CXCR4 receptor expression

Number of papers to date have shown that the CXCR4 receptors expressed in both neuronal and glial cells are functional and coupled to multiple intracellular pathways (Lazarini et al. 2003). The CXCR4 through pertussis toxin (PTX)- sensitive G proteins is coupled to at least two distinct signaling pathways (1) the first pathway, involving the activation of phosphatidylinositol- 3 (PI-3) kinase and extracellular signal... 

Crane, U, Wallace, CA, McKillop-Smith, S, and Forrester, JV, 2000b. CXCR4 receptor expression on human retinal pigment epithelial cells from the blood-retina barrier leads to chemokine secretion and migration in response to stromal cell-derived factor 1 alpha. J Immunol 165,4372-4378. 

CaUebaut C, Jacotot E, Blanco J et al (1998) Increased rate of HIV-1 entry and its cytopathic effect in CD4+/CXCR4+ T cells expressing relatively high levels of CD26. Exp Cell Res 241 352-362 Campbell JJ, Qin S, Unutmaz D et al (2001) Unique subpopulations of CD56+ NK and NK-T peripheral blood lymphocytes identified by chemokine receptor expression repertoire. J Immunol 166 6477-6482... 

A further interesting phenotype identified in SDF-1/CXCR4 knockout mice is a deficiency in blood vessel development, initially observed in the gastrointestinal system (Tachibana et al. 1998). Consistent with such observations, CXCR4 receptors have been shown to be expressed by hemangioblasts, the earliest common precursor to hematopoietic and endothelial stem cells, found in yolk sac... 

Toth PT, Ren D, Miller RJ (2004) Regulation of CXCR4 receptor dimerization by the chemokine SDF-lalpha and the HIV-1 coat protein gpl20 a fluorescence resonance energy transfer (FRET) study. J Pharmacol Exp Ther 310 8-17 Tran PB, Miller RJ (2005) HIV-1, chemokines and neurogenesis. Neurotox Res 8 149-158 Tran PB, Ren D, Veldhouse TJ, Miller RJ (2004) Chemokine receptors are expressed widely by embryonic and adult neural progenitor cells. J Neurosci Res 76 20-34... 

Opioid regulation of chemokine and chemokine receptor expression has several disease- related implications. Viral infection by HIV-1 can be enhanced with opioids that activate MOR while the opposite can be true for opioids that activate KOR. Increased levels of HIV-1 coreceptors, such as CCR5 and CXCR4, can promote viral binding and trafficking of HIV-1 virally infected cells. It is likely that this allows the viral disease to progress in the immune cells of the blood in addition to neurological reservoirs. Alterations of chemokine receptor expression will not only affect viral infection, but also alter immune system function. In certain diseases... 

Nagase H, Kudo K, Izumi S, et al. Chemokine receptor expression profile of eosinophils at inflamed tissue sites decreased CCR3 and increased CXCR4 expression by lung eosinophils. J Allergy Clin Immunol 2001 108(4) 563-569. 

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