The Journal of Neuroscience, July 15, 2001, 21(14):5027-5035
Chemokines and Glycoprotein120 Produce Pain Hypersensitivity by
Directly Exciting Primary Nociceptive Neurons
Seog Bae
Oh1,
Phuong B.
Tran1,
Samantha E.
Gillard1,
Robert W.
Hurley2,
Donna L.
Hammond2, and
Richard J.
Miller1
1 Department of Neurobiology, Pharmacology, and
Physiology, and 2 Department of Anesthesia and Critical
Care and The Committee on Neurobiology, University of Chicago, Chicago,
Illinois 60637
Human immunodeficiency virus-1 (HIV-1) infection is associated with
numerous effects on the nervous system, including pain and peripheral
neuropathies. We now demonstrate that cultured rat dorsal root ganglion
(DRG) neurons express a wide variety of chemokine receptors, including
those that are thought to act as receptors for the HIV-1 coat protein
glycoprotein120 (gp120). Chemokines that activate all of the known
chemokine receptors increased [Ca2+]i
in subsets of cultured DRG cells. Many neurons responded to multiple
chemokines and also to bradykinin, ATP, and capsaicin. Immunohistochemical studies demonstrated the expression of the CXCR4
and CCR4 chemokine receptors on populations of DRG neurons that also
expressed substance P and the VR1 vanilloid receptor. RT-PCR analysis
confirmed the expression of CXCR4, CX3CR1, CCR4, and CCR5 mRNAs in DRG
neurons. Chemokines and gp120 produced excitatory effects on DRG
neurons and also stimulated the release of substance P. Chemokines and
gp120 also produced allodynia after injection into the rat paw. Thus
these results provide evidence that chemokines and gp120 may produce
painful effects via direct actions on chemokine receptors expressed by
nociceptive neurons. Chemokine receptor antagonists may be important
therapeutic interventions in the pain that is associated with HIV-1
infection and inflammation.
Key words:
neuropathies; AIDS; pain; dorsal root ganglia; G-protein-coupled receptor; substance P
Copyright © 2001 Society for Neuroscience 0270-6474/01/21145027-09$05.00/0