TY - JOUR
T1 - Transthyretin deposition in articular cartilage
T2 - A novel mechanism in the pathogenesis of osteoarthritis
AU - Akasaki, Yukio
AU - Reixach, Natàlia
AU - Matsuzaki, Tokio
AU - Alvarez-Garcia, Oscar
AU - Olmer, Merissa
AU - Iwamoto, Yukihide
AU - Buxbaum, Joel N.
AU - Lotz, Martin K.
N1 - Publisher Copyright:
© 2015, American College of Rheumatology.
PY - 2015/8/1
Y1 - 2015/8/1
N2 - Objective Amyloid deposits are prevalent in osteoarthritic (OA) joints. We undertook this study to define the dominant precursor and to determine whether the deposits affect chondrocyte functions. Methods Amyloid deposition in human normal and OA knee cartilage was determined by Congo red staining. Transthyretin (TTR) in cartilage and synovial fluid was analyzed by immunohistochemistry and Western blotting. The effects of recombinant amyloidogenic and nonamyloidogenic TTR variants were tested in human chondrocyte cultures. Results Normal cartilage from young donors did not contain detectable amyloid deposits, but 7 of 12 aged normal cartilage samples (58%) and 12 of 12 OA cartilage samples (100%) had Congo red staining with green birefringence under polarized light. TTR, which is located predominantly at the cartilage surfaces, was detected in all OA cartilage samples and in a majority of aged normal cartilage samples, but not in normal cartilage samples from young donors. Chondrocytes and synoviocytes did not contain significant amounts of TTR messenger RNA. Synovial fluid TTR levels were similar in normal and OA knees. In cultured chondrocytes, only an amyloidogenic TTR variant induced cell death as well as the expression of proinflammatory cytokines and extracellular matrix-degrading enzymes. The effects of amyloidogenic TTR on gene expression were mediated in part by Toll-like receptor 4, receptor for advanced glycation end products, and p38 MAPK. TTR-induced cytotoxicity was inhibited by resveratrol, a plant polyphenol that stabilizes the native tetrameric structure of TTR. Conclusion These findings are the first to suggest that TTR amyloid deposition contributes to cell and extracellular matrix damage in articular cartilage in human OA and that therapies designed to reduce TTR amyloid formation might be useful.
AB - Objective Amyloid deposits are prevalent in osteoarthritic (OA) joints. We undertook this study to define the dominant precursor and to determine whether the deposits affect chondrocyte functions. Methods Amyloid deposition in human normal and OA knee cartilage was determined by Congo red staining. Transthyretin (TTR) in cartilage and synovial fluid was analyzed by immunohistochemistry and Western blotting. The effects of recombinant amyloidogenic and nonamyloidogenic TTR variants were tested in human chondrocyte cultures. Results Normal cartilage from young donors did not contain detectable amyloid deposits, but 7 of 12 aged normal cartilage samples (58%) and 12 of 12 OA cartilage samples (100%) had Congo red staining with green birefringence under polarized light. TTR, which is located predominantly at the cartilage surfaces, was detected in all OA cartilage samples and in a majority of aged normal cartilage samples, but not in normal cartilage samples from young donors. Chondrocytes and synoviocytes did not contain significant amounts of TTR messenger RNA. Synovial fluid TTR levels were similar in normal and OA knees. In cultured chondrocytes, only an amyloidogenic TTR variant induced cell death as well as the expression of proinflammatory cytokines and extracellular matrix-degrading enzymes. The effects of amyloidogenic TTR on gene expression were mediated in part by Toll-like receptor 4, receptor for advanced glycation end products, and p38 MAPK. TTR-induced cytotoxicity was inhibited by resveratrol, a plant polyphenol that stabilizes the native tetrameric structure of TTR. Conclusion These findings are the first to suggest that TTR amyloid deposition contributes to cell and extracellular matrix damage in articular cartilage in human OA and that therapies designed to reduce TTR amyloid formation might be useful.
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U2 - 10.1002/art.39178
DO - 10.1002/art.39178
M3 - Article
C2 - 25940564
AN - SCOPUS:84938151998
VL - 67
SP - 2097
EP - 2107
JO - Arthritis and Rheumatology
JF - Arthritis and Rheumatology
SN - 2326-5191
IS - 8
ER -