title: Comparative proteomic analysis of proteins involved in cell aggregation during neural differentiation of P19 mouse embryonic carcinoma cells.
abstract: Cell-cell interactions play a crucial role during embryogenesis and are enhanced during cell aggregation. P19 mouse embryonic carcinoma cells can differentiate into neural cells by the addition of retinoic acid (RA) or by overexpression of the Wnt1 gene, with both processes dependent on cell aggregation. To identify molecules involved in the cell aggregation process, two-dimensional gel electrophoresis (2DE) was used to establish the cell aggregation-associated protein profiles. MALDI-TOF/TOF was used to identify 71 protein spots with differential expression patterns. Among these spots, 54 were differentially expressed in both P19 and Wnt1-overexpressing P19 (Wnt1/P19) cell aggregates, with 42 proteins up-regulated and 12 proteins down-regulated. The other 17 spots were differentially expressed only in Wnt1/P19 cells. The expression patterns of 5 cell aggregation-associated proteins, N-myc downstream-regulated gene 1 (NDRG1), 14-3-3 epsilon, 14-3-3 gamma, acid calponin and cell division control protein 2 homologue (Cdc2), were confirmed by immunoblot and RT-PCR. To further investigate the relationship between cell aggregation and neural differentiation, NDRG1 expression was inhibited by RNA interference during P19 cell aggregation. Silencing of NDRG1 reduced the size of cell aggregates and the expression of N-cadherin, and it also impaired the RA-induced P19 cell neural differentiation. In conclusion, this study provides new clues for the possible mechanism underlying cell aggregation during pluripotent stem cell neural differentiation.
authors.affiliation: State Key of Molecular Biology and Laboratory of Molecular Cell Biology, Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai 200031, China.
authors.forename: Xia
authors.initials: X
authors.lastname: Gao
authors.forename: Hong-Yu
authors.initials: HY
authors.lastname: Tian
authors.forename: Li
authors.initials: L
authors.lastname: Liu
authors.forename: Mei-Lan
authors.initials: ML
authors.lastname: Yu
authors.forename: Nai-He
authors.initials: NH
authors.lastname: Jing
authors.forename: Fu-Kun
authors.initials: FK
authors.lastname: Zhao
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002449:Cell Aggregation / Q000187:drug effects / Q000502:physiology; D002454:Cell Differentiation / Q000187:drug effects / Q000502:physiology*; D045744:Cell Line, Tumor; D015180:Electrophoresis, Gel, Two-Dimensional; D054278:Embryonal Carcinoma Stem Cells / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D051379:Mice; D008969:Molecular Sequence Data; D055495:Neurogenesis / Q000187:drug effects / Q000502:physiology*; D020543:Proteome / Q000378:metabolism*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014212:Tretinoin / Q000494:pharmacology
chemical_list: D020543:Proteome; D014212:Tretinoin