Abstract
BACKGROUND: Pulp inflammation is one of the primary side effects of dental caries. MDA5 (melanoma differentiation-associated protein 5) and RIG-I (retinoic acid-inducible gene I) are two intracellular receptors that activate inflammatory transcription factors via recognition of damage-associated molecular patterns (DAMPs) and pathogen-associated molecular patterns (PAMPs). The aim of this in vitro study was to evaluate expression levels of MDA5 and RIG-I in inflamed versus healthy pulps. MATERIALS AND METHODS: mRNA levels of MDA5 and RIG-I were assessed in 50 inflamed versus 50 healthy pulps. Total RNA extraction and cDNA synthesis were performed and expression levels of MDA5 and RIG-I were evaluated using real-time PCR. RESULTS: The results revealed that the mRNA levels of MDA5, but not RIG-I were significantly different in inflamed compared with healthy pulps. Furthermore, there was no significant difference in RIG-I expression taken from inflamed or healthy pulps of men and women. On the other hand, MDA5 expression was significantly upregulated in men, compared to women with pulpitis. CONCLUSIONS: The results suggest that MDA5 participates in the inflammation of pulps following caries. In addition, it may be hypothesized that MDA5 expression can be sex-dependent in the inflamed pulps.