Detection of nuclear receptors in gingival samples of diabetic and nondiabetic periodontitis patients

Background: Diabetes and periodontitis are two chronic inflammatory diseases sharing specific etiopathogenetic mechanisms, and both cause severe inflammation and destruction. Aims: The present study aimed to determine the receptor expressions of peroxisome proliferative-activated receptor (PPAR)-gamma, retinoid X receptor (RXR)-alpha, vitamin D receptor (VDR), and nuclear factor kappa B (NF-kappa B) expressions in healthy gingiva and diseased gingival samples with or without diabetes. Methods: Forty-five participants as (1) healthy controls (C), (2) periodontitis group (P), and (3) diabetes and periodontitis group (DP) were enrolled. Plaque index (PI), gingival index (GI), probing depth (PD), clinical attachment levels (CAL), and bleeding on probing (BOP) were recorded in all participants. Two gingival biopsies from each participant were obtained, and one underwent histological tissue processing while the other underwent qRT-PCR analysis of nuclear receptors. Inflammatory and fibroblast cell counts, PPAR-gamma, RXR-alpha, VDR, and NF-kappa B were evaluated. Results: Fibroblast cells were lowest in the DP group and highest in the healthy group. PPAR-gamma, VDR, RXR, and NF-kappa B expressions were higher in the healthy controls in the qRT-PCR analysis and similar in the other groups. Immunohistochemistry analysis also showed similar results. Conclusion: qRT-PCR results concluded that healthy gingival samples had higher PPAR-gamma, RXR, VDR, and NF-kappa B expressions, and immunohistochemistry findings supported the results. In addition, healthy gingiva contained higher fibroblast cells and lower inflammatory cells.