Papel dos receptores farmacológicos AT1 e AT2 da Angiotensina II em doença periodontal induzida: aspectos moleculares

Abstract

The renin angiotensin system (RAS) is of great importance for water balance and regulation of blood pressure in the body, in addition to being associated with the stimulation of proinflammatory pathways. Its main peptide is angiotensin II, which interacts mainly with type 1 (AT1) and type 2 (AT2) receptors. An interrelationship was found between cardiovascular diseases and periodontitis. This study aimed to evaluate the molecular aspects in mice subjected to an experimental model of periodontal disease, observing the influence of Ang II type 1 (AT1(-)) and Ang II type 2 (AT2(-)) receptors on periodontitis. Methods: Experimental periodontitis was induced by placing a ligature with 5.0 nylon thread around the upper left second molar of AT1(-), AT2(-) and wild-type (WT) knockout mice, subdivided into 2 groups for each strain: without ligation and ligation, totaling six groups: three controls and three experimental. After 15 days of disease induction, the animals were euthanized. In order to evaluate whether genetic variations would have an influence on periodontal disease, analyzes of cytokines were carried out, peptides and enzymes were analyzed from gingival tissues by ELISA and RT-PCR. Results: WT and AT2(-) animals showed similar results in relation to the cytokines IL-1β, IL-6, TNF-α, with increased levels compared to healthy ones (p < 0.001). There were significant differences in IL-β between the AT1(-)-L and WT-L groups (p < 0.05), and in IL-6 and TNF-α the AT1(-)-L groups showed significant differences (p < 0.001) both when compared to the WT-L and AT2(-)-L groups. IL-10 levels were higher in WT-L (p < 0.01), while the AT2(-) and AT1(-) groups did not show significant changes in relation to this cytokine. There were significant differences in Angiotensin II between the AT2(-)-NL and AT2(-)-L groups (p < 0.01); and in Angiotensin 1-7 between the AT1(-)-L and AT2(-)-L groups (p < 0.05). For TLR2 there were differences between the WT-NL/WT-L groups (p < 0.05); AT1(-)-NL/AT1(-)-L (p < 0.01) and AT2(-)-NL/AT2(-)-L (p < 0.01). For the MAS receptor there were differences between the WT-NL/WT-L (p < 0.001) and AT2(-)-NL/AT2(- )-L (p < 0.001) groups, and also in relation to the WT-L group /AT1(-)-L (p < 0.001) and AT1(-)-L/AT2(-)-L (p < 0.001). For the expression of ACE and ACE2 peptides, there was a statistical difference only for ACE between the types of WT-NL/WT-L groups (p < 0.001). Conclusion: The animals in the AT1(-) group showed less inflammation than the other diseased lines, as well as a lower expression of the Mas and Ang 1-7 receptor. Furthermore, animals from the WT and AT2(-) groups demonstrated similar results in several analyses, showing that the blockade of the AT1 receptor, on molecular effects, is more positive.