Cilnidipine mediates a neuroprotective effect by scavenging free radicals and activating the phosphatidylinositol 3-kinase pathway.
We investigated the neuroprotective effect and mechanisms of action of cilnidipine, a long-acting, second-generation 1,4-dihydropyridine inhibitor of L- and N-type calcium channels, in PC12 cells that were neuronally differentiated by treatment with nerve growth factor (nPC12 cells). To evaluate the effect of cilnidipine on viability, nPC12 cells were treated with several concentrations of this drug before performing viability assays. Free radical levels and intracellular signaling proteins were measured with the fluorescent probe, 2',7'-dichlorodihydrofluorescein diacetate and western blotting, respectively. Cell viability was not affected by low concentrations of cilnidipine up to 150 microM, but it was slightly decreased at 200 microM cilnidipine. Following H(2)O(2) exposure, the viability of nPC12 cells decreased significantly; however, treatment with cilnidipine increased the viability of H(2)O(2)-injured nPC12 cells in a concentration-dependent manner. Treatment with H(2)O(2) resulted in a concentration-dependent increase in free radical levels in nPC12 cells, and cilnidipine treatment reduced free radical levels in H(2)O(2)-injured nPC12 cells in a dose-dependent manner. Cilnidipine treatment increased the expression of p85aPI3K (phosphatidylinositol 3-kinase) phosphorylated Akt, phosphorylated glycogen synthase kinase-3 (pGSK-3beta), and heat shock transcription factor (HSTF-1) which are proteins related to neuronal cell survival, and decreased levels of cytosolic cytochrome c, activated caspase 3, and cleaved poly (ADP-ribose) polymerase (PARP), which are associated with neuronal cell death, in H(2)O(2)-injured nPC12 cells. These results indicate that cilnidipine mediates its neuroprotective effects by reducing oxidative stress, enhancing survival signals (e.g., PI3K, phosphorylated Akt, pGSK-3beta, and HSTF-1), and inhibiting death signals from cytochrome c release, caspase 3 activation, and PARP cleavage.
Lee
Young Joo
YJ
Department of Neurology, Hanyang University College of Medicine, Seoul, Korea.
Park
Kee Hyung
KH
Park
Hyun-Hee
HH
Kim
Yun Jin
YJ
Lee
Kyu-Yong
KY
Kim
Seung Hyun
SH
Koh
Seong-Ho
SH
D000704:Analysis of Variance; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D002454:Cell Differentiation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D004095:Dihydropyridines / Q000737:chemistry / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions / Q000502:physiology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D016166:Free Radical Scavengers / Q000378:metabolism*; D006861:Hydrogen Peroxide / Q000494:pharmacology; D007211:Indoles; D009474:Neurons / Q000187:drug effects; D016877:Oxidants / Q000494:pharmacology; D018384:Oxidative Stress / Q000187:drug effects; D016716:PC12 Cells; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism*; D051381:Rats; D015398:Signal Transduction / Q000187:drug effects* / Q000502:physiology; D013778:Tetrazolium Salts; D013844:Thiazoles; D020960:omega-Conotoxins / Q000494:pharmacology
D002121:Calcium Channel Blockers; D004095:Dihydropyridines; D004791:Enzyme Inhibitors; D016166:Free Radical Scavengers; D007211:Indoles; D016877:Oxidants; D013778:Tetrazolium Salts; D013844:Thiazoles; D020960:omega-Conotoxins; C007293:DAPI; C078452:ziconotide; C065927:cilnidipine; D006861:Hydrogen Peroxide; D019869:Phosphatidylinositol 3-Kinases; C022616:thiazolyl blue