Confirmation that neither phenotype nor hydroxylation of collagen is altered in overgrown gingiva from diphenylhydantoin-treated patients

Effect of Inflammation on the of Collagen Types, I, III, IV, and V and Type I Trimer and Fibronectin in Human Gingivae

The effect of inflammation on the distribution of collagen types I, III, IV, and V and type I trimer and fibronectin in human gingivae was studied after staining them with antibodies to these proteins, Gingival tissues were obtained after periodontal surgery and incubated with antibodies, and staining was visualized by indirect immunofluorescence using FITC- or rhodamine-conjugated second antibodies. The results showed that antibody to type I collagen stained normal gingival connective tissue uniformly and revealed the presence of thick fiber bundles, The staining was sparse at areas of inflammation and leukocytic infiltration. Anti-type-III antibody revealed a fine fibrillar netWork in the normal gingivae, especially near the epithelium; the type III was also lost at sites of inflammation. Type V collagen antibody also stained the gingival connective tissue intensely but, unlike the types I and III staining, it was retained in inflamed areas. Normal gingivae were not stained by the type I trimer antibody; however, staining occurred at inflamed sites. Both normal and inflamed tissues were stained by type IV collagen antibody. and the staining was restricted to basement membrane structures, The normal and inflamed gingivae contained a thick fiber network which bound unti-fibronectin antibody. We conclude that the various ginglvai collagen fibers are made up of collagen types I, III, and V, that the types I and III collagens are preferentially lost during inflammation, and that type I trimer appears at Inflamed sites.

Increased Accumulation of Sulfated Glycosaminoglycans in Cultures of Human Fibroblasts from Phenytoin-induced Gingival Overgrowth

Long-term ingestion of phenytoin elicits gingival overgrowth. We investigated sulfated glycosaminoglycan (GAG) metabolism by human gingival fibroblasts from normal gingivae and from phenytoin-enlarged gingivae. Incorporation, utilization, and subsequent loss of 35SO4= was measured in pulse-chase experiments. Fibroblasts from overgrown gingivae demonstrated increased accumulation of sulfated glycosaminoglycans. The increase was due to elevated synthesis and not to decreased degradation.

Medication induced gingival overgrowth

A number of idiopathic, pathological and pharmacological reactions may result in an overgrowth of the gingiva. This review concentrates on those overgrowths associated with various pharmacological agents. The pharmaco-kinetics and side effects of each drug associated with gingival overgrowth are discussed along with the clinical and histological features and treatment. By examining the possible pathogeneses for these overgrowths we propose a unifying hypothesis for the causation based around inhibition of apoptosis and decreased collagenase activity modulated by cytoplasmic calcium.

Effect of phenytoin on interleukin-1 beta production in human gingival fibroblasts challenged to tumor necrosis factor alpha in vitro

Effects and interaction of tumor necrosis factor alpha (TNF alpha) and the antiepileptic drug phenytoin (PHT) on interleukin-1 beta (IL-1 beta) production as well as on prostaglandin E2 (PGE2) formation were studied in gingival fibroblasts in vitro. TNF alpha, in contrast to PHT, dose-dependently stimulated the production of cell-associated IL-1 beta. The stimulatory effect of TNF alpha on IL-1 beta production was accompanied by enhanced PGE2 formation. When PHT and TNF alpha were added simultaneously, the drug potentiated the stimulatory effect of TNF alpha on both IL-1 beta production and PGE2 formation. The major PHT metabolite, p-HPPH, did not affect IL-1 beta production, either alone or in combination with TNF alpha. The production of IL-1 beta induced by TNF alpha and the combination of TNF alpha and PHT was further enhanced in the presence of the prostaglandin endoperoxide (PGH) synthase inhibitors, indomethacin and flurbiprofen. The PHT-mediated enhancement of TNF alpha-induced IL-1 beta production and PGE2 formation in gingival fibroblasts may be an important link in the pathogenesis of gingival overgrowth induced by PHT.

The phenytoin metabolite p-HPPH upregulates prostaglandin biosynthesis in human gingival fibroblasts challenged to interleukin-1

The effects of and interactions between the major phenytoin (PHT) metabolite 5-parahydroxyphenyl-5-phenylhydantoin (p-HPPH) and interleukin-1 (IL-1 alpha, IL-1 beta) or tumor necrosis factor alpha (TNF alpha) on prostaglandin biosynthesis in human gingival fibroblasts were studied. IL-1 alpha, IL-1 beta and TNF alpha, dose-dependently, stimulated PGE2 formation in gingival fibroblasts. The metabolite, p-HPPH (1.2-2.4 micrograms/ml), did not induce PGE2 formation itself but potentiated IL-1 alpha and IL1 beta induced PGE2 formation in the gingival fibroblasts in a manner dependent on the concentration of both IL-1 and p-HPPH. The metabolite also stimulated IL-1 induced formation of 6-Keto PGF1 alpha, the stable breakdown product of PGI2, in a dose dependent manner. IL-1 beta induces release of [3H]-arachidonic acid ([3H]-AA) from prelabelled fibroblasts, which was potentiated by p-HPPH (> or = 1.2 micrograms/ml). TNF alpha (> or = 1 ng/ml) significantly stimulated the biosynthesis of PGE2 by a process that was also potentiated by p-HPPH. Addition of exogenous, unlabelled AA (10 microM) caused an increase of PGE2 formation in the fibroblasts that was not potentiated by p-HPPH (1.6 micrograms/ml). The results indicate that treatment with p-HPPH results in upregulation of prostaglandin synthesis in gingival fibroblasts challenged to IL-1 or TNF alpha at the level of phospholipase A2.

Extracellular matrix analysis of nifedipine-induced gingival overgrowth: immunohistochemical distribution of different collagen types as well as the glycoprotein fibronectin

The purpose of this study was to demonstrate the localization of collagen types I, III, IV, V, VI and VII as well as the glycoprotein fibronectin in nifedipine-induced gingival overgrowth. The slices, after the use of indirect immunofluorescence (incubation with antibodies against these extracellular matrix components), showed a diffuse distribution with the anti-types I and III in the stroma and fluorescent staining of the basement membranes of the epithelium, blood vessels and nerves with collagen type IV antibodies. The increased number of vessels was localized near the surface of the lesion. Collagen type V - seen as a filamentous - and collagen type VI - as microfibrillar - components were also localized in the tissue, showing completely different patterns of distribution. Collagen type V appeared "crater"-like and type VI displayed a "honeycomb"-shaped structural model. The blood vessels were not stained but the area around their walls demonstrated an intense fluorescence with these antibodies. Collagen type VII showed a characteristic linear staining near to the epithelial basement membrane. In contrast to this, fibronectin localized with a varied intensity in the different areas of the tissues and presented a "cloud"-like structure. This shows differences between the matrix components in nifedipine-induced hyperplasia and confirms the heterogeneity of the matrix in health and in gingival alterations.

Distribution of fibronectin in healthy, inflamed and drug-induced gingival hyperplasia

The distribution of fibronectin (FN) in the healthy, inflamed and hyperplastic human gingiva was investigated by indirect immunofluorescence. FN appeared as a fibrillar structure in the lamina propria of the healthy gingivae. In the inflamed specimens, FN demonstrated parallel fibres, especially in the coronal areas of the tissue. In the phenytoin gingival overgrowth, tissue FN was observed as thin fibres with variable length. The thin fibres gave the appearance of penetrating the basement membrane of the epithelium. Cyclosporin A gingival enlargement could be differentiated by phenytoin lesions because of the higher length and the parallel distribution of the FN. Finally, FN was observed in the nifedipine gingival overgrowth, where a microfibrillar delicate network gave the appearance of a "cloud"-pattern of distribution. In all of the specimens, blood vessels and nerves could not be stained. These findings show that FN distribution could differentiate the structure of the gingival lesions.

On the mechanism of drug-induced gingival hyperplasia

Proposed mechanisms of the side effect of drug-induced gingival hyperplasia are reviewed. Hypotheses with regard to inflammation from bacterial plaque, increased sulfated glycosaminoglycans, immunoglobulins, gingival fibroblast phenotype population differences, epithelial growth factor, pharmacokinetics and tissuebinding, collagenase activation, disruption of fibroblast cellular sodium/calcium flux, folic acid and a combination hypothesis are evaluated.

Effect of phenytoin and nifedipine on collagen gene expression in human gingival fibroblasts

Phenytoin (PHT), a widely used anticonvulsant, and nifedipine (NF), an anti-anginal drug, cause clinically similar gingival overgrowths in some patients. The aim of this work was to investigate their effects on collagen and protein synthesis and cellular proliferation in normal human gingival fibroblasts in vitro. Gingival fibroblasts were cultured from biopsies taken from three healthy individuals during operations on maxillary canines and incubated with various concentrations of NF (100 and 200 ng/ml) and PHT (5 and 10 micrograms/ml) for up to 7 days. The results showed that NF and PHT have a specific effect in reducing total protein and collagen synthesis but do not influence cell proliferation in healthy gingival fibroblasts in vitro. In addition the level of mRNA for type I collagen was decreased after incubation of the cells with the drugs for 1 or 2 days. The decrease in the level of type I collagen mRNA seemed to be specific since the level of type IV collagenase mRNA used as a reference RNA did not decrease.

Dietary ascorbic acid normalizes diabetes-induced underhydroxylation of nascent type I collagen molecules

Nascent collagen alpha chains (types I and III) isolated from diabetic rat skin were shown to be underhydroxylated, an underhydroxylation normalized (type I) or partially corrected (Type III) by dietary ascorbic acid. Increased hydroxylation occurred concomitantly with reduced intracellular procollagen degradation and increased production of nascent collagen molecules, both contributing to an increased total skin collagen mass. Overall, by correcting a defect (underhydroxylation) in a posttranslational event and by increasing collagen production, dietary ascorbic acid improved the collagen status of a diabetes-perturbed connective tissue.

Phenytoin-induced hyperplasia of the pre-eruptive stage. Report of a case

A patient with a rare manifestation of phenytoin-induced hyperplasia is reported. Severe maxillary and mandibular gingival hyperplasia occurred prior to the eruption of the dentition and without evidence of any predisposing local irritation factors.

Ultrastructural quantitation of connective tissue changes in phenytoin-induced gingival overgrowth in the ferret

The gingival overgrowth obtained after maintaining ferrets on PHT appeared to be due entirely to the effect of the drug, for inflammation induced by banding had no influence on the action of PHT in eliciting the overgrowth. The significant change observed was an increase in relative volume of interstitial material (ground substance) in response to PHT. Although there was no appreciable alteration in numbers of cells present in the lesion, PHT had a significant effect on the ultrastructure of fibroblasts. These cells showed a decrease in the relative volume of phagosomes, although organelles concerned with synthesis (the rough endoplasmic reticulum and Golgi zones) were not affected. This suggests that the relative increase in ground substance may reflect decreased breakdown of extracellular material within fibroblasts, while synthetic activity is maintained at a constant level. As a consequence, there is an increase in connective tissue volume--an increase which is manifested as an overgrowth.

Increased collagen synthesis by gingival fibroblasts derived from a Papillon-Lefévre patient

Both skin and gingival fibroblasts in the Papillon-Lefévre patient synthesized Type I and Type III collagen in a ratio very similar to fibroblasts of control cells. The only abnormality appeared to be elevated levels of collagen and protein synthesis by gingival cells derived from the Papillon-Lefévre patient.

Gingival matrix collagen in chronic periodontitis

The isolation and characterization of cyanogen bromide peptides derived from the human gingival collagen of patients with chronic periodontitis revealed the presence of both Type I and Type III collagens in this tissue. The amount of TYPE III collagen, however, was found to be lower than that in normal gingival tissue. In addition, a non-collagenous protein fraction, accounting for approximately 20% of the insoluble matrix, was relatively rich in acidic, hydrophobic, and hydroxy-containing amino acids. Amino acid analysis, likewise, revealed qualitative and quantitative differences between the normal and diseased tissues.