BACKGROUND AND OBJECTIVE: The liver plays a major role in clearing systemic bacterial infections. In addition, inflammatory cytokines produced in the liver play a critical role in systemic cytokine levels. The aim of this study was to investigate the production of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) by hepatocytes in response to periodontal pathogens. MATERIAL AND METHODS: The mouse hepatic carcinoma cell line Hepa-1.6 and the mouse macrophage-like cell line RAW 264 were co-cultured in Transwell insert plates. Cells were stimulated with bacterial extracts prepared from Porphyromonas gingivalis and the induction of TNF-α and IL-6 was measured using real-time PCR and ELISA. RESULTS: After stimulation with bacteria, the induction of TNF-α and IL-6 was observed in RAW 264 cells and Hepa-1.6 cells. Significant reduction of TNF-α mRNA expression in Hepa-1.6 cells was observed after treatment with antibody to TNF-α. CONCLUSION: The results obtained in the present study show that P. gingivalis extract induces TNF-α and IL-6 in an in vitro liver model and that macrophage-derived TNF-α mediates the induction of TNF-α in hepatocytes.
BACKGROUND AND OBJECTIVE: The liver plays a major role in clearing systemic bacterial infections. In addition, inflammatory cytokines produced in the liver play a critical role in systemic cytokine levels. The aim of this study was to investigate the production of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) by hepatocytes in response to periodontal pathogens. MATERIAL AND METHODS: The mousehepatic carcinoma cell line Hepa-1.6 and the mouse macrophage-like cell line RAW 264 were co-cultured in Transwell insert plates. Cells were stimulated with bacterial extracts prepared from Porphyromonas gingivalis and the induction of TNF-α and IL-6 was measured using real-time PCR and ELISA. RESULTS: After stimulation with bacteria, the induction of TNF-α and IL-6 was observed in RAW 264 cells and Hepa-1.6 cells. Significant reduction of TNF-α mRNA expression in Hepa-1.6 cells was observed after treatment with antibody to TNF-α. CONCLUSION: The results obtained in the present study show that P. gingivalis extract induces TNF-α and IL-6 in an in vitro liver model and that macrophage-derived TNF-α mediates the induction of TNF-α in hepatocytes.
Authors: Elizabeth C Stahl; Evan R Delgado; Frances Alencastro; Samuel T LoPresti; Patrick D Wilkinson; Nairita Roy; Martin J Haschak; Clint D Skillen; Satdarshan P Monga; Andrew W Duncan; Bryan N Brown Journal: Am J Pathol Date: 2019-12-13 Impact factor: 4.307