DESCRIPTION (provided by applicant): Diabetes increases the risk of severe infections, including periodontitis. Maintenance of homeostasis and tissue health of the periodontium is complicated by overgrowth of specific pathogens. The innate immune response prevents invasion and limits the complexity of the infection. When disease occurs as a complication of systemic disease as in diabetes, tissue damage results from the host response (phagocyte mediated tissue injury), which provides a microenvironment that favors bacterial growth and the chronicity of the lesion. Dysregulated inflammatory/immune reactions have been implicated in the pathogenesis of the complications of diabetes, particularly periodontitis and cardiovascular diseases. Tissues exposed to the external environment and significant bacteria load, such as the periodontium, are at increased risk. The return of inflamed tissues to health and homeostasis is mediated by endogenous agonists that promote resolution of inflammation. The cellular and molecular mechanisms responsible for the resolution of periodontal inflammation are beginning to be mapped. These same proresolution agonists enhance host cell mediated antibacterial activity. Precursor fatty acid substrates from cells (arachidonic acid) and dietary sources (omega-3 fatty acids) yield lipid mediators (lipoxins and resolvins, respectively) that counter-regulate pro-inflammatory signals. Systematic temporal study of periodontal infection and resolution in tissues of people with diabetes is of paramount importance in the treatment of bacterially initiated periodontal disease. The goal of this competing renewal R01 proposal is to determine the impact of infection in resolution circuits of inflammation in people with diabetes. Our novel hypothesis is that restoration of resolution pathways by exogenous administration of resolving molecules will resolve periodontal inflammation and restore homeostasis modifying the composition of the microflora. In this proposal, we will investigate the mechanism of action of phagocyte interactions in the periodontium invoking innate antimicrobial activity and enhanced clearance of pathogens in people with diabetes.