A novel chemically modified curcumin reduces inflammation-mediated connective tissue breakdown in a rat model of diabetes: periodontal and systemic effects.

BACKGROUND AND OBJECTIVE: Periodontal disease is the most common chronic inflammatory disease known to mankind (and the major cause of tooth loss in the adult population) and has also been linked to various systemic diseases, particularly diabetes mellitus. Based on the literature linking periodontal disease with diabetes in a "bidirectional manner", the objectives of the current study were to determine: (i) the effect of a model of periodontitis, complicated by diabetes, on mechanisms of tissue breakdown including bone loss; and (ii) the response of the combination of this local and systemic phenotype to a novel pleiotropic matrix metalloproteinase inhibitor, chemically modified curcumin (CMC) 2.24. MATERIAL AND METHODS: Diabetes was induced in adult male rats by intravenous injection of streptozotocin (nondiabetic rats served as controls), and Escherichia coli endotoxin (lipopolysaccharide) was repeatedly injected into the gingiva to induce periodontitis. CMC 2.24 was administered by oral gavage (30 mg/kg) daily; untreated diabetic rats received vehicle alone. After 3 wk of treatment, the rats were killed, and gingiva, jaws, tibia and skin were collected. The maxillary jaws and tibia were dissected and radiographed. The gingival tissues of each experimental group (n = 6 rats/group) were pooled, extracted, partially purified and, together with individual skin samples, analyzed for matrix metalloproteinase (MMP)-2 and MMP-9 by gelatin zymography; MMP-8 was analyzed in gingival and skin tissue extracts, and in serum, by western blotting. The levels of three bone-resorptive cytokines [interleukin (IL)-1ß, IL-6 and tumor necrosis factor-α], were measured in gingival tissue extracts and serum by ELISA. RESULTS: Systemic administration of CMC 2.24 to diabetic rats with endotoxin-induced periodontitis significantly inhibited alveolar bone loss and attenuated the severity of local and systemic inflammation. Moreover, this novel tri-ketonic phenylaminocarbonyl curcumin (CMC 2.24) appeared to reduce the pathologically excessive levels of inducible MMPs to near-normal levels, but appeared to have no significant effect on the constitutive MMPs required for physiologic connective tissue turnover. In addition to the beneficial effects on periodontal disease, induced both locally and systemically, CMC 2.24 also favorably affected extra-oral connective tissues, skin and skeletal bone. CONCLUSION: This study supports our hypothesis that CMC 2.24 is a potential therapeutic pleiotropic MMP inhibitor, with both intracellular and extracellular effects, which reduces local and systemic inflammation and prevents hyperglycemia- and bacteria-induced connective tissue destruction.

Serum bone biomarkers and oral/systemic bone loss in humans.

UNLABELLED: We recently reported that subantimicrobial-dose doxycycline (SDD) significantly reduced serum bone-resorption biomarkers in subgroups of post-menopausal women. We hypothesize that changes in serum bone biomarkers are associated not only with systemic bone mineral density (BMD) changes, but also with alveolar bone changes over time. One hundred twenty-eight eligible post-menopausal women with periodontitis and systemic osteopenia were randomly assigned to receive SDD or placebo tablets twice daily for two years, adjunctive to periodontal maintenance. Sera were analyzed for bone biomarkers. As expected, two-year changes in a serum bone biomarker were significantly associated with systemic BMD loss at the lumbar spine (osteocalcin, bone-turnover biomarker, p = 0.0002) and femoral neck (osteocalcin p = 0.0025). Two-year changes in serum osteocalcin and serum pyridinoline-crosslink fragment of type I collagen (ICTP; bone-resorption biomarker) were also significantly associated with alveolar bone density loss (p < 0.0001) and alveolar bone height loss (p = 0.0008), respectively. Thus, we have shown that serum bone biomarkers are associated with not only systemic BMD loss, but with alveolar bone loss as well. CLINICAL TRIAL REGISTRATION INFORMATION: Protocol registered at ClinicalTrials.gov, NCT00066027.

Doxycycline effects on serum bone biomarkers in post-menopausal women.

We previously demonstrated that subantimicrobial-dose-doxycycline (SDD) treatment of post-menopausal osteopenic women significantly reduced periodontal disease progression, and biomarkers of collagen destruction and bone resorption locally in periodontal pockets, in a double-blind placebo-controlled clinical trial. We now hypothesize that SDD may also improve biomarkers of bone loss systemically in the same women, consistent with previous studies on tetracyclines (e.g., doxycycline) in organ culture and animal models of bone-deficiency disease. 128 post-menopausal osteopenic women with chronic periodontitis randomly received SDD or placebo tablets daily for 2 years adjunctive to periodontal maintenance therapy every 3-4 months. Blood was collected at baseline and at one- and two-year appointments, and sera were analyzed for bone resorption and bone formation/turnover biomarkers. In subsets of the study population, adjunctive SDD significantly reduced serum biomarkers of bone resorption (biomarkers of bone formation were unaffected), consistent with reduced risk of future systemic bone loss in these post-menopausal women not yet on anti-osteoporotic drugs.

Chemically modified tetracycline (CMT)-3 inhibits histamine release and cytokine production in mast cells: possible involvement of protein kinase C.

OBJECTIVE: To find novel inhibitors of mast cell function we have studied the effect of a potent, non-antimicrobial, chemically modified tetracycline, CMT-3 or COL-3, on key functions of mast cells. METHODS AND RESULTS: In the presence of 25 microM CMT-3, the 48/80-induced histamine release from rat serosal mast cells was inhibited significantly, to 43.0 +/- 7.3% of control. Similarly, the activation-induced secretion of TNF-alpha and IL-8 by HMC-1 cells were decreased in the presence of 25 microM CMT-3 to 13.5 +/- 4.1% and 9.7 +/- 1.1% of control, respectively. CMT-3 did not cause intracellular accumulation of TNF-alpha but instead it reduced the expression of TNF-alpha mRNA in HMC-1 cells. Moreover, CMT-3 was found to significantly inhibit the protein kinase C (PKC) activity with IC(50) value of 31 microM. CMT-3 inhibited effectively both human recombinant PKCalpha and PKCdelta isoforms. In comparison to doxycycline, CMT-3 was more effective as an inhibitor of both cytokine production and PKC activity. CONCLUSIONS: Considering the central role of PKC in mast cell activation, PKC inhibition could, at least partially, explain the observed inhibitory effects of CMT-3. The inhibition of the key proinflammatory functions of mast cells by CMT-3 suggests its potential clinical usefulness in the treatment of allergic and inflammatory disorders.

Inhibition of proteolytic, serpinolytic, and progelatinase-b activation activities of periodontopathogens by doxycycline and the non-antimicrobial chemically modified tetracycline derivatives.

BACKGROUND: Tetracyclines, particularly doxycycline (Doxy), and their non-antimicrobial chemically-modified derivatives (CMTs) inhibit the activities of human matrix metalloproteinases (MMPs), and reduce the severity and progression of periodontal disease in animal models and humans. In this study, the effects of Doxy and CMT-1, -3, and -5 on proteolytic, serpinolytic, and progelatinase-B activation activities of potent periodontopathogens were studied. METHODS: The effect of Doxy and CMTs (0.5 to 50 microM) on proteolytic activities were investigated by incubating bacteria with chromogenic substrates or human serum albumin. A collagenolytic fraction of Porphyromonas gingivalis was used to evaluate the effect of these substances on collagenolytic (type I collagen) and serpinolytic (alpha1-proteinase inhibitor) activities. Lastly, the effect of Doxy on progelatinase-B (pro-MMP-9) activation by purified proteinases from P. gingivalis and Treponema denticola was investigated by SDS-PAGE/Western immunoblotting. RESULTS: Doxy and CMTs, except CMT-5 which lacks the structural elements required for cation chelation, inhibited Arg- and Lys-gingipain activities as well as collagenolytic activity of P. gingivalis. Doxy and CMTs did not markedly affect the chymotrypsin-like activity of T. denticola but inhibited its trypsin-like activity. In addition, degradation of human serum albumin by cells of P. gingivalis and T. denticola was strongly inhibited by Doxy and CMT-1. Doxy and CMT-1 also inhibited the inactivation of alpha1-proteinase inhibitor (serpinolytic activity) by a collagenolytic fraction of P. gingivalis. Lastly, Doxy prevented the latent to active conversion of human neutrophil progelatinase-B (pro-MMP-9) by Arg-gingipains A/B of P. gingivalis but not by the chymotrypsin-like proteinase of T. denticola. CONCLUSIONS: Data from this study suggest that Doxy and CMTs have the potential to inhibit the periodontopathogenic bacterial proteinases, which contribute to tissue destruction cascades during periodontitis directly and indirectly by triggering the host response.

A combination of a chemically modified doxycycline and a bisphosphonate synergistically inhibits endotoxin-induced periodontal breakdown in rats.

BACKGROUND: Chemically modified non-antimicrobial tetracyclines (CMTs) have been shown to inhibit pathologically elevated collagenase (and other matrix metalloproteinase, MMP) activity and bone resorption in vivo and in vitro. METHODS: In the current study, suboptimal doses of CMT-8 (a non-antimicrobial chemically modified doxycycline) and a bisphosphonate (clodronate, an anti-bone resorption compound) were administered daily, either as a single agent or as a combination therapy, to rats with experimental periodontitis induced by repeated injection of bacterial endotoxin (LPS) into the gingiva. At the end of the 1-week protocol, the gingival tissues were dissected, extracted, and the extracts analyzed for MMPs (collagenases and gelatinases) and for elastase, and the defleshed jaws were morphometrically analyzed for alveolar bone loss. RESULTS: LPS injection significantly (P<0.001) increased alveolar bone loss and increased collagenase (MMP-8), gelatinase (MMP-9), and elastase activities. Treatment of the LPS-injected rats with suboptimal CMT-8 alone or suboptimal clodronate alone produced slight reductions in the tissue-destructive proteinases and no significant reductions in alveolar bone loss. However, a combination of suboptimal CMT-8 and clodronate "normalized" the pathologically elevated levels of MMPs, elastase, and alveolar bone loss, indicating synergistic inhibition of tissue breakdown in this animal model of periodontitis. CONCLUSIONS: Combination of a CMT and a bisphosphonate may be a useful treatment to optimally suppress periodontal destruction and tooth loss and in other tissue-destructive inflammatory diseases such as arthritis.

The lipophilicity, pharmacokinetics, and cellular uptake of different chemically-modified tetracyclines (CMTs).

CMTs are analogs of tetracyclines, which are chemically modified to eliminate their antimicrobial efficacy but which retain their inhibitory activity against matrix metalloproteinases. These compounds have been found to inhibit connective tissue breakdown in animal models of diseases such as periodontitis, arthritis and cancer. Because CMTs exhibit different in vivo efficacy in these various models of disease, the current study compared their pharmacokinetics and other properties as follows: Adult male Sprague-Dawley rats were administered by oral gavage a single dose of 5mg of different CMTs suspended in 1 ml 2% carboxymethyl-cellulose, and blood samples were collected from 1-48 hours after dosing. The sera were extracted, then analyzed by HPLC using a C-18 reverse-phase column. The results showed that the peak concentrations (C(max)) in rat sera 1-12 hours after oral administration of CMTs -1, -2,-3, -4,-5,-6,-7,-8 and doxycycline were 5.5, 0.7, 4.6, 6.2, 0.8, 0.7, 9.0 (note: the 3 peaks detected for CMT-7 were combined), 15.0 and 0.9 microg/ml, respectively. Their in vivo half-lives (t(1/2)) were 11, 5, 22, 11, 32, 15, 37, 38, and 17 hours, respectively. Of the anticollagenase CMTs tested, CMT-8 showed the greatest C(max) and t(1/2)values, followed by CMTs-3, -1, -4, and perhaps -7; CMTs-2, -5, and -6 exhibited much lower levels in serum. The relative lipophilicities of the 8 CMTs and doxycycline were tested by examining their extractability in octanol. The results showed that CMT-2, -5, and -6 had the lowest partition coefficients using this organic solvent, while CMT-3 was the most lipophilic. The lipophilicity of the different CMTs was also positively correlated (r(2)=0.767, P<0.05) to peak serum concentrations (C(max)), but not to their serum half-lives (r(2)=0.25,P=0.49). This property of the different CMTs was also found to be positively correlated to their ability to enter into human whole blood cells in vitro (r2=0.95, P<0.001). Since CMT-8, as well as CMTs-3 and -1, consistently exhibited the greatest in vivo efficacy in animal models of tissue breakdown, this may reflect, at least in part, their favorable pharmacokinetics and tissue uptake.

Biodistribution of radiolabeled [(3)H] CMT-3 in rats.

CMT-3 is a NON-ANTIMICROBIAL tetracycline (TC), chemically modified to enhance its collagenase-inhibitory property. This property is therapeutically useful in treating diseases such as periodontitis, cancer and arthritis. CMT-3 was labeled with tritium [(3)H] at Carbon 7. Four adult male Sprague-Dawley rats (350--400 g body weight) were gavaged once with a mixture of cold CMT-3 and [(3)H] CMT-3 (750 microCi). An additional four rats were gavaged for 2 days with cold CMT-3(15 mg/Kg/day) and on the third day the rats were gavaged with a mixture of cold and [(2)H] CMT-3 (750 microCi); and all 8 rats were placed in the metabolic cages. Blood samples were collected from the tail at multiple intervals from 1--14 hr after [(3)H] CMT-3 administration. At 14 hr, the rats were anesthetized, euthanized and various tissues including visceral organs were removed and weighed. The contents of GI tracts were emptied and added to the fecal pellets and weighed. The urine samples were collected and volume measured. Each tissue or organ was minced finely with scissors and 100 mg of tissue was digested in 1 ml of Tissue-solv (Packard Lab), for 4 hrs at 37 degrees C and each sample was diluted up to 10 ml of distilled water. A 100 microl aliquot was taken and diluted with an equal volume of glacial acetic acid, 10 ml of Atom-lite was added and counted for radioactivity in a liquid scintillation spectrometer. This biodistribution study revealed that over 14 hrs, 54% and 3% of [(3)H] CMT-3 were excreted in the feces and urine, respectively. The serum [(3)H] CMT-3 count reached its maximum value at about 12 hours. The tissues retained the CMTs as follow: muscle (23%); skin (2.41%); bone (1.72%); and the brain retained 0.21% of the label. The radioactive CMT-3 in the visceral organs is as follows: GI tract - its contents (8.9%); heart (0.41%), testis (0.41%); lungs >(0.16%); spleen (0.08%); liver (0.03%); kidneys > (0.02%).

CMT-3, a non-antimicrobial tetracycline (TC), inhibits MT1-MMP activity: relevance to cancer.

Tetracyclines (TCs) and their non-antimicrobial analogs (CMTs) have therapeutic potential to inhibit tissue destructive disease processes, such as cancer invasion and metastasis, by inhibiting certain matrix metalloproteinases. Enhanced matrix metalloproteinase-2 (MMP-2; gelatinase A) activity has been correlated to cancer invasiveness, and membrane type MMP (MT1-MMP) expressed by tumor cells is involved in localizing and activating pro-MMP-2, a pathway believed to mediate cancer induced tissue breakdown. CMT-3 (6-demethyl, 6-deoxy, 4-dedimethylamino TC) has been shown to experimentally suppress prostate cancer, colon adenocarcinoma and melanoma invasiveness in cell culture and to inhibit tumor growth and metastasis in vivo and was used in the current in vitro study. Confluent MT1-MMP transfected COS-1 cells were harvested, washed thoroughly, subjected to N(2) cavitation and cell membrane enriched fractions were isolated by sequential centrifugations. This MT1-MMP preparation exhibited (i) pro-MMP-2 activating activity as shown by molecular weight shift of this gelatinase from 72 kDa to 62 kDa using gelatin zymography, and (ii) the ability to degrade both [(3)H-methyl] gelatin and casein at 37 degrees C. Adding CMT-3 at final concentrations of 5--20microM inhibited MT1-MMP gelatinolytic and caseinolytic activity, blocked MT1-MMP activation of pro-MMP-2, and decreased invasiveness (using the Matrigel system) of HT-1080 fibrosarcoma cells. The inhibition of MT1-MMP by CMT-3 may partially explain the inhibition of cancer cell -mediated tissue breakdown and invasiveness by this non-antimicrobial tetracycline analog.

Inhibition of tumor cell invasiveness by chemically modified tetracyclines.

COLO 205 is a cell line derived from a human colon carcinoma with high degradative activity towards extracellular matrix (ECM). It has been shown that COLO 205 cells produce matrix metalloproteinases (MMPs). MMPs are a family of enzymes known to degrade components of the ECM and have been implicated in tumor invasion. In the present study, we have analyzed the multiple effects of chemically modified tetracyclines (CMTs) on the expression and activity of MMPs secreted by COLO 205 cells in vitro with the aim of evaluating these compounds for potential use in management of invasive tumors. Because COLO 205 cells can degrade an interstitial ECM in serum-free medium in vitro, we have been able to compare the effects of the tetracyclines on this measure of invasive activity with their effects on proteinase expression and activity. We demonstrate here that one of the chemically modified tetracyclines, 6-deoxy-6-demethyl-4-de(dimethylamino)tetracycline (CMT-3) can effectively inhibit ECM degradation mediated by COLO 205 cells or their conditioned medium. Gelatin zymography and immunoblots show that CMT-3 has the ability to inhibit release of MMP-2 into conditioned medium as well as to inhibit MMP-2 gelatinolytic activity, which correlates with the results from ECM degradation assays. On the basis of our findings with COLO 205 cells we have expanded our evaluation of the tetracyclines to include effects on a genetically engineered line of MDA-MB-231 breast tumor cells overexpressing MMP-9 at levels over tenfold those of the parent cell line, and on three human prostate tumor cell lines, LNCaP, DU-145, and PC-3. We show here that CMT-3 displays multiple modes of action: inhibiting MMP activity, reducing levels of MMP expression, and exhibiting selective cytotoxicity towards some of the tumor cell lines.

A combination of subtherapeutic doses of chemically modified doxycycline (CMT-8) and a bisphosphonate (clodronate) inhibits bone loss in the ovariectomized rat: a dynamic histomorphometric and gene expression study.

Recent studies have demonstrated that tetracyclines can reduce bone loss in the ovariectomized (OVX) rat model of osteoporosis. In the current study, a non-antimicrobial, chemically modified doxycycline (CMT-8), alone or in combination with a bisphosphonate (Clodronate), was evaluated in this model. Forty-two, 6month old, female rats were randomly assigned to the following groups, (6/ group): a) sham/vehicle, b) OVX/vehicle; c) OVX/1 mg/day CMT-8; d) OVX/2 mg/day CMT-8, e) OVX/1 mg/week Clodronate; and f) OVX/1 mg/day CMT-8 + 1 mg/week Clodronate, CMT-8 was administered by oral gavage, Clodronate injected S/C. Following sham surgery or OVX, the rats were treated for 90 days with CMT-8 or vehicle alone, injected at three different times with fluorochrome labels, the rats were sacrificed, and the tibiae excised for analysis by dynamic bone histomorphometry. Femurs were aseptically removed and analyzed for collagen, collagenase and osteopontin mRNAs by Northern and dot blot analysis. As expected, OVX decreased trabecular bone volume (BV/TV by 73.8% vs. sham p<.01), and also reduced trabecular thickness, numbers, and increased spacing. Bone loss in the OVX animals was partially prevented with either 2 mg/day CMT-8 or 1 mg/wk Clodronate (p<.01), while the 1 mg/day CMT-8 had no effect. Interestingly, the efficacy of the combination therapy of CMT-8 and Clodronate was significantly better than either treatment by itself, maintaining bone mass and structural indices at levels identical to sham values. OVX rats mRNA for collagen, collagenase and osteopontin were elevated indicating high-turnover bone loss. Only COMBO therapy significantly reduced the collagenase and osteopontin mRNA. In summary, CMT-8 mono-therapy (2 mg) alone partially inhibited bone loss in this animal model of osteoporosis. However, 1 mg/day (CMT-8) monotherapy had no effect on bone loss or bone mRNA levels and when combined with Clodronate, interacted to increase efficacy. Thus, a combination of a suboptimal dose of CMT-8 and a bisphosphonate appears to increase the amount of bone by suppressing resorption in a model of osteoporosis.

Excessive matrix metalloproteinase activity in diabetes: inhibition by tetracycline analogues with zinc reactivity.

Diabetes mellitus in rats is characterized by excessive activity of several matrix metalloproteinases (MMPs), notably collagenase(s) and gelatinase(s), in skin, gingiva, and other tissues. A number of tetracyclines (TCs), both antimicrobial compounds as well as chemically modified non-antimicrobial TC analogues (CMTs) are known to possess potent inhibitory activity against these enzymes. Three conventional antimicrobial TCs and six CMTs were used in this study. In vitro, doxycycline was shown to possess higher inhibitory capacity (i.e. lower IC(max)) against diabetic rat skin collagenase than either minocycline or tetracycline HCl. Addition of excess zinc partially reversed the proteinase inhibition by TCs. In vivo, using rats made diabetic with streptozotocin (STZ), oral administration of various TCs led to decreased weight loss and substantial reductions in the activity of both skin collagenase and skin gelatinase (primarily MMP-9, 92 kDa) without affecting blood glucose. Using an in vitro spectrophotometric technique, the Zn(++) reactivity of several CMTs was assessed and found to be positively related to the potency of these compounds as MMP inhibitors. One particular CMT (CMT-5, pyrazole analogue), which is neither antimicrobial nor capable of binding metal cations, did not inhibit the MMPs. TCs have potential utility in management of diabetic complications mediated by excessive activity of MMPs.

Adjunctive treatment with subantimicrobial doses of doxycycline: effects on gingival fluid collagenase activity and attachment loss in adult periodontitis.

OBJECTIVES: The therapeutic effects of doxycycline and other tetracyclines in the treatment of periodontitis involve, at least in part, mechanisms that are unrelated to their antimicrobial activity. Previous clinical studies have shown that doxycycline administered orally, at doses below those needed for antimicrobial efficacy, to human subjects with adult periodontitis resulted in significantly reduced collagenase activity in gingival crevicular fluid (GCF) and in extracts of inflamed gingival tissues. The purpose of the present study was to identify clinically effective dosing regimens using subantimicrobial dose doxycycline (SDD) as an adjunctive therapy in patients with adult periodontitis. MATERIAL AND METHODS: A total of 75 adult men and women qualified for enrollment into the three-part, placebo-controlled, double-blind, parallel-group study. Patients were stratified based on repeatedly exhibiting pathologic levels of periodontal attachment (ALv) and GCF collagenase activity at several appointments prior to baseline. Patients were administered a scaling and prophylaxis, then 1 of 5 treatment schedules for 12 weeks (part I), followed by a 12-week period of no drug therapy (part II), a second scaling and prophylaxis, and 12 additional weeks of treatment (part III). Primary determinants of efficacy included reductions in GCF collagenase activity and changes in relative ALv. RESULTS: 66 patients completed the 1st 12 weeks (part I) of the 3-part, 36-week study; 51 patients completed the entire 36-week study. From baseline to week 12 (part I), treatment with specially formulated SDD capsules (20 mg) 2x daily (1 x every 12 h) for up to 12 weeks was shown to significantly reduce GCF collagenase activity and to improve ALv, effects not seen in patients treated with placebo. Continuous drug therapy over the 12-week treatment period was needed to maintain and maximize the reduction in GCF collagenase and the improvement in ALv. Improvements in periodontal disease parameters occurred without the emergence of doxycycline-resistant micro-organisms. In patients administered an "on-off-on" regimen of SDD over 36 weeks (parts I-III), essentially no attachment loss occurred in patients receiving the highest of these SDD regimens (20 mg 2x daily during part I and 20 mg 1 x daily in part III), whereas patients administered placebo capsules experienced a mean attachment loss of approximately 0.8 mm at the 24- and 36-week time periods. CONCLUSIONS: Doxycycline administered at subantimicrobial doses led to improvements in disease parameters, with no apparent side effects, and appears to have significant potential as an oral adjunctive therapy in the long-term management of adult periodontitis.

Effects of ovariectomy on bone morphology in maxillae of mature rats.

Postmenopausal oestrogen deficiency results in bone loss (osteoporosis) in humans and experimental animals. The loss of trabecular bone in the ovariectomized (OVX) rat provides a useful experimental model of post-menopausal osteoporosis. At 5 months after ovariectomy of 3-month-old female rats, the mid and distal femurs and maxillae were dissected and processed for quantitative backscattered electron microscopic examinations. Histomorphometric analysis of femurs in OVX rats showed significant loss in metaphyseal trabecular bone areas compared with sham-operated controls; no significant bone loss was observed in the cortical bone areas of mid-diaphyses in OVX rats. Net bone areas in the maxillae of OVX rats was similar to that of sham-operated controls. Bone structure of maxillae in OVX rats was also similar to that in controls. Our results suggest that, in this animal model of osteoporosis, prominent bone loss occurs mainly in the bone areas formed by endochondral ossification such as distal femurs, but those areas formed by intramembranous ossification such as mid-femurs and maxillae sustained less effects by OVX.

Scientific basis of a matrix metalloproteinase-8 specific chair-side test for monitoring periodontal and peri-implant health and disease.

Matrix metalloproteinases (MMPs), especially collagenase-2 (MMP-8), are key mediators of irreversible tissue destruction associated with periodontitis and peri-implantitis. MMP-8 is known to exist in elevated amounts and in active form in the gingival crevicular fluid (GCF) and peri-implant sulcular fluid (PISF) from progressing periodontitis and peri-implantitis lesions and sites, respectively. (Sorsa et al. Ann. N.Y. Acad. Sci. 737: 112-131 [1994]; Teronen et al. J. Dent. Res. 76: 1529-1537 [1997]). We have developed monoclonal antibodies to MMP-8 (Hanemaaijer et al. J. Biol. Chem. 272: 31504-31509 [1997]) that can be used in a chair-side dipstick test to monitor the course and treatment of periodontitis and peri-implantitis. Monoclonal and polyclonal antibody tests for MMP-8 coincided with the classical functional collagenase activity test from GCF and PISF (Sorsa et al. J. Periodont. Res. 22: 386-393 [1988]) in periodontal and peri-implant health and disease. In future a chair-side functional and/or immunological MMP-test can be useful to diagnose and monitor periodontal and peri-implant disease and health.