Perturbation of chemokine networks by gene deletion alters the reinforcing actions of ethanol.
Microarray analysis of human alcoholic brain and cultured cells exposed to ethanol showed significant changes in expression of genes related to immune or inflammatory responses, including chemokines and chemokine receptors. To test the hypothesis that chemokines exhibit previously undiscovered pleiotropic effects important for the behavioral actions of ethanol, we studied mutant mice with deletion of the Ccr2, Ccr5, Ccl2 or Ccl3 genes. Deletion of Ccr2, Ccl2 (females) or Ccl3 in mice resulted in lower preference for alcohol and consumption of lower amounts of alcohol in a two-bottle choice test as compared with wild-type mice. Ethanol treatment (2.5 g/kg, i.p.) induced stronger conditioned taste aversion in Ccr2, Ccl2 or Ccl3 null mutant mice than in controls. Ccr2 and Ccr5 null mutant mice did not differ from wild-type mice in ethanol-induced loss of righting reflex (LORR), but mice lacking Ccl2 or Ccl3 showed longer LORR than wild-type mice. There were no differences between mutant strains and wild-type mice in severity of ethanol-induced withdrawal. Genetic mapping of chromosome 11 for the Ccl2 and Ccl3 genes (46.5 and 47.6 cM, respectively) revealed that an alcohol-induced LORR QTL region was contained within the introgressed region derived from 129/SvJ, which may cause some behavioral phenotypes observed in the null mice. On the contrary, known QTLs on Chr 9 are outside of 129/SvJ region in Ccr2 and Ccr5 (71.9 and 72.0 cM, respectively) null mutant mice. These data show that disruption of the chemokine network interferes with motivational effects of alcohol.
Blednov
Yuri A
YA
Waggoner Center for Alcohol and Addiction Research, University of Texas A 4800, 1 University Station, 2500 Speedway MBB 1.124, Austin, TX 78712-1095, USA. yablednov@mail.utexas.edu
Bergeson
Susan E
SE
Walker
Danielle
D
Ferreira
Vania M M
VM
Kuziel
William A
WA
Harris
R Adron
RA
D000428:Alcohol Drinking / Q000235:genetics* / Q000276:immunology; D000437:Alcoholism / Q000235:genetics / Q000276:immunology; D000818:Animals; D001245:Association Learning / Q000502:physiology; D018932:Chemokine CCL2 / Q000172:deficiency / Q000235:genetics*; D054405:Chemokine CCL3; D054407:Chemokine CCL4; D019742:Chemokines, CC / Q000172:deficiency / Q000235:genetics*; D003214:Conditioning, Classical / Q000502:physiology*; D004195:Disease Models, Animal; D000431:Ethanol; D005260:Female; D017353:Gene Deletion; D019402:Macrophage Inflammatory Proteins / Q000172:deficiency / Q000235:genetics*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D054390:Receptors, CCR2; D019713:Receptors, CCR5 / Q000172:deficiency / Q000235:genetics; D019707:Receptors, Chemokine / Q000172:deficiency / Q000235:genetics; D012054:Reinforcement, Psychology; D012720:Severity of Illness Index; D012737:Sex Factors; D015398:Signal Transduction / Q000235:genetics; D013375:Substance Withdrawal Syndrome / Q000235:genetics / Q000276:immunology; D013649:Taste / Q000235:genetics
C515334:CCR2 protein, human; C496534:Ccl3 protein, mouse; C515335:Ccr2 protein, mouse; D018932:Chemokine CCL2; D054405:Chemokine CCL3; D054407:Chemokine CCL4; D019742:Chemokines, CC; D019402:Macrophage Inflammatory Proteins; D054390:Receptors, CCR2; D019713:Receptors, CCR5; D019707:Receptors, Chemokine; D000431:Ethanol