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Updated: Oct 21, 2025
Following in Real Time the Impact of Pneumococcal Virulence Factors in an Acute Mouse Pneumonia Model Using Bioluminescent Bacteria
Published on: February 23, 2014
Myricetin protects mice against MRSA-related lethal pneumonia by targeting ClpP
Shisong Jing1, Li Wang2, Tiedong Wang2
1Department of Pharmacology, School of Pharmaceutical Science, Jilin University, Changchun 130021, China; College of Animal Science, Jilin University, Changchun 130062, China.
Abstract:
Methicillin-resistant Staphylococcus aureus is one of the leading causes of community and nosocomial infections, which has created the urgent need for innovative anti-infective agents to control MRSA-associated infections. A conserved serine protease, caseinolytic peptidase P (ClpP) in Staphylococcus aureus is highly associated with pathogenicity and has been claimed to be a novel antimicrobial target. We aim to search suitable inhibitors of ClpP to attenuate the virulence of MRSA and combat their infections in vivo. Over 500 natural compounds were pre-screened via fluorescence resonance energy transfer using the Suc-LY-AMC substrate. The binding of myricetin to ClpP was determined and the mechanism of action was elucidated by thermal shift assay, surface plasmon resonance, and molecular dynamics simulations. The therapeutic effects of myricetin on S. aureus infection were further investigated using a S. aureus-induced pneumonia model. We revealed that myricetin could effectively block the activity of ClpP without disturbing the growth of the bacteria and the Gln-47 and Met-31 residues were necessary for myricetin binding to ClpP. Importantly, myricetin attenuated the pathogenicity of S. aureus in vivo, while improving the efficacy of the traditional antibiotic oxacillin against MRSA infection and protecting mice from fatal lung infections caused by MRSA. These findings indicate that myricetin has the potential to be applied in the pharmaceutical industry as a promising therapeutic agent.
Insights
Myricetin effectively inhibits Staphylococcus aureus ClpP protease activity, reducing virulence without harming bacteria. This natural compound shows promise in treating MRSA infections and enhancing antibiotic efficacy.
Area of Science:
- Microbiology
- Pharmacology
- Biochemistry
Background:
- Methicillin-resistant Staphylococcus aureus (MRSA) poses a significant threat, driving the need for novel anti-infective strategies.
- Staphylococcus aureus caseinolytic peptidase P (ClpP) is a validated target for combating MRSA infections due to its role in pathogenicity.
Purpose of the Study:
- To identify and characterize inhibitors of ClpP to attenuate MRSA virulence.
- To evaluate the therapeutic potential of identified inhibitors against MRSA infections in vivo.
Main Methods:
- High-throughput screening of over 500 natural compounds using fluorescence resonance energy transfer (FRET).
- Biophysical techniques including thermal shift assay and surface plasmon resonance (SPR) to determine binding and mechanism of action.
- Molecular dynamics simulations and in vivo studies using a MRSA-induced pneumonia mouse model.
Main Results:
- Myricetin identified as a potent ClpP inhibitor, blocking protease activity without affecting bacterial growth.
- Myricetin binding to ClpP involves specific residues Gln-47 and Met-31, elucidated through biophysical and simulation methods.
- In vivo studies demonstrated myricetin's ability to attenuate MRSA pathogenicity, enhance oxacillin efficacy, and protect against lethal pneumonia.
Conclusions:
- Myricetin is a promising therapeutic agent targeting ClpP for MRSA infections.
- Myricetin offers a potential strategy to combat antibiotic-resistant bacterial infections.
- Further pharmaceutical development of myricetin for MRSA treatment is warranted.
