Heparin affects the interaction of kininogen on endothelial cells

Abstract

In the plasma kallikrein-kinin system, it has been shown that when plasma prekallikrein (PK) and high molecular weight kininogen (HK) assemble on endothelial cells, plasma kallikrein (huPK) becomes available to cleave HK, releasing bradykinin, a potent mediator of the inflammatory response. Because the formation of soluble glycosaminoglycans occurs concomitantly during the inflammatory processes, the effect of these polysaccharides on the interaction of HK on the cell surface or extracellular matrix (ECM) of two endothelial cell lines (ECV304 and RAEC) was investigated. In the presence of Zn(+2), HK binding to the surface or ECM of RAEC was abolished by heparin; reduced by heparan sulfate, keratan sulfate, chondroitin 4-sulfate or dermatan sulfate; and not affected by chondroitin 6-sulfate. By contrast, only heparin reduced HK binding to the ECV304 cell surface or ECM. Using heparin-correlated molecules such as low molecular weight dextran sulfate, low molecular weight heparin and N-desulfated heparin, we suggest that these effects were mainly dependent on the charge density and on the N-sulfated glucosamine present in heparin. Surprisingly, PK binding to cell- or ECM-bound-HK and PK activation was not modified by heparin. However, the hydrolysis of HK by huPK, releasing BK in the fluid phase, was augmented by this glycosaminoglycan in the presence of Zn(2+). Thus, a functional dichotomy exists in which soluble glycosaminoglycans may possibly either increase or decrease the formation of BK. In conclusion, glycosaminoglycans that accumulated in inflammatory fluids or used as a therapeutic drug (e.g., heparin) could act as pro- or anti-inflammatory mediators depending on different factors within the cell environment.

The Involvement of Proteoglycans in the Human Plasma Prekallikrein Interaction with the Cell Surface

“…Indeed it is well known that GAGs interact with H-kininogen at the endothelial cell surface [9], [11], [27], as well as GAGs also interact with plasma kallikrein modifying its kinetics behavior [36], [37]. Prekallikrein interaction with cells may generate plasma kallikrein by proteolytic cleavage and its activity can be analyzed by H-kininogen structure.…”

“…Plasma kallikrein-kinin proteins have also been found on the surface and in the extracellular matrix of endothelial cells from line ECV304 [23], vascular smooth muscle cells [24], immortalized human EA.hy926 endothelial cells [25], lung epithelial cells [26] and endothelial cells from a line derived from rabbit aorta RAECs [27]. Little is known regarding the mechanisms of plasma prekallikrein interactions with cells.…”

Bradykinin Release Avoids High Molecular Weight Kininogen Endocytosis

“…On the cell surface, H-kininogen binds to heparan sulfate (HS) or chondroitin sulfate (CS) proteoglycans (PGs) [ 13 ], [ 14 ], and HSPG appear to play a critical role in recruiting kinin precursors from the plasma and in the assembly of components triggering the release of active kinins from their precursors in proximity to their target cells [ 15 ]. Indeed, glycosaminoglycans (GAGs) that accumulate in the inflammatory fluids could act as pro- or anti-inflammatory mediators depending on different factors within the cell environment [ 16 ]. The H-kininogen interaction with HS on the cell surface results in its endocytosis into acidic vessels [ 17 ].…”

Novel hereditary angioedema linked with a heparan sulfate 3-O-sulfotransferase 6 gene mutation

“…37 Further evidence supporting a potentially specific role of HS in localizing HK to the cellular surface comes from experiments that show reduced surface HK surface binding in the presence of soluble HS in rabbit aorta endothelial cells. 38 A potential mechanism for how HS could influence bradykinin cleavage on the cellular surface is through defects in cellular uptake; it has been shown that HS proteoglycans mediate endocytosis of HK, 39,40 which could have potential influence on bradykinin generation and/or targeting. This leads us to the following hypothesis regarding the effect of the HS3ST6 mutation on angioedema formation in the patients with HAE who belonged to the family described in this study.…”