Identification of normal human peripheral blood monocytes and liver as sites of synthesis of coagulation factor XIII a-chain

Abstract

Factor XIII is the fibrin-stabilizing factor that covalently cross- links fibrin monomers to form a highly organized, stable fibrin clot. The plasma form of factor XIII is a heterodimer, a2b2, consisting of two a-chains and two b-chains; the intracellular form, such as in platelets and placenta, is a dimer, a2, consisting of a-chains only. The catalytic function of factor XIII, a transglutaminase, resides in the a-chain. To address questions regarding sites of synthesis of factor XIII a-chain, an EcoRI restriction fragment from the protein- coding region of the factor XIII a-chain cDNA was used as a probe for Northern blot analysis. The cDNA probe showed hybridization with a single approximately 4.0-kilobase (kb) message in poly (A)+ mRNA prepared from normal human peripheral blood monocytes and normal human liver. The results demonstrate conclusively that factor XIII a-chains are actively synthesized in circulating monocytes and in liver. To our knowledge, these data represent the first demonstration of synthesis of any blood coagulation factor in primary uncultured and unstimulated monocytes or macrophage cells.

Blood coagulation factor XIII contributes to the development of traction retinal detachment

“…About half of the cells labelled by the anti-macrophage antibody stained for the a-unit of factor XI11 (Fig. 3) but not for the (J-unit, consistent with earlier results (Weisberg et al 1987). The mononuclear phagocyte system is a cellular population 250 with multiple biologic functions (Nathan 1987), including the production of procoagulant factors which may induce extracellular deposition of fibrin (Helin 1986).…”

“…Factor XI11 has been detected in plasma as a tetrameric form (a&*) (Schwartz et al 1973). The asubunit occurs as a dimer (a2) in platelets, blood monocytes, in the liver, and in the placenta (Schwartz et al 1973;Weisberg et al 1987) while the origin of the (3-chain is probably the liver (Nagy et al 1986). Recently the (J-subunit has also been demonstrated in bovine platelets (Takagi et al 1988).…”

“…The enzyme operates as a tetrameric complex of an a,@,-type. The a-chain with a molecular weight of 75-83 kDa is the cata-246 lytic moiety (Schwartz et al 1973, Weisberg et al 1987). The precise function of the P-chain (80-88 kDa) is unknown, but further functions, in addition to the complex formation with the a-chains of factor XIII, are likely (Takagi et al 1988).…”

Factor XIIIa+ dermal dendrocytes in erythema elevatum diutinum and ordinary cutaneous leukocytoclastic vasculitis lesions

“…The larger number of fXIIIa π DD observed in EED and OLV could be correlated to their possible function as a source of factor XIIIa in stabilizing fibrin in the dermis exudate. 12,28 The results obtained suggest the involvement of fXIIIa π DD in the immunopathological mechanism in both groups of vasculitis studied. These cells appeared hypertrophic and were increased in number in both lesions when compared to normal skin.…”

Ultrastructural localization of factor XIIIa

“…Factor XIII (FXIII) is a Hbriu stabilizing factor whicb covalently cros.s-links fibrin monomer to protein to form a stable clot (1,2). Two forms of FXIII exist: an extracelltilar or plasma FXIII and an intracellnlar FXIII (2).…”