Evaluation of the presence and stimulation of sympathetic nervous system in the periodontium and the influence of noradrenaline in Galleria mellonella infected by Porphyromonas gingivalis: Uncovering the relationship between stress and periodontitis.

Abstract

In recent decades the negative relationship between stress and periodontal disease has been observed. The literature demonstrates that stress aggravates periodontal disease by activation of the central nervous system with release of cortisol, behavior 's alterations, and stimulation of the sympathetic nervous system (SNS) with catecholamines release. The SNS has influence on several factors associated with the pathogenesis of periodontal disease as the inflammatory host response, the periodontal resident cells and periodontopathogenic bacteria. Thus, the aim of this study is to evaluate the presence and influence of the SNS in the stimulation of periodontal vasculature, as well as the influence of noradrenaline (hormone released by the SNS) on the expression of virulence factors from Porphyromonas gingivalis (Pg) and on the immunological response of Galleria mellonella. Genetically modified mice labeled by the fluorescent protein eGFP in the SNS fibers will be used to describe the presence of these fibers in the periodontal tissues around the lower first molar region. Isoproterenol (ISO-alpha-adrenergic agonist) will also be administered to wild-type mice and the influence of sympathetic activation on angiogenic stimulation in periodontal tissues will be assessed by immunohistochemistry (VEGF-a, VEGFR2, AML and CD34), and the presence of norepinephrine transporter (NET) in periodontal region, by imunofluorescence. Finally, the influence of noradrenaline on the virulence factors of Pg and on the immunological response of Galleria mellonella infected by this periodontopathogen will be evaluated through survival curve, hemocyte count, lysozyme test and molecular biology for the evaluation of fimbriae, gingipain, cecropin and gloverin genes. The data will be submitted to appropriate statistical analysis. (AU)