title: The role of CCR1 expression in the retinal degeneration in rd mice.
abstract: OBJECTIVE
  Chemokine receptors are reported to be involved in neuronal cell death and CNS neurodegenerative diseases. The aim of the current study was to investigate the expression of CCR1, a major chemokine receptor for CC chemokines in retinal dystrophy in rd (retinal degeneration) mice and further explore its role in photoreceptor degeneration.
  
  
  METHODS
  The expression levels of CCR1 mRNA in the whole control and rd retinas at postnatal days (P) 8, 10, 12, 14, 16, and 18 were determined by RT-PCR assay. Location of CCR1 in the retina of rd mice at each age group was studied by immunohistochemical analysis. Expression of CCR1 in the photoreceptor cells and apoptotic cells was determined by double labeling.
  
  
  RESULTS
  Expression of CCR1 mRNA was noted in both control and rd retinas at each age group. CCR1-positive cells started to emerge in the outer nuclear layer (ONL) in rd retinas at P8 and reached a peak at P12 and P14. Double labeling of CCR1 with rhodopsin, CD11b, or TUNEL staining showed expression of CCR1 in the photoreceptor cells, rather than in the microglial cells. Partial CCR1 expression was observed in some of the apoptotic photoreceptor cells.
  
  
  CONCLUSIONS
  Expression of CCR1 in the photoreceptor cells was increased with the progress of retinal degeneration in rd mice. Activation of CCR1 may play a role in the photoreceptor apoptosis.
authors.affiliation: Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China. hzeng23@yahoo.com
authors.forename: Hui-yang
authors.initials: HY
authors.lastname: Zeng
authors.forename: Qing-jun
authors.initials: QJ
authors.lastname: Lu
authors.forename: Qian
authors.initials: Q
authors.lastname: Liu
authors.forename: Ke-Gao
authors.initials: KG
authors.lastname: Liu
authors.forename: Ning-li
authors.initials: NL
authors.lastname: Wang
mesh_terms: D000375:Aging / Q000502:physiology; D000818:Animals; D000831:Animals, Newborn; D017209:Apoptosis; D039481:CD11b Antigen / Q000378:metabolism; D019084:Fluorescent Antibody Technique, Indirect; D005786:Gene Expression Regulation / Q000502:physiology*; D020287:In Situ Nick-End Labeling; D051379:Mice; D008809:Mice, Inbred C3H; D008817:Mice, Mutant Strains; D020419:Photoreceptor Cells, Vertebrate / Q000378:metabolism / Q000473:pathology; D012333:RNA, Messenger / Q000378:metabolism; D054389:Receptors, CCR1 / Q000235:genetics* / Q000378:metabolism; D012162:Retinal Degeneration / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012243:Rhodopsin / Q000378:metabolism
chemical_list: D039481:CD11b Antigen; C515301:Ccr1 protein, mouse; D012333:RNA, Messenger; D054389:Receptors, CCR1; D012243:Rhodopsin