title: Increased expression of beta-amyloid protein precursor and microtubule-associated protein tau during the differentiation of murine embryonal carcinoma cells.
abstract: Expression of the genes encoding the beta/A4 amyloid protein precursor (APP) and microtubule-associated protein tau was studied in an embryonal carcinoma cell line (P19) that differentiates in vitro into cholinergic neurons after treatment with retinoic acid. Expression of APP increased 34- (mRNA) and 50-fold (protein) during neuronal differentiation; APP-695 accounted for most of this increase. These remarkable increases in APP expression coincided with a proliferation of neuronal processes and with an increase in content of tau mRNA. Moreover, subsequent decreases in the levels of APP and tau mRNA coincided with the onset of the degeneration of the neuronal processes. Immunocytochemical staining suggested that greater than 85% of the P19-derived neurons are cholinergic and that APP is present in the neuronal processes and cell bodies. These results suggest that APP may play an important role in construction of neuronal networks and neuronal differentiation and also indicate that this embryonal carcinoma cell line provides an ideal model system to investigate biological functions of APP and the roles of APP and tau protein in development of Alzheimer's disease in cholinergic neurons.
authors.affiliation: Department of Pathology, University of Washington, Seattle 98195.
authors.forename: K
authors.initials: K
authors.lastname: Fukuchi
authors.forename: S S
authors.initials: SS
authors.lastname: Deeb
authors.forename: K
authors.initials: K
authors.lastname: Kamino
authors.forename: C E
authors.initials: CE
authors.lastname: Ogburn
authors.forename: A D
authors.initials: AD
authors.lastname: Snow
authors.forename: R T
authors.initials: RT
authors.lastname: Sekiguchi
authors.forename: T N
authors.initials: TN
authors.lastname: Wight
authors.forename: H
authors.initials: H
authors.lastname: Piussan
authors.forename: G M
authors.initials: GM
authors.lastname: Martin
mesh_terms: D016564:Amyloid beta-Protein Precursor / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D002454:Cell Differentiation; D003561:Cytarabine / Q000494:pharmacology; D007150:Immunohistochemistry; D051379:Mice; D008869:Microtubule-Associated Proteins / Q000378:metabolism*; D009474:Neurons / Q000473:pathology; D012333:RNA, Messenger / Q000378:metabolism; D013724:Teratoma / Q000378:metabolism* / Q000473:pathology; D014407:Tumor Cells, Cultured; D016875:tau Proteins / Q000378:metabolism*
chemical_list: D016564:Amyloid beta-Protein Precursor; D008869:Microtubule-Associated Proteins; D012333:RNA, Messenger; D016875:tau Proteins; D003561:Cytarabine