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Background: Periodontitis has been associated with several medical conditions. Forsome of these medical conditions, periodontitis has been hypothesized to share important pathogenetic mechanisms. Recently, advances in biochemistry have led to the identification of novel inflammatory mediators implicated in some of the chronic medical conditions associated with periodontitis. However, there is a little to no evidence on the systemic levels of such biomarkers in periodontitis. Potential identification of these systemic inflammatory mediators in periodontitis would offer additional support to the potential periodontal-systemic disease association.Methods: 33 systemically healthy persons, 16 periodontally healthy individuals and 17chronic periodontitis patients, were recruited as part of an observational study. Peripheral blood samples were collected from each participant by venipuncture. Blood samples were collected twice from each participant, at two different time points 1-2 weeks apart. For 10 out of the 17 periodontitis patients who returned for reevaluation, following periodontal treatment, a third blood sample was collected. Samples were processed to prepare serum, aliquoted and stored at -80 °C. Aliquoted serum samples were analyzed for HMGB-1, S100A12, chemerin, BAFF, FGF-21 and ADMA levels using commercially available ELISA kits following the manufacturer’s instructions and performing the assay in duplicate wells.Results: The results showed that the average serum levels of HMGB-1 and chemerinwere statistically significantly higher in patients with periodontitis compared to healthysubjects. The levels of S100A12, BAFF, FGF-21 and ADMA were found to be elevatedin the patient group compared to the control group but the differences did not reachstatistical significance. Statistical analysis of the subgroup of patients that received nonsurgical periodontal treatment showed that the systemic levels of all inflammatorymediators, except for FGF-21, decreased following scaling and root planing. However the differences were not statistically significant.Conclusion: Chronic periodontitis patients were found to have significantly higher serumlevels of HMGB-1 and chemerin compared to periodontally healthy controls. The levelsof the remaining 4 inflammatory mediators in the patient group were higher but notstatistically significantly greater than the control group. The above findings support theexisting evidence of an association between periodontitis and other systemicdiseases/conditions and should form the impetus for more extensive research towards the identification of systemic biomarkers for periodontitis.

Previous studies have shown that inflammation is a key factor in determining scar formation in cutaneous fetal wounds. In a fetal mouse model, sterile wounds generated on embryonic day 15 (E15) have little to no inflammation and heal scarlessly, while wounds generated on embryonic day 18 (E18) have inflammation and heal with a scar. The mechanisms leading to age-related differences in inflammation and healing are not fully understood. Alarmins, which comprise a group of endogenous danger signals, have been implicated in promoting inflammation in various organ systems and disease processes. This study evaluates the role of a specific alarmin, high mobility group box 1 (HMGB-1), in cutaneous fetal wound healing. HMGB-1 is a non-histone architectural DNA binding protein localized within the nucleus of the cell. However, it can be released by both passive and active mechanisms. Passive release into the extracellular matrix occurs as a result of cell injury or necrosis. While active secretion is described as a capability of several cell types, including immune cells. Once in the extracellular space, HMGB-1 stimulates inflammation by binding to RAGE (receptor for advanced glycation end products) or toll-like receptors present on inflammatory cells.This is the first study to evaluate the role of HMGB-1 in the process of fetal wound healing. We hypothesized that alterations in the expression or release of HMGB-1 between early and late gestation fetal wounds contribute to the differences seen in healing outcomes. To begin, comparisons of HMGB-1 expression in fetal wounds that heal scarlessly and wounds that heal by scar formation were made. Later experiments tested the ability of HMGB-1 to induce scar formation in E15 wounds that have previously been shown to heal scarlessly. Finally, mechanisms of action were explored to decipher how HMGB-1 affects fibroblasts, the cells ultimately responsible for scar formation.Immunohistochemical staining of E15 and E18 skin revealed age-related differences in HMGB-1 expression patterns in both unwounded and wounded skin. As compared to E15 basal keratinocytes, basal keratinocytes of E18 skin expressed higher nuclear HMGB-1 staining and demonstrated a more substantial loss of nuclear staining after injury, suggesting that HMGB-1 is released to a greater extent in E18 wounds. Furthermore, E15 wounds treated with HMGB-1 could be induced to heal by fibrosis with differences seen in both the amount and quality of collagen present within the scar. Age-dependent differential release of HMGB-1 from fetal keratinocytes during wound healing and the capability of HMGB-1 to induce scar formation in E15 wounds that naturally heal scarlessly were found. These results support the hypothesis that alterations in expression or release of HMGB-1 contribute to the difference seen in healing outcome between early and late fetal wounds. This study suggests both the timing and degree of extracellular HMGB-1 release are potential factors in determining whether scarless or fibrotic wound healing will result. In light of these findings, HMGB-1 remains a viable therapeutic target for optimizing wound repair.

Estrogen receptor (ER) is a ligand-inducible enhancer protein that is a member of nuclear hormone receptor super family. Estrogen receptors share a highly conserved structure with other members of the steroid receptor super family and a common mechanism, regulating gene transcription. Estrogen receptors reside in the nucleus and in the absence of hormone signal bind to other proteins. However, in the presence of hormone, the receptor dissociates from the other proteins and dimerizes. The dimeric form of estrogen receptor is the active form which binds to a specific DNA sequence, known as the estrogen response element (ERE) in the regulatory region of the target gene. The estrogen response element (ERE) consists of asymmetric or pseudo asymmetric, palindromic repeat of two half-site sequences (cHERE) 5’-AGGTCA-3’, separated by 3bps. HMG domain proteins are architectural proteins involved in chromatin function and have been shown to stabilize the ER/ERE binding. One aims of this thesis is to determine how differences in spacer length between the ERE half-site affect on ER binding affinity in the presence and absence of the coactivator protein, HMGB-1. The binding affinity and selectivity of the two forms of the estrogen receptor (á and â) and glucocorticoid receptor (GR) for cHERE, in three different orientations (direct repeats, inverted repeats and everted repeats) were studied by using the gel mobility shift assay (EMSA). ERs, in contrast to GR, showed a strong cooperativity when interacting with direct repeats, inverted repeats as well as everted repeats.