TY - JOUR
T1 - Involvement of sensory nerves and immune cells in osteophyte formation in the ankle joint of adjuvant arthritic rats
AU - Wu, Zhou
AU - Nagata, Kengo
AU - Iijima, Tadahiko
N1 - Funding Information:
Acknowledgements We would like to thank Dr. T. Kukita of our department for the valuable advice during this investigation. This study was supported by a Grant-in Aid for Scientific Research from the Ministry of Education, Science and Culture of Japan (number 14571737).
PY - 2002
Y1 - 2002
N2 - To study the mechanism of osteophyte formation in the ankle joints of adjuvant arthritic (AA) rats, the localization of peripheral nerves and immune cells in the synovia were investigated in both axotomized AA rats, whose sciatic nerves were resected before adjuvant injection, and sham-operated ones, using immunohistochemistry for low-affinity nerve growth factor receptor (p75NGFR), growth-associated protein (GAP)-43, calcitonin gene-related peptide (CGRP), helper T cell (W3/25), monocyte/macrophage (ED1), and transforming growth factor (TGF)-β1 and its receptor, TGF-βRII. In sham-operated AA rats, dense plexuses of CGRP-positive fibers were observed in the inflamed synovia close to the osteophytes. Most of the CGRP-positive fibers were also positive for p75NGFR and GAP-43. These fibers appeared to be newly sprouted sensory nerves. In axotomized AA rats, the synovia were supplied with no CGRP-positive fibers and the sizes of the osteophytes were smaller than those in sham-operated animals. The ratio of the number of both W3/25- and ED1-positive cells in the inflamed synovia of sham-operated rats peaked at weeks 2-3 after adjuvant injection. The peak, however, lasted until week 4 in axotomized ones. In both animal groups, the macrophages and the osteoblasts were stained for TGF-β1. The osteoblasts covering the osteophytes were also stained for TGF-βRII. The present findings suggest that the sensory nerves and the macrophages may be involved in osteophyte formation in the ankle joints of AA rats.
AB - To study the mechanism of osteophyte formation in the ankle joints of adjuvant arthritic (AA) rats, the localization of peripheral nerves and immune cells in the synovia were investigated in both axotomized AA rats, whose sciatic nerves were resected before adjuvant injection, and sham-operated ones, using immunohistochemistry for low-affinity nerve growth factor receptor (p75NGFR), growth-associated protein (GAP)-43, calcitonin gene-related peptide (CGRP), helper T cell (W3/25), monocyte/macrophage (ED1), and transforming growth factor (TGF)-β1 and its receptor, TGF-βRII. In sham-operated AA rats, dense plexuses of CGRP-positive fibers were observed in the inflamed synovia close to the osteophytes. Most of the CGRP-positive fibers were also positive for p75NGFR and GAP-43. These fibers appeared to be newly sprouted sensory nerves. In axotomized AA rats, the synovia were supplied with no CGRP-positive fibers and the sizes of the osteophytes were smaller than those in sham-operated animals. The ratio of the number of both W3/25- and ED1-positive cells in the inflamed synovia of sham-operated rats peaked at weeks 2-3 after adjuvant injection. The peak, however, lasted until week 4 in axotomized ones. In both animal groups, the macrophages and the osteoblasts were stained for TGF-β1. The osteoblasts covering the osteophytes were also stained for TGF-βRII. The present findings suggest that the sensory nerves and the macrophages may be involved in osteophyte formation in the ankle joints of AA rats.
UR - http://www.scopus.com/inward/record.url?scp=0036381610&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0036381610&partnerID=8YFLogxK
U2 - 10.1007/s00418-002-0443-x
DO - 10.1007/s00418-002-0443-x
M3 - Article
C2 - 12271357
AN - SCOPUS:0036381610
SN - 0948-6143
VL - 118
SP - 213
EP - 220
JO - Histochemistry and Cell Biology
JF - Histochemistry and Cell Biology
IS - 3
ER -