elastin and Periodontal-Diseases

Parvimonas micra are gram positive anaerobic cocci isolated from the oral cavity and frequently related to polymicrobial infections in humans. Despite reports about phenotypic differences, the genotypic variation of P. micra and its role in virulence are still not elucidated. The aim of this study was to determine the genotypic diversity of P. micra isolates obtained from the subgingival biofilm of subjects with different periodontal conditions and to correlate these findings with phenotypic traits. Three reference strains and 35 isolates of P. micra were genotyped by 16S rRNA PCR-RFLP and phenotypic traits such as collagenase production, elastolytic and hemolytic activities were evaluated. 16S rRNA PCR-RFLP showed that P. micra could be grouped into two main clusters: C1 and C2; cluster C1 harbored three genotypes (HG1259-like, HG1467-like and ICBMO583-like) while cluster C2 harbored two genotypes (ATCC33270-like and ICBMO36). A wide variability in collagenolytic activity intensities was observed among all isolates, while elastolytic activity was detected in only two isolates. There was an association between hemolytic activity in rabbit erythrocytes and cluster C2. There was an association between hemolytic activity in rabbit erythrocytes and cluster C1. Although these data suggest a possible association between P. micra genetic diversity and their pathogenic potential, further investigations are needed to confirm this hypothesis.

Topics: Animals; Biodiversity; Cluster Analysis; Collagenases; DNA Fingerprinting; DNA, Bacterial; DNA, Ribosomal; Elastin; Erythrocytes; Genotype; Gingiva; Gram-Positive Bacteria; Hemolysis; Humans; Periodontal Diseases; Polymorphism, Restriction Fragment Length; Rabbits; RNA, Ribosomal, 16S

Williams Beuren syndrome (WBS) is an unusual hereditary connective tissue disease caused by a microdeletion at position 7q11-23 and a haploinsufficiency at the elastin gene. The most frequent specific features are elf-like face, alteration of cognitive functions and cardiovascular diseases including isolated supravalvular aortic stenosis. A number of clinical findings have been reported, but none of the studies evaluating this syndrome consider the oral cavity. It is equally surprising that the gingival tissue, which carries a perfectly structured elastic fibre network, has not yet been investigated. It is important to verify whether subjects affected by WBS are more susceptible to periodontal disease than healthy subjects who are not that much affected, for periodontal disease may have deleterious effects on the cardiovascular system.. In an attempt to address this issue, the oral manifestations of 8 patients (ages from 5 to 12 years) with WBS have been investigated: dental examination, periodontal examination (gingival phenotype, plaque control record, gingival index, bone quality).. All patients had oral parafunction, tooth number abnormalities and malocclusions. Average gingival height and width were greater than normal. Plaque index was always very high except for one patient, but the gingival inflammation was not linked to the quantity of clinical plaque index. There was no obvious loss of attachment.. As with collagen, elastin is a structural macromolecule of the gingiva. These components play an important role in gingival function and in the resistance of the periodontium to daily aggressions. Unlike genetic diseases characterized by impairment of collagen macrofibrils, it is suggested that the hemizygous gene encoding elastin does not result in periodontal disease. In addition there is an existence of a possible concordance between the elastin gene haploinsufficiency and the periodontal phenotype. There might be some adaptive process to this deficiency.

Topics: Anodontia; Child; Child, Preschool; Elastin; Female; Gingival Diseases; Humans; Male; Malocclusion; Periodontal Diseases; Periodontal Index; Williams Syndrome