Ncor1 Deficiency Promotes Osteoclastogenesis and Exacerbates Periodontitis.

Area of Science:

• Immunology and Oral Biology
• Molecular and Cellular Biology

Background:

• Nuclear receptor corepressor 1 (Ncor1) is a key regulator in metabolism, inflammation, and circadian rhythms.
• The specific role of Ncor1 in the pathogenesis of periodontitis remains largely uncharacterized.

Purpose of the Study:

• To investigate the role of Ncor1 in experimental periodontitis.
• To elucidate the underlying molecular mechanisms of Ncor1's function in periodontitis using myeloid cell-specific Ncor1-deficient mice.

Main Methods:

• Generation of myeloid cell-specific Ncor1 knockout (MNKO) mice and induction of experimental periodontitis.
• Assessment of alveolar bone resorption via histology and micro-computed tomography.
• Flow cytometry for myeloid cell analysis, RNA sequencing for gene expression profiling, and molecular assays (Co-IP, ChIP, dual luciferase) to determine molecular interactions.

Main Results:

• MNKO mice exhibited significantly increased alveolar bone resorption and osteoclastogenesis compared to littermate controls (LC).
• A higher percentage of myeloid cells, particularly neutrophils, was observed in the gingival tissues of MNKO mice.
• Ncor1 deficiency led to differential expression of CCAAT enhancer binding protein alpha (Cebpα); NCOR1 was found to interact with PPARγ and HDAC3 to regulate Cebpα transcription.

Conclusions:

• Ncor1 deficiency promotes osteoclast and neutrophil formation, exacerbating experimental periodontitis.
• Ncor1 regulates Cebpα transcription through the PPARγ pathway, influencing osteoclast differentiation and alveolar bone loss in periodontitis.