NLRP12 negatively modulates inducible nitric oxide synthase (iNOS) expression and tumor necrosis factor-α production in Porphyromonas gingivalis LPS-treated mouse macrophage cell line (RAW264.7)

Objective The aim of the present study is to investigate the participation of NLRP12 in Porphyromonas gingivalis LPS-activated mouse macrophages. Methods NLRP12-depleted mouse macrophages were stimulated with P. gingivalis LPS (1 μg/ml.). At indicated time points, the treated cells were lysed and the supernatant from treated cells was collected. Gene and protein expression of NLRP12 and iNOS were determined by RT-PCR and immunoblotting, respectively. The level of TNF-α production in the supernatant of the activated cells was determined by ELISA. Results and conclusion NLRP12 was upregulated in response to stimulation with P. gingivalis LPS. In addition, when NLRP12 was depleted in P. gingivalis LPS-treated macrophages, an increase in TNF-α production and iNOS expression were observed when compared to those of the control cells, indicating that NLRP12 downregulates the inflammatory cytokine and antimicrobial molecule production in the macrophages.