Constitutive chemokines

Structural criteria originally led to the classification of the nearly 50 known chemokines in four families, C, CC, CXC, and CX3C. Today scientists refer to them as constitutive chemokines, which are usually regulated during development, and as inducible chemokines, whose expression is regulated mainly during inflammatory processes. 

Inflanunatory chemokines have also been described as inducible chemokines, whereas homeostatic chemokines are also known as lymphoid or constitutive chemokines. 

FIGURE 3.12 Dependence of constitutive receptor activity as ordinates (expressed as a percent of the maximal response to a full agonist for each receptor) versus magnitude of receptor expression (expressed as the amount of human cDNA used for transient transfection, logarithmic scale) in Xenopus laevis melanophores. Data shown for human chemokine CCR5 receptors (open circles), chemokine CXCR receptors (filled triangles), neuropeptide Y type 1 receptors (filled diamonds), neuropeptide Y type 2 receptors (open squares), and neuropeptide Y type 4 receptors (open inverted triangles). Data recalculated and redrawn from [27],... 

An emerging area of interest for the physiological action of the brain of chanokine is the intercellular communication system between neuronal and ghal cells. Indeed, recent in vitro and in situ studies indicated that the chemokines together with then-receptors are constitutively expressed by glial cells and neurons in mature brain (Asensio and Campbell 1999 Cho and Miller 2002 Tran and Miller 2003 Rostene... 

The opioid and the chemokine systems constitute two vital signaling networks in the brain and periphery and a brief background on these individual pathways in the CNS would help appreciate the relevance of their cross-talk in normal as well as diseased brain. 

Galliera E, Jala VR, Trent JO, et al. beta-Arrestin-dependent constitutive internalization of the human chemokine decoy receptor D6. J Biol Chem 2004 279(24) 25590-25597. 

Borzi RM, Mazzetti I, Macor S, et al. Flow cytometric analysis of intracellular chemokines in chondrocytes in vivo constitutive expression and enhancement in osteoarthritis and rheumatoid arthritis. FEBS Lett 1999 455(3) 238-242. 

Luan J, Shattuck-Brandt R, Haghnegahdar H, et al. Mechanism and biological significance of constitutive expression of MGSA/GRO chemokines in malignant melanoma tumor progression. J Leukoc Biol 1997 62(5) 588-597. 

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