Primary Hypertension and Periodontal Diseases: Possible Link Via Angiotensin II

Objectives: Immune system has been known to play a substantial role in the development of primary hypertension (PH). Hypothetically, the dysregulation of immune responses should have a close association with periodontal diseases. In the present study, we would like to investigate how PH may affect the development of periodontal disease.
Methods: B6.129P2-Nos3^tm1/Nju mice were used as PH mouse model; periodontitis was established by applying mixed bacterial. Bone resorption was measured by different stainings. Toll-like receptor 4 (TLR4)-related cytokine and angiotensin (AngII) expressions were measured by qRT-PCR and ELISA in the lesion area. Dendritic infiltration was tested by immunofluorescence staining in the periodontitis lesion area. Experimental data were analyzed with student's t-test and reported as mean ± SD of triplicate independent samples. Mann-Whitney U test was used for the non-parametric test. P values <0.05 or U values >1.96 were considered significant.
Results: Periodontal bone resorption was significantly increased in the hypertensive-periodontitis mice. The infiltration of dendritic cells was significantly increased in the periodontitis lesion area. High expression of TLR4 was also observed in the periodontitis lesion area. The qPCR and ELISA result demonstrated that AngII could promote the expression of TLR4-related inflammatory factors in the periodontal lesion area.
Conclusions: Our study showed that PH could affect periodontal diseases via AngII, which will regulate the expression and function of TLR4 and the continued immune responses in the lesion area.