Involvement of stathmin 1 in the neurotrophic effects of PACAP in PC12 cells.
Rat pheochromocytoma PC12 cells have been widely used to investigate the neurotrophic activities of pituitary adenylate cyclase-activating polypeptide (PACAP). In particular, PACAP has been shown to promote differentiation and to inhibit apoptosis of PC12 cells. In order to identify the mechanisms mediating these effects, we sought for proteins that are phosphorylated upon PACAP treatment. High-performance liquid chromatography and 2D gel electrophoresis analysis, coupled with mass spectrometry, revealed that stathmin 1 is strongly phosphorylated within only 5 min of exposure to PACAP. Western blot experiments confirmed that PACAP induced a robust phosphorylation of stathmin 1 in a time-dependent manner. On the other hand, PACAP decreased stathmin 1 gene expression. Investigations of the signaling mechanisms known to be activated by PACAP revealed that phosphorylation of stathmin 1 was mainly mediated through the protein kinase A and mitogen-activated protein kinase pathways. Blockage of stathmin 1 expression with small interfering RNA did not affect PC12 cell differentiation induced by PACAP but reduced the ability of the peptide to inhibit caspase 3 activity and significantly decreased its neuroprotective action. Taken together, these data demonstrate that stathmin 1 is involved in the neurotrophic effect of PACAP in PC12 cells.
Dejda
Agnieszka
A
INSERM U982, Institut Fédératif de Recherches Multidisciplinaires sur les Peptides (IFRMP 23), Université de Rouen, Mont-Saint-Aignan, France.
Chan
Philippe
P
Seaborn
Tommy
T
Coquet
Laurent
L
Jouenne
Thierry
T
Fournier
Alain
A
Vaudry
Hubert
H
Vaudry
David
D
D000595:Amino Acid Sequence; D000818:Animals; D053148:Caspase 3 / Q000378:metabolism; D002470:Cell Survival / Q000502:physiology; D016895:Culture Media, Serum-Free; D005786:Gene Expression Regulation / Q000502:physiology; D008969:Molecular Sequence Data; D016716:PC12 Cells; D051219:Pituitary Adenylate Cyclase-Activating Polypeptide / Q000502:physiology*; D051381:Rats; D050777:Stathmin / Q000037:antagonists & inhibitors / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D013997:Time Factors
D016895:Culture Media, Serum-Free; D051219:Pituitary Adenylate Cyclase-Activating Polypeptide; D050777:Stathmin; C061082:Stmn1 protein, rat; D053148:Caspase 3