In addition to the plasma where factor XIII subunit A is present as part of the heterodimers
of the tetrameric fibrin-stabilizing factor, homodimers of factor XIII A can also
be detected in cellular localization in different human tissues. Experimental findings
verified that these cells belong to the megakaryocyte/platelet and the monocyte/macrophage
cell lines. Additionally, factor XIII A is present in hepatocytes localized mainly
around central veins in the liver and occasionally expressed in certain malignantly
transformed cells. It is reasonable to suppose that factor XIII A acts not only as
a member of the clotting cascade, but also as a cellular enzyme that can catalyze
molecular interactions intracellularly (during the assembly/reassembly of the cytoskeleton)
or extracellularly (in the connective tissue matrix around the cells containing it).
Factor XIII - monocytes - macrophages - megakaryocytes - platelets - hepatocytes
