Levels and molecular forms of MMP-7 (matrilysin-1) and MMP-8 (collagenase-2) in diseased human peri-implant sulcular fluid.
OBJECTIVE
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).


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 beta-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 represented 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. Doxycycline (50 micro m and 250 micro m), chemically modified non-antimicrobial tetracycline (CMT-3) (50 micro m and 100 micro m), clodronate (a bisphosphonate, 20 micro m and 500 micro m) and the cyclic CTT (CTTHWGFTLC)-peptide (125 micro m and 250 micro m), all known broad-spectrum or selective MMP-inhibitors, did not inhibit the activity of human recombinant MMP-7; only marimastat (1 micro m and 5 micro m) inhibited MMP-7.


CONCLUSIONS
Increased immunoreactivities of the active MMP-8 and MMP-7 species in PISF from diseased peri-implantitis lesions eventually reflect the stage and course of peri-implantitis; MMP-7 may potentially act as MMP-8 and defensin activator in diseased PISF.


CONCLUSIONS
The elevated levels of MMP-8 and matrilysin-1/MMP-7 were identified in active forms in diseased PISF, but MMP-7 was less prominent. MMP inhibitors, potential future tissue protective drugs, seemingly do not interfere with the defensive antibacterial action of MMP-7.
Kivelä-Rajamäki
Marjo
M
Department of Oral and Maxillofacial Diseases, Helsinki University Central Hospital, Institute of Dentistry, University of Helsinki, Helsinki, Finland. marjo.kivela@helsinki.fi
Maisi
Päivi
P
Srinivas
Ravi
R
Tervahartiala
Taina
T
Teronen
Olli
O
Husa
Ville
V
Salo
Tuula
T
Sorsa
Timo
T
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016301:Alveolar Bone Loss / Q000201:enzymology; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D004002:Clodronic Acid / Q000494:pharmacology; D015921:Dental Implants; D004318:Doxycycline / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D005883:Gingival Crevicular Fluid / Q000201:enzymology*; D006801:Humans; D006877:Hydroxamic Acids / Q000494:pharmacology; D008297:Male; D020783:Matrix Metalloproteinase 7 / Q000032:analysis* / Q000145:classification; D020784:Matrix Metalloproteinase 8 / Q000032:analysis* / Q000145:classification; D061965:Matrix Metalloproteinase Inhibitors; D008875:Middle Aged; D010456:Peptides, Cyclic / Q000494:pharmacology; D010512:Periodontal Index; D010518:Periodontitis / Q000201:enzymology*; D013754:Tetracyclines / Q000494:pharmacology
D000900:Anti-Bacterial Agents; C415426:CTTHWGFTLC peptide; D015921:Dental Implants; D004791:Enzyme Inhibitors; D006877:Hydroxamic Acids; D061965:Matrix Metalloproteinase Inhibitors; D010456:Peptides, Cyclic; D013754:Tetracyclines; C117155:tetracycline CMT-3; D004002:Clodronic Acid; C100342:marimastat; D020783:Matrix Metalloproteinase 7; D020784:Matrix Metalloproteinase 8; D004318:Doxycycline