title: Inhibiting the growth of methicillin-resistant Staphylococcus aureus in vitro with antisense peptide nucleic acid conjugates targeting the ftsZ gene.
abstract: BACKGROUND
  The increasing emergence of clinical infections caused by methicillin-resistant Staphylococcus aureus (MRSA) challenges existing therapeutic options and highlights the need to develop novel treatment strategies. The ftsZ gene is essential to bacterial cell division.
  
  
  METHODS
  In this study, two antisense peptide nucleic acids (PNAs) conjugated to a cell-penetrating peptide were used to inhibit the growth of MRSA. PPNA1, identified with computational prediction and dot-blot hybridization, is complementary to nucleotides 309-323 of the ftsZ mRNA. PPNA2 was designed to target the region that includes the translation initiation site and the ribosomal-binding site (Shine-Dalgarno sequence) of the ftsZ gene. Scrambled PPNA was constructed with mismatches to three bases within the antisense PPNA1 sequence.
  
  
  RESULTS
  PPNA1 and PPNA2 caused concentration-dependent growth inhibition and had bactericidal effects. The minimal bactericidal concentrations of antisense PPNA1 and PPNA2 were 30μmol/l and 40μmol/l, respectively. The scrambled PPNA had no effect on bacterial growth, even at higher concentrations, confirming the sequence specificity of the probes. RT-PCR showed that the antisense PPNAs suppressed ftsZ mRNA expression in a dose-dependent manner.
  
  
  CONCLUSIONS
  Our results demonstrate that the potent effects of PNAs on bacterial growth and cell viability were mediated by the down-regulation or even knock-out of ftsZ gene expression. This highlights the utility of ftsZ as a promising target for the development of new antisense antibacterial agents to treat MRSA infections.
authors.affiliation: Department of Clinical Laboratory, the First Affiliated Hospital of Chongqing Medical University, 1 You Yi Road, Yuzhong District, Chongqing 40016, China.
authors.forename: Shumei
authors.initials: S
authors.lastname: Liang
authors.affiliation: Department of Clinical Laboratory, Chongqing Zhongshan Hospital, Chongqing, China.
authors.forename: Yunyan
authors.initials: Y
authors.lastname: He
authors.affiliation: Department of Clinical Laboratory, the First Affiliated Hospital of Chongqing Medical University, 1 You Yi Road, Yuzhong District, Chongqing 40016, China. Electronic address: xiayun12cn@aliyun.com.
authors.forename: Yun
authors.initials: Y
authors.lastname: Xia
authors.affiliation: Department of Clinical Laboratory, the First Affiliated Hospital of Chongqing Medical University, 1 You Yi Road, Yuzhong District, Chongqing 40016, China.
authors.forename: Huijuan
authors.initials: H
authors.lastname: Wang
authors.affiliation: Department of Clinical Laboratory, the First Affiliated Hospital of Chongqing Medical University, 1 You Yi Road, Yuzhong District, Chongqing 40016, China.
authors.forename: Lipeng
authors.initials: L
authors.lastname: Wang
authors.affiliation: Department of Clinical Laboratory, the First Affiliated Hospital of Chongqing Medical University, 1 You Yi Road, Yuzhong District, Chongqing 40016, China.
authors.forename: Rui
authors.initials: R
authors.lastname: Gao
authors.affiliation: Department of Clinical Laboratory, the First Affiliated Hospital of Chongqing Medical University, 1 You Yi Road, Yuzhong District, Chongqing 40016, China.
authors.forename: Meilan
authors.initials: M
authors.lastname: Zhang
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D057846:Cell-Penetrating Peptides; D003598:Cytoskeletal Proteins / Q000235:genetics* / Q000378:metabolism; D015536:Down-Regulation; D015870:Gene Expression / Q000187:drug effects; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects* / Q000254:growth & development; D016376:Oligonucleotides, Antisense / Q000494:pharmacology*; D020135:Peptide Nucleic Acids / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D057846:Cell-Penetrating Peptides; D003598:Cytoskeletal Proteins; C071525:FtsZ protein, Bacteria; D016376:Oligonucleotides, Antisense; D020135:Peptide Nucleic Acids
keywords: Antisense; Methicillin-resistant; Peptide nucleic acid; Staphylococcus aureus; ftsZ