1. Basic calcium phosphate crystals induce monocyte/macrophage IL-1β secretion through the NLRP3 inflammasome in vitro.
- Author
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Pazár B, Ea HK, Narayan S, Kolly L, Bagnoud N, Chobaz V, Roger T, Lioté F, So A, and Busso N
- Subjects
- Animals, Bone Marrow Cells immunology, Bone Marrow Cells metabolism, Bone Marrow Cells pathology, Calcium Pyrophosphate pharmacology, Caspase 1 deficiency, Caspase 1 physiology, Cell Line, Tumor, Cells, Cultured, Crystallization, Humans, Inflammasomes metabolism, Macrophages metabolism, Macrophages pathology, Mice, Mice, Inbred C57BL, Mice, Knockout, Monocytes metabolism, Monocytes pathology, NLR Family, Pyrin Domain-Containing 3 Protein, Uric Acid pharmacology, Calcium Phosphates pharmacology, Carrier Proteins physiology, Inflammasomes physiology, Interleukin-1beta metabolism, Macrophages immunology, Monocytes immunology
- Abstract
Basic calcium phosphate (BCP) crystals are associated with severe osteoarthritis and acute periarticular inflammation. Three main forms of BCP crystals have been identified from pathological tissues: octacalcium phosphate, carbonate-substituted apatite, and hydroxyapatite. We investigated the proinflammatory effects of these BCP crystals in vitro with special regard to the involvement of the NLRP3-inflammasome in THP-1 cells, primary human monocytes and macrophages, and mouse bone marrow-derived macrophages (BMDM). THP-1 cells stimulated with BCP crystals produced IL-1β in a dose-dependent manner. Similarly, primary human cells and BMDM from wild-type mice also produced high concentrations of IL-1β after crystal stimulation. THP-1 cells transfected with short hairpin RNA against the components of the NLRP3 inflammasome and mouse BMDM from mice deficient for NLRP3, apoptosis-associated speck-like protein, or caspase-1 did not produce IL-1β after BCP crystal stimulation. BCP crystals induced macrophage apoptosis/necrosis as demonstrated by MTT and flow cytometric analysis. Collectively, these results demonstrate that BCP crystals induce IL-1β secretion through activating the NLRP3 inflammasome. Furthermore, we speculate that IL-1 blockade could be a novel strategy to inhibit BCP-induced inflammation in human disease.
- Published
- 2011
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