Inhibition of Cyclin-Dependent Kinases Improves CA1 Neuronal Survival and Behavioral Performance After Global Ischemia in the Rat

• Published in: Journal of cerebral blood flow and metabolism Vol. 22; no. 2; pp. 171 - 182
• Main Authors: Wang, Fuhu, Corbett, Dale, Osuga, Hitoshi, Osuga, Sachiko, Ikeda, Joh-E, Slack, Ruth S., Hogan, Matthew J., Hakim, Antoine M., Park, David S.
• Format: Journal Article
• Language: English
• Published: London, England SAGE Publications 01-02-2002; Lippincott Williams & Wilkins; Sage Publications Ltd
• Subjects: Animals; Behavior, Animal - drug effects; Biological and medical sciences; Body Temperature - drug effects; Brain Ischemia - physiopathology; Brain Ischemia - psychology; Cell Survival - drug effects; Cyclin-Dependent Kinases - antagonists & inhibitors; Cyclin-Dependent Kinases - metabolism; Enzyme Inhibitors - pharmacology; Flavonoids - pharmacology; Hippocampus - physiopathology; Male; Maze Learning - physiology; Medical sciences; Neurology; Neurons - physiology; Neuroprotective Agents - pharmacology; Piperidines - pharmacology; Rats; Rats, Wistar; Retinoblastoma Protein - metabolism; Swimming; Time Factors; Vascular diseases and vascular malformations of the nervous system; Neuroprotection; Delayed neuronal death; Morris water maze; Global cerebral ischemia; Cyclin-dependent kinases; Apoptosis; Nervous system diseases; Pathophysiology; Rat; Enzyme; Transferases; Rodentia; Cyclin; Cardiovascular disease; Neuroprotective agent; Cerebral disorder; Vascular disease; Vertebrata; Experimental disease; Mammalia; Ischemia; Kinase; Animal; Central nervous system disease; Cerebrovascular disease; Brain (vertebrata)
• ISSN: 0271-678X; 1559-7016
• DOI: 10.1097/00004647-200202000-00005

Increasing evidence suggests that cyclin-dependent kinases participate in neuronal death induced by multiple stresses in vitro. However, their role in cell death paradigms in vivo is not well characterized. Accordingly, the authors examined whether cyclin-dependent kinase inhibition resulted in functionally relevant and sustained neuroprotection in a model of global ischemia. Intracerebroventricular administration of the cyclin-dependent kinase inhibitor flavopiridol, immediately or at 4 hours postreperfusion after a global insult, reduced injury in the CA1 of the hippocampus when examined 7 days after reperfusion. No significant protection was observed when flavopiridol was administered 8 hours after reperfusion. The tumor-suppressor retinoblastoma protein, a substrate of cyclin-dependent kinase, was phosphorylated on a cyclin-dependent kinase consensus site after the global insult; this phosphorylation was inhibited by flavopiridol administration. Importantly, flavopiridol had no effect on core body temperature, suggesting that the mechanism of neuroprotection was through cyclin-dependent kinase inhibition but not through hypothermia. Furthermore, inhibition of cyclin-dependent kinases improved spatial learning behavior as assessed by the Morris water maze 7 to 9 days after reperfusion. However, the histologic protection observed at day 7 was absent 28 days after reperfusion. These results indicate that cyclin-dependent kinase inhibition provides an extended period of morphologic and functional neuroprotection that may allow time for other neuroprotective modalities to be introduced.