Antiapoptotic effects of roscovitine in cerebellar granule cells deprived of serum and potassium: a cell cycle-related mechanism.
Neuronal apoptosis may be partly due to inappropriate control of the cell cycle. We used serum deprivation as stimulus and reduced potassium from 25 to 5mM (S/K deprivation), which induces apoptosis in cerebellar granule neurons (CGNs), to evaluate the direct correlation between re-entry in the cell cycle and apoptosis. Roscovitine (10 microM), an antitumoral drug that inhibits cyclin-dependent kinase 1 (cdk1), cdk2 and cdk5, showed a significant neuroprotective effect on CGNs deprived of S/K. S/K deprivation induced the expression of cell cycle proteins such as cyclin E, cyclin A, cdk2, cdk4 and E2F-1. It also caused CGNs to enter the S phase of the cell cycle, measured by a significant incorporation of BrdU (30% increase over control cells), which was reduced in the presence of roscovitine (10 microM). On the other hand, roscovitine modified the expression of cytochrome c (Cyt c), Bcl-2 and Bax, which are involved in the apoptotic intrinsic pathway induced by S/K deprivation. We suggest that the antiapoptotic effects of roscovitine on CGNs are due to its anti-proliferative efficacy and to an action on the mitochondrial apoptotic mechanism.
Unitat de Farmacologia i Farmacognòsia, Facultat de Farmàcia, Universitat de Barcelona, Nucli Universitari de Pedralbes, E-08028 Barcelona, Spain.
Ester
E
Verdaguer
Elvira G
EG
Jordá
Anna M
AM
Canudas
Andrés
A
Jiménez
David
D
Pubill
Elena
E
Escubedo
Jordi
J
Camarasa
Mercè
M
Pallàs
Antoni
A
Camins
D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D001973:Bromodeoxyuridine; D053148:Caspase 3; D061945:Caspase Inhibitors; D020169:Caspases / Q000378:metabolism; D002453:Cell Cycle; D002531:Cerebellum / Q000166:cytology / Q000187:drug effects*; D016895:Culture Media, Serum-Free; D004789:Enzyme Activation; D007150:Immunohistochemistry; D011188:Potassium / Q000008:administration & dosage*; D011687:Purines / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D000077546:Roscovitine
D000970:Antineoplastic Agents; D061945:Caspase Inhibitors; D016895:Culture Media, Serum-Free; D011687:Purines; D000077546:Roscovitine; C505410:Casp3 protein, rat; D053148:Caspase 3; D020169:Caspases; D001973:Bromodeoxyuridine; D011188:Potassium