Inositol-1-phosphate synthetase mRNA as a new target for antisense inhibition of Mycobacterium tuberculosis.
The need for novel antimicrobial agents to combat the emergence of multi-drug-resistant strains of Mycobacterium tuberculosis is a worldwide urgency. This study has investigated the effects on phosphorothioate-modified antisense oligodeoxyribonucleotides (PS-ODNs) against the mRNA of inositol-1-phosphate synthase, the key enzyme in the first step in inositol synthesis. Inositol is utilized by M. tuberculosis in the production of its major thiol, which is an antioxidant that helps M. tuberculosis to get rid of reactive oxygen species and electrophilic toxins. Real-time RT-PCR analysis revealed that mRNA expression of inositol-1-phosphate (I-1-P) synthase was significantly reduced upon addition of 20 microM PS-ODNs. Treatment with antisense PS-ODNs also reduced the level of mycothiol and the proliferation of M. tuberculosis and enhanced susceptibility to antibiotics. The experiments indicated that the antisense PS-ODNs could enter the cytoplasm of M. tuberculosis and inhibit the expression of I-1-P synthase. This study demonstrates that the M. tuberculosis I-1-P synthase is a target for the development of novel antibiotics and PS-ODN to I-1-P synthase is a promising antimycobaterial candidate.
Li
Yuanyuan
Y
MOE Key Laboratory, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.
Chen
Zhifei
Z
Li
Xiaobo
X
Zhang
Hongling
H
Huang
Qiang
Q
Zhang
Ying
Y
Xu
Shunqing
S
D000900:Anti-Bacterial Agents / Q000494:pharmacology; D015169:Colony Count, Microbial; D003545:Cysteine / Q000378:metabolism; D006020:Glycopeptides / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000494:pharmacology; D007294:Inositol / Q000378:metabolism; D008826:Microbial Sensitivity Tests; D009169:Mycobacterium tuberculosis / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D007296:Myo-Inositol-1-Phosphate Synthase / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D016376:Oligonucleotides, Antisense / Q000494:pharmacology*; D016877:Oxidants / Q000494:pharmacology; D012333:RNA, Messenger / Q000032:analysis / Q000378:metabolism; D013873:Thionucleotides / Q000494:pharmacology
D000900:Anti-Bacterial Agents; D006020:Glycopeptides; D016376:Oligonucleotides, Antisense; D016877:Oxidants; D012333:RNA, Messenger; D013873:Thionucleotides; C089265:mycothiol; D007294:Inositol; D006861:Hydrogen Peroxide; D007296:Myo-Inositol-1-Phosphate Synthase; D003545:Cysteine