Treatment of Mycobacterium abscessus(Mab)infections is very challenging due to its intrinsic resistance to most available drugs.Therefore,it is crucial to discover novel anti-Mab drugs.In this study,we explored an int...Treatment of Mycobacterium abscessus(Mab)infections is very challenging due to its intrinsic resistance to most available drugs.Therefore,it is crucial to discover novel anti-Mab drugs.In this study,we explored an intrinsic resistance mechanism through which Mab resists echinomycin(ECH).ECH showed activity against Mab at a minimum inhibitory concentration(MIC)of 2μg/ml.A embC strain in which the embC gene was knocked out showed hypersensitivity to ECH(MIC:0.0078-0.0156μg/ml).The MICs of ECH-resistant strains screened with reference to AembC ranged from 0.25 to 1μg/ml.Mutations in EmbB,including D306A,D306N,R350G,V555l,and G581S,increased the Mab's resistance to ECH when overexpressed in AembC individually(MIC:0.25-0.5μg/ml).These EmbB mutants,edited using the CRISPR/Cpf1 system,showed heightened resistance to ECH(MIC:0.25-0.5μg/ml).The permeability of these Mab strains with edited genes and overexpression was reduced,as evidenced by an ethidium bromide accumulation assay,but it remained significantly higher than that of the parent Mab.In summary,our study demonstrates that ECH exerts potent anti-Mab activity and confirms that EmbB and EmbC are implicated in Mab's sensitivity to ECH.Mutation in EmbB may partially compensate foralossof EmbCfunction.展开更多
Objective:To evaluate whether hypoxia inducible factor(HIF-1α) targeting pharmacological drugs,echinomycin,resveratrol and CdCl_2 which inhibit HIF-1α stimulation,and mimosine,which enhances the stability of HIF-1α...Objective:To evaluate whether hypoxia inducible factor(HIF-1α) targeting pharmacological drugs,echinomycin,resveratrol and CdCl_2 which inhibit HIF-1α stimulation,and mimosine,which enhances the stability of HIF-1α present antileishmanial properties.Methods:The leishmanicidal effect of drugs was evaluated in mouse macrophages and Balb/c mouse model for cutaneous leishmaniosis.Results:Resveratrol and CdCl_2 reduced the parasite load [IC50,(27.3±2.25) μM and(24.8±0.95) μM,respectively].The IC50 value of echinomycin was(22.7±7.36) nM and mimosine did not alter the parasite load in primary macrophages.The macrophage viability IC50 values for resveratrol,echinomycin and CdCl_2 and mimosine were >40 μM,>100 nM,> 200 μM and>2 000 μM,respectively.In vivo no differences between cutaneous lesions from control,resveratrol-and echinomycin-treated Balb/c mice were detected.Conclusions:Resveratrol,echinomycin and CdCl_2 reduce parasite survival in vitro.The HIF-1α targeting pharmacological drugs require further study to more fully determine their anti-Leishmania potential and their role in therapeutic strategies.展开更多
基金This work was supported by the National Key R&D Program of China(2021YFA1300900)the National Natural Science Foundation of China(21920102003,82022067,and 22037006)+5 种基金the Chinese Academy of Sciences Grants(154144KYSB20190005 and YJKYYQ20210026)the Key R&D Program of Sichuan Provenience(2023YFSY0047)the State Key Laboratory of Respiratory Disease,Guangzhou Institute of Respiratory Diseases,First Affiliated Hospital of Guangzhou Medical University(SKLRD-Z-202414,SKLRD-OP-202324,SKLRD-Z-202301,SKLRD-OP-202113,and SKLRD-Z-202412)Guangzhou Scienceaand Technology Plan-Youth Doctoral"Sail"Project(2024A04J4273)President's International Fellowship Initiative-CAS(2023VBC0015)the National Foreign Young Talent Program(QN2022031002L).
文摘Treatment of Mycobacterium abscessus(Mab)infections is very challenging due to its intrinsic resistance to most available drugs.Therefore,it is crucial to discover novel anti-Mab drugs.In this study,we explored an intrinsic resistance mechanism through which Mab resists echinomycin(ECH).ECH showed activity against Mab at a minimum inhibitory concentration(MIC)of 2μg/ml.A embC strain in which the embC gene was knocked out showed hypersensitivity to ECH(MIC:0.0078-0.0156μg/ml).The MICs of ECH-resistant strains screened with reference to AembC ranged from 0.25 to 1μg/ml.Mutations in EmbB,including D306A,D306N,R350G,V555l,and G581S,increased the Mab's resistance to ECH when overexpressed in AembC individually(MIC:0.25-0.5μg/ml).These EmbB mutants,edited using the CRISPR/Cpf1 system,showed heightened resistance to ECH(MIC:0.25-0.5μg/ml).The permeability of these Mab strains with edited genes and overexpression was reduced,as evidenced by an ethidium bromide accumulation assay,but it remained significantly higher than that of the parent Mab.In summary,our study demonstrates that ECH exerts potent anti-Mab activity and confirms that EmbB and EmbC are implicated in Mab's sensitivity to ECH.Mutation in EmbB may partially compensate foralossof EmbCfunction.
基金supported by Fundacao de Amparo a Pesquisa do Estado de Sao Paulo,Conselho Nacional de Desenvolvimento Científico e Tecnologico (NO.2009/10771-9)Coordenacao de Aperfeicoamento de Pessoal de Nível Superior (NO.301052/2009-3),Brazil
文摘Objective:To evaluate whether hypoxia inducible factor(HIF-1α) targeting pharmacological drugs,echinomycin,resveratrol and CdCl_2 which inhibit HIF-1α stimulation,and mimosine,which enhances the stability of HIF-1α present antileishmanial properties.Methods:The leishmanicidal effect of drugs was evaluated in mouse macrophages and Balb/c mouse model for cutaneous leishmaniosis.Results:Resveratrol and CdCl_2 reduced the parasite load [IC50,(27.3±2.25) μM and(24.8±0.95) μM,respectively].The IC50 value of echinomycin was(22.7±7.36) nM and mimosine did not alter the parasite load in primary macrophages.The macrophage viability IC50 values for resveratrol,echinomycin and CdCl_2 and mimosine were >40 μM,>100 nM,> 200 μM and>2 000 μM,respectively.In vivo no differences between cutaneous lesions from control,resveratrol-and echinomycin-treated Balb/c mice were detected.Conclusions:Resveratrol,echinomycin and CdCl_2 reduce parasite survival in vitro.The HIF-1α targeting pharmacological drugs require further study to more fully determine their anti-Leishmania potential and their role in therapeutic strategies.
