Cellular Factor XIII, a Transglutaminase in Human Corneal Keratocytes
Zsuzsanna Z Orosz1,2, Helga Bárdos3, Amir H Shemirani1
1Division of Clinical Laboratory Science, Department of Laboratory Medicine, University of Debrecen, Faculty of General Medicine, 4032 Debrecen, Hungary.
International Journal of Molecular Sciences
|December 1, 2019
Summary
Cellular factor XIII (cFXIII) was found in human corneal keratocytes for the first time. This enzyme may play a role in maintaining corneal stability and aiding wound healing.
Area of Science:
- Ophthalmology
- Cell Biology
- Biochemistry
Background:
- Cellular factor XIII (cFXIII), a transglutaminase, cross-links proteins via isopeptide bonds.
- Its presence and function in corneal cells were previously uncharacterized.
Purpose of the Study:
- To investigate the presence and localization of cFXIII in human corneal cells.
- To explore the potential role of cFXIII in corneal structure and healing.
Main Methods:
- Immunohistochemistry on corneal tissue sections (FXIII-A, CD34, isopeptide cross-links).
- Immunofluorescence microscopy and flow cytometry on isolated corneal keratocytes.
- Western blotting and RT-qPCR for FXIII-A quantification and mRNA detection.
- Corneal topography in FXIII-A-deficient patients.
Main Results:
- FXIII-A was detected in 68% of CD34+ keratocytes, primarily in the subepithelial stroma.
- cFXIII showed cytoplasmic localization within keratocytes.
- Western blotting measured 3.64 ng cFXIII/mg protein in the stroma.
- RT-qPCR confirmed FXIII-A synthesis by keratocytes.
- Isopeptide cross-links were found above, but not within, the corneal stroma.
- Mild corneal abnormalities were observed in FXIII-A-deficient individuals.
Conclusions:
- The presence of cFXIII in human corneal keratocytes is established for the first time.
- cFXIII may contribute to corneal stability.
- cFXIII is potentially involved in the corneal wound healing process.
