Angelo Mariotti

Sex steroid hormones and cell dynamics in the periodontium.

The biological changes that occur in tissues of the periodontium during puberty, the menstrual cycle, pregnancy, menopause, and oral contraceptive use have heightened interest in the relationship between sex steroid hormones and periodontal health. These clinical observations coupled with tissue specificity of hormone localization, identification of hormone receptors, as well as the metabolism of hormones have strongly suggested that periodontal tissues are targets for androgens, estrogens, and progestins. The etiologies of periodontal endocrinopathies are diverse; nonetheless, periodontal pathologies may be a consequence of the actions and interactions of sex steroid hormones on specific cells found in the periodontium.

Endocrinology of sex steroid hormones and cell dynamics in the periodontium

Numerous scientific studies assert the existence of hormone-sensitive periodontal tissues. Tissue specificity of hormone localization, identification of hormone receptors and the metabolism of hormones are evidence that periodontal tissues are targets for sex steroid hormones. Although the etiologies of periodontal endocrinopathies are diverse, periodontal pathologies are primarily the consequence of the actions and interactions of sex steroid hormones on specific cells found in the periodontium. This review provides a broad overview of steroid hormone physiology, evidence for the periodontium being a target tissue for sex steroid hormones and theories regarding the roles of sex steroid hormones in periodontal pathogenesis. Using this information, a teleological argument for the actions of steroid hormones in the periodontium is assessed.

Experimental Gingivitis in Women Using Oral Contraceptives

Oral contraceptives (OC) have historically been considered a risk factor for gingival diseases. We set out to investigate this premise further, given that, over recent years, hormone concentrations in OC have been substantially reduced. Using a prospective, split-mouth, experimental gingivitis model, pre-menopausal women either taking (n = 14) or not taking (n = 16) OC refrained from all oral hygiene practices in one maxillary (test) quadrant while continuing to perform normal oral hygiene activities in the contralateral (control) quadrant. Mean increases in plaque index (PI), gingival index (GI), and gingival crevicular fluid (GCF) volume from days 0 to 21 were significant in test quadrants (P < 0.05) but did not differ regardless of whether subjects received OC (P > 0.05). PI, GI, and GCF volume did not vary in control quadrants over the course of the study (P > 0.05). Analysis of these data suggests that current OC formulations do not affect the inflammatory response of the gingiva to dental plaque.

Periodontal disease in men

In relation to periodontal diseases associated with sex-steroid hormones, men have been the forgotten sex. It is not surprising that there has been less scrutiny of the effects of sex-steroid hormones in men considering the more striking changes that occur in women during different periods of their life. Despite the gingival inflammatory changes reported in women, men have been reported to have a higher prevalence of destructive periodontal diseases. The information presented in this review will provide a contemporary evaluation of male susceptibility to periodontal diseases.

Physiology, pathology and pharmacology of the male reproductive system

The male reproductive system consists of the testes, a ductal system and sex accessory organs. Production of sperm by the testes combined with fluids formed by the sex accessory organs (e.g. seminal vesicles, prostate and bulbourethral glands) produce a secretion that supports the survival of spermatozoa and provides a medium through which they can move through the reproductive ducts (e.g. epididymis, vas deferens, ejaculatory duct and urethra) for ejaculation of viable sperm into the female reproductive tract. Summarized herein are the essentials of normal male reproductive physiology, disorders of male sexual differentiation, pharmacological therapy of common diseases of the male genitourinary tract and the impact of drugs of abuse on the male reproductive system.

Principles of endocrinology

The endocrine system plays a major role in human survival. Endocrine glands secrete chemical messengers or hormones that affect every tissue of the body, including the periodontium, during the life of the individual. As the endocrine system influences a broad assortment of biological activities necessary for life, a general understanding of the principal components and functions of this system is essential. A fundamental assessment of hormone structure, mechanism of action and hormone transport, as well as influence on homeostasis is reviewed. A concise evaluation of the functions of the central endocrine glands, the functions of the major peripheral endocrine glands (other than gonadal tissues) and the known relationships of these hormones to the periodontium is examined.

The ambit of periodontal reproductive endocrinology.

A preface on the historical background, scope and clinical importance of the effects of reproductive endocrinology on the periodontium is presented. Furthermore, deductive explanations of intuitive observations evaluating the influence of reproductive endocrinology on the periodontium are discussed.

The Future of Periodontal-Systemic Associations: Raising the Standards

Purpose of ReviewPeriodontal medicine recognizes a “bidirectional” interaction between periodontitis and systemic conditions. Unfortunately, the facile ability to publish a periodontal-systemic association, regardless of biologic plausibility or rigorous scientific scrutiny, continues without abate.Recent FindingsThe increasing number of periodontal-systemic associations corrupts the ability of dentists to distinguish which of the associations are spurious and which are valid.SummaryThe use of a Disease Association Checklist creates a register for rational assessment of current disease associations. However, to diminish the publication of spurious periodontal-systemic observational associations, editors must demand that authors follow Bradford-Hill criteria and the STROBE Statement to ensure a stringent pathway to publication.

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.

The influence of age on collagen and non-collagen protein production by human gingival epithelial cells

The effects of donor age on the proliferation and secretory phenotype of cultured human gingival epithelial cells were investigated. Pure cultures of epithelial cells were isolated from human gingiva of old (61-75 yr) and young (18-30 yr) adults and serially cultivated in a serum-free medium at 37 degrees C in humidified air containing 5% CO2. For each experiment, cells were seeded at 150/mm2 and the medium changed every other day. Cell number, collagen and non-collagen protein production and relative collagen synthesis (percentage collagen synthesized) were determined at days 2, 4, 6 and 8. Epithelial strains from old and young adults became confluent by day 8 and there were no differences in their rates of proliferation. Likewise there was no difference in collagen production between the two groups; however, cells from elderly individuals produced significantly less non-collagen protein. Over time the decrease in non-collagen protein production ranged from 56% below the non-collagen protein levels of epithelium from young adults at day 2 to 24% below at day 8. The reduction of non-collagen protein coupled with the unchanged secretion of collagen resulted in a statistically significant increase in relative collagen synthesis by epithelial cells from elderly individuals. These differences in non-collagen protein production and relative collagen synthesis by cultured gingival epithelium of old adults suggest a selective conversion in protein secretion.