title: Calpain 3 is expressed in astrocytes of rat and Microcebus brain.
abstract: The calcium-dependent protease calpain is involved in numerous functions, including the control of cell survival, plasticity and motility. Whereas the isoforms calpain 1 and 2 have been described as ubiquitously expressed enzymes, calpain 3 has been called "muscle-specific", although trace amounts of calpain 3 mRNA have been detected by Northern blot in brain homogenates. In this study, we validated antibodies raised either against the peptides that were specific for a given isoform or the peptides present in all the three isoforms. We then used the anti-calpain 3 antibodies together with antibodies directed against cell-type-specific proteins to determine by double- and triple-labelling immunocytochemistry if the protease is expressed in specific cell populations of rat as well as lesser mouse lemur (Microcebus murinus) brain. Calpain 3 was almost exclusively found in cells displaying astrocyte morphology. These cells, most of which co-expressed glial fibrillary acidic protein, were particularly numerous close to the striatal subventricular zone (where numerous neurones forming the rostral migratory stream (RMS) towards the olfactory bulbs are generated) and the RMS itself. Other immunoreactive cells were found close to the pial surface of the forebrain, in the corpus callosum and in the dentate gyrus. Calpain 3 may be involved in astrocyte plasticity and/or motility.
authors.affiliation: EPHE Biologie Cellulaire Quantitative, INSERM EMI 12/Univ. Montpellier 2, CC 103, Place E. Bataillon, 34095 Montpellier Cedex 5, France. koenig@univ-montp2.fr
authors.forename: Norbert
authors.initials: N
authors.lastname: König
authors.forename: Fabrice
authors.initials: F
authors.lastname: Raynaud
authors.forename: Helen
authors.initials: H
authors.lastname: Feane
authors.forename: Micheline
authors.initials: M
authors.lastname: Durand
authors.forename: Nadine
authors.initials: N
authors.lastname: Mestre-Francès
authors.forename: Mireille
authors.initials: M
authors.lastname: Rossel
authors.forename: Ahmed
authors.initials: A
authors.lastname: Ouali
authors.forename: Yves
authors.initials: Y
authors.lastname: Benyamin
mesh_terms: D000818:Animals; D001253:Astrocytes / Q000737:chemistry / Q000201:enzymology*; D001921:Brain / Q000201:enzymology*; D002154:Calpain / Q000032:analysis / Q000096:biosynthesis*; D016565:Cheirogaleidae / Q000378:metabolism*; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology; D007527:Isoenzymes; D009124:Muscle Proteins; D011817:Rabbits; D051381:Rats
chemical_list: D007527:Isoenzymes; D009124:Muscle Proteins; D002154:Calpain; C491373:Capn3 protein, mouse; C491372:Capn3 protein, rat