It is reasonable to assume, based on the research partly reviewed here, that collage-nase-1 has a key role in the wound healing process. Expression of collagenase in dermal cells, consistently found in repairing skin wounds seems more logical than the finding of collagenase in epithelial cells. Tissue repair involves the turnover of dermal fibrillar collagen, a process requiring the proteolytic activity of collagenases. Increased collagenolysis is needed throughout the remodeling phase leading to the formation of a mature scar, a process requiring months. During this period, there are marked changes in collagen composition, and the amount of type III collagen. Although transiently present in elevated levels in the early wound matrix, type III collagen expression decreases, and shifts towards the formation of type I collagen and the subsequent maturation of collagen into thicker and more compact fibers. Collagenases are obvious participants in this process and collagenase-1 seems to be the principal enzyme involved, although neutrophil collagenase released from migratory inflammatory cells may assist in collagen degradation. The potential role for collagenase 3 in this context is only beginning to be studied. Our own data do not show evidence of collagenase 3 expression in acute skin wounding (Stähle-Bäckdahl, unpublished observations). However, Saarialho-Kere recently showed that collagenase 3 was expressed by dermal fibroblasts in chronic wounds, suggesting that collagenase 3 may be involved in matrix remodeling associated with wounding.95
There is no doubt that the principal function of epidermal cells expressing collagenase is in closing the wound by cell migration and proliferation. What is the specific role for collagenase-1 in this setting, and is it critical for cell immigration? A hypothesis recently advanced is that collagenase activity is necessary for the keratinocyte to achieve re-epithe-lialization. In support of this idea Pilcher et al have shown that keratinocyte migration in vitro is dependant upon catalytically functional collagenase.63 As discussed earlier, it is well-established that keratinocytes migrating on type I collagen produce collagenase in vitro. Indeed, when blocking collagenase activity in this system, the keratinocytes failed to migrate. It was further hypothesized that keratinocyte migration would only occur in association with collagenase cleaving collagen molecules. Consistent with this, it was shown that the cells did not migrate on mutant collagen lacking the collagenase cleavage site, a finding strongly linking collagenase catalytic activity to keratinocyte movement. Thus, there is substantial evidence supporting a direct role for collagenase in keratinocyte migration. Moreover, in this model the authors proposed that by cleaving collagen fibers, collagenase actually serves to direct the keratinocytes during migration; the keratinocytes are provided fresh collagen substrate ahead and leave behind digested gelatin fragments no longer attracting collagenase. Admittedly, it is tempting to speculate that the critical role for collagenase in re-epithelialization utilizes its unique biological role. However, even though collagenase may be required for cell migration and epithelial regeneration, its precise functions in the wounded epidermis are more elusive. The assumption is that re-epithelialization in different tissues follows similar if not identical mechanisms. Consistent with this are experimental data on mucosal healing showing that analogous to the situation in skin, contact with type I collagen stimulates epithelial cell migration more than does contact with fibronectin and laminin. Therefore, it is somewhat surprising that healing of ulcers in the gastrointestinal mucosa does not seem to involve collagenase-1. In such lesions there is distinct expression of matrilysin (MMP-7) but not collagenase-1 in the wound edge epithelium, the latter detected only in the stromal tissue underneath. Matrilysin has a broad substrate specificity but it does not cleave type I collagen, indicating a different role in re-epithelialization that does not involve collagen.
Another interesting question concerns the role of type III collagen in this setting. Type III collagen is the preferred substrate for collagenase-1 in vitro and one might infer that collagenase-1 may have evolved to serve a unique role in tissues containing by a high collagen III content. In fresh wounds the deposition of granulation tissue occurs in an orderly sequence lead by fibronectin, followed by type III collagen, and then by type I collagen. This time course seems to match the appearance of collagenase-1 expression in wound edge keratinocytes and it is tempting to connect the two. Does type III collagen induce collage-nase-1 in migrating keratinocytes?
A clinically relevant issue concerns chronic skin ulcers. By their chronic nature, these ulcers have a problem in the process of healing. Despite overexpression of collagenase-1 in such wounds, at levels even more pronounced than in acute wounds,37 these ulcers do not re-epithelialize effectively. So, even though collagenase-1 may be required for re-epithelial-ization, it is not sufficient for keratinocyte migration to take place. Despite ample collage-nase-1 production, epithelial cells in chronic wounds lose their migratory phenotype and "forget" that they are wound edge keratinocytes. These keratinocytes can temporarily reassume a migratory phenotype if challenged by additional injury. In clinical practice, use is made of this empirical observation when performing surgical revision of a wound, which sometimes enhances re-epithelialization. What is the mysterious signal elicited by the injury that can stimulate the keratinocytes to migrate? One can speculate about the signals involved, but clearly it is not solely the upregulation of collagenase-1.
In summary, research over the past few years has shown us that collagenase-1 is a key component of skin wound healing. Besides participating in the remodeling of the wounded dermal tissue, collagenase-1 serves a distinct role in epithelial wound closure. Many questions remain, but additional insight into the mechanisms of keratinocyte migration will provide us with powerful tools to effectively intervene in and facilitate the wound healing process.
The Karolinska Institute and the Welander-Finsen Foundation are gratefully acknowledged for financial support and the Journal for Investigative Dermatology for the use of figures published in the journal 104:479-483, 1995.
1. Goss RJ. Deer antler. Regeneration, function and evolution. New York:Academic Press 1983.
2. Linzmeier R, Michaleson D, Liu L et al. The structure of neutrophil defensin genes. FEBS 1993; 321:267-273.
3. Gabbiano G, Hirschel BJ, Ryan GB et al. Granulation tissue as a contractile organ. A study of structure and function. J Exp Med 1972; 135:19-734.
4. Levenson SM, Greever EF, Crowley LV et al. The healing of rat skin wounds. Ann Surg 1965;161:293-308.
5. Lazarus GS, Brown RS, Daniels JR et al. Degradation of collagen by a human granulocyte collagenolytic system. J Clin Invest 1968; 47:2622-2629.
6. Robertson PB, Ryel RB, Taylor RE et al. Collagenase: Localization in polymorphonuclear leukocyte granules in the rabbit. Science 1972;177:64-65.
7. Werb A, Gordon S. Secretion of a specific collagenase by stimulated macrophages. J Exp Med 1975;142:346-360.
8. Maniardi CL, Hasty KA, Hibbs MS. Type specific collagen degradation. Adv Inflam Res 1986; 11:135-144.
9. Donoff RB, McLennan JE, Grillo HC. Preparation and properties of collagenases from epithelium and mesenchyme of healing mammalian wounds. Biochem Biophys Acta 1971; 227:639-653.
10. Birkedal-Hansen H. Catabolism and turnover of collagens: Collagenases. Methods Enzymol 1987; 144:140-171.
11. Gross J, Harper E, Harris ED Jr et al. Animal collagenases; distribution, specificity of action and structure of the substrate cleavage site Biochem Biophys Res Commun 1974; 61:605-612.
12. Seltzer JL, Adams SA, Grant GA et al. Purification and properties of a gelatin-specific neutral protease from human skin. J Biol Chem 1981; 256:4662-4668.
13. Welgus HG, Jeffrey J, Stricklin GP et al. Characteristics of the action of human skin fibroblast collagenase on fibrillar collagen. J Biol Chem 1980; 255:6806-6813.
14. Welgus HG, Jeffrey J J, Stricklin GP et al. The gelatinolytic activity of human skin fibroblast collagenase. J Biol Chem 1982; 256:9511-9515.
15. Stricklin GP, Bauer EA, Jeffrey JJ et al. Human skin collagenase: Isolation of precursor and active forms from fibroblast and organ cultures. Biochemistry 1977; 16:1607-1615.
16. Welgus HG, Campbell EJ, Bar-Shavit Z et al. Human alveolar macrophages produce a fi-broblast-like collagenase and collagenase inhibitor. J Clin Invest 1985; 76:219-224.
17. Lazarus GS, Brown RS, Daniels JR et al. Human granulocyte collagenase. Science 1968; 159:1483-1485.
18. Murphy G, Reynolds JJ, Bretz U et al. Collagenase is a component of the specific granules of human neutrophil leukocytes. Biochem J 1977; 162:195-197.
19. Freije JMP, Diaz-Itza J, Balbin M et al. Molecular cloning and expression of collagenase 3, a novel human matrix metalloproteinase produced by breast carcinomas. J Biol Chem 1994; 269:16766-16773.
20. Lin H-Y, Wells BR, Taylor RE et al. Degradation of type I collagen by rat mucosal keratinocytes. J Biol Chem 1987; 262:6823-6831.
21. Petersen MJ, Woodley DT, Stricklin GP et al. Production of procollagenase by cultured human keratinocytes. J Biol Chem 1987; 262:835-840.
22. Moscatelli D, Jaffe E, Rifkin DB. Tetradecanoyl phorbol acetate stimulates latent human collagenase production by cultured human endothelial cells. Cell 1980; 20:343-351.
23. Campell, E.J, Cury JD, Lazarus CJ et al. Monocyte procollagenase and tissue inhibitor of metalloproteinases. Identification, characterization, and regulation of secretion. J Biol Chem 1987; 262:15862-15868.
24. Lefebvre V, Peeters-Joris C, Vaes G et al. Modulation by interleukin-1 and tumor necrosis factor a of production of collagenase, tissue inhibitor of metalloproteinases and collagen types in differentiated and dedifferentiated articular chondrocytes. Biochem Biophys Acta 1990; 1052:366-378.
25. Quinn CO, Scott DK, Brinckerhoff CE et al. Rat collagenase. Cloning, amino acid sequence comparison and parathyroid hormone regulation in osteoblastic cells. J Biol Chem 1990; 265:22342-22347.
26. Gabbiano G, Lelous L, Bailey AJ et al. Collagen and myofibroblasts of granulation tissue. A chemical, ultrastructural and immunologic study. Cell Pathol 1976; 21:133-145.
27. Knäuper V, Lopez-Otin C, Smith B et al. Biochemical characterization of human collage-nase-3. J Biol Chem 1996; 271:1544-1550.
28. Mitchell PG, Magna HA, Reeves LM et al. Cloning, expression, and type II collagenolytic activity of matrix metalloproteinase-13 from human osteoarthritic cartilage. J Clin Invest 1996; 97:761-768.
29. Angel P, Imagawa M, Chiu R et al. Phorbol ester-inducible genes contain a common cis element recognized by a TPA-modulated trans-acting factor. Cell 1987; 49:729-739.
30. Auble DT, Brinckerhoff CE. The AP-1 sequence is necessary but not sufficient for phorbol induction of collagenase in fibroblasts. Biochemistry 1991; 30:4629-4635.
31. Pendas AM, Balbin M, Llano E et al. Structural analysis and promoter characterization of the human collagenase-3 gene (MMP-13). Genomics 1997; 40:222-233.
32. Nerlov C, Rorth P, Blasi F et al. Essential AP-1 and PEA3 binding elements in the human urokinase enhancer display cell-type specific activity. Oncogene 1991; 6:1583-1592.
33. Wasylyk C, Gutman A, Nocholson R et al. The c-Ets oncoprotein activates the stromelysin promoter through the same elements as several nonnuclear oncoproteins. EMBO J 1991; 10:1127-1134.
34. Saarialho-Kere UK, Chang ES, Welgus HG et al. Distinct localization of collagenase and tissue inhibitor of metalloproteinases expression in wound healing associated with ulcerative pyogenic granuloma. J Clin Invest 1992; 90:1952-1957.
35. Inoue M, Kratz G, Haegerstrand A et al. Collagenase expression is rapidly induced in wound edge keratinocytes after acute injury in human skin; persists during healing and stops at re-epithelialization. J Invest Dermatol, 1995; 104:479-483.
36. Grillo HC, Gross J. Collagenolytic activity during mammalian wound repair. Dev Biol 1967; 15:300-317.
37. Saarialho-Kere UK, Kovacs SO, Pentland AP et al. Cell-matrix interactions modulate interstitial collagenase expression by human keratinocytes involved in wound healing. J Clin Invest 1993; 92:2858-2866.
38. Stricklin GP, Li L, Janvic V et al. Localization of mRNAs representing collagenase and Timp in sections of healing human burn wounds. Am J Pathol 1993; 143:1657-1666.
39. Ägren MS, Taplin CJ, Woessner JF et al. Collagenase in wound healing: effect of wound age and type. J Invest Dermatol 1992; 99:709-714.
40. Saarialho-Kere UK,Vaalamo M, Airola K et al. Interstitial collagenase is expressed by keratinocytes that are actively involved in re-epithelialization in blistering skin diseases. J Invest Dermatol 1995; 104:982-988.
41. Airola K, Vaalamo M, Reunala T et al. Enhanced expression of interstitial collagenase, stromelysin-1, and urokinase plasminogen activator in lesions of dermatitis herpetiformis. J Invest Dermatol 1995; 105:184-189.
42. Angel P, Imagawa M, Chiu R et al. 12-0-Tetradecanoyl-phorbol-13-acetate induction of the human collagenase gene is mediated by an inducible enhancer element located in the 5'-flanking region. Mol Cell Biol 1987; 7:2256-2266.
43. Brinckerhoff CE, Plucinska IM, Sheldon LA et al. Half-life of synovial cell collagenase mRNA is modulated by phorbol myristate acetate but not by all-trans-retinoic acid or dexametha-sone. Biochemistry 1986; 25:6378-6384.
44. Lyons JG, Birkedal-Hansen B, Moore WGI et al. Expression of collagen-cleaving matrix-metalloproteinases by keratinocytes. Effect of growth factors and cytokines and of micro-bial mediators. Periodontal disease: pathogens and host immune responses ed. S. Hamada, S.C. Holt, and J. McGhee. 1991 Tokyo: Quitessence Publishing Co. 291-305.
45. Schönthal A, Herrlich P, Rahmsdorf HJ et al. Requirement for fos gene expression in the transcriptional activation of collagenase by other oncogenes and phorbol esters. Cell 1988; 54:325-334.
46. Gutman A and Wasylyk B. The collagenase gene promoter contains a TPA responsive and oncogene-responsive unit encompassing the PEA3 and AP-1 binding sites. Embo J 1990;9:2241-2246.
47. Wasylyk B, Wasylyk C, Flores B et al. The c-ets proto-oncogenes encode transcription factors that cooperate with c-Fos and c-Jun for transcriptional activation. Nature 1990; 346:191-193.
48. Aggeler J, Frisch SM, Werb Z. Changes in cell shape correlate with collagenase gene expression in rabbit synovial fibroblasts. J Cell Biol 1984; 98:1662-1671.
49. Unemori EN, Werb Z. Reorganization of polymerized actin: a possible trigger for induction of procollagenase in fibroblasts cultured in and on collagen gels. J Cell Biol 1986; 103:1021-1031.
50. Werb Z, Hembry M, Murphy G et al. Commitment to expression of the metallopeptidases, collagenase and stromelysin: relationship of inducing events to changes in cytoskeletal architecture. J Cell Biol 1986; 102:697-702.
51. Herrmann G, Wlaschek M, Lange TS et al. UVA irradiation stimulates the synthesis of various matrix-metalloproteinases (MMPs) in cultured human. Exp Dermatol 1993; 2:92-97
52 Vance BA, Kowalski CG, Brinckerhoff CE. Heat shock of rabbit synovial fibroblasts increases expression of mRNA for two metalloproteinases, collagenase and stromelysin. J Cell Biol 1989; 108:2037-2043.
53. Donaldson DJ, Mahan JT, Yang H et al. Integrin and phosphotyrosine expression in normal and migrating newt keratinocytes. Anatomical records, 1995; 241(1):49-58.
54. Larjava H, Salo T, Hapasalmi K et al. Expression of integrins and basement membrane components by wound keratinocytes. J Clin Invest 1993; 92:1425-1435.
55. Cavani A, Zambruno G, Marconi A et al. Distinctive integrin expression in the newly forming epidermis during wound healing in humans. J Invest Dermatol 1993; 101:600-604.
56. Guo M, Kim LT, Akiyama SK et al. Altered procession of integrin receptors during keratinocyte activation. Exp Cell Res 1991; 195:315-322.
57. Lang E, Schafer BM, Eickhoff U et al. Rapid normalization of epidermal integrin expression after allografting of human keratinocytes. J Invest Dermatol 1996; 107:423-427.
58. De Luca M, Pellegrini G, Zambruno G et al. Role of integrins in cell adhesion and polarity in normal keratinocytes and human skin pathologies. J Dermatol, 1994; 21:821-828.
59. Hertle MK, Adams JC, Watt FM. Integrin expression during human epidermal development in vivo and in vitro. Development 1991; 112:193-206.
60. Hertle MK, Kubler M-D, Leigh IM et al. Aberrant integrin expression during epidermal wound healing and in psoriatic epidermis. J Clin Invest 1992; 89:1892-1901.
61. Juhasz I, Murphy GM, Yan H-C et al. Regulation of extracellular matrix proteins and integrin cell substratum adhesion receptors on epithelium during cutaneous wound healing in vivo Am J Pathol 1993; 143:1458-1469.
62. Hergott GJ, Nagai H, Kalnins VI. Inhibition of retinal pigment epithelial cell migration and proliferation with monoclonal antibodies against the beta 1 integrin subunit during wound healing in organ culture. Invest Ophthalmol Vis Science, 1993; 34(9):2761-2768.
63. Pilcher BK, Dumin JA, Sudbeck BD et al. The activity of collagenase-1 is required for keratinocyte migration on type I collagen matrix. J Cell Biol 1997; 137:1-13.
64. Tremble P, Chiquet-Ehrismann R, Werb Z. The extracellular matrix ligands fibronectin and tenascin collaborate in regulating collagenase gene expression in fibroblasts. Mol Biol Cell 1994; 5(4):439-453.
65. Fava RA, McClure DB. Fibronectin-associated transforming growth factor. J Cell Physiol 1987; 131:184 -189.
66. Woodley DT, Kalebec T, Banes AJ et al. Adult human keratinocytes migrating over nonvi-able dermal collagen produce collagenolytic enzymes that degrade type I and type IV collagen. J Invest Dermatol 1986; 86:418-423.
67. Sudbeck BD, Parks WC, Welgus HG et al. Collagen-stimulated induction of keratinocyte collagenase is mediated via tyrosine kinase C activities. J Biol Chem 1994; 269:30022-30029.
68. Petersen MJ, Woodley DT, Stricklin GP et al. Enhanced synthesis of collagenase by human keratinocytes cultured on type I or type IV collagen. J Invest Dermatol 1990; 94:341-346.
69. Petersen MJ,Woodley DT, Stricklin GP et al. Synthesis and regulation of keratinocyte collagenase. Matrix 1992; 1:192-197.
70. Werb Z, Tremble PM, Behrendtsen O et al. Signal transduction through the fibronectin receptor induces collagenase and stromelysin gene expression. J Cell Biol 1989; 109:877-888.
71. Kapila YL, Kapila S. Johnson PW. Fibronectin and fibronectin fragments modulate the expression of proteinases and proteinase inhibitors in human periodontal ligament cells. Matrix Biology 1996; 15:251-261.
72. Kupper T. Interleukin-1 and other human keratinocyte cytokines: molecular and functional characterization. Adv Dermatol 1988; 3:293-301.
73. Ansel, J, Perry P, Brown J et al. Cytokine modulation of keratinocyte cytokines. J Invest Dermatol 1990; 94:101S-107S.
74. Laato N, Niinikskij J, Gerdin B et al. Stimulation of wound healing by epidermal growth factor. Ann Surg 1986; 203:379-381.
75. Nanney LB. Epidermal and dermal effects of epidermal growth factor during wound repair. J Invest Dermatol 1990; 94:624-629.
76. Kerr LD, Holt JT, Matrisian L. Growth factors regulate transin gene expression by c-fos-dependent and c-fos-independent pathways. Science 1988; 242:1424-1427.
77. Moolenaar WH, Bierman AJ, Tilly BC et al. A point mutation at the ATP-binding site of the EGF-receptor abolishes signal transduction. Mol Cell Biol 1988; 7:4568-4571.
78. King LE, Gates RE, Stoschek CM et al. The EGF/TGFa receptor in skin. J Invest Dermatol 1990; 94:164S-170S.
79. Pilcher BK, Gaither-Ganim J, Parks WC et al. Type-I collagen-mediated induction of keratinocyte collagenase-1 requires an epidermal growth factor receptor autocrine loop. J Invest Dermatol 1997;108: 548.
80. Prescott JN, Troccoli, N, Biswas C. Coordinate increase in collagenase mRNA and enzyme levels in human fibroblasts treated with the tumor cell factor, TCSF. Biochem Int 1989; 19:257-266.
81. Biswas C, Zhang Y, DeCastro et al. The human tumor cell-derived collagenase stimulatory factor (renamed EMMPRIN) is a member of the immunoglobulin superfamily. Cancer Res 1995; 55:434-439.
82. DeCastro R, Zhang Y, Guo H et al. Human keratinocytes express EMMPRIN, an extracellular matrix proteinase inducer. J Invest Dermatol 1996; 106:1260-1263.
83. Kataoka H, DeCatro R, Zucker S et al. The tumor-cell derived collagenase stimulatory factor, TCSF, increases expression of interstitial collagenase, stromelysin and 72 kda gelatinase. Cancer Res 1993; 53:3154-3158.
84. Nagase H, Ogata Y, Suzuki K et al. Substrate specificities and activation mechanisms of matrix metalloproteinases. Biochem Soc Trans 1991; 19:715-718.
85. Romer J, Lund LR, Ralfkiaer E et al. Differential expression of urokinase-type plasminogen activator and its type-1 inhibitor during healing of mouse skin wounds. J Invest Dermatol 1991; 97:803-811.
86. Romer J, Bugge TH, Pyke C et al. Impaired wound healing in mice with a disrupted plas-minogen gene. Nature Medicine 1996; 2:287-292.
87. Stacey MC, Burnand KG, Mahmoud-Alexandroni M et al. Tissue and urokinase plasmino-gen activators in the environs of venous and ischaemic leg ulcers. Brit J Surgery 1993; 80:596-599.
88. Sato H, Takino T, Okada Y et al. A matrix metalloproteinase expressed on the surface of invasive tumor cells. Nature 1994; 370:61-65.
89. Takino T, Sato H, Shinagawa A et al. Identification of the second membrane-type matrix metalloproteinase (MT-MMP-2) gene from a human placenta cDNA library. MT-MMPs form a unique membrane-type subclass in the MMP family. J Biol Chem 1995; 270(39):23013-23020.
90. Will H, Hinzmann B. cDNA sequence and mRNA tissue distribution of a novel human matrix metalloproteinase with a potential transmembrane segment. Eur J Bioch 1995; 231:602-608.
91. Strongin AY, Collier I, Bannikov G et al. Mechanism of cell surface activation of 72-kDa type IV collagenase. Isolation of the active form of the membrane metalloproteinase. J Biol Chem 1995; 270:5331-5338.
92. Puente XS, Pendas AM, Llano E et al. Molecular cloning of a novel membrane-type matrix metalloproteinase from human breast carcinoma. Cancer Res 1996; 56(5).
93. Lohi J, Lehti K, Westermarck J et al. Regulation of membrane-type matrix metalloproteinase-1 expression by growth factors and phorbol 12-myristate 13-acetate. Eur J Biochem 1996; 239:239-247.
94. Okada A, Bellocq JP, Rouyer N et al. Membrane-type matrix metalloproteinase (MT-MMP) gene is expressed in stromal cells of human colon, breast and head and neck carcinomas. Proc Natl Acad Sci 1995; 92:2730-2734.
95. Saarialho-Kere U. Patterns of matrix metalloproteinase and TIMP expression in chronic ulcers. Arch Dermatol Res 1998; 290:47-54.
96. Saarialho-Kere UK, Vaalamo M, Puolakkainen P et al. Enhanced expression of matrilysin, collagenase, and stromelysin-1 in gastrointestinal ulcers. Am J Pathol 1996; 148:519-526.
Was this article helpful?
Learning About 10 Ways Fight Off Cancer Can Have Amazing Benefits For Your Life The Best Tips On How To Keep This Killer At Bay Discovering that you or a loved one has cancer can be utterly terrifying. All the same, once you comprehend the causes of cancer and learn how to reverse those causes, you or your loved one may have more than a fighting chance of beating out cancer.