Inflammation-related Genes and miRNAs Expression in Localized Aggressive Periodontitis

Objectives: Localized aggressive periodontitis (LAP) is an inflammatory disease that mainly affects children and may result in bone destruction and tooth loss. Our previous data has demonstrated that LAP patients produce more pro-inflammatory cytokines than health controls (HC) in response to TLR4 and TLR2 ligation. In this work, our objective is to identify altered gene and miRNA expression in peripheral blood mononuclear cells (PBMCs) from patients with LAP.
Methods: PBMCs were isolated from peripheral blood and RNA was extracted and analyzed for both gene and miRNA expression before and after clinical treatment.
Results: Based on the results from a TLR gene expression PCR array, we selected some differentially expressed genes and miRNAs for validation with qRT-PCR. PBMCs obtained from 29 HC, 29 LAP at baseline, 12 LAP 3 months after treatment, and 15 LAP 6 months after treatment were analyzed. IRAK1 and FOS expressions were significantly upregulated in LAP patients at baseline compared to HC (p < 0.05) but were not significantly modified after treatment. These proteins are recruited after TLR activation and collaborate to inflammation. Expression of IL10, an anti-inflammatory gene, was 3.74-fold higher (p < 0.05) in LAP patients 6 months after treatment, showing that treatment induces regulation of inflammation. TICAM1, which encodes an adaptor protein of TLR-pathway, was upregulated in LAP baseline and 6 months after treatment. MiRNA expression showed that miR-9-5p, miR-203a-3p and miR-183-5p were upregulated on LAP baseline but not after treatment. These miRNAs were previously shown to be upregulated after TLR activation. MiR-147a, also involved with TLR-signaling pathway, was upregulated in LAP patients 3 and 6 months after treatment.
Conclusions: LAP patients regulate important genes and miRNAs related to inflammation, which may contribute to disease susceptibility. Disease treatment also modulate some changes in their expression.