Nedd9 protein, a Cas-L homologue, is upregulated after transient global ischemia in rats: possible involvement of Nedd9 in the differentiation of neurons after ischemia.
OBJECTIVE
Some proteins involved in self-repair after stroke in the adult brain are primarily expressed during embryonic development and strongly down-regulated during the early postnatal phase. Neuronal precursor cell-expressed, developmentally down-regulated gene (Nedd) 9 was recognized to be identical to Crk-associated substrate lymphocyte type (Cas-L), a docking protein that associates with a variety of signaling molecules, such as focal adhesion kinase (FAK), proline-rich tyrosine kinase 2 (Pyk2), and Crk. We investigated the involvement of these proteins in the pathophysiology of global cerebral ischemia.


METHODS
The mouse Cas-L/Nedd9 cDNAs were cloned. The expression and function of Cas-L/Nedd9 protein in the pathogenesis of global ischemia in rats was investigated by RT-PCR, Western blot analysis, and immunohistochemistry. The neurite outgrowth of the transfectants of Nedd9 deletion mutants in PC-12 cells was also assessed to clarify the function of the Nedd9 protein.


RESULTS
Nedd9 was a splicing variant of Cas-L and was selectively induced in neurons of the cerebral cortex and hippocampus 1 to 14 days after the ischemia. Induced Nedd9 protein was tyrosine phosphorylated and was bound to FAK in dendrite and soma of neurons after the ischemia. Finally, it was demonstrated that Nedd9 promoted neurite outgrowth of PC-12 cells.


CONCLUSIONS
Our study may support the potential of Nedd9 for participation in the differentiation of neurons after global ischemia in rats.
Sasaki
Takahiro
T
Division of Clinical Immunology, Advanced Clinical Research Center, Institute of Medical Science, The University of Tokyo, Tokyo 108-8639, Japan.
Iwata
Satoshi
S
Okano
Hirotaka James
HJ
Urasaki
Yasuyo
Y
Hamada
Junichi
J
Tanaka
Hirotoshi
H
Dang
Nam H
NH
Okano
Hideyuki
H
Morimoto
Chikao
C
D048868:Adaptor Proteins, Signal Transducing; D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D015153:Blotting, Western; D002454:Cell Differentiation; D002540:Cerebral Cortex / Q000378:metabolism / Q000473:pathology; D003001:Cloning, Molecular; D003598:Cytoskeletal Proteins / Q000096:biosynthesis; D018076:DNA, Complementary / Q000378:metabolism; D003712:Dendrites / Q000473:pathology; D015536:Down-Regulation; D051418:Focal Adhesion Kinase 2 / Q000378:metabolism; D051416:Focal Adhesion Protein-Tyrosine Kinases / Q000378:metabolism; D017353:Gene Deletion; D018507:Gene Expression Regulation, Developmental; D018014:Gene Transfer Techniques; D006624:Hippocampus / Q000378:metabolism / Q000473:pathology; D015151:Immunoblotting; D007150:Immunohistochemistry; D047468:Immunoprecipitation; D047908:Intracellular Signaling Peptides and Proteins; D007511:Ischemia / Q000473:pathology*; D060588:LIM Domain Proteins; D008297:Male; D051379:Mice; D008840:Microfilament Proteins; D006899:Mixed Function Oxygenases; D008957:Models, Genetic; D008969:Molecular Sequence Data; D009154:Mutation; D020932:Nerve Growth Factor / Q000378:metabolism; D009474:Neurons / Q000378:metabolism / Q000473:pathology*; D050736:Oncogene Protein v-crk / Q000378:metabolism; D016716:PC12 Cells; D010750:Phosphoproteins / Q000096:biosynthesis* / Q000235:genetics*; D010766:Phosphorylation; D017434:Protein Structure, Tertiary; D051381:Rats; D017207:Rats, Sprague-Dawley; D012190:Retroviridae / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D014158:Transcription, Genetic; D014162:Transfection; D014443:Tyrosine / Q000737:chemistry; D015854:Up-Regulation; D000096985:Calponins
D048868:Adaptor Proteins, Signal Transducing; D003598:Cytoskeletal Proteins; D018076:DNA, Complementary; D051418:Focal Adhesion Kinase 2; D051416:Focal Adhesion Protein-Tyrosine Kinases; D047908:Intracellular Signaling Peptides and Proteins; D060588:LIM Domain Proteins; D008840:Microfilament Proteins; D006899:Mixed Function Oxygenases; D020932:Nerve Growth Factor; D050736:Oncogene Protein v-crk; D010750:Phosphoproteins; D014443:Tyrosine; C099942:NEDD9 protein, human; C455272:MICAL1 protein, human; D000096985:Calponins; C496053:Ptk2b protein, mouse