Levels and molecular forms of MMP-7 (matrilysin-1) and MMP-8 (collagenase-2) in diseased human peri-implant sulcular fluid Marjo Kivelä-Rajamäki 1 ,Päivi Maisi 2 ,RaviSrinivas 1 ,Taina Tervahartiala 1 ,OlliTeronen 1 ,Ville Husa 1 ,TuulaSalo 1,3 ,TimoSorsa 1 1 Department of Oral and Maxillofacial Diseases, Helsinki University Central Hospital, Institute of Dentistry, University of Helsinki; The Orton Research Institute and The Orthopedic Hospital of Invalid Foundation, Helsinki, Finland, 2 Department of Clinical Sciences, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland, 3 Department of Oral Diagnostics and Medicine, University of Oulu and Oulu University Central Hospital, Oulu, Finland Kivela ¨-Rajama ¨ki M, Maisi P, Srinivas R, Tervahartiala T, Teronen O, Husa V, Salo T, Sorsa T. Levels and molecular forms of MMP-7 (matrilysin-1) and MMP-8 (collagenase-2) in diseased human peri-implant sulcular fluid. J Periodont Res 2003; 38; 583–590. Ó Blackwell Munksgaard, 2003. Objectives: Matrix metalloproteinases (MMPs) play crucial role in various tissue destructive inflammatory processes by degrading almost all peri-cellular and basement membrane components. MMP-8 (collagenase-2) is the major MMP in periodontitis. MMP-7 (matrilysin-1), in addition to its ability to degrade matrix and basement membrane components, activates other latent pro-MMPs and defensins, host cell-derived antimicrobial cryptidins. The aim of the present study was to characterize the relationship, levels and molecular forms of MMP-8 and MMP-7 in diseased peri-implant sulcular fluid (PISF). Materials and methods: Seventy-two human dental implant fluid samples were collected with filter paper strips from peri-implant sulci from healthy and untreated diseased implant sites. Gingival index (GI) and/or bone resorption (BR) were also recorded. Western immunoblot method with polyclonal anti-human- MMP-8 and monoclonal anti-human-MMP-7 antibodies was used, and immunoreactivities were quantified with computer scanning program. The effects of MMP inhibitors (doxycycline, chemically modified tetracycline-3, clodronate, CTT-peptide and marimastat) were studied on the activity of recombinant human matrilysin-1 (MMP-7) using b-casein degradation assay. Results: The levels of active forms of MMP-8 and MMP-7 were significantly elevated in diseased PISF in relation to healthy PISF. Furthermore, MMP-8 and MMP-7 levels correlated significantly to each other and GI. MMP-8 was present not only as bands corresponding to 75-kDa polymorphonuclear leukocyte (PMN) -type pro- and 65-kDa active forms, but also as 55-kDa non-PMN-type pro- and 45-kDa active forms. Immunoreactivities > 80 kDa most likely repre- sented dimeric and/or inhibitor-bound MMP-8 complexes and the low molecular weight (< 30 kDa) species were apparently degraded fragments. In diseased PISF, 19–21-kDa active MMP-7 and 28–30-kDa pro-MMP-7 species were detected, and the active 19–21-kDa forms of MMP-7 predominated in diseased PISF. Dox- ycycline (50 lM and 250 lM), chemically modified non-antimicrobial tetracycline (CMT-3) (50 lM and 100 lM), clodronate (a bisphosphonate, 20 lM and 500 lM) and the cyclic CTT (CTTHWGFTLC)-peptide (125 lM and 250 lM), all known broad-spectrum or selective MMP-inhibitors, did not inhibit the activity of human recombinant MMP-7; only marimastat (1 lM and 5 lM) inhibited MMP-7. Marjo Kivelä-Rajamäki, DDS, Institute of Dentistry, Research Laboratory, 2nd floor, Biomedicum, PL 63 (Haartmaninkatu 8), 00014 Helsinki University, Finland Tel: +358 9 191 25436 Fax: +358 9 191 25371 e-mail: marjo.kivela@helsinki.fi Key words: collagenase-2;implants;matrilysin-1; matrix metalloproteinases; peri-implantitis Accepted for publication May 6, 2003 J Periodont Res 2003; 38; 583–590 Printed in the UK. All rights reserved Copyright Ó Blackwell Munksgaard Ltd JOURNAL OF PERIODONTAL RESEARCH