title: Expression of aminopeptidase B in the developing and adult rat retina.
abstract: Aminopeptidase B (Ap-B), a ubiquitous enzyme, catalyses the amino-terminal cleavage of basic residues of peptide or protein substrates, indicating a role in precursor processing. The physiological function of Ap-B still remains an open question, even though its activity suggests that it could be involved in inflammatory processes and proliferation of tumor cells. This study was conducted to determine the expression of Ap-B in the developing and adult retina as a path to envisage physiological roles of Ap-B. RT-PCR and in situ hybridization were used to detect expression of Ap-B mRNA and activity tests, Western blotting and immunofluorescence microscopy were performed to identify and localize the enzyme in the rat retina. These biochemical and morphological methods show that Ap-B is expressed in the retina from embryo to adult. Expression level is restricted to specific layers (pigmented epithelium, outer and inner plexiform layers and ganglion cell layer) and is developmentally regulated. Moreover, a preliminary analysis indicates that Ap-B, the glucose transporter GLUT3 and choline acetyltransferase (ChAT) share a similar expression pattern in retina. Altogether, Ap-B appears predominantly expressed in neuronal cells lying in retinal layers containing neuritic extensions and synaptic junctions. Such expression is up-regulated during ontogenesis allowing to hypothesized that Ap-B participates in processes accompanying retinal neuronal cell differentiation.
authors.affiliation: Laboratoire de Biochimie des Signaux Régulateurs Cellulaires et Moléculaires, Unité Mixte de Recherche 7631, Université Pierre et Marie Curie-Centre National de la Recherche Scientifique, 96 Boulevard Raspail, 75006 Paris, France.
authors.forename: Christophe
authors.initials: C
authors.lastname: Piesse
authors.forename: Sandrine
authors.initials: S
authors.lastname: Cadel
authors.forename: Cécile
authors.initials: C
authors.lastname: Gouzy-Darmon
authors.forename: Jean-Claude
authors.initials: JC
authors.lastname: Jeanny
authors.forename: Véronique
authors.initials: V
authors.lastname: Carrière
authors.forename: Didier
authors.initials: D
authors.lastname: Goidin
authors.forename: Laurent
authors.initials: L
authors.lastname: Jonet
authors.forename: Danielle
authors.initials: D
authors.lastname: Gourdji
authors.forename: Paul
authors.initials: P
authors.lastname: Cohen
authors.forename: Thierry
authors.initials: T
authors.lastname: Foulon
mesh_terms: D000626:Aminopeptidases / Q000032:analysis* / Q000235:genetics; D000818:Animals; D015153:Blotting, Western / Q000379:methods; D002795:Choline O-Acetyltransferase / Q000235:genetics; D018507:Gene Expression Regulation, Developmental; D051274:Glucose Transporter Type 3; D017403:In Situ Hybridization / Q000379:methods; D008856:Microscopy, Fluorescence; D009004:Monosaccharide Transport Proteins / Q000235:genetics; D009419:Nerve Tissue Proteins / Q000235:genetics; D009474:Neurons / Q000201:enzymology; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D011916:Rats, Inbred F344; D017208:Rats, Wistar; D012160:Retina / Q000196:embryology / Q000201:enzymology* / Q000254:growth & development*; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D051274:Glucose Transporter Type 3; D009004:Monosaccharide Transport Proteins; D009419:Nerve Tissue Proteins; D012333:RNA, Messenger; C495690:Slc2a3 protein, rat; D002795:Choline O-Acetyltransferase; D000626:Aminopeptidases; C019721:aminopeptidase B