How epigenetics and miRNA affect gene expression in dental pulp inflammation: A narrative review

Pulpitis, an inflammatory condition of the dental pulp, typically arises due to caries. It can remain asymptomatic for extended periods, complicating its diagnosis. The inflammatory response induced by bacterial invasion encompasses both cell-mediated and humoural immunity, accompanied by neural and vascular changes. The primary aim of inflammation is to eradicate invading pathogens from the pulp. However, failure to eliminate pathogens may result in necrosis of the pulp. Before direct bacterial contact with cells occurs, the pulp initiates protective responses like the formation of tertiary dentine. The interaction between bacterial surface proteins and specific receptors on pulp cells, primarily odontoblasts and dendritic cells, activates intracellular signalling pathways. These cascades, mediated by transcription factors, regulate gene expression and subsequent protein synthesis, thereby modulating the inflammatory response. In addition to proinflammatory and anti-inflammatory mediators, microRNAs and epigenetic modifications play a key role in gene expression in dental pulp. Epigenetic changes including DNA methylation and histone modifications can occur within the pulp.

Dental pulp inflammation represents a highly intricate network of signalling pathways, messenger molecules and cellular interactions. The ongoing research continuously expands our understanding of these processes. The objective of this review is to investigate mechanisms of dental pulp inflammation, concentrating on the regulation of gene expression. This consists of transcription factors, microRNAs, epigenetic modifications and mitochondrial DNA, among others. This review aims to highlight recent findings about biomolecular and epigenetical mechanisms of pulpitis as well as their role in gene expression.

Pulp inflammation is a complex series of events happening on a molecular and cellular level. Even though the pulp tissue is hardly examined in vivo, laboratory studies offer great new insights and potential for our understanding of its inflammatory mechanisms. Recognition of bacterial components by pulp cells is the initiator of overlapping signalling pathways that will eventually lead to gene activation or repression. Specific genes might be activated, resulting in the production of messenger molecules like cytokines and chemokines. Trending topics of medicine like microRNA and epigenetics are also discussed in the context of dentistry. This knowledge could be used to develop new therapeutics in endodontics.