Differentially Expressed Genes in Dental Pulp Tissues of Individuals With Symptomatic Irreversible Pulpitis With and Without History of COVID-19.

INTRODUCTION: Increased levels of proinflammatory markers have been reported in tissues of individuals with Coronavirus Disease 2019 (COVID-19). We hypothesize that inflamed dental pulp tissues of individuals with previous history of COVID-19 may present a differential inflammatory gene expression profile in comparison with individuals who never had COVID-19. MATERIALS AND METHODS: Dental pulp tissues were collected from 27 individuals referred for endodontic treatment due to symptomatic irreversible pulpitis. Of these, 16 individuals had a history of COVID-19 (6 months to 1 year post infection) and 11 individuals had no previous history of COVID-19 (controls). Total RNA from pulp tissue samples was extracted and subjected to RNA sequencing for comparison of differentially expressed genes (DEGs) among groups. DEGs showing log2(fold change) > 1 or < -1, and P < .05 were considered significantly dysregulated. RESULTS: RNA sequencing identified 1461 genes as differentially expressed among the groups. Of these, 311 were protein coding genes, 252 (81%) that were upregulated and 59 (19%) that were downregulated in the COVID group compared with controls. The top upregulated genes in the COVID group were HSFX1 (4.12-fold change) and LINGO3 (2.06-fold change); significantly downregulated genes were LYZ (-1.52-fold change), CCL15 and IL8 (-1.45-fold change). CONCLUSIONS: Differential gene expression in dental pulp tissues of COVID and non-COVID groups suggests potential contribution of COVID-19 on dysregulating inflammatory gene expression in the inflamed dental pulp.

Predicting the response of the dental pulp to SARS-CoV2 infection: a transcriptome-wide effect cross-analysis.

Pulpitis, inflammation of the dental pulp, is a disease that often necessitates emergency dental care. While pulpitis is considered to be a microbial disease primarily caused by bacteria, viruses have also been implicated in its pathogenesis. Here, we determined the expression of the SARS-CoV2 receptor, angiotensin converting enzyme 2 (ACE2) and its associated cellular serine protease TPMRSS2 in the dental pulp under normal and inflamed conditions. Next, we explored the relationship between the SARS-CoV-2/human interactome and genes expressed in pulpitis. Using existing datasets we show that both ACE2 and TPMRSS2 are expressed in the dental pulp and, that their expression does not change under conditions of inflammation. Furthermore, Master Regulator Analysis of the SARS-CoV2/human interactome identified 75 relevant genes whose expression values are either up-regulated or down-regulated in both the human interactome and pulpitis. Our results suggest that the dental pulp is vulnerable to SARS-CoV2 infection and that SARS-CoV-2 infection of the dental pulp may contribute to worse outcomes of pulpitis.