulates the expression of MYB61 and CESAs but does not bind their promoters, lIP4 interacts with NAC29/NAC31, the upstream regulators of secondary wall synthesis, and suppresses the downstream regulatory pathways in plants. Mutagenesis analyses showed that phosphomimic UP4 proteins translocate from the nucleus to the cytoplasm, which releases interacting NACs and attenuates its repression function. Moreover, we revealed that liPs are evolutionarily conserved and share unreported CCCH motifs, referred to as uncanonical CCCH-tandem zinc-finger proteins. Collectively, our study provides mechanistic insights into the control of secondary wall synthesis and presents an opportunity for improving relevant agronomic traits in crops.
基金Supported by the National Key Technology Research and Development Program (2006BAD03A01)the Hi-Tech Research and Development Program of China (2007AA10Z106)the Key Program Project of Ministry of Education (104242).
文摘The Populus euphratica stress responsive zinc-finger protein gene PSTZ, which encodes a protein including typical Cys2/His2 zinc finger structure, was isolated by reverse transcription-polymerase chain reaction from P. euphratica. Northern hybridization revealed that its expression was induced under drought and salt stress conditions. To examine its function, cDNA of the PSTZ gene, driven by the cauliflower mosaic virus 35S promoter, was cloned into a plant expression vector pBin438 and introduced into tobacco plants. Transgenic tobacco showed an enhanced salt tolerance, suggesting that PSTZ may play a role in plant responsiveness to salt stress.
基金Supported by Hebei Provincial Health Commission Youth Science and Technology Project,No.20210027.
文摘BACKGROUND Colorectal cancer(CRC)is the third most common cancer and a significant cause of cancer-related mortality globally.Resistance to chemotherapy,especially during CRC treatment,leads to reduced effectiveness of drugs and poor patient outcomes.Long noncoding RNAs(lncRNAs)have been implicated in various pathophysiological processes of tumor cells,including chemotherapy resistance,yet the roles of many lncRNAs in CRC remain unclear.AIM To identify and analyze the lncRNAs involved in oxaliplatin resistance in CRC and to understand the underlying molecular mechanisms influencing this resistance.METHODS Gene Expression Omnibus datasets GSE42387 and GSE30011 were reanalyzed to identify lncRNAs and mRNAs associated with oxaliplatin resistance.Various bioinformatics tools were employed to elucidate molecular mechanisms.The expression levels of lncRNAs and mRNAs were assessed via quantitative reverse transcription-polymerase chain reaction.Functional assays,including MTT,wound healing,and Transwell,were conducted to investigate the functional implications of lncRNA alterations.Interactions between lncRNAs and trans-cription factors were examined using RIP and luciferase reporter assays,while Western blotting was used to confirm downstream pathways.Additionally,a xenograft mouse model was utilized to study the in vivo effects of lncRNAs on chemotherapy resistance.RESULTS LncRNA prion protein testis specific(PRNT)was found to be upregulated in oxaliplatin-resistant CRC cell lines and negatively correlated with homeodomain interacting protein kinase 2(HIPK2)expression.PRNT was demonstrated to sponge transcription factor zinc finger protein 184(ZNF184),which in turn could regulate HIPK2 expression.Altered expression of PRNT influenced CRC cell sensitivity to oxaliplatin,with overexpression leading to decreased sensitivity and decreased expression reducing resistance.Both RIP and luciferase reporter assays indicated that ZNF184 and HIPK2 are targets of PRNT.The PRNT/ZNF184/HIPK2 axis was implicated in promoting CRC prog
基金Supported by The National Natural Science Foundation of China,No.30872529the PhD Program Fund of the Ministry of Education of China,No.20030610078the Chinese Postdoctoral Science Foundation,No.2003033531
文摘AIM： To investigate the effect of zinc finger protein A20 on chronic liver allograft dysfunction in rats. METHODS： AIIogeneic liver transplantation from DA rats to Lewis rats was performed. Chronic liver allograft dysfunction was induced in the rats by administering low-dose tacrolimus at postoperative day （POD） 5. Hepatic overexpression of A20 was achieved by recom- binant adenovirus （rAd.）-mediated gene transfer ad- ministered intravenously every 10 d starting from POD 10. The recipient rats were injected with physiologi- cal saline, rAdEasy-A20 （1 × 109 pfu/30 g weight） or rAdEasy （1 × 109 pfu/30 g weight） every 10 d through the tail vein for 3 mo starting from POD 10. Liver tissue samples were harvested on POD 30 and POD 60. RESULTS： Liver-transplanted rats treated with only tacrolimus showed chronic allograft dysfunction with severe hepatic fibrosis. A20 overexpression ameliorated the effects on liver function, attenuated liver allograft fibrosis and prolonged the survival of the recipient rats. Treatment with A20 suppressed hepatic protein pro- duction of tumor growth factor （TGF）-β1, interleukin- 113, caspase-8, CD40, CD40L, intercellular adhesion molecule-i, vascular cell adhesion molecule-1 and E-selectin. A20 treatment suppressed liver cell apopto- sis and inhibited nuclear factor-KB activation of Kupffer cells （KCs）, liver sinusoidal endothelial cells （LSECs） and hepatic stellate cells （HSCs）, and it subsequently decreased cytokine mRNA expression in KCs and LSECs and reduced the production of TGF-β1 in HSCs. CONCLUSION： A20 might prevent chronic liver allogra- ft dysfunction by re-establishing functional homeostasis of KCs, LSECs and HSCs.
基金supported by Telethon Italy award GGP15225(to RC and GM)Italian Ministry of Health award RF-2016-02362950(to RC and CZ)+1 种基金the CJD Foundation USA(to RC)the Associazione Italiana Encefalopatie da Prioni(AIEnP)(to RC).
文摘PrPSc,a misfolded,aggregation-prone isoform of the cellular prion protein(PrPC),is the infectious prion agent responsible for fatal neurodegenerative diseases of humans and other mammals.PrPSccan adopt different pathogenic conformations(prion strains),which can be resistant to potential drugs,or acquire drug resistance,posing challenges for the development of effective therapies.Since PrPCis the obligate precursor of any prion strain and serves as the mediator of prion neurotoxicity,it represents an attractive therapeutic target fo r prion diseases.In this minireview,we briefly outline the approaches to target PrPCand discuss our recent identification of Zn(Ⅱ)-Bn PyP,a PrPC-targeting porphyrin with an unprecedented bimodal mechanism of action.We argue that in-depth understanding of the molecular mechanism by which Zn(Ⅱ)-Bn PyP targets PrPCmay lead toward the development of a new class of dual mechanism anti-prion compounds.
