Mechanisms of Hepatocyte Growth Factor Stimulation of Keratinocyte Metalloproteinase Production

Abstract

Matrix metalloproteinases participate in normal physiologic processes; however, their overproduction has been associated with connective tissue destruction in a variety of pathological states. Migrating basal keratinocytes transiently express collagenase-1 during normal cutaneous reepithelialization. However, the overexpression of both collagenase-1 and stromelysin-1 has been associated with the pathogenesis of chronic nonhealing ulcers. Aberrant expression of metalloproteinases in inflammation is mediated, at least in part, by soluble factors. Since hepatocyte growth factor/scatter factor (HGF/SF) has been reported to promote keratinocyte migration and proliferation, key events in wound repair, and since HGF/SF is produced by dermal fibroblasts and its c-Met receptor is expressed by basal keratinocytes in wounded skin, we have studied the effects of HGF/SF upon keratinocyte metalloproteinase expression. We have found that HGF/SF can stimulate keratinocyte collagenase-1 and stromelysin-1 production in a dose-dependent and matrix-dependent manner. Expression of 92-kDa gelatinase was not affected by HGF/SF. We determined that HGF/SF regulation of collagenase-1 expression is transcriptionally mediated and requires tyrosine kinase and protein kinase C activaties. HGF/ NK1, a naturally occurring, truncated form of HGF/SF, also stimulates collagenase-1 production, but much less efficiently than does the parent molecule. However, HGF/NK2, another HGF/SF splice variant, as well as heparin, potently inhibit HGF/SF-induced collagenase-1 synthesis. These results indicate that HGF/SF and its naturally occurring splice variants have diverse biological effects on keratinocytes and suggest an additional mechanism whereby HGF/SF may regulate keratinocyte function during wound repair.Matrix metalloproteinases are a gene family of zinc-dependent enzymes with the collective capacity to degrade virtually all extracellular matrix components (1). At present, the matrix metalloproteinase gene family consists of three interstitial collagenases (2-4), three stromelysins (5-7), two gelatinases (8, 9), matrilysin (10), metalloelastase (11, 12), and two membrane-type metalloproteinases (13,14). With the notable exception of matrilysin (15, 16), matrix metalloproteinases are not constitutively expressed in normal tissues. Their expression is induced, however, in a variety of physiologic and pathologic conditions, including cutaneous wound repair.Collagenase-1 (MMP-1) 1 and stromelysin-1 (MMP-3) are two matrix metalloproteinases produced by keratinocytes in response to skin injury (17,18,22). These enzymes exhibit distinct substrate specificities and spatial localization within a wound. Collagenase-1 is capable of degrading fibrillar collagens (types I and III), abundant constituents of the dermal matrix, whereas stromelysin-1 degrades basement membrane components such as laminin and proteoglycans. Collagenase-1 is invariably produced by the migrating front of basal keratinocytes in both acute and chronic wounds (17)(18)(19)(20) and is marke...

Autocrine and paracrine motility factors and their involvement in invasiveness in a human oral carcinoma cell line

“…These events are likely to lead to increased cell motility, dissociation of cell-cell interaction and remodelling of cell-substrate interactions. In addition to these events, HGF induces urokinase-type plasminogen activator (uPA) expression (Pepper et al, 1992;Jeffers et al, 1996;Bennett et al, 1997;Date et al, 1998) and stimulates the production of matrix metalloproteinases (MMPs) (Dunsmore et al, 1996;Bennett et al, 1997;Date et al, 1998). Jeffers et al (1996) demonstrated that induction of the uPA proteolysis network by HGF is coupled to enhanced tumorigenicity and invasive and metastatic properties in certain tumour cell lines.…”

Activation Mechanisms of the Urokinase-type Plasminogen Activator Promoter by Hepatocyte Growth Factor/Scatter Factor

“…Indeed two groups of proteases, matrix metalloprotein-ases (12) and the serine protease urokinase (13,14), are upregulated by HGF/SF in different cell lines. Urokinase (15) converts plasminogen into plasmin, a serine protease with broad substrate specificity toward components of the extracellular matrix including laminin, vitronectin, and fibronectin (16 -18).…”

Induction of tissue inhibitor of metalloproteinases-3 is a delayed early cellular response to hepatocyte growth factor

“…Later induction events correlate with HGF-induced epithelial and endothelial cell migration and morphogenesis, including increased production of transcription factor ETS1 (Fafeur et al, 1997), urokinase-type plasminogen activator (u-PA), and its receptor (Pepper et al, 1992), and the zinc ®nger protein slug (Savagner et al, 1997). The HGFstimulated proliferation and migration of keratinocytes that is thought to occur during wound healing Gohda et al, 1994;Watanabe et al, 1994;Nusrat et al, 1994;Sponsel et al, 1994), is accompanied by the induction of collagenase (matrix metalloproteinase 1; MMP-1; Dunsmore et al, 1996;Fafeur et al, 1997) and stromelysin-1 (MMP-3; Dunsmore et al, 1996). These induction events may be coordinated with the HGF-stimulated induction of plasminogen activator inhibitor-1, resulting in appropriate spatial and temporal inhibition of matrix proteolysis (Pepper et al, 1992;Wojta et al, 1994).…”