OBJECTIVE: To evaluate the involvement of the chemokine/chemokine receptor system in cartilage degradation in osteoarthritis (OA). METHODS: Expression of the 4 C-C chemokines monocyte chemoattractant protein 1 (MCP-1), macrophage inflammatory protein 1alpha (MIP-1alpha), MIP-1beta, and RANTES, and their receptors CCR-2 and CCR-5, was assessed in 11 OA patients and 5 normal controls, by reverse transcriptase-polymerase chain reaction (RT-PCR), enzyme-linked immunosorbent assay (ELISA), immunochemistry, and flow cytometry on untreated or interleukin-1beta (IL-1beta)- and/or tumor necrosis factor alpha (TNFalpha)-stimulated chondrocytes. The effects of these chemokines on the expression of matrix metalloproteinases (MMP) and tissue inhibitor of metalloproteinases were assayed by RT-PCR and ELISA. The effects on proteoglycan synthesis and release were also assayed, using 35S-sulfate incorporation and 35S-proteoglycan release. RESULTS: The C-C chemokines and their receptors CCR-2 and CCR-5 were found to be expressed in normal and OA chondrocytes. However, regulation of chemokine expression by IL-1beta and TNFalpha differed between normal and OA chondrocytes. Intracellular staining revealed that approximately 20% of the chondrocytes contained CCR-2 and CCR-5 in the cytoplasm, whereas cell surface expression was detected less frequently. Interestingly, RANTES induced expression of its own receptor, CCR-5, suggesting an autocrine/paracrine pathway of the chemokine within the cartilage milieu. Finally, addition of MCP-1 or RANTES not only induced MMP-3 expression, but also inhibited proteoglycan synthesis and enhanced proteoglycan release from the chondrocytes. CONCLUSION: The differential expression of chemokines and their receptors under the regulation of IL-1beta and TNFalpha suggests that the cytokine-triggered chemokine system may play a key role in the cartilage degradation of OA, possibly acting in an autocrine/paracrine manner.
OBJECTIVE: To evaluate the involvement of the chemokine/chemokine receptor system in cartilage degradation in osteoarthritis (OA). METHODS: Expression of the 4 C-C chemokines monocyte chemoattractant protein 1 (MCP-1), macrophage inflammatory protein 1alpha (MIP-1alpha), MIP-1beta, and RANTES, and their receptors CCR-2 and CCR-5, was assessed in 11 OA patients and 5 normal controls, by reverse transcriptase-polymerase chain reaction (RT-PCR), enzyme-linked immunosorbent assay (ELISA), immunochemistry, and flow cytometry on untreated or interleukin-1beta (IL-1beta)- and/or tumor necrosis factor alpha (TNFalpha)-stimulated chondrocytes. The effects of these chemokines on the expression of matrix metalloproteinases (MMP) and tissue inhibitor of metalloproteinases were assayed by RT-PCR and ELISA. The effects on proteoglycan synthesis and release were also assayed, using 35S-sulfate incorporation and 35S-proteoglycan release. RESULTS: The C-C chemokines and their receptors CCR-2 and CCR-5 were found to be expressed in normal and OA chondrocytes. However, regulation of chemokine expression by IL-1beta and TNFalpha differed between normal and OA chondrocytes. Intracellular staining revealed that approximately 20% of the chondrocytes contained CCR-2 and CCR-5 in the cytoplasm, whereas cell surface expression was detected less frequently. Interestingly, RANTES induced expression of its own receptor, CCR-5, suggesting an autocrine/paracrine pathway of the chemokine within the cartilage milieu. Finally, addition of MCP-1 or RANTES not only induced MMP-3 expression, but also inhibited proteoglycan synthesis and enhanced proteoglycan release from the chondrocytes. CONCLUSION: The differential expression of chemokines and their receptors under the regulation of IL-1beta and TNFalpha suggests that the cytokine-triggered chemokine system may play a key role in the cartilage degradation of OA, possibly acting in an autocrine/paracrine manner.
Authors: L Longobardi; J M Jordan; X A Shi; J B Renner; T A Schwartz; A E Nelson; D A Barrow; V B Kraus; A Spagnoli Journal: Osteoarthritis Cartilage Date: 2018-05-01 Impact factor: 6.576
Authors: Amy M Silverstein; Aaron M Stoker; Gerard A Ateshian; J Chloe Bulinski; James L Cook; Clark T Hung Journal: J Orthop Res Date: 2016-05-29 Impact factor: 3.494