Ola Grimsholm1, Yongzhi Guo, Tor Ny, Sture Forsgren. 1. Department of Integrative Medical Biology, Section for Anatomy, Umeå University, Umeå, Sweden. ola.grimsholm@anatomy.umu.se
Abstract
BACKGROUND: It is likely that neurotrophins (NTs) are of great importance for the articular cartilage and the inflammation process in arthritis. METHODS: The immunohistochemical expression of the NTs nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) and the associated receptors p75, TrkA and TrkB was examined in the knee joint of arthritic and healthy mice. RESULTS: Immunoreactions for NGF and BDNF were detected in cells and nerve fiber varicosities in the inflammatory infiltrates of the synovial tissue of arthritic joints but not in synovial tissue of controls. p75-immunoreactive nerve fiber-like strands were detected in inflammatory infiltrates. Immunostaining for NGF, BDNF, p75, TrkA and TrkB was noted in articular chondrocytes. There was a statistically significant decrease in reactions for NGF (p < 0.001), TrkA (p = 0.001) and p75 (p < 0.001) in articular chondrocytes in joints exhibiting severe arthritis. CONCLUSION: The findings show that an NT system develops in inflammatory infiltrates of the synovial tissue. Furthermore, most interestingly, autocrine/paracrine effects appear to exist concerning NTs for the articular chondrocytes. The downregulated expression of NGF and NT receptors in articular chondrocytes in arthritis is a new aspect concerning the involvement of NTs in cartilage. Copyright 2008 S. Karger AG, Basel.
BACKGROUND: It is likely that neurotrophins (NTs) are of great importance for the articular cartilage and the inflammation process in arthritis. METHODS: The immunohistochemical expression of the NTs nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) and the associated receptors p75, TrkA and TrkB was examined in the knee joint of arthritic and healthy mice. RESULTS: Immunoreactions for NGF and BDNF were detected in cells and nerve fiber varicosities in the inflammatory infiltrates of the synovial tissue of arthritic joints but not in synovial tissue of controls. p75-immunoreactive nerve fiber-like strands were detected in inflammatory infiltrates. Immunostaining for NGF, BDNF, p75, TrkA and TrkB was noted in articular chondrocytes. There was a statistically significant decrease in reactions for NGF (p < 0.001), TrkA (p = 0.001) and p75 (p < 0.001) in articular chondrocytes in joints exhibiting severe arthritis. CONCLUSION: The findings show that an NT system develops in inflammatory infiltrates of the synovial tissue. Furthermore, most interestingly, autocrine/paracrine effects appear to exist concerning NTs for the articular chondrocytes. The downregulated expression of NGF and NT receptors in articular chondrocytes in arthritis is a new aspect concerning the involvement of NTs in cartilage. Copyright 2008 S. Karger AG, Basel.
Authors: Christian Barthel; Nataliya Yeremenko; Roland Jacobs; Reinhold E Schmidt; Michael Bernateck; Henning Zeidler; Paul-Peter Tak; Dominique Baeten; Markus Rihl Journal: Arthritis Res Ther Date: 2009-06-02 Impact factor: 5.156
Authors: Serge A van de Pavert; Brenda J Olivier; Gera Goverse; Mark F Vondenhoff; Mascha Greuter; Patrick Beke; Kim Kusser; Uta E Höpken; Martin Lipp; Karen Niederreither; Rune Blomhoff; Kasia Sitnik; William W Agace; Troy D Randall; Wouter J de Jonge; Reina E Mebius Journal: Nat Immunol Date: 2009-09-27 Impact factor: 25.606