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EMMPRIN and MMP-1 in keratoconus
Hannu P S Seppälä1, Marko Määttä, Mikko Rautia
1Department of Medicine, Helsinki University Central Hospital, Helsinki, Finland.
Purpose:
This study was conducted to determine the eventual presence and activity of EMMPRIN (extracellular matrix metalloproteinase inducer CD147) and interstitial collagenase MMP-1 in the cornea of keratoconus patients and their eventual interrelationship. MMP-1 was chosen because it is able to degrade fibrillar corneal collagens type I and III and might therefore play a role in stromal thinning in keratoconus.
Methods:
Immunohistochemical labeling of EMMPRIN and MMP-1 in relation to histopathological changes in 5 keratoconus patients and 5 matched healthy controls was investigated.
Results:
Relatively strong EMMPRIN expression was found in normal corneal epithelial cells, but moderate expression was also found in stroma. In keratoconus, EMMPRIN was found in all layers of cornea, especially in histopathologically altered areas. In normal cornea, MMP-1 staining was weak and restricted to epithelial cells. In keratoconus, MMP-1 expression was slightly augmented in epithelial cells and also appeared locally in a scattered manner in the stroma. The distribution of MMP-1 did not totally overlap with that of histologically apparent corneal damage and EMMPRIN expression.
Conclusions:
Both EMMPRIN and MMP-1 are upregulated in keratoconus, but MMP-1 may not be the only tissue destructive MMP upregulated by EMMPRIN as only EMMPRIN expression correlated topologically very well with corneal damage.
Insights
Extracellular matrix metalloproteinase inducer (EMMPRIN) and matrix metalloproteinase-1 (MMP-1) are elevated in keratoconus corneas. EMMPRIN expression strongly correlates with corneal damage, suggesting its key role in keratoconus progression.
Area of Science:
- Ophthalmology
- Corneal Biology
- Biochemistry
Background:
- Keratoconus is a progressive thinning of the cornea.
- The role of specific matrix metalloproteinases (MMPs) in keratoconus pathogenesis is not fully understood.
- Extracellular matrix metalloproteinase inducer (EMMPRIN/CD147) and MMP-1 are implicated in tissue remodeling.
Purpose of the Study:
- To investigate the presence and activity of EMMPRIN and MMP-1 in keratoconus corneas.
- To determine the interrelationship between EMMPRIN, MMP-1, and histopathological changes in keratoconus.
- To assess the potential role of MMP-1 in stromal thinning associated with keratoconus.
Main Methods:
- Immunohistochemical labeling was used to detect EMMPRIN and MMP-1.
- Corneal tissues from 5 keratoconus patients and 5 healthy controls were analyzed.
- Histopathological changes were correlated with protein expression patterns.
Main Results:
- EMMPRIN expression was detected in all corneal layers of keratoconus patients, particularly in damaged areas.
- MMP-1 expression was slightly increased in epithelial cells and scattered in the stroma of keratoconus corneas.
- MMP-1 distribution did not perfectly overlap with corneal damage or EMMPRIN expression.
Conclusions:
- Both EMMPRIN and MMP-1 are upregulated in keratoconus.
- EMMPRIN expression shows a strong topological correlation with corneal damage in keratoconus.
- EMMPRIN may be a key regulator of tissue-degrading MMPs in keratoconus, but MMP-1 alone may not account for all observed damage.
