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PPAR-γ, RXR-α, and VDR Expression in Gingival Tissues of Patients with Grade B and Grade C Periodontitis: A Cross-Sectional Clinical Immunohistochemistry Study

Year: 2026
Type: article
Study design: Observational Study
Abstract: Background/Objectives: Periodontitis grade reflects differences in disease progression and risk, yet the underlying host-response signatures that distinguish grade B from grade C are not fully elucidated. Nuclear receptors involved in inflammation and tissue homeostasis may contribute to these biological differences. The present study aimed to evaluate the expression of peroxisome proliferator-activated receptor-γ (PPAR-γ), retinoid X receptor-α (RXR-α), and vitamin D receptor (VDR) in gingival tissues from periodontally healthy individuals and from patients with grade B and grade C periodontitis, with the primary comparison focusing on grade-related differences within the same disease stage (stage 3). Methods: Forty-five participants were allocated to three groups: Group 1, healthy controls; Group 2, stage 3 grade B periodontitis; and Group 3, stage 3 grade C periodontitis. Clinical parameters, including plaque index (PI), gingival index (GI), and clinical attachment loss (CAL), were recorded. Fibroblast and inflammatory cell density, and immunohistochemical expression levels of PPAR-γ, RXR-α, and VDR were assessed on histological sections. Results: Compared with healthy controls, both periodontitis groups showed lower fibroblast cell counts and higher inflammatory cell counts. PPAR-γ expression was significantly higher in Group 3 than in the other groups, whereas RXR-α and VDR expression were higher in Group 1 than in Groups 2 and 3. Conclusions: These findings suggest that increasing disease grade within stage 3 periodontitis is associated with increased PPAR-γ expression, whereas RXR-α and VDR expression primarily distinguish healthy from diseased gingival tissues. This nuclear receptor profile may help explain biological differences between healthy, grade B and grade C periodontitis and support future risk-stratified host-modulatory approaches.
Language: English
Subfield: Periodontics
Field: Dentistry
Open Access status: gold
Estimated APC paid: $3,137
OpenAlex ID: W7154264016
FWCI: 5.945
Cites: 40
Cited by: 1
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