TY - JOUR
T1 - Stromal cell-derived factor 1 (CXCL12) induces monocyte migration into human synovium transplanted onto SCID mice
AU - Blades, M C
AU - Ingegnoli, F
AU - Wheller, S K
AU - Manzo, A
AU - Wahid, S
AU - Panayi, G S
AU - Perretti, M
AU - Pitzalis, C
PY - 2002
Y1 - 2002
N2 - Objective. The mechanisms by which monocyte/ macrophage cells migrate to the joint involve a series of integrated adhesion and signaling events in which chemokines and their receptors are strongly implicated. This study was undertaken to investigate the hypothesis that stromal cell-derived factor 1 (SDF-1), a CXC chemokine (CXCL12), plays a critical role in monocyte/ macrophage localization to synovium. Methods. SDF-1 and CXC receptor 4 (CXCR4) expression in rheumatoid arthritis (RA) and osteoarthritis synovium and graft SDF-1, tumor necrosis factor alpha (TNFalpha), and human and murine vascular markers were examined by immunohistochemistry and double-immunofluorescence. The functional capacity of SDF-1 to modulate monocyte migration into joints was investigated by examining the localization of promyelomonocytic U937 cells into synovial tissue transplanted into SCID mice. SDF-1, TNFalpha, or saline was injected into graft sites and response determined by the number of fluorescently labeled U937 cells (injected intravenously) detected in grafts by ultraviolet microscopy. Results. SDF-1 and CXCR4 were highly expressed in CD68+ cells in the RA synovium. SDF-1 induced U937 cell migration in vitro and in vivo in a dose-dependent manner and, in vivo, SDF-1 was more effective than TNFalpha. In contrast to TNFalpha, SDF-1 did not induce intracellular adhesion molecule I in transplant microvasculature. Furthermore, intragraft injection of SDF-1 did not up-regulate TNFalpha, or vice versa. Conclusion. This study demonstrates, for the first time, that SDF-1 is functional in vivo when injected into synovial grafts. In addition, SDF-1 is more potent than TNFalpha, and its mechanisms of action appear to be autonomous. Therefore, SDF-1 may be an important TNF-independent molecule involved in the migration to and retention of inflammatory effector cells in the joint.
AB - Objective. The mechanisms by which monocyte/ macrophage cells migrate to the joint involve a series of integrated adhesion and signaling events in which chemokines and their receptors are strongly implicated. This study was undertaken to investigate the hypothesis that stromal cell-derived factor 1 (SDF-1), a CXC chemokine (CXCL12), plays a critical role in monocyte/ macrophage localization to synovium. Methods. SDF-1 and CXC receptor 4 (CXCR4) expression in rheumatoid arthritis (RA) and osteoarthritis synovium and graft SDF-1, tumor necrosis factor alpha (TNFalpha), and human and murine vascular markers were examined by immunohistochemistry and double-immunofluorescence. The functional capacity of SDF-1 to modulate monocyte migration into joints was investigated by examining the localization of promyelomonocytic U937 cells into synovial tissue transplanted into SCID mice. SDF-1, TNFalpha, or saline was injected into graft sites and response determined by the number of fluorescently labeled U937 cells (injected intravenously) detected in grafts by ultraviolet microscopy. Results. SDF-1 and CXCR4 were highly expressed in CD68+ cells in the RA synovium. SDF-1 induced U937 cell migration in vitro and in vivo in a dose-dependent manner and, in vivo, SDF-1 was more effective than TNFalpha. In contrast to TNFalpha, SDF-1 did not induce intracellular adhesion molecule I in transplant microvasculature. Furthermore, intragraft injection of SDF-1 did not up-regulate TNFalpha, or vice versa. Conclusion. This study demonstrates, for the first time, that SDF-1 is functional in vivo when injected into synovial grafts. In addition, SDF-1 is more potent than TNFalpha, and its mechanisms of action appear to be autonomous. Therefore, SDF-1 may be an important TNF-independent molecule involved in the migration to and retention of inflammatory effector cells in the joint.
UR - http://www.scopus.com/inward/record.url?scp=0036185087&partnerID=8YFLogxK
U2 - 10.1002/art.10102
DO - 10.1002/art.10102
M3 - Article
SN - 1529-0131
VL - 46
SP - 824
EP - 836
JO - Arthritis & Rheumatism
JF - Arthritis & Rheumatism
IS - 3
ER -