1
|
Zhang H, Jiang JM, Han L, Lao YZ, Zheng D, Chen YY, Wan SJ, Zheng CW, Tan HS, Li ZG, Xu HX. Uncariitannin, a polyphenolic polymer from Uncaria gambier, attenuates Staphylococcus aureus virulence through an MgrA-mediated regulation of α-hemolysin. Pharmacol Res 2019; 147:104328. [PMID: 31288080 DOI: 10.1016/j.phrs.2019.104328] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/27/2018] [Revised: 06/20/2019] [Accepted: 06/21/2019] [Indexed: 10/26/2022]
Abstract
A global transcriptional regulator, MgrA, was previously identified as a key determinant of virulence in Staphylococcus aureus. An 80% EtOH extract of Uncaria gambier was found to attenuate the virulence of S. aureus via its effects on MgrA. Using bioassay-guided fractionation, a polyphenolic polymer, uncariitannin, was found to be the main bioactive constituent of the extract, and its structure was characterized using spectral and chemical analysis. The molecular weight and polydispersity of uncariitannin were determined by gel permeation chromatography-refractive index-light scattering analysis. An electrophoretic mobility shift assay showed that uncariitannin could effectively inhibit the interaction of MgrA with DNA in a dose-dependent manner. Treatment with uncariitannin could decrease the mRNA and protein levels of Hla in both the S. aureus Newman and USA300 LAC strains. Further analysis of Hla expression levels in the Newman ΔmgrA and Newman ΔmgrA/pYJ335-mgrA strains indicated that uncariitannin altered Hla expression primarily in an MgrA-dependent manner. A mouse model of infection indicated that uncariitannin could attenuate MRSA virulence. In conclusion, uncariitannin may be a potential candidate for further development as an antivirulence agent for the treatment of S. aureus infection.
Collapse
Affiliation(s)
- Hong Zhang
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, PR China; Engineering Research Centre of Shanghai Colleges for TCM New Drug Discovery, Shanghai, 201203, PR China
| | - Jia-Ming Jiang
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, PR China; Engineering Research Centre of Shanghai Colleges for TCM New Drug Discovery, Shanghai, 201203, PR China
| | - Li Han
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, PR China; Engineering Research Centre of Shanghai Colleges for TCM New Drug Discovery, Shanghai, 201203, PR China
| | - Yuan-Zhi Lao
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, PR China; Engineering Research Centre of Shanghai Colleges for TCM New Drug Discovery, Shanghai, 201203, PR China
| | - Dan Zheng
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, PR China; Engineering Research Centre of Shanghai Colleges for TCM New Drug Discovery, Shanghai, 201203, PR China
| | - Yu-Yu Chen
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, PR China; Engineering Research Centre of Shanghai Colleges for TCM New Drug Discovery, Shanghai, 201203, PR China
| | - Shi-Jie Wan
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, PR China; Engineering Research Centre of Shanghai Colleges for TCM New Drug Discovery, Shanghai, 201203, PR China
| | - Chang-Wu Zheng
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, PR China; Engineering Research Centre of Shanghai Colleges for TCM New Drug Discovery, Shanghai, 201203, PR China
| | - Hong-Sheng Tan
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, PR China; Engineering Research Centre of Shanghai Colleges for TCM New Drug Discovery, Shanghai, 201203, PR China
| | - Zi-Gang Li
- School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen, Guangdong, 518055, PR China.
| | - Hong-Xi Xu
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, PR China; Engineering Research Centre of Shanghai Colleges for TCM New Drug Discovery, Shanghai, 201203, PR China.
| |
Collapse
|
2
|
Crosby HA, Kwiecinski J, Horswill AR. Staphylococcus aureus Aggregation and Coagulation Mechanisms, and Their Function in Host-Pathogen Interactions. ADVANCES IN APPLIED MICROBIOLOGY 2016; 96:1-41. [PMID: 27565579 DOI: 10.1016/bs.aambs.2016.07.018] [Citation(s) in RCA: 77] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The human commensal bacterium Staphylococcus aureus can cause a wide range of infections ranging from skin and soft tissue infections to invasive diseases like septicemia, endocarditis, and pneumonia. Muticellular organization almost certainly contributes to S. aureus pathogenesis mechanisms. While there has been considerable focus on biofilm formation and its role in colonizing prosthetic joints and indwelling devices, less attention has been paid to nonsurface-attached group behavior like aggregation and clumping. S. aureus is unique in its ability to coagulate blood, and it also produces multiple fibrinogen-binding proteins that facilitate clumping. Formation of clumps, which are large, tightly packed groups of cells held together by fibrin(ogen), has been demonstrated to be important for S. aureus virulence and immune evasion. Clumps of cells are able to avoid detection by the host's immune system due to a fibrin(ogen) coat that acts as a shield, and the size of the clumps facilitates evasion of phagocytosis. In addition, clumping could be an important early step in establishing infections that involve tight clusters of cells embedded in host matrix proteins, such as soft tissue abscesses and endocarditis. In this review, we discuss clumping mechanisms and regulation, as well as what is known about how clumping contributes to immune evasion.
Collapse
Affiliation(s)
- H A Crosby
- University of Iowa, Iowa City, IA, United States
| | - J Kwiecinski
- University of Iowa, Iowa City, IA, United States
| | - A R Horswill
- University of Iowa, Iowa City, IA, United States
| |
Collapse
|