Analysis of MG1, MG2 and Lactoferrin in Individuals with Periodontitis

Objectives: to analyze the pattern of secretion and the expression of MG1, MG2 and lactoferrin in individuals with and without periodontitis. Methods: five individuals with aggressive periodontitis (GAP), 5 with chronic periodontitis (GCP) and 5 without periodontitis (GC) were selected. Periodontal exams were conducted and samples of resting and stimulated submandibular-sublingual saliva collected. Obtained volumes were measured, samples submitted to electrophoresis and analyzed on Western blots probed with specific antibodies. Results: stimulation significantly raised the volumes in all groups (GAP p = 0.01; GCP p = 0.03; GC p = 0.01) although differences were not observed among groups. In regard to the pattern of secretion, blots revealed that stimulation leaded to: an increase in MG1 expression in all groups; an increase in MG2 expression in GCP and a decrease in GAP and GC; and to an increase in lactoferrin expression in GAP and GCP, and a decrease in GC. In regard to comparison of expression among groups, blots revealed that under resting conditions, GC exhibited the highest expression of these glycoproteins, whereas GAP showed the lowest levels of MG2 and GCP of MG1 and lactoferrin. Under stimulated conditions, GC exhibited the highest expression of MG1 and MG2, whereas GAP the highest of lactoferrin. Conclusions: the pattern of secretion of these glycoproteins in the three distinct groups is complex and the reduced expression observed in GAP and GCP under resting condition, the predominant circumstance of salivary secretion during a day, indicates that these salivary constituents may play a role in the etiopathogenesis of these diseases.