3-[2-[4-(3-Chloro-2-methylphenylmethyl)-1-piperazinyl]ethyl]-5,6-dimethoxy-1-(4-imidazolylmethyl)-1H-indazole dihydro-chloride 3.5 hydrate (DY-9760e) is neuroprotective in rat microsphere embolism: role of the cross-talk between calpain and caspase-3 through calpastatin.

Abstract

Microsphere embolism (ME)-induced cerebral ischemia can elicit various pathological events leading to neuronal death. Western blotting and immunohistochemical studies revealed that expression of calpastatin, an endogenous calpain inhibitor, decreased after ME induction. Calpain activation after ME was apparently due to, in part, a decrease in calpastatin in a late phase of neuronal injury. The time course of that decrease also paralleled caspase-3 activation. In vitro studies demonstrated that calpastatin was degraded by caspase-3 in a Ca(2+)/calmodulin (CaM)-dependent manner. Because CaM binds directly to calpastatin, we asked whether a novel CaM antagonist, 3-[2-[4-(3-chloro-2-methylphenylmethyl)-1-piperazinyl]ethyl]-5,6-dimethoxy-1-(4-imidazolylmethyl)-1H-indazole dihydro-chloride 3.5 hydrate (DY-9760e), inhibits caspase-3-induced calpastatin degradation during ME-induced neuronal damage. We also tested the effect of DY-9760e on degradation of fodrin, a calpain substrate. Consistent with our hypothesis, DY-9760e (25 or 50 mg/kg i.p.) treatment inhibited degradation of calpastatin and fodrin in a dose-dependent manner. Because DY-9760e showed powerful neuroprotective activity with concomitant inhibition of calpastatin degradation, cross-talk between calpain and caspase-3 through calpastatin possibly accounts for ME-induced neuronal injury. Taken together, both inhibition of caspase-3-induced calpastatin degradation and calpain-induced fodrin breakdown by DY-9760e in part mediate its neuroprotective action.

• Authors: Feng Han, Yasufumi Shirasaki, Kohji Fukunaga
• Journal: The Journal of pharmacology and experimental therapeutics (J Pharmacol Exp Ther) Vol. 317 Issue 2 Pg. 529-36 (May 2006) ISSN: 0022-3565 [Print] United States
• PMID: 16467455 (Publication Type: Journal Article)

Chemical References

• 3-(2-(4-(3-chloro-2-methylphenyl)1-piperazinyl)ethyl)5,6-dimethoxy-1-(4-imidazolylmethyl)-1H-indazol dihydrochloride 3.5 hydrate
• Calcium-Binding Proteins
• Calmodulin
• Indazoles
• Neuroprotective Agents
• calpastatin
• Calpain
• Casp3 protein, rat
• Caspase 3
• Caspases

Topics

• Animals
• Brain Ischemia (enzymology, metabolism, pathology, prevention & control)
• Calcium-Binding Proteins (biosynthesis)
• Calmodulin (antagonists & inhibitors, metabolism)
• Calpain (antagonists & inhibitors)
• Caspase 3
• Caspases (metabolism)
• Disease Models, Animal
• Dose-Response Relationship, Drug
• Enzyme Activation
• Indazoles (pharmacology, therapeutic use)
• Intracranial Embolism (complications)
• Male
• Microspheres
• Neurons (drug effects, metabolism, pathology)
• Neuroprotective Agents (pharmacology, therapeutic use)
• Protein Binding
• Rats
• Rats, Wistar