Molecular characteristics of periodontal health: Collagens: Defining the healthy human gingival collagen transcriptome: Defining the healthy human gingival collagen transcriptome.

BACKGROUND: Defining periodontal health has been an ambitious and complex goal. The numerous and varied definitions of what constitutes periodontal health have resulted in a collection of subjective and unreliable clinical findings to diagnose and classify periodontal health and disease. The aim of this study was to fundamentally delineate the molecular characteristics of healthy periodontal tissues in men and women as they age, using the most abundant connective tissue component: Collagens. METHODS: Healthy gingival biopsies were separated into "young" (aged 18-35 years, five men/five women) and "old" (≥60 years, five men/four women) age groups depending on biological sex. RNA was extracted and next-generation RNA sequencing was performed using Unique Molecular Identifiers. Collagen gene expression was determined and quantified for young and old, male and female individuals. RESULTS: Twenty-six human collagens were identified in healthy gingival tissues. In general, age and biological sex affected expression of collagen α-chain transcripts. Ten of the 26 human gingival collagen genes formed a unique pattern for gingival health. More specifically, the expression of fibrillary (types I and III), fibril-associated collagens with interrupted triple-helices (FACIT) and FACIT-like (types XII, XIV, and XX), network-forming (types IV and VI), transmembrane (type XVII), and multiplexin (types XV and XVIII) collagens, taken together, exhibited a distinct pattern of characteristics for gingival health that was independent of age or biological sex. CONCLUSIONS: Although specific α-chains of the collagen transcriptome were affected by age and biological sex, the compilation of various collagen transcripts can be used to define gingival health that is independent of age and biological sex.

Proteomic analyses of human gingival and periodontal ligament fibroblasts.

BACKGROUND: Although human gingival fibroblasts (hGFs) and human periodontal ligament fibroblasts (hPDLFs) exhibit numerous phenotypic similarities, it has been suggested that the secretory and behavioral differences, which exist between these cell types, are a result of the membrane protein composition of these cells. METHODS: Four matched pairs of hGFs and hPDLFs were cultured. Before confluence, membrane-bound and -associated proteins from cells of the fourth passage were extracted. The processed protein samples were evaluated using capillary-liquid chromatography-nanospray tandem mass spectrometry. Global protein identification was performed on an orbitrap mass spectrometer equipped with a microspray source operated in positive ion mode. Proteome software was used to validate protein identifications derived from tandem mass spectrometry sequencing results. RESULTS: Four hundred fifty proteins were common to both hGFs and hPDLFs. Of the proteins identified, 214 were known membrane-bound or -associated proteins, and 165 proteins were known nuclear-associated proteins. Twenty-seven proteins, identified from the 450 proteins, common to both hGFs and hPDLFs, were detected in statistically significant greater quantities in either hGFs or hPDLFs. More specifically, 13 proteins were detected in significantly greater quantities in hGFs, whereas 14 proteins were detected in significantly greater quantities in hPDLFs. CONCLUSIONS: Distinct differences in the cellular protein catalog may reflect the dynamic role and high energy requirements of hGFs in extracellular matrix remodeling and response to inflammatory challenge as well as the role of hPDLFs in monitoring mechanical stress and maintaining tissue homeostasis during regeneration and remineralization.

An investigation of the relationship between systemic bone density and clinical periodontal status in post-menopausal Asian-American women.

OBJECTIVES: The relationship between osteoporosis and periodontal disease is not understood. The aim of this study was to examine the association between bone mineral density (BMD) and periodontal status in a population of Asian-American women. DESIGN: Cross-sectional investigation of the association between systemic BMD and periodontal status. PARTICIPANTS: Thirty post-menopausal, dentate, Asian-American women who were screened for osteoporosis and chronic periodontitis. METHODS: BMD of the os calcis, composed primarily of trabecular bone, was assessed by DEXA scanning. Periodontal assessments included tooth loss, plaque index, probing depths, and clinical attachment levels. Correlation and regression analyses were conducted to determine the strength of associations between BMD and clinical parameters. RESULTS: Statistically significant negative correlations were found between BMD and tooth loss and BMD and clinical attachment loss (p < 0.01). Those with normal BMD had lost, on average, 6.8 teeth, compared to 10.5 teeth in the osteopenic group, and 16.5 teeth in the osteoporotic group (p < 0.001). CONCLUSIONS: Decreasing BMD was associated with increased clinical attachment loss and tooth loss that was independent of plaque scores. These data support an association between BMD and periodontal status.