Differential Involvement of Intracellular Ca2+ in 1-Methyl-4-phenylpyridinium- or 6-Hydroxydopamine-Induced Cell Viability Loss in PC12 Cells

Abstract

1-Methyl-4-phenylpyridinium (MPP(+)) or 6-hydroxydopamine (6-OHDA) caused a nuclear damage, the mitochondrial membrane permeability changes, leading to the cytochrome c release and caspase-3 activation, the formation of reactive oxygen species and the depletion of GSH in PC12 cells. Nicardipine (a calcium channel blocker), EGTA (an extracellular calcium chelator), BAPTA-AM (a cell permeable calcium chelator) and calmodulin antagonists (W-7 and calmidazolium) attenuated the MPP(+)-induced mitochondrial damage and cell death. In contrast, the compounds did not reduce the toxicity of 6-OHDA. Treatment with MPP(+ )or 6-OHDA evoked the elevation of intracellular Ca(2+) levels. Unlike cell injury, addition of nicardipine, BAPTA-AM and calmodulin antagonists prevented the elevation of intracellular Ca(2+) levels due to both toxins. The results show that the MPP(+)-induced formation of the mitochondrial permeability transition seems to be mediated by elevation of intracellular Ca(2+) levels and calmodulin action. In contrast, the 6-OHDA-induced cell death seems to be mediated by Ca(2+)-independent manner.

Glycyrrhizin Attenuates MPTP Neurotoxicity in Mouse and MPP+-Induced Cell Death in PC12 Cells

“…ROS act upon mitochondria, causing a disruption of mitochondrial membrane potential and the release of cytochrome c (Fleury et al, 2002). It has been shown that MPP + induces the formation of ROS and nitrogen species, which is involved in mitochondrial dysfunction and cell death (Lee et al, 2006(Lee et al, , 2007. Inhibitory effect of antioxidants such as N-acetylcysteine and carboxy-PTIO on the MPP + -induced activation of caspase-3 may support the results of the previous reports.…”

“…PC12 cells upon the nerve growth factor stimulation not only display abundant neuritic growth, but also adopt a neurochemical dopaminergic phenotype (Kadota et al, 1996). The MPP + -induced apoptosis in neuronal cells is mediated by formation of the mitochondrial permeability transition, which results in the release of mitochondrial cytochrome c and subsequent activation of caspase-3 (Cassarino et al, 1999;Lee et al, 2006). In agreement with these reports, the MPP + induced cell death seems to be mediated by activation of caspase-3.…”

“…The membrane permeability transition of mitochondria is known as a central event in the course of a variety of toxic and oxidative forms of cell injury as well as apoptosis (Mignotte & Vayssiére, 1998). Along with respiratory chain inhibition, neuronal cell death by MPP + is suggested to be mediated by formation of the mitochondrial permeability transition that leads to the release of cytochrome c and activation of caspases, and by disturbance of intracellular Ca 2+ homeostasis (Cassarino et al, 1999;Lee et al, 2006Lee et al, , 2007.…”

Involvement of the mitochondrial apoptotic pathway and nitric oxide synthase in dopaminergic neuronal death induced by 6-hydroxydopamine and lipopolysaccharide

“…Several mechanisms including impaired mitochondrial complex-I activity, mitochondrial permeability transition pore (MTP) formation, increased expression of Fas and caspase activity have been reported in post-mortem brain samples of Parkinson's disease patients. [1][2][3][4][5][6][7] Moreover, in vitro studies also support a role of apoptosis in the neurotoxin induced death of neurons. 1-Methyl-4-phenylpyridinium (MPP + ) or 6-hydroxydopamine (6-OHDA) in a concentration-dependent manner increased cytochrome-c release into the cytosol, caspase's activity, uncoupling of mitochondrial oxidative phosphorylation and decreased mitochondrial membrane potential in human neuroblastoma SHSY5Y cells, PC12 cells, mesencephalic dopaminergic neurons and in MN9D dopaminergic neuronal cells has also been reported.…”

Neurocytoprotective effects of the bioactive constituents of Pueraria thomsonii in 6-hydroxydopamine (6-OHDA)-treated nerve growth factor (NGF)-differentiated PC12 cells

“…In order to avoid the photo-oxidation of DCF, we used a single rapid scan to assemble the fluorescence images, and the same settings were used for all tests. (Lee et al, 2006;Yamamoto et al, 2007) …”