title: DNAzymes targeting the icl gene inhibit ICL expression and decrease Mycobacterium tuberculosis survival in macrophages.
abstract: Latent infection with Mycobacterium tuberculosis presents a big obstacle for tuberculosis therapy. In this study, we investigated the effects of sequence-specific DNAzymes targeting the mRNA of isocitrate lyase (ICL), an enzyme playing a pivotal role in the metabolism of M. tuberculosis in the latent state, on the expression of ICL and survival of M. tuberculosis. In vitro studies showed that four of five designed DNAzymes, DZ1, DZ3, DZ4, and DZ5 could cleave icl mRNA efficiently and specifically. Treatment of virulent M. tuberculosis with 5microM DZ4 plus a subinhibitory concentration of isoniazid (INH) decreased ICL expression and the survival of M. tuberculosis in macrophages but had no obvious influence on the growth of M. tuberculosis in vitro. This study demonstrates that using INH to soften the cell wall of M. tuberculosis and help the entry of biomolecules is an efficient method of improving the uptake of DNAzymes. Silencing the icl gene by DNAzyme is a promising method to combat latent infection of tuberculosis.
authors.affiliation: Department of Microbiology and Immunology, Chongqing University of Medical Sciences, 1 Yixueyuan Road, Yuzhong District, Chongqing 400016, China. lisir361@163.com
authors.forename: Junming
authors.initials: J
authors.lastname: Li
authors.forename: Daoyin
authors.initials: D
authors.lastname: Zhu
authors.forename: Zhengjun
authors.initials: Z
authors.lastname: Yi
authors.forename: Yongli
authors.initials: Y
authors.lastname: He
authors.forename: Yang
authors.initials: Y
authors.lastname: Chun
authors.forename: Yehua
authors.initials: Y
authors.lastname: Liu
authors.forename: Na
authors.initials: N
authors.lastname: Li
mesh_terms: D000995:Antitubercular Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism*; D002478:Cells, Cultured; D021881:DNA, Catalytic / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology*; D004797:Enzyme-Linked Immunosorbent Assay; D007522:Isocitrate Lyase / Q000235:genetics* / Q000378:metabolism*; D007538:Isoniazid / Q000494:pharmacology; D008264:Macrophages / Q000382:microbiology*; D009169:Mycobacterium tuberculosis / Q000187:drug effects* / Q000201:enzymology / Q000472:pathogenicity*; D012333:RNA, Messenger / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D013379:Substrate Specificity; D014158:Transcription, Genetic; D014774:Virulence / Q000235:genetics
chemical_list: D000995:Antitubercular Agents; D001426:Bacterial Proteins; D021881:DNA, Catalytic; D012333:RNA, Messenger; C402427:icl protein, Mycobacterium; D007522:Isocitrate Lyase; D007538:Isoniazid