Porphyromonas gingivalis infection of oral keratinocytes drives the release of pro-inflammatory extracellular vesicles

Abstract

Periodontitis is an inflammatory disease caused by bacterial infection. Recent studies have identified extracellular vesicles (EVs) as potential mediators of inflammation. This study aimed to evaluate the pro-inflammatory properties and miRNA content of EVs secreted in response to Porphyromonas gingivalis infection. Oral epithelial cells (ECs) were infected with P. gingivalis (MOI 100) for 24 h. EVs from infected (P.g.-ECs-EVs) and uninfected cells (ECs-EVs) were isolated, characterized, and tested on naive ECs. Cellular activity, inflammatory markers (TNF-α, IL-1β), and miRNA content of the secreted EVs were evaluated. Bioinformatic analysis was subsequently performed to identify potential targets of differentially expressed miRNAs. P. gingivalis infection increased EV production by 102-fold. P.g.-ECs-EVs exhibited distinct properties compared to ECs-EVs, including higher metabolic activity and elevated TNF-α and IL-1β expression and secretion levels in exposed ECs. Several inflammation-related miRNAs were highly upregulated in P.g.-ECs-EVs (11- to 142-fold; p < 0.001). P. gingivalis promotes the secretion of pro-inflammatory EVs by ECs, suggesting their role as key mediators in P. gingivalis-induced inflammation and periodontal tissue destruction.