S100A10 regulates plasminogen-dependent macrophage invasion

Abstract

The plasminogen activation system plays an integral role in the migration of macrophages in response to an inflammatory stimulus, and the binding of plasminogen to its cell-surface receptor initiates this process. Although previous studies from our laboratory have shown the importance of the plasminogen receptor S100A10 in cancer cell plasmin production, the potential role of this protein in macrophage migration has not been investigated. Using thioglycollate to induce a peritoneal inflammatory response, we demonstrate, for the first time, that compared with wild-type (WT) mice, macrophage migration across the peritoneal membrane into the peritoneal cavity in S100A10-deficient (S100A10 ؊/؊ ) mice was decreased by up to 53% at 24, 48, and 72 hours. Furthermore, the number of S100A10-deficient macrophages that infiltrated Matrigel plugs was reduced by 8-fold compared with their WT counterpart in vivo. Compared with WT macrophages, macrophages from S100A10 ؊/؊ mice demonstrated a 50% reduction in plasmin-dependent invasion across a Matrigel barrier and a 45% reduction in plasmin generation in vitro. This loss in plasmin-dependent invasion was in part the result of a decreased generation of plasmin and a decreased activation of pro-MMP-9 by S100A10-deficient macrophages. This study establishes a direct involvement of S100A10 in macrophage recruitment in response to inflammatory stimuli. (Blood. 2010;116(7): 1136-1146) IntroductionMonocytes/macrophages play a central role in pathogenic inflammatory responses associated with atherosclerosis, restenosis, tumor surveillance, and arthritis. [1][2][3] In response to changes in the cellular environment, monocytes and monocytoid cells undergo extensive phenotypic alterations, including marked changes in their fibrinolytic properties. Synthesis and activation of matrix-degrading proteinases by monocytes and macrophages play an essential role in their migration through tissue. A key proteinase that participates in pericellular proteolysis is the serine proteinase plasmin. Plasmin is a broad substrate proteinase that is formed from the inactive zymogen plasminogen (Plg) by the Plg activators, tissue Plg activator (tPA) and urokinase-type Plg activator (uPA). 4,5 The participation of plasmin in cell invasion and migration is dependent on the ability of plasmin not only to degrade extracellular matrix (ECM) proteins but to also activate other proteinases that have matrix-degrading activity. Plasmin can degrade a variety of matrix proteins, such as laminin and fibronectin, and appears to activate matrix metalloproteinase-1 (MMP-1), MMP-3, and MMP-13 directly, and to activate MMP-2 and MMP-9 indirectly, thereby facilitating cell migration through ECMs. 6 The assembly of Plg and its activators on the cell surface is facilitated by the protein S100A10 (also referred to as p11). S100A10 is a member of the S100 family of calcium-binding proteins and is typically found in most cells bound to its annexin A2 (p36) ligand as the heterotetrameric (S100A10) 2 -(annexin A2) 2 complex, annexi...

Urokinase Plasminogen Activator Is a Central Regulator of Macrophage Three-Dimensional Invasion, Matrix Degradation, and Adhesion

“…Also, in the absence of MMP9, macrophages were completely unable to respond to Plg for increased 3D invasion and matrix degradation, indicating its importance in the downstream proteolytic events initiated by uPA/Plg. Consistent with our data, Thio-Mw in the presence of Plg generate active MMP9 (63), and if these macrophages are elicited from MMP9 2/2 mice, they fail to respond to Plg for increased 3D invasion (64). In that study, MMP9 2/2 ThioMw had no defect in 3D invasion, which differs from our finding with MMP9 2/2 BMM and with uPA 2/2 Thio-Mw.…”

Plasmin Induces In Vivo Monocyte Recruitment through Protease-Activated Receptor-1–, MEK/ERK-, and CCR2-Mediated Signaling

“…This suggestion is currently under investigation in our laboratory. Several Plg receptors have been shown to participate in Plainduced migration in vivo and in vitro (12)(13)(14)(15)45). These receptors have two common properties: they possess a carboxyl-terminal lysine residue that can bind Plg and they are not transmembrane proteins but become expressed on the cell surface by yet undefined pathways (46).…”

The role of the annexin A2 heterotetramer in vascular fibrinolysis

“…41 Analysis of cell surface ANXA2 has identified intact ANXA2 but failed to observe any truncated ANXA2. 37,39,40 Recently, we examined the molecular weight forms of ANXA2 at the endothelial cell surface by Western blotting. 41 Although native ANXA2 was easily detected, we were unable to detect any lower molecular weight (truncated) forms of ANXA2.…”

“…34 Shortly after these reports, another group demonstrated the presence of S100A10 on the surface of endothelial cells and the reversible interaction of the C-terminal lysine of S100A10 with both tPA and plasminogen. 35,36 This group established that S100A10 was present in a heterotetrameric complex with ANXA2 on the surface of many cells 35,[37][38][39][40][41] and demonstrated that purified AIIt bound tPA and plasminogen via the C-terminal lysine of the S100A10 subunit without the participation of the ANXA2 subunit. 36,42,43 With the development of methods to deplete cells of ANXA2 and the report of defective fibrinolysis in the ANXA2 knockout mouse, 44 it appeared that ANXA2 might play a role in cellular fibrinolysis.…”