Fractalkine: a novel angiogenic chemokine in rheumatoid arthritis.
Angiogenesis is an important aspect of the vasculoproliferation found in the rheumatoid arthritic (RA) pannus. We have previously implicated members of the CXC chemokine family as potent angiogenic mediators in RA. We investigated the possibility that the sole member of the CX(3)C chemokine family, fractalkine (fkn), induces angiogenesis and that fkn might mediate angiogenesis in RA. Recombinant human fkn significantly induced migration of human dermal microvascular endothelial cells (HMVECs), a facet of the angiogenic response, in the pmol/L range in a concentration-dependent manner (P < 0.05). Fkn also induced the formation of significantly more endothelial tubes on Matrigel than did a negative control (P < 0.05). Fkn significantly induced 2.3-fold more blood vessel growth than control in the in vivo Matrigel plug assays (P < 0.05). We identified HMVEC expression of the fkn receptor, CX(3)CR1. Next, we determined if RA synovial fluid (SF)-induced angiogenesis was fkn-dependent. SFs from six RA patients immunodepleted of soluble fkn induced 56% less migration of HMVECs than did sham-depleted RA SFs (P < 0.05). In vivo, immunodepletion of fkn from six RA SFs significantly inhibited their angiogenic activity in Matrigel plug assays (P < 0.05). Immunodepletion of fkn from five RA synovial tissue homogenates inhibited their ability to induce angiogenesis in in vivo Matrigel plug assays (P < 0.05). These results establish a new function for fkn as an angiogenic mediator and suggest that it may mediate angiogenesis in RA.
Volin
M V
MV
Department of Medicine, Northwestern University, Chicago, Illinois, USA.
Woods
J M
JM
Amin
M A
MA
Connors
M A
MA
Harlow
L A
LA
Koch
A E
AE
D001172:Arthritis, Rheumatoid / Q000150:complications* / Q000503:physiopathology*; D000073883:CX3C Chemokine Receptor 1; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D054428:Chemokine CX3CL1; D020523:Chemokines, CX3C / Q000494:pharmacology / Q000502:physiology*; D002630:Chemotactic Factors / Q000378:metabolism; D002633:Chemotaxis / Q000502:physiology; D003094:Collagen / Q000494:pharmacology; D004338:Drug Combinations; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects / Q000502:physiology; D006801:Humans; D007797:Laminin / Q000494:pharmacology; D008565:Membrane Proteins / Q000494:pharmacology / Q000502:physiology*; D008833:Microcirculation; D009389:Neovascularization, Pathologic / Q000209:etiology* / Q000473:pathology; D011509:Proteoglycans / Q000494:pharmacology; D018121:Receptors, Cytokine / Q000378:metabolism; D015728:Receptors, HIV / Q000378:metabolism; D012867:Skin / Q000098:blood supply; D013582:Synovial Fluid / Q000187:drug effects / Q000378:metabolism / Q000502:physiology; D013583:Synovial Membrane / Q000503:physiopathology
D000073883:CX3C Chemokine Receptor 1; C515538:CX3CL1 protein, human; D054428:Chemokine CX3CL1; D020523:Chemokines, CX3C; D002630:Chemotactic Factors; D004338:Drug Combinations; D007797:Laminin; D008565:Membrane Proteins; D011509:Proteoglycans; D018121:Receptors, Cytokine; D015728:Receptors, HIV; C059485:matrigel; D003094:Collagen