Cellular factor XIII, a transglutaminase in human corneal keratocytes

Zsuzsanna Z. Orosz, Helga Bárdos, Amir H. Shemirani, Ildikó Beke Debreceni, Riitta Lassila, Antti S. Riikonen, Johanna A. Kremer Hovinga, Theo G. Seiler, Hendrika A. van Dorland, Verena Schroeder, Zoltán Boda, László Nemes, Beatrice Früh Eppstein, Bence Nagy, Andrea Facskó, János Kappelmayer, László Muszbek

Research output: Contribution to journalArticle


Cellular factor XIII (cFXIII, FXIII-A2), a transglutaminase, has been demonstrated in a few cell types. Its main function is to cross-link proteins by isopeptide bonds. Here, we investigated the presence of cFXIII in cells of human cornea. Tissue sections of the cornea were immunostained for FXIII-A in combination with staining for CD34 antigen or isopeptide cross-links. Isolated corneal keratocytes were also evaluated by immunofluorescent microscopy and flow cytometry. FXIII-A in the corneal stroma was quantified by Western blotting. FXIII-A mRNA was detected by RT-qPCR. The cornea of FXIII-A-deficient patients was evaluated by cornea topography. FXIII-A was detected in 68 ± 13% of CD34+ keratocytes. Their distribution in the corneal stroma was unequal; they were most abundant in the subepithelial tertile. cFXIII was of cytoplasmic localization. In the stroma, 3.64 ng cFXIII/mg protein was measured. The synthesis of cFXIII by keratocytes was confirmed by RT-qPCR. Isopeptide cross-links were detected above, but not within the corneal stroma. Slight abnormality of the cornea was detected in six out of nine FXIII-A-deficient patients. The presence of cFXIII in human keratocytes was established for the first time. cFXIII might be involved in maintaining the stability of the cornea and in the corneal wound healing process.

Original languageEnglish
Article number5963
JournalInternational journal of molecular sciences
Issue number23
Publication statusPublished - Dec 2019



  • Cornea
  • Factor XIII
  • Isopeptide bonds
  • Keratocytes
  • Transglutaminase

ASJC Scopus subject areas

  • Catalysis
  • Molecular Biology
  • Spectroscopy
  • Computer Science Applications
  • Physical and Theoretical Chemistry
  • Organic Chemistry
  • Inorganic Chemistry

Cite this

Orosz, Z. Z., Bárdos, H., Shemirani, A. H., Debreceni, I. B., Lassila, R., Riikonen, A. S., Kremer Hovinga, J. A., Seiler, T. G., van Dorland, H. A., Schroeder, V., Boda, Z., Nemes, L., Eppstein, B. F., Nagy, B., Facskó, A., Kappelmayer, J., & Muszbek, L. (2019). Cellular factor XIII, a transglutaminase in human corneal keratocytes. International journal of molecular sciences, 20(23), [5963]. https://doi.org/10.3390/ijms20235963