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. 1996 Sep 15;98(6):1389–1399. doi: 10.1172/JCI118926

Constitutive and inducible expression of SKALP/elafin provides anti-elastase defense in human epithelia.

R Pfundt 1, F van Ruissen 1, I M van Vlijmen-Willems 1, H A Alkemade 1, P L Zeeuwen 1, P H Jap 1, H Dijkman 1, J Fransen 1, H Croes 1, P E van Erp 1, J Schalkwijk 1
PMCID: PMC507565  PMID: 8823304

Abstract

Skin-derived antileukoproteinase (SKALP), also known as elafin, is a serine proteinase inhibitor first discovered in keratinocytes from hyperproliferative human epidermis. In addition to the proteinase inhibiting domain which is directed against polymorphonuclear leukocyte (PMN) derived enzymes such as elastase and proteinase 3, SKALP contains multiple transglutaminase (TGase) substrate domains which enable crosslinking to extracellular and cell envelope proteins. Here we show that SKALP is constitutively expressed in several epithelia that are continuously subjected to inflammatory stimuli, such as the oral cavity and the vagina where it co-localizes with type 1 TGase. All epithelia from sterile body cavities are negative for SKALP. In general, stratified squamous epithelia are positive, whereas pseudostratified epithelia, simple/glandular epithelia and normal epidermis are negative. SKALP was found in fetal tissues of the oral cavity from 17 wk gestation onwards where it continued to be expressed up to adult life. Remarkably, in fetal epidermis SKALP was found from week 28 onwards, but was downregulated to undetectable levels in neonatal skin within three months, suggesting a role during pregnancy in feto-maternal interactions or in the early maturation phase of the epidermis. Immunoelectron microscopy revealed the presence of SKALP in secretory vesicles including the lamellar granules. In culture models for epidermal keratinocytes we found that expression of the endogenous SKALP gene provided protection against cell detachment caused by purified elastase or activated PMNs. Addition of exogenous recombinant SKALP fully protected the keratinocytes against PMN-dependent detachment whereas superoxide dismutase and catalase were only marginally effective. These findings strongly suggest that the constitutive expression of SKALP in squamous epithelia, and the inducible expression in epidermis participate in the control of epithelial integrity, by inhibiting PMN derived proteinases.

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Selected References

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  1. Alkemade J. A., Molhuizen H. O., Ponec M., Kempenaar J. A., Zeeuwen P. L., de Jongh G. J., van Vlijmen-Willems I. M., van Erp P. E., van de Kerkhof P. C., Schalkwijk J. SKALP/elafin is an inducible proteinase inhibitor in human epidermal keratinocytes. J Cell Sci. 1994 Aug;107(Pt 8):2335–2342. doi: 10.1242/jcs.107.8.2335. [DOI] [PubMed] [Google Scholar]
  2. Badinga L., Michel F. J., Fields M. J., Sharp D. C., Simmen R. C. Pregnancy-associated endometrial expression of antileukoproteinase gene is correlated with epitheliochorial placentation. Mol Reprod Dev. 1994 Aug;38(4):357–363. doi: 10.1002/mrd.1080380402. [DOI] [PubMed] [Google Scholar]
  3. Calkins C. C., Sloane B. F. Mammalian cysteine protease inhibitors: biochemical properties and possible roles in tumor progression. Biol Chem Hoppe Seyler. 1995 Feb;376(2):71–80. [PubMed] [Google Scholar]
  4. Campbell E. J., Campbell M. A. Pericellular proteolysis by neutrophils in the presence of proteinase inhibitors: effects of substrate opsonization. J Cell Biol. 1988 Mar;106(3):667–676. doi: 10.1083/jcb.106.3.667. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Dale B. A., Holbrook K. A., Kimball J. R., Hoff M., Sun T. T. Expression of epidermal keratins and filaggrin during human fetal skin development. J Cell Biol. 1985 Oct;101(4):1257–1269. doi: 10.1083/jcb.101.4.1257. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Fuchs E. Epidermal differentiation: the bare essentials. J Cell Biol. 1990 Dec;111(6 Pt 2):2807–2814. doi: 10.1083/jcb.111.6.2807. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Katayama H., Hase T., Yaoita H. Detachment of cultured normal human keratinocytes by contact with TNF alpha-stimulated neutrophils in the presence of platelet-activating factor. J Invest Dermatol. 1994 Aug;103(2):187–190. doi: 10.1111/1523-1747.ep12392711. [DOI] [PubMed] [Google Scholar]
  8. Mansbridge J. N., Knapp A. M. Changes in keratinocyte maturation during wound healing. J Invest Dermatol. 1987 Sep;89(3):253–263. doi: 10.1111/1523-1747.ep12471216. [DOI] [PubMed] [Google Scholar]
  9. Molhuizen H. O., Alkemade H. A., Zeeuwen P. L., de Jongh G. J., Wieringa B., Schalkwijk J. SKALP/elafin: an elastase inhibitor from cultured human keratinocytes. Purification, cDNA sequence, and evidence for transglutaminase cross-linking. J Biol Chem. 1993 Jun 5;268(16):12028–12032. [PubMed] [Google Scholar]
  10. Molhuizen H. O., Zeeuwen P. L., Olde Weghuis D., Geurts van Kessel A., Schalkwijk J. Assignment of the human gene encoding the epidermal serine proteinase inhibitor SKALP (PI3) to chromosome region 20q12-->q13. Cytogenet Cell Genet. 1994;66(2):129–131. doi: 10.1159/000133683. [DOI] [PubMed] [Google Scholar]
  11. Murphy G., Docherty A. J. The matrix metalloproteinases and their inhibitors. Am J Respir Cell Mol Biol. 1992 Aug;7(2):120–125. doi: 10.1165/ajrcmb/7.2.120. [DOI] [PubMed] [Google Scholar]
  12. Nakamura T. Y., Yamamoto I., Nishitani H., Matozaki T., Suzuki T., Wakabayashi S., Shigekawa M., Goshima K. Detachment of cultured cells from the substratum induced by the neutrophil-derived oxidant NH2Cl: synergistic role of phosphotyrosine and intracellular Ca2+ concentration. J Cell Biol. 1995 Oct;131(2):509–524. doi: 10.1083/jcb.131.2.509. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Nara K., Ito S., Ito T., Suzuki Y., Ghoneim M. A., Tachibana S., Hirose S. Elastase inhibitor elafin is a new type of proteinase inhibitor which has a transglutaminase-mediated anchoring sequence termed "cementoin". J Biochem. 1994 Mar;115(3):441–448. doi: 10.1093/oxfordjournals.jbchem.a124357. [DOI] [PubMed] [Google Scholar]
  14. Nonomura K., Yamanishi K., Yasuno H., Nara K., Hirose S. Up-regulation of elafin/SKALP gene expression in psoriatic epidermis. J Invest Dermatol. 1994 Jul;103(1):88–91. doi: 10.1111/1523-1747.ep12391802. [DOI] [PubMed] [Google Scholar]
  15. Owen C. A., Campbell M. A., Sannes P. L., Boukedes S. S., Campbell E. J. Cell surface-bound elastase and cathepsin G on human neutrophils: a novel, non-oxidative mechanism by which neutrophils focus and preserve catalytic activity of serine proteinases. J Cell Biol. 1995 Nov;131(3):775–789. doi: 10.1083/jcb.131.3.775. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Perlmutter D. H., Travis J., Punsal P. I. Elastase regulates the synthesis of its inhibitor, alpha 1-proteinase inhibitor, and exaggerates the defect in homozygous PiZZ alpha 1 PI deficiency. J Clin Invest. 1988 Jun;81(6):1774–1780. doi: 10.1172/JCI113519. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Poumay Y., Pittelkow M. R. Cell density and culture factors regulate keratinocyte commitment to differentiation and expression of suprabasal K1/K10 keratins. J Invest Dermatol. 1995 Feb;104(2):271–276. doi: 10.1111/1523-1747.ep12612810. [DOI] [PubMed] [Google Scholar]
  18. Reibel J., Clausen H., Dale B. A., Thacher S. M. Immunohistochemical analysis of stratum corneum components in oral squamous epithelia. Differentiation. 1989 Sep;41(3):237–244. doi: 10.1111/j.1432-0436.1989.tb00752.x. [DOI] [PubMed] [Google Scholar]
  19. Rheinwald J. G., Green H. Serial cultivation of strains of human epidermal keratinocytes: the formation of keratinizing colonies from single cells. Cell. 1975 Nov;6(3):331–343. doi: 10.1016/s0092-8674(75)80001-8. [DOI] [PubMed] [Google Scholar]
  20. Saheki T., Ito F., Hagiwara H., Saito Y., Kuroki J., Tachibana S., Hirose S. Primary structure of the human elafin precursor preproelafin deduced from the nucleotide sequence of its gene and the presence of unique repetitive sequences in the prosegment. Biochem Biophys Res Commun. 1992 May 29;185(1):240–245. doi: 10.1016/s0006-291x(05)80981-7. [DOI] [PubMed] [Google Scholar]
  21. Sallenave J. M., Shulmann J., Crossley J., Jordana M., Gauldie J. Regulation of secretory leukocyte proteinase inhibitor (SLPI) and elastase-specific inhibitor (ESI/elafin) in human airway epithelial cells by cytokines and neutrophilic enzymes. Am J Respir Cell Mol Biol. 1994 Dec;11(6):733–741. doi: 10.1165/ajrcmb.11.6.7946401. [DOI] [PubMed] [Google Scholar]
  22. Sallenave J. M., Silva A. Characterization and gene sequence of the precursor of elafin, an elastase-specific inhibitor in bronchial secretions. Am J Respir Cell Mol Biol. 1993 Apr;8(4):439–445. doi: 10.1165/ajrcmb/8.4.439. [DOI] [PubMed] [Google Scholar]
  23. Schalkwijk J., Chang A., Janssen P., De Jongh G. J., Mier P. D. Skin-derived antileucoproteases (SKALPs): characterization of two new elastase inhibitors from psoriatic epidermis. Br J Dermatol. 1990 May;122(5):631–641. doi: 10.1111/j.1365-2133.1990.tb07285.x. [DOI] [PubMed] [Google Scholar]
  24. Schalkwijk J., de Roo C., de Jongh G. J. Skin-derived antileukoproteinase (SKALP), an elastase inhibitor from human keratinocytes. Purification and biochemical properties. Biochim Biophys Acta. 1991 Feb 22;1096(2):148–154. doi: 10.1016/0925-4439(91)90053-c. [DOI] [PubMed] [Google Scholar]
  25. Schalkwijk J., van Vlijmen I. M., Alkemade J. A., de Jongh G. J. Immunohistochemical localization of SKALP/elafin in psoriatic epidermis. J Invest Dermatol. 1993 Apr;100(4):390–393. doi: 10.1111/1523-1747.ep12471990. [DOI] [PubMed] [Google Scholar]
  26. Schrijver G., Schalkwijk J., Robben J. C., Assmann K. J., Koene R. A. Antiglomerular basement membrane nephritis in beige mice. Deficiency of leukocytic neutral proteinases prevents the induction of albuminuria in the heterologous phase. J Exp Med. 1989 Apr 1;169(4):1435–1448. doi: 10.1084/jem.169.4.1435. [DOI] [PMC free article] [PubMed] [Google Scholar]
  27. Steinert P. M., Marekov L. N. The proteins elafin, filaggrin, keratin intermediate filaments, loricrin, and small proline-rich proteins 1 and 2 are isodipeptide cross-linked components of the human epidermal cornified cell envelope. J Biol Chem. 1995 Jul 28;270(30):17702–17711. doi: 10.1074/jbc.270.30.17702. [DOI] [PubMed] [Google Scholar]
  28. Van Ruissen F., de Jongh G. J., Zeeuwen P. L., Van Erp P. E., Madsen P., Schalkwijk J. Induction of normal and psoriatic phenotypes in submerged keratinocyte cultures. J Cell Physiol. 1996 Aug;168(2):442–452. doi: 10.1002/(SICI)1097-4652(199608)168:2<442::AID-JCP23>3.0.CO;2-3. [DOI] [PubMed] [Google Scholar]
  29. Vogelmeier C., Hubbard R. C., Fells G. A., Schnebli H. P., Thompson R. C., Fritz H., Crystal R. G. Anti-neutrophil elastase defense of the normal human respiratory epithelial surface provided by the secretory leukoprotease inhibitor. J Clin Invest. 1991 Feb;87(2):482–488. doi: 10.1172/JCI115021. [DOI] [PMC free article] [PubMed] [Google Scholar]
  30. Watt F. M. Terminal differentiation of epidermal keratinocytes. Curr Opin Cell Biol. 1989 Dec;1(6):1107–1115. doi: 10.1016/s0955-0674(89)80058-4. [DOI] [PubMed] [Google Scholar]
  31. Weiss R. A., Eichner R., Sun T. T. Monoclonal antibody analysis of keratin expression in epidermal diseases: a 48- and 56-kdalton keratin as molecular markers for hyperproliferative keratinocytes. J Cell Biol. 1984 Apr;98(4):1397–1406. doi: 10.1083/jcb.98.4.1397. [DOI] [PMC free article] [PubMed] [Google Scholar]
  32. Weiss S. J. Tissue destruction by neutrophils. N Engl J Med. 1989 Feb 9;320(6):365–376. doi: 10.1056/NEJM198902093200606. [DOI] [PubMed] [Google Scholar]
  33. Wiedow O., Lüademann J., Utecht B. Elafin is a potent inhibitor of proteinase 3. Biochem Biophys Res Commun. 1991 Jan 15;174(1):6–10. doi: 10.1016/0006-291x(91)90476-n. [DOI] [PubMed] [Google Scholar]
  34. Wiedow O., Schröder J. M., Gregory H., Young J. A., Christophers E. Elafin: an elastase-specific inhibitor of human skin. Purification, characterization, and complete amino acid sequence. J Biol Chem. 1990 Sep 5;265(25):14791–14795. [PubMed] [Google Scholar]
  35. Zhang M., Zou Z., Maass N., Sager R. Differential expression of elafin in human normal mammary epithelial cells and carcinomas is regulated at the transcriptional level. Cancer Res. 1995 Jun 15;55(12):2537–2541. [PubMed] [Google Scholar]
  36. van Duijnhoven J. L., Schalkwijk J., Kranenborg M. H., van Vlijmen-Willems I. M., Groeneveld A., van Erp P. E., Timmer E. D., de Jongh G. J., van de Ven W. J. MON-150, a versatile monoclonal antibody against involucrin: characterization and applications. Arch Dermatol Res. 1992;284(3):167–172. doi: 10.1007/BF00372711. [DOI] [PubMed] [Google Scholar]
  37. van Ruissen F., van Erp P. E., de Jongh G. J., Boezeman J. B., van de Kerkhof P. C., Schalkwijk J. Cell kinetic characterization of growth arrest in cultured human keratinocytes. J Cell Sci. 1994 Aug;107(Pt 8):2219–2228. doi: 10.1242/jcs.107.8.2219. [DOI] [PubMed] [Google Scholar]

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