Research progress on the regulation of periodontal innate immune cells by caspases

Periodontitis is a chronic inflammatory disease, and its occurrence and development are closely related to the imbalance of local innate immune responses. The caspase family plays a crucial role in regulating inflammatory responses and cell death pathways in periodontal innate immune cells (such as gingival epithelial cells, neutrophils, macrophages, dendritic cells, and natural killer cells). These proteases exhibit a dual regulatory effect on cellular functions. On one hand, apoptotic pathways mediated by caspase-3/7/9 enable the programmed clearance of senescent or damaged cells, while pyroptosis pathways mediated by caspase-1/4 contribute to immune defense and pathogen elimination, collectively helping to maintain tissue homeostasis. On the other hand, excessive activation of the caspase-1/gasdermin D pathway, as well as inflammatory amplification pathways involving caspase-4/6/8, promotes the release of inflammatory cytokines such as IL-1β and IL-18, leading to the disruption of the epithelial barrier and exacerbation of periodontal tissue damage. Caspase regulation exhibits both commonality and cell specificity. In gingival epithelial cells, caspase-1 mediates pyroptosis and inflammation activation, caspase-3 regulates apoptosis and proliferation signaling, and caspase-4 participates in differentiation regulation and pathogen-selective immune responses, collectively adapting to physiological and pathological changes. Neutrophils can utilize the caspase-1/gasdermin D signaling pathway to drive the release of neutrophil extracellular traps without triggering typical pyroptosis. In macrophages, caspase-1 and caspase-8 synergistically promote polarization toward the M1 phenotype, while caspase-3 acts as an apoptosis executor to facilitate macrophage transition to the M2 phenotype in specific microenvironments. This article reviews caspase’s specific mechanism of action in periodontal innate immune-related cells, aiming to provide a new theoretical basis for targeted regulation of caspase in the treatment of periodontitis.