Restoration of kidney tubular epithelium following sublethal injury sequentially involves partial epithelial–mesenchymal transition(pEMT),proliferation,and further redifferentiation into specialized tubule epithelial...Restoration of kidney tubular epithelium following sublethal injury sequentially involves partial epithelial–mesenchymal transition(pEMT),proliferation,and further redifferentiation into specialized tubule epithelial cells(TECs).Because the immunosuppressant cyclosporine-A produces pEMT in TECs and inhibits the peptidyl-prolyl isomerase(PPIase)activity of cyclophilin(Cyp)proteins,we hypothesized that cyclophilins could regulate TEC phenotype.Here we demonstrate that in cultured TECs,CypA silencing triggers loss of epithelial features and enhances transforming growth factorβ(TGFβ)-induced EMT in association with upregulation of epithelial repressors Slug and Snail.This pro-epithelial action of CypA relies on its PPIase activity.By contrast,CypB emerges as an epithelial repressor,because CypB silencing promotes epithelial differentiation,prevents TGFβ-induced EMT,and induces tubular structures in 3D cultures.In addition,in the kidneys of CypB knockout mice subjected to unilateral ureteral obstruction,inflammatory and pro-fibrotic events were attenuated.CypB silencing/knockout leads to Slug,but not Snail,downregulation.CypB support of Slug expression depends on its endoplasmic reticulum location,where it interacts with calreticulin,a calcium-buffering chaperone related to Slug expression.As CypB silencing reduces ionomycin-induced calcium release and Slug upregulation,we suggest that Slug expression may rely on CypB modulation of calreticulin-dependent calcium signaling.In conclusion,this work uncovers new roles for CypA and CypB in modulating TEC plasticity and identifies CypB as a druggable target potentially relevant in promoting kidney repair.展开更多
Reverse_transcription Polymerase Chain Reaction (RT_PCR) was performed using cDNAs as templates from wheat_ Haynaldia villosa 6VS/6AL translocation line and 'Yangmai 5' induced with fungus Erysiphe gramin...Reverse_transcription Polymerase Chain Reaction (RT_PCR) was performed using cDNAs as templates from wheat_ Haynaldia villosa 6VS/6AL translocation line and 'Yangmai 5' induced with fungus Erysiphe graminis , and degenerate primers designed based on the conserved amino acid sequences of known plant disease_resistance genes. The cDNA sequences encoding cyclophilin_like and H +_ATPase_like genes were first isolated and characterized in wheat. The putative amino acid sequences of the two clones showed that they were highly homologous to those of cyclophilin proteins and H +_ATPases isolated from other plants. Thus they were designated as Ta_Cyp and Ta_MAH . The obvious expression differences could be observed between wheat_ H. villosa 6VS/6AL translocation line and susceptible wheat cultivar 'Yangmai 5', implying that the two genes may be related with the resistance of wheat_ H. villosa 6VS/6AL translocation line to disease. Southern blot indicated that the wheat genome contained 2-3 copies of Ta_Cyp gene and one copy of the Ta_MAH gene. Chinese Spring nulli_tetrasomic line analysis located the Ta_Cyp homologous genes on wheat chromosome 6A, 6B and 6D. Southern blot using Ta_Cyp clone as a probe showed that the polymorphic bands existed among the H. villosa , amphiploid of Triticum durum _ H. villosa , wheat_ H. villosa 6VS/6AL translocation line and 'Yangmai 5', suggesting that Ta_Cyp homologies exist in wheat genome as well as on the short arm of chromosome 6V in H. villosa .展开更多
A cDNA clone encoded for cyclophilin (GmCyp1) was isolated by RT-PCR method from suspension-cultured soybean (Glycine max L.) cells. The deduced amino acid sequence was 91% identical to a kidney bean cyclophilin in t...A cDNA clone encoded for cyclophilin (GmCyp1) was isolated by RT-PCR method from suspension-cultured soybean (Glycine max L.) cells. The deduced amino acid sequence was 91% identical to a kidney bean cyclophilin in the open reading frame of the gene. Results from Southern blotting analysis suggests that the GmCyp1 belong to a small gene family in soybean cells. The time course of GmCyp1 mRNA accumulation upon treatment of elicitor from yeast extract did not show significant change in the time period examined. The data suggest that the GmCyp1 was not regulated much by biotic factors. A possible role of the cyclophilin in the plant-pathogen interaction was discussed.展开更多
p53＇s apoptotic program consists of transcription-dependent and transcription-independent pathways. In the latter, physical interactions between mitochondrial p53 and anti- and pro-apoptotic members of the Bcl2 famil...p53＇s apoptotic program consists of transcription-dependent and transcription-independent pathways. In the latter, physical interactions between mitochondrial p53 and anti- and pro-apoptotic members of the Bcl2 family of mitochondrial permeability regulators are central. Using isogenic cell systems with defined deficiencies, we characterize in detail how mitochondrial p53 contributes to mitochondrial permeabilization, to what extent its action depends on other key Bcl2 family members and define its release activity. We show that mitochondrial p53 is highly efficient in inducing the release of soluble and insoluble apoptogenic factors by severely disrupting outer and inner mitochondrial membrane integrity. This action is associated with wild-type p53-induced oligomerization of Bax, Bak and VDAC and the formation of a stress-induced endogenous complex between p53 and cyclophilin D, normally located at the inner membrane. Tumor-derived p53 mutants are deficient in activating the Bax/Bak lipid pore. These actions are independent of Puma and Bax. Importantly, the latter distinguishes the mitochondrial from the cytosolic p53 death pathway.展开更多
Until recently the traditional treatment for hepatitis C infection included pegylated interferon and ribavirin combination therapy.The sustained virological response(SVR)seen with this combination is poor and requires...Until recently the traditional treatment for hepatitis C infection included pegylated interferon and ribavirin combination therapy.The sustained virological response(SVR)seen with this combination is poor and requires lengthy treatment to achieve.Additionally,significant side effects and numerous contraindications prevented many patients from being successfully treated with this therapy.In 2011,two new protease inhibitors,telaprevir and boceprevir,were approved for use with pegylated interferon and ribavirin in the United States by the United States Food and Drug Administration.These agents have significantly improved SVR rates;however significant problems with toxicity remain including severe skin rash and neutropenia.There are a wide range of compounds in late stage development for the future treatment of hepatitis C that exploit many different mechanisms of viral inhibition.Some of these compounds include additional protease inhibitors,like telaprevir and boceprevir,as well as inhibitors of other nonstructural proteins in the viral genome such as NS5A and NS5B,and compounds that target host proteins within the virus.Some of these agents are being developed for oral administration once daily and various combinations are being assessed for use without the need for pegylated interferon and ribavirin.This paper reviews agents in late phase development that may be commercially available within 1-2 years.展开更多
OBJECTIVE To explored the potential of pharmacological stabilization and reactivation of p53 for targeted cancer therapies.METHODS The cytotoxicity of a potent Cyclophilin A(CypA)inhibitor HL001 was tasted against a p...OBJECTIVE To explored the potential of pharmacological stabilization and reactivation of p53 for targeted cancer therapies.METHODS The cytotoxicity of a potent Cyclophilin A(CypA)inhibitor HL001 was tasted against a panel of cancer cell lines.The genotypes and activation of p53 were compared with the cytotoxicity profile of HL001.Two-dimensional(2D)PAGE analysis was performed to investigate differentially expressed proteins that involves in the anti-proliferation effects of HL001.Pull-down and Co-IP were used to confirmed the new identified PPI between CypA and G3BP1 and orthotopic animal model of lung cancer was used to tested the anti-tumor activity of HL001 in vivo.RESULTS We identify a novel CypA small molecule inhibitor HL001 that induces non-small cell lung cancer(NSCLC)cell cycle arrest and apoptosis via restoring p53 expression.We find that HL001 stabilizes p53 through inhibiting the MDM2-mediated p53 ubiquitination.Further mechanistic studies reveal that the downregulation of G3BP1 and the induction of reactive oxygen species and DNA damage by HL001 contribute to p53 stabilization.Surprisingly,HL001 selectively suppresses tumor growth in p53wildtype NSCLC harboring Arg72 homozygous alleles(p53-72R)through disrupting interaction between MDM2 and p53-72R in a CypA dependent manner.Moreover,combining HL001 with cisplatin synergistically enhance tumor regression in orthotopic NSCLC mouse model.CONCLUSION Pharmacologic inhibition of CypA offers a potential therapeutic strategy via specific activation of p53-72R in NSCLC.展开更多
Hepatitis C virus （HCV） infection affects 180 million people worldwide with the predominant prevalence being infection with genotype 1, followed by genotypes 2 and 3. Standard anti-HCV therapy currently aims to enha...Hepatitis C virus （HCV） infection affects 180 million people worldwide with the predominant prevalence being infection with genotype 1, followed by genotypes 2 and 3. Standard anti-HCV therapy currently aims to enhance natural immune responses to the virus, whereas new therapeutic concepts directly target HCV RNA and viral enzymes or influence host-virus interactions. Novel treatment options now in development are focused on inhibitors of HCV- specific enzymes, NS3 protease and NS5B polymerase. These agents acting in concert represent the concept of specifically targeted antiviral therapy for HCV （STAT-C）. STAT-C is an attractive strategy in which the main goal is to increase the effectiveness of antiviral responses across all genotypes, with shorter treatment duration and better tolerability. However, the emergence of resistant mutations that limit the use of these compounds in monotherapy complicates the regimens. Thus, a predictable scenario for HCV treatment in the future will be combinations of drugs with distinct mechanisms of action. For now, it seems that interferon will remain a fundamental component of any new anti-HCV therapeutic regimens in the near future; therefore, there is pressure to develop forms of interferon that are more effective, less toxic, and more convenient than pegylated interferon.展开更多
Over 170 million people worldwide are infected with hepatitis C virus (HCV), a major cause of liver diseases. Current interferon-based therapy is of limited efficacy and has significant side effects and more effective...Over 170 million people worldwide are infected with hepatitis C virus (HCV), a major cause of liver diseases. Current interferon-based therapy is of limited efficacy and has significant side effects and more effective and better tolerated therapies are urgently needed. HCV is a positive, single-stranded RNA virus with a 9.6 kb genome that encodes ten viral proteins. Among them, the NS3 protease and the NS5B polymerase are essential for viral replication and have been the main focus of drug discovery efforts. Aided by structure-based drug design, potent and specific inhibitors of NS3 and NS5B have been identified, some of which are in late stage clinical trials and may significantly improve current HCV treatment. Inhibitors of other viral targets such as NS5A are also being pursued. However, HCV is an RNA virus characterized by high replication and mutation rates and consequently, resistance emerges quickly in patients treated with specific antivirals as monotherapy. A complementary approach is to target host factors such as cyclophilins that are also essential for viral replication and may present a higher genetic barrier to resistance. Combinations of these inhibitors of different mechanism are likely to become the essential components of future HCV therapies in order to maximize antiviral efficacy and prevent the emergence of resistance.展开更多
基金supported in part by grants from Ministerio de Cienciae Innovacion(SAF 201459945-Rand SAF 201789989-R to A.M.)the Fundacion Senefro(SEN 2019 to A.M.),Instituto de Salud Carloslll(PIE13/00027)Red de Investigacion Renal REDinREN(12/0021/0013).KAN.is supported by Nationa Mnstitutes of Health(NIH)DK 47060.A.M.group holds the Quality Mention from the Generalitat de Catalunya(2017 SGR).
文摘Restoration of kidney tubular epithelium following sublethal injury sequentially involves partial epithelial–mesenchymal transition(pEMT),proliferation,and further redifferentiation into specialized tubule epithelial cells(TECs).Because the immunosuppressant cyclosporine-A produces pEMT in TECs and inhibits the peptidyl-prolyl isomerase(PPIase)activity of cyclophilin(Cyp)proteins,we hypothesized that cyclophilins could regulate TEC phenotype.Here we demonstrate that in cultured TECs,CypA silencing triggers loss of epithelial features and enhances transforming growth factorβ(TGFβ)-induced EMT in association with upregulation of epithelial repressors Slug and Snail.This pro-epithelial action of CypA relies on its PPIase activity.By contrast,CypB emerges as an epithelial repressor,because CypB silencing promotes epithelial differentiation,prevents TGFβ-induced EMT,and induces tubular structures in 3D cultures.In addition,in the kidneys of CypB knockout mice subjected to unilateral ureteral obstruction,inflammatory and pro-fibrotic events were attenuated.CypB silencing/knockout leads to Slug,but not Snail,downregulation.CypB support of Slug expression depends on its endoplasmic reticulum location,where it interacts with calreticulin,a calcium-buffering chaperone related to Slug expression.As CypB silencing reduces ionomycin-induced calcium release and Slug upregulation,we suggest that Slug expression may rely on CypB modulation of calreticulin-dependent calcium signaling.In conclusion,this work uncovers new roles for CypA and CypB in modulating TEC plasticity and identifies CypB as a druggable target potentially relevant in promoting kidney repair.
文摘Reverse_transcription Polymerase Chain Reaction (RT_PCR) was performed using cDNAs as templates from wheat_ Haynaldia villosa 6VS/6AL translocation line and 'Yangmai 5' induced with fungus Erysiphe graminis , and degenerate primers designed based on the conserved amino acid sequences of known plant disease_resistance genes. The cDNA sequences encoding cyclophilin_like and H +_ATPase_like genes were first isolated and characterized in wheat. The putative amino acid sequences of the two clones showed that they were highly homologous to those of cyclophilin proteins and H +_ATPases isolated from other plants. Thus they were designated as Ta_Cyp and Ta_MAH . The obvious expression differences could be observed between wheat_ H. villosa 6VS/6AL translocation line and susceptible wheat cultivar 'Yangmai 5', implying that the two genes may be related with the resistance of wheat_ H. villosa 6VS/6AL translocation line to disease. Southern blot indicated that the wheat genome contained 2-3 copies of Ta_Cyp gene and one copy of the Ta_MAH gene. Chinese Spring nulli_tetrasomic line analysis located the Ta_Cyp homologous genes on wheat chromosome 6A, 6B and 6D. Southern blot using Ta_Cyp clone as a probe showed that the polymorphic bands existed among the H. villosa , amphiploid of Triticum durum _ H. villosa , wheat_ H. villosa 6VS/6AL translocation line and 'Yangmai 5', suggesting that Ta_Cyp homologies exist in wheat genome as well as on the short arm of chromosome 6V in H. villosa .
文摘A cDNA clone encoded for cyclophilin (GmCyp1) was isolated by RT-PCR method from suspension-cultured soybean (Glycine max L.) cells. The deduced amino acid sequence was 91% identical to a kidney bean cyclophilin in the open reading frame of the gene. Results from Southern blotting analysis suggests that the GmCyp1 belong to a small gene family in soybean cells. The time course of GmCyp1 mRNA accumulation upon treatment of elicitor from yeast extract did not show significant change in the time period examined. The data suggest that the GmCyp1 was not regulated much by biotic factors. A possible role of the cyclophilin in the plant-pathogen interaction was discussed.
文摘p53＇s apoptotic program consists of transcription-dependent and transcription-independent pathways. In the latter, physical interactions between mitochondrial p53 and anti- and pro-apoptotic members of the Bcl2 family of mitochondrial permeability regulators are central. Using isogenic cell systems with defined deficiencies, we characterize in detail how mitochondrial p53 contributes to mitochondrial permeabilization, to what extent its action depends on other key Bcl2 family members and define its release activity. We show that mitochondrial p53 is highly efficient in inducing the release of soluble and insoluble apoptogenic factors by severely disrupting outer and inner mitochondrial membrane integrity. This action is associated with wild-type p53-induced oligomerization of Bax, Bak and VDAC and the formation of a stress-induced endogenous complex between p53 and cyclophilin D, normally located at the inner membrane. Tumor-derived p53 mutants are deficient in activating the Bax/Bak lipid pore. These actions are independent of Puma and Bax. Importantly, the latter distinguishes the mitochondrial from the cytosolic p53 death pathway.
文摘Until recently the traditional treatment for hepatitis C infection included pegylated interferon and ribavirin combination therapy.The sustained virological response(SVR)seen with this combination is poor and requires lengthy treatment to achieve.Additionally,significant side effects and numerous contraindications prevented many patients from being successfully treated with this therapy.In 2011,two new protease inhibitors,telaprevir and boceprevir,were approved for use with pegylated interferon and ribavirin in the United States by the United States Food and Drug Administration.These agents have significantly improved SVR rates;however significant problems with toxicity remain including severe skin rash and neutropenia.There are a wide range of compounds in late stage development for the future treatment of hepatitis C that exploit many different mechanisms of viral inhibition.Some of these compounds include additional protease inhibitors,like telaprevir and boceprevir,as well as inhibitors of other nonstructural proteins in the viral genome such as NS5A and NS5B,and compounds that target host proteins within the virus.Some of these agents are being developed for oral administration once daily and various combinations are being assessed for use without the need for pegylated interferon and ribavirin.This paper reviews agents in late phase development that may be commercially available within 1-2 years.
基金supported by National Natural Science Foundation of China(31371485,81402482,91313303 and 81573020)CAS Key Laboratory of Receptor Research,the Shanghai Committee of Science and Technology(15431902000)
文摘OBJECTIVE To explored the potential of pharmacological stabilization and reactivation of p53 for targeted cancer therapies.METHODS The cytotoxicity of a potent Cyclophilin A(CypA)inhibitor HL001 was tasted against a panel of cancer cell lines.The genotypes and activation of p53 were compared with the cytotoxicity profile of HL001.Two-dimensional(2D)PAGE analysis was performed to investigate differentially expressed proteins that involves in the anti-proliferation effects of HL001.Pull-down and Co-IP were used to confirmed the new identified PPI between CypA and G3BP1 and orthotopic animal model of lung cancer was used to tested the anti-tumor activity of HL001 in vivo.RESULTS We identify a novel CypA small molecule inhibitor HL001 that induces non-small cell lung cancer(NSCLC)cell cycle arrest and apoptosis via restoring p53 expression.We find that HL001 stabilizes p53 through inhibiting the MDM2-mediated p53 ubiquitination.Further mechanistic studies reveal that the downregulation of G3BP1 and the induction of reactive oxygen species and DNA damage by HL001 contribute to p53 stabilization.Surprisingly,HL001 selectively suppresses tumor growth in p53wildtype NSCLC harboring Arg72 homozygous alleles(p53-72R)through disrupting interaction between MDM2 and p53-72R in a CypA dependent manner.Moreover,combining HL001 with cisplatin synergistically enhance tumor regression in orthotopic NSCLC mouse model.CONCLUSION Pharmacologic inhibition of CypA offers a potential therapeutic strategy via specific activation of p53-72R in NSCLC.
文摘Hepatitis C virus （HCV） infection affects 180 million people worldwide with the predominant prevalence being infection with genotype 1, followed by genotypes 2 and 3. Standard anti-HCV therapy currently aims to enhance natural immune responses to the virus, whereas new therapeutic concepts directly target HCV RNA and viral enzymes or influence host-virus interactions. Novel treatment options now in development are focused on inhibitors of HCV- specific enzymes, NS3 protease and NS5B polymerase. These agents acting in concert represent the concept of specifically targeted antiviral therapy for HCV （STAT-C）. STAT-C is an attractive strategy in which the main goal is to increase the effectiveness of antiviral responses across all genotypes, with shorter treatment duration and better tolerability. However, the emergence of resistant mutations that limit the use of these compounds in monotherapy complicates the regimens. Thus, a predictable scenario for HCV treatment in the future will be combinations of drugs with distinct mechanisms of action. For now, it seems that interferon will remain a fundamental component of any new anti-HCV therapeutic regimens in the near future; therefore, there is pressure to develop forms of interferon that are more effective, less toxic, and more convenient than pegylated interferon.
文摘Over 170 million people worldwide are infected with hepatitis C virus (HCV), a major cause of liver diseases. Current interferon-based therapy is of limited efficacy and has significant side effects and more effective and better tolerated therapies are urgently needed. HCV is a positive, single-stranded RNA virus with a 9.6 kb genome that encodes ten viral proteins. Among them, the NS3 protease and the NS5B polymerase are essential for viral replication and have been the main focus of drug discovery efforts. Aided by structure-based drug design, potent and specific inhibitors of NS3 and NS5B have been identified, some of which are in late stage clinical trials and may significantly improve current HCV treatment. Inhibitors of other viral targets such as NS5A are also being pursued. However, HCV is an RNA virus characterized by high replication and mutation rates and consequently, resistance emerges quickly in patients treated with specific antivirals as monotherapy. A complementary approach is to target host factors such as cyclophilins that are also essential for viral replication and may present a higher genetic barrier to resistance. Combinations of these inhibitors of different mechanism are likely to become the essential components of future HCV therapies in order to maximize antiviral efficacy and prevent the emergence of resistance.
