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Updated: May 25, 2026
A Mouse Model to Assess Innate Immune Response to Staphylococcus aureus Infection
Published on: February 28, 2019
Lipoteichoic acid from Staphylococcus aureus induced expression of MMP-9 in human middle ear epithelial cells
Hun Yi Park1, Jung-Whan Song, Sung Pyo Hong
1Department of Otolaryngology, Ajou University School of Medicine, Suwon, Republic of Korea.
Objective:
Change in matrix metalloproteinases (MMPs) and regulation of their tissue inhibitors of metalloproteinases (TIMPs) could play certain role in the pathogenesis of otitis media. This study was designed to evaluate the modulation of MMPs and TIMPs in middle ear epithelium by lipoteichoic acid (LTA) isolated from Staphylococcus aureus.
Methods:
Human middle ear epithelial (HMEE) cells were treated with LTA. MMP activities were examined by PCR, ELISA and zymography, and levels of TIMPs were measured by PCR and ELISA.
Results:
LTA isolated from S. aureus increased MMP-9 mRNA expression and secretion in HMEE cells, whereas no effect on the expressions of MMP-1, -2, -3, -7 and TIMP-1, -2 was observed.
Conclusions:
LTA increased the activity of MMP-9, not TIMPs in middle ear epithelia, suggesting that disturbed balance between MMP-9 and TIMPs could play an active role in LTA-induced otitis media.
Insights
Staphylococcus aureus lipoteichoic acid (LTA) increases matrix metalloproteinase-9 (MMP-9) in middle ear cells. This suggests an imbalance between MMP-9 and its inhibitors contributes to otitis media pathogenesis.
Area of Science:
- Otolaryngology
- Microbiology
- Biochemistry
Background:
- Otitis media pathogenesis involves changes in matrix metalloproteinases (MMPs) and their inhibitors (TIMPs).
- Lipoteichoic acid (LTA) from Staphylococcus aureus is a key factor in bacterial infections.
Purpose of the Study:
- To investigate the effect of Staphylococcus aureus LTA on MMPs and TIMPs in human middle ear epithelial cells.
- To understand the role of LTA in the molecular mechanisms of otitis media.
Main Methods:
- Human middle ear epithelial cells were exposed to LTA.
- MMP expression and activity were analyzed using PCR, ELISA, and zymography.
- TIMP levels were quantified via PCR and ELISA.
Main Results:
- LTA significantly increased MMP-9 mRNA expression and secretion.
- No significant changes were observed in MMP-1, -2, -3, -7, or TIMP-1, -2 levels.
- MMP-9 activity was elevated, while TIMP levels remained unaffected.
Conclusions:
- LTA upregulates MMP-9 activity in middle ear epithelium.
- The imbalance between MMP-9 and TIMPs induced by LTA may contribute to otitis media development.
- Targeting MMP-9 could be a potential therapeutic strategy for LTA-induced otitis media.