Role of gelatinase B and elastase in human polymorphonuclear neutrophil migration across basement membrane.

Abstract

Polymorphonuclear neutrophil (PMN) migration across basement membrane is thought to be dependent on the degradation of membrane constituents. PMN gelatinase B, a metalloproteinase able to degrade type IV collagen, may be involved in this phenomenon. PMN gelatinase B is released in the extracellular medium as a latent proform and then activated, mainly by PMN elastase. We investigated the role of gelatinase B in PMN migration across a Matrigel basement membrane matrix coated onto a filter, in a Boyden chamber. The effects of gelatinase and elastase inhibitors on PMN migration in this system were tested. Chemokinesis of PMN was tested in the same Boyden chamber across a filter free of basement membrane. The agarose method was used to test the same inhibitors for effects on PMN chemotaxis. In both systems, FMLP 10(-7)M was used as a chemoattractant. Addition of 10(-8)M TIMP-1 (the preferential gelatinase B inhibitor) inhibited trans-basement membrane PMN migration by 52 +/- 6% (P<0.05), without affecting PMN chemokinesis, chemotaxis, or degranulation. Also, (Ala)(2) Pro Val chloromethyl ketone (AAPVCK) 100 micron, a specific elastase inhibitor, inhibited trans-basement membrane PMN migration by 51 +/- 8% (P<0.05), without affecting PMN chemokinesis, chemotaxis, or degranulation. The AAPVCK-TIMP combination led to a decrease in migration across Matrigel basement membrane (46 +/- 2%, P,0.05)similar to that seen with TIMP alone. AAPVCK was responsible for inhibition of gelatinase B activation, leading to a decrease in activated gelatinase from 14% to 2% of total gelatinase release (P<0.05). All these results strongly suggest that gelatinase B is a major factor of PMN migration across basement membrane and that elastase may contribute to this process by activating pro-gelatinase B.

Venular basement membranes contain specific matrix protein low expression regions that act as exit points for emigrating neutrophils

“…Because the serine protease neutrophil elastase is known to be expressed on the cell surface of transmigrating neutrophils both in vitro (39) and in vivo (32) and has been implicated in neutrophil migration through the BM (17,32,39,40), the role of this protease in disruption of the BM in IL-1β-stimulated tissues was investigated. Data presented here implicate neutrophil-derived serine proteases such as NE in increased size of laminin 10 LE regions during cytokine-induced neutrophil transmigration.…”

“…It is of course highly probable that NE may have indirect roles in mediating neutrophil transmigration, for example, via activation of other leukocyte proteases such as MMP-9 (17) or generation of chemotactic fragments by selective cleavage of BM constituents (42)(43)(44) or cellular receptors. However, NE may also play a direct role in mediating neutrophil transmigration, possibly via cleavage of BM constituents (17,40). In this context, although at present it is unclear whether NE can directly cleave the vascular laminins, laminin 8 and 10, evidence for this possibility was suggested in experiments showing that neutrophils transmigrating through laminin-1-coated fi lters carried laminin on their cell surface in an NE-dependent manner.…”

“…It also serves another important function by providing a distinct and eff ective barrier to leukocytes and macromolecules, a barrier that has to be breached at sites of infl ammation (16). The mechanism by which this occurs in vivo is, however, unknown and although in vitro studies have frequently implicated leukocyte proteases in this response (17), histological studies have consistently failed to identify defects in the structure of the BM at sites of leukocyte migration (16,18). Neutrophils, in particular those that have undergone a transmigration step, express functionally important levels of integrins such as α 2 β 1 (19,20) and α 6 β 1 (21)(22)(23), receptors for collagen IV and laminins, respectively.…”

PMA-induced up-regulation of MMP-9 is regulated by a PKCα-NF-κB cascade in human lung epithelial cells

“…These enzymes have been shown to play key roles in tumor cell invasion, metastasis and angiogenesis by promoting ECM degradation and the processing of cytokines, growth factors, hormones and cell receptors (John and Tuszynski, 2001;Nguyen et al, 2001). MMPs are produced not only by structural cells including fibroblasts, endothelial cells and epithelial cells (Bove et al, 2007) but also by inflammatory cells such as macrophages (Mautino et al, 1997;Lee et al, 2006), lymphocytes (Owen et al, 2003), neutrophils (Delclaux et al, 1996) and eosinophils (Fujisawa et al, 1999). By degrading components of the ECM, MMPs are thought to play a role in tissue remodeling and the accumulation of inflammatory cells associated with asthma (Kelly and Jarjour, 2003).…”

Neutrophil elastase ameliorates matrix metalloproteinase-9 to promote lipopolysaccharide-induced acute lung injury in mice 1

“…MMP-9 inhibition by MMP inhibitors can reduce neutrophil transmigration. The elevated level of MMP-9 in the bronchoalveolar lavage fluid (BALF) in ALI has been suggested to play a role in neutrophil-mediated ALI and the corresponding inflammatory responses [5][6][7][8][9] .…”