Molecular size distribution analysis of human gingival proteoglycans and glycosaminoglycans in specific periodontal diseases

Matrix Metalloproteinases in the Periodontium-Vital in Tissue Turnover and Unfortunate in Periodontitis

The extracellular matrix (ECM) is a complex non-cellular three-dimensional macromolecular network present within all tissues and organs, forming the foundation on which cells sit, and composed of proteins (such as collagen), glycosaminoglycans, proteoglycans, minerals, and water. The ECM provides a fundamental framework for the cellular constituents of tissue and biochemical support to surrounding cells. The ECM is a highly dynamic structure that is constantly being remodeled. Matrix metalloproteinases (MMPs) are among the most important proteolytic enzymes of the ECM and are capable of degrading all ECM molecules. MMPs play a relevant role in physiological as well as pathological processes; MMPs participate in embryogenesis, morphogenesis, wound healing, and tissue remodeling, and therefore, their impaired activity may result in several problems. MMP activity is also associated with chronic inflammation, tissue breakdown, fibrosis, and cancer invasion and metastasis. The periodontium is a unique anatomical site, composed of a variety of connective tissues, created by the ECM. During periodontitis, a chronic inflammation affecting the periodontium, increased presence and activity of MMPs is observed, resulting in irreversible losses of periodontal tissues. MMP expression and activity may be controlled in various ways, one of which is the inhibition of their activity by an endogenous group of tissue inhibitors of metalloproteinases (TIMPs), as well as reversion-inducing cysteine-rich protein with Kazal motifs (RECK).

The molecular weight of hyaluronic acid influences metabolic activity and osteogenic differentiation of periodontal ligament cells

OBJECTIVE

While HA is present naturally in periodontal tissues, its molecular weight can vary widely in vivo. The objective of this study was to directly compare the biological reactions of periodontal ligament cells to four distinct molecular weights of hyaluronic acid (HA).

MATERIALS AND METHODS

Immortalized human periodontal ligament cells (PDL-hTERT) were cultured for 21 days in culture medium alone (control) or enriched with osteogenic supplements (OS group). Other 4 experimental groups were cultured in OS medium with the addition of HA with different molecular weights (HMW, MMW, LMW, and ULMW). The cell morphology was examined daily. WST1 assays were performed to evaluate metabolic activity. Von Kossa staining and calcium deposition assay were used to analyze osteogenic differentiation and mineralization.

RESULTS

Cell morphology remained unaltered in all groups. Cells stimulated with OS alone or with the addition of hyaluronan showed all the typical microscopic appearance of osteogenic differentiation. Metabolic activity increased in all groups over time. Hyaluronan stimulated greater metabolic activity than the control group, with LMW HA and MMW HA showing the most significant increase. All groups showed mineral deposits and calcium deposition after 21 days of stimulation.

CONCLUSION

Our results suggest that hyaluronan can promote metabolic activity and mineralization of PDL-hTERT cells, with LMW HA being the most effective.

CLINICAL RELEVANCE

These results shed light on how the various molecular weight fractions of HA promote tissue regeneration and repair, as well as help to identify an optimal molecular weight range for this application in periodontal tissues.

A thermosensitive gel with an active hyaluronic acid ingredient that contains an octenidine preservation system as an adjunct to scaling and root planning: a randomized prospective clinical study

OBJECTIVES

To evaluate the adjunctive effect of a thermosensitive gel formulation that contains 0.8% oligo hyaluronic acid (HA) combined with a preservation system of octenidine HCl 0.625% and phenoxyethanol to scaling and root planing (SRP) as compared with SRP alone in the treatment of residual pockets of patients with stage 3 periodontitis.

MATERIALS AND METHODS

Thirty-four patients (21 males and 13 females) aged 29-78 years (51.3 ± 13.1) with stage 3 periodontitis were recruited to participate in the present split-mouth study. None of the patients has been previously treated for periodontitis. Plaque index (PI), probing depth (PD), clinical attachment level (CAL), and bleeding on probing (BOP) were evaluated at baseline and at 3 and 6 months post treatment. Full-mouth SRP was performed in all residual pockets ≥ 5 mm. Treatment was performed by means of ultrasonic and hand instruments and lasted 45-60 min. The gel was applied subgingivally in the test sites immediately after SRP (baseline) and 1 month later. The paired t-test for two means was applied to test the statistical significance of the change from baseline within each arm and determine the difference between groups. The level of significance was set at 0.05 for all tests.

RESULTS

Mean PD reductions between baseline and 3 and 6 months were 1.98 mm and 2.79 mm for the test and 1.22 mm and 1.50 mm for the control group, respectively. Comparisons between the test and control groups revealed that SRP + gel yielded statistically significantly higher PD reductions compared to SRP alone (p < 0.0001). Compared to baseline, CAL and BOP values improved statistically significantly in both groups, although the test group presented statistically significantly higher CAL gains and BOP reductions than the control group (P < 0.0001).

CONCLUSION

In residual pockets of stage 3 periodontitis patients, the local application of a thermosensitive gel with an active HA ingredient and a preservation system of octenidine HCl 0.625% in conjunction with SRP may additionally improve the clinical outcomes obtained with SRP alone.

CLINICAL RELEVANCE

A novel HA and octenidine containing thermosensitive gel effectively improved the clinical parameters in stage 3 periodontitis patients over a 6-month period.

Modification of gingival proteoglycans by reactive oxygen species: potential mechanism of proteoglycan degradation during periodontal diseases

Reactive oxygen species (ROS) overproduction and oxidative stress are increasingly being implicated in the extracellular matrix (ECM) degradation associated with chronic inflammatory conditions, such as periodontal diseases. The present study investigated the effects of ROS exposure on the proteoglycans of gingival tissues, utilizing an in vitro model system comprised of supra-physiological oxidant concentrations, to ascertain whether gingival proteoglycan modification and degradation by ROS contributed to the underlying mechanisms of ECM destruction during active gingivitis. Proteoglycans were purified from ovine gingival tissues and exposed to increasing H₂O₂ concentrations or a hydroxyl radical (·OH) flux for 1 h or 24 h, and ROS effects on proteoglycan core proteins and sulfated glycosaminoglycan (GAG) chains were assessed. ROS were capable of degrading gingival proteoglycans, with ·OH species inducing greater degradative effects than H₂O₂ alone. Degradative effects were particularly manifested as amino acid modification, core protein cleavage, and GAG chain depolymerization. Proteoglycan core proteins were more susceptible to degradation than GAG chains with H₂O₂ alone, although core proteins and GAG chains were both extensively degraded by ·OH species. Proteoglycan exposure to ·OH species for 24 h induced significant core protein amino acid modification, with decreases in glutamate, proline, isoleucine, and leucine; and concomitant increases in serine, glycine, and alanine residues. As clinical reports have previously highlighted proteoglycan core protein degradation during chronic gingivitis, whereas their sulfated GAG chains remain relatively intact, these findings potentially provide further evidence to implicate ROS in the pathogenesis of active gingivitis, complementing the enzymic mechanisms of periodontal tissue destruction already established.

Development and Evaluation of Thermosensitive Hydrogels with Binary Mixture of Scutellariae baicalensis radix Extract and Chitosan for Periodontal Diseases Treatment

Scutellaria baicalensis root displays anti-inflammatory and antibacterial properties due to the presence of flavonoids, particularly baicalin, baicalein, and wogonin. Our work aimed at developing thermosensitive hydrogels containing a binary mixture of S. baicalensis radix lyophilized extract and chitosan as a novel approach for periodontal diseases treatment. Two types of chitosan were employed in preliminary studies on binary mixtures with S. baicalensis radix lyophilized extract standardized for baicalin, baicalein, and wogonin. Thermosensitive hydrogels were prepared of poloxamer 407, alginate sodium, and cellulose derivatives and evaluated in terms of rheological and mucoadhesive behavior. The presence of chitosan altered the release profile of active compounds but did not affect their in vitro permeation behavior in PAMPA assay. The synergistic effects of S. baicalensis radix lyophilized extract and chitosan toward ferrous ion-chelating activity, inhibition of hyaluronidase, and pathogen growth were observed. The thermosensitive gelling system showed shear-thinning properties, gelation temperature between 25 and 27 °C, and favorable mucoadhesiveness in contact with porcine buccal mucosa, which was enhanced in the presence of binary mixture of S. baicalensis radix extract and chitosan. The release tests showed that baicalin and baicalein were liberated in a prolonged manner with a fast onset from hydrogel formulations.

Levels of low-molecular-weight hyaluronan in periodontitis-treated patients and its immunostimulatory effects on CD4+ T lymphocytes

OBJECTIVES

During periodontitis, chronic inflammation triggers soft tissue breakdown, and hyaluronan is degraded into fragments of low molecular weight (LMW-HA). This investigation aimed to elucidate whether LMW-HA fragments with immunogenic potential on T lymphocytes remain in periodontal tissues after periodontal treatment.

MATERIALS AND METHODS

GCF samples were obtained from 15 periodontitis-affected patients and the LMW-HA, RANKL, and OPG levels were analyzed before and after 6 months of periodontal treatment by ELISA. Eight healthy individuals were analyzed as controls. Besides, human T lymphocytes were purified, exposed to infected dendritic cells, and pulsed with LMW-HA. Non-treated T lymphocytes were used as control. The expression levels of the transcription factors and cytokines that determine the Th1, Th17, and Th22 lymphocyte differentiation and function were analyzed by RT-qPCR. Similarly, the expression levels of RANKL and CD44 were analyzed.

RESULTS

In the GCF samples of periodontitis-affected patients, higher levels of LMW-HA were detected when compared with those of healthy individuals (52.1 ± 15.4 vs. 21.4 ± 12.2, p < 0.001), and these increased levels did not decrease after periodontal therapy (52.1 ± 15.4 vs. 45.7 ± 15.9, p = 0.158). Similarly, the RANKL levels and RANKL/OPG ratios did not change after periodontal therapy. Furthermore, in human T lymphocytes, LMW-HA induced higher expression levels of the Th1, Th17, and Th22-related transcription factors and cytokines, as well as CD44 and RANKL, as compared with non-treated cells.

CONCLUSIONS

In some patients, increased levels of LMW-HA persist in periodontal tissues after conventional periodontal therapy, and these remaining LMW-HA fragments with immunostimulatory potential could induce the polarization of a pathologic Th1/Th17/Th22-pattern of immune response on T lymphocytes.

CLINICAL RELEVANCE

The persistence of increased levels of LMW-HA in periodontal tissues after periodontal therapy could favor the recurrence of the disease and further breakdown of periodontal supporting tissues.

Commercial Local Pharmacotherapeutics and Adjunctive Agents for Nonsurgical Treatment of Periodontitis: A Contemporary Review of Clinical Efficacies and Challenges

Periodontal infections tend to be site-specific, mostly confined to the periodontal pocket. With the surge of antibiotic-resistant bacteria, the trend is shifting towards other therapeutic modalities, especially locally delivered approaches that include other pharmacotherapeutic drugs and medical devices. This narrative review aimed to provide insights into the clinical efficacy of local drug delivery and adjunctive agents used in nonsurgical management of periodontitis. Electronic (PubMed/MEDLINE, CENTRAL, and EMBASE) and bibliographic searches of past systematic reviews were carried out to identify previous publications on the topic. Only relevant literature and randomized controlled trials published in English were selected. In addition, a literature review was developed based on the selected articles. Experimental drugs or agents were excluded. This review highlights the clinically proven and commercially available therapeutic agents related to the management of periodontal disease with comparisons of their clinical efficacies and challenges. A vast array of commercial local pharmacotherapeutic agents had been clinically tested, but the methodologies and clinical results varied within and between each agent used, causing difficulty in drawing conclusions and providing support to the superiority of one agent over another. Considering the benefit-cost ratio with the modest clinical results, the long-term usefulness of these agents remains debatable.

Immunostimulatory activity of low-molecular-weight hyaluronan on dendritic cells stimulated with Aggregatibacter actinomycetemcomitans or Porphyromonas gingivalis

OBJECTIVES

Periodontitis is a chronic inflammatory disease characterized by tooth-supporting tissue destruction, which is elicited by the host's immune response triggered against periodonto-pathogen bacteria. During periodontal tissue destruction, extracellular matrix components are metabolized and fragmented. Some extracellular matrix component-derived fragments, such as low-molecular-weight hyaluronan (LMW-HA), have potent immunogenic potential, playing a role as damage-associated molecular patterns (DAMPs) during activation of immune cells. Dendritic cells (DCs) play a central role in the host's immune response displayed during periodontitis; thus, this study aimed to analyze whether LMW-HA has an immunostimulatory activity on DCs when stimulated with periodonto-pathogen bacteria.

MATERIALS AND METHODS

LMW-HA-treated and non-treated DCs were stimulated with Aggregatibacter actinomycetemcomitans or Porphyromonas gingivalis and the mRNA expression for cytokines tumor necrosis factor-α (TNF-alpha), interleukin-1β (IL-1B), interleukin-6 (IL-6), and interleukin-23 (IL-23A) was quantified by RT-qPCR. In addition, transcription factors interferon regulatory factor 4 (IRF4), interferon regulatory factor 8 (IRF8), neurogenic locus notch homolog protein 2 (NOTCH2), and basic leucine zipper ATF-like transcription factor 3 (BATF3), involved in DC activation, were analyzed.

RESULTS

Higher expression levels of TNF-alpha, IL-1B, IL-6, and IL-23A were detected in LMW-HA-treated DCs after bacterial infection, as compared with non-treated DCs. When LMW-HA-treated DCs were infected with A. actinomycetemcomitans, higher levels of IRF4, NOTCH2, and BATF3 were detected compared with non-treated cells; whereas against P. gingivalis infection, increased levels of IRF4 and NOTCH2 were detected.

CONCLUSION

LMW-HA plays an immunostimulatory role on the immune response triggered by DCs during infection with A. actinomycetemcomitans or P. gingivalis.

CLINICAL RELEVANCE

Detection of extracellular matrix component-derived fragments produced during periodontal tissue destruction, such as LMW-HA, could explain at least partly unsuccessful periodontal treatment and the chronicity of the disease.

In vitro effects of hyaluronic acid on human periodontal ligament cells

Background

Hyaluronic acid (HA) has been reported to have a positive effect on periodontal wound healing following nonsurgical and surgical therapy. However, to date, a few basic in vitro studies have been reported to investigating the potential of HA on human periodontal ligament (PDL) cell regeneration. Therefore, the aim of this study was to investigate the effect of HA on PDL cell compatibility, proliferation, and differentiation in vitro.

Methods

Either non-cross-linked (HA_ncl) or cross-linked (HA_cl) HA was investigated. Human PDL cells were seeded in 7 conditions as follows (1) Control tissue culture plastic (TCP) (2) dilution of HA_ncl (1:100), (3) dilution of HA_ncl (1:10), 4) HA_ncl directly coated onto TCP, (5) dilution of HA_cl (1:100), 6) dilution of HA_cl (1:10) and (7) HA_cl directly coated onto TCP. Samples were then investigated for cell viability using a live/dead assay, an inflammatory reaction using real-time PCR and ELISA for MMP2, IL-1 and cell proliferation via an MTS assay. Furthermore, the osteogenic potential of PDL cells was assessed by alkaline phosphatase(ALP) activity, collagen1(COL1) and osteocalcin(OCN) immunostaining, alizarin red staining, and real-time PCR for genes encoding Runx2, COL1, ALP, and OCN.

Results

Both HA_ncl and HA_cl showed high PDL cell viability (greater than 90%) irrespective of the culturing conditions. Furthermore, no significant difference in both mRNA and protein levels of proinflammatory cytokines, including MMP2 and IL-1 expression was observed. Both diluted HA_ncl and HA_cl significantly increased cell numbers compared to the controlled TCP samples at 3 and 5 days. HA_ncl and HA_cl in standard cell growth media significantly decreased ALP staining, COL1 immunostaining and down-regulated early osteogenic differentiation, including Runx2, COL1, and OCN mRNA levels when compared to control samples. When osteogenic differentiation medium (ODM) was added, interestingly, the expression of early osteogenic markers increased by demonstrating higher levels of COL1 and ALP expression; especially in HA 1:10 diluted condition. Late stage osteogenic markers remained inhibited.

Conclusions

Both non-cross-linked and cross-linked HA maintained high PDL cell viability, increased proliferation, and early osteogenic differentiation. However, HA was consistently associated with a significant decrease in late osteogenic differentiation of primary human PDL cells. Future in vitro and animal research is necessary to further characterize the effect of HA on periodontal regeneration.

Hyaluronic acid: Perspectives in dentistry. A systematic review

To date, topical therapies guarantee a better delivery of high concentrations of pharmacologic agents to the soft periodontal tissue, gingiva, and periodontal ligament as well as to the hard tissue such as alveolar bone and cementum. Topical hyaluronic acid (HA) has recently been recognized as an adjuvant treatment for chronic inflammatory disease in addition to its use to improve healing after dental procedures. The aim of our work was to systematically review the published literature about potential effects of HA as an adjuvant treatment for chronic inflammatory disease, in addition to its use to improve healing after common dental procedures. Relevant published studies were found in PubMed, Google Scholar, and Ovid using a combined keyword search or medical subject headings. At the end of our study selection process, 25 relevant publications were included, three of them regarding gingivitis, 13 of them relating to chronic periodontitis, seven of them relating to dental surgery, including implant and sinus lift procedures, and the remaining three articles describing oral ulcers. Not only does topical administration of HA play a pivotal key role in the postoperative care of patients undergoing dental procedures, but positive results were also generally observed in all patients with chronic inflammatory gingival and periodontal disease and in patients with oral ulcers.

Targeting gallbladder cancer: oncolytic virotherapy with myxoma virus is enhanced by rapamycin in vitro and further improved by hyaluronan in vivo

Background

Gallbladder carcinoma (GBC) is highly lethal, and effective treatment will require synergistic anti-tumor management. The study is aimed at investigating the oncolytic value of myxoma virus (MYXV) infection against GBC and optimizing MYXV oncolytic efficiency.

Methods

We examined the permissiveness of GBC cell lines to MYXV infection and compared the effects of MYXV on cell viability among GBC and control permissive glioma cells in vitro and in vivo after MYXV + rapamycin (Rap) treatment, which is known to enhance cell permissiveness to MYXV by upregulating p-Akt levels. We also assessed MYXV + hyaluronan (HA) therapy efficiency by examinating Akt activation status, MMP-9 expression, cell viability, and collagen distribution. We further compared hydraulic conductivity, tumor area, and survival of tumor-bearing mice between the MYXV + Rap and MYXV + HA therapeutic regimens.

Results

MYXV + Rap treatment could considerably increase the oncolytic ability of MYXV against GBC cell lines in vitro but not against GBC xenografts in vivo. We found higher levels of collagen IV in GBC tumors than in glioma tumors. Diffusion analysis demonstrated that collagen IV could physically hinder MYXV intratumoral distribution. HA–CD44 interplay was found to activate the Akt signaling pathway, which increases oncolytic rates. HA was also found to enhance the MMP-9 secretion, which contributes to collagen IV degradation.

Conclusions

Unlike MYXV + Rap, MYXV + HA therapy significantly enhanced the anti-tumor effects of MYXV in vivo and prolonged survival of GBC tumor-bearing mice. HA may optimize the oncolytic effects of MYXV on GBC via the HA–CD44 interaction which can promote viral infection and diffusion.

Regulation of hyaluronan synthase-2 expression in human intestinal mesenchymal cells: mechanisms of interleukin-1beta-mediated induction

Elevated levels of hyaluronan are associated with numerous inflammatory diseases including inflammatory bowel disease. The purpose of this study was to determine whether a cause and effect relationship might exist among proinflammatory cytokines, IL-1beta, TNF-alpha, IFN-gamma, or transforming growth factor-beta (TGF-beta) and hyaluronan expression in human JDMC and, if so, to identify possible mechanisms involved in the induction of hyaluronan expression. TGF-beta, TNF-alpha, and IFN-gamma had little or no effect on hyaluronan production by these cells. Treatment with IL-1beta induced an approximate 30-fold increase in the levels of hyaluronan in the medium of human jejunum-derived mesenchymal cells. Ribonuclease protection analysis revealed that steady-state transcript levels for hyaluronan synthase (HAS)2 were present at very low levels in untreated cells but increased as much as 18-fold in the presence of IL-1beta. HAS3 transcript levels were also increased slightly by exposure of these cells to IL-1beta. Expression of HAS1 transcripts was not detected under any condition in these cells. IL-1beta induction of hyaluronan expression was inhibited in cells transfected with short interfering RNA corresponding to HAS2 transcripts. Inhibitors of the p38 and ERK1/2 mitogen-activated pathways but not JNK/SAPK blocked the IL-1beta-mediated induction of hyaluronan expression and the increase in HAS2 transcript expression. These results suggest that IL-1beta induction of HAS2 expression involves multiple signaling pathways that act in concert, thus leading to an increase in expression of hyaluronan by jejunum-derived mesenchymal cells.

Regulation of hyaluronan synthases in mouse uterine cervix

We examined the expression pattern of hyaluronan synthase (HAS) mRNAs in the uterine cervix of pregnant mice. The expression levels of HAS-1 and -2 mRNAs peaked at delivery, whereas that of HAS-3 mRNA peaked on the 15th day of pregnancy. The regulation of HAS mRNA expression was examined in pregnant mouse uterine cervical fibroblasts. The expression of HAS-1, -2, and -3 mRNAs was significantly augmented by interleukin-1beta (IL-1beta). Progesterone significantly interfered with expression of HAS-1 and -2 mRNAs, but significantly increased the expression of HAS-3 mRNA. Low-molecular-weight hyaluronan significantly enhanced only the expression of HAS-1 mRNA. These results indicate that HAS in the uterine cervix is regulated in a complex manner by IL-1beta, progesterone, and low-molecular-weight hyaluronan, of which changes in the cervical tissue and serum closely participate in uterine cervical ripening and/or inflammation.

Total Proteoglycan and Chondroitin-4- Sulfate Levels in Gingiva of Patients With Various Types of Periodontitis

BACKGROUND

The aim of the present study was to investigate the total proteoglycan (PG) and chondroitin-4-sulfate (C4S) levels in gingival tissue samples obtained from patients with aggressive periodontitis (AgP) and chronic periodontitis (CP) before therapy (baseline) and 1 month after completion of non-surgical periodontal therapy.

METHODS

Gingival tissue samples were obtained from 10 AgP and 10 CP patients before initiation of treatment (baseline) and 1 month after non-surgical periodontal treatment. The control group comprised 10 systemically and periodontally healthy subjects. Total PG and C4S levels were determined by biochemical techniques. PG levels were analyzed using a modified Bitter and Muir method. C4S assay was carried out using chondroitin sulphate lyase AC and chondroitin-6 sulphate sulphohydrolase enzymes. The results were tested statistically using parametric tests.

RESULTS

The clinical periodontal parameters demonstrated significant decreases in the periodontitis groups (P<0.05) after treatment, and there was no significant difference between AgP and CP groups at baseline and after treatment (P>0.05). At baseline, total PG and C4S levels in both of the periodontitis groups were significantly lower than that of the control group (P<0.05). One month after the non-surgical periodontal treatment, total PG levels in the periodontitis groups were comparable to the control group (P>0.05), whereas C4S levels in the AgP group were significantly lower than the other study groups (P<0.05). In the CP group, total PG and C4S levels increased significantly (P = 0.001 and P = 0.006, respectively) after non-surgical periodontal treatment, but they did not increase in the AgP group (P>0.05).

CONCLUSION

The significant increases observed in total proteoglycan and chondroitin-4-sulfate levels after non-surgical periodontal treatment in the CP group but not in the AgP group may suggest that healing patterns differ between the two periodontitis types in terms of PG and C4S composition of extracellular matrix.

Endogenous Hyaluronan: A Cytokine-Like Factor Present in Rabbit Uterine Cervix during Pregnancy

The effects of endogenous hyaluronan on cervical ripening during pregnancy were examined in rabbits. Hyaluronan of approximately 620 kilodalton (kDa) was detected in the uterine cervix on the 25th and 29th days of pregnancy, while it was not detected in cervix of non-pregnant animals. In addition, low-molecular-weight (less than 191 kDa) hyaluronan was present in cervix at the 29th day of pregnancy. Hyaluronan level in the cervix was lower on the 29th day than on the 25th day of pregnancy, whereas that in serum was significantly higher on the 29th day than on the 25th day of pregnancy. To clarify the physiological functions of endogenous hyaluronan, the effects of hyaluronan (HA600-700), which had approximately equal to endogenous hyaluronan, on uterine cervical tissues and uterine cervical fibroblasts were examined. Rabbits at the 23rd day of pregnancy were administered a vaginal suppository of HA600-700 (20 mg) daily for three days. Promotion of cervical ripening was observed, as well as detachment of collagen fiber bundles, and a reduced density of collagen fiber distribution. Total collagenolytic activity was increased significantly by HA600-700 (1.0 mg/ml) treatment in cultured uterine cervical explants of pregnant rabbits as compared with the untreated group. Moreover, very similar effects of HA600-700 treatment (0.1, 1.0 mg/ml) were observed in cultured uterine cervical fibroblasts. Further, in tissue cultures, but not cell cultures, of pregnant rabbit cervix, prostaglandin E2 (PGE2) production was enhanced by HA600-700 treatment. Therefore, it appears that endogenous hyaluronan is closely concerned with cervical ripening and dilatation in uterine cervix of pregnant rabbits.

Analysis of the relationship between the severity of periodontal destruction and proteoglycan metabolism of gingiva and gingival crevicular fluid

BACKGROUND

Although it is well-described that proteoglycans (PGs) are among the major non-collagenous components of the matrix which are degraded during periodontal diseases, the relationship between PG metabolism and seventy of periodontal breakdown, the extent of degradation of PGs together with the resulting end-products, and the elimination pathways of these catabolic end-products is likely to need further clarification.

OBJECTIVE

The main aim of the present study was to analyze the possible impact of severity of periodontal destruction on PG metabolism of gingiva and gingival crevicular fluid (GCF).

MATERIAL AND METHODS

For this purpose, gingiva and GCF samples obtained from patients (n = 45) exhibiting sites (n = 57) with moderate periodontal breakdown (MP) or severe periodontal breakdown (SP) were analyzed for PG metabolism via spectrophotometric determination of uronic acid levels. Gingiva and GCF samples were obtained from the same sites in every patient to analyze the possible relationship between uronic acid content of gingival tissue and GCF.

RESULTS

No significant differences were found in uronic acid levels between sites with MP and SP (p > 0.05). The uronic acid content of GCF and gingiva showed significant overlaps between MP and SP sites and uronic acid levels did not present any constant correlation with the clinical parameters (p > 0.05). In a similar manner, uronic acid content of GCF and gingival tissue was not correlated (p > 0.05).

CONCLUSION

The lack of a significant correlation between the uronic acid content of gingival tissue and GCF may suggest that the passage of PG metabolites from gingiva to GCF is likely to be under the influence of multifactorial interactions rather than being linear. As a general measure of PG metabolism, uronic acid levels do not seem to be related with the severity of periodontal destruction and tend to act as different measures when compared to traditional clinical parameters.

Molecular size distribution analysis of human gingival glycosaminoglycans in cyclosporin- and nifedipine-induced overgrowths

Glycosaminoglycans are thought to accumulate in formative lesions like drug-induced gingival overgrowth. Recent evidences, however, suggest that the amounts of glycosaminoglycans are comparable in overgrown and healthy gingiva. Besides, alterations in the size distribution of glycosaminoglycan molecules isolated from phenytoin-induced overgrown samples have also been suggested. Therefore, we sought to determine possible differences in molecular size distribution of gingival glycosaminoglycans in other types of drug-induced overgrowths. Purified gingival glycosaminoglycans from healthy and cyclosporin- and nifedipine-induced overgrown gingival tissues were analyzed by agarose gel electrophoresis and their molecular-size distribution was evaluated by both gel filtration chromatography and polyacrylamide gel electrophoresis. Our results on the gingival glycosaminoglycan composition showed presence of chondroitin sulfate, dermatan sulfate, heparan sulfate and hyaluronic acid in all types of gingival tissues examined. In addition, hyaluronic acid was predominantly of a large size eluting near to the void volume of a Superose-6 column, while the sulfated glycosaminoglycans were mainly composed of low molecular size glycosaminoglycans. Our results show no differences in the molecular-size distribution of hyaluronic acid and sulfated glycosaminoglycans among healthy and drug-induced overgrown gingival tissues.

Expression and activity of hyaluronidase in human periodontal ligament fibroblasts

BACKGROUND

Hyaluronan is a major component of the extracellular matrix of periodontal ligament (PDL) contributing to the structural and functional integrity. Hyaluronans contribute to the buffering effect of the PDL during chewing, and they are also important in inflammation and wound healing. Hyaluronan is known to be synthesized and turned over by the resident PDL cells, although the mechanisms of hyaluronan metabolism still remain unclear. Hyaluronidase (HAase), an endoglycosidase, degrades hyaluronan into small fragments. Currently, 3 human HAases, HYAL1, HYAL2, and PH-20, have been identified and well characterized.

METHODS

This study was conducted to investigate the expression and activity of these HAases in cultured human PDL fibroblasts and to elucidate the mechanisms involved in hyaluronan metabolism under normal and inflammatory conditions. Human PDL fibroblasts derived from the periodontium of 3 premolars were cultured with or without interleukin (IL)-1beta (0.1 to 10 ng/ml) and tumor necrosis factor (TNF)-alpha (1 to 100 ng/ml) for 0 to 48 hours. The expression of HAase mRNA was assessed by reverse transcription-polymerase chain reaction (RT-PCR) and quantitative real-time PCR, and the enzymatic activity was examined using hyaluronan zymography.

RESULTS

PDL fibroblasts expressed HYAL1 and HYAL2 mRNAs, but not PH-20 mRNA. The expression of HYAL1 mRNA was enhanced by about 3.5- and 3.7-fold at maximum after 1-hour stimulation with 1 ng/ml IL-1beta and after 3-hour stimulation with 10 ng/ml TNF-alpha, respectively. The expression of HYAL2 and PH-20 mRNAs was not affected by stimulation with cytokines. HAase activity was detected in conditioned medium from PDL fibroblast cultures, and the activity was enhanced by treatment with 10 ng/ml TNF-alpha.

CONCLUSION

These results suggest that PDL fibroblasts express HAases and generate HAase activity essential for extracellular hyaluronan metabolism under physiological and inflammatory conditions.

Heparan sulfate interacting protein (HIP/L29) negatively regulates growth responses to basic fibroblast growth factor in gingival fibroblasts

Basic fibroblast growth factor (bFGF) modulates gingival growth, and its release from heparan sulfate (HS) in the extracellular matrix (ECM) governs local tissue bioavailability. We identified a heparin/HS interacting protein (HIP/L29) that recognizes specific HS sequences. We hypothesize that HIP/L29, by modulating the interactions of bFGF with HS chains on proteoglycans, could regulate bFGF bioavailability. To investigate interactions between bFGF and HIP/L29, we isolated and cultured fibroblasts from normal gingiva and overgrown gingiva from patients on cyclosporine (CSA). bFGF significantly stimulated gingival fibroblast proliferation with or without heparin. Recombinant human HIP/L29 dramatically decreased bFGF-induced proliferation, but did not alter responses to insulin-like growth factor-1 (IGF-1). Analysis of mitogen-activated protein kinase (MAPK) phosphorylation patterns showed that bFGF stimulation of p44 (Erk-1), but not p42 (Erk-2), also was inhibited by HIP/L29 in a dose-dependent manner. Together, these results support our hypothesis that HIP/L29 modulates the bioavailability and action of bFGF.

Regulation of hyaluronan synthase gene expression in human periodontal ligament cells by tumour necrosis factor-alpha, interleukin-1beta and interferon-gamma

Accumulation and fragmentation of hyaluronic (HA) accompanies the inflammatory changes in the periodontium and gingival crevicular fluid are involved in periodontitis, but the mechanism for this is unknown. Recently, three human hyaluronan-synthase (HAS1, 2, and 3) genes have been cloned and characterised as synthesising hyaluronans of different molecular weights. Both HAS1 and HAS2 synthesise high molecular-weight HA, whereas HAS3 produces lower molecular weight HA. In the present study the regulation of HAS genes by cytokines in cultured human periodontal ligament (PDL) cells was investigated using a novel real-time fluorescence polymerase chain reaction detection system. Human PDL cells derived from premolars were cultured with or without tumour necrosing factor (TNF)-alpha (1-100 ng/ml), interleukin (IL)-1beta (0.1-10 ng/ml) and interferon (IFN)-gamma (1-100 ng/ml). Expression of HAS mRNA was assessed in cultured cells treated with these cytokines for 0-24 h. The expression of HAS2 mRNA was enhanced about 4.5- and 2.2-fold at maximum after 3-h stimulation with 10 ng/ml TNF-alpha and 1 ng/ml IL-1beta, respectively, whereas IFN-gamma exerted little effect on HAS2 or HAS3 mRNA expression during the experiment. Expression of HAS3 mRNA was increased by about 14- and 10-fold after 3-h stimulation with 10 ng/ml TNF-alpha and 1 ng/ml IL-1beta, respectively. These results suggest that TNF-alpha and IL-1beta regulate HAS expression, and consequently may result in an accumulation of HA and an increase in HA of a lower molecular-weight.

Analysis of human gingival tissue and gingival crevicular fluid beta-glucuronidase activity in specific periodontal diseases

BACKGROUND

Beta-glucuronidase (betaG) is one of the enzymes involved in the destruction of non-collagenous components of the extracellular matrix. It is also considered an indicator or predictor of periodontal disease activity. The present study was conducted to determine the presence and the levels of betaG activity in gingival tissue and gingival crevicular fluid (GCF) in periodontal disease and health status. The validity of 2 expressions of data, total betaG activity versus betaG concentration, and the correlations between clinical periodontal status and betaG profile was also evaluated.

METHODS

betaG activities in gingival tissues and GCF samples from 57 individuals, divided into 3 equal groups of adult periodontitis (AP), early-onset periodontitis (EOP), and periodontally healthy subjects were spectrophotometrically examined.

RESULTS

Both patient groups had higher betaG levels in both gingiva and GCF than controls. Significant differences were observed among all groups when total GCF betaG activities were examined (P <0.05). However, the difference between AP and controls was not significant when concentration values were compared (P >0.05). The highest GCF betaG activity, with both expressions, was detected in EOP group. No absolute correlations between clinical parameters and betaG activity were observed, except for random correlations in the patient groups with mean total betaG activities. Also GCF/gingiva betaG levels and the 2 expressions did not show absolute correlations.

CONCLUSIONS

The findings of the present study confirm the relationship between betaG activity and periodontal diseases. The differences in data concerning GCF total betaG activity and betaG concentration may suggest that they are not matching measures. Data presentation seems to be an important factor in GCF/enzyme profile studies.

The importance of data presentation regarding gingival crevicular fluid myeloperoxidase and elastase-like activity in periodontal disease and health status

BACKGROUND

The enzymatic profile of gingival crevicular fluid (GCF) is being analyzed with increasing interest, but related studies lack a general consensus on most methodological points, including the appropriate mode of data presentation.

METHODS

GCF myeloperoxidase (MPO) and elastase-like activity (ELA) levels were spectrophotometrically determined on a total of 60 subjects who were divided into three equal subgroups as early-onset periodontitis (EOP), adult periodontitis (AP), and healthy. GCF enzyme levels were calculated and evaluated both as total enzyme activity and enzyme concentration. The correlations between these GCF enzymes and clinical periodontal status were also analyzed.

RESULTS

With both modes of data presentation, the results regarding MPO activity were consistent. When presented either as total MPO activity or MPO concentration, the periodontally healthy group showed significantly lower MPO activity than the two patient groups (P<0.05). However, two modes of data presentation did not match when GCF ELA was concerned. When data were reported as total ELA, the healthy group exhibited lower enzyme activity (0.02 +/- 0.001 U) than EOP (0.04 +/- 0.01 U) and AP (0.06 +/- 0.02 U) groups; but when reported as concentration, the highest ELA levels were seen in the healthy group (221 +/- 31.53 nmol/min/ml), followed by AP (98.63 +/- 23.03 nmol/min/ml) and EOP (70.49 +/- 12.02 nmol/min/ml) (P<0.05). A strong-positive and significant correlation existed between GCF MPO and ELA. Correlations with clinical parameters were mostly observed with total activities.

CONCLUSIONS

The findings of the present study confirm the relationship between GCF ELA and MPO activity and periodontal disease and also support the functional relativity between the two enzymes. Furthermore, based on these findings, it can be suggested that data presentation by use of total activity seems to be more sensitive in both the reflection of the actual enzymatic profile of GCF and also the existing clinical periodontal status. For each GCF component, the validity of different modes of data presentation should be considered.